[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. The definitions of normal and pathological aging are given. The samples of various patterns of aging under the influence of factors accelerating aging (constant illumination or alimentary obesity) or under the factors slowing down aging (treatment with metformin or melatonin) are discussed.

[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.

[A model of resource reallocation during physiological adaptation in Mediterranean fruit fly females]. / Model' pereraspredeleniia resursa v khode fiziologicheskoi adaptatsii samok sredizemnomorskoi fruktovoi mukhi Ceratitis capitata.

Analysis of experimental data on longevity and fertility of females of Mediterranean fruit fly Ceratitis capitata demonstrates that flies lay fewer eggs on the average as the average life-span increases. At the same time, the values of individual life-span and the number of eggs laid are positively correlated. To explain these results, a resource model describing the allocation and reallocation of resources between two basic functions, reproduction and maintenance, was proposed. The reallocation of resources, is triggered by changes in environmental conditions such as diet changes, and the parameters of reallocation depend on the current environmental conditions. Modeling demonstrated that the results of experiments are greatly influenced by population selection and heterogeneity.

[Immune system senescence and mortality dynamics. Role of antigenic load]. / Starenie sistemy immuniteta i dinamika smertnosti. Analiz roli antigennoi nagruzki.

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. Dynamics of immunosenescence is described by mathematical model for age related changes in T-cell populations. Numerical simulation of the model yields estimates for pneumonia severity at different ages. Probability function is used to describe relationship between pneumonia mortality and age related changes in disease severity.

[Mathematical model of the age-related changes in peripheral T cells population]. / Matematicheskaia model' vozrastnykh izmenenii v populiatsii perifericheskikh T-limfotsitov.

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 alterations in immune system led to sharp growth of morbidity and mortality caused by infectious agents. Analysis of the data reveal that key variables of this process are memory and naive T cell concentrations in peripheral lymphoid tissue. The proposed long-time mechanism which hold concentration of T cells in physiological limits are based on assumptions that naive and memory T cells disposed in common niche. The average life-time of memory T cells are varied so that general concentration of T cells holds in normal limits. Numerical experiments demonstrate that average life-time of memory T cells grows with aging, limitation of antigenic load led to considerable grow of resistance in middle age but to little grow in older age. Restriction of thymus involution led to grow of resistance in older age but compensate by diminishing of memory power and longevity. CONCLUSION: The proposal model describe the trade-off between naive and memory T cell subpopulations concentrations and proliferative potentials.

[Significance of quantitative indicators of HBsAg in the pathogenesis and outcome of a malignant form of viral hepatitis B in children]. / Znachenie kolichestvennykh pokazatelei HBsAg v patogeneze virusnogo gepatita B u detei.

The paper is concerned with the time-course of changes in the HBsAg concentration in 31 patients with malignant hepatitis B. No relationship was discovered between the disease outcome and the HBsAg concentration. At the same time in lethal outcomes, the HBsAg concentration dropped significantly more swiftly as compared to that in convalescents. The disease outcome was established to be related to the characteristics such as pregnancy pathology, acute respiratory viral infection, intestinal infections, pyoinflammatory diseases as well as these diseases in combination.

[Endocrine changes in children with acute viral hepatitis]. / Endokrinnye sdvigi u detei s ostrym virusnym gepatitom.

The paper is concerned with the results of hormonal studies on virus hepatitis in 84 children aged 2 to 14, of them 28 had a mild form of disease, 50--medium grave and 6--a severe form of disease. A study was made of the blood content of ACTH, STH, TSH, cortisol, aldosterone, T3, T4, prolactin, and alpha-fetoprotein. The hormones were determined by a radioimmunoassay using Sorin kits (France). A considerable increase in the blood content of ACTH, cortisol, aldosterone and a moderate increase in STH, TSH and T4 concentrations were noted at the height of virus hepatitis. The above changes were interpreted as a result of combined manifestation of a stress reaction and a decrease in the catabolism of some liver hormones. An assumption has been made of a possibility of the effect of late hormonal shifts on the outcome of virus hepatitis of development of chronic hepatitis.