Effect of melatonin on mitotic division of Gel'shtein 22A ascites hepatoma cells

The action of melatonin on mitosis of cells of the ascites form of Gel'shtein 22A mouse hepatoma was studied. Male C3HA mice with ascites for 7 days were used. A stathmokinetic reaction of the ascites hepatoma cells were found after intraperitoneal injection of melatonin. In concentrations of 200 and 100 g/g body weight, melatonin was shown to cause an increase in the mitotic index and accumulation of mitoses at the metaphase stage 3 h after injection.Laboratory of Chemical Factors of Regulation of Cell Growth and Division, Institute of Biological and Medical Chemistry, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. N. Orekhovich.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 11, pp. 595–596, November, 1979.     

Effect of nociceptive stimulation on mitotic activity of epithelial cells in skin surrounding a wound at different age periods

Wounds 1 cm long, down to the cutaneous muscle, were inflicted on rats aged 11 days, 2 months, and 2.5 months in the subscapular region. Nociceptive stimulation was applied to the animals by means of an electric current 48 h after the operation. Mitotic activity was determined in cells of the stratum basale of the skin epithelium adjacent to the wound. Nociceptive stimulation was found to reduce the mitotic index of the cutaneous epithelial cells of the animals of all age groups studied by a considerable degree (by several times). An increase in the mitotic index was observed from the early to the later stages of postnatal ontogeny.Laboratory of Age and Evolutionary Physiology, Voroshilovgrad Pedagogic Institute. Laboratory of Growth and Development, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 11, pp. 605–606, November, 1977.     

Regeneration and growth of the liver in 3-week-old mice of different strains

At the age of 3 weeks, C57BL mice have comparatively low proliferative activity of their hepatocytes when the liver grows normally, but also during regeneration of the liver 44 h after its extensive resection (mitotic index 16%). Animals of the same age but of other strains (noninbred, CBA, and CC57BR), however, in most cases have a higher mitotic index of their hepatocytes both under normal conditions and during regeneration of the liver (42, 70, and 60%). This pattern of interlinear differences in mitotic activity of the hepatocytes during growth and regeneration of the liver was still found 7 days after the beginning of the experiment. The results indicate genetic determination of the level of proliferative activity of cells.Laboratory of Growth and Development, Institute of Human Morphology, Academy of Medical Sciences of the USSR. (Presented by Academician of the Academy of Medical Sciences of the USSR, A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 4, pp. 475–477, April, 1976.     

Shortening of the prereplicative period of the mitotic cycle of hepatocytes during repeated stimulation of division

Repeated stimulation of division at a short interval (2–3 days) after the first division causes shortening of the prereplicative period of the mitotic cycle of hepatocytes in the regenerating rat liver to 9–10 h. Cells dividing a second time after one stimulation passed through the G₁ period of the second mitotic cycle in the same length of time. It is suggested that cells with the minimal duration of the prereplicative period do not pass through a period of transformation. With an increase in the time between successive stimulations of division (to 4–5 days) the duration of stay in a resting state was increased for most hepatocytes and they lost their ability to maintain a shortened prereplicative period.Laboratory of Chemical Factors of Regulation of Growth and Cell Division, Institute of Biological and Medical Chemistry, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. N. Orekhovich.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 1, pp 64–67, January, 1978.     

Effect of prolonged administration of nitrazepam on sleep cycles in rats

The effect of nitrazepam given as a single dose or by prolonged intraperitoneal injection, on sleep cycles in male Wistar rats was studied. In a dose of 1 mg/kg nitrazepam had no significant effect on sleep cycles whether given as a single or by prolonged injection. In a dose of 10 mg/kg a single injection of nitrazepam reduced the duration of paradoxical sleep and the number of sleep cycles during 5 h of recording, whereas prolonged (7–14 days) administration of the drug led to an increase in these indices. Withholding the drug after its prolonged administration was followed by a further increase in the number of sleep cycles and the duration of paradoxical sleep. No correlation was found between the hypnotic and muscle-relaxing action of nitrazepam during its prolonged administration.Institute of Pharmacology, Academy of Medical Sciences of the USSR, Moscow. Institute of Pharmacology, Czechoslovak Academy of Sciences, Prague. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 2, pp. 188–190, February, 1976.     

Correlation between doubling time of volume of human lung tumors and labeling index

The labeling index (incubation with thymidine-H³) and the volume doubling time (repeated roentgenography) were compared for three human lung tumors: two squamous-cell carcinomas with different levels of differentiation, and one hamartoma. The minimal doubling time (178 days) was found for the squamous-cell carcinoma with a lower level of differentiation and with the highest labeling index (19.0%). The hamartoma (a benign lung tumor) had the longest doubling time (1250 days) and the smallest labeling index (3.8%).Sector of Kinetics of Chemical and Biological Processes, Institute of Chemical Physics, Academy of Sciences of the USSR. Thoracic Department, Institute of Experimental and Clinical Oncology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 1, pp. 59–61, January, 1976.     

