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  2. <head><title>Stem cells, cell culture, and culture: Issues in regeneration</title></head>
  3. <body>
  4. <h1>
  5. Stem cells, cell culture, and culture: Issues in regeneration
  6. </h1>
  7. <p>
  8. Cell renewal is a factor in all aspects of health and disease, not just in aging and the degenerative
  9. diseases. Many people are doing valid research relating to cell renewal and regeneration, but its usefulness
  10. is seriously limited by cultural and commercial constraints. By recovering some of our suppressed
  11. traditional culture, I think regenerative therapies can be developed quickly, by identifying and eliminating
  12. as far as possible the main factors that interfere with tissue renewal.
  13. </p>
  14. <p>
  15. Science grew up in the highly authoritarian cultures of western Europe, and even as it contributed to
  16. cultural change, it kept an authoritarian mystique. Any culture functions as a system of definitions of
  17. reality and the limits of possibility, and to a great extent the "laws of nature" are decreed so that they
  18. will harmonize with the recognized laws of society.
  19. </p>
  20. <p>
  21. The practical success of Newton's "laws" of motion when they were applied to ballistics and "rocket science"
  22. has led many people to value calculation, based on those laws, over evidence. In biology, the idea that an
  23. organism is "the information it contains in its DNA blueprint" is an extention of this. The organism is
  24. turned into something like a deductive expression of the law of DNA. This attitude has been disastrous.
  25. </p>
  26. <p>
  27. The old feudal idea of a divine and stable social organization was applied by some people to their idea of
  28. biological organization, in which each cell (ruled by its nucleus) had its ordained place in the organism,
  29. with the brain and the "master gland," the pituitary, ruling the subordinate organs, tissues, and cells.
  30. "Anatomy" was taught from dead specimens, microscope slides, and illustrations in books. Most biologists'
  31. thoughts about cells in organisms reflect the static imagery of their instruction. (<em>"The histological
  32. image of these tissues actually reflects an instantaneous picture of cells in a continuous flux."</em>
  33. Zajicek, 1981.)
  34. </p>
  35. <p>
  36. When a person has playful and observant interactions with natural things, both regularities and
  37. irregularities will be noticed, and in trying to understand those events, the richness of the experience
  38. will suggest an expansive range of possibilities. Perception and experimentation lead to understandings that
  39. are independent of culture and tradition.
  40. </p>
  41. <p>
  42. But the mystique of science easily imposes itself, and distracts our attention from direct interactions with
  43. things. As we learn to operate lab instruments, we are taught the kinds of results that can be expected, and
  44. the concepts that will explain and predict the results of our operations. Science, as we learn about it in
  45. schools and the mass media, is mostly a set of catechisms.
  46. </p>
  47. <p>
  48. Our theories about organisms inform our experiments with cells or tissues that have been isolated from those
  49. organisms. The conditions for growing cells in dishes are thought of as "physiological," in relation to the
  50. solution's "physiological osmolarity," "physiological pH," nutrients, oxygenation, temperature, pressure,
  51. etc. But these concepts of what is physiological derive from the monolithic ideology of the doctrinaire, and
  52. often fraudulent, mainstream of biological science.
  53. </p>
  54. <p>
  55. The catechismic nature of science has led people to expect some "break-throughs" to occur in certain areas,
  56. and as authoritarian science has grown into "big science" managed by corporations and governments, those
  57. break-throughs are generally expected to be produced by the newest and most expensive developments of "high
  58. technology."
  59. </p>
  60. <p>
  61. But looking closely at the real events and processes in the sciences in the last couple of centuries, it
  62. turns out that useful advances have been produced mainly by breaking away from authoritarian doctrines, to
  63. return to common sense and relatively simple direct observations.
  64. </p>
  65. <p>
  66. Although people were cloning animals in the 1960s, it was still widely taught that it was impossible. The
  67. students of the professors who taught that it was impossible are now saying that it requires high technology
  68. and new research.
  69. </p>
  70. <p>
  71. For the last 100 years the most authoritative view in biology has been that there are no stem cells in
  72. adults, that brains, hearts, pancreases and oocytes are absolutely incapable of regeneration. But now,
  73. people seem to be finding stem cells wherever they look, but there is a mystique of high technology involved
  74. in finding and using them.
  75. </p>
  76. <p>
  77. Whether it's deliberate or not, the emphasis on stem cell technology has the function of directing attention
  78. away from traditional knowledge, the way allopathic medicine has de-emphasized the intrinsic ability of
  79. people to recover from disease.
  80. </p>
  81. <p>
  82. This resembles the way that the Mendel-Morgan gene doctrine was used to suppress the knowledge gained from
  83. centuries of experience of plant and animal breeders, and to belittle the discoveries of Luther Burbank,
  84. Paul Kammerer, Trofim Lysenko, and Barbara McClintock. The same type of biochemical process that caused the
  85. hereditary changes those researchers studied are involved in the differentiation and dedifferentiation of
  86. stem cells that regulate healing and regeneration.
  87. </p>
  88. <p>
  89. In the 1940s, even children discussed the biological discoveries of the 1920s and 1930s, the work in
  90. regeneration and adaptation, parthenogenesis, and immortalization. The ideas of J. Loeb, T. Boveri, A.
  91. Gurwitsch, J. Needham, C.M. Child, A. Carrel, et al., had become part of the general culture.
  92. </p>
  93. <p>
  94. But that real biology was killed by a consortium of industry and government that began a little before the
  95. second world war. In 1940, the government was supporting research in chemical and biological warfare, and
  96. with the Manhattan Project the role of government became so large that all of the major research
  97. universities were affected. Shortly after the war, many researchers from the Manhattan Project were
  98. redeployed into "molecular genetics," where the engineering attitude was applied to organisms.
  99. </p>
  100. <p>
  101. The simplistic genetic dogmas were compatible with the reductionist engineering approach to the organism.
  102. The role of the government assured that the universities would subscribe to the basic scientific agenda. The
  103. atmosphere of that time was described by Carl Lindegren as "The Cold War in Biology" (1966).
  104. </p>
  105. <p>
  106. The disappearance of the field concept in developmental biology was one of the strangest events in the
  107. history of science. It didn't just fade away, it was "disappeared," in a massive undertaking of social
  108. engineering. In its absence, stem cells will seem to be a profitable technological marvel, rather than a
  109. universal life function, with a central role in everything we are and everything we do and can become.
  110. </p>
  111. <p>
  112. Many people have tried to explain aging as a loss of cells, resulting from an intrinsic inability of any
  113. cell other than a germ cell to multiply more than a certain number of times. More than 40 years ago Leonard
  114. Hayflick popularized this doctrine in its most extreme form, saying that no cell can divide more than 50
  115. times unless it is converted into a cancer cell. He and his followers claimed that they had explained why
  116. organisms must age and die. At the moment the ovum is fertilized, the clock starts ticking for the
  117. essentially mortal somatic cells.
  118. </p>
  119. <p>
  120. In 1970, it was being seriously proposed that memory was produced by the death of brain cells, in a manner
  121. analogous to the holes punched in cards to enter data into computers. The cultural dogma made it impossible
  122. to consider that learning could be associated with the birth of new cells in the adult brain.
  123. </p>
  124. <p>
  125. With the announcement in 1997 of the cloning of the sheep Dolly from a somatic cell taken from a 6 year old
  126. sheep, there was renewed interest in the idea made famous by Alexis Carrel that all cells are potentially
  127. immortal, and in the possibility of preserving the vitality of human cells. Within a few months, Hayflick
  128. began reminding the public that "In the early 1960's we overthrew this dogma after finding that normal cells
  129. do have a finite replicative capacity." ("During the first half of this century it was believed that because
  130. cultured normal cells were immortal, aging must be caused by extra-cellular events.") The way Hayflick
  131. "overthrew" more than 35 years of work at the Rockefeller Institute was by growing one type of cell, a lung
  132. fibroblast, in culture dishes, and finding that the cultures deteriorated quickly.
  133. </p>
  134. <p>
  135. To draw global conclusions about an organism's development and aging from the degenerative processes seen in
  136. a single type of cell, grown in isolation from all normal stimuli, would have been treated as nothing but
  137. wild speculation, except that it occurred within a culture that needed it. No aspect of Hayflick's cell
  138. culture system could properly be called physiological.
  139. </p>
  140. <p>
  141. Other researchers, simply by changing a single factor, caused great increases in the longevity of the
  142. cultured cells. Simply using a lower, more natural oxygen concentration, the cells were able to undergo 20
  143. more divisions. Just by adding niacin, 30 more divisions; vitamin E, 70 more divisions. Excess oxygen is a
  144. poison requiring constant adaptation.
  145. </p>
  146. <p>
  147. Hayflick also published the observation that, while the cells kept in dishes at approximately body
  148. temperature deteriorated, cells kept frozen in liquid nitrogen didn't deteriorate, and he concluded that
  149. "time" wasn't the cause of aging. When I read his comments about the frozen cells, I wondered how anyone of
  150. normal intelligence could make such stupid statements. Since then, facts that came out because of the
  151. Freedom of Information Act, cause me to believe that a financial motive guided his thoughts about his
  152. cultured fibroblasts.
  153. </p>
  154. <p>
  155. Hayflick and his followers have been attacking the idea of anti-aging medicine as quackery. But he is
  156. closely involved with the Geron corporation, which proposes that genetic alterations relating to telomeres
  157. may be able to cure cancer and prevent aging. Their claims were reported by CNN as "Scientists discover
  158. cellular 'fountain of youth'."
  159. </p>
  160. <p>
  161. The "wear and tear" doctrine of aging that derived from the ideology of the gene was reinforced and renewed
  162. by Hayflick's cell culture observations, and it continued to rule the universities and popular culture.
  163. </p>
  164. <p>
  165. But detailed investigation of skin cell growth showed that cells in the lower layer of the skin divide at
  166. least 10,000 times in a normal lifetime, and similar processes occur in the lining of the intestine. The
  167. endometrium and other highly renewable tissues just as obviously violated Hayflick's limit. Transplantation
  168. experiments showed that pieces of mammary tissue or skin tissue could survive through ten normal lifetimes
  169. of experimental animals without suffering the effects of aging.
  170. </p>
  171. <p>
  172. Even the liver and adrenal gland are now known to be continuously renewed by "cell streaming," though at a
  173. slower rate than the skin, conjunctiva, and intestine. Neurogenesis in the brain is now not only widely
  174. accepted, it is even proposed as a mechanism to explain the therapeutic effects of antidepressants
  175. (Santarelli, et al., 2003).
  176. </p>
  177. <p>
  178. August Weismann's most influential doctrine said that "somatic cells are mortal, only the germline cells are
  179. immortal," but he based the doctrine on his mistaken belief that only the "germline" cells contained all the
  180. genes of the organism. In 1885, to "refute" Darwin's belief that acquired traits could be inherited, he
  181. promulgated an absolute "barrier" between "germline" and "soma," and invented facts to show that hereditary
  182. information can flow only from the germline to the somatic cells, and not the other direction. Shortly after
  183. DNA became popular in the 1950s as "the genetic material," Weismann's barrier was restated as the Central
  184. Dogma of molecular genetics, that information flows only from DNA to RNA to protein, and never the other
  185. direction.
  186. </p>
  187. <p>
  188. It was only in 2003, after the reality of cloning was widely recognized, that a few experimenters began to
  189. investigate the origin of "germline" cells in the ovary, and to discover that they derive from somatic cells
  190. (Johnson, et al., 2004). With this discovery, the ancient knowledge that a twig (<em>klon</em>, in Greek)
  191. cut from a tree could grow into a whole tree, bearing fruit and viable seeds, was readmitted to general
  192. biology, and the Weismann barrier was seen to be an illusion.
  193. </p>
  194. <p>
  195. Millions of people have "explained" female reproductive aging as the consequence of the ovary "running out
  196. of eggs." Innumerable publications purported to show the exact ways in which that process occurs, following
  197. the Weismann doctrine. But now that it is clear that adult ovaries can give birth to new oocytes, a new
  198. explanation for female reproductive aging is needed. It is likely that the same factors that cause female
  199. reproductive aging also cause aging of other systems and organs and tissues, and that those factors are
  200. extrinsic to the cells themselves, as Alexis Carrel and others demonstrated long ago. This is a way of
  201. saying that all cells are potential stem cells. The "niche" in which new cells are born in the streaming
  202. organism, and the processes by which damaged cells are removed, are physiological issues that can be
  203. illuminated by the idea of a morphogenetic field.
  204. </p>
  205. <p>
  206. When the post-war genetic engineers took over biological research, the idea of a biophysical field was
  207. totally abandoned, but after about 15 years, it became necessary to think of problems beyond those existing
  208. within a single bacterium, namely, the problem of how an ovum becomes and embryo. Francis Crick, of DNA
  209. fame, who was educated as a physicist, revived (without a meaningful historical context) the idea of a
  210. diffusion gradient as a simple integrating factor that wouldn't be too offensive to the reductionists. But
  211. for events far beyond the scale of the egg's internal structure, for example to explain how a nerve axon can
  212. travel a very long distance to innervate exactly the right kind of cell, the diffusion of molecules loses
  213. its simplicity and plausibility. (Early in the history of experimental embryology, it was observed that
  214. electrical fields affect the direction of growth of nerve fibers.)
  215. </p>
  216. <p>
  217. C. M. Child saw a gradient of metabolic activity as an essential component of the morphogenetic field. This
  218. kind of gradient doesn't deny the existence of diffusion gradients, or other physical components of a field.
  219. Electrical and osmotic (and electro-osmotic) events are generated by metabolism, and affect other factors,
  220. including pH, oxidation and reduction, cell motility and cell shape, ionic selectivity and other types of
  221. cellular selectivity and specificity. Gradients of DNA methylation exist, and affect the expression of
  222. inherited information.
  223. </p>
  224. <p>
  225. Methylation decreases the expression of particular genes, and during the differention of cells in the
  226. development of an embryo, genes are methylated and demethylated as the cell adapts to produce the proteins
  227. that are involved in the structure and function of a particular tissue. Methylation (which increases a
  228. molecule's affinity for fats) is a widespread process in cells, and for example regulates cellular
  229. excitability. It is affected by diet and a variety of stresses.
  230. </p>
  231. <p>
  232. DNA methylation patterns are normally fairly stable, and can help to account for the transgenerational
  233. transmission of acquired adaptations, and for neonatal imprinting that can last a lifetime. But with injury,
  234. stress, and aging, the methylation patterns of differentiated tissues can be changed, contributing to the
  235. development of tumors, or to the loss of cellular functions. Even learning can change the methylation of
  236. specific genes. During <em>in vitro</em> culture, the enzymes of gene methylation are known to be increased,
  237. relative to their normal activity (Wang, et al., 2005).
  238. </p>
  239. <p>
  240. The phenomenon of "gene" methylation in response to environmental and metabolic conditions may eventually
  241. lead to the extinction of the doctrine that "cells are controlled by their genes."
  242. </p>
  243. <p>
  244. During successful adaptation to stress, cells make adjustments to their metabolic systems (for example with
  245. a holistic change of the degree of phosphorylation, which increases molecules' affinity for water), and
  246. their metabolic processes can contribute to changes in their state of differentiation. Some changes may lead
  247. to successful adaptation (for example by producing biogenic stimulators that stimulate cell functioning and
  248. regeneration), others to failed adaptation. Even the decomposition of cells can release substances that
  249. contribute to the adaptation of surrounding cells, for example when sphingosines stimulate the production of
  250. stem cells.
  251. </p>
  252. <p>
  253. DNA methylation is just one relatively stable event that occurs in relation to a metabolic field.
  254. Modifications of histones (regulatory proteins in chromosomes, which are acetylated as well as methylated)
  255. and structural-contractile filaments also contribute to the differentiation of cells, but the pattern of DNA
  256. methylation seems to guide the methylation of histones and the structure of the chromosomes (Nan, et al.,
  257. 1998).
  258. </p>
  259. <p>
  260. Steroids and phospholipids, neurotransmitters and endorphins, ATP, GTP, other phosphates, retinoids, NO and
  261. CO2--many materials and processes participate in the coherence of the living state, the living substance.
  262. Carbon dioxide, for example, by binding to lysine amino groups in the histones, will influence their
  263. methylation. Carbon dioxide is likely to affect other amino groups in the chromosomes.
  264. </p>
  265. <p>
  266. The number and arrangement of mitochondria is an important factor in producing and maintaining the metabolic
  267. gradients. Things that decrease mitochondrial energy production--nitric oxide, histamine, cytokines,
  268. cortisol--increase DNA methylation. Decreased gene expression is associated with reduced respiratory energy.
  269. It seems reasonable to guess that increased gene expression would demand increased availability of energy.
  270. </p>
  271. <p>
  272. As an ovum differentiates into an organism, cells become progressively more specialized, inhibiting the
  273. expression of many genes. Less energy is needed by stably functioning cells, than by actively adapting
  274. cells. A.I. Zotin described the process of maturing and differentiating as a decrease of entropy, an
  275. increase of order accompanying a decreased energy expenditure. The entropic egg develops into a less
  276. entropic embryo with a great expenditure of energy.
  277. </p>
  278. <p>
  279. The partially differentiated stem cell doesn't go through all the stages of development, but it does expend
  280. energy intensely as it matures.
  281. </p>
  282. <p>
  283. The restoration of energy is one requirement for the activation of regeneration. When a hormone such as
  284. noradrenaline or insulin causes a stem cell to differentiate in vitro, it causes new mitochondria to form.
  285. This is somewhat analogous to the insertion of mitochondria into the ripening oocyte, by the nurse cells
  286. that surround it. The conditionally decreased entropy of maturation is reversed, and when sufficient
  287. respiratory energy is available, the renewed and refreshed cell will be able to renew an appropriate degree
  288. of differentiation.
  289. </p>
  290. <p>
  291. When simple organisms, such as bacteria, fungi, or protozoa are stressed, for example by the absence of
  292. nutrients or the presence of toxins, they slow their metabolism, and suppress the expression of genes,
  293. increasing the methylation of DNA, to form resistant and quiescent spores. Our differentiated state doesn't
  294. go to the metabolic extreme seen in sporulation, but it's useful to look at maturity and aging in this
  295. context, because it suggests that the wrong kind of stress decreases the ability of the organism to adapt,
  296. by processes resembling those in the spore-forming organisms.
  297. </p>
  298. <p>
  299. Charles Vacanti, who has grown cartilage from cells taken from 100 year old human cartilage, believes our
  300. tissues contain "spore cells," very small cells with slow metabolism and extreme resistance to heat, cold,
  301. and starvation.
  302. </p>
  303. <p>
  304. If the slowed metabolism of aging, like that of sporulating cells, is produced by a certain kind of stress
  305. that lowers cellular energy and functions, it might be useful to think of the other stages of the stress
  306. reaction in relation to the production of stem cells. Selye divided stress into a first stage of shock,
  307. followed by a prolonged adaptation, which could sometimes end in exhaustion. If the maturity of
  308. differentiated functioning is equivalent to the adaptation phase, and cellular decline and disintegration is
  309. the exhaustion phase, then the shock-like reaction would correspond to the birth of new stem cells.
  310. </p>
  311. <p>
  312. Selye described estrogen's effects as equivalent to the shock-phase of stress. Estrogen's basic action is to
  313. make oxygen unavailable, lowering the oxygen tension of the tissues, locally and temporarily. Like nitric
  314. oxide, which is produced by estrogenic stimulation, estrogen interferes with energy production, so if its
  315. stimulation is prolonged, cells are damaged or killed, rather than being stimulated to regenerate.
  316. </p>
  317. <p>
  318. Extrinsic factors elicit renewal, the way stress can elicit adaptation. While aging cells can't use the
  319. oxygen that is present, a scarcity of oxygen can serve as a stimulus to maximize the respiratory systems.
  320. Brief oxygen deprivation excites a cell, causes it to swell, and to begin to divide.
  321. </p>
  322. <p>
  323. Oxygen deprivation, as in the normally hypoxic bone marrow, stimulates the formation of stem cells, as well
  324. as the biogenesis of mitochondria. As the newly formed cells, with abundant mitochondria, get adequate
  325. oxygen, they begin differentiation.
  326. </p>
  327. <p>
  328. Form, based on cellular differentiation, follows function--a vein transplanted into an artery develops
  329. anatomically into an artery, a colon attached directly to the anus becomes a new rectum with its appropriate
  330. innervation, a broken bone restructures to form a normal bone. If the bladder is forced to function more
  331. than normal, by artificially keeping it filled, its thin wall of smooth muscle develops into a thick wall of
  332. striated muscle that rhythmically contracts, like the heart. If a tadpole is given a vegetarian diet, the
  333. absorptive surface of its digestive system will develop to be twice the size of those that are fed meat.
  334. Pressure, stretching, and pulsation are among the signals that guide cells' differentiation.
  335. </p>
  336. <p>
  337. Very early in the study of embryology it was noticed that the presence of one tissue sometimes induced the
  338. differentiation of another kind, and also that there were factors in embryonic tissues that would stimulate
  339. cell division generally, and others that could inhibit the growth of a particular tissue type. Diffusable
  340. substances and light were among the factors identified as growth regulators.
  341. </p>
  342. <p>
  343. Extracts of particular tissues were found to suppress the multiplication of cells in that type of tissue, in
  344. adult animals as well as in embryos. In the 1960s, the tissue-specific inhibitors were called chalones.
  345. </p>
  346. <p>
  347. The brain's development is governed by the presence in the organism of the body part to which it
  348. corresponds, such as the eyes or legs. The number of cells in a particular part of the nervous system is
  349. governed by the quantity of nervous input, sensory or motor, that it receives. An enriched environment
  350. causes a bigger brain to grow. Sensory nerve stimulation of a particular region of the brain causes nerve
  351. cells to migrate to that area (a process called neurobiotaxis; deBeers, 1927), but nerve stimulation also
  352. causes mitochondria to accumulate in stimulated areas. Nerve activity has a trophic, sustaining influence on
  353. other organs, as well as on the brain. Nerve stimulation, like mechanical pressure or stretching, is an
  354. important signal for cellular differentiation.
  355. </p>
  356. <p>
  357. When stem cells or progenitor cells are called on to replace cells in an organ, they are said to be
  358. "recruited" by that organ, or to "home" to that organ, if they are coming from elsewhere. Traditionally, the
  359. bone marrow has been considered to be the source of circulating stem cells, but it now appears that a
  360. variety of other less differentiated cells can be recruited when needed. Cells from the blood can repair the
  361. endothelium of blood vessels, and endothelial cells can become mesenchymal cells, in the heart, for example.
  362. </p>
  363. <p>
  364. The standard doctrine about cancer is that a tumor derives from a single mutant cell, but it has been known
  365. for a long time that different types of cell, such as phagocytes and mast cells, usually reside in tumors,
  366. and it is now becoming clear that tumors recruit cells, including apparently normal cells, from other parts
  367. of the same organ. For example, a brain tumor of glial cells, a glioma, recruits glial cells from
  368. surrounding areas of the brain, in a process that's analogous to the embryological movement of nerve cells
  369. to a center of excitation. Each tumor, in a sense, seems to be a center of excitation, and its fate seems to
  370. depend on the nature of the cells that respond to its signals.
  371. </p>
  372. <p>
  373. To accommodate some of the newer facts about tumors, the cancer establishment has begun speaking of "the
  374. cancer stem cell" as the real villain, the origin of the tumor, while the bulk of the tumor is seen to be
  375. made up of defective cells that have a short life-span. But if we recognize that tumors are recruiting cells
  376. from beyond their boundaries, this process would account for the growth and survival of a tumor even while
  377. most of its cells are inert and dying, without invoking the invisible cancer stem cell. And this view, that
  378. it is the field which is defective rather than the cell, is consistent with the evidence which has been
  379. accumulating for 35 years that tumor cells, given the right environment, can differentiate into healthy
  380. cells. (Hendrix, et al., 2007)
  381. </p>
  382. <p>
  383. Simply stretching an organ (Woo, et al., 2007) is stimulus enough to cause it to recruit cells from the
  384. bloodstream, and will probably stimulate multiplication in its local resident cells, too. Every "cancer
  385. field" probably begins as a healing process, and generally the healing and regeneration are at least
  386. partially successful.
  387. </p>
  388. <p>
  389. When an organ--the brain, heart, liver, or a blood vessel--is inflamed or suffering from an insufficient
  390. blood supply, stem cells introduced into the blood will migrate specifically to that organ.
  391. </p>
  392. <p>
  393. Organ specific materials (chalones) are known to circulate in the blood, inhibiting cell division in cells
  394. typical to that organ, but it also seems that organ specific materials are secreted by a damaged organ, that
  395. help to prepare stem cells for their migration into that organ. When undifferentiated cells are cultured
  396. with serum from a person with liver failure, they begin to differentiate into liver cells.
  397. </p>
  398. <p>
  399. It is still common to speak of each organ as having a "clonal origin" in the differentiating embryo, as a
  400. simple expansion of a certain embryonic anlage. The implication of this way of thinking is that
  401. differentiation is <em>determination</em> in an irreversible sense. This is another case of medical ideas
  402. being based on images of fixed histological material. Normal cells, including nerve and muscle cells, can
  403. change type, with connective tissue cells becoming nerve cells, nerve cells becoming muscle and fiber cells,
  404. fat, fiber, and muscle cells redifferentiating, for example.
  405. </p>
  406. <p>
  407. Cell movements in solid tissues aren't limited to the short distances between capillaries and the tissues
  408. nourished by those capillaries, rather, cells can migrate much greater distances, without entering the
  409. bloodstream. The speed of a single cell moving by ameboid motion can be measured by watching cells on a
  410. glass slide as they move toward food, or by watching cells of the slime mold Dictyostelium when they are
  411. aggregating, or by watching the pigment cells in and around moles or melanomas, under the influence of
  412. hormones. At body temperature, a single cell can crawl about an inch per day. Waves or spots of brown
  413. pigment can be seen migrating through the skin away from a mole, preceding the disintegration of the mole
  414. under the influence of progesterone or DHEA. Under ordinary conditions, pigment cells can sometimes be seen
  415. migrating into depigmented areas of skin, during the recovery of an area affected by vitiligo. These
  416. organized movements of masses of cells happen to be easy to see, but there is evidence that other types of
  417. cell can reconstruct tissues by their ameboid movements, when circumstances are right. Tumors or tissue
  418. abnormalities can appear or disappear with a suddenness that seems impossible to people who have studied
  419. only fixed tissue preparations.
  420. </p>
  421. <p>
  422. Stimulation is anabolic, building tissue, when the organism is adapting to the stimulation. Unused
  423. structures in cells and tissues are always being recycled by metabolic processes. When tissues are injured
  424. and become unable to function, some of their substances stimulate the growth of replacement cells.
  425. </p>
  426. <p>
  427. Some types of injury or irritation can activate regenerative processes. A dermatology journal described the
  428. case of an old man who had been bald for many years who fell head-first into his fireplace. As his burned
  429. scalp healed, new hair grew. In the U.S., experimenters (Ito, et al., 2007) have found that injuring the
  430. skin of mice stimulates the formation of stem cells that are able to become hair follicle cells, supporting
  431. the regeneration of cells that had been absent. A brief exposure to estrogen, and other stress related
  432. signals (nitric oxide, endorphin, prostaglandins) can initiate stem cell proliferation.
  433. </p>
  434. <p>
  435. In the years after the first world war, Vladimir Filatov, who developed techniques of reconstructive
  436. surgery, including corneal transplants, found that cold storage of tissues (for example, corneas from
  437. cadavers) caused them to function better than fresh tissues, and he found that these stressed tissues would
  438. often spread a healing influence out into the surrounding tissues. Extracts of stressed tissues produced
  439. similar effects.
  440. </p>
  441. <p>
  442. L.V. Polezhaev began studying the regenerative capacities of mammals in the late 1940s, and his work showed
  443. that processes similar to embryonic induction are involved in the organism's responses to damaged tissues.
  444. For example, when a piece of killed muscle tissue is enclosed in a capsule ("diffusion chamber") that
  445. permits molecules, but no cells, to diffuse through it, and implanted subcutaneously, it had no inductive
  446. effect on surrounding cells. But when the pores of the capsule allowed cells to enter, skeletal muscle
  447. formed where the dead tissue had been, and tissue resembling heart muscle formed outside the capsule.
  448. Phagocytosis had been essential for the induction to occur.
  449. </p>
  450. <p>
  451. Macrophages are ordinarily thought of as "antigen-presenting cells" that help to activate the specific
  452. immune responses. But apparently phagocytosis is involved in the replacement of damaged tissues, by
  453. recruiting or inducing the differentiation of replacement cells. The phagocytosis function isn't limited to
  454. the blood cells commonly called phagocytes; even nerve cells can ingest particles and fragments of damaged
  455. tissues.
  456. </p>
  457. <p>
  458. Many factors regulate the process of phagocytosis. Stress and lipid peroxidation decrease phagocytosis
  459. (Izg"t-Uysal, et al., 2004), and also damage mitochondria and inhibit cell renewal.
  460. </p>
  461. <p>
  462. Unsaturated fatty acids inhibit phagocytosis (Guimaraes, et al., 1991, 1992; Costa Rosa, et al., 1996;
  463. Virella, et al., 1989; Akamatsu, et al., 1990), and suppress mitochondrial function (Gomes, et al., 2006).
  464. Dietary restriction activates phagocytosis (Moriguchi, et al., 1989), suggesting that normal diets contain
  465. suppressive materials.
  466. </p>
  467. <p>
  468. Subnormal temperatures cause a shift from phagocytosis to inflammation. Light, especially the red light
  469. which penetrates easily into tissues, activates the formation of new cells as well as their differentiation.
  470. It affects energy production, increasing the formation of mitochondria, and the activity of the DNA
  471. methyltransferase enzymes. Red light accelerates wound healing, and improves the quality of the scar,
  472. reducing the amount of fibrosis. The daily cycling between darkness and light is probably an important
  473. factor in regulating the birth and differentiation of cells.
  474. </p>
  475. <p>
  476. Darkness suppresses mitochondrial function, and light activates it. Prolonged darkness increases cortisol,
  477. and cortisol (which makes cells more susceptible to excitotoxic death) inhibits stem cell proliferation (Li,
  478. et al., 2006; Liu, et al., 2003). Neurogenesis is suppressed by stress, and increased by spontaneous
  479. activity, and has a circadian rhythm. Aging and depression both involve a diminished ability to rhythmically
  480. lower the production of cortisol. Cell renewal requires a rhythmic decrease in the exposure to cortisol..
  481. </p>
  482. <p>
  483. In the spring, with increased day length, the brains of song-birds grow, with an increased proliferation of
  484. cells in the part of the brain involved in singing. The production of progesterone increases in most animals
  485. in the spring, and it is the main hormone responsible for the birds' brain growth.
  486. </p>
  487. <p>
  488. Progesterone and its metabolites protect brain cells against injury, and improve the brain's ability to
  489. recover after traumatic injury (Brinton and Wang, 2006). In the 1960s, Marion Diamond's group showed that
  490. environmental enrichment, or progesterone, caused brains to grow larger, and that these changes were passed
  491. on to descendants in a cumulative, increasing way. This suggests that the factors that promote neurogenesis
  492. also cause changes in the apparatus of reproduction and inheritance, that support the development of the
  493. brain--probably including the methylation system, which is involved in regulating genes, and also mood and
  494. behavior.
  495. </p>
  496. <p>
  497. Women's monthly cycles, in which a brief estrogen dominance is followed by sustained exposure to
  498. progesterone, are probably an important factor in the renewal of the cells of the brain and other organs, as
  499. well as those of the reproductive organs. The daily rhythms of hormones and metabolism are known to be
  500. involved in the regulation of cell renewal.
  501. </p>
  502. <p>
  503. Environmental enrichment, learning, high altitude, and thyroid hormone promote the formation of new
  504. mitochondria, and stimulate stem cell proliferation. At least in some laboratories, 20% oxygen,
  505. approximately the amount as in the atmosphere, suppresses the proliferation of stem cells (He, et al.,
  506. 2007). This was the unphysiologically high concentration of oxygen used in Hayflick's cell cultures. At high
  507. altitudes, where tissues are exposed to less oxygen, and more carbon dioxide, there is a lower incidence of
  508. all the degenerative diseases, including cancer, heart disease, and dementia. Improved cellular energy
  509. production and more active renewal of cells would probably account for those differences.
  510. </p>
  511. <p>
  512. For Crick, the idea of a diffusion gradient to explain embryonic development was simply an extension of his
  513. reductionist orientation, in which diffusing molecules induced or inhibited bacterial genes, and in which
  514. genes controlled cells. For people with that orientation, the adaptive mutations described by Carl
  515. Lindegren, and later by John Cairns, or even the stress-induced variability described by Lysenko, Strong,
  516. and McClintock, were heretical. Polezhaev's demonstration that cells could do something that molecular
  517. diffusion didn't do, threatened to take biology away from the reductionists. If the organism's adaptation to
  518. the environment involves changing its own genes, Crick's paradigm fails.
  519. </p>
  520. <p>
  521. Crick's Central Dogma, derived from the ideology that produced Weismann's Barrier, has been invoked by
  522. generations of professors who wanted to deny the possibility of adaptive tissue renewal and regeneration.
  523. Without the dogma, new ideas about aging and disease will be needed. If somatic cells can adjust their
  524. genes, and if they can also differentiate into new eggs and sperms, new ideas about inheritance of acquired
  525. traits will be needed.
  526. </p>
  527. <p>
  528. The replacement of injured cells means that mutations need not accumulate. Cell renewal with elimination of
  529. mutant cells has been observed in sun-damaged skin simply by stopping the damage, and mitochondria with
  530. damaged DNA can be replaced by healthy mitochondria simply by doing the right kind of exercise.
  531. </p>
  532. <p>
  533. The regulation of cell renewal probably involves all of the processes of life, but there are a few simple,
  534. interacting factors that suppress renewal. The accumulation of polyunsaturated fats, interacting with a high
  535. concentration of oxygen, damages mitochondria, and causes a chronic excessive exposure to cortisol. With
  536. mitochondrial damage, cells are unable to produce the progesterone needed to oppose cortisol and to protect
  537. cells.
  538. </p>
  539. <p>
  540. Choosing the right foods, the right atmosphere, the right mental and physical activities, and finding the
  541. optimal rhythms of light, darkness, and activity, can begin to alter the streaming renewal of cells in all
  542. the organs. Designing a more perfect environment is going to be much simpler than the schemes of the genetic
  543. engineers.
  544. </p>
  545. <p><h3>REFERENCES</h3></p>
  546. <p>
  547. Growth 43, 58-61, 1979. <strong>The effect of progesterone on brain and body growth of chick
  548. embryos.</strong> G. Ahmad and S. Zamenhof. [This showed that progesterone, added during the time of
  549. active neuronal proliferation, increased the chicks' brain weight, while the stress hormone, corticosterone,
  550. reduced the weight.]
  551. </p>
  552. <p>
  553. J Invest Dermatol. 1990 Sep;95(3):271-4. <strong>Suppressive effects of linoleic acid on neutrophil oxygen
  554. metabolism and phagocytosis.</strong> Akamatsu H, Komura J, Miyachi Y, Asada Y, Niwa Y.
  555. </p>
  556. <p>
  557. Curr Alzheimer Res. 2006 Feb;3(1):11-7. <strong>Preclinical analyses of the therapeutic potential of
  558. allopregnanolone to promote neurogenesis in vitro and in vivo in transgenic mouse model of Alzheimer's
  559. disease.</strong> Brinton RD, Wang JM. "Herein, we present data to support a preclinical proof of
  560. concept for the therapeutic potential of allopregnanolone to promote neurogenesis. Our recent work has
  561. demonstrated that the neuroactive progesterone metabolite, allopregnanolone
  562. (3alpha-hydroxy-5alpha-pregnan-20-one), (APalpha) induced, in a dose dependent manner, a significant
  563. increase in proliferation of neuroprogenitor cells (NPCs) derived from the rat hippocampus and human neural
  564. stem cells (hNSM) derived from the cerebral cortex [1]." "The in vitro and in vivo neurogenic properties of
  565. APalpha coupled with a low molecular weight, easy penetration of the blood brain barrier and lack of
  566. toxicity, are key elements required for developing APalpha as a neurogenic / regenerative therapeutic for
  567. restoration of neurons in victims of Alzheimer's disease."
  568. </p>
  569. <p>
  570. Arch Biochem Biophys. 1996 Jan 1;325(1):107-12.<strong>
  571. Thyromimetic action of the peroxisome proliferators clofibrate, perfluorooctanoic acid, and
  572. acetylsalicylic acid includes changes in mRNA levels for certain genes</strong>
  573. <strong>
  574. involved in mitochondrial biogenesis.</strong> Cai Y, Nelson BD, Li R, Luciakova K, dePierre JW.
  575. </p>
  576. <p>
  577. Biochem Mol Biol Int. 1996 Nov;40(4):833-42. <strong>The effect of N-3 PUFA rich diet upon macrophage and
  578. lymphocyte metabolism and function.</strong> Costa Rosa LF, Safi DA, Guimar"es AR.
  579. </p>
  580. <p>
  581. G. R. de Beer, <strong><em>An Introducton to Experimental Embryology,</em></strong>
  582. Oxford, 1926.
  583. </p>
  584. <p>
  585. Biol. Rev. 1927;2:137-197, <strong>The mechanics of verterate development. </strong>
  586. de Beer GR.
  587. </p>
  588. <p>
  589. Vrach delp. 1937, 20: 803-820. <strong>Summary of 20 years' achievements in ophthalmology.</strong>
  590. Filatov VP.
  591. </p>
  592. <p>
  593. Vestnik oftal. 1938, 12: 107-159.<strong>
  594. Tissue transplantation in intra-ocular diseases.</strong> Filatov VP.
  595. </p>
  596. <p>
  597. Med zhur 1937, 9: 847-853.<strong>
  598. Intramuscular injections of cod liver oil in therapy of pigmented retinitis.</strong> Filatov VP,
  599. Verbitska E A.
  600. </p>
  601. <p>
  602. Am Rev Soviet Med. 1946, 3: 388-395.<strong>
  603. The treatment of retinitis pigmentosa with intramuscular injection of cod liver oil.</strong>
  604. Filatov VP, Verbitska EA.
  605. </p>
  606. <p>
  607. Am Rev Soviet Med 1946, 3: 395-397. <strong>Retinitis pigmentosa.</strong> Filatov VP.
  608. </p>
  609. <p>
  610. Am Rev Soviet Med 1946, 3: 397-398.<strong>
  611. The implantation of preserved placenta in retinitis pigmentosa.</strong> Filatov VP Verbitska EA.
  612. </p>
  613. <p>
  614. Hippocampus. 2006;16(3):225-32.<strong>
  615. Gonadal hormone modulation of hippocampal neurogenesis in the adult.
  616. </strong>Galea LA, Spritzer MD, Barker JM, Pawluski JL. <strong>
  617. Estradiol, the most potent estrogen, initially enhances and subsequently suppresses cell proliferation
  618. in the dentate gryus of adult female rodents.</strong>
  619. </p>
  620. <p>
  621. Glia. 1999 Feb 1;25(3):247-55. <strong>Cerebellar astrocytes treated by thyroid hormone modulate neuronal
  622. proliferation.</strong> Gomes FC, Maia CG, de Menezes JR, Neto VM. "Thyroid hormones are important for
  623. neurogenesis and gliogenesis during brain development. We have previously demonstrated that triiodothyronine
  624. (T3) treatment induced proliferation in primary culture astrocytes derived from the cerebellum of neonatal
  625. rats." "Interestingly, the cerebellar neuronal population increased by 60-80% in T3CM."
  626. </p>
  627. <p>
  628. Biochem Int. 1992 Jun;27(1):9-16. <strong>Metabolic and functional changes in macrophages of rats fed
  629. polyunsaturated or saturated fatty acid rich-diets during ageing.
  630. </strong>Guimar"es AR, Costa Rosa LF, Safi DA, Curi R.
  631. </p>
  632. <p>
  633. Biochem Int. 1991 Feb;23(3):533-43. <strong>Effect of polyunsaturated (PUFA n-6) and saturated fatty
  634. acids-rich diets on macrophage metabolism and function.</strong>
  635. Guimar"es AR, Costa Rosa LF, Sitnik RH, Curi R.
  636. </p>
  637. <p>
  638. Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2007 Apr;15(2):433-6. <strong>[Effect of hypoxia on mesenchymal stem
  639. cells - review.]</strong> [Article in Chinese] He MC, Li J, Zhao CH.
  640. </p>
  641. <p>
  642. Nat Rev Cancer. 2007 Apr;7(4):246-55. <strong>Reprogramming metastatic tumour cells with embryonic
  643. microenvironments.</strong> Hendrix MJ, Seftor EA, Seftor RE, Kasemeier-Kulesa J, Kulesa PM, Postovit
  644. LM. "Aggressive tumour cells share many characteristics with embryonic progenitors, contributing to the
  645. conundrum of tumour cell plasticity." "This Review will summarize the embryonic models used to reverse the
  646. metastatic melanoma phenotype, and highlight the prominent signalling pathways that have emerged as
  647. noteworthy targets for future consideration."
  648. </p>
  649. <p>
  650. FEBS Lett. 1973 May 15;32(1):1-8.<strong>
  651. Chalones. Specific endogenous mitotic inhibitors.</strong> Houck JC, Hennings H.
  652. </p>
  653. <p>
  654. Med Hypotheses. 2005;64(6):1138-43. <strong>Melatonin seems to be a mediator that transfers the
  655. environmental stimuli to oocytes for inheritance of adaptive changes through epigenetic inheritance
  656. system.</strong> Irmak MK, Topal T, Oter S.
  657. </p>
  658. <p>
  659. Nature. 2007 May 17;447(7142):316-20. <strong>Wnt-dependent de novo hair follicle regeneration in adult
  660. mouse skin after wounding.
  661. </strong>
  662. Ito M, Yang Z, Andl T, Cui C, Kim N, Millar SE, Cotsarelis G.
  663. </p>
  664. <p>
  665. Cell Biol Int. 2004;28(7):517-21. <strong>Effect of stress-induced lipid peroxidation on functions of rat
  666. peritoneal macrophages.</strong> Izg"t-Uysal VN, Tan R, B"lb"l M, Derin N.
  667. </p>
  668. <p>
  669. J Cereb Blood Flow Metab. 2007 Mar 28;<strong>
  670. Regeneration and plasticity in the brain and spinal cord.</strong> Johansson BB.
  671. </p>
  672. <p>
  673. Nature, 428, 145 - 150, (2004). Johnson, J., Canning, J., Kaneko, T., Pru, J.K. &amp; Tilly, J.L.
  674. </p>
  675. <p>
  676. Annals of Ophthalmology No. 1, 2005, p. 54, <strong>Life devoted to fight against blindness</strong> (on the
  677. 130th birthday anniversary of V. P. Filatov) Knopov M. Sh., Klyasov A. V.
  678. </p>
  679. <p>
  680. R. Levi-Montalcini, <strong>"Neuronal regeneration in vitro," </strong>
  681. pages 54-65 in Windle,<em> Regeneration in the Central Nervous System,</em>
  682. C. C. Thomas, 1955.
  683. </p>
  684. <p>
  685. Neurobiol Aging. 2006 Nov;27(11):1705-14. Epub 2005 Nov 4.<strong>
  686. Salivary cortisol and memory function in human aging.</strong> Li G, Cherrier MM, Tsuang DW, Petrie EC,
  687. Colasurdo EA, Craft S, Schellenberg GD, Peskind ER, Raskind MA, Wilkinson CW.
  688. </p>
  689. <p>
  690. Med Hypotheses. 2007 Mar 27; [Epub ahead of print] <strong>Effects of hypoxia on proliferation and
  691. differentiation of myoblasts.</strong> Li X, Zhu L, Chen X, Fan M.
  692. </p>
  693. <p>
  694. Exp Neurol. 2003 Nov;184(1):196-213. <strong>Suppression of hippocampal neurogenesis is associated with
  695. developmental stage, number of perinatal seizure episodes, and glucocorticosteroid level.</strong> Liu
  696. H, Kaur J, Dashtipour K, Kinyamu R, Ribak CE, Friedman LK.
  697. </p>
  698. <p>
  699. J Nutr Sci Vitaminol (Tokyo). 1989 Feb;35(1):49-59.<strong>
  700. Effects of dietary restriction on cellular immunity in rats.</strong> Moriguchi S, Toba M, Kishino Y.
  701. </p>
  702. <p>
  703. Nature. 1998 May 28;393(6683):386-9. <strong>Transcriptional repression by the methyl-CpG-binding protein
  704. MeCP2 involves a histone deacetylase complex.</strong> Nan X, Ng HH, Johnson CA, Laherty CD, Turner BM,
  705. Eisenman RN, Bird A.
  706. </p>
  707. <p>
  708. L. V. Polezhaev and E. N. Karnaukhova, <strong>"Stimulation of physiologic regeneration of nervous tissue of
  709. the cerebral cortex and its significance for biogenic therapy of neuro-mental diseases," pages 86-116 in
  710. </strong>
  711. <em>Sbornik: Klinicheskie eksperimentalnye osnovy biogennoi terapii psikhozov</em>,<strong> </strong>
  712. 1962.
  713. </p>
  714. <p>
  715. Doklady AN SSSR 150, 430-433, 1963., <strong>"Stimulation of nerve cell reproduction of cerebral cortex in
  716. mammals,"</strong> L. V. Polezhaev and E. N. Karnaukhove
  717. </p>
  718. <p>
  719. L. V. Polezhaev, <strong><em>Loss and Restoration of Regenerative Capacity in Tissues and Organs of
  720. Animals,</em></strong> page 219, 1972.
  721. </p>
  722. <p>
  723. J Hirnforsch 1991;32(5):659-664. <strong>Normalization of protein synthesis and the structure of brain
  724. dystrophic neurons after the action of hypoxia, 10% NaCl and organ-specific RNA.</strong> Polezhaev LV,
  725. Cherkasova LV, Vitvitsky VN, Timonin AV <strong>"Transplantation of embryonic nervous tissue (ENT) in one of
  726. the hemispheres normalizes all the above abnormalities observed in some neurologic and mental diseases
  727. in humans."</strong>
  728. <strong>
  729. "At the beginning 10% NaCl increased the destruction of brain cortical neurons and then stimulated
  730. protein synthesis in them.</strong> RNA injections stimulated the synthesis in cortical neurons and
  731. normalized their structure. Thus, we propose a safe and simple method for normalization of dystrophic
  732. neurons which can be used after certain improvement for curing neurodegenerative and neuropsychic diseases
  733. in humans."
  734. </p>
  735. <p>
  736. Science. 2003 Aug 8;301(5634):757. <strong>Requirement of hippocampal neurogenesis for the behavioral
  737. effects of antidepressants.</strong> Santarelli L, Saxe M, Gross C, Surget A, Battaglia F, Dulawa S,
  738. Weisstaub N, Lee J, Duman R, Arancio O, Belzung C, Hen R.
  739. </p>
  740. <p>
  741. Chin J Traumatol. 2002 Aug;5(4):246-9. <strong>Experimental study on He-Ne laser irradiation to inhibit scar
  742. fibroblast growth in culture.</strong>
  743. Shu B, Wu Z, Hao L, Zeng D, Feng G, Lin Y.
  744. </p>
  745. <p>
  746. J Cell Biochem 2001; 80:455-60.<strong>
  747. Identification and initial characterization of spore-like cells in adult mammals.</strong> Vacanti, M.
  748. P., A. Roy, J. Cortiella, L. Bonassar, and C. A. Vacanti.
  749. </p>
  750. <p>
  751. Am J Ophthalmol 1947, 30: 635-636. <strong>Biogenic Stimulators.</strong> (Editorial) Vail D.
  752. </p>
  753. <p>
  754. Clin Immunol Immunopathol. 1989 Aug;52(2):257-70.<strong>
  755. Depression of humoral responses and phagocytic functions in vivo and in vitro by fish oil and
  756. eicosapentanoic acid.</strong> Virella G, Kilpatrick JM, Rugeles MT, Hyman B, Russell R.
  757. </p>
  758. <p>
  759. Reprod Biomed Online. 2005 May;10(5):607-16.<strong>
  760. Gene expression in the preimplantation embryo: in-vitro developmental changes.
  761. </strong>
  762. Wang S, Cowan CA, Chipperfield H, Powers RD.
  763. </p>
  764. <p>
  765. Tissue Eng. 2006 Oct 1; [Epub ahead of print]<strong>
  766. Effects of Glutamine, Glucose, and Oxygen Concentration on the Metabolism and Proliferation of Rabbit
  767. Adipose-Derived Stem Cells.</strong> Follmar KE, Decroos FC, Prichard HL, Wang HT, Erdmann D, Olbrich
  768. KC.
  769. </p>
  770. <p>
  771. J Urol. 2007 Apr;177(4):1568-72. <strong>Over expression of stem cell homing cytokines in urogenital organs
  772. following vaginal distention.</strong> Woo LL, Hijaz A, Kuang M, Penn MS, Damaser MS, Rackley RR.
  773. </p>
  774. <p>
  775. Med Hypotheses. 1981 Oct;7(10):1241-51. <strong>The histogenesis of glandular neoplasia.</strong> Zajicek G.
  776. </p>
  777. <h1>
  778. <strong>Stem cells, cell culture, and culture: Issues in regeneration
  779. </strong>
  780. </h1>
  781. <p>
  782. Cell renewal is a factor in all aspects of health and disease, not just in aging and the degenerative
  783. diseases. Many people are doing valid research relating to cell renewal and regeneration, but its usefulness
  784. is seriously limited by cultural and commercial constraints. By recovering some of our suppressed
  785. traditional culture, I think regenerative therapies can be developed quickly, by identifying and eliminating
  786. as far as possible the main factors that interfere with tissue renewal.
  787. </p>
  788. <p>
  789. Science grew up in the highly authoritarian cultures of western Europe, and even as it contributed to
  790. cultural change, it kept an authoritarian mystique. Any culture functions as a system of definitions of
  791. reality and the limits of possibility, and to a great extent the "laws of nature" are decreed so that they
  792. will harmonize with the recognized laws of society.
  793. </p>
  794. <p>
  795. The practical success of Newton's "laws" of motion when they were applied to ballistics and "rocket science"
  796. has led many people to value calculation, based on those laws, over evidence. In biology, the idea that an
  797. organism is "the information it contains in its DNA blueprint" is an extention of this. The organism is
  798. turned into something like a deductive expression of the law of DNA. This attitude has been disastrous.
  799. </p>
  800. <p>
  801. The old feudal idea of a divine and stable social organization was applied by some people to their idea of
  802. biological organization, in which each cell (ruled by its nucleus) had its ordained place in the organism,
  803. with the brain and the "master gland," the pituitary, ruling the subordinate organs, tissues, and cells.
  804. "Anatomy" was taught from dead specimens, microscope slides, and illustrations in books. Most biologists'
  805. thoughts about cells in organisms reflect the static imagery of their instruction. (<em>"The histological
  806. image of these tissues actually reflects an instantaneous picture of cells in a continuous flux."</em>
  807. Zajicek, 1981.)
  808. </p>
  809. <p>
  810. When a person has playful and observant interactions with natural things, both regularities and
  811. irregularities will be noticed, and in trying to understand those events, the richness of the experience
  812. will suggest an expansive range of possibilities. Perception and experimentation lead to understandings that
  813. are independent of culture and tradition.
  814. </p>
  815. <p>
  816. But the mystique of science easily imposes itself, and distracts our attention from direct interactions with
  817. things. As we learn to operate lab instruments, we are taught the kinds of results that can be expected, and
  818. the concepts that will explain and predict the results of our operations. Science, as we learn about it in
  819. schools and the mass media, is mostly a set of catechisms.
  820. </p>
  821. <p>
  822. Our theories about organisms inform our experiments with cells or tissues that have been isolated from those
  823. organisms. The conditions for growing cells in dishes are thought of as "physiological," in relation to the
  824. solution's "physiological osmolarity," "physiological pH," nutrients, oxygenation, temperature, pressure,
  825. etc. But these concepts of what is physiological derive from the monolithic ideology of the doctrinaire, and
  826. often fraudulent, mainstream of biological science.
  827. </p>
  828. <p>
  829. The catechismic nature of science has led people to expect some "break-throughs" to occur in certain areas,
  830. and as authoritarian science has grown into "big science" managed by corporations and governments, those
  831. break-throughs are generally expected to be produced by the newest and most expensive developments of "high
  832. technology."
  833. </p>
  834. <p>
  835. But looking closely at the real events and processes in the sciences in the last couple of centuries, it
  836. turns out that useful advances have been produced mainly by breaking away from authoritarian doctrines, to
  837. return to common sense and relatively simple direct observations.
  838. </p>
  839. <p>
  840. Although people were cloning animals in the 1960s, it was still widely taught that it was impossible. The
  841. students of the professors who taught that it was impossible are now saying that it requires high technology
  842. and new research.
  843. </p>
  844. <p>
  845. For the last 100 years the most authoritative view in biology has been that there are no stem cells in
  846. adults, that brains, hearts, pancreases and oocytes are absolutely incapable of regeneration. But now,
  847. people seem to be finding stem cells wherever they look, but there is a mystique of high technology involved
  848. in finding and using them.
  849. </p>
  850. <p>
  851. Whether it's deliberate or not, the emphasis on stem cell technology has the function of directing attention
  852. away from traditional knowledge, the way allopathic medicine has de-emphasized the intrinsic ability of
  853. people to recover from disease.
  854. </p>
  855. <p>
  856. This resembles the way that the Mendel-Morgan gene doctrine was used to suppress the knowledge gained from
  857. centuries of experience of plant and animal breeders, and to belittle the discoveries of Luther Burbank,
  858. Paul Kammerer, Trofim Lysenko, and Barbara McClintock. The same type of biochemical process that caused the
  859. hereditary changes those researchers studied are involved in the differentiation and dedifferentiation of
  860. stem cells that regulate healing and regeneration.
  861. </p>
  862. <p>
  863. In the 1940s, even children discussed the biological discoveries of the 1920s and 1930s, the work in
  864. regeneration and adaptation, parthenogenesis, and immortalization. The ideas of J. Loeb, T. Boveri, A.
  865. Gurwitsch, J. Needham, C.M. Child, A. Carrel, et al., had become part of the general culture.
  866. </p>
  867. <p>
  868. But that real biology was killed by a consortium of industry and government that began a little before the
  869. second world war. In 1940, the government was supporting research in chemical and biological warfare, and
  870. with the Manhattan Project the role of government became so large that all of the major research
  871. universities were affected. Shortly after the war, many researchers from the Manhattan Project were
  872. redeployed into "molecular genetics," where the engineering attitude was applied to organisms.
  873. </p>
  874. <p>
  875. The simplistic genetic dogmas were compatible with the reductionist engineering approach to the organism.
  876. The role of the government assured that the universities would subscribe to the basic scientific agenda. The
  877. atmosphere of that time was described by Carl Lindegren as "The Cold War in Biology" (1966).
  878. </p>
  879. <p>
  880. The disappearance of the field concept in developmental biology was one of the strangest events in the
  881. history of science. It didn't just fade away, it was "disappeared," in a massive undertaking of social
  882. engineering. In its absence, stem cells will seem to be a profitable technological marvel, rather than a
  883. universal life function, with a central role in everything we are and everything we do and can become.
  884. </p>
  885. <p>
  886. Many people have tried to explain aging as a loss of cells, resulting from an intrinsic inability of any
  887. cell other than a germ cell to multiply more than a certain number of times. More than 40 years ago Leonard
  888. Hayflick popularized this doctrine in its most extreme form, saying that no cell can divide more than 50
  889. times unless it is converted into a cancer cell. He and his followers claimed that they had explained why
  890. organisms must age and die. At the moment the ovum is fertilized, the clock starts ticking for the
  891. essentially mortal somatic cells.
  892. </p>
  893. <p>
  894. In 1970, it was being seriously proposed that memory was produced by the death of brain cells, in a manner
  895. analogous to the holes punched in cards to enter data into computers. The cultural dogma made it impossible
  896. to consider that learning could be associated with the birth of new cells in the adult brain.
  897. </p>
  898. <p>
  899. With the announcement in 1997 of the cloning of the sheep Dolly from a somatic cell taken from a 6 year old
  900. sheep, there was renewed interest in the idea made famous by Alexis Carrel that all cells are potentially
  901. immortal, and in the possibility of preserving the vitality of human cells. Within a few months, Hayflick
  902. began reminding the public that "In the early 1960's we overthrew this dogma after finding that normal cells
  903. do have a finite replicative capacity." ("During the first half of this century it was believed that because
  904. cultured normal cells were immortal, aging must be caused by extra-cellular events.") The way Hayflick
  905. "overthrew" more than 35 years of work at the Rockefeller Institute was by growing one type of cell, a lung
  906. fibroblast, in culture dishes, and finding that the cultures deteriorated quickly.
