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Biomedical subjects

I G Kovaleva

Publications and source records attributed to I G Kovaleva.

At least 19 recordsLinked to original sources
PubMed2002

Effect of hyperlipidemia on functional activity of peritoneal macrophages in CBA and C57Bl/6 mice.

The effect of experimental hyperlipidemia on functional activity of macrophages was studied in CBA and C57Bl/6 mice resistant and sensitive to the formation of aorta lesions, respectively. Two-month atherogenic diet increased the content of cholesterol in the serum and cells of peritoneal exudate in mice of both strains. In parallel, production of nitrites and 5'-nucleotidase activity in peritoneal macrophages increased, while parameters of phagocytosis, pinocytosis, and NBT test remained unchanged. Changes in the state of macrophages can be explained by increased cholesterol content. The absence of differences in functional activity of macrophages in CBA and C57Bl/6 mice indicates that the observed shifts are insignificant for the development of fatty streaks in the aorta.

Animals↗
PubMed2000

Effect of hyperlipidemia on thymocyte sensitivity to apoptosis in CBA and C57Bl/6 mice.

Effects of experimental hyperlipidemia on apoptosis and proliferation of thymocytes in response to mitogens were studied in CBA and C57Bl/6 mice. The concentrations of cholesterol in the serum and thymocyte membranes increased in both mouse strains. Spontaneous and dexamethasone-induced apoptosis in vitro and the proliferative response to phytohemagglutinin and concanavalin A were enhanced in thymocytes from C57Bl/6 mice and suppressed in cells from CBA mice. These data suggest opposite reactions of thymocyte to increased serum cholesterol concentration in these two strains, associated with stimulation and suppression of cell activity.

Animals↗
PubMed1994

[Management of patients after reconstructive and restorative surgery of the large intestine].

Reconstructive-restorative operations were conducted on the large intestine in 932 patients. Means of optimization of treatment in the early postoperative period in elderly and old-aged patients, who often have concomitant diseases, must be searched for. The dynamics of energy consumption in the early postoperative period was studied in 15 patients. Considerable effectiveness of complex diet including proteins was established during elaboration of individual dosed feeding. The immune status was studied in dynamics in 38 patients; immunomodulation agents lead in most cases to restoration of the reduced immunity indices or have a stabilizing effect on them when used both as a preventive and as a therapeutic measure. Percutaneous electrostimulation in the early postoperative period proved to be highly effective in arresting the pain syndrome, removal of functional intestinal paresis and reflex ischuria.

Adjuvants, Immunologic↗
PubMed1992

[The assessment of the hormonal sensitivity of tumors of the large intestine in the adenylate cyclase test].

Sensitivity of 142 human large bowel malignancies to gastroenteropancreatic hormones (VIP, glucagon and pentogastrin) and calcitonin was studied using in vitro adenylate cyclase reaction of tumor. At least 40-55% of the tumors proved hormone sensitive. Heteroresponse (reaction to calcitonin) was most characteristic for colonic tumors whereas weak reaction to VIP and glucagon-for rectal neoplasms. A certain relationship was established between adenylate cyclase reaction to hormone stimulation, on the one hand, and peculiarities of tumor (degree of cell differentiation) and the body (gender), on the other. In patients who survived over 4 years, tumor adenylate cyclase had initially been more sensitive to hormone stimulation than in those who died over that period. It is concluded that tumor adenylate cyclase reaction to hormone stimulation is quite a reliable test for evaluating hormone sensitivity of large bowel tumors and, possibly, for choosing hormonal therapy.

Adenocarcinoma↗
PubMed1992

[The role of cholesterol in activating lipid peroxidation in platelets].

