[Effect of antioxidant use in dietary therapy in patients with chronic athrofic hastritis].

In the 1-year double-blind placebo-controlled intervention trial, it was shown that daily supplementation of patients with gastric premalignant lesions (intestinal metaplasia, IM) with a complex, containing Ester-C with antioxidantsand (2100 mg of Ca-ascorbate + 340 mg of bioflavonoids), produced a sharp decrease of abnormally high ornithine decarboxylase activity in IM gastric mucosa that was accom panied by practically total IM regression in 11 of 18 (61%) patients.

[Potential cancer-protective effect of beta-carotene in experimental stomach carcinogenesis]. / Izuchenie potentsial'nogo kantseroprotektornogo deistviia beta-karotina pri éksperimental'nom gastrokantserogeneze.

Effect of beta-carotene on content of some metabolites of lipid peroxidation and activity of ornithine decarboxylase was studied in rat gastric mucosal membrane during gastric carcinogenesis developed after administration of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Intragastric administration of MNNG led to a significant increase in content of diene ketones and malonic dialdehyde in the gastric mucosal membrane within a day, while beta-carotene normalized or decreased considerably the MNNG produced accumulation of these lipid peroxidation products. In acute experiments with MNNG beta-carotene administered per os at a dose of 0.5 mg per animal did not affect the pronounced activation of ornithine decarboxylase in the gastric mucosal membrane. However, in chronic experiments with MNNG repeated administration of beta-carotene led to statistically significant decrease of the constitution-dependent enzymatic activation in the gastric mucosal membrane and to inhibition of locus formation with abnormally high activity of ornithine decarboxylase. The findings suggest that anticarcinogenic effect of the natural antioxidant beta-carotene was shown at the step of carcinogenesis promotion.

[The effect of beta-carotene on the dynamics of ornithine decarboxylase activity in atrophic mucous membranes and in stomach polyp tissue]. / Vliianie beta-karotina na dinamiku aktivnosti ornitindekarboksilazy v atroficheskoi slizistoi obolochke i v tkani polipov zheludka.

Activity of ornithine decarboxylase was significantly increased, reaching the maximal values in malignant gastric tissues, in mucosal membrane and polypous tissue of patients with atrophic gastritis as compared with normalcy. Any alterations in the enzymatic activity were not observed in the gastric mucosal membrane of 19 patients with atrophic gastritis within 3 weeks. At the same time, statistically significant decrease of the abnormal high activity of ornithine decarboxylase was detected in atrophic gastric mucosal membrane of 12 patients among 20 patients examined, which were treated with 20 mg of beta-carotene daily within 3 weeks; the enzyme activity was decreased also in polypous tissue of 5 patients in the group of 9 patients studied. Decrease in the ornithine decarboxylase activity after beta-carotene treatment involved improvement of the mucosal membrane state, where hemorrhage disappeared and inflammation reduced. Since the high activity of ornithine decarboxylase is related to promotion of cancerogenesis, beta-carotene appears to exhibit an anticarcinogenic effect as it decreases the enzymatic activity in gastric mucosal membrane.

[The role of endogenous and exogenous factors in the etiology of skin melanoma]. / Rol' nekotorykh éndogennykh i ékzogennykh faktorov v étiologii melanomy kozhi.

The results of case-control study of skin melanoma carried out in Moscow are presented. They point to considerable influence of endogenous factors on the relative risk of melanoma. The risk of melanoma is increased by such factors as light color of the skin, presence of freckles and moles. Exposure to UV-radiation raised the risk of melanoma, however, after relevant adjustment for the said factors relative risk was reduced. Consumption of greens and high blood levels of alpha-tocopherol significantly decreased the risk of melanoma. Female users of oral contraceptives had significantly lower risk of skin melanoma.

[Functional deficiency of riboflavin in patients with melanoma]. / Funktsional'naia nedostatochnost' riboflavina u bol'nykh melanomoi.

