Quantitative determination of epidermal G2-chalone-like factor by radial immunodiffusion

A homogeneous high-molecular-weight glycoprotein possessing tissue-specific, but not species-specific antimitotic activity relative to epithelium of dermal type (epidermal G₂-chalone) was isolated electrophoretically and immunochemically from rat skin. A method of quantitative immunodiffusion determination of this substance by means of monospecific antiserum in certain tissues is described. Clear correlation between the mitotic index and concentration of G₂-chalone in the mucous membrane at various stages of the estrous cycle was demonstrated in the vaginal epithelium.Laboratory of Experimental Tumors, Professor N. N. Petrov Research Institute of Oncology, Ministry of Health of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. I. Ioffe.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 7, pp. 114–116, July, 1979.     

Action of thyroxine on mitotic cycle of cell cultures

Thyroxine, in a dose of 10 g/ml, differed in its effect on the various periods of the mitotic cycle of HeLa cell cultures in the logarithmic and stationary phases of growth. In the logarithmic phase thyroxine shortened only the G_2min-period (by 2 h) and had no effect on the duration of the other phases of the mitotic cycle. In a stationary culture thyroxine shortened the total duration of the mitotic cycle by 3–7 h, mainly on account of a decrease in the time spent in the G₁+1/2M periods (by 4–8 h) and, to some extent, the G_2min-period (by 1 h). It is concluded that the hormone stimulates the entry of the cells into the mitotic cycle from the G₀-period in the stationary culture.Department of Biology and Genetics, Medico-Biological Faculty, 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. 9, pp. 1121–1123, September, 1976.     

Rate of passage through the first mitotic cycle by ascites hepatoma 22A cells of different ages after stimulation of division

The rate of passage through the first mitotic cycle by ascites hepatoma 22A cells of different ages after the stimulation of division was studied. Aging (11 days old), terminal (14 days), and delayed (4 days older than terminal) ascites fluid was used. The highest values of the index of labeled nuclei (due mainly to the transition from the resting state of the cells into the S period) were found to occur toward 9–12 h, and of the mitotic index toward 18–21 h after transplantation regardless of the age of the tumor. It follows from these results that the duration both of the prereplicative (G₁) period and of the whole of the first mitotic cycle after stimulation of division is independent of the duration of stay of the ascites hepatoma 22A cells in the resting state (or the very protracted G₁ 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. I. Orekhovich.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 2, pp. 218–220, February, 1977.     

Effect of one and two injections of chalone isolated from mouse Ehrlich's ascites tumor on its mitotic activity

Chalone from Ehrlich's ascites tumor has a short and reversible inhibitory action on proliferation of cells of this tumor when administered as both one and two injections. A considerable increase in mitotic activity in the tumor cells compared with the control is observed 10 h after one or two injections (the second injection being given at 6 p.m.) of the chalone, indicating that it acts on the G₂-cell population in the mitotic cycle and that it synchronizes cell division. If the second of two injections of chalone is given at 9 p.m. it leads to more prolonged inhibition of the cells and to a more marked synchronization wave of the G₂-cell population. The duration of inhibition of cells in the G₂-phase of the mitotic cycle after two injections of the chalone thus depends on the state of the cell population on which the chalone acts.Department of Biology and Genetics, Medico-Biological Faculty, 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. 89, No. 2, pp. 189–191, February, 1980.     

Response of cardiomyocytes of the right heart to trauma of the left

A myocardial infarct in the left ventricle was produced in adult rats weighing 120–160 g by ligation of the left coronary artery; the left atrium was injured; or a mock operation was performed and the pericardium was removed. On the fifth day after the operation dividing myocytes were found in the right atrium (mitotic index 0.7–8.8) and in the subepicardial zone of the right ventricle (mitotic index 0.8–2.9). In old rats weighing 300–430 g, on the third day after the various types of injury to the myocardium, mitotic activity was found in the myocytes of the left auricle (1–5.1), and in one of eight cases in the right auricle (4.2); single mitoses also were found in the subepicardial zone of the left ventricle.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. 5, pp. 610–612, May, 1977.     

α-Fetoprotein production in regenerating mouse liver synchronizedin vivo

Liver cells regenerating after CCl₄ poisoning were synchronizedin vivo by continuous administration of hydroxyurea. Accumulation of hepatocytes at the G₁-S phase boundary or in the S-phase did not affect the course of changes in the blood -fetoprotein (-FP) levels or the characteristic location of -FP for regenerating liver for 2 or 3 days after poisoning. -FP production began in the hepatocytes before their entry into the S-phase, and -FP was found in the cells also at different times after they had ended their mitotic cycle. No dependence of -FP synthesis on any particular phase of the mitotic cycle could be observed.Laboratory of Immunochemistry and Diagnosis of Tumors, Oncologic Scientific Center, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR L. M. Shabad.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 3, pp. 346–349, March, 1980.     

