Volume 6, Nº 4 (2016)

Telomerase is a ribonucleoprotein enzyme that elongates telomeres and therefore maintains chromosomal stability in germ lines, as well as in the majority of cancer cells during cell doubling. However, up to 30% of human tumors of different types do not express telomerase but instead use an alternative lengthening of telomeres (ALT). Here we show that human tumor-derived ALT cell lines express a LINE-1 (L1) retrotransposon. This indicates its participation in telomere maintenance, possibly, by a slippage mechanism during telomeric DNA synthesis. Moreover, the suppression of L1-encoded reverse transcriptase activity by antisense strategy or treatment of ALT cells with reverse transcriptase inhibitor 3'-azido-2',3'-dideoxythymidine (AZT) induces progressive telomere shortening, arrest in G2 phase of the cell cycle, and, eventually, cancer cell death. This finding suggests a unique opportunity to cure cancer in a number of cases.

Numerous and rather contradictory research data demonstrate that the mechanism of increased susceptibility to diseases in old age so far has no satisfactory explanation. Concurrently, the relevant literature almost lacks any comparative data on the specific features on the effect of surgeries and traumas on the structure and function of lymphoid organs in patients of different age cohorts. However, lymph nodes mark the activity of local inflammation, and changes in them allow the estimation of treatment efficiency, as well as the prognosis and prevention of many complications. This is especially important with the constant increase in the average age and life expectancy in the human population and the more active use of surgeries in elder and old patients.

Calbindin 28 kDa (CB), calretinin (CR), and parvalbumin (PB) are calcium-binding proteins that are widely distributed in the nervous system and selectively expressed in certain population of neurons. These proteins are expressed not only in the central nervous system but also the autonomic ganglia. CB and PB are found in the sympathetic ganglia of rodents, and CB and CR are found in metasympathetic intramural ganglia. Their functions are poorly understood, but one can suggest that they have an important role in the regulation of Ca²⁺ levels in the cell. Calcium-binding proteins also play an important role in the age-related development of autonomic neurons. The percentage of CB- and CR-immunopositive neurons in the metasympathetic intramural ganglia of the small intestine in early postnatal development increases, whereas the percentage of CB decreases in sympathetic ganglia. It is possible that the functional meaning of such changes may be associated with the role of calcium currents in the development of neurons and the synaptic transmission.

Among the most common complications of type 2 diabetes mellitus (DM2) are disorders of the cardiovascular and the thyroid systems. The functions of these systems may be weakened with increasing age. However, the mechanisms of these disorders, including the role of alterations in the adenylyl cyclase signaling system (ACSS), are not fully elucidated. The objective was to study the thyroid status and ACSS activity of the myocardium and the thyroid gland (TG) of rats with 8- and 18-month DM2 (DM-8 and DM-18) as compared to control animals of the same age (C-8 and C-18). In the myocardium of rats with DM2, an imbalance of β-adrenergic regulation of ACSS was detected, and these disturbances were amplified with increasing age. In the myocardium of rats of the C-18 group, disturbances of ACSS hormonal regulation were also identified but they were less pronounced. In diabetic rats, the levels of free thyroxine and total triiodothyronine decreased, the level of thyroid stimulating hormone (TSH) increased, and the stimulatory effect of TSH on the ACSS in TG was attenuated, which indicates the hypothyroid state in long-term DM2. In the C-18 group, these changes were absent. Thus, in the myocardium and TG of rats with 18-month DM2, the hormonal regulation of ACSS was violated, which may be one of the causes of cardiovascular pathology and hypothyroid states in long-term DM2.

In this paper, we investigated the dynamics of aging of the estrous function of female rats kept in the conditions of standard vivarium lighting that received luzindolee—a blocker of melatonin receptors. Every three months, daily, for two weeks, vaginal smears were taken from the animals and a cytological examination of the vaginal contents was conducted. Despite the difference in the mechanisms of the development of melatonin system failure (a decreased production of melatonin and a blockade of melatonin receptors), the effects of the influence on the ovulatory function are similar. With a blockade of melatonin receptors, an appearance of premature signs of aging of the reproductive function in rats was observed. It was manifested by an increased duration of the ovulatory cycle; a decrease in the number of regular cycles; the emergence of irregular cycles; a decrease in the number of short estrous cycles and an increase of long cycles; and the early development of persistent estrus.

An assessment of the physical status of older women was performed based on anthropometry and bioelecytrical impedance analysis. The somatotype was determined with the use of J. Tanner’s index of sexual dimorphism (1951). In the surveyed sample, 46.15% women had a gynecomorphic body type manifested in the structural feminization of the skeletal system; masculinization of the skeletal system (andromorphism) was found in 4.74% of cases; and mild dysplasia towards the opposite sex was observed in 49.11% of older women, which corresponded to the mesomorphic somatotype. It was found that women with a gynecomorphic body type were significantly shorter than those with mesomorphic or andromorphic types; they had lower mass and transverse dimensions of the body. The largest absolute content of the fat mass and lean mass components were found in women with andromorphic body type, while the representatives of the sample with a gynecomorphic body type demonstrated the lowest values of these indicators of body composition. The results of anthropometric and bioimpedance measurements with allowance for the body type of elderly women involving J. Tanner’s index of sexual dimorphism reflect their adaptive capabilities and can serve as markers (predictors) of nonspecific somatic diseases.

Assessment of the quality of life in male inhabitants of the European Russian North revealed decreased indices of the physical health component (the scale of role functioning determined by physical condition) and mental health component (the scales of social-role functioning and role functioning determined by emotional state and mental health) as compared to the inhabitants of Siberia as a control (comparison) group. Men aged under 29 had the highest scores at all scales. The scores decreased with age. The greatest reduction was observed for the scales of general well-being and bodily pain. There was a moderate decrease for the scales of physical functioning, role functioning determined by emotional state, and role functioning determined by physical condition. Quality of life was closely related to the northerners’ self-rated health, pathology index, molecular marker of aging, and biological age. A negative correlation between these values implies deterioration in the physical and mental health with biological age. The quality of life for the northerners also correlated with their hormonal status. There was a relationship between testosterone and three scales of physical health components, i.e., between cortisol and one scale of physical component and between both dehydroepiandrosterone sulfate and insulin and the scales of physical and mental components of health. The effect of various hormones on different age groups of northerners was demonstrated.