Reversible C-C bond formation in group 4 metal complexes: nitrile extrusion β-aryl elimination.

Pyridylamides of zirconium and hafnium with [C,N,N]-ligands reversibly insert nitriles into M-C bonds leading to an observable equilibrium between the starting [C,N,N]-complexes and newly formed [N,N,N]-complexes with a ketimide moiety in a 7-membered metallacycle. The discovered reversible insertion of nitriles into M-C bonds represents an unprecedented example of β-aryl elimination from a ketimide ligand in early transition metal complexes. Experimental and computational studies suggest thermodynamic and electronic reasons for this reactivity.

[The hyperiricosuria as an indicator of derangement of biologic functions of endoecology and adaptation, biologic reactions of excretion, inflammation and arterial tension].

During millions years in all animals allantoine (oxidized by uricase uric acid) was catabolite of purines and ascorbic acid was an acceptor of active forms of oxygen. The proximal tubules of nephron reabsorbed the trace amounts of uric acid Then during phylogenesis the primates had a mutation of ascorbic acid gen minus. Later on occurred a second spontaneous mutation and uricase gen minus and uric acid became catabolites of purines.

[Basic principles of creation of multilevel multistage mathematical model of aging].

Current knowledge on the aging allows to elaborate approaches to the creation of multilevel model of multistage of human aging taking into consideration events during the aging at various levels of integration: molecular, cellular, tissue, organ, systemic, organism. The present paper have deals with main states of the mathematical model of multistage aging, principles of its construction, applicability and evaluation of its prognostic power. There are 3 levels of integrative systems: homeostatic (organismal), systemic and cellular-molecular.

[Investigation of disability prevalence in men and women of advanced age].

Disability prevalence among men and women are investigated using NLTCS surveys conducted in 1982, 1984, 1989, 1994 and 1999 in the US population, on persons older than 65 years, and data from LSADT surveys conducted in 1995, 1997, 1999 and 2001 in the population of the Danish Twins Registry, on persons older than 75 years. In both surveys women are more disabled than men. The probability of becoming disabled and surviving is higher for women than men.

[Signal (nondestructive) role of environment in aging].

Adequate pattern of gene activity due to positive environmental influences of natural niches can enhance the resistance of organisms and reduce their aging. But the life expectancy in nature is much below (due to high external mortality) than in laboratory conditions. Some mutated genes, modified products of which are involved in regulatory control circuits, can (in some cases) mistakenly transform inadequate external cues of artificial experimental conditions to the regular reaction of an organism on the quite natural environment.

[Gerontology in silico: the emergence of a new discipline].

In this paper the modern views concerning the place of mathematical and computer modeling of aging and aging related pathologies in the current state and in future developments of gerontology are discussed. The review of most perspective directions of research including analyses of demographic, molecular, cellular, and physiological mechanisms of aging, the roles of damage and reparation of DNA, cell proliferation and apoptosis, where application of mathematical modeling is promising is given. Special attention is paid to the results and perspectives of mathematical modeling in experimental gerontology including modeling of aging and longevity in laboratory animals (nematode worms, fruit flies, mice, rats) and humans.

[Effect of epitalon and melatonin on life span and spontaneous carcinogenesis in senescence accelerated mice (SAM)].

Female senescence accelerated mice SAMP-1. (prone) and SAMR-1 (resistant) were exposed 5 times a week monthly to melatonin (with drinking water 20mg/ml during the night hours) or to s.c.

[Effect of light deprivation on homeostasis, life span and development of spontaneous tumors in HER-2/neu transgenic mice].

Twenty five female HER-2/neu transgenic mice (FVB/N), aged 2 months, were surgically deprived of lighting; 30 intact transgenic mice, kept under standard conditions, were in control. Light deprivation was followed by inhibited intake of feed, decreased body mass and delayed age-associated estral disorders, as compared with control. Mean survival rate among experimental mice was higher by 13.

[Serotonin transporter gene polymorphism and factors influencing mental and physical health in aging].

Genetic predisposition is thought to exert a certain influence on the indices related to longevity and quality of life. Many of the indices, namely cognitive functioning, stress resistance, metabolism control, may be related to serotonin activity. To study polymorphic serotonin transporter gene variants and their association with features relevant for survival and longevity prognosis, a sample of elderly Russians from Moscow community recruited in the project "Stress-related mechanisms in Russia", comprising 196 subjects, mean age 76.

[Mathematical modeling in gerontology--strategic perspectives].

Mathematical description of aging and mortality is presented. A review of tendencies in modeling is discussed and some difficulties related to adequacy and the ways of information presentation in the models are talked about. A short view is given at the two main modeling techniques in biology, namely the models of data and models of a system.

[Immune system senescence and mortality dynamics. Role of antigenic load].

This paper is dedicated to investigation of the impact of total antigenic load on immunosenescence. Data on pneumonia mortality have been simulated. The results of modelling revealed that antigenic load as well as probability of infecting could account for the shifting in mortality that takes place for different countries.

[Problems in using methods of analyzing gene expression in studying the aging process].

Aging processes are now actively investigated on the base of analysis of changes in gene expression. Many of the standard methods (such as hierarchic clustering, method of K-means, SOM (Self-organizing maps), Gene Shaving, etc.) do not take into account the specifics of time sets.

[Problems of the existence of "optimal" function survival functions in experiments of varying protein supplies to Mediterranean fruit flies].

The paper is devoted to the discussion of the possibility of analyzing the changes in survival curves of Mediterranean Fruit Flies under different levels of reproduction by means of solving the optimization problem with some objective function. The investigation is carried out on the base of mathematical model with approximations resulting in the analysis of joint changes in survival functions and reproduction in flies subjected to different conditions of protein availability in food. The model describes possible mechanisms of evolutionary selection from the point of view of trade-off in average life span and reproduction.

[Mathematical modeling and simulation of life history and tradeoffs].

General trends in mathematical life history modeling are reviewed. In modern experimental biogerontology life history consists of all traits that affect fecundity and survival. Tradeoffs are of special importance in the theory of life history, studied either as an evolutionary phenomenon or as a feature of individual life history.

[Mathematical model of the age-related changes in peripheral T cells population].

Unlabelled: An analysis is presented of the data concerning to the decline with the age the human immune system function. The most prominent changes links with T-cellular immunity. The embrace the naive T cells generation rate diminishing, peripheral lymphoid tissue volume shrinkage, absolute and relative concentration of naive T cells in blood decreasing, average length of T cell telomers reducing.

[The organization of care for burn victims in catastrophes].

The experience in medical care and treatment of burned patients showed that adequate anti-shock infusion therapy can be established only 4-6 hours after the sustained trauma. However, even despite such a delay, many burned patients (75-80%) get well, due to the later adequate complex treatment controlled by experienced burn specialists [correction of combustiologists] in hospital units specially organized and equipped for this category of patients. Within the first 2-4 days after the trauma, it is recommended to distribute major accident victims between different specialized burn units, using specially equipped air and motor transportation vehicles.