Preliminary data on the functional riboflavin deficiency in patients with malignant skin melanoma are discussed. In 50% of 36 patients with skin melanoma the glutathione reductase activation coefficient was higher than 1.21 and in 28% of the patients--above 1.31. Oral administration of high doses of riboflavin normalized the riboflavin status.

[Riboflavin supply of the Kara-Kalpak ASSr population with pathologic changes of the esophageal mucosa]. / Obespechennost' riboflavinom zhitelei Karakalpakskoi ASSR s patologicheskimi izmeneniiami slizistoi pishchevoda.

Riboflavin supply was studied in 164 adult inhabitants of the Kara-Kalpak ASSR where a high incidence of cancer of the esophagus and precancer changes of the esophageal mucosa were recorded. Endoscopy was used to investigate the morphological picture of the esophageal mucosa. A standard method for evaluation of the activation coefficient (AC) of erythrocytic glutathion-reductase (EC1.6.4.2) in the presence of FAD was used as a criterion of the body supply with riboflavin. Pronounced riboflavin deficiency (AC greater than or equal to 1.30) and B2 hypovitaminosis (AC = 1.20-1.29) were observed in 17 and 23% of the cases, respectively. Statistical analysis of the data obtained evidences that insufficient supply with riboflavin is recorded, on an average, 3.5-5.5 times more frequently in subjects with pronounced catarrhal esophagitis, combined with or without leukoplakia, than in the control group of subjects with out pronounced changes in the esophageal mucosa. No positive statistically significant association between low supply of the body with riboflavin and atrophic esophagitis has been established.

[Anticarcinogenic action of vitamins PP and B6 in the natulan initiation of malignant growth in mice]. / Antikantserogennoe deistvie vitaminov PP i B6 pri initsiatsii natulanom zlokachestvennogo rosta u myshei.

Parenteral administration of vitamins PP and B6 at the initiation stage of natulan-induced carcinogenesis was shown to significantly inhibit formation of lung adenomas. The preventive effect was found to depend on treatment schedule. Biochemical aspects of anticarcinogenic action of the vitamins require special investigation.

[Relationship between the character of pathological changes in the esophageal mucosa and deficiency of several vitamins in a population with high incidence of esophageal cancer]. / Sviaz' mezhdu kharakterom patologicheskikh izmenenii slizistoi obolochki pishchevoda i defitsitom nekotorykh vitaminov v populiatsii s vysokoi chastotoi raka pishchevoda.

A comparative study of the esophageal mucosa versus vitamin status in the adult male population of Muinak District of the Karakalpak ASSR, characterized by high incidence of esophageal cancer, established a significantly high frequency of chronic esophagitis. The differential evaluation of different pathologies of the esophageal mucosa suggested a link between catarrhal and erosive esophagitis and vitamin B2 deficiency and atrophic esophagitis and vitamin A deficit.

[Protective action of nicotinamide and pyridoxine on the initiation stage of carcinogenesis induced in mice by procarbazine]. / Zashchitnoe deistvie nikotinamida i piridoksina na stadii initsiatsii kantserogeneza, vyzvvaemogo u myshei prokarbazinom.

It is shown that at the initiating stage of procarbazine carcinogenesis in F1 female mice the parenteral administration of nicotinamide or pyridoxine results in a significant decrease in the lung adenoma rate from 77% to 18 or 46%, respectively. Pyridoxal, pyridoxal-5'-phosphate and L-penicillamine did not influence the lung adenoma frequency.

[Ascorbigen and its derivatives--depot preparations of ascorbic acid]. / Askorbigen i ego proizvodnye--depo-formy askorbinoboi kisloty.

New derivatives of 2-C-/(indolyl-3)methyl/-beta-L-threo-L-glycero-3-hexulofuranosono- 1,4-lactone, vis. 1'-ethylascorbigen, 1'-benzylascorbigen and 1',2'-dimethyl-5'-methoxyascorbigen were obtained. In aquous solutions at physiological temperature and pH values ascorbigens disintegrate rather rapidly to yield L-ascorbic acid, the rate of the latter's formation depending on the substituent in the indole nucleus and increasing with growth of pH and temperature. Intraperitoneal injection of 1'-methylascorbigen to mice leads to steady rise of L-ascorbic acid level in blood plasma.

