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Biomedical subjects

C Deb

Publications and source records attributed to C Deb.

At least 19 recordsLinked to original sources
PubMed2001

Decrease in platelet serotonin level in uterine cervix cancer patients.

Platelet serotonin (5-HT) concentration was measured by HPLC with electrochemical detection in 46 women suffering from cancer of the uterine cervix and 16 matched controls. About 53% reduction (p < 0.05) was recorded in platelet 5-HT level in cancer patients against a control value of 1.29 +/- 0.16 (mean +/- S.E.) nmol per 10(9) platelets. Depletion of intraplatelet 5-HT was positively correlated with clinical stage of the disease although a modest rise (p > 0.05) in platelet 5-HT was observed in patients at stage I. Serotonin release from platelets following activation with thrombin was considerably increased in cancer patients (38.2% compared to 17.4% in controls). The results demonstrate progressive depletion of intraplatelet 5-HT in cervical cancer patients. In addition, their platelets release more 5-HT than the controls upon activation by thrombin.

Biomarkers, Tumor↗
PubMed2000

A soxA gene, encoding a diheme cytochrome c, and a sox locus, essential for sulfur oxidation in a new sulfur lithotrophic bacterium.

A mobilizable suicide vector, pSUP5011, was used to introduce Tn5-mob in a new facultative sulfur lithotrophic bacterium, KCT001, to generate mutants defective in sulfur oxidation (Sox(-)). The Sox(-) mutants were unable to oxidize thiosulfate while grown mixotrophically in the presence of thiosulfate and succinate. The mutants were also impaired in oxidizing other reduced sulfur compounds and elemental sulfur as evident from the study of substrate oxidation by the whole cells. Sulfite oxidase activity was significantly diminished in the cell extracts of all the mutants. A soxA gene was identified from the transposon-adjacent genomic DNA of a Sox(-) mutant strain. The sequence analysis revealed that the soxA open reading frame (ORF) is preceded by a potential ribosome binding site and promoter region with -10- and -35-like sequences. The deduced nucleotide sequence of the soxA gene was predicted to code for a protein of 286 amino acids. It had a signal peptide of 26 N-terminal amino acids. The amino acid sequence showed similarity with a putative gene product of Aquifex aeolicus, soluble cytochrome c(551) of Chlorobium limicola, and the available partial SoxA sequence of Paracoccus denitrificans. The soxA-encoded product seems to be a diheme cytochrome c for KCT001 and A. aeolicus, but the amino acid sequence of C. limicola cytochrome c(551) revealed a single heme-binding region. Another transposon insertion mutation was mapped within the soxA ORF. Four other independent transposon insertion mutations were mapped in the 4.4-kb soxA contiguous genomic DNA region. The results thus suggest that a sox locus of KCT001, essential for sulfur oxidation, was affected by all these six independent insertion mutations.

Amino Acid Sequence↗
PubMed1997

Cloning and characterization of a high-copy-number novel insertion sequence from chemolithotrophic Thiobacillus ferrooxidans.

Two distinct families of repetitive DNA elements (1.4 and 1.2 kb) were identified from S1 nuclease-treated genomic DNA of four strains of Thiobacillus ferrooxidans. The 1.4-kb fragment hybridized with IST2, an insertion sequence of T. ferrooxidans. The 1.2-kb fragment was cloned and sequenced. The sequence (IST445), 1219 bp in length, with features characteristic of an insertion element, has a terminal inverted repeat of 8 bp, which can be further extended to 23 or 48 bp with 9 and 26 mismatches, respectively. It displays 54.4% identity in 967 nucleotides of overlap with ISAE1 of Alcaligenes eutrophus. The IST445 contains three open reading frames which have codon usage almost similar to 56 different coding genes of T. ferrooxidans. In Southern blots of restricted genomic DNAs probed with IST445, each of the several strains of T. ferrooxidans gives a distinctive fingerprint. IST445 is present in the range of 10-20 copies per genome in the four strains studied.

Amino Acid Sequence↗
PubMed1994

Mitomycin C induced inhibition of adrenal steroidogenesis in female rats.

Mitomycin C (MC), an antibiotic which depresses DNA synthesis causes suppression of enzyme delta 5 3 beta-hydroxysteroid dehydrogenase (delta 5 3 beta OHD) and glucose-6 phosphate dehydrogenase (G-6 PD) in the rat adrenal tissue. The treatment resulted in a fall in DNA content together with an accumulation of cholesterol and ascorbic acid in the gland. The results suggest a diminution in adrenal steroid biogenesis similar to gonadal inhibition previously reported.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1992

Quinalphos-induced suppression of spermatogenesis, plasma gonadotrophins, testicular testosterone production, and secretion in adult rats.

Quinalphos (O,O-diethyl-O-[quinoxalinