Rejuvenation is the hypothetical reversal of the aging process Senescence or biological aging is the change in the biology of an organism as it ages after its maturity. Such changes range from those affecting its cells and their function to that of the whole organism. There are a number of theories as to why senescence occurs, including ones that claim it is programmed by gene expression changes and that it.

Rejuvenation is distinct from life extension Life extension, also known as antiaging medicine, experimental gerontology, and biomedical gerontology, refers to attempts to slow down or reverse the processes of aging to extend both the maximum and average lifespan. Some researchers in this area, and "life extensionists" or "longevists" , believe that future breakthroughs in. Life extension strategies often study the causes of aging and try to oppose those causes in order to slow aging. Rejuvenation is the reversal of aging and thus requires a different strategy, namely repair of the damage that is associated with aging or replacement of damaged tissue with new tissue. Rejuvenation can be a means of life extension, but most life extension strategies do not involve rejuvenation.

Historical and Cultural Background

Various myths tell the stories about the quest for rejuvenation. It was believed that magic Magic, sometimes known as sorcery, is the practice of consciousness manipulation and/or autosuggestion to achieve a desired result, usually by techniques described in various conceptual systems. The practice is often influenced by ideas of religion, mysticism, occultism, science, and psychology.[citation needed] or intervention of a supernatural The term supernatural or supranatural pertains to being above or beyond what one holds to be natural. In the case of one who has strong scientific and atheist beliefs, the supernatural is anything unexplainable by natural law or phenomena. While one who holds mystical or heavenly beliefs may have no conception of supernatural phenomena, he or she power can bring back the youth and many mythical adventurers set out on a journey to do that, for themselves, their relatives or some authority that sent them.

An ancient Chinese emperor actually sent out ships of young men and women to find a pearl that would rejuvenate him. This led to a myth among modern Chinese that Japan was founded by these people.

In some religions people were to be rejuvenated after death prior to placing them in heaven In religion, Heaven is the English name for a transcendental realm in which it is believed that people who have died continue to exist in an afterlife. The term "heaven" may refer to the physical heavens, the sky or the seemingly endless expanse of the universe beyond, the traditional literal meaning of the term in English.

The stories continued well into the 16th century. A famous Spanish explorer Juan Ponce de León Juan Ponce de León y Figueroa, was a Spanish explorer. He became the first Governor of Puerto Rico by appointment of the Spanish crown. He led the first European expedition to Florida, which he named. He is associated with the legend of the Fountain of Youth, reputed to be in Florida led the expedition around the Caribbean islands The Caribbean is a region consisting of the Caribbean Sea, its islands , and the surrounding coasts. The region is located southeast of the Gulf of Mexico and Northern America, east of Central America, and to the north of South America and into Florida With an area of 65,758 square miles , it is ranked 22nd in size among the 50 U.S. states. Florida has the most coastline in the Contiguous United States encompassing approximately 1,200 miles. The state has four large urban areas, a number of smaller industrial cities, and many small towns to find the Fountain of Youth The Fountain of Youth is a legendary spring that reputedly restores the youth of anyone who drinks of its waters. Tales of such a fountain have been recounted across the world for thousands of years, appearing in writings by Herodotus, the Alexander romance, and the stories of Prester John. Stories of a similar waters were also evidently prominent. Led by the rumors, the expedition continued the search and many perished. The Fountain was nowhere to be found as locals were unaware of its exact location.

Since the emergence of philosophy Philosophy is the study of general and fundamental problems concerning matters such as existence, knowledge, values, reason, mind, and language. It is distinguished from other ways of addressing fundamental questions by its critical, generally systematic approach and its reliance on rational argument. The word "philosophy" comes from the, sages The wise old man is an archetype as described by Carl Jung, as well as a classic literary figure, and may be seen as a stock character. The wise old man is usually a profound philosopher distinguished for wisdom and sound judgment. These characters usually have beards and self-proclaimed wizards A magician, mage, sorcerer, wizard, or a person known under one of many other possible terms in fiction is someone who uses or practices magic that derives from supernatural or occult sources. Magicians are common figures in works of fantasy, such as fantasy literature and role-playing games; they draw on a history of such people in mythology, always made enormous efforts to find the secret of youth, both for themselves and for their noble patrons Patronage is the support, encouragement, privilege, or financial aid that an organization or individual bestows to another. In the history of art, arts patronage refers to the support that kings or popes have provided to musicians, painters, and sculptors. It can also refer to the right of bestowing offices or church benefices, the business given and sponsors To sponsor something is to support an event, activity, person, or organization financially or through the provision of products or services. A sponsor is the individual or group that provides the support, similar to a benefactor. It was widely believed that some potions A potion is a consumable medicine or poison may restore the youth.

