[Circadian rhythm of skin temperature of children during puberty].

Results of long-term research of becoming circadian rhythm of temperature (CRT) of human skin of shoulder during puberty are presented. For this purpose, 48-hour monitoring T at children, teenagers and mature young men and female from 8 till 22-th years with application of a method "Thermochron iButton" has been led. Age dynamics of mesor, reflecting process of becoming thermoregulation of organism during puberty, has wave character. The first wave with maximum T was observed at children of 10-11 years, second maximum T--at teenagers of 14-15 years. And at persons man's and female dynamics of mesor is synchronous, however, at girls from 8 till 17 years mesor authentically above. At adult people mesoris above at young men. Dynamics of amplitude CRT does not vary till 12-13 years, in 14-15 years at boys the size of amplitude decreases, and at girls increases. In 16-17 years at children amplitude sharply increases with the subsequent significant decrease by the period of a maturity (20-22 years). At boys, amplitude of CRT it is authentic more, than at girls, at adult people this parameter does not differ. At research of a cycle a dream-wakefulness periods in which changes daily thermoregulation are revealed: at boys in the age of 10-11 years, and at girls at 10-11 and in 16-17 years. During these periods T at night is above, than in the afternoon.

[Change in short-term memory in pupils of 5-7th classes in the process of class work].

The subject of this study was the investigation of the short-term memory (STM) of visual (SVM) and auditory (SAM) modality in boys and girls of the middle school age, as in the daytime, and during the course of the school week. The obtained data show that in pupils from the 5th to the 7th class SVM and SAM playback volume in children of both genders is significantly increased, while SVM productivity in boys from 6 - 7th classes is higher than in girls of the same age. The amplitude of day changes in SVM and SAM was found to decrease significantly with the age. In all age groups the range of daily fluctuations in short-term memory of both modalities in boys appears to be higher than in girls. In all age groups a significant part of schoolchildren was revealed to possess optimal forms of temporal organization of short-term memory: morning, day and morning-day types, in that while during the school week in pupils of 5th to 7th classes of both genders the number of optimal waveforms of curves of daily dynamics of short-term memory increases, which contributes to the optimization of their mental performance.

Ultradian biorhythms of cell proliferation.

We studied circadian and ultradian rhythms of mitotic index of epithelial cells of the esophagus, intestine, and dorsal surface of the tongue, and thymocytes from mice maintained at normal and inverted light regimens. It was shown that in normal animals, the period of ultradian oscillations was shorter during the active circadian phase compared to the passive phase. Photoinversion changed the correlation between ultradian oscillations of the mitotic index and its circadian phases, which was differently pronounced in various tissues. Thus, changes in daily illumination serve as the time indicator for circadian rhythms of cell proliferation, but not for ultradian oscillations of mitotic activity.

[Changes in short-term memory in young schoolchildren during studies]. / Izmeneniia kratkosrochnoi pamiati u detei mladshego shkol'nogo vozrasta v protsesse uchebnoi deiatel'nosti.

Daily variations in short-term visual and hearing memory were found in 8-10-year-old children. It was ascertained that they were not optimized with the learning time in most children. In 70% of the children, individual daily variations in short-term memory of all modalities were asynchronous. In these children, the mean daily volume of short-term hearing memory was much more than that of short-term visual one. The girls could reproduce the greater volume of visual information than could be boys.

[IgM, IgG and IgG subclass antibodies to herpes simplex virus in persons of different ages]. / antitela k virusu prostogo gerpesa, otnosiashchiesia k IgM, IgG i podklassam IgG, u lits raznogo vozrasta.

IgM, IgG antibodies to herpes simplex virus and their subclases were investigated in 565 subjects of different age tested at virological laboratories of St. Petersburg in 1996-1997. The majority of these subjects had a history of herpes infection and 21.5% had IgM antibodies to herpes simplex virus (HSV), marker of acute herpetic infection. Besides IgM, IgG1 antibodies can be referred to early antibodies appearing during the acute stage of herpetic infection. The predominant subclass was HSV IgG3 antibodies. As for IgG4, they were completely absent in infants aged under 1 year, were detected in 6.2% children aged under 14 years, and were present in 12.2-12.5% adults.

[Circadian rhythm of reaction of epithelial cells of the tongue and esophagus to the effects of hydroxyurea]. / Sutochnyi ritm reaktsii kletok épiteliia iazyka i pishchevoda myshei na vozdeistvie oksimocheviny.

A study was made of the effect of a single injection of hydroxyurea (HU) on the daily rhythm of labelling index (LI) in the epithelial cells of the tongue and esophagus. HU was injected 6 times a day. The degree of decrease in the LI at varying times of the day correlated well with the initial level of the LI. At the same time the number of sensitive cells changed thought the day in a different proportion than LI rhythm, the fact suggesting the independence of these rhythms.

[Cell population relations in the mechanism of the circadian rhythm of proliferative activity in the tongue epithelium of mice exposed to continuous light]. / Kletochno-populiatsionnye vzaimootnosheniia v mekhanizmakh sutochnogo ritma proliferativnoi aktivnosti v épitelii iazyka myshei, soderzhavshikhsia pri postoiannom osveshchenii.

