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Biomedical subjects

T P Riabykh

Publications and source records attributed to T P Riabykh.

At least 19 recordsLinked to original sources
PubMed2000

[Effects of biorhythm regulator melatonin on DNA synthesis in short-term cultures of human malignant tumors].

The cytotoxic action of melatonin on DNA synthesis was studied in short-term human tumor tissue cultures. Twenty tumors (ovarian, renal, colorectal, gastric, skin, testicular, thyroid, adrenal gland, endometrial, cervical uterus ones, and melanoma) were isolated from patients at surgery. The effect of melatonin (concentrations of 5 x 10(-5) M to 5 x 10(-13) M on the level of 3H-thymidine incorporation into tumor tissue DNA (4-hour exposure) was evaluated. After exposure, 3H-thymidine was added to the medium for an hour. The quantity of DNA was determined in the hydrolysate by spectrometry; the level of 3H-thymidine incorporation into DNA was radiometrically evaluated by a scintillation counter. The quantity corresponding to 3H-thymidine incorporation per unit of DNA was determined. The control group and the melatonin-treated groups were compared by ANOVA. Melatonin inhibited DNA synthesis in 11 (55%) of the 20 tumors and was ineffective in 9 (45%) of the 20 ones. Melatonin-sensitive tumors were as follows: endometrial CA (33% vs 75% inhibition, p < 0.01), gastric CA (71% inhibition, p < 0.05), adrenal gland CA (38% inhibition, p < 0.01). Ovarian, cervical, skin CA and melanoma were unresponsive to melatonin. Renal cell CA, colonic and rectal CA were sensitive in some cases. In sensitive tumors, melatonin was effective even at concentrations of 5 x 10(-13) M to 5 x 10(-7) M. Thus, melatonin has an oncostatic effect on some human tumors in vitro occasionally at physiological concentrations.

Adult↗
PubMed1996

[Correlation of MMTV antibody expression and risk factors of human breast cancer].

Incidence of sera with antibodies to MMTV-related proteins has been studied in a cohort at high risk for breast cancer including healthy females and those with benign breast disease. The results were evaluated versus certain risk factors of breast cancer. No significant difference in the incidence was established between cases of diffuse fibrocystic mastopathy and healthy subjects. Nor was there any relationship between positive serum incidence and age, number of abortions, age at first childbirth or postmenopause. However, this parameter appeared to be in direct correlation with the number of childbirths (beginning from 3). This index was significantly higher in women (aged 40 and more) with early menarche than in those with medium and late menarche (8 and 0%, respectively).

Adult↗
PubMed1992

[A correlation between the cellular composition of the spleen and the change in splenocyte chemiluminescence after laser irradiation].

Chemiluminescence (CL) of splenocytes of A/Sn mice (1.5-9-month old) was recorded after irradiation of the cells with lambda semiconductor laser at 820 nm (dose 1.1 x 10(3) J/m2, pulse repetition rate 292 Hz). Laser radiation was found to stimulate or suppress the spontaneous CL (SCL) of splenocytes, the amplitude and its sign depending on cellular composition of the spleen. Direct correlations between effect of laser radiation (per cent in changes in SCL) and per cent of plasmatic cells (r = 0.743, p < 0.001), neutrophils (r = 0.650, p < 0.001) and myelocytes and metamyelocytes (r = 0.507, p << 0.01) were established. The correlation with per cent of lymphocytes (r = -0.590, p < 0.001) was found to be a reverse one.

Aging↗
PubMed1988

[Specificity of antibodies against structural proteins of the mouse mammary cancer virus in healthy women and in mastopathy].

The immunoenzyme technique was used to identify sera reacting with mouse mammary tumor virus (MMTV) proteins in patients with mastopathy and healthy subjects. Their specificity to certain viral proteins was established by immunoblotting. Serum samples obtained from 14 subjects reacted mainly with p27 MMTV, while those taken from another two subjects--mainly with gp52 virus. Humoral antibodies against p27 MMTV were found in 3.3% of the entire study group whereas anti-gp52 antibodies--in 0.5%.

Antibodies, Viral↗
PubMed1987

[Antibodies interacting with the proteins of the mammary cancer virus (MMTV) in the sera of healthy women].

Using enzyme-linked immunoassay (ELISA), sera of 405 women without breast cancer were screened for the presence of antibodies to mouse mammary tumour virus proteins. 16 donors with positive sera were identified (3.96 +/- 0.97%). An attempt was made to establish the correlation between the age, ovarian Activity, benign breast disease and other factors and the appearance of antibodies to mouse mammary tumour virus. No statistically significant differences have been revealed among women aged 20-29 (3.92%), 30-39 (4.69%), 40-49 (4.08%) and 50-59 (2.38%), as well as in premenopausal (4.31%) and postmenopausal (4.5%) women and women with simple fibromatous disease (4.76%) and without any mammary gland pathology.

Aging↗
PubMed1987

[Ultradian fluctuations in the natural antitumor resistance of mice undergoing transplantation and chemical carcinogenesis].

A study was made of the mouse life span in relation to the time of tumor cell injection on an hourly basis, while the carcinogenic effect was studied in relation to the time of urethan injection. Changes in both the values were shown to vary with ultradian rhythms. It was found that natural killer cell activity against tumor cells, migration index of normal spleen cells in the presence of tumor cells and the activity of carcinogen-metabolising enzyme system of intact animals also exhibited ultradian oscillations. It is assumed that oscillations of natural resistance against transplantable or chemically-induced tumor may be due to the changes of these parameters.