Another commonly cited approach was attempting to transfer the essence In philosophy, essence is the attribute or set of attributes that make an object or substance what it fundamentally is, and which it has by necessity, and without which it loses its identity. Essence is contrasted with accident: a property that the object or substance has contingently, without which the substance can still retain its identity. The of youth from young people to old. Some examples of this approach were sleeping with virgins A virgin originally meant a woman who has never had sexual intercourse. Virginity is the state of being a virgin. It is derived from the Latin virgo, which means "sexually inexperienced woman". As in Latin, the English word is also often used with wider reference, by relaxing the age, gender or sexual criteria. Hence, more mature women or children Biologically, a child is generally a human between the stages of birth and puberty. The legal definition of "child" generally refers to a minor, otherwise known as a person younger than the age of majority. "Child" may also describe a relationship with a parent or authority figure, or signify group membership in a clan, tribe, (sometimes literally sleeping, not necessarily having sex)^[1], bathing in or drinking their blood.

The quest for rejuvenation reached its height with alchemy Alchemy, derived from the Arabic word al-kimia , is both a philosophy and an ancient practice focused on the attempt to change base metals into gold, investigating the preparation of the "elixir of longevity", and achieving ultimate wisdom, involving the improvement of the alchemist as well as the making of several substances described. All around the Europe and also beyond alchemists were looking for the Philosopher's Stone The philosophers' stone sodhi kutta is a legendary alchemical substance, supposedly capable of turning base metals, especially lead, into gold (chrysopoeia); it was also sometimes believed to be an elixir of life, useful for rejuvenation and possibly for achieving immortality. For a long time, it was the most sought-after goal in Western alchemy,, the mythical substance that, as it was believed, could not only turn lead into gold, but also prolong life and restore youth. Although the set goal was not achieved, alchemy paved the way to the scientific method Scientific method refers to a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering observable, empirical and measurable evidence subject to specific principles of reasoning. A scientific method consists of and so to the medical advances of today.

Serge Abrahamovitch Voronoff was a French surgeon born in Russia who gained fame for his technique of grafting monkey testicle tissue on to the testicles of men while working in France in the 1920s and 1930s. This was one of the first medically accepted Rejuvenation Therapy (before he was proved to be wrong around 1930-1940). The technique brought him a great deal of money, although he was already independently wealthy. As his work fell out of favor, he went from being highly respected surgeon to a subject of ridicule. By the early 1930s, over 500 men had been treated in France by his rejuvenation technique, and thousands more around the world, such as in a special clinic set up in Algiers Algiers /ælˈdʒɪərz/ , is the capital and largest city of Algeria and the second largest of the Maghreb after Casablanca. According to the 1998 census, the population of the city proper was 1,519,570 and that of the urban agglomeration was 2,135,630. A recent UN estimate of the urban agglomeration (metropolitan area) puts the population at 3,35.^[2] Noteworthy people who had the surgery included Harold McCormick, chairman of the board of International Harvester Company,^[3] and the aging premier of Turkey Turkey , known officially as the Republic of Turkey ( Türkiye Cumhuriyeti (help·info)), is a Eurasian country situated in the Anatolian peninsula, located in Western Asia, and Eastern Thrace, located in southeastern Europe. Turkey is one of the six independent Turkic states. Turkey is bordered by eight countries: Bulgaria to the northwest;.^[4]

In fiction, there is an increasing amount of work being done on possibilities of rejuvenation treatments, and the effect this would have on society. Misspent Youth as well as the Commonwealth Saga The Commonwealth Saga is a series of science fiction novels by British science fiction writer Peter F. Hamilton. This saga consists of the novels Pandora's Star and Judas Unchained (2005), as well as Misspent Youth (2002). The events of Pandora's Star and Judas Unchained take place 340 years after his single novel Misspent Youth (2002). The by Peter F. Hamilton Peter F. Hamilton is a British science fiction author. He is best known for writing space opera. As of the publication of his tenth novel in 2004, his works had sold over two million copies worldwide are one of the most well known examples of this, dealing with the short and long term effects of a near perfect 80 year old to 20 year old body change with mind intact. Also the Mars trilogy deals with a much more imperfect type of rejuvenation, including problems such as long term memory loss and sheer boredom that comes with such age. Also the post mortal characters in the Revelation Space series often illustrate this issue with long term or essentially infinite lifespans, sheer boredom induces them to undertake activities of extreme risk.