A single dose of 3H-thymidine was injected to mice maintained either on a 12-hour light-dark cycle (LD group) or on a long-term continuous light (LL group) at the peak of DNA synthetic activity in the tongue epithelium. The parameters of the circadian rhythm of cell division and mitotic cycle were studied. The LL group animals demonstrated pronounced asynchronization of the circadian rhythm of the mitotic index. At the same time the curves of the percentage of labeled cell populations in the LD and LL group animals appeared similar. The data suggest that asynchronization of the circadian rhythm of the mitotic index is linked with cell-population interrelations and the differences in the status of individual cell populations entering the mitotic cycle at varying times of the day.

[Diurnal rhythm of the sensitivity of proliferating epithelial cells of the tongue and esophagus to adrenaline]. / Sutochnyi ritm chuvstvitel'nosti proliferiruiushchikh kletok épiteliia iazyka i pishchevoda k adrenalinu.

A study was made of the effect of a single injection of various doses of adrenaline on cell division in the epithelium of the tongue and esophagus. The hormone was injected 6 times a day. The animals were sacrificed after 40 and 60 min. A direct correlation between the adrenaline dose and its antimitotic action was revealed. The degree of a decrease in the mitotic index at varying times of the day correlated well with the initial level of the mitotic number in the epithelium. At the same time the number of adrenaline-sensitive cells changed throughout the day in a different proportion than mitotic rhythms, the fact suggesting the existence of the cell-population mechanisms by which mitotic rhythms are controlled.

[Cell kinetics in the mouse esophageal epithelium in relation to the time of day]. / Kinetika kletok épiteliia pishchevoda myshei v zavisimosti ot vremeni sutok.

The kinetics of mouse esophageal epithelial cells was investigated throughout 90 h after a single injection of 3H-thymidine at 01 or at 13 h--the times of the peak and minimal magnitudes of the radioisotope index in the circadian rhythm of proliferation. The mitotic cycle parameters in the cells varied but insignificantly. For cells treated with 3H-thymidine at 01 h, T = 24.3 h, ts = 6 h, tG2 min = 1.5 h, tG2+ 1/2 M = 2.9 h and tG1+/2 M = 15.4 h; for those treated with 3H-thymidine at 13 h, T = 25.6 h, ts = 8.4 h, tG2 min = 1 h, tG2+ 1/2 M = 2.2 h, tG1+ 1/2 M = 15 h. Cells labeled at 01 h proliferated more actively for a long period of time as compared to those labeled at 13 h. The synchronism in undergoing several successive mitotic cycles was greater for cells labeled at the peak radioisotope index. The data obtained also suggest that the majority of cells enter the G0 phase after the completion of the first cycle. The duration of the G0 phase varies in different cell populations.

[Participation of different cell populations in the mouse esophageal epithelium in the formation of a circadian rhythm of proliferation]. / Uchastie razlichnykh populiatsii kletok épiteliia pishchevoda myshei v formirovanii sutochnogo ritma proliferatsii.

Investigation of the variations in the index of labeled mitoses throughout 90 hours after a single injection to mice of 3H-thymidine at 01 or at 13 o'clock (the periods of the maximal and minimal labeling index in the circadian rhythm of cell proliferation) showed that the cell population which had completed synchronously the mitotic cycle during the first day of experiment also plays the main role in the formation of the peak rhythms in the mitotic index in the following days. The capability of a part of the synchronous population cells to preserve high proliferation rate during several days may be accounted for by the fact that the duration of the mitotic cycle of these cells is comparable with the duration of the rhythm period. The contribution of the asynchronous population into the formation of the peak rhythms in the mitotic activity is insignificant. However, this population proliferates actively enough during the periods of the decreased mitotic index.

[Effect of a single dose of hydroxyurea on cell division in the esophageal and lingual epithelium of mice]. / Vliianie odnokratnogo vvedeniia oksimocheviny na kletochnoe delenie v épitelii pishchevoda i iazyka myshei.

The mitotic index (MI), labeling index (LI) and the rate of 3H-thymidine nuclear incorporation (TNI) were revealed to decrease within the first hours after a single injection of hydroxyurea (HU) in doses of 100, 250 or 500 Mg/kg bw. After 9-12 hours the LI and MI exceeded the control level, while the TNI returned to normal. The degree of changes in the cell kinetics was found to depend on the dose of HU. The effect of HU on the proliferating cells proves, as a rule, to be temporary and reversible.

[Cell population kinetics and the cell population mechanism of circadian rhythm in the proliferative activity in the esophageal epithelium of mice maintained under constant illumination]. / Kinetika kletochynkh populaitsii i kletochno-populiatsonnye mekhanizmy sutochnogo ritma proliferativnoi aktivnosti v épitelii pishchevoda myshei, soderzhavshikhsia pri postoiannom osveshchenii.