  907. </p>
  908. <p>
  909. To draw global conclusions about an organism's development and aging from the degenerative processes seen in
  910. a single type of cell, grown in isolation from all normal stimuli, would have been treated as nothing but
  911. wild speculation, except that it occurred within a culture that needed it. No aspect of Hayflick's cell
  912. culture system could properly be called physiological.
  913. </p>
  914. <p>
  915. Other researchers, simply by changing a single factor, caused great increases in the longevity of the
  916. cultured cells. Simply using a lower, more natural oxygen concentration, the cells were able to undergo 20
  917. more divisions. Just by adding niacin, 30 more divisions; vitamin E, 70 more divisions. Excess oxygen is a
  918. poison requiring constant adaptation.
  919. </p>
  920. <p>
  921. Hayflick also published the observation that, while the cells kept in dishes at approximately body
  922. temperature deteriorated, cells kept frozen in liquid nitrogen didn't deteriorate, and he concluded that
  923. "time" wasn't the cause of aging. When I read his comments about the frozen cells, I wondered how anyone of
  924. normal intelligence could make such stupid statements. Since then, facts that came out because of the
  925. Freedom of Information Act, cause me to believe that a financial motive guided his thoughts about his
  926. cultured fibroblasts.
  927. </p>
  928. <p>
  929. Hayflick and his followers have been attacking the idea of anti-aging medicine as quackery. But he is
  930. closely involved with the Geron corporation, which proposes that genetic alterations relating to telomeres
  931. may be able to cure cancer and prevent aging. Their claims were reported by CNN as "Scientists discover
  932. cellular 'fountain of youth'."
  933. </p>
  934. <p>
  935. The "wear and tear" doctrine of aging that derived from the ideology of the gene was reinforced and renewed
  936. by Hayflick's cell culture observations, and it continued to rule the universities and popular culture.
  937. </p>
  938. <p>
  939. But detailed investigation of skin cell growth showed that cells in the lower layer of the skin divide at
  940. least 10,000 times in a normal lifetime, and similar processes occur in the lining of the intestine. The
  941. endometrium and other highly renewable tissues just as obviously violated Hayflick's limit. Transplantation
  942. experiments showed that pieces of mammary tissue or skin tissue could survive through ten normal lifetimes
  943. of experimental animals without suffering the effects of aging.
  944. </p>
  945. <p>
  946. Even the liver and adrenal gland are now known to be continuously renewed by "cell streaming," though at a
  947. slower rate than the skin, conjunctiva, and intestine. Neurogenesis in the brain is now not only widely
  948. accepted, it is even proposed as a mechanism to explain the therapeutic effects of antidepressants
  949. (Santarelli, et al., 2003).
  950. </p>
  951. <p>
  952. August Weismann's most influential doctrine said that "somatic cells are mortal, only the germline cells are
  953. immortal," but he based the doctrine on his mistaken belief that only the "germline" cells contained all the
  954. genes of the organism. In 1885, to "refute" Darwin's belief that acquired traits could be inherited, he
  955. promulgated an absolute "barrier" between "germline" and "soma," and invented facts to show that hereditary
  956. information can flow only from the germline to the somatic cells, and not the other direction. Shortly after
  957. DNA became popular in the 1950s as "the genetic material," Weismann's barrier was restated as the Central
  958. Dogma of molecular genetics, that information flows only from DNA to RNA to protein, and never the other
  959. direction.
  960. </p>
  961. <p>
  962. It was only in 2003, after the reality of cloning was widely recognized, that a few experimenters began to
  963. investigate the origin of "germline" cells in the ovary, and to discover that they derive from somatic cells
  964. (Johnson, et al., 2004). With this discovery, the ancient knowledge that a twig (<em>klon</em>, in Greek)
  965. cut from a tree could grow into a whole tree, bearing fruit and viable seeds, was readmitted to general
  966. biology, and the Weismann barrier was seen to be an illusion.
  967. </p>
  968. <p>
  969. Millions of people have "explained" female reproductive aging as the consequence of the ovary "running out
  970. of eggs." Innumerable publications purported to show the exact ways in which that process occurs, following
  971. the Weismann doctrine. But now that it is clear that adult ovaries can give birth to new oocytes, a new
  972. explanation for female reproductive aging is needed. It is likely that the same factors that cause female
  973. reproductive aging also cause aging of other systems and organs and tissues, and that those factors are
  974. extrinsic to the cells themselves, as Alexis Carrel and others demonstrated long ago. This is a way of
  975. saying that all cells are potential stem cells. The "niche" in which new cells are born in the streaming
  976. organism, and the processes by which damaged cells are removed, are physiological issues that can be
  977. illuminated by the idea of a morphogenetic field.
  978. </p>
  979. <p>
  980. When the post-war genetic engineers took over biological research, the idea of a biophysical field was
  981. totally abandoned, but after about 15 years, it became necessary to think of problems beyond those existing
  982. within a single bacterium, namely, the problem of how an ovum becomes and embryo. Francis Crick, of DNA
  983. fame, who was educated as a physicist, revived (without a meaningful historical context) the idea of a
  984. diffusion gradient as a simple integrating factor that wouldn't be too offensive to the reductionists. But
  985. for events far beyond the scale of the egg's internal structure, for example to explain how a nerve axon can
  986. travel a very long distance to innervate exactly the right kind of cell, the diffusion of molecules loses
  987. its simplicity and plausibility. (Early in the history of experimental embryology, it was observed that
  988. electrical fields affect the direction of growth of nerve fibers.)
  989. </p>
  990. <p>
  991. C. M. Child saw a gradient of metabolic activity as an essential component of the morphogenetic field. This
  992. kind of gradient doesn't deny the existence of diffusion gradients, or other physical components of a field.
  993. Electrical and osmotic (and electro-osmotic) events are generated by metabolism, and affect other factors,
  994. including pH, oxidation and reduction, cell motility and cell shape, ionic selectivity and other types of
  995. cellular selectivity and specificity. Gradients of DNA methylation exist, and affect the expression of
  996. inherited information.
  997. </p>
  998. <p>
  999. Methylation decreases the expression of particular genes, and during the differention of cells in the
  1000. development of an embryo, genes are methylated and demethylated as the cell adapts to produce the proteins
  1001. that are involved in the structure and function of a particular tissue. Methylation (which increases a
  1002. molecule's affinity for fats) is a widespread process in cells, and for example regulates cellular
  1003. excitability. It is affected by diet and a variety of stresses.
  1004. </p>
  1005. <p>
  1006. DNA methylation patterns are normally fairly stable, and can help to account for the transgenerational
  1007. transmission of acquired adaptations, and for neonatal imprinting that can last a lifetime. But with injury,
  1008. stress, and aging, the methylation patterns of differentiated tissues can be changed, contributing to the
  1009. development of tumors, or to the loss of cellular functions. Even learning can change the methylation of
  1010. specific genes. During <em>in vitro</em> culture, the enzymes of gene methylation are known to be increased,
  1011. relative to their normal activity (Wang, et al., 2005).
  1012. </p>
  1013. <p>
  1014. The phenomenon of "gene" methylation in response to environmental and metabolic conditions may eventually
  1015. lead to the extinction of the doctrine that "cells are controlled by their genes."
  1016. </p>
  1017. <p>
  1018. During successful adaptation to stress, cells make adjustments to their metabolic systems (for example with
  1019. a holistic change of the degree of phosphorylation, which increases molecules' affinity for water), and
  1020. their metabolic processes can contribute to changes in their state of differentiation. Some changes may lead
  1021. to successful adaptation (for example by producing biogenic stimulators that stimulate cell functioning and
  1022. regeneration), others to failed adaptation. Even the decomposition of cells can release substances that
  1023. contribute to the adaptation of surrounding cells, for example when sphingosines stimulate the production of
  1024. stem cells.
  1025. </p>
  1026. <p>
  1027. DNA methylation is just one relatively stable event that occurs in relation to a metabolic field.
  1028. Modifications of histones (regulatory proteins in chromosomes, which are acetylated as well as methylated)
  1029. and structural-contractile filaments also contribute to the differentiation of cells, but the pattern of DNA
  1030. methylation seems to guide the methylation of histones and the structure of the chromosomes (Nan, et al.,
  1031. 1998).
  1032. </p>
  1033. <p>
  1034. Steroids and phospholipids, neurotransmitters and endorphins, ATP, GTP, other phosphates, retinoids, NO and
  1035. CO2--many materials and processes participate in the coherence of the living state, the living substance.
  1036. Carbon dioxide, for example, by binding to lysine amino groups in the histones, will influence their
  1037. methylation. Carbon dioxide is likely to affect other amino groups in the chromosomes.
  1038. </p>
  1039. <p>
  1040. The number and arrangement of mitochondria is an important factor in producing and maintaining the metabolic
  1041. gradients. Things that decrease mitochondrial energy production--nitric oxide, histamine, cytokines,
  1042. cortisol--increase DNA methylation. Decreased gene expression is associated with reduced respiratory energy.
  1043. It seems reasonable to guess that increased gene expression would demand increased availability of energy.
  1044. </p>
  1045. <p>
  1046. As an ovum differentiates into an organism, cells become progressively more specialized, inhibiting the
  1047. expression of many genes. Less energy is needed by stably functioning cells, than by actively adapting
  1048. cells. A.I. Zotin described the process of maturing and differentiating as a decrease of entropy, an
  1049. increase of order accompanying a decreased energy expenditure. The entropic egg develops into a less
  1050. entropic embryo with a great expenditure of energy.
  1051. </p>
  1052. <p>
  1053. The partially differentiated stem cell doesn't go through all the stages of development, but it does expend
  1054. energy intensely as it matures.
  1055. </p>
  1056. <p>
  1057. The restoration of energy is one requirement for the activation of regeneration. When a hormone such as
  1058. noradrenaline or insulin causes a stem cell to differentiate in vitro, it causes new mitochondria to form.
  1059. This is somewhat analogous to the insertion of mitochondria into the ripening oocyte, by the nurse cells
  1060. that surround it. The conditionally decreased entropy of maturation is reversed, and when sufficient
  1061. respiratory energy is available, the renewed and refreshed cell will be able to renew an appropriate degree
  1062. of differentiation.
  1063. </p>
  1064. <p>
  1065. When simple organisms, such as bacteria, fungi, or protozoa are stressed, for example by the absence of
  1066. nutrients or the presence of toxins, they slow their metabolism, and suppress the expression of genes,
  1067. increasing the methylation of DNA, to form resistant and quiescent spores. Our differentiated state doesn't
  1068. go to the metabolic extreme seen in sporulation, but it's useful to look at maturity and aging in this
  1069. context, because it suggests that the wrong kind of stress decreases the ability of the organism to adapt,
  1070. by processes resembling those in the spore-forming organisms.
  1071. </p>
  1072. <p>
  1073. Charles Vacanti, who has grown cartilage from cells taken from 100 year old human cartilage, believes our
  1074. tissues contain "spore cells," very small cells with slow metabolism and extreme resistance to heat, cold,
  1075. and starvation.
  1076. </p>
  1077. <p>
  1078. If the slowed metabolism of aging, like that of sporulating cells, is produced by a certain kind of stress
  1079. that lowers cellular energy and functions, it might be useful to think of the other stages of the stress
  1080. reaction in relation to the production of stem cells. Selye divided stress into a first stage of shock,
  1081. followed by a prolonged adaptation, which could sometimes end in exhaustion. If the maturity of
  1082. differentiated functioning is equivalent to the adaptation phase, and cellular decline and disintegration is
  1083. the exhaustion phase, then the shock-like reaction would correspond to the birth of new stem cells.
  1084. </p>
  1085. <p>
  1086. Selye described estrogen's effects as equivalent to the shock-phase of stress. Estrogen's basic action is to
  1087. make oxygen unavailable, lowering the oxygen tension of the tissues, locally and temporarily. Like nitric
  1088. oxide, which is produced by estrogenic stimulation, estrogen interferes with energy production, so if its
  1089. stimulation is prolonged, cells are damaged or killed, rather than being stimulated to regenerate.
  1090. </p>
  1091. <p>
  1092. Extrinsic factors elicit renewal, the way stress can elicit adaptation. While aging cells can't use the
  1093. oxygen that is present, a scarcity of oxygen can serve as a stimulus to maximize the respiratory systems.
  1094. Brief oxygen deprivation excites a cell, causes it to swell, and to begin to divide.
  1095. </p>
  1096. <p>
  1097. Oxygen deprivation, as in the normally hypoxic bone marrow, stimulates the formation of stem cells, as well
  1098. as the biogenesis of mitochondria. As the newly formed cells, with abundant mitochondria, get adequate
  1099. oxygen, they begin differentiation.
  1100. </p>
  1101. <p>
  1102. Form, based on cellular differentiation, follows function--a vein transplanted into an artery develops
  1103. anatomically into an artery, a colon attached directly to the anus becomes a new rectum with its appropriate
  1104. innervation, a broken bone restructures to form a normal bone. If the bladder is forced to function more
  1105. than normal, by artificially keeping it filled, its thin wall of smooth muscle develops into a thick wall of
  1106. striated muscle that rhythmically contracts, like the heart. If a tadpole is given a vegetarian diet, the
  1107. absorptive surface of its digestive system will develop to be twice the size of those that are fed meat.
  1108. Pressure, stretching, and pulsation are among the signals that guide cells' differentiation.
  1109. </p>
  1110. <p>
  1111. Very early in the study of embryology it was noticed that the presence of one tissue sometimes induced the
  1112. differentiation of another kind, and also that there were factors in embryonic tissues that would stimulate
  1113. cell division generally, and others that could inhibit the growth of a particular tissue type. Diffusable
  1114. substances and light were among the factors identified as growth regulators.
  1115. </p>
  1116. <p>
  1117. Extracts of particular tissues were found to suppress the multiplication of cells in that type of tissue, in
  1118. adult animals as well as in embryos. In the 1960s, the tissue-specific inhibitors were called chalones.
  1119. </p>
  1120. <p>
  1121. The brain's development is governed by the presence in the organism of the body part to which it
  1122. corresponds, such as the eyes or legs. The number of cells in a particular part of the nervous system is
  1123. governed by the quantity of nervous input, sensory or motor, that it receives. An enriched environment
  1124. causes a bigger brain to grow. Sensory nerve stimulation of a particular region of the brain causes nerve
  1125. cells to migrate to that area (a process called neurobiotaxis; deBeers, 1927), but nerve stimulation also
  1126. causes mitochondria to accumulate in stimulated areas. Nerve activity has a trophic, sustaining influence on
  1127. other organs, as well as on the brain. Nerve stimulation, like mechanical pressure or stretching, is an
  1128. important signal for cellular differentiation.
  1129. </p>
  1130. <p>
  1131. When stem cells or progenitor cells are called on to replace cells in an organ, they are said to be
  1132. "recruited" by that organ, or to "home" to that organ, if they are coming from elsewhere. Traditionally, the
  1133. bone marrow has been considered to be the source of circulating stem cells, but it now appears that a
  1134. variety of other less differentiated cells can be recruited when needed. Cells from the blood can repair the
  1135. endothelium of blood vessels, and endothelial cells can become mesenchymal cells, in the heart, for example.
  1136. </p>
  1137. <p>
  1138. The standard doctrine about cancer is that a tumor derives from a single mutant cell, but it has been known
  1139. for a long time that different types of cell, such as phagocytes and mast cells, usually reside in tumors,
  1140. and it is now becoming clear that tumors recruit cells, including apparently normal cells, from other parts
  1141. of the same organ. For example, a brain tumor of glial cells, a glioma, recruits glial cells from
  1142. surrounding areas of the brain, in a process that's analogous to the embryological movement of nerve cells
  1143. to a center of excitation. Each tumor, in a sense, seems to be a center of excitation, and its fate seems to
  1144. depend on the nature of the cells that respond to its signals.
  1145. </p>
  1146. <p>
  1147. To accommodate some of the newer facts about tumors, the cancer establishment has begun speaking of "the
  1148. cancer stem cell" as the real villain, the origin of the tumor, while the bulk of the tumor is seen to be
  1149. made up of defective cells that have a short life-span. But if we recognize that tumors are recruiting cells
  1150. from beyond their boundaries, this process would account for the growth and survival of a tumor even while
  1151. most of its cells are inert and dying, without invoking the invisible cancer stem cell. And this view, that
  1152. it is the field which is defective rather than the cell, is consistent with the evidence which has been
  1153. accumulating for 35 years that tumor cells, given the right environment, can differentiate into healthy
  1154. cells. (Hendrix, et al., 2007)
  1155. </p>
  1156. <p>
  1157. Simply stretching an organ (Woo, et al., 2007) is stimulus enough to cause it to recruit cells from the
  1158. bloodstream, and will probably stimulate multiplication in its local resident cells, too. Every "cancer
  1159. field" probably begins as a healing process, and generally the healing and regeneration are at least
  1160. partially successful.
  1161. </p>
  1162. <p>
  1163. When an organ--the brain, heart, liver, or a blood vessel--is inflamed or suffering from an insufficient
  1164. blood supply, stem cells introduced into the blood will migrate specifically to that organ.
  1165. </p>
  1166. <p>
  1167. Organ specific materials (chalones) are known to circulate in the blood, inhibiting cell division in cells
  1168. typical to that organ, but it also seems that organ specific materials are secreted by a damaged organ, that
  1169. help to prepare stem cells for their migration into that organ. When undifferentiated cells are cultured
  1170. with serum from a person with liver failure, they begin to differentiate into liver cells.
  1171. </p>
  1172. <p>
  1173. It is still common to speak of each organ as having a "clonal origin" in the differentiating embryo, as a
  1174. simple expansion of a certain embryonic anlage. The implication of this way of thinking is that
  1175. differentiation is <em>determination</em> in an irreversible sense. This is another case of medical ideas
  1176. being based on images of fixed histological material. Normal cells, including nerve and muscle cells, can
  1177. change type, with connective tissue cells becoming nerve cells, nerve cells becoming muscle and fiber cells,
  1178. fat, fiber, and muscle cells redifferentiating, for example.
  1179. </p>
  1180. <p>
  1181. Cell movements in solid tissues aren't limited to the short distances between capillaries and the tissues
  1182. nourished by those capillaries, rather, cells can migrate much greater distances, without entering the
  1183. bloodstream. The speed of a single cell moving by ameboid motion can be measured by watching cells on a
  1184. glass slide as they move toward food, or by watching cells of the slime mold Dictyostelium when they are
  1185. aggregating, or by watching the pigment cells in and around moles or melanomas, under the influence of
  1186. hormones. At body temperature, a single cell can crawl about an inch per day. Waves or spots of brown
  1187. pigment can be seen migrating through the skin away from a mole, preceding the disintegration of the mole
  1188. under the influence of progesterone or DHEA. Under ordinary conditions, pigment cells can sometimes be seen
  1189. migrating into depigmented areas of skin, during the recovery of an area affected by vitiligo. These
  1190. organized movements of masses of cells happen to be easy to see, but there is evidence that other types of
  1191. cell can reconstruct tissues by their ameboid movements, when circumstances are right. Tumors or tissue
  1192. abnormalities can appear or disappear with a suddenness that seems impossible to people who have studied
  1193. only fixed tissue preparations.