Electron-microscopic study of the mouse myocardium in experimental Coxsackie A13 virus infection

Diffuse degenerative-proliferative myocarditis is described in adult BALB/c mice infected with Coxsackie A13 virus. A marked tendency was observed for sclerotic processes to develop 30–60 days after infection; this may lie at the basis of the reduced functional activity of the myocardium and may lead to the development of cardiomyopathy.Institute of Clinical and Experimental Medicine, Siberian Branch, Academy of Medical Sciences of the USSR. Novosibirsk Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. P. Kaznacheev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 4, pp. 489–491, April, 1977.     

A rapid method of inducing amyloidosis in mice

A new modification of the casein model of amyloidosis in mice is suggested, whereby the time for development of amyloidosis is reduced to 5–10 days.Laboratory of General Pathological Anatomy, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 5, pp. 634–635, May, 1978.     

Changes in mitotic activity of the corneal epithelium of albino rats cooled at different times of day

The effect of moderate hypothermia on mitotic activity of the corneal epithelium of albino rats was studied. The animals were cooled to 28°C by a contact method for 1 h. Cooling was carried out in the early morning (6 a.m.), at noon, and in the evening (6 p.m.). The response of the epithelium to cooling was found to depend on the time of day. The most marked inhibition of mitotic activity (by 14 times) occurred in the afternoon, 3 h after cooling at noon. A tendency toward restoration of normal cell division was observed 6 and 12 h later. The number of mitoses was reduced 3 h after cooling in the evening, but no changes in mitotic activity were discovered 6 and 12 h later. No changes were found 3 and 6 h after cooling in the morning, but 12 h later cell division was inhibited.Central Scientific-Research Laboratory, Khabarovsk Medical Institute. Laboratory of Cytology, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 82, No. 11, pp. 1371–1373, November, 1976.     

Effect of chronic pyrogenal stress on the mitotic regime and number of DNA-synthesizing cells in the corneal and lingual epithelium of albino rats

The effect of prolonged stress on the mitotic regime and number of DNA-synthesizing cells in the corneal and lingual epithelium was studied in response to pyrogenal. Injection of pyrogenal for 5 days caused a decrease of 41% in the number of mitoses in the corneal and lingual epithelium. The decrease in the number of dividing cells did not correlate with changes in the rate of mitosis. The number of pathological mitoses in the corneal epithelium of intact rats remained unchanged during stress. The index of labeled nuclei in the corneal and lingual epithelium of the control rats was 12.6 and 10.8 respectively, which did not differ significantly from their values in the experimental animals (12.2 and 12.2).Central Research Laboratory, Khabarovsk Medical Institute. Laboratory of Cytology, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 8, pp. 248–250, August, 1978.     

Effect of injury to the maternal liver on reactive changes in the liver of the young

The liver of young rats aged 30 days was studied spectrocytophotometrically (content of glycogen, amino acids, RNA, and DNA) and morphometrically (size of the nuclei and nucleoli, mitotic index) 48 h after intragastric administration of CCl₄. Toxic hepatitis had been produced in the mothers of these rats before pregnancy. The results indicate that previous hepatitis in the mother not only affected the morphological nature and histochemical properities of the liver of the progeny, but also led to considerable changes in the response of the hepatocytes to administration of the poison, for the harmful effect of the hepatotoxin was increased.Group for Fetoplacental Pathology, Institute of Clinical and Experimental Medicine, Siberian Branch, Academy of Medical Sciences of the USSR. Central Research Laboratory, Novosibirsk Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. P. Kaznacheev.). Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 9, pp. 1114–1116, September, 1976.     

Extracellular pH, [K+], and synaptic transmission in the dorsal horn of the spinal cord of hypercapnic rats

P. K. Anokhin Research Institute of Normal Physiology, Academy of Medical Sciences of the USSR, Moscow. Research Institute of General Pathology and Pathological Physiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR K. V. Sudakov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 113, No. 1, pp. 8–10, January, 1992.     

Changes in resistance of partially hepatectomized mice to transplantable tumors in the final stage of regeneration of the liver

When an ascites form of hepatoma 22a was transplanted intraperitoneally into A/he mice 1–12 days after partial hepatectomy two periods of inhibition of its growth were observed. The first 24 h after the operation and the second 3–10 days later. Animals most resistant to transplantation of this particular tumor (5–8 days after transplantation of sarcoma 37 and Ehrlich's adenocarcinoma.Laboratory of Growth and Development, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 326–328, March, 1977.     

Parental resistance of irradiated mice to (CBA×M523) F1 lymphocytes. fate of transplanted cells,duration of resistance,and its specificity

The immunologic resistance of (CBA x M523)F₁ mouse lymphocytes to a foreign antigen (sheep's red blood cells) in lethally irradiated CBA mice was investigated. If irradiation, transplantation of the cells, and the test injection of antigen were carried out on the same day, the activity of the graft was inhibited (compared with a syngeneic system); if the interval between these operations was increased to 3 days the activity of the donor's cells was restored. Retransplantation of recipients' spleen cells into irradiated CBA and F₁ mice showed the viability of the transplanted cells and absence of their readaptation to the nonsyngeneic microenvironment. The resistance of the recipients could be specifically overcome by previous injection of cells from F₁ mice in combination with or without cyclophosphamide. It can be concluded from the results that genetic parental resistance of CBA mice to cells of F₁ mice is due to the recipient's immunologically competent cells, which are inactivated 3 days after irradiation. They have no cytotoxic action on the donor's cells but temporarily restrict their activity.N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR. Research Laboratory of Experimental Biological Models, Academy of Medical Sciences of the uSSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR O. V. Baroyan.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 87, No. 5, pp. 441–444, May, 1979.     