3H-thymidine was injected to male mice maintained either on a 12 hour light-dark cycle or on a prolonged continuous light (LL-group) at the peak of DNA synthetic activity of the esophagus epithelium (1a. m). The parameters of the diurnal rhythm of cell division and mitotic cycle of the basal layer were studied. In the LL-group of animals, an expressive asynchronization of diurnal rhythm of mitotic index was found. At the same time the labelled cell population revealed a slight degree of asynchronization. The data suggest that the process of asynchronization of the overall kinetics in the tissue throughout the whole day is associated with differences in the state of separate cell populations entering mitotic cycle at the various time of the day. The mitotic cycle duration in both groups of animals is almost alike and equal to 24-27 hours, i. e. is close to that of the diurnal rhythm.

[Cell population kinetics and the cell population mechanisms of the circadian rhythm of proliferative activity in mouse esophageal epithelium]. / Kinetika kletochnykh populiatsii i kletochno-populiatsionnye mekhanizmy sutochnogo ritma proliferativnoi aktivnosti v épitelii pishchevoda myshei.

The dynamics of 3H-thymidine labeled mitosis and diurnal rhythm of proliferative activity was studied. The isotope was injected to BALB/C mice at the peak of diurnal rhythm of DNA synthesis activity of basal layer cells of oesophageus epithelium. It has been established that the increase in the mitotic index during 24 hours depends on the increase in number of cells being in S-period. The data show that the increase of mitotic index at diurnal rhythm occurs at the expense of 75% of new G0-cells which entered into the mitotic cycle, and of 25% of re-entering cells that had divided during the maximal mitotic activity a day before. It is found that the duration of mitotic cycle of cell population which entered into the mitotic cycle synchronously is almost equal to the period of diurnal rhythm of mitotic activity, i.e. 24 hours.

[Effect of an extract of mouse Ehrlich ascitic tumor cells on mitotic activity and DNA synthesis in that tumor]. / Deistvie ékstrakta kletok astsitnoi opukholi Erlikha myshei na mitoticheskuiu aktivnost' i sintez DNK v étoi opukholi.

The extract of Ehrlich's ascitis tumour cells depressed specifically the proliferative activity of this tumour cells. This was expressed in a marked reduction in the number of dividing and DNA-synthesizing cells after the extract injection. The mitotic index fell considerably as soon as 2 hours after the injection, reached the minimum in 4 to 5 hours and was restored to the control level in 9 to 12 hours. The radioactive index appeared to be evenly decreased in the course of 18 hours of the experiment.

[Cell population mechanisms of the diurnal rhythm of mouse hepatocyte mitotic activity]. / K voprosu o kletochno-populiatsionnykh mekhanizmakh sutochnogo ritma mitoticheskoi aktivnosti gepatotsitov myshi.

The dynamics of 3H-thymidine labeled mitosis and diurnal rhythm of mitotic activity was studied. The isotope was injected to BALB/c male mice at the peak of diurnal rhythm of DNA synthetic activity of hepatocytes. It has been established that the increase in the mitotic index during 24 hours depends on the increase in number of cells being in S-period. On the 2nd and 3rd days of investigation no labeled dividing hepatocytes were observed at the phases of increased mitotic index. The data allow to conclude that the increase of mitotic index at diurnal rhythm is at the expense of new GO-cells which entered the mitotic cycle, rather than due to the re-entering of cells that had divided during the maximal mitotic activity the day before.

[Tissue-specific inhibition of cellular proliferation in Ehrlich ascites tumor]. / Tkanevospetsificheskaia ingibitsiia kletochnoi proliferatsii v astsitnoi opukholi Erlikha

The extract of cells of ascitic Ehrlich's tumour (chaloun) and its cell-free fluid produced a marked inhibitory action on the cell proliferation of this tumour four hours after the administration. The effect is tissue-specific, more pronounced in the extract and depends on the dose of the antigen. Eight hours after the extract or the cell-free fluid administration the mitotic activity in the tumour proved to increase in comparison with control; this indicated the presence of a short-lived chaloun action on the G2-phase of the mitotic cycle and synchronization of cell division.

[Effect of thyroxine on the diurnal rhythm of the mitotic activity and parameters of the life cycle of cells of the liver and esophagus]. / Vliianie tiroksina na sutochnyi ritm mitoticheskoi aktivnosti i parametry zhiznennogo tsikla kletok pecheni i pishchevoda

The duration of the cellular cycle and the diurnal rhythm of the amount of mitosis were studied in young rats in normality and under the influence of thyroxin. The parenchymal and connective-tissue cells of the liver and cells of the liver and the cells of the oesophagus epithelium basal layer were studied. It was found that under the influence of thyroxin there occured a shortening of the periods of the cellular cycle and a 3--6 h shift to the left of the diurnal rhythm curve of the amount of mitoses. In thyroxinized animals the 21--95% increase of the amount of mitoses in the period of maximum values of the mitotic index during a day was observed as compared with control animals. A conclusion is made about the diurnal rhythm of sensitivity of G0-phase cells to the synchronizing factor, suggesting the decisive significance of the state of the cell population in the interaction of the tissue and hormone cells. The data obatained in the work show that the thyroid hormones regulate the cellular reproduction in the organism by stimulating the cells in the division cycle, synchronization of greater amount of cells by the moment of beginning of the mitotic cycle at a definite time of day and by shortening the period of the cell mitotic cycle.