[Effect of methylglyoxal bis(guanylhydrazone) in combination with antifolic acid preparations on the biochemical indices and growth of Pliss lymphosarcoma in rats]. / Vliianie metilglioksal'-bis(guanilgidrazona) v kombinatsii s antifolievymi preparatami na nekotorye biokhimicheskie pokazateli i rost limfosarkomy Plissa u krys.

It was shown in experiments with Pliss' lymphosarcoma in rats that antifolates--cis-2,5-bis (aminohydroxymethyl)-piperazine-3,6-dione and methotrexate--cause tumor cell spermidine level to drop. Also, treatment with antifolates prevented the undesirable accumulation of S-adenosylmethionine in tumor cells induced by methyl-glyoxal-bis (guanylhydrazone) which inhibits polyamine biosynthesis. In chemotherapeutic experiments with rat lymphosarcoma, antifolates markedly potentiated the antitumor effect of methylglyoxal-bis (guanylhydrazone). The data suggest that the combination of polyamine biosynthesis inhibitors such as methylglyoxal-bis (guanylhydrazone) and alpha-difluoromethylornithine and antifolates may be useful in tumor chemotherapy.

[Regression of the Pliss lymphosarcoma in rats and biochemical indices in hypovitaminosis A]. / Regressiia limfosarkomy Plissa u krys i nekotorye biokhimicheskie pokazateli v usloviiakh gipovitaminoza A.

It has been shown that in rats with alimentary hypovitaminosis A, with a sufficiently pronounced decrease in the content of free retinol in blood serum (below 140 ng/ml) and in the liver tissue (below 360 ng/g), there is a complete regression of Pliss's lymphosarcoma. Under the conditions indicated, retinoic acid, in contradistinction to retinol, does not promote the tumor growth. A relative and absolute reduction in blood plasma of the essential amino acids, arginine, methionine and lysine, might be one of the reasons for tumor regression under hypovitaminosis A.

[Effect of L-ascorbic and D-isoascorbic acids on induced formation of tyrosine aminotransferase in rat liver]. / Vliianie L-askorbinoovoi i D-izoaskorbinovoi kislot na indutsirovannoe obrazovanie tirozin-aminotransferazy v pecheni krys.

Administration of ascorbic acid at moderate doses/0.05-0.1 g per kg of body mass/was shown to induce tyrosine transaminase in liver tissue of intact rats. The enzyme induction depended on the state of adrenal glands and was inhibited by actinomycin D. As distinct from the native form of L-ascorbic acid moderate doses of D-isoascorbic acid did not induce the enzyme in rat liver tissue; these data suggest the relative biological inactivity of D-isoascorbic acid.

[Role of the components in the methylation system in the cobalamin-dependent gentamycin biosynthesis by a Micromonospora purpurea culture]. / Issledovanie roli nekotorykh komponentov sistemy metilirovaniia v kobalaminzavisimom biosinteze gentamitsina kul'turoi Micromonospora purpurea.

It was found that under conditions of a short-term cultivation of the Co-deficient mycelium of M. purpurea var. violaces 1935 in the synthetic medium the level of gentamicin biosynthesis increased on the average by 2--2.5 times when cyancobalamine, methylcobalamine, L-methionine or L-serine were added to the medium. Glycine and H2-pholate increased the gentamicin yield on the average by 1.5--1.8 times. When the concentration of L-methionine in the medium was optimal, production of gentamicin by the Co-deficient mycelium markedly increased on addition of extra amounts of cyancobalamine into the medium. An analogous high level of gentamicin biosynthesis was observed in the absence of L-methionine, when combinations of H2-pholate and L-serine or cyancobalamine, H2-pholate and glycine were added to the medium. The data of the study indicate that the pholate-dependent neogenesis of -CH3 group and the methyl-B12-dependent resynthesis of L-methionine play an important functional role in biosynthesis of gentamicin.