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Biomedical subjects

S N Fedorov

Publications and source records attributed to S N Fedorov.

At least 19 recordsLinked to original sources
PubMed1995

Biological activity of disulfated polyhydroxysteroids from the Pacific brittle star Ophiopholis aculeata.

The action of (20R)-cholesta-5,25-diene-3 alpha, 4 beta, 21-triol 3,21-disulfate and its 25,26-dihydroanalog from the Pacific brittle star Ophiopholis aculeata was studied on mouse cancer cells, lymphocytes and erythrocytes. The cytotoxic and hemolytic effects were not observed for both steroids at the wide range of concentrations. Both steroids inhibited 3H-Thymidine (but not 3H-Uridine) incorporation into Ehrlich carcinoma cells. It was the first time shown that some sulfated marine polyhydroxylated steroids stimulate the influx of Ca2+ into cells. (20R)-Cholesta-5,25-diene-3 alpha, 4 beta, 21-triol 3,21-disulfate was two times more active than its 25,26-dihydro-analog.

Animals↗
PubMed1989

[Proto-oncogene expression in the organs of intact adult rats].

The study is concerned with the expression of src, sis, fos, myc, Ha-ras, Ki-ras, N-ras, mos, and abl proto-oncogenes in the brain, heart, liver, kidneys, lung, stomach, cross-striated muscle cells and in leukocytes. Some of these genes are shown to be actively transcribed in adult intact rats. Their expression depends on the tissue specificity. Most of the investigated proto-oncogenes are expressed in the liver and kidney weakly, and in the brain and heart--more strongly. A correlation is observed between fos and Ha-ras proto-oncogenes' expression in organs of intact rats.

Animals↗
PubMed1989

[Polymorphism of restriction fragments of the Ha-ras-1 protooncogene in patients with carcinoma and ulcers of the stomach].

Ha-ras restriction fragments' length polymorphism (RFLP) in white blood cells and stomach tissues from patients with carcinoma and ulcer of the stomach was examined. Genomic DNAs were digested with Xho I, Pvu II, Pst I, Msp I, Bcn I, Mva I, Bsp RI. No Ha-ras-1 polymorphic variants specifically associated with the cancer disease were detected. RFLP of the 3'-noncoding sequence of c-Ha-ras-1 gene had got features of the definite human population. The cells forming the tissue were examined and individual peculiarity of the methylated residues disposition seemed to influence RFLP of the 5'-noncoding sequence of c-Ha-ras-1.

DNA↗
PubMed1989

[Proto-oncogene expression in human carcinomas of the stomach and in the gastric mucosa of rats exposed to N-methyl-N'-nitro-N-nitrosoguanidine-induced gastric carcinogenesis].

The expression of c-Ha-ras-1, Ki-ras, N-ras, abl, src, fos and myc protooncogenes was analyzed in 13 cases of human gastric carcinomas. The transcriptional activity of both fos and myc protooncogenes was found to be disturbed in 47% and 42% of cases, respectively. An overexpression of fos protooncogenes as well as an appearance in some cases of atypical foc-mRNA transcripts were established. Only an elevation of the number of myc mRNA copies was observed. In one patient with gastric carcinoma a c-Ha-ras-1 overexpression was detected due to its amplification both in tumour tissues and in regional metastasis. The expression of other protooncogenes under investigation was similar to those found in normal gastric mucose. In addition, no differences in expression in protooncogenes mentioned above plus sis protooncogene were established in unchanged, premalignant and malignant stomach tissues in the course of N-methyl-N'-nitro-N-nitrosoguanidin-induced carcinogenesis.

Animals↗
PubMed1987

[Joint amplification of c-myc and c-Ha-ras oncogenes in human breast and thyroid cancer cells].

Both c-myc and c-Ha-ras 1 oncogenes amplification and enhanced expression were revealed in some human mammary and thyroid carcinomas by the molecular genetic analysis. Amplification proves to be a second possible molecular mechanism of the ras family protooncogene activation besides a point mutation. The coexistence of c-myc and c-Ha-ras 1 in some human primary carcinomas suggests a multistep process of carcinogenesis.

Breast Neoplasms↗
PubMed1986

[Virus-specific proteins in cells transformed by the chicken sarcoma virus D6].

The structural proteins and the oncogene product of the avian sarcoma virus (ASV) D6 were analyzed by the radioimmunoprecipitation. ADV D6 was obtained from the chemically induced tumour. ASV D6 contains all the structural proteins found in RSV, but some of them (p19, gp 85) differ from those of RSV. The product of ASV D6 oncogene is pp65src. The protein kinase activity of this src protein is identical to that of wt pp60src. The nature of some other proteins, which can be phosphorylated in this reaction, is discussed.

Animals↗
PubMed1986

[Amplification of myc-specific sequences in human colonic cancer].

DNA samples obtained from tumors and adjacent mucosa of the large bowel of a patient with large bowel multiple neoplasia were examined after Southern. The procedure established amplification of v-myc oncogene-related DNA sequences in 1 out of 5 tumors tested. Restriction fragments of amplified myc-specific sequences and matching c-myc and N-myc loci of the human genome differed in size.

Adenocarcinoma↗
PubMed1985

[Use of nucleic acid preparative electrophoresis in molecular oncological research].

Application of preparative electrophoresis in agarose gel for isolation of chromosomal and extrachromosomal genetic elements is described. The above-mentioned method is used for fractionation of chromosomal DNA according to the molecular weight; for isolation of the plasmid containing the insertion of the viral oncogene myc and for separation of the viral oncogene myc insertion from the vector (a linear form of plasmid pBR 322). The method can be successfully applied in molecular biology, microbiology and medicine.

Chromosomes, Human↗