Action of hemolysate of polycythemic animals on proliferations of bonne marrow cells

Erythrocytic inhibitor from polycythemic rats depressed mitotic activity of cells of of the erythroid series in mice by 40%. The inhibitory effect lasted about 12 h. The inhibitor acted on the G₂ period. The points of application of the inhibitor were not only blast forms of the erythron but also hematopoietic stem cells.Department of Pathological Physiology, Moscow Medical Stomatological Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Fedorov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 337–339, March, 1977.     

Immunoautoradiographic determination of β1−G-globulin in the blood serum of patients with trophoblastic tumors

The results of determination of _1–G-globulin by immunoautoradiographic (IAR) and immunodiffusion (ID) methods in the blood serum of patients with trophoblastic tumors are compared. When negative results were obtained by the ID method, _1–G-globulin was found by means of the IAR method in seven of eight tests in chorionepithelioma of the uterus before treatment and in seven of 21 tests of the blood serum from patients of the same group after treatment. In the early stages of development of chorionepithelioma of the uterus (the state after hydatidiform mole, malignant hydatidiform mole) _1–G-globulin was found by the IAR method 4.5 times more frequently than by the ID method. This globulin was also found by the IAR method in testicular teratoblastoma with elements of chorionepithelioma. No -globulin could be found by the IAR method in the blood serum of other oncologic patients or donors.Department of Biochemistry, Problem Laboratory for Immunochemistry of Malignant and Embryonic Tissues, N. I. Pirogov Second Moscow Medical Institute. Laboratory of Immunochemistry of Tumors, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR. 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 N. A. Kraevskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 80, No. 9, pp. 86–89, September, 1975.     

Effect of the normal microflora and age and sex of rats on the serum IgG2 level

Germfree and ordinary rats, bred in the laboratory, and rats obtained from nurseries were used. IgG₂ was isolated from the serum of noninbred rats and a rabbit antiserum against it obtained. By radial immunodiffusion the quantity of this immunoglobulin was determined in the blood serum of different groups of animals. The IgG₂ content in germfree rats of the Fisher strain was only 19% of that in animals of this strain obtained from the nursery, and in females it was 10–15% higher than in males. The IgG₂ level in newborn rats within a few hours after birth was identical regardless of its concentration in the maternal blood serum. The results may be used as standards for various immunological experiments on rats.Laboratory of Gnotobiology, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR P. A. Vershilova.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 9, pp. 335–337, September, 1978.     

Effect of repeated partial hepatectomy on cell division in the regenerating rat liver

Repeated partial hepatectomy (PH), performed 24 h after a 70% PH, had the following effect on the mitotic cell cycle in the regenerating rat liver: it delayed (by about 2 h) the cells in the G₂ period, left the S period almost unchanged, and delayed the cells for 6–8 h in the G₁ period. A mock repeated operation had a similar effect. This indicates that the influence of the repeated PH on the mitotic cell cycle in the regenerating liver is due to operation stress. Additional stimulation of division by repeated PH affects the character of the regeneration process as a whole.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. 84, No. 10, pp. 488–491, October, 1977.     

Characteristics of the mitotic cycle of ascites hepatoma 22A cells in the terminal stage of development

The characteristics of growth of ascites heptoma 22A in the terminal stage of development were studied. It was shown by an autoradiographic method that some cells may be in the G₁-or R₁-period for 2 or even 4 days. The mean duration of the G₂-period was 16 h. Of the total number of cells 55–60% were in the greatly lengthened G₁- and R₁-period, 7% in the S-period, and 9% in the G₂-period. The remaining 25–30% of cells evidently had irreversibly left the mitotic cycle, for they did not participate in proliferation in response to stimulation of cell division.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. 86, No. 10, pp. 479–482, October, 1978.     

Tissue-specific inhibition of cell proliferation in Ehrlich's ascites tumor

Extract of Ehrlich's ascites tumor cells (chalone) and its cell-free fluid have a marked inhibitory action on proliferation of these tumor cells 4 h after injection. The effect is tissue specific, it is more marked in the extract, and it depends on the dose of the agent. Mitotic activity in the tumor 8 h after injection of the extract or cell-free fluid is higher than in the control, evidence of a short-term effect of the chalone on the G₂ phase of the mitotic cycle and on synchronization of cell division.Department of General Biology and Genetics, Medico-Biological Faculty, 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. 12, pp. 1477–1479, December, 1976.     

