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Biomedical subjects

L M Berstein

Publications and source records attributed to L M Berstein.

At least 73 records · Page 4Linked to original sources
PubMed1989

Fetal macrosomia and sex differences in the influence of modifying factors on transplacental carcinogenesis.

Differences in cancer frequency between men and women are well known. Sexual dimorphism is also observed in the development of some experimental tumours, including those induced transplacentally. Differences in the production and binding of sex hormones by target tissues are evidently not the only cause of sexual dichotomy in the action of modifying factors on transplacental carcinogenesis. In our experiments, the average weight of newborn rats treated with glucose during intrauterine life from day 7 to 20 of gestation exceeded that of control animals, and rats exposed transplacentally to N-methyl-N-nitrosourea (MNU) on day 21 of gestation in combination with glucose (beginning from day 7 of prenatal life to 1.5 months after delivery) had a significantly increased tumour frequency. In males, there was an increased frequency of neoplasms of the nervous system and kidneys, which are typical transplacental carcinogenic effects of MNU; however, in females, neoplasms were induced in other organs and tissues, mainly the mammary gland and pituitary body. Thus, fetal macrosomia acts as a modifying factor in transplacental carcinogenesis also by determining the tumour spectrum in females and males and not only in increasing tumour frequency. The possible causes of these differences and perspectives for further research are discussed.

Animals↗
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

Preliminary evidence on metabolic rehabilitation of cancer patients.

Pathways of metabolic rehabilitation of cancer patients are discussed. The effectiveness of a long-term carbohydrate, fat and cholesterol restricted diet and hypolipidemic and antidiabetic medication for breast, gastric and colorectal cancers was demonstrated for the first time. The results of gastro-intestinal cancer treatment were especially encouraging. Metabolic rehabilitation chiefly resulted in a lower frequency of metastatic spread. Also, its effect was seen in a rarer primary multiple tumor development. The results make a case for further development of investigations in normalizing fat-carbohydrate metabolism as adjuvant therapy for cancer in postoperative period.

Adult↗
PubMed1984

Glucose consumption, newborn weight and nitrosomethylurea transplacental carcinogenesis in rats.

This study used rats bred at the Petrov Research Institute of Oncology. On the 21st day of pregnancy N-nitrosomethylurea (NMU) (20 mg/kg) was administered to the animals intraperitoneally. From the 7th day of pregnancy experimental rats were treated with 10% glucose solution instead of drinking water, and during 1.5 months after delivery the rats of this group and their progeny received 5% glucose solution. The present work has revealed an increase of fetal weight in pregnant rats treated with glucose. A significant increase of tumor frequency was detected in the progeny of these rats. In the male progeny, tumors of the nervous system and kidneys, typical for NMU, predominated and in females, tumors of other organs and tissues, particularly the mammary gland, pituitary body and hemopoietic system, predominated. This paper discusses a possible mechanism of the modifying effect of glucose on transplacental carcinogenic action of NMU.

Animals↗
PubMed1982

Metabolic immunodepression and metabolic immunotherapy: an attempt of improvement in immunologic response in breast cancer patients by correction of metabolic disturbances.

The effects of administration of phenformin and clofibrate to 32 breast cancer patients who underwent radical mastectomy and suffered from hormonal metabolic disturbances involving a decline in immunologic response were investigated. It was demonstrated that treatment with these drugs during 2--7 months results in an improvement in metabolic parameters and delayed hypersensitivity reaction to DNCB, tuberculin and candidin (75.5% of cases), an increase in T lymphocyte count (56.3%) and an improvement of the reaction of lymphocyte blast transformation (66.6%). The improvement in the immunologic status of the patients persisted for 6--8 weeks after the stoppage of phenformin administration; a gradual decline in immunologic response and return to the original level were recorded 4--6 months after stoppage and phenformin therapy. The effect of clofibrate on metabolic and immunologic parameters did not manifest itself as soon as 6--8 weeks after stoppage. Elimination of metabolic immunodepression, which gradually develops in the course of normal ageing and tumor process, should be the main objective of metabolic immunotherapy. To this end, therapeutic means, other than phenformin and clofibrate, may be used provided they exert the same effects on carbohydrate-fat metabolism. The desirability of study of the effects of a long-term course of drugs of this kind on the therapy of cancer patients is discussed.

Age Factors↗
PubMed1982

Effects of misclerone (clofibrate) on dimethylhydrazine-induced intestinal carcinogenesis in rats.