Ancient developments

The dream of longevity is a common heritage of humanity. The ancient researchers and practitioners of Siddha Vaidya in the east had developed strategies for the same reason, which believers in them feel were very effective. Followers of these therapies feel our current understanding of biology, physiology, immunology and biochemistry is helping us to decipher the rationale of these therapies. Ranging from detoxification of the body to targeted nutrition, believers feel these therapies can even produce invivo stimulation and deferentiation of stem cells into useful mature cells. Many of these longevity techniques are still practiced in South India. There is little evidence of their effectiveness.

Modern developments

Aging Ageing or aging (American and Canadian English) is the accumulation of changes in an organism or object over time. Ageing in humans refers to a multidimensional process of physical, psychological, and social change. Some dimensions of ageing grow and expand over time, while others decline. Reaction time, for example, may slow with age, while is an accumulation of damage to macromolecules A macromolecule is a very large molecule most often created by some form of polymerization. In the context of biochemistry, the term may be applied to the four conventional biopolymers , as well as non-polymeric molecules with large molecular mass such as macrocycles. The constituent molecules from which macromolecules are assembled are called, cells The cell is the functional basic unit of life. It was discovered by Robert Hooke and is the functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. Some organisms, such as most bacteria, are unicellular . Other organisms, such as humans,, tissues Tissue is a cellular organizational level intermediate between cells and a complete organism. Hence, a tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues and organs In biology and anatomy, an organ is a collection of tissues joined in structural unit to serve a common function. If any of that damage can be repaired, the result is rejuvenation.

There have been many experiments which have been shown to increase the maximum life span In animal studies, maximum life span is often taken to be the mean life span of the most long-lived 10% of a given cohort. By another definition, however, maximum life span corresponds to the age at which the oldest known member of a species or experimental group has died. Calculation of the maximum life span in the former sense depends upon of laboratory A laboratory is a facility that provides controlled conditions in which scientific research, experiments, and measurement may be performed. The title of laboratory is also used for certain other facilities where the processes or equipment used are similar to those in scientific laboratories. These notably include: animals, thereby achieving life extension Life extension, also known as antiaging medicine, experimental gerontology, and biomedical gerontology, refers to attempts to slow down or reverse the processes of aging to extend both the maximum and average lifespan. Some researchers in this area, and "life extensionists" or "longevists" , believe that future breakthroughs in. A few experimental methods such as replacing hormones A hormone is a chemical released by a cell in one part of the body, that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. It is essentially a chemical messenger that transports a signal from one cell to another. All multicellular organisms produce hormones; to youthful levels have had considerable success in partially rejuvenating laboratory A laboratory is a facility that provides controlled conditions in which scientific research, experiments, and measurement may be performed. The title of laboratory is also used for certain other facilities where the processes or equipment used are similar to those in scientific laboratories. These notably include: animals and humans. There are at least eight important hormones that decline with age: 1. human growth hormone Growth hormone is a protein-based poly-peptide hormone. It stimulates growth and cell reproduction and regeneration in humans and other animals. It is a 191-amino acid, single-chain polypeptide hormone that is synthesized, stored, and secreted by the somatotroph cells within the lateral wings of the anterior pituitary gland. Somatotropin refers to (HGH); 2. the sexual hormones: testosterone or estrogen/progesterone; 3. erithropoietin (EPO Erythropoietin, or its alternatives erythropoetin or erithropoyetin or EPO, is a glycoprotein hormone that controls erythropoiesis, or red blood cell production. It is a cytokine for erythrocyte (red blood cell) precursors in the bone marrow); 4. insulin; 5. DHEA; 6. melatonin; 7. thyroid; 8. pregnenolone. In theory, if all or some of these hormones are replaced, the body will respond to them as it did when it was younger, thus repairing and restoring many body functions.

