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Biomedical subjects

C B Olson

Publications and source records attributed to C B Olson.

11 recordsLinked to original sources
PubMed1988

A possible cure for death.

Chemical preservation of the brain may prevent death. Life for an individual human being is inextricably linked to the existence of his or her mind. It is widely accepted that the mind is a product of the functioning of the brain, which, according to this view, is nothing more and nothing less than a fantastically complicated machine. Chemical preservation of the brain (promptly after the cessation of vital functions) preserves not only the neuronal configuration but also a great deal of molecular structure. Thus, it is plausible that a chemopreserved brain contains within it the information of the design of the "brain machine". If so, then technology of the distant future may be able to extract that information and construct a new functionally identical brain machine (as well as a body), thereby allowing the corresponding individual to wake up and live again. It is argued that one's identity is defined by what the brain does rather than how it does it or what it does it with, and therefore that replacement of one's brain with a functionally identical machine does not affect one's identity. Some advantages of chemopreservation relative to cryopreservation as a possible means of preventing death are discussed.

Animals↗
PubMed1987

A review of why and how we age: a defense of multifactorial aging.

Part 1: Longevity is optimized such that reproduction is maximized. Williams (Evolution, 11 (1957) 398-411) proposed pleiotropic genes with beneficial effects during youth and harmful effects at older ages. Because of environmental death (e.g. predation, disease, accidents), even a small increase in younger reproduction could outweigh a large harmful effect at older ages. Guthrie (Perspect. Biol. Med., 12 (1969) 313-324) and Kirkwood (Nature, 270 (1977) 301-304; New Sci., 81 (1979) 1040-1042; Physiological Ecology: An Evolutionary Approach, Blackwell, Oxford, 1981, pp. 165-189; Hum. Genet., 60 (1982) 101-121; Proc. R. Soc. Lond., B205 (1979) 531-546; Handbook of the Biology of Aging, 2nd Edn., Von Nostrand Reinhold New York, 1985, pp. 27-44) proposed that additional longevity requires a further investment of resources when young, thereby reducing the resources available for reproduction when young. The gene(s) controlling this partitioning of resources between younger and older reproduction are a good example of Williams's pleiotropic genes. Population biology provides a great deal of evidence of a tradeoff between younger and older reproduction. A "marginal longevity theorem" is proposed which states that for a population in equilibrium with its environment a marginal change in any gene affecting longevity should cause equal and opposite marginal changes in younger and older expected reproduction. Senescence is not irrelevant in the wild; rather, the amount of senescence in the wild results from a balance between its marginal costs to older reproduction and its associated marginal benefits in younger reproduction. Part 2: The wide variety of damage prevention processes in the body are subject to the problem of diminishing returns. Consequently, a broad spectrum of damage occurs in the body, varying in frequency, harmfulness, and ease of repair. The types of damage which are prevented or repaired tend to be more frequent, harmful, and easily prevented or repaired. In contrast, aging damage (which accumulates) consists of a large number of different types of damage which (when considered separately) are relatively infrequent, less harmful, and/or more difficult to repair. Only when these types of damage accumulate to become very numerous do they (when considered collectively) become significant. Since the selective advantages associated with senescence apply to all parts of the body, primary aging damage occurs in all tissues, cells, and subcellular organelles. The distribution of metabolic resources among the various damage repair and prevention processes is optimized.(ABSTRACT TRUNCATED AT 400 WORDS)

Aging↗
PubMed1985

Isolation and characterization of deoxyribonucleic acid from tissue of the woolly mammoth, Mammuthus primigenius.

DNA was isolated from tissue samples of several mammoth specimens, radiocarbon dated between 10,000 and 53,000 years old. The DNA was purified by chromatography on hydroxyapatite at 60 degrees C and was characterized as a heterogeneous population of fragments ranging in size from 3000 to 200 base pairs. Thermal denaturation analysis demonstrated that approximately 25% of the DNA had a base composition similar to Asian elephant DNA calculated as 36% G + C. Preliminary analysis by nucleic acid hybridization indicated that only a small fraction of DNA isolated from mammoth tissue (2-5%) was homologous to DNA of Asian elephant, a close living relative of the mammoth. Our results provide the first definitive isolation and characterization of DNA from ancient tissue and suggest a purification strategy that will lead to preparations of DNA from mammoth tissue significantly enriched in elephant-related DNA sequences.

Animals↗
PubMed1981

A theory of the origin of life.

Life on Earth is essentially nucleic acids (NAs) influencing peptide synthesis such that NA replication is favored. It is proposed that the ability to synthesize polypeptides evolved gradually - one peptide bond at a time. The proposed evolution of the peptide synthesis apparatus begins with a 'transfer NA' (tNA) which catalyzes the transfer of activated amino acids to accessible amino groups in its environment. The resulting 'capped molecules' (with single amino acid 'caps') in turn favor NA replication. The proposed evolution of the peptide synthesis apparatus from the tNA onward is characterized by a progressive increase in the number of amino acids per cap: two tNAs jointly produce a 'dipeptide cap', three tNAs jointly produce a 'tripeptide cap', etc. Messenger NAs evolve because they can specify the composition and sequence order of the peptide caps. Lastly, ribosomal NAs evolve. The origin, expansion, and standardization of the genetic code are discussed. It is proposed that the presence triplet code evolved by a process of codon length refinement, and the originally codons of varying lengths were allowable, as were unassigned bases between codons. An environmental supply of activated compounds for early evolving entities is proposed. An 'environmental retention and redistribution process' is proposed to have acted as a functional substitute for the cell wall and cell division of early evolving entities.

Amino Acids↗
PubMed1973

Effects of caffeine and isoprenaline on mammalian ventricular muscle.

1. Caffeine, 0.6-20.0 mM, altered the duration of the action potential recorded from kitten papillary muscles; low concentrations shortened and high concentrations prolonged the action potential.2. Caffeine, 20 mM, prolonged the action potential by delaying the final phase of repolarization.3. Caffeine, 2.0-20.0 mM increased the tension developed and the duration of the isometric contraction.4. When large stimulating electrodes were used, all concentrations of caffeine increased the duration of the action potential; this effect was probably due to the interactions of caffeine and released endogenous catecholamines.5. Concentrations of caffeine and isoprenaline, which separately caused little change in the duration of the action potential, greatly prolonged the action potential when used together.6. The effects of caffeine may be due to an increase in membrane calcium current in addition to an action on intracellular calcium stores.

Action Potentials↗
PubMed1968

Temporal relation between long-lasting aftercontractions and action potentials in cat papillary muscles.

Sotalol, an adrenergic-blocking and antiarrhythmic agent, increases markedly and simultaneously the duration of both action potentials and contractions in papillary muscles. The active tension is manifested as a main twitch contraction followed by a maintained low level of residual tension (aftercontraction) which persists until the terminal phase of rapid repolarization. The Strength of the aftercontraction is augmented when the extracellular concentration of calcium is increased.

Action Potentials↗