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N I Vol'fson

Publications and source records attributed to N I Vol'fson.

At least 19 recordsLinked to original sources
PubMed1988

[Comparative evaluation of the sensitivity to the carcinogenic action of N-methyl-N'-nitro-N-nitrosoguanidine of the epithelium of endophytic adenomatous-hyperplastic structures and of the epithelium of the gastric glands in rats].

The experiments carried on 107 rats have shown that the sensitivity of the epithelium of experimental adenomatous diverticuli of the stomach to the action of N-methyl-N'-nitro-N-nitrosoguanidine is lower than that of the gland epithelium of the organ.

Adenocarcinoma↗
PubMed1988

[Stomach tumors in rats induced by a single administration of N-methyl-N-nitro-N-nitrosoguanidine and N-methyl-N-nitrosourea].

The pathologic characteristics of gastric tumors induced by single injections of N-methyl-N'-nitro-N-nitrosoguanidine (15 mg) solution and N-methyl-N-nitrosourea (10 mg) solution in 0.1 ml dimethylformamide were studied in 23 noninbred rats. The chemicals were injected into the antropyloric segment of the stomach. By months 11-15, specific changes in the glandular epithelium had developed at that site in 20 rats: dysplasia--in 6, precancer--7, and adenocarcinoma in 7 animals. Also, there were papillomas (6), squamous cell carcinoma (3), precancer and sarcoma (4) in various segments of the organ.

Adenocarcinoma↗
PubMed1986

[Effect of vinblastine on experimental stomach carcinogenesis].

The experiments on inbred male rats have been carried out to estimate the effect of parenteral vinblastine, an inhibitor of catecholamine axoplasmatic transport, on gastric tumour growth induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) added to drinking water. The maximum tolerance dose of vinblastine was determined in subchronic experiments on 30 rats (0.25 mg/kg subcutaneously, once per week). Chronic experiments with combined introductions of MNNG and vinblastine were performed on 70 rats. Vinblastine was shown to inhibit carcinogenesis on "intestinization" stake and to decrease three-fold the incidence of gastric adenocarcinomas. Vinblastine-induced changes in the behaviour of animals reflect the decreased activity of central adrenergic processes. The role of catecholamines in the mechanisms of specific action of chemical carcinogens is discussed.

Adenocarcinoma↗
PubMed1985

[Changes in the pepsin activity of the gastric mucosa of rats in the early stages of carcinogenesis].

The paper discusses changes occurring in the enzymatic activity of pepsin in rat's gastric mucosa at early stages of carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine treatment with drinking water. All doses (5, 15, 45, 75 and 150 mg/l) proved to be effective and inhibited pepsinogen biosynthesis considerably. Particularly sharp drops in the enzyme activity were observed with the concentrations of 45, 75 and 150 mg/l. The effect was reversible at early stages, particularly, at low concentrations of the agent. It is suggested that the critical point reached by pepsinogen synthesis in gastric mucosa carcinogenesis, which is manifested by the enzyme synthesis resumption on treatment being suspended, may be regarded as the check point in the course of neoplastic development.

Animals↗
PubMed1981

[Biochemical changes in the glandular part of the rat stomach as affected by N-methyl-N'-nitro-N-nitrosoguanidine].

Biochemical changes in the stomach mucous membrane of rats treated with N-methyl-N-nitro-N-nitrosoguanidine (MNNG) were studied. Carcinogenesis was shown to involve considerable changes in gastric mucous membrane, e. g. disorders in biosynthesis of isoforms of pepsinogen-pepsin. Their level and proteolytic activity are gradually declined. This effect can be reversed at an early stage of treatment and is persistent in advanced tumors of glandular part of rat stomach.

Animals↗
PubMed1980

[Systemic blood diseases in inbred mouse strain CC57W].

In "low cancer" CC57W mouse line studied over a period of 1944--1969 spontaneous leukemias occurred in 0.4--6.8%. During 1971--1976 the frequency of spontaneous leukemias amounted to 33%. Morbid anatomic and hematologic studies showed that aleukemic and subleukemic forms of chronic generalized reticulosarcomatosis with predominant affection of the lymphatic system accounted for the overwhelming majority of systemic diseases of the blood. Electron microscopy revealed virus-like type C particles in the cells of the affected organs.

Animals↗
PubMed1979

[Histogenesis of gastric hyperplastic changes in mice].

In experiments on CC57W mice fed carcinogenic substances the author has studied some hyperplastic changes arising in the stomach of 157 mice. In all these cases the original elements participating in the development of pathological structures: micropolyps, adenomatous diverticula, polypoid reactive adenomatous-connective tissue growths were found to be either neck cambial elements or retaining the cambial activity cell elements of deep-seated glandular portions, as well as of different portions of the lining and gastric pit epithelium.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1979

[Possible carcinogenic action of chromogen dicarboxidine].

In chronic experiments on 208 rats and 127 mice tne carcinogenic activity of dicarboxidine was examined. The substance was administered percutaneously and by leeding it during two years in the dosage: 20 mg -- 45 mg for rats, 3 mg -- 4 mg for mice. In late terms of the experiment (following one year and a half) the rats developed sarcomas at the site of its injection as well as tumors of other organs, including the urinary bladder. The substance was found to render no appreciable effect on mice. A conclusion is drawn on an insignificant carcinogenic activity of the substance under test, taking into account the late terms of tumors appearance and the induction of tumors only in one species of animals.

Animals↗
PubMed1976

[The genesis of experimental granulosa cell tumors of the ovaries].

Ovaries and their tumors were investigated in virgin female mice (78 control and 252 experimental) of line A and CC57W (aged-from 1 to 1 1/2 months) in the experiments with intravaginal application of polyurethan, 7,12-dimethylbenz (a) anthracene, 8-oxychinoline, synoestrol. It was demonstrated that only granulosa elements of atresic follicles are involved in the process of blastomogenesis. Theca-tissue showed no appreciable participation in proliferative processes. Totally, pretumor changes were noted in 56 cases, folliculomas or pathological changes morphologically identical to microfolliculomas- in 26 cases.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1975

[The carcinogenic action of 1,3-diiminoisoindolin (phthalogen)].

In experiments on mice CC57 and rats (the Rappolovo nursery) the effect of continuous phthalogen injections (from 325 to 467 days) was studied. 36 rats and 99 mice survived the terms of appearance of the first tumors. Average total doses of the drug in subcutaneous injections in the experiments on rats -321-630 mg, while in the experiments on mice - 3,5-5,21 mg, in cutaneous applications - 31 mg per mouse. In the experiments with subcutaneous phthalogen injections tumors arose in 65%, including leucoses - in 54%. These figures exceed nearly twice the corresponding control values. Pulmonary tumors (adenocarcinoma and sarcoma in four cases) were observed at the site of the drug injection. In the experiments on rats sarcomas were found in 9 cases at the site of the injection of the substance. In one rat renal adenocarcinoma developed. The data obtained indicate a weak carcinogenic action of phthalogen.

Animals↗