Effect of repeated cooling on the state of the adrenals and proliferation of the corneal epithelium in albino rats

The effect of repeated cooling on the state of the adrenals and on the mitotic cycle and number of DNA-synthesizing nuclei in the corneal epithelium was studied in albino rats. The animals were cooled by a contact method to a body temperature of 28°C and exposed at that temperature 1 h daily for 5 days. Marked activation of the adrenals was observed: The weight of the glands was doubled, their cholesterol concentration reduced by two-thirds, their blood 11-hydroxycorticosteroid level increased fourfold, and their adrenalin excretion stimulated. The mean number of mitoses in the cornea was reduced by half. The depression was not connected with any change in the rate of mitosis but was due to delay in interphases. There was no change in the level of pathological mitoses. Chronic exposure to stress was not accompanied by any change in the number of DNA-synthesizing nuclei or the intensity of DNA synthesis.Central Research Laboratory, Khabarovsk Medical Institute. Laboratory of Cytology, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 7, pp. 87–89, July, 1979.     

Mitotic cycles of hepatoma 22A cells

The duration of the mitotic cycle on the 2nd, 5th, 8th, and 11th–12th day of development of the ascites variant and on the 10th and 15th days of development of the solid variant of hepatoma 22A was determined by an autoradiographic method in the cells of this tumor. The duration of the mitotic cycle of the cells of the ascites variant was found to increase considerably during the life of this strain (the duration of the S-period increased from 14 to 26–27 h and of the G₂-period from 2.2 to 13 h). The duration of the mitotic cycle in cells of the solid variant of hepatoma 22A was the same at both times of development of this tumor. Correlation was found between changes in the duration of the mitotic cycle during the life of the strain of tumor cells and its changes with an increase in the period after the first passage of that strain.Laboratory of Chemical Factors for the Regulation of Cell Growth and Division, Institute of Biological and Medical Chemistry, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. N. Orekhovich.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 78, No. 8, pp. 97–99, August, 1974.     

Antibody-forming capacity of mouse spleen cells after hypoxic hypoxia and injection of erythropoietin

The absolute and relative (per 10⁶ spleen cells) number of antibody-forming cells (AFC) in the spleen of CBA mice was found to be reduced by half of the 1st, 4th, and 7th days after acute hypoxia (12 h, 6700 m) and on the 1st and 4th days after the end of exposure to chronic hypoxia (16 h daily for 16 days, 6700 m). By the 7th day after the end of exposure to chronic hypoxia the number of AFC in the spleen of the mice was back to normal. One of two injections of erythropoietin reduced the absolute and relative number of AFC in the spleen of the posthypoxic mice by 33–50% compared with control animals.Laboratory of Regulation of Immunopoiesis, Institute of Clinical and Experimental Medicine, Siberian Branch, Academy of Medical Sciences of the USSR, Novosibirsk. (Presented by Academician of the Academy of Medical Sciences of the USSR V. P. Kaznacheev.) Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 85, No. 5, pp. 565–567, May, 1978.     

Antiepileptic effects of IOS-1.1212, a new calcium channel blocker

Research Institute of General Pathology and Pathological Physiology, Academy of Medical Sciences of the USSR, Moscow. Institute of Organic Synthesis, Latvian Academy of Sciences, Riga. (Presented by Academician of the Academy of Medical Sciences of the USSR A. D. Ado.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 112, No. 10, pp. 362–365, October, 1991.     

Changes in mitotic activity in the corneal epithelium of rats of different ages after nociceptive stimulation

The effect of nociceptive stimulation on mitotic activity in the corneal epithelium was investigated in 21-day-old rat fetuses and in rats aged 3, 4, 5, 7, 10, 15, 20, and 25 days. Mitotic activity was not significantly changed 45 min after nociceptive stimulation of the animals (amputation of one-third of the tail) in the corneal of the fetuses and day-old rats. Between the 3rd and 10th days of postnatal development reactive inhibition of mitosis in response to nociceptive stimulation was gradually formed. After 10 days this response was intensified and reached a maximum by the 25th day. Reactive inhibition of mitotic activity is connected with delayed entry of the cells into mitosis.Department of General Biology, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Kupriyanov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol 82, No. 11, pp. 1367–1369, November, 1976.     

Dynamics of transcription activity of cerebellar Purkinje cell chromatin after systemic circulatory arrest

Institute of General Resuscitation, Academy of Medical Sciences of the USSR. N. I. Pirogov Second Moscow Medical Institute N. K. Kol'tsov Institute of Developmental Biology, Academy of Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR. V. A. Negovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 111, No. 3, pp. 232–235, March, 1991.