Activity Cycles↗
PubMed1983

[Ultradian biorhythms in mouse bone marrow].

Ultradian oscillations in the number of karyocytes isolated from the femoral bone of intact ACR mice have been demonstrated. The periodicity of oscillations did not depend on the season or the site of mice breeding. The bone marrow also showed ultradian oscillations in relative and absolute amount of lymphoid, myeloid and mitotic cells. It is postulated that differentiation and migration of bone marrow cells might have ultradian biorhythms.

Animals↗
PubMed1981

[lymphoid organ pulsation].

Intact mice showed circadian rhythms of changes (pulsations) in the weight of the lymphoid organs, in the number of nuclear cells, as well as in the activity of serum factor(s) modifying lymphocyte migration in vitro. The pulsations were manifested by a short-term (over 1-4 h) twofold increase in the weight of the thymus, spleen and lymph nodes and in the number of cells contained by these organs. Sera from the animals with the enlarged organs inhibited the migration of thymocytes and spleen cells in vitro. The increased migration followed the maximal weight and the maximal number of cells of the lymphoid organs. It is suggested that pulsations seen in the lymphoid organs might reflect the mechanism of lymphocyte recirculation monitored by humoral mediators.

Animals↗
PubMed1977

[Phenols as toxic metabolites of benz(a)pyrene].

The effect of benzo(a)pyrene and two its phenolic metabolites 3-hydroxybenzo(a)-pyrene and 6-hydroxybenzo(a)pyrene--on the cultures of normal and transformed fibroblasts has been studied. In was shown that unlike the parent carcinogen its phenolic metabolites exerted only toxic (but not transforming) effect on cultured cells, and this effect has been developed at a faster rate than that produced by benzo(a)pyrene. 6-hydroxybenzo(a)pyrene was more toxic than 3-hydroxybenzo(a) pyrene. It was concluded that both metabolites produced their effects without preliminary activation by microsomal enzymes.

Animals↗
PubMed1977

[Respiration of the cells and isolated mitochondria of the rat liver in the early stages of hepatocarcinogenesis].

Under study was the respiration of mitochondria and cell aggregates (slices) of rat liver during the process of chemical carcinogenesis, induced by 3'-Me-DAB and AAP. The study of the hepatic mitochondria respiration indicated no impairment of the mitochondria functions investigated at early stages of carcinogenesis. The examination of hepatic slices respiration has demonstrated that during the process of chemical carcinogenesis the stimulation of endogenic respiration affected by DNP is decreased, whereas such effect is not observed while using succinate as a substrate. During the carcinogens metabolism compounds are assumed to be formed, those are able to affect oxidative phosphorylation without forming any stable link with the respiratory chain components. Which of the carcinogens metabolites may render similar effects is the question to be discussed.

2-Acetylaminofluorene↗
PubMed1976

[Effect of uncoupling agents and benz (a) pyrene metabolites on respiration in L cells and normal mouse embryonal fibroblasts].

A method is proposed for a polarografic study of the respiration of cell suspensions obtained from monolayer cultures of L-cells and from normal embryonic fibroblasts of mice (C3HA line). 6-hydroxybenzo(a)pyrene (6-OHBP). The metabolite of the carcinogenic hydrocarbon benzo(a)pyrene, was shown to be a strong uncoupler of of oxidation and phosphorylation of cell suspensions. Its effect was influenced by the presence of calf serum in the incubation media. Possible relationships between the toxic effect of 6-OHBP on monolayer cultures of normal and tumor cells, and its effect on cell energetics are discussed.

Animals↗
PubMedDate not supplied

[Correlation of the probability of occurrence of breast neoplasms with solar activity].

A contingent with high incidence of precancerous breast diseases (1080 persons) was studied to assess the relationship between solar activity and 1) alterations in the relationship between women with early menarche and women with middle and late menarche (high and low risk of breast cancer respectively) and 2) incidence of benign breast diseases. It was established that population content alterations were wave-like and had statistically significant periods 3,5; 7 and 12 years, and correlate with Wolf number changes. Incidence of benign breast diseases in the group aged 20-50 years also changed periodically (T = 11 years) depending on the birth-year and correlated conversely with Wolf numbers at the birth-years. Incidence of benign breast diseases changes periodically in the population of women with early menarche with the period of 3.6 years, and in those with middle and late menarche--with the periods of 10.5, 3.2 and 4 years. There is a statistically significant correlation between the incidence of benign breast diseases and Wolf numbers in population of women with middle and late menarche.

Breast Diseases↗
PubMedDate not supplied

[Connection between the sector structural of the interplanetary magnetic field and hematologic indicators in normal and neoplastic processes].

Interplanetary magnetic field (IMF) sector polarity was compared to hematologic indexes of normal mice and mice after single injection of carcinogen 1,2-Dimethylhydrazine. It has been established that the hemoglobin level and the number of leucocytes in the standard blood volume depend on IMF sector polarity: both indexes are higher at +IMF, than at -IMF. Mice injected with carcinogen have mainly higher hemoglobin level at +IMF and mainly lower one at -IMF than the control mice.

1,2-Dimethylhydrazine↗
PubMedDate not supplied

[Effect of He-Ne laser radiation on the chemiluminescence of mouse spleen cells].

A study was made of He-Ne laser radiation (lambda = 632.8 nm) on spontaneous chemiluminescence of mouse splenic cells and that stimulated by addition of Candida albicans. Irradiation with low-intensity red light was shown to stimulate cell chemiluminescence and to intensify that stimulated by C. albicans within the dose range from 100 to 300 J/m2 with a maximum at about 200 J/m2.

Animals↗