Duration of the mitotic cycle of chinese hamster cells cultured at 30–39°C

The duration of the mitotic cycle (T) and of its stages at temperatures of 30, 33, 36, and 39°C was studied by an autoradiographic method in Chinese hamster cells of subline 237. The duration of the mitotic cycle was shortest at 39°C and increased as the cultivation temperature fell. Within the temperature range 33–39°C the increase in duration of the mitotic cycle and its stages was proportional to the temperature studied. The slope of the curve of duration of the mitotic cycle as a function of temperature increased sharply as the temperature changed from 33 to 30°C. The G₁ period was most sensitive and the G₂ period least to a change in the cultivation temperature.Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 11, pp. 1365–1367, November, 1976.     

Combinatorial relations in the EEG spectrum

The mean geometric frequency f₁ of each EEG wave divides its frequency band B=f₂–f₁ into subbands b and s. For the wave the values of s, b, and B are elements of a geometric progression with denominator equal to the invariant F of the golden section. It is postulated that all EEG waves are characterized by an S_G system of recurrent equations, obtained by combinatorial generalization of a Fibonacci generating function. Theoretical invariants of the S_G system coincide with experimental b/s ratios with a standard error of 1%. The S_G system predicts the existence of and EEG waves (55–118 and 118–225 Hz), which have not yet been found experimentally.Interdepartmental Teaching Laboratory, Moscow Energetics Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Fedorov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 80, No. 7, pp. 11–14, July, 1975.     

Effect of sex and the phase of the estrous cycle on intensity of injury and repair processes in the liver of rats with acute carbon tetrachloride poisoning

The pattern of injury and repair in the liver of Wistar rats depending on sex, the phase of the estrous cycle, and also under the conditions of deficiency of female sex hormones and after injection of -estradiol into ovariectomized rats was studied by morphometric, histo chemical, and electron-microscopic methods. Structural disturbances caused by CCl₄ were found to be increased and reparative reactions inhibited in the liver of females both during the period of a natural increase in the blood estrogen concentration and under the influence of exogenous estradiol, and ovariectomy also had a protective effect. In males, structural changes in the liver were more marked than in females with a low blood estrogen level and differend only a little from those in females during the period of increased secretion of sex steroids.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. 85, No. 4, pp. 460–464, April, 1978.     

Investigation of the cytostatic action of cyclophosphamide on esophageal tumors and epithelium in mice

The cytostatic action of cyclophosphamide on sarcoma 37 and the esophageal epithelium was investigated in albino mice by determination of the diurnal rhythms of mitotic activity and the number of labeled nuclei. Tumor cells were shown to be most sensitive to the inhibitory action of the compound evidently in the G₁ phase at the beginning of the S phase. As the period of DNA synthesis came to an end, the resistance of the cells to the cytostatic increased. Cells in the G₁ phase of the mitotic cycle in the esophageal epithelium are sensitive to the inhibitory action of cyclophosphamide.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. 593–595, November, 1977.     

Dynamics of reactivity of mesenteric microvessels in rats with experimental renal and hormonal hypertension

Reactivity of mesenteric arterioles 10–30 in diameter to application of histamine (100–500 g) adrenalin, and noradrenalin (1–10 g) was studied in rats with experimental renal and hormonal hypertension. The sensitivity of the microvessels to the vasoactive substances was shown to vary with the stage of development of experimental hypertension.Laboratory of General Pathophysiology and Experimental Therapy, 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 A. M. Chernukh.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 2, pp. 150–152, February, 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.     

Kinetics of cell proliferation in the regenerating rat liver after subtotal resection

Between 78 and 82% of the weight of the liver was resected in noninbred male rats. Maximal mitotic activity of the hepatocytes was observed 38–48 h after the operation. Pulse labeling with [³H]-thymidine showed that the G₂ period is 6 h and the minimal duration of the S period is also 6 h. During regeneration of the liver after subtotal resection asynchronization of the entry of the hepatocytes into the S period and mitosis and delay of the cells in the G₁ and G₂ periods were observed. The above-mentioned changes in proliferation of the hepatocytes are the result of a disturbance of intracellular metabolism in response to an extremal functional demand.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. 86, No. 12, pp. 723–726, December, 1978.     

Biosynthesis of renal prostaglandins in spontaneously hypertensive rats

The biosynthesis of prostaglandins (PG) E₂ and F₂ from [¹⁴C]arachidonic acid by renal medullary tissue of rats with spontaneous hypertension and of normotensive Wistar rats was investigated at different ages (1.5 and 3.5 months). In animals with spontaneous hypertension the synthesis of PG E₂ from arachidonic acid was at a much lower level than in Wistar rats. The biosynthesis of PG F₂ in these animals was virtually indistinguishable from normal. No age differences were found in PG formation by the kidneys of rats with spontaneous hypertension, whereas in Wistar rats PG E₂ biosynthesis was depressed at the age of 3.5 months.Laboratory of Pathophysiology, Institute of Pediatrics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of medical Sciences of the USSR A. M. Chernukh.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 6, pp. 659–661, June, 1977