Intestinal tumors were induced by treatment with dimethylhydrazine (DMH) (14 mg with reference to base/kg body weight, weekly, s.c., for 20 weeks) in male rats supplied by Rappolovo Animal Farm. Some of the animals received 25 mg/day of misclerone (clofibrate) per os, 5 times a week. Clofibrate treatment did not affect the frequency of tumors of the large and small intestine but was followed by a significant decrease in the number of large- and medium-size tumors. The animals which had received clofibrate beginning from 10 days before the first injection of DMH revealed a relatively greater fraction of exophytic intestinal tumors and less invasion of the intestinal wall as compared with the animals treated with DMH alone. Possible mechanisms of the effect of clofibrate are discussed.

Animals↗
PubMed1981

Peculiarities of hyperlipidaemia in tumour patients.

The study group included 684 cases: 258 patients with breast carcinoma, 113 males with lung cancer, 42 patients with rectal tumours, 42 patients with stomach tumours, 59 patients with fibroadenomatosis, and 170 healthy subjects of varying age (male and female). A relatively high blood triglyceride level was found in patients with breast, lung, rectal (females), and stomach (female) tumours. The blood concentration of high-density lipoprotein-cholesterol in patients with breast, lung, and stomach (female) tumours was relatively low. The elimination of tumour (breast carcinoma) did not lead to significant changes in lipid metabolism. There was no correlation between degree of lipidaemia and stage of tumour progression except in the cases of rectal cancer. Preliminary results are presented on the tentative classification of hyperlipoproteinaemia in tumour patients, using the lipid concentration threshold values advocated by Carlson et al. (1977); an increased frequency of Type IV hyperlipoproteinaemia proved to be the most characteristic feature of tumour patients. The results are discussed in terms of the concept of the importance of lipid metabolic disturbances, primarily those due to ageing, in the genesis of the syndrome of "cancerophilia" (predisposition to cancer).

Adult↗
PubMed1980

The effect of physiological doses of thyroxine on the level of cyclic adenosine-3',5'-monophosphate in pituitary and anterior hypothalamus of male rats of different age.

The levels of cAMP in the pituitary and anterior hypothalamus were determined by competitive binding to protein in male rats aged 2--2.5, 6--8 and 14--18 months. The lowest level of cAMP both in the pituitary and anterior hypothalamus (1.05 +/- 0.17 and 0.85 +/- 0.23 pM) (per mg wet weight, respectively) was found in 6--8 month-old rats. Administration of T4 (2 micrograms/100 g body weight, for 8 days) was followed by a decrease in cAMP level in the pituitary of 14--18 month-old animals, which was not the case with younger rats. The obtained results agree with the earlier observation that the threshold to homeostatic suppression in the hypothalamus-pituitary-thyroid system of rats decreases with aging. It is suggested that cAMP system contributes to the mechanism of changes in hypothalamic threshold and its pharmacological correction.

Aging↗
PubMed1978

Effect of parathyroid hormone and insulin on extracellular cyclic adenosine-3',5'-monophosphate in patients with benign and malignant breast tumors.

Basal excretion of cyclic adenosine monophosphate (cAMP) and its basal level in blood plasma in breast cancer (BC) patients and those with fibroadenomatosis did not differ essentially. However, intravenous injection of parathyroid hormone (100 U) and insulin (0.08 U/kg body weight) was followed by a much less rise in urine-cAMP excretion and blood-cAMP levels in BC patients than in benign process in mammary gland. A substantial correlation between changes in plasma cAMP level and the degree of insulin-induced hypoglycemia was not observed. There was a negative correlation between reponse to parathyroid hormone and insulin and body overweight in BC patients. It was suggested that body fat content may influence the peculiarities of metabolism of extracellular cAMP in cancer patients considerably.

Adipose Tissue↗
PubMed1978

Inhibition of DMBA-induced carcinogenesis by phenformin in the mammary gland of rats.

It is shown that daily oral administration of 5--10 mg of an antidiabetic biguanide-phenformin (phenethyl-biguanide) for 2.5--5 months suppressed DMBA-induced mammary tumour development in rats considerably. Phenformin-treated rats revealed-a tendency towards a decrease in blood insulin level (radioimmunoassay). The obtained data are regarded as additional evidence for the proposed existence of the same metabolic background of diseases of compensation, i.e. adult-onset diabetes, artherosclerosis and cancer, and suggest studies on possible antitumour effect of phenformin in man.

9,10-Dimethyl-1,2-benzanthracene↗