42 Baynes J.W., Dominiczak M.H. Medical Biochemistry. Mosby, 2004, 696 p. Отлично иллюстрированный справочник и учебное пособие. Формат .CHM.
Доступ к данному источнику = Access to the reference.
URL: http://www.tryphonov.ru/tryphonov/serv_r.htm#0          quotation

Figure 42.1 Survival curve and death rate. (A) Mean lifespan is defined as the age at which 50% of a population survives (or has died). The negative slope of the survival curve reaches a maximum at the mean lifespan of a species. (B) The death rate reaches a maximum at the mean lifespan. (C) The age-specific death rate, defined as the number of deaths per time at a given age, e.g. deaths per 100 000 persons of a specific age per year, increases exponentially with age. The lifespan or maximum lifespan potential (MLSP) is defined as the maximum age attainable by a member of the population, which is 120 years for humans. Table 42-1. Decline in biochemical and physiological systems with age. Figure 42.2 Gompertz plots for humans and other species. (A) Humans and other vertebrates; (B) Flies raised at various temperatures (adapted from work of Prof RS Sohal). Figure 42.3 Relationship between DNA repair activity and longevity. Fibroblasts from various species were irradiated briefly, forming thymine dimers and thymine glycol (Chapter 30). The oxidized bases are removed and replaced by excision repair. DNA repair was assessed by the rate of incorporation of a [3H]thymidine tracer into DNA by autoradiography (adapted from Hart RW, Setlow RB: Correlation between deoxyribonucleic acid excision-repair and life-span in a number of mammalian species. Proc Natl Acad Sci USA. 1974;71:2169-2173.) Table 42-2. Age-dependent chemical changes in biomolecules. Figure 42.4 Changes in lens protein and costal cartilage with age. Browning is a characteristic feature of the aging of proteins, not just in the lens, which is exposed to sunlight, but also in tissue collagens throughout the body. Crosslinking of proteins also increases with browning. Crosslinking contributes to the gradual insolubilization of lens protein with age. Aggregates of lens protein disperse light, contributing to the development of 'senile' cataracts. Crosslinking of articular and vascular collagens decreases the resilience of vertebral disks and compliance of the vascular wall with age. These changes in extracellular proteins, shown here for costal collagen, are similar to changes induced by reaction of carbohydrates and lipids with protein during the cooking of foods, a process known as the Maillard or browning reaction. At one level, humans have been described as low temperature ovens, operating at 37°C, with long cooking cycles (?75 years). Many of the Maillard reaction products detected in the crust of bread and pretzels have been identified in human crystallins and collagens, and increase with age. (See also discussion of diabetic complications in Chapter 20.) Figure 42.5 Accumulation of amino acid oxidation products in human skin collagen with age. Methionine is oxidized to methionine sulfoxide (MetSO) by HOCl or H2O2; ortho-tyrosine is a product of hydroxyl radical addition to phenylalanine. Despite a 100-fold difference in their rate of accumulation in collagen, levels of MetSO and o-tyrosine correlate strongly with one another, indicating that multiple ROS contribute to oxidative damage to proteins (adapted from Wells-Knecht MC, et al.: Age-dependent accumulation of ortho-tyrosine and methionine sulfoxide in human skin collagen is not increased in diabetes: evidence against a generalized increase in oxidative stress in diabetes. J Clin Invest 1997;100:839-846.)