Most attempts at genetic Genetics , a discipline of biology, is the science of heredity and variation in living organisms. The fact that living things inherit traits from their parents has been used since prehistoric times to improve crop plants and animals through selective breeding. However, the modern science of genetics, which seeks to understand the process of repair have traditionally involved the use of a retrovirus A retrovirus is an RNA virus that is replicated in a host cell via the enzyme reverse transcriptase to produce DNA from its RNA genome. The DNA is then incorporated into the host's genome by an integrase enzyme. The virus thereafter replicates as part of the host cell's DNA. Retroviruses are enveloped viruses that belong to the viral family to insert a new gene A gene is a unit of heredity in a living organism. It is normally a stretch of DNA that codes for a type of protein or for an RNA chain that has a function in the organism. All living things depend on genes, as they specify all proteins and functional RNA chains. Genes hold the information to build and maintain an organism's cells and pass genetic into a random position on a chromosome A chromosome is an organized structure of DNA and protein that is found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions. The word chromosome comes from the Greek χρῶμα. But by attaching zinc fingers (which determine where transcription factors In the field of molecular biology, a transcription factor is a protein that binds to specific DNA sequences, thereby controlling the transfer (or transcription) of genetic information from DNA to mRNA. Transcription factors perform this function alone or with other proteins in a complex, by promoting (as an activator), or blocking (as a repressor) bind) to endonucleases Endonucleases are enzymes that cleave the phosphodiester bond within a polynucleotide chain, in contrast to exonucleases, which cleave phosphodiester bonds at the end of a polynucleotide chain. Restriction endonucleases cleave DNA at specific sites, and are divided into three categories, Type I, Type II, and Type III, according to their mechanism (which break DNA Deoxyribonucleic acid ( /diːˌɒksɨˌraɪbɵ.nuːˈkleɪ.ɪk ˈæsɪd/ (help·info)) (DNA) is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses. The main role of DNA molecules is the long-term storage of information. DNA is often compared to a set of strands) homologous recombination Homologous recombination, also known as general recombination, is a type of genetic recombination used in all forms of life in which nucleotide sequences are exchanged between two similar or identical strands of DNA. The process involves several steps of physical breaking and the eventual rejoining of DNA. This process is most widely used to can be induced to correct and replace defective (or undesired) DNA sequences. The first applications of this technology are to isolate stem cells Stem cells are cells found in all multi cellular organisms. They are characterized by the ability to renew themselves through mitotic cell division and differentiate into a diverse range of specialized cell types. Research in the stem cell field grew out of findings by Canadian scientists Ernest A. McCulloch and James E. Till in the 1960s. The two from the bone marrow Bone marrow is the flexible tissue found in the hollow interior of bones. In adults, marrow in large bones produces new blood cells. It constitutes 4% of total body weight, i.e. approximately 2.6 kg in adults of patients having blood Blood is a specialized bodily fluid that delivers necessary substances to the body's cells – such as nutrients and oxygen – and transports waste products away from those same cells disease mutations Mutations are changes in the DNA sequence of a cell's genome and are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that occur during meiosis or DNA replication. They can also be induced by the organism itself, by cellular processes such as hypermutation, to correct those mutations in laboratory dishes A Petri dish is a shallow glass or plastic cylindrical lidded dish that biologists use to culture cells. It was named after German bacteriologist Julius Richard Petri, who invented it when working as an assistant to Robert Koch. Glass Petri dishes can be reused by sterilization (for example, in an autoclave or by dry heating in a hot air oven at 16 using zinc finger endonucleases and to transplant the stem cells back into the patients ^[5].

Regenerative medicine uses three different strategies:

1. Implantation of stem cells from culture into an existing tissue structure
2. Implantation of stem cells into a tissue scaffold that guides restoration or
3. Induction of residual cells of a tissue structure to regenerate the necessary body part.

A salamander can not only regenerate a limb, but can regenerate the lens or retina of an eye and can regenerate an intestine. For regeneration the salamander tissues form a blastema by de-differentiation of mesenchymal cells, and the blastema functions as a self-organizing system to regenerate the limb ^[6].

Yet another option involves cosmetic changes to the individual to create the appearance of youth. These are generally superficial and do little to make the person healthier or live longer, but the real improvement in a person's appearance may elevate their mood and have positive side effects normally correlated with happiness. Cosmetic surgery is a large industry offering treatments such as removal of wrinkles ("face lift"), removal of extra fat (liposuction) and reshaping or augmentation of various body parts (abdomen, breasts, face).

There are also, as always in history, many fake rejuvenation products that do not work. Chief among these are powders and sprays and gels and homeopathic that claim to be "growth hormone". Authentic growth hormone can only be injected, because the 191 amino-acid protein is too large to be absorbed through the mucous membranes, and would break up in the stomach if it is swallowed.