  1194. </p>
  1195. <p>
  1196. Stimulation is anabolic, building tissue, when the organism is adapting to the stimulation. Unused
  1197. structures in cells and tissues are always being recycled by metabolic processes. When tissues are injured
  1198. and become unable to function, some of their substances stimulate the growth of replacement cells.
  1199. </p>
  1200. <p>
  1201. Some types of injury or irritation can activate regenerative processes. A dermatology journal described the
  1202. case of an old man who had been bald for many years who fell head-first into his fireplace. As his burned
  1203. scalp healed, new hair grew. In the U.S., experimenters (Ito, et al., 2007) have found that injuring the
  1204. skin of mice stimulates the formation of stem cells that are able to become hair follicle cells, supporting
  1205. the regeneration of cells that had been absent. A brief exposure to estrogen, and other stress related
  1206. signals (nitric oxide, endorphin, prostaglandins) can initiate stem cell proliferation.
  1207. </p>
  1208. <p>
  1209. In the years after the first world war, Vladimir Filatov, who developed techniques of reconstructive
  1210. surgery, including corneal transplants, found that cold storage of tissues (for example, corneas from
  1211. cadavers) caused them to function better than fresh tissues, and he found that these stressed tissues would
  1212. often spread a healing influence out into the surrounding tissues. Extracts of stressed tissues produced
  1213. similar effects.
  1214. </p>
  1215. <p>
  1216. L.V. Polezhaev began studying the regenerative capacities of mammals in the late 1940s, and his work showed
  1217. that processes similar to embryonic induction are involved in the organism's responses to damaged tissues.
  1218. For example, when a piece of killed muscle tissue is enclosed in a capsule ("diffusion chamber") that
  1219. permits molecules, but no cells, to diffuse through it, and implanted subcutaneously, it had no inductive
  1220. effect on surrounding cells. But when the pores of the capsule allowed cells to enter, skeletal muscle
  1221. formed where the dead tissue had been, and tissue resembling heart muscle formed outside the capsule.
  1222. Phagocytosis had been essential for the induction to occur.
  1223. </p>
  1224. <p>
  1225. Macrophages are ordinarily thought of as "antigen-presenting cells" that help to activate the specific
  1226. immune responses. But apparently phagocytosis is involved in the replacement of damaged tissues, by
  1227. recruiting or inducing the differentiation of replacement cells. The phagocytosis function isn't limited to
  1228. the blood cells commonly called phagocytes; even nerve cells can ingest particles and fragments of damaged
  1229. tissues.
  1230. </p>
  1231. <p>
  1232. Many factors regulate the process of phagocytosis. Stress and lipid peroxidation decrease phagocytosis
  1233. (Izg"t-Uysal, et al., 2004), and also damage mitochondria and inhibit cell renewal.
  1234. </p>
  1235. <p>
  1236. Unsaturated fatty acids inhibit phagocytosis (Guimaraes, et al., 1991, 1992; Costa Rosa, et al., 1996;
  1237. Virella, et al., 1989; Akamatsu, et al., 1990), and suppress mitochondrial function (Gomes, et al., 2006).
  1238. Dietary restriction activates phagocytosis (Moriguchi, et al., 1989), suggesting that normal diets contain
  1239. suppressive materials.
  1240. </p>
  1241. <p>
  1242. Subnormal temperatures cause a shift from phagocytosis to inflammation. Light, especially the red light
  1243. which penetrates easily into tissues, activates the formation of new cells as well as their differentiation.
  1244. It affects energy production, increasing the formation of mitochondria, and the activity of the DNA
  1245. methyltransferase enzymes. Red light accelerates wound healing, and improves the quality of the scar,
  1246. reducing the amount of fibrosis. The daily cycling between darkness and light is probably an important
  1247. factor in regulating the birth and differentiation of cells.
  1248. </p>
  1249. <p>
  1250. Darkness suppresses mitochondrial function, and light activates it. Prolonged darkness increases cortisol,
  1251. and cortisol (which makes cells more susceptible to excitotoxic death) inhibits stem cell proliferation (Li,
  1252. et al., 2006; Liu, et al., 2003). Neurogenesis is suppressed by stress, and increased by spontaneous
  1253. activity, and has a circadian rhythm. Aging and depression both involve a diminished ability to rhythmically
  1254. lower the production of cortisol. Cell renewal requires a rhythmic decrease in the exposure to cortisol..
  1255. </p>
  1256. <p>
  1257. In the spring, with increased day length, the brains of song-birds grow, with an increased proliferation of
  1258. cells in the part of the brain involved in singing. The production of progesterone increases in most animals
  1259. in the spring, and it is the main hormone responsible for the birds' brain growth.
  1260. </p>
  1261. <p>
  1262. Progesterone and its metabolites protect brain cells against injury, and improve the brain's ability to
  1263. recover after traumatic injury (Brinton and Wang, 2006). In the 1960s, Marion Diamond's group showed that
  1264. environmental enrichment, or progesterone, caused brains to grow larger, and that these changes were passed
  1265. on to descendants in a cumulative, increasing way. This suggests that the factors that promote neurogenesis
  1266. also cause changes in the apparatus of reproduction and inheritance, that support the development of the
  1267. brain--probably including the methylation system, which is involved in regulating genes, and also mood and
  1268. behavior.
  1269. </p>
  1270. <p>
  1271. Women's monthly cycles, in which a brief estrogen dominance is followed by sustained exposure to
  1272. progesterone, are probably an important factor in the renewal of the cells of the brain and other organs, as
  1273. well as those of the reproductive organs. The daily rhythms of hormones and metabolism are known to be
  1274. involved in the regulation of cell renewal.
  1275. </p>
  1276. <p>
  1277. Environmental enrichment, learning, high altitude, and thyroid hormone promote the formation of new
  1278. mitochondria, and stimulate stem cell proliferation. At least in some laboratories, 20% oxygen,
  1279. approximately the amount as in the atmosphere, suppresses the proliferation of stem cells (He, et al.,
  1280. 2007). This was the unphysiologically high concentration of oxygen used in Hayflick's cell cultures. At high
  1281. altitudes, where tissues are exposed to less oxygen, and more carbon dioxide, there is a lower incidence of
  1282. all the degenerative diseases, including cancer, heart disease, and dementia. Improved cellular energy
  1283. production and more active renewal of cells would probably account for those differences.
  1284. </p>
  1285. <p>
  1286. For Crick, the idea of a diffusion gradient to explain embryonic development was simply an extension of his
  1287. reductionist orientation, in which diffusing molecules induced or inhibited bacterial genes, and in which
  1288. genes controlled cells. For people with that orientation, the adaptive mutations described by Carl
  1289. Lindegren, and later by John Cairns, or even the stress-induced variability described by Lysenko, Strong,
  1290. and McClintock, were heretical. Polezhaev's demonstration that cells could do something that molecular
  1291. diffusion didn't do, threatened to take biology away from the reductionists. If the organism's adaptation to
  1292. the environment involves changing its own genes, Crick's paradigm fails.
  1293. </p>
  1294. <p>
  1295. Crick's Central Dogma, derived from the ideology that produced Weismann's Barrier, has been invoked by
  1296. generations of professors who wanted to deny the possibility of adaptive tissue renewal and regeneration.
  1297. Without the dogma, new ideas about aging and disease will be needed. If somatic cells can adjust their
  1298. genes, and if they can also differentiate into new eggs and sperms, new ideas about inheritance of acquired
  1299. traits will be needed.
  1300. </p>
  1301. <p>
  1302. The replacement of injured cells means that mutations need not accumulate. Cell renewal with elimination of
  1303. mutant cells has been observed in sun-damaged skin simply by stopping the damage, and mitochondria with
  1304. damaged DNA can be replaced by healthy mitochondria simply by doing the right kind of exercise.
  1305. </p>
  1306. <p>
  1307. The regulation of cell renewal probably involves all of the processes of life, but there are a few simple,
  1308. interacting factors that suppress renewal. The accumulation of polyunsaturated fats, interacting with a high
  1309. concentration of oxygen, damages mitochondria, and causes a chronic excessive exposure to cortisol. With
  1310. mitochondrial damage, cells are unable to produce the progesterone needed to oppose cortisol and to protect
  1311. cells.
  1312. </p>
  1313. <p>
  1314. Choosing the right foods, the right atmosphere, the right mental and physical activities, and finding the
  1315. optimal rhythms of light, darkness, and activity, can begin to alter the streaming renewal of cells in all
  1316. the organs. Designing a more perfect environment is going to be much simpler than the schemes of the genetic
  1317. engineers.
  1318. </p>
  1319. <p><h3>REFERENCES</h3></p>
  1320. <p>
  1321. Growth 43, 58-61, 1979. <strong>The effect of progesterone on brain and body growth of chick
  1322. embryos.</strong> G. Ahmad and S. Zamenhof. [This showed that progesterone, added during the time of
  1323. active neuronal proliferation, increased the chicks' brain weight, while the stress hormone, corticosterone,
  1324. reduced the weight.]
  1325. </p>
  1326. <p>
  1327. J Invest Dermatol. 1990 Sep;95(3):271-4. <strong>Suppressive effects of linoleic acid on neutrophil oxygen
  1328. metabolism and phagocytosis.</strong> Akamatsu H, Komura J, Miyachi Y, Asada Y, Niwa Y.
  1329. </p>
  1330. <p>
  1331. Curr Alzheimer Res. 2006 Feb;3(1):11-7. <strong>Preclinical analyses of the therapeutic potential of
  1332. allopregnanolone to promote neurogenesis in vitro and in vivo in transgenic mouse model of Alzheimer's
  1333. disease.</strong> Brinton RD, Wang JM. "Herein, we present data to support a preclinical proof of
  1334. concept for the therapeutic potential of allopregnanolone to promote neurogenesis. Our recent work has
  1335. demonstrated that the neuroactive progesterone metabolite, allopregnanolone
  1336. (3alpha-hydroxy-5alpha-pregnan-20-one), (APalpha) induced, in a dose dependent manner, a significant
  1337. increase in proliferation of neuroprogenitor cells (NPCs) derived from the rat hippocampus and human neural
  1338. stem cells (hNSM) derived from the cerebral cortex [1]." "The in vitro and in vivo neurogenic properties of
  1339. APalpha coupled with a low molecular weight, easy penetration of the blood brain barrier and lack of
  1340. toxicity, are key elements required for developing APalpha as a neurogenic / regenerative therapeutic for
  1341. restoration of neurons in victims of Alzheimer's disease."
  1342. </p>
  1343. <p>
  1344. Arch Biochem Biophys. 1996 Jan 1;325(1):107-12.<strong>
  1345. Thyromimetic action of the peroxisome proliferators clofibrate, perfluorooctanoic acid, and
  1346. acetylsalicylic acid includes changes in mRNA levels for certain genes</strong>
  1347. <strong>
  1348. involved in mitochondrial biogenesis.</strong> Cai Y, Nelson BD, Li R, Luciakova K, dePierre JW.
  1349. </p>
  1350. <p>
  1351. Biochem Mol Biol Int. 1996 Nov;40(4):833-42. <strong>The effect of N-3 PUFA rich diet upon macrophage and
  1352. lymphocyte metabolism and function.</strong> Costa Rosa LF, Safi DA, Guimar"es AR.
  1353. </p>
  1354. <p>
  1355. G. R. de Beer, <strong><em>An Introducton to Experimental Embryology,</em></strong>
  1356. Oxford, 1926.
  1357. </p>
  1358. <p>
  1359. Biol. Rev. 1927;2:137-197, <strong>The mechanics of verterate development. </strong>
  1360. de Beer GR.
  1361. </p>
  1362. <p>
  1363. Vrach delp. 1937, 20: 803-820. <strong>Summary of 20 years' achievements in ophthalmology.</strong>
  1364. Filatov VP.
  1365. </p>
  1366. <p>
  1367. Vestnik oftal. 1938, 12: 107-159.<strong>
  1368. Tissue transplantation in intra-ocular diseases.</strong> Filatov VP.
  1369. </p>
  1370. <p>
  1371. Med zhur 1937, 9: 847-853.<strong>
  1372. Intramuscular injections of cod liver oil in therapy of pigmented retinitis.</strong> Filatov VP,
  1373. Verbitska E A.
  1374. </p>
  1375. <p>
  1376. Am Rev Soviet Med. 1946, 3: 388-395.<strong>
  1377. The treatment of retinitis pigmentosa with intramuscular injection of cod liver oil.</strong> Filatov
  1378. VP, Verbitska EA.
  1379. </p>
  1380. <p>
  1381. Am Rev Soviet Med 1946, 3: 395-397. <strong>Retinitis pigmentosa.</strong> Filatov VP.
  1382. </p>
  1383. <p>
  1384. Am Rev Soviet Med 1946, 3: 397-398.<strong>
  1385. The implantation of preserved placenta in retinitis pigmentosa.</strong> Filatov VP Verbitska EA.
  1386. </p>
  1387. <p>
  1388. Hippocampus. 2006;16(3):225-32.<strong>
  1389. Gonadal hormone modulation of hippocampal neurogenesis in the adult.
  1390. </strong>Galea LA, Spritzer MD, Barker JM, Pawluski JL. <strong>
  1391. Estradiol, the most potent estrogen, initially enhances and subsequently suppresses cell proliferation
  1392. in the dentate gryus of adult female rodents.</strong>
  1393. </p>
  1394. <p>
  1395. Glia. 1999 Feb 1;25(3):247-55. <strong>Cerebellar astrocytes treated by thyroid hormone modulate neuronal
  1396. proliferation.</strong> Gomes FC, Maia CG, de Menezes JR, Neto VM. "Thyroid hormones are important for
  1397. neurogenesis and gliogenesis during brain development. We have previously demonstrated that triiodothyronine
  1398. (T3) treatment induced proliferation in primary culture astrocytes derived from the cerebellum of neonatal
  1399. rats." "Interestingly, the cerebellar neuronal population increased by 60-80% in T3CM."
  1400. </p>
  1401. <p>
  1402. Biochem Int. 1992 Jun;27(1):9-16. <strong>Metabolic and functional changes in macrophages of rats fed
  1403. polyunsaturated or saturated fatty acid rich-diets during ageing.
  1404. </strong>Guimar"es AR, Costa Rosa LF, Safi DA, Curi R.
  1405. </p>
  1406. <p>
  1407. Biochem Int. 1991 Feb;23(3):533-43. <strong>Effect of polyunsaturated (PUFA n-6) and saturated fatty
  1408. acids-rich diets on macrophage metabolism and function.</strong>
  1409. Guimar"es AR, Costa Rosa LF, Sitnik RH, Curi R.
  1410. </p>
  1411. <p>
  1412. Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2007 Apr;15(2):433-6. <strong>[Effect of hypoxia on mesenchymal stem
  1413. cells - review.]</strong>
  1414. [Article in Chinese] He MC, Li J, Zhao CH.
  1415. </p>
  1416. <p>
  1417. Nat Rev Cancer. 2007 Apr;7(4):246-55. <strong>Reprogramming metastatic tumour cells with embryonic
  1418. microenvironments.</strong> Hendrix MJ, Seftor EA, Seftor RE, Kasemeier-Kulesa J, Kulesa PM, Postovit
  1419. LM. "Aggressive tumour cells share many characteristics with embryonic progenitors, contributing to the
  1420. conundrum of tumour cell plasticity." "This Review will summarize the embryonic models used to reverse the
  1421. metastatic melanoma phenotype, and highlight the prominent signalling pathways that have emerged as
  1422. noteworthy targets for future consideration."
  1423. </p>
  1424. <p>
  1425. FEBS Lett. 1973 May 15;32(1):1-8.<strong>
  1426. Chalones. Specific endogenous mitotic inhibitors.</strong> Houck JC, Hennings H.
  1427. </p>
  1428. <p>
  1429. Med Hypotheses. 2005;64(6):1138-43. <strong>Melatonin seems to be a mediator that transfers the
  1430. environmental stimuli to oocytes for inheritance of adaptive changes through epigenetic inheritance
  1431. system.</strong> Irmak MK, Topal T, Oter S.
  1432. </p>
  1433. <p>
  1434. Nature. 2007 May 17;447(7142):316-20. <strong>Wnt-dependent de novo hair follicle regeneration in adult
  1435. mouse skin after wounding.
  1436. </strong>
  1437. Ito M, Yang Z, Andl T, Cui C, Kim N, Millar SE, Cotsarelis G.
  1438. </p>
  1439. <p>
  1440. Cell Biol Int. 2004;28(7):517-21. <strong>Effect of stress-induced lipid peroxidation on functions of rat
  1441. peritoneal macrophages.</strong> Izg"t-Uysal VN, Tan R, B"lb"l M, Derin N.
  1442. </p>
  1443. <p>
  1444. J Cereb Blood Flow Metab. 2007 Mar 28;<strong>
  1445. Regeneration and plasticity in the brain and spinal cord.</strong> Johansson BB.
  1446. </p>
  1447. <p>
  1448. Nature, 428, 145 - 150, (2004). Johnson, J., Canning, J., Kaneko, T., Pru, J.K. &amp; Tilly, J.L.
  1449. </p>
  1450. <p>
  1451. Annals of Ophthalmology No. 1, 2005, p. 54, <strong>Life devoted to fight against blindness</strong> (on the
  1452. 130th birthday anniversary of V. P. Filatov) Knopov M. Sh., Klyasov A. V.
  1453. </p>
  1454. <p>
  1455. R. Levi-Montalcini, <strong>"Neuronal regeneration in vitro," </strong>
  1456. pages 54-65 in Windle,<em> Regeneration in the Central Nervous System,</em>
  1457. C. C. Thomas, 1955.
  1458. </p>
  1459. <p>
  1460. Neurobiol Aging. 2006 Nov;27(11):1705-14. Epub 2005 Nov 4.<strong>
  1461. Salivary cortisol and memory function in human aging.</strong> Li G, Cherrier MM, Tsuang DW, Petrie EC,
  1462. Colasurdo EA, Craft S, Schellenberg GD, Peskind ER, Raskind MA, Wilkinson CW.
  1463. </p>
  1464. <p>
  1465. Med Hypotheses. 2007 Mar 27; [Epub ahead of print] <strong>Effects of hypoxia on proliferation and
  1466. differentiation of myoblasts.</strong> Li X, Zhu L, Chen X, Fan M.