The relationship between the cholesterol (Ch) content and the concentration of lipid peroxidation (LPO) products in activated platelets and the effect of these parameters on the structure-function characteristics of platelet membranes were studied. It was found that esterified Ch activates free radical processes occurring in platelets. Nonesterified Ch does not induce the production of primary products of LPO (dienoic conjugates) but promotes the accumulation of a secondary LPO metabolite, malonic dialdehyde, this reaction being mediated via indirect mechanisms. The higher (in comparison with normal) orderliness and orientation of membranes in platelets reflect the increase in the concentration of dienoic conjugates and nonesterified Ch. The observed differences in the aggregability of platelets are due to the changes in the Ch content as well as to the "rigidity" of blood platelets.

Blood Platelets↗
PubMed1990

[Various indicators of vascular-thrombocytic hemostasis and blood rheology in ergometrine tests].

The function of platelets and erythrocytes and content of Willebrand's factor in the plasma from 45 patients with exercise-induced or spontaneous angina pectoris were examined before and after ergometrine, 0.1 mg. The patients with a negative ergometrine response showed a lower platelet sensitivity to all the aggregation inductors used in vitro, spontaneous platelet aggregation being absent. The function of erythrocytes and plasma levels of Willebrand's factor remained unchanged. The patients with a significant ischemic response to ergometrine exhibited platelet activation attended by the release of granule contents and formation of blood circulating platelet microaggregates. Concurrently, there was a decrease in erythrocyte deformability, as well as spontaneous blood red cell aggregation, the plasma levels of Willebrand's factor were increased 1.5-2-fold.

Aged↗
PubMed1989

Peculiarities of hormonal regulation of adenylate cyclase and lipid composition in colonic and rectal tumors.

Peculiarities in hormonal regulation of adenylate cyclase (AC) were studied in large bowel tumors to establish criteria of their hormonal dependence. The investigation showed a diminished basal activity of AC matched by decreased response to sodium fluoride, glucagon, and vasoactive intestinal peptide (VIP) in tumors as compared with normal intestinal mucosa. Some cases revealed an increased response of AC to a nonspecific ("inappropriate") stimulator--calcitonin. This was rather typical of colonic tumors while a diminished response to specific ("appropriate") stimulation by VIP and glucagon was more frequent in rectal cancer. The results showed a relationship between hormonal regulation of AC activity and lipid composition of tumor tissue, thus suggesting the possibility of influencing the hormone dependence of intestinal tumors by drugs used to eliminate disturbance of fat-carbohydrate metabolism.

Adenylyl Cyclases↗
PubMed1988

[Characteristics of the hormonal metabolic status of patients with colonic and rectal cancer].

Peculiarities of hormone-metabolic status in patients with cancer of the rectum and colon consist of 1) symptoms of cancrophilia, 2) disturbances of enteric endocrine system and 3) properties of the tumour tissue, determining first of all its hormone sensitivity. Determination of steroid hormone (estrogens and progesterone) receptors does not appear a sufficiently informative criterion of colorectal cancer tissue hormone sensitivity; the adenylate cyclase reaction to the hormonal stimulators is more informative in this respect. The data obtained may be useful in the working out of adjuvant therapy methods in cancer of colon and rectum (including hormonotherapy and metabolic rehabilitation).

Adult↗
PubMed1986

[Cholesterol and phospholipid content of cells sensitive and resistant to ethidium bromide and its alteration in resistant cells as affected by methyltestosterone].

The content of cholesterol (Chl) and phospholipids (Phl) in cell lines L and CHO-K1, sensitive and resistant to the toxic action of ethidium bromide, has been studied. EB-resistant cells were shown to have lower amounts of Chl and Phl, and the ratio Chl/Phl in these cells was decreased too. EB-resistant cells, grown in serum-free medium, have dramatically decreased contents of Chl, while compared with the cells growing with serum. Treatment of EB-resistant cells with methyltestosterone in concentration of 3 X 10(-7) M caused the increase in Chl and Phl contents, thus approximating these indices to those of EB-sensitive ones.

Animals↗
PubMed1985

[Content of cyclic nucleotides, cholesterol and phospholipids in tumors of the large intestine].