Strategies for Engineered Negligible Senescence (SENS)

The leading modern exponent of scientific rejuvenation is the biomedical gerontologist Dr. Aubrey de Grey. He calls his project to reverse the damage we call aging "SENS" (Strategies for Engineered Negligible Senescence). He has proposed seven strategies for what he calls the "seven deadly sins":^[7]

1. Cell loss can be repaired (reversed) just by suitable exercise in the case of muscle. For other tissues it needs various growth factors to stimulate cell division, or in some cases it needs stem cells.
2. Senescent cells, can be removed by activating the immune system against them. Or they can be destroyed by gene therapy to introduce "suicide genes" that only kill senescent cells.
3. Protein cross-linking can largely be reversed by drugs that break the links. But to break some of the cross-links we may need to develop enzymatic methods.
4. Extracellular garbage (like amyloid) can be eliminated by vaccination that gets immune cells to "eat" the garbage.
5. For intracellular junk we need to introduce new enzymes, possibly enzymes from soil bacteria, that can degrade the junk (lipofuscin) that our own natural enzymes cannot degrade.
6. For mitochondrial mutations the plan is not to repair them but to prevent harm from the mutations by putting suitably modified copies of the mitochondrial genes into the cell nucleus by gene therapy. The mitochondrial DNA experiences a high degree of mutagenic damage because most free radicals are generated in the mitochondria. A copy of the mitochondrial DNA located in the nucleus will be better protected from free radicals, and there will be better DNA repair when damage occurs. All mitochondrial proteins would then be imported into the mitochondria.
7. For cancer (the most lethal consequence of mutations) the strategy is to use gene therapy to delete the genes for telomerase and to eliminate telomerase-independent mechanisms of turning normal cells into "immortal" cancer cells. To compensate for the loss of telomerase in stem cells we would introduce new stem cells every decade or so.

Dr. de Grey has created the Methuselah Mouse Prize, which awards money to researchers who can rejuvenate mice.

Scientific Journal

• Rejuvenation Research Editor: Aubrey de Grey. Publisher: Mary Ann Liebert, Inc. ISSN 1549-1684 - Published Quarterly.

See also

• Photorejuvenation
• American Academy of Anti-Aging Medicine
• Biogerontology
• Biological immortality
• DNA repair
• DNA damage theory of aging
• Eternal youth
• Facial rejuvenation
• Fountain of Youth
• Hayflick
• Hayflick limit
• Immortality
• Indefinite lifespan
• Life extension
• Nanomedicine
• SAGE KE
• Senescence
• Shunamitism
• Telomere
• Telomerase
• Tissue engineering
• Therapeutic cloning

References

1. ^ Steven Shapin and Christopher Martyn, “How to live forever: lessons of history”, British Medical Journal, BMJ 2000;321;1580-1582
2. ^ Common, Laura. (April 25, 2000) The Medical Post [1] Great balls of fire: from prehistory, men have tried implants and extracts from macho animals to cure impotence, but it was only relatively recently that they began to understand why they did so.
3. ^ Grossman, Ron. (March 31, 1985) Chicago Tribune Lost lake shore drive: Mourning an era; Mansions of rich and famous yield to giant condos. Section: Real estate; Page 1.
4. ^ Jones, David. (December 11, 1986) The Times Christmas Books: Believe it or not - Adam and Eve to bent spoons / Review of books on beliefs.
5. ^ Jocelyn Kaiser (2005). "Gene therapy. Putting the fingers on gene repair". SCIENCE 310 (5756): 1894–1896. doi:10.1126/science.310.5756.1894. PMID 16373552.
6. ^ Brockes JP, Kumar A (2005). "Appendage regeneration in adult vertebrates and implications for regenerative medicine". SCIENCE 310 (5756): 1919–1923. doi:10.1126/science.1115200. PMID 16373567.
7. ^ de Grey, Aubrey; & Rae, Michael (September 2007). Ending Aging: The Rejuvenation Breakthroughs that Could Reverse Human Aging in Our Lifetime. New York, NY: St. Martin's Press. pp. 416. ISBN 0312367066.

External links

• Regenerative Medicine and Rejuvenation
• Life Extension magazine interview about rejuvenation science
• Resources and Articles on the Biology of Aging and Life-Extension
• The Biogerontology Research Foundation - a UK-based charity focused on rejuvenation research
• Aging Cell - an online publication covering the novel rejuvenation mechanisms

Categories: Aging | Gerontology | Life extension | Transhumanism | Demography | Concepts in alternative medicine

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