[Enhanced control of proliferation in telomerized cells].

Clones of telomerized fibroblasts of adult human skin have earlier been obtained. It was shown that despite their fast growth in mass cultures, these cells poorly form colonies. Conditioned medium, antioxidants, and reduced partial oxygen pressure enhanced their colony formation, but not to the level characteristic of the initial cells. The conditioned medium of telomerized cells enhanced colony formation to a much greater extent than that of the initial cells. A study of proteome of the telomerized fibroblasts has revealed changes in the activities of tens of genes. A general trend consists in weakening and increased lability of the cytoskeleton and in activation of the mechanisms controlling protein degradation. However, these changes are not very pronounced. During the formation of immortal telomerized cells, selection takes place, which appears to determine changes in the expression of some genes. It was proposed that a decrease in the capacity of telomerized cells for colony formation is due to increased requirements of these cells to cell-cell contacts. The rate of cell growth reached that characteristic of mass cultures only in the largest colonies. In this respect, the telomerized fibroblasts resembled stem cells: they are capable of self-maintenance, but "escape" to differentiation in the absence of the corresponding microenvironment (niche), which is represented by other fibroblasts. Non-dividing cells in the test of colony formation should be regarded as differentiated cells, since they have no features of degradation, preserve their viability, actively move, grow, phagocytized debris, etc. It was also shown that telomerization did not prevent differentiation of myoblasts and human neural stem cells. Thus, the results obtained suggest the existence of normal mechanisms underlying the regulation of proliferation in the telomerized cells, which opens possibilities of their use in cell therapy, especially in the case of autotransplantation to senior people, when the cell proliferative potential is markedly reduced and accessibility of stem cells is significantly restricted.

[Specific features of tuberculin sensitivity in children with allergic dermatoses]. / Osobennosti tuberkulinovoi chuvstvitel'nosti u detei s allergodermatozami.

The recent rise in the incidence of allergic diseases, including allergic dermatoses, requires a comprehensive approach to solving a number of problems associated with this disease. Analyzing the case reports of 62 children with allergic dermatoses has indicated that this is a particular contingent of children, which needs a more careful approach to different preventive measures, to interpreting tuberculin reactions and hence to substantiating the use chemotherapeutical prevention. A graded skin tuberculin test and an immunological study should be performed in critical cases.

[Blood and cardiac cholinesterase activity in rats of different sexes and ages during muscle loading and hypokinesia]. / Aktivnost' kholinésteraz krovi i serdtsa krys raznogo pola i vozrasta pri myshechnykh nagruzkakh i gipokinezii.

The activity of acetylcholinesterase (Ache) and butyrilcholinesterase (Bche) in the blood and the heart of 3 and 13-month old control male rats is considerably lower than in female rats. In old rats (25 months) no sex differences in the Ache and Bche were revealed in the heart. In 3 and 13-month old male and female rats, under conditions of muscular exercises, the Ache and Bche activity is lower, and in hypokinetic male rats--higher than that in respective control animals. In all the rats, irrespective of sex, age and motor conditions, the Ache and Bche activity tended to decrease, in direction from the sino-atrial node to the heart apex.

[Retardation of growth and development of rats induced by inhibition of protein synthesis at early postnatal ontogenesis]. / Zaderzhka rosta i razvitiia funktsii krys v rannem vozraste pri ugnetenii belok-sinteziruiushchei sistemy

Treatment of rats with aurantine for 7-30 days reduces the growth and development of animals, and especially of skeletal muscles. Low relative weight of muscles in aurantine-treated animals was accompanied by low resting and action membrane potentials. Incorporation of labelled uridine and lysine into muscles, heart, brain and liver was decreased. Retardation in the growth and development of skeletal muscles resulted into unfavourable shift of the ratio body weight/surface and led to prevalence of catabolic processes over anabolic ones (increased oxygen consumption, heart and respiration rate in experimental animals). These changes are probably related not only to the inhibition of protein synthesis, but to disturbance of regulatory mechanisms, which reveals itself in an increased norepinephrine content of the brain stem and in the increased cholinesterase activity in cardiac pacemaker.

[Mechanisms of the effect of orotic acid on the growth and development of young rats]. / Mekhanizmy vliianiia orotovoi kisloty na rost i razvitie krys rannego vorzrasta

Chronic administration to ratlings of potassium orotate in a dose of 75 mg/kg from the 5th to the 14th day and of 150 mg/kg from the 15th to the 30th day after birth led to a significant acceleration of growth and functional maturation of the animals. The rate of growth in the experimental ratlings was much greater at periods of from the 5th to the 14th and from the 21st to the 30th days than in control animals, but showed no significant difference on the 14th-20th days. Growth acceleration at the period of from the 5th to the 14th days dues to a higher (in comparison with control) activity of the vegetative systems (increased oxygen consumption, frequency of respiration and cardiac contractions at rest). On the 21st-30th days growth acceleration in the experimental animals was associated with an earlier reduction in the activity of the vegetative systems and of the sympathico-adrenal regulation mechanisms, this being pointed to by a fall in catecholamine content in the adrenal glands and the brain.