Tissues from tumor and normal intestine were examined in 44 patients suffering from colonic and rectal cancer. The study established elevated levels of cholesterol (chiefly, cholesterol esters) and phospholipids, as compared with normal tissue. Two groups were identified among the cancer patients on the basis of the ratio of K = (Formula: see text). Cases with a relatively low value of K revealed higher levels of body fat and hyperlipidemia. That was matched by relatively higher concentrations of cholesterol and its esters, but not phospholipids, in tumor tissue, as compared with normal one. The relationship between cyclic nucleotide metabolism disorders in neoplastic tissue and lipid metabolism in cancer patients is discussed.

Adenocarcinoma↗
PubMed1985

[Cyclic adenosine monophosphate content in the lymphocytes of cancer patients].

Examinations have been carried out on 83 cancer patients (aged 34-72), 24 patients with atherosclerosis (aged 38-68) and 34 healthy persons (aged 20-69). The cAMP concentration decrease with age in lymphocytes of healthy persons is confirmed. This index in patients with lung carcinoma, breast carcinoma in remission and in patients with atherosclerosis was identical with that of healthy persons, but in patients with breast and corpus uteri carcinomas without metastases it was higher than in healthy persons of the similar age. The amount of cAMP in lymphocytes is compared with the magnitude of the blast transformation and with the amount of cholesterol in blood and lymphocytes in examined persons. The cAMP level in lymphocytes is observed to increase in the process of hyperlipidemia disappearance in cancer patients and in those with atherosclerosis.

Adult↗
PubMed1985

[Age-related changes in adenylate cyclase activity, lipid composition and lipid peroxidation in rat intestinal mucosa: comparison with the frequency of spontaneous tumors].

The study used 3, 7, 16 and 22 month-old male rats bred at the animal farm of the Institute. Identical age-related changes were established in the level of free cholesterol, its esters, free cholesterol/phospholipids and sphingomyelin/lecithin ratios in ascending and descending colon mucosa. Unlike descending colon mucosa, the basal and hormone-stimulating activity of adenylate cyclase and rate of lipid peroxidation in the mucosa of the ascending colon of 22 month-old animals were lower than in 16 month-old rats. The results are compared with the available data on the predominant localization of spontaneous tumors in the proximal (ascending) part of rat's intestine.

Adenylyl Cyclases↗
PubMed1985

[Effect of hypolipidemic preparations on basal and stimulated adenylate cyclase activity in tumor cells].

A study was made of the action of the antidiabetic biguanide phenformin, clofibrate and the phospholipid drug Essentiale on the basal and adrenaline-stimulated activity of adenylate cyclase in Ehrlich's ascites carcinoma cells. All the drugs under study potentiated the hormone-stimulated activity of adenylate cyclase. Unlike phenformin and Essentiale, clofibrate did not exert any effect on the basal activity of adenylate cyclase. On the other hand, certain differences were revealed in changes of the lipid content of tumor cells during application of the drugs in question. Stimulation of adenylate cyclase activity by hypolipidemic drugs is regarded as a promising approach to the goal-oriented changing of hormonal sensitivity of tumor cells.

Adenylyl Cyclases↗
PubMed1982

[Summary insulin-like activity of the blood serum in breast cancer and in specific age-related pathology].

Total insulin-like activity (ILA) was evaluated by biological testing blood serum on the basis of stimulation of glycogen synthesis in rat diaphragm in vivo. Glucose loading was followed by an increase in ILA and radioimmune insulin (RII) levels both in patients with breast fibroadenomatosis and healthy controls. However, the patients revealed an increased RII response matched by absence of ILA response, while the basal ILA was three times that in healthy controls. An elevated basal level of ILA was also observed in patients with coronary atherosclerosis and mental depression. Enhanced hyperinsulinism due to RII complementary factors, capable of insulin-like activity, may prove to be a factor in specific age-associated pathology (cancer, atherosclerosis, mental depression).

Adenofibroma↗