  1467. </p>
  1468. <p>
  1469. Exp Neurol. 2003 Nov;184(1):196-213. <strong>Suppression of hippocampal neurogenesis is associated with
  1470. developmental stage, number of perinatal seizure episodes, and glucocorticosteroid level.</strong> Liu
  1471. H, Kaur J, Dashtipour K, Kinyamu R, Ribak CE, Friedman LK.
  1472. </p>
  1473. <p>
  1474. J Nutr Sci Vitaminol (Tokyo). 1989 Feb;35(1):49-59.<strong>
  1475. Effects of dietary restriction on cellular immunity in rats.</strong> Moriguchi S, Toba M, Kishino Y.
  1476. </p>
  1477. <p>
  1478. Nature. 1998 May 28;393(6683):386-9. <strong>Transcriptional repression by the methyl-CpG-binding protein
  1479. MeCP2 involves a histone deacetylase complex.</strong> Nan X, Ng HH, Johnson CA, Laherty CD, Turner BM,
  1480. Eisenman RN, Bird A.
  1481. </p>
  1482. <p>
  1483. L. V. Polezhaev and E. N. Karnaukhova, <strong>"Stimulation of physiologic regeneration of nervous tissue of
  1484. the cerebral cortex and its significance for biogenic therapy of neuro-mental diseases," pages 86-116 in
  1485. </strong>
  1486. <em>Sbornik: Klinicheskie eksperimentalnye osnovy biogennoi terapii psikhozov</em>,<strong> </strong>
  1487. 1962.
  1488. </p>
  1489. <p>
  1490. Doklady AN SSSR 150, 430-433, 1963., <strong>"Stimulation of nerve cell reproduction of cerebral cortex in
  1491. mammals,"</strong> L. V. Polezhaev and E. N. Karnaukhove
  1492. </p>
  1493. <p>
  1494. L. V. Polezhaev, <strong><em>Loss and Restoration of Regenerative Capacity in Tissues and Organs of
  1495. Animals,</em></strong> page 219, 1972.
  1496. </p>
  1497. <p>
  1498. J Hirnforsch 1991;32(5):659-664. <strong>Normalization of protein synthesis and the structure of brain
  1499. dystrophic neurons after the action of hypoxia, 10% NaCl and organ-specific RNA.</strong> Polezhaev LV,
  1500. Cherkasova LV, Vitvitsky VN, Timonin AV <strong>"Transplantation of embryonic nervous tissue (ENT) in one of
  1501. the hemispheres normalizes all the above abnormalities observed in some neurologic and mental diseases
  1502. in humans."</strong>
  1503. <strong>
  1504. "At the beginning 10% NaCl increased the destruction of brain cortical neurons and then stimulated
  1505. protein synthesis in them.</strong> RNA injections stimulated the synthesis in cortical neurons and
  1506. normalized their structure. Thus, we propose a safe and simple method for normalization of dystrophic
  1507. neurons which can be used after certain improvement for curing neurodegenerative and neuropsychic diseases
  1508. in humans."
  1509. </p>
  1510. <p>
  1511. Science. 2003 Aug 8;301(5634):757. <strong>Requirement of hippocampal neurogenesis for the behavioral
  1512. effects of antidepressants.</strong> Santarelli L, Saxe M, Gross C, Surget A, Battaglia F, Dulawa S,
  1513. Weisstaub N, Lee J, Duman R, Arancio O, Belzung C, Hen R.
  1514. </p>
  1515. <p>
  1516. Chin J Traumatol. 2002 Aug;5(4):246-9. <strong>Experimental study on He-Ne laser irradiation to inhibit scar
  1517. fibroblast growth in culture.</strong>
  1518. Shu B, Wu Z, Hao L, Zeng D, Feng G, Lin Y.
  1519. </p>
  1520. <p>
  1521. J Cell Biochem 2001; 80:455-60.<strong>
  1522. Identification and initial characterization of spore-like cells in adult mammals.</strong> Vacanti, M.
  1523. P., A. Roy, J. Cortiella, L. Bonassar, and C. A. Vacanti.
  1524. </p>
  1525. <p>
  1526. Am J Ophthalmol 1947, 30: 635-636. <strong>Biogenic Stimulators.</strong> (Editorial) Vail D.
  1527. </p>
  1528. <p>
  1529. Clin Immunol Immunopathol. 1989 Aug;52(2):257-70.<strong>
  1530. Depression of humoral responses and phagocytic functions in vivo and in vitro by fish oil and
  1531. eicosapentanoic acid.</strong> Virella G, Kilpatrick JM, Rugeles MT, Hyman B, Russell R.
  1532. </p>
  1533. <p>
  1534. Reprod Biomed Online. 2005 May;10(5):607-16.<strong>
  1535. Gene expression in the preimplantation embryo: in-vitro developmental changes.
  1536. </strong>
  1537. Wang S, Cowan CA, Chipperfield H, Powers RD.
  1538. </p>
  1539. <p>
  1540. Tissue Eng. 2006 Oct 1; [Epub ahead of print]<strong>
  1541. Effects of Glutamine, Glucose, and Oxygen Concentration on the Metabolism and Proliferation of Rabbit
  1542. Adipose-Derived Stem Cells.</strong> Follmar KE, Decroos FC, Prichard HL, Wang HT, Erdmann D, Olbrich
  1543. KC.
  1544. </p>
  1545. <p>
  1546. J Urol. 2007 Apr;177(4):1568-72. <strong>Over expression of stem cell homing cytokines in urogenital organs
  1547. following vaginal distention.</strong> Woo LL, Hijaz A, Kuang M, Penn MS, Damaser MS, Rackley RR.
  1548. </p>
  1549. <p>
  1550. Med Hypotheses. 1981 Oct;7(10):1241-51. <strong>The histogenesis of glandular neoplasia.</strong> Zajicek G.
  1551. </p>
  1552. <h1>
  1553. <strong>Stem cells, cell culture, and culture: Issues in regeneration
  1554. </strong>
  1555. </h1>
  1556. <p>
  1557. Cell renewal is a factor in all aspects of health and disease, not just in aging and the degenerative
  1558. diseases. Many people are doing valid research relating to cell renewal and regeneration, but its usefulness
  1559. is seriously limited by cultural and commercial constraints. By recovering some of our suppressed
  1560. traditional culture, I think regenerative therapies can be developed quickly, by identifying and eliminating
  1561. as far as possible the main factors that interfere with tissue renewal.
  1562. </p>
  1563. <p>
  1564. Science grew up in the highly authoritarian cultures of western Europe, and even as it contributed to
  1565. cultural change, it kept an authoritarian mystique. Any culture functions as a system of definitions of
  1566. reality and the limits of possibility, and to a great extent the "laws of nature" are decreed so that they
  1567. will harmonize with the recognized laws of society.
  1568. </p>
  1569. <p>
  1570. The practical success of Newton's "laws" of motion when they were applied to ballistics and "rocket science"
  1571. has led many people to value calculation, based on those laws, over evidence. In biology, the idea that an
  1572. organism is "the information it contains in its DNA blueprint" is an extention of this. The organism is
  1573. turned into something like a deductive expression of the law of DNA. This attitude has been disastrous.
  1574. </p>
  1575. <p>
  1576. The old feudal idea of a divine and stable social organization was applied by some people to their idea of
  1577. biological organization, in which each cell (ruled by its nucleus) had its ordained place in the organism,
  1578. with the brain and the "master gland," the pituitary, ruling the subordinate organs, tissues, and cells.
  1579. "Anatomy" was taught from dead specimens, microscope slides, and illustrations in books. Most biologists'
  1580. thoughts about cells in organisms reflect the static imagery of their instruction. (<em>"The histological
  1581. image of these tissues actually reflects an instantaneous picture of cells in a continuous flux."</em>
  1582. Zajicek, 1981.)
  1583. </p>
  1584. <p>
  1585. When a person has playful and observant interactions with natural things, both regularities and
  1586. irregularities will be noticed, and in trying to understand those events, the richness of the experience
  1587. will suggest an expansive range of possibilities. Perception and experimentation lead to understandings that
  1588. are independent of culture and tradition.
  1589. </p>
  1590. <p>
  1591. But the mystique of science easily imposes itself, and distracts our attention from direct interactions with
  1592. things. As we learn to operate lab instruments, we are taught the kinds of results that can be expected, and
  1593. the concepts that will explain and predict the results of our operations. Science, as we learn about it in
  1594. schools and the mass media, is mostly a set of catechisms.
  1595. </p>
  1596. <p>
  1597. Our theories about organisms inform our experiments with cells or tissues that have been isolated from those
  1598. organisms. The conditions for growing cells in dishes are thought of as "physiological," in relation to the
  1599. solution's "physiological osmolarity," "physiological pH," nutrients, oxygenation, temperature, pressure,
  1600. etc. But these concepts of what is physiological derive from the monolithic ideology of the doctrinaire, and
  1601. often fraudulent, mainstream of biological science.
  1602. </p>
  1603. <p>
  1604. The catechismic nature of science has led people to expect some "break-throughs" to occur in certain areas,
  1605. and as authoritarian science has grown into "big science" managed by corporations and governments, those
  1606. break-throughs are generally expected to be produced by the newest and most expensive developments of "high
  1607. technology."
  1608. </p>
  1609. <p>
  1610. But looking closely at the real events and processes in the sciences in the last couple of centuries, it
  1611. turns out that useful advances have been produced mainly by breaking away from authoritarian doctrines, to
  1612. return to common sense and relatively simple direct observations.
  1613. </p>
  1614. <p>
  1615. Although people were cloning animals in the 1960s, it was still widely taught that it was impossible. The
  1616. students of the professors who taught that it was impossible are now saying that it requires high technology
  1617. and new research.
  1618. </p>
  1619. <p>
  1620. For the last 100 years the most authoritative view in biology has been that there are no stem cells in
  1621. adults, that brains, hearts, pancreases and oocytes are absolutely incapable of regeneration. But now,
  1622. people seem to be finding stem cells wherever they look, but there is a mystique of high technology involved
  1623. in finding and using them.
  1624. </p>
  1625. <p>
  1626. Whether it's deliberate or not, the emphasis on stem cell technology has the function of directing attention
  1627. away from traditional knowledge, the way allopathic medicine has de-emphasized the intrinsic ability of
  1628. people to recover from disease.
  1629. </p>
  1630. <p>
  1631. This resembles the way that the Mendel-Morgan gene doctrine was used to suppress the knowledge gained from
  1632. centuries of experience of plant and animal breeders, and to belittle the discoveries of Luther Burbank,
  1633. Paul Kammerer, Trofim Lysenko, and Barbara McClintock. The same type of biochemical process that caused the
  1634. hereditary changes those researchers studied are involved in the differentiation and dedifferentiation of
  1635. stem cells that regulate healing and regeneration.
  1636. </p>
  1637. <p>
  1638. In the 1940s, even children discussed the biological discoveries of the 1920s and 1930s, the work in
  1639. regeneration and adaptation, parthenogenesis, and immortalization. The ideas of J. Loeb, T. Boveri, A.
  1640. Gurwitsch, J. Needham, C.M. Child, A. Carrel, et al., had become part of the general culture.
  1641. </p>
  1642. <p>
  1643. But that real biology was killed by a consortium of industry and government that began a little before the
  1644. second world war. In 1940, the government was supporting research in chemical and biological warfare, and
  1645. with the Manhattan Project the role of government became so large that all of the major research
  1646. universities were affected. Shortly after the war, many researchers from the Manhattan Project were
  1647. redeployed into "molecular genetics," where the engineering attitude was applied to organisms.
  1648. </p>
  1649. <p>
  1650. The simplistic genetic dogmas were compatible with the reductionist engineering approach to the organism.
  1651. The role of the government assured that the universities would subscribe to the basic scientific agenda. The
  1652. atmosphere of that time was described by Carl Lindegren as "The Cold War in Biology" (1966).
  1653. </p>
  1654. <p>
  1655. The disappearance of the field concept in developmental biology was one of the strangest events in the
  1656. history of science. It didn't just fade away, it was "disappeared," in a massive undertaking of social
  1657. engineering. In its absence, stem cells will seem to be a profitable technological marvel, rather than a
  1658. universal life function, with a central role in everything we are and everything we do and can become.
  1659. </p>
  1660. <p>
  1661. Many people have tried to explain aging as a loss of cells, resulting from an intrinsic inability of any
  1662. cell other than a germ cell to multiply more than a certain number of times. More than 40 years ago Leonard
  1663. Hayflick popularized this doctrine in its most extreme form, saying that no cell can divide more than 50
  1664. times unless it is converted into a cancer cell. He and his followers claimed that they had explained why
  1665. organisms must age and die. At the moment the ovum is fertilized, the clock starts ticking for the
  1666. essentially mortal somatic cells.
  1667. </p>
  1668. <p>
  1669. In 1970, it was being seriously proposed that memory was produced by the death of brain cells, in a manner
  1670. analogous to the holes punched in cards to enter data into computers. The cultural dogma made it impossible
  1671. to consider that learning could be associated with the birth of new cells in the adult brain.
  1672. </p>
  1673. <p>
  1674. With the announcement in 1997 of the cloning of the sheep Dolly from a somatic cell taken from a 6 year old
  1675. sheep, there was renewed interest in the idea made famous by Alexis Carrel that all cells are potentially
  1676. immortal, and in the possibility of preserving the vitality of human cells. Within a few months, Hayflick
  1677. began reminding the public that "In the early 1960's we overthrew this dogma after finding that normal cells
  1678. do have a finite replicative capacity." ("During the first half of this century it was believed that because
  1679. cultured normal cells were immortal, aging must be caused by extra-cellular events.") The way Hayflick
  1680. "overthrew" more than 35 years of work at the Rockefeller Institute was by growing one type of cell, a lung
  1681. fibroblast, in culture dishes, and finding that the cultures deteriorated quickly.
  1682. </p>
  1683. <p>
  1684. To draw global conclusions about an organism's development and aging from the degenerative processes seen in
  1685. a single type of cell, grown in isolation from all normal stimuli, would have been treated as nothing but
  1686. wild speculation, except that it occurred within a culture that needed it. No aspect of Hayflick's cell
  1687. culture system could properly be called physiological.
  1688. </p>
  1689. <p>
  1690. Other researchers, simply by changing a single factor, caused great increases in the longevity of the
  1691. cultured cells. Simply using a lower, more natural oxygen concentration, the cells were able to undergo 20
  1692. more divisions. Just by adding niacin, 30 more divisions; vitamin E, 70 more divisions. Excess oxygen is a
  1693. poison requiring constant adaptation.
  1694. </p>
  1695. <p>
  1696. Hayflick also published the observation that, while the cells kept in dishes at approximately body
  1697. temperature deteriorated, cells kept frozen in liquid nitrogen didn't deteriorate, and he concluded that
  1698. "time" wasn't the cause of aging. When I read his comments about the frozen cells, I wondered how anyone of
  1699. normal intelligence could make such stupid statements. Since then, facts that came out because of the
  1700. Freedom of Information Act, cause me to believe that a financial motive guided his thoughts about his
  1701. cultured fibroblasts.
  1702. </p>
  1703. <p>
  1704. Hayflick and his followers have been attacking the idea of anti-aging medicine as quackery. But he is
  1705. closely involved with the Geron corporation, which proposes that genetic alterations relating to telomeres
  1706. may be able to cure cancer and prevent aging. Their claims were reported by CNN as "Scientists discover
  1707. cellular 'fountain of youth'."
  1708. </p>
  1709. <p>
  1710. The "wear and tear" doctrine of aging that derived from the ideology of the gene was reinforced and renewed
  1711. by Hayflick's cell culture observations, and it continued to rule the universities and popular culture.
  1712. </p>
  1713. <p>
  1714. But detailed investigation of skin cell growth showed that cells in the lower layer of the skin divide at
  1715. least 10,000 times in a normal lifetime, and similar processes occur in the lining of the intestine. The
  1716. endometrium and other highly renewable tissues just as obviously violated Hayflick's limit. Transplantation
  1717. experiments showed that pieces of mammary tissue or skin tissue could survive through ten normal lifetimes
  1718. of experimental animals without suffering the effects of aging.
  1719. </p>
  1720. <p>
  1721. Even the liver and adrenal gland are now known to be continuously renewed by "cell streaming," though at a
  1722. slower rate than the skin, conjunctiva, and intestine. Neurogenesis in the brain is now not only widely
  1723. accepted, it is even proposed as a mechanism to explain the therapeutic effects of antidepressants
  1724. (Santarelli, et al., 2003).
  1725. </p>
  1726. <p>
  1727. August Weismann's most influential doctrine said that "somatic cells are mortal, only the germline cells are
  1728. immortal," but he based the doctrine on his mistaken belief that only the "germline" cells contained all the
  1729. genes of the organism. In 1885, to "refute" Darwin's belief that acquired traits could be inherited, he
  1730. promulgated an absolute "barrier" between "germline" and "soma," and invented facts to show that hereditary
  1731. information can flow only from the germline to the somatic cells, and not the other direction. Shortly after
  1732. DNA became popular in the 1950s as "the genetic material," Weismann's barrier was restated as the Central
  1733. Dogma of molecular genetics, that information flows only from DNA to RNA to protein, and never the other
  1734. direction.
  1735. </p>
  1736. <p>
  1737. It was only in 2003, after the reality of cloning was widely recognized, that a few experimenters began to
  1738. investigate the origin of "germline" cells in the ovary, and to discover that they derive from somatic cells
  1739. (Johnson, et al., 2004). With this discovery, the ancient knowledge that a twig (<em>klon</em>, in Greek)
  1740. cut from a tree could grow into a whole tree, bearing fruit and viable seeds, was readmitted to general
  1741. biology, and the Weismann barrier was seen to be an illusion.
  1742. </p>
  1743. <p>
  1744. Millions of people have "explained" female reproductive aging as the consequence of the ovary "running out
  1745. of eggs." Innumerable publications purported to show the exact ways in which that process occurs, following
  1746. the Weismann doctrine. But now that it is clear that adult ovaries can give birth to new oocytes, a new
  1747. explanation for female reproductive aging is needed. It is likely that the same factors that cause female
  1748. reproductive aging also cause aging of other systems and organs and tissues, and that those factors are
  1749. extrinsic to the cells themselves, as Alexis Carrel and others demonstrated long ago. This is a way of
  1750. saying that all cells are potential stem cells. The "niche" in which new cells are born in the streaming
  1751. organism, and the processes by which damaged cells are removed, are physiological issues that can be
  1752. illuminated by the idea of a morphogenetic field.
  1753. </p>
  1754. <p>
  1755. When the post-war genetic engineers took over biological research, the idea of a biophysical field was
  1756. totally abandoned, but after about 15 years, it became necessary to think of problems beyond those existing
  1757. within a single bacterium, namely, the problem of how an ovum becomes and embryo. Francis Crick, of DNA
  1758. fame, who was educated as a physicist, revived (without a meaningful historical context) the idea of a
  1759. diffusion gradient as a simple integrating factor that wouldn't be too offensive to the reductionists. But
  1760. for events far beyond the scale of the egg's internal structure, for example to explain how a nerve axon can
  1761. travel a very long distance to innervate exactly the right kind of cell, the diffusion of molecules loses
  1762. its simplicity and plausibility. (Early in the history of experimental embryology, it was observed that
  1763. electrical fields affect the direction of growth of nerve fibers.)
  1764. </p>
  1765. <p>
  1766. C. M. Child saw a gradient of metabolic activity as an essential component of the morphogenetic field. This
  1767. kind of gradient doesn't deny the existence of diffusion gradients, or other physical components of a field.
  1768. Electrical and osmotic (and electro-osmotic) events are generated by metabolism, and affect other factors,
  1769. including pH, oxidation and reduction, cell motility and cell shape, ionic selectivity and other types of
  1770. cellular selectivity and specificity. Gradients of DNA methylation exist, and affect the expression of
  1771. inherited information.
  1772. </p>
  1773. <p>
  1774. Methylation decreases the expression of particular genes, and during the differention of cells in the
  1775. development of an embryo, genes are methylated and demethylated as the cell adapts to produce the proteins
  1776. that are involved in the structure and function of a particular tissue. Methylation (which increases a
  1777. molecule's affinity for fats) is a widespread process in cells, and for example regulates cellular
  1778. excitability. It is affected by diet and a variety of stresses.
  1779. </p>
  1780. <p>
  1781. DNA methylation patterns are normally fairly stable, and can help to account for the transgenerational
  1782. transmission of acquired adaptations, and for neonatal imprinting that can last a lifetime. But with injury,
  1783. stress, and aging, the methylation patterns of differentiated tissues can be changed, contributing to the
  1784. development of tumors, or to the loss of cellular functions. Even learning can change the methylation of
  1785. specific genes. During <em>in vitro</em> culture, the enzymes of gene methylation are known to be increased,
  1786. relative to their normal activity (Wang, et al., 2005).
  1787. </p>
  1788. <p>
  1789. The phenomenon of "gene" methylation in response to environmental and metabolic conditions may eventually
  1790. lead to the extinction of the doctrine that "cells are controlled by their genes."
  1791. </p>
  1792. <p>
  1793. During successful adaptation to stress, cells make adjustments to their metabolic systems (for example with
  1794. a holistic change of the degree of phosphorylation, which increases molecules' affinity for water), and
  1795. their metabolic processes can contribute to changes in their state of differentiation. Some changes may lead
  1796. to successful adaptation (for example by producing biogenic stimulators that stimulate cell functioning and
  1797. regeneration), others to failed adaptation. Even the decomposition of cells can release substances that
  1798. contribute to the adaptation of surrounding cells, for example when sphingosines stimulate the production of
  1799. stem cells.
  1800. </p>
  1801. <p>
  1802. DNA methylation is just one relatively stable event that occurs in relation to a metabolic field.
  1803. Modifications of histones (regulatory proteins in chromosomes, which are acetylated as well as methylated)
  1804. and structural-contractile filaments also contribute to the differentiation of cells, but the pattern of DNA
  1805. methylation seems to guide the methylation of histones and the structure of the chromosomes (Nan, et al.,
  1806. 1998).
  1807. </p>
  1808. <p>
  1809. Steroids and phospholipids, neurotransmitters and endorphins, ATP, GTP, other phosphates, retinoids, NO and
  1810. CO2--many materials and processes participate in the coherence of the living state, the living substance.
  1811. Carbon dioxide, for example, by binding to lysine amino groups in the histones, will influence their
  1812. methylation. Carbon dioxide is likely to affect other amino groups in the chromosomes.
  1813. </p>
  1814. <p>
  1815. The number and arrangement of mitochondria is an important factor in producing and maintaining the metabolic
  1816. gradients. Things that decrease mitochondrial energy production--nitric oxide, histamine, cytokines,
  1817. cortisol--increase DNA methylation. Decreased gene expression is associated with reduced respiratory energy.
  1818. It seems reasonable to guess that increased gene expression would demand increased availability of energy.
  1819. </p>
  1820. <p>
  1821. As an ovum differentiates into an organism, cells become progressively more specialized, inhibiting the
  1822. expression of many genes. Less energy is needed by stably functioning cells, than by actively adapting
  1823. cells. A.I. Zotin described the process of maturing and differentiating as a decrease of entropy, an
  1824. increase of order accompanying a decreased energy expenditure. The entropic egg develops into a less
  1825. entropic embryo with a great expenditure of energy.
  1826. </p>
  1827. <p>
  1828. The partially differentiated stem cell doesn't go through all the stages of development, but it does expend
  1829. energy intensely as it matures.
  1830. </p>
  1831. <p>
  1832. The restoration of energy is one requirement for the activation of regeneration. When a hormone such as
  1833. noradrenaline or insulin causes a stem cell to differentiate in vitro, it causes new mitochondria to form.
  1834. This is somewhat analogous to the insertion of mitochondria into the ripening oocyte, by the nurse cells
  1835. that surround it. The conditionally decreased entropy of maturation is reversed, and when sufficient
  1836. respiratory energy is available, the renewed and refreshed cell will be able to renew an appropriate degree
  1837. of differentiation.
  1838. </p>
  1839. <p>
  1840. When simple organisms, such as bacteria, fungi, or protozoa are stressed, for example by the absence of
  1841. nutrients or the presence of toxins, they slow their metabolism, and suppress the expression of genes,
  1842. increasing the methylation of DNA, to form resistant and quiescent spores. Our differentiated state doesn't
  1843. go to the metabolic extreme seen in sporulation, but it's useful to look at maturity and aging in this
  1844. context, because it suggests that the wrong kind of stress decreases the ability of the organism to adapt,
  1845. by processes resembling those in the spore-forming organisms.
  1846. </p>
  1847. <p>
  1848. Charles Vacanti, who has grown cartilage from cells taken from 100 year old human cartilage, believes our
  1849. tissues contain "spore cells," very small cells with slow metabolism and extreme resistance to heat, cold,
  1850. and starvation.
  1851. </p>
  1852. <p>
  1853. If the slowed metabolism of aging, like that of sporulating cells, is produced by a certain kind of stress
  1854. that lowers cellular energy and functions, it might be useful to think of the other stages of the stress
  1855. reaction in relation to the production of stem cells. Selye divided stress into a first stage of shock,
  1856. followed by a prolonged adaptation, which could sometimes end in exhaustion. If the maturity of
  1857. differentiated functioning is equivalent to the adaptation phase, and cellular decline and disintegration is
  1858. the exhaustion phase, then the shock-like reaction would correspond to the birth of new stem cells.
  1859. </p>
  1860. <p>
  1861. Selye described estrogen's effects as equivalent to the shock-phase of stress. Estrogen's basic action is to
  1862. make oxygen unavailable, lowering the oxygen tension of the tissues, locally and temporarily. Like nitric
  1863. oxide, which is produced by estrogenic stimulation, estrogen interferes with energy production, so if its
  1864. stimulation is prolonged, cells are damaged or killed, rather than being stimulated to regenerate.
  1865. </p>
  1866. <p>
  1867. Extrinsic factors elicit renewal, the way stress can elicit adaptation. While aging cells can't use the
  1868. oxygen that is present, a scarcity of oxygen can serve as a stimulus to maximize the respiratory systems.
  1869. Brief oxygen deprivation excites a cell, causes it to swell, and to begin to divide.
  1870. </p>
  1871. <p>
  1872. Oxygen deprivation, as in the normally hypoxic bone marrow, stimulates the formation of stem cells, as well
  1873. as the biogenesis of mitochondria. As the newly formed cells, with abundant mitochondria, get adequate
  1874. oxygen, they begin differentiation.
  1875. </p>
  1876. <p>
  1877. Form, based on cellular differentiation, follows function--a vein transplanted into an artery develops
  1878. anatomically into an artery, a colon attached directly to the anus becomes a new rectum with its appropriate
  1879. innervation, a broken bone restructures to form a normal bone. If the bladder is forced to function more
  1880. than normal, by artificially keeping it filled, its thin wall of smooth muscle develops into a thick wall of
  1881. striated muscle that rhythmically contracts, like the heart. If a tadpole is given a vegetarian diet, the
  1882. absorptive surface of its digestive system will develop to be twice the size of those that are fed meat.
  1883. Pressure, stretching, and pulsation are among the signals that guide cells' differentiation.
  1884. </p>
  1885. <p>
  1886. Very early in the study of embryology it was noticed that the presence of one tissue sometimes induced the
  1887. differentiation of another kind, and also that there were factors in embryonic tissues that would stimulate
  1888. cell division generally, and others that could inhibit the growth of a particular tissue type. Diffusable
  1889. substances and light were among the factors identified as growth regulators.
  1890. </p>
  1891. <p>
  1892. Extracts of particular tissues were found to suppress the multiplication of cells in that type of tissue, in
  1893. adult animals as well as in embryos. In the 1960s, the tissue-specific inhibitors were called chalones.
  1894. </p>
  1895. <p>
  1896. The brain's development is governed by the presence in the organism of the body part to which it
  1897. corresponds, such as the eyes or legs. The number of cells in a particular part of the nervous system is
  1898. governed by the quantity of nervous input, sensory or motor, that it receives. An enriched environment
  1899. causes a bigger brain to grow. Sensory nerve stimulation of a particular region of the brain causes nerve
  1900. cells to migrate to that area (a process called neurobiotaxis; deBeers, 1927), but nerve stimulation also
  1901. causes mitochondria to accumulate in stimulated areas. Nerve activity has a trophic, sustaining influence on
  1902. other organs, as well as on the brain. Nerve stimulation, like mechanical pressure or stretching, is an
  1903. important signal for cellular differentiation.
  1904. </p>
  1905. <p>
  1906. When stem cells or progenitor cells are called on to replace cells in an organ, they are said to be
  1907. "recruited" by that organ, or to "home" to that organ, if they are coming from elsewhere. Traditionally, the
  1908. bone marrow has been considered to be the source of circulating stem cells, but it now appears that a
  1909. variety of other less differentiated cells can be recruited when needed. Cells from the blood can repair the
  1910. endothelium of blood vessels, and endothelial cells can become mesenchymal cells, in the heart, for example.
  1911. </p>
  1912. <p>
  1913. The standard doctrine about cancer is that a tumor derives from a single mutant cell, but it has been known
  1914. for a long time that different types of cell, such as phagocytes and mast cells, usually reside in tumors,
  1915. and it is now becoming clear that tumors recruit cells, including apparently normal cells, from other parts
  1916. of the same organ. For example, a brain tumor of glial cells, a glioma, recruits glial cells from
  1917. surrounding areas of the brain, in a process that's analogous to the embryological movement of nerve cells
  1918. to a center of excitation. Each tumor, in a sense, seems to be a center of excitation, and its fate seems to
  1919. depend on the nature of the cells that respond to its signals.
  1920. </p>
  1921. <p>
  1922. To accommodate some of the newer facts about tumors, the cancer establishment has begun speaking of "the
  1923. cancer stem cell" as the real villain, the origin of the tumor, while the bulk of the tumor is seen to be
  1924. made up of defective cells that have a short life-span. But if we recognize that tumors are recruiting cells
  1925. from beyond their boundaries, this process would account for the growth and survival of a tumor even while
  1926. most of its cells are inert and dying, without invoking the invisible cancer stem cell. And this view, that
  1927. it is the field which is defective rather than the cell, is consistent with the evidence which has been
  1928. accumulating for 35 years that tumor cells, given the right environment, can differentiate into healthy
  1929. cells. (Hendrix, et al., 2007)
  1930. </p>
  1931. <p>
  1932. Simply stretching an organ (Woo, et al., 2007) is stimulus enough to cause it to recruit cells from the
  1933. bloodstream, and will probably stimulate multiplication in its local resident cells, too. Every "cancer
  1934. field" probably begins as a healing process, and generally the healing and regeneration are at least
  1935. partially successful.
  1936. </p>
  1937. <p>
  1938. When an organ--the brain, heart, liver, or a blood vessel--is inflamed or suffering from an insufficient
  1939. blood supply, stem cells introduced into the blood will migrate specifically to that organ.
  1940. </p>
  1941. <p>
  1942. Organ specific materials (chalones) are known to circulate in the blood, inhibiting cell division in cells
  1943. typical to that organ, but it also seems that organ specific materials are secreted by a damaged organ, that
  1944. help to prepare stem cells for their migration into that organ. When undifferentiated cells are cultured
  1945. with serum from a person with liver failure, they begin to differentiate into liver cells.
  1946. </p>
  1947. <p>
  1948. It is still common to speak of each organ as having a "clonal origin" in the differentiating embryo, as a
  1949. simple expansion of a certain embryonic anlage. The implication of this way of thinking is that
  1950. differentiation is <em>determination</em> in an irreversible sense. This is another case of medical ideas
  1951. being based on images of fixed histological material. Normal cells, including nerve and muscle cells, can
  1952. change type, with connective tissue cells becoming nerve cells, nerve cells becoming muscle and fiber cells,
  1953. fat, fiber, and muscle cells redifferentiating, for example.
  1954. </p>
  1955. <p>
  1956. Cell movements in solid tissues aren't limited to the short distances between capillaries and the tissues
  1957. nourished by those capillaries, rather, cells can migrate much greater distances, without entering the
  1958. bloodstream. The speed of a single cell moving by ameboid motion can be measured by watching cells on a
  1959. glass slide as they move toward food, or by watching cells of the slime mold Dictyostelium when they are
  1960. aggregating, or by watching the pigment cells in and around moles or melanomas, under the influence of
  1961. hormones. At body temperature, a single cell can crawl about an inch per day. Waves or spots of brown
  1962. pigment can be seen migrating through the skin away from a mole, preceding the disintegration of the mole
  1963. under the influence of progesterone or DHEA. Under ordinary conditions, pigment cells can sometimes be seen
  1964. migrating into depigmented areas of skin, during the recovery of an area affected by vitiligo. These
  1965. organized movements of masses of cells happen to be easy to see, but there is evidence that other types of
  1966. cell can reconstruct tissues by their ameboid movements, when circumstances are right. Tumors or tissue
  1967. abnormalities can appear or disappear with a suddenness that seems impossible to people who have studied
  1968. only fixed tissue preparations.
  1969. </p>
  1970. <p>
  1971. Stimulation is anabolic, building tissue, when the organism is adapting to the stimulation. Unused
  1972. structures in cells and tissues are always being recycled by metabolic processes. When tissues are injured
  1973. and become unable to function, some of their substances stimulate the growth of replacement cells.
  1974. </p>
  1975. <p>
  1976. Some types of injury or irritation can activate regenerative processes. A dermatology journal described the
  1977. case of an old man who had been bald for many years who fell head-first into his fireplace. As his burned
  1978. scalp healed, new hair grew. In the U.S., experimenters (Ito, et al., 2007) have found that injuring the
  1979. skin of mice stimulates the formation of stem cells that are able to become hair follicle cells, supporting
  1980. the regeneration of cells that had been absent. A brief exposure to estrogen, and other stress related
  1981. signals (nitric oxide, endorphin, prostaglandins) can initiate stem cell proliferation.
  1982. </p>
  1983. <p>
  1984. In the years after the first world war, Vladimir Filatov, who developed techniques of reconstructive
  1985. surgery, including corneal transplants, found that cold storage of tissues (for example, corneas from
  1986. cadavers) caused them to function better than fresh tissues, and he found that these stressed tissues would
  1987. often spread a healing influence out into the surrounding tissues. Extracts of stressed tissues produced
  1988. similar effects.
  1989. </p>
  1990. <p>
  1991. L.V. Polezhaev began studying the regenerative capacities of mammals in the late 1940s, and his work showed
  1992. that processes similar to embryonic induction are involved in the organism's responses to damaged tissues.
  1993. For example, when a piece of killed muscle tissue is enclosed in a capsule ("diffusion chamber") that
  1994. permits molecules, but no cells, to diffuse through it, and implanted subcutaneously, it had no inductive
  1995. effect on surrounding cells. But when the pores of the capsule allowed cells to enter, skeletal muscle
  1996. formed where the dead tissue had been, and tissue resembling heart muscle formed outside the capsule.
  1997. Phagocytosis had been essential for the induction to occur.
  1998. </p>
  1999. <p>
  2000. Macrophages are ordinarily thought of as "antigen-presenting cells" that help to activate the specific
  2001. immune responses. But apparently phagocytosis is involved in the replacement of damaged tissues, by
  2002. recruiting or inducing the differentiation of replacement cells. The phagocytosis function isn't limited to
  2003. the blood cells commonly called phagocytes; even nerve cells can ingest particles and fragments of damaged
  2004. tissues.
  2005. </p>
  2006. <p>
  2007. Many factors regulate the process of phagocytosis. Stress and lipid peroxidation decrease phagocytosis
  2008. (Izg"t-Uysal, et al., 2004), and also damage mitochondria and inhibit cell renewal.
  2009. </p>
  2010. <p>
  2011. Unsaturated fatty acids inhibit phagocytosis (Guimaraes, et al., 1991, 1992; Costa Rosa, et al., 1996;
  2012. Virella, et al., 1989; Akamatsu, et al., 1990), and suppress mitochondrial function (Gomes, et al., 2006).
  2013. Dietary restriction activates phagocytosis (Moriguchi, et al., 1989), suggesting that normal diets contain
  2014. suppressive materials.
  2015. </p>
  2016. <p>
  2017. Subnormal temperatures cause a shift from phagocytosis to inflammation. Light, especially the red light
  2018. which penetrates easily into tissues, activates the formation of new cells as well as their differentiation.
  2019. It affects energy production, increasing the formation of mitochondria, and the activity of the DNA
  2020. methyltransferase enzymes. Red light accelerates wound healing, and improves the quality of the scar,
  2021. reducing the amount of fibrosis. The daily cycling between darkness and light is probably an important
  2022. factor in regulating the birth and differentiation of cells..
  2023. </p>
  2024. <p>
  2025. Darkness suppresses mitochondrial function, and light activates it. Prolonged darkness increases cortisol,
  2026. and cortisol (which makes cells more susceptible to excitotoxic death) inhibits stem cell proliferation (Li,
  2027. et al., 2006; Liu, et al., 2003). Neurogenesis is suppressed by stress, and increased by spontaneous
  2028. activity, and has a circadian rhythm. Aging and depression both involve a diminished ability to rhythmically
  2029. lower the production of cortisol. Cell renewal requires a rhythmic decrease in the exposure to cortisol..
  2030. </p>
  2031. <p>
  2032. In the spring, with increased day length, the brains of song-birds grow, with an increased proliferation of
  2033. cells in the part of the brain involved in singing. The production of progesterone increases in most animals
  2034. in the spring, and it is the main hormone responsible for the birds' brain growth.
  2035. </p>
  2036. <p>
  2037. Progesterone and its metabolites protect brain cells against injury, and improve the brain's ability to
  2038. recover after traumatic injury (Brinton and Wang, 2006). In the 1960s, Marion Diamond's group showed that
  2039. environmental enrichment, or progesterone, caused brains to grow larger, and that these changes were passed
  2040. on to descendants in a cumulative, increasing way. This suggests that the factors that promote neurogenesis
  2041. also cause changes in the apparatus of reproduction and inheritance, that support the development of the
  2042. brain--probably including the methylation system, which is involved in regulating genes, and also mood and
  2043. behavior.
  2044. </p>
  2045. <p>
  2046. Women's monthly cycles, in which a brief estrogen dominance is followed by sustained exposure to
  2047. progesterone, are probably an important factor in the renewal of the cells of the brain and other organs, as
  2048. well as those of the reproductive organs. The daily rhythms of hormones and metabolism are known to be
  2049. involved in the regulation of cell renewal.
  2050. </p>
  2051. <p>
  2052. Environmental enrichment, learning, high altitude, and thyroid hormone promote the formation of new
  2053. mitochondria, and stimulate stem cell proliferation. At least in some laboratories, 20% oxygen,
  2054. approximately the amount as in the atmosphere, suppresses the proliferation of stem cells (He, et al.,
  2055. 2007). This was the unphysiologically high concentration of oxygen used in Hayflick's cell cultures. At high
  2056. altitudes, where tissues are exposed to less oxygen, and more carbon dioxide, there is a lower incidence of
  2057. all the degenerative diseases, including cancer, heart disease, and dementia. Improved cellular energy
  2058. production and more active renewal of cells would probably account for those differences.
  2059. </p>
  2060. <p>
  2061. For Crick, the idea of a diffusion gradient to explain embryonic development was simply an extension of his
  2062. reductionist orientation, in which diffusing molecules induced or inhibited bacterial genes, and in which
  2063. genes controlled cells. For people with that orientation, the adaptive mutations described by Carl
  2064. Lindegren, and later by John Cairns, or even the stress-induced variability described by Lysenko, Strong,
  2065. and McClintock, were heretical. Polezhaev's demonstration that cells could do something that molecular
  2066. diffusion didn't do, threatened to take biology away from the reductionists. If the organism's adaptation to
  2067. the environment involves changing its own genes, Crick's paradigm fails.
  2068. </p>
  2069. <p>
  2070. Crick's Central Dogma, derived from the ideology that produced Weismann's Barrier, has been invoked by
  2071. generations of professors who wanted to deny the possibility of adaptive tissue renewal and regeneration.
  2072. Without the dogma, new ideas about aging and disease will be needed. If somatic cells can adjust their
  2073. genes, and if they can also differentiate into new eggs and sperms, new ideas about inheritance of acquired
  2074. traits will be needed.
  2075. </p>
  2076. <p>
  2077. The replacement of injured cells means that mutations need not accumulate. Cell renewal with elimination of
  2078. mutant cells has been observed in sun-damaged skin simply by stopping the damage, and mitochondria with
  2079. damaged DNA can be replaced by healthy mitochondria simply by doing the right kind of exercise.
  2080. </p>
  2081. <p>
  2082. The regulation of cell renewal probably involves all of the processes of life, but there are a few simple,
  2083. interacting factors that suppress renewal. The accumulation of polyunsaturated fats, interacting with a high
  2084. concentration of oxygen, damages mitochondria, and causes a chronic excessive exposure to cortisol. With
  2085. mitochondrial damage, cells are unable to produce the progesterone needed to oppose cortisol and to protect
  2086. cells.
  2087. </p>
  2088. <p>
  2089. Choosing the right foods, the right atmosphere, the right mental and physical activities, and finding the
  2090. optimal rhythms of light, darkness, and activity, can begin to alter the streaming renewal of cells in all
  2091. the organs. Designing a more perfect environment is going to be much simpler than the schemes of the genetic
  2092. engineers.
  2093. </p>
  2094. <p><h3>REFERENCES</h3></p>
  2095. <p>
  2096. Growth 43, 58-61, 1979. <strong>The effect of progesterone on brain and body growth of chick
  2097. embryos.</strong> G. Ahmad and S. Zamenhof. [This showed that progesterone, added during the time of
  2098. active neuronal proliferation, increased the chicks' brain weight, while the stress hormone, corticosterone,
  2099. reduced the weight.]
  2100. </p>
  2101. <p>
  2102. J Invest Dermatol. 1990 Sep;95(3):271-4. <strong>Suppressive effects of linoleic acid on neutrophil oxygen
  2103. metabolism and phagocytosis.</strong> Akamatsu H, Komura J, Miyachi Y, Asada Y, Niwa Y.
  2104. </p>
  2105. <p>
  2106. Curr Alzheimer Res. 2006 Feb;3(1):11-7. <strong>Preclinical analyses of the therapeutic potential of
  2107. allopregnanolone to promote neurogenesis in vitro and in vivo in transgenic mouse model of Alzheimer's
  2108. disease.</strong> Brinton RD, Wang JM. "Herein, we present data to support a preclinical proof of
  2109. concept for the therapeutic potential of allopregnanolone to promote neurogenesis. Our recent work has
  2110. demonstrated that the neuroactive progesterone metabolite, allopregnanolone
  2111. (3alpha-hydroxy-5alpha-pregnan-20-one), (APalpha) induced, in a dose dependent manner, a significant
  2112. increase in proliferation of neuroprogenitor cells (NPCs) derived from the rat hippocampus and human neural
  2113. stem cells (hNSM) derived from the cerebral cortex [1]." "The in vitro and in vivo neurogenic properties of
  2114. APalpha coupled with a low molecular weight, easy penetration of the blood brain barrier and lack of
  2115. toxicity, are key elements required for developing APalpha as a neurogenic / regenerative therapeutic for
  2116. restoration of neurons in victims of Alzheimer's disease."
  2117. </p>
  2118. <p>
  2119. Arch Biochem Biophys. 1996 Jan 1;325(1):107-12.<strong>
  2120. Thyromimetic action of the peroxisome proliferators clofibrate, perfluorooctanoic acid, and
  2121. acetylsalicylic acid includes changes in mRNA levels for certain genes</strong>
  2122. <strong>
  2123. involved in mitochondrial biogenesis.</strong> Cai Y, Nelson BD, Li R, Luciakova K, dePierre JW.
  2124. </p>
  2125. <p>
  2126. Biochem Mol Biol Int. 1996 Nov;40(4):833-42. <strong>The effect of N-3 PUFA rich diet upon macrophage and
  2127. lymphocyte metabolism and function.</strong> Costa Rosa LF, Safi DA, Guimar"es AR.
  2128. </p>
  2129. <p>
  2130. G. R. de Beer, <strong><em>An Introducton to Experimental Embryology,</em></strong>
  2131. Oxford, 1926.
  2132. </p>
  2133. <p>
  2134. Biol. Rev. 1927;2:137-197, <strong>The mechanics of verterate development. </strong>
  2135. de Beer GR.
  2136. </p>
  2137. <p>
  2138. Vrach delp. 1937, 20: 803-820. <strong>Summary of 20 years' achievements in ophthalmology.</strong>
  2139. Filatov VP.
  2140. </p>
  2141. <p>
  2142. Vestnik oftal. 1938, 12: 107-159.<strong>
  2143. Tissue transplantation in intra-ocular diseases.</strong> Filatov VP.
  2144. </p>
  2145. <p>
  2146. Med zhur 1937, 9: 847-853.<strong>
  2147. Intramuscular injections of cod liver oil in therapy of pigmented retinitis.</strong> Filatov VP,
  2148. Verbitska E A.
  2149. </p>
  2150. <p>
  2151. Am Rev Soviet Med. 1946, 3: 388-395.<strong>
  2152. The treatment of retinitis pigmentosa with intramuscular injection of cod liver oil.</strong> Filatov
  2153. VP, Verbitska EA.
  2154. </p>
  2155. <p>
  2156. Am Rev Soviet Med 1946, 3: 395-397. <strong>Retinitis pigmentosa.</strong> Filatov VP.
  2157. </p>
  2158. <p>
  2159. Am Rev Soviet Med 1946, 3: 397-398.<strong>
  2160. The implantation of preserved placenta in retinitis pigmentosa.</strong> Filatov VP Verbitska EA.
  2161. </p>
  2162. <p>
  2163. Hippocampus. 2006;16(3):225-32.<strong>
  2164. Gonadal hormone modulation of hippocampal neurogenesis in the adult.
  2165. </strong>Galea LA, Spritzer MD, Barker JM, Pawluski JL. <strong>
  2166. Estradiol, the most potent estrogen, initially enhances and subsequently suppresses cell proliferation
  2167. in the dentate gryus of adult female rodents.</strong>
  2168. </p>
  2169. <p>
  2170. Glia. 1999 Feb 1;25(3):247-55. <strong>Cerebellar astrocytes treated by thyroid hormone modulate neuronal
  2171. proliferation.</strong> Gomes FC, Maia CG, de Menezes JR, Neto VM. "Thyroid hormones are important for
  2172. neurogenesis and gliogenesis during brain development. We have previously demonstrated that triiodothyronine
  2173. (T3) treatment induced proliferation in primary culture astrocytes derived from the cerebellum of neonatal
  2174. rats." "Interestingly, the cerebellar neuronal population increased by 60-80% in T3CM."
  2175. </p>
  2176. <p>
  2177. Biochem Int. 1992 Jun;27(1):9-16. <strong>Metabolic and functional changes in macrophages of rats fed
  2178. polyunsaturated or saturated fatty acid rich-diets during ageing.
  2179. </strong>Guimar"es AR, Costa Rosa LF, Safi DA, Curi R.
  2180. </p>
  2181. <p>
  2182. Biochem Int. 1991 Feb;23(3):533-43. <strong>Effect of polyunsaturated (PUFA n-6) and saturated fatty
  2183. acids-rich diets on macrophage metabolism and function.</strong>
  2184. Guimar"es AR, Costa Rosa LF, Sitnik RH, Curi R.
  2185. </p>
  2186. <p>
  2187. Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2007 Apr;15(2):433-6. <strong>[Effect of hypoxia on mesenchymal stem
  2188. cells - review.]</strong> [Article in Chinese] He MC, Li J, Zhao CH.
  2189. </p>
  2190. <p>
  2191. Nat Rev Cancer. 2007 Apr;7(4):246-55. <strong>Reprogramming metastatic tumour cells with embryonic
  2192. microenvironments.</strong> Hendrix MJ, Seftor EA, Seftor RE, Kasemeier-Kulesa J, Kulesa PM, Postovit
  2193. LM. "Aggressive tumour cells share many characteristics with embryonic progenitors, contributing to the
  2194. conundrum of tumour cell plasticity." "This Review will summarize the embryonic models used to reverse the
  2195. metastatic melanoma phenotype, and highlight the prominent signalling pathways that have emerged as
  2196. noteworthy targets for future consideration."
  2197. </p>
  2198. <p>
  2199. FEBS Lett. 1973 May 15;32(1):1-8.<strong>
  2200. Chalones. Specific endogenous mitotic inhibitors.</strong> Houck JC, Hennings H.
  2201. </p>
  2202. <p>
  2203. Med Hypotheses. 2005;64(6):1138-43. <strong>Melatonin seems to be a mediator that transfers the
  2204. environmental stimuli to oocytes for inheritance of adaptive changes through epigenetic inheritance
  2205. system.</strong> Irmak MK, Topal T, Oter S.
  2206. </p>
  2207. <p>
  2208. Nature. 2007 May 17;447(7142):316-20. <strong>Wnt-dependent de novo hair follicle regeneration in adult
  2209. mouse skin after wounding.
  2210. </strong>
  2211. Ito M, Yang Z, Andl T, Cui C, Kim N, Millar SE, Cotsarelis G.
  2212. </p>
  2213. <p>
  2214. Cell Biol Int. 2004;28(7):517-21. <strong>Effect of stress-induced lipid peroxidation on functions of rat
  2215. peritoneal macrophages.</strong> Izg"t-Uysal VN, Tan R, B"lb"l M, Derin N.
  2216. </p>
  2217. <p>
  2218. J Cereb Blood Flow Metab. 2007 Mar 28;<strong>
  2219. Regeneration and plasticity in the brain and spinal cord.</strong> Johansson BB.
  2220. </p>
  2221. <p>
  2222. Nature, 428, 145 - 150, (2004). Johnson, J., Canning, J., Kaneko, T., Pru, J.K. &amp; Tilly, J.L.
  2223. </p>
  2224. <p>
  2225. Annals of Ophthalmology No. 1, 2005, p. 54, <strong>Life devoted to fight against blindness</strong> (on the
  2226. 130th birthday anniversary of V. P. Filatov) Knopov M. Sh., Klyasov A. V.
  2227. </p>
  2228. <p>
  2229. R. Levi-Montalcini, <strong>"Neuronal regeneration in vitro," </strong>
  2230. pages 54-65 in Windle,<em> Regeneration in the Central Nervous System,</em>
  2231. C. C. Thomas, 1955.
  2232. </p>
  2233. <p>
  2234. Neurobiol Aging. 2006 Nov;27(11):1705-14. Epub 2005 Nov 4.<strong>
  2235. Salivary cortisol and memory function in human aging.</strong> Li G, Cherrier MM, Tsuang DW, Petrie EC,
  2236. Colasurdo EA, Craft S, Schellenberg GD, Peskind ER, Raskind MA, Wilkinson CW.
  2237. </p>
  2238. <p>
  2239. Med Hypotheses. 2007 Mar 27; [Epub ahead of print] <strong>Effects of hypoxia on proliferation and
  2240. differentiation of myoblasts.</strong> Li X, Zhu L, Chen X, Fan M.
  2241. </p>
  2242. <p>
  2243. Exp Neurol. 2003 Nov;184(1):196-213. <strong>Suppression of hippocampal neurogenesis is associated with
  2244. developmental stage, number of perinatal seizure episodes, and glucocorticosteroid level.</strong> Liu
  2245. H, Kaur J, Dashtipour K, Kinyamu R, Ribak CE, Friedman LK.
  2246. </p>
  2247. <p>
  2248. J Nutr Sci Vitaminol (Tokyo). 1989 Feb;35(1):49-59.<strong>
  2249. Effects of dietary restriction on cellular immunity in rats.</strong> Moriguchi S, Toba M, Kishino Y.
  2250. </p>
  2251. <p>
  2252. Nature. 1998 May 28;393(6683):386-9. <strong>Transcriptional repression by the methyl-CpG-binding protein
  2253. MeCP2 involves a histone deacetylase complex.</strong> Nan X, Ng HH, Johnson CA, Laherty CD, Turner BM,
  2254. Eisenman RN, Bird A.
  2255. </p>
  2256. <p>
  2257. L. V. Polezhaev and E. N. Karnaukhova, <strong>"Stimulation of physiologic regeneration of nervous tissue of
  2258. the cerebral cortex and its significance for biogenic therapy of neuro-mental diseases," pages 86-116 in
  2259. </strong>
  2260. <em>Sbornik: Klinicheskie eksperimentalnye osnovy biogennoi terapii psikhozov</em>,<strong> </strong>
  2261. 1962.
  2262. </p>
  2263. <p>
  2264. Doklady AN SSSR 150, 430-433, 1963., <strong>"Stimulation of nerve cell reproduction of cerebral cortex in
  2265. mammals,"</strong> L. V. Polezhaev and E. N. Karnaukhove
  2266. </p>
  2267. <p>
  2268. L. V. Polezhaev, <strong><em>Loss and Restoration of Regenerative Capacity in Tissues and Organs of
  2269. Animals,</em></strong> page 219, 1972.
  2270. </p>
  2271. <p>
  2272. J Hirnforsch 1991;32(5):659-664. <strong>Normalization of protein synthesis and the structure of brain
  2273. dystrophic neurons after the action of hypoxia, 10% NaCl and organ-specific RNA.</strong> Polezhaev LV,
  2274. Cherkasova LV, Vitvitsky VN, Timonin AV <strong>"Transplantation of embryonic nervous tissue (ENT) in one of
  2275. the hemispheres normalizes all the above abnormalities observed in some neurologic and mental diseases
  2276. in humans."</strong>
  2277. <strong>
  2278. "At the beginning 10% NaCl increased the destruction of brain cortical neurons and then stimulated
  2279. protein synthesis in them.</strong> RNA injections stimulated the synthesis in cortical neurons and
  2280. normalized their structure. Thus, we propose a safe and simple method for normalization of dystrophic
  2281. neurons which can be used after certain improvement for curing neurodegenerative and neuropsychic diseases
  2282. in humans."
  2283. </p>
  2284. <p>
  2285. Science. 2003 Aug 8;301(5634):757. <strong>Requirement of hippocampal neurogenesis for the behavioral
  2286. effects of antidepressants.</strong> Santarelli L, Saxe M, Gross C, Surget A, Battaglia F, Dulawa S,
  2287. Weisstaub N, Lee J, Duman R, Arancio O, Belzung C, Hen R.
  2288. </p>
  2289. <p>
  2290. Chin J Traumatol. 2002 Aug;5(4):246-9. <strong>Experimental study on He-Ne laser irradiation to inhibit scar
  2291. fibroblast growth in culture.</strong>
  2292. Shu B, Wu Z, Hao L, Zeng D, Feng G, Lin Y.
  2293. </p>
  2294. <p>
  2295. J Cell Biochem 2001; 80:455-60.<strong>
  2296. Identification and initial characterization of spore-like cells in adult mammals.</strong> Vacanti, M.
  2297. P., A. Roy, J. Cortiella, L. Bonassar, and C. A. Vacanti.
  2298. </p>
  2299. <p>
  2300. Am J Ophthalmol 1947, 30: 635-636. <strong>Biogenic Stimulators.</strong> (Editorial) Vail D.
  2301. </p>
  2302. <p>
  2303. Clin Immunol Immunopathol. 1989 Aug;52(2):257-70.<strong>
  2304. Depression of humoral responses and phagocytic functions in vivo and in vitro by fish oil and
  2305. eicosapentanoic acid.</strong> Virella G, Kilpatrick JM, Rugeles MT, Hyman B, Russell R.
  2306. </p>
  2307. <p>
  2308. Reprod Biomed Online. 2005 May;10(5):607-16.<strong>
  2309. Gene expression in the preimplantation embryo: in-vitro developmental changes.
  2310. </strong>
  2311. Wang S, Cowan CA, Chipperfield H, Powers RD.
  2312. </p>
  2313. <p>
  2314. Tissue Eng. 2006 Oct 1; [Epub ahead of print]<strong>
  2315. Effects of Glutamine, Glucose, and Oxygen Concentration on the Metabolism and Proliferation of Rabbit
  2316. Adipose-Derived Stem Cells.</strong> Follmar KE, Decroos FC, Prichard HL, Wang HT, Erdmann D, Olbrich
  2317. KC.
  2318. </p>
  2319. <p>
  2320. J Urol. 2007 Apr;177(4):1568-72. <strong>Over expression of stem cell homing cytokines in urogenital organs
  2321. following vaginal distention.</strong> Woo LL, Hijaz A, Kuang M, Penn MS, Damaser MS, Rackley RR.
  2322. </p>
  2323. <p>
  2324. Med Hypotheses. 1981 Oct;7(10):1241-51. <strong>The histogenesis of glandular neoplasia.</strong> Zajicek G.
  2325. </p>
  2326. © Ray Peat Ph.D. 2007. All Rights Reserved. www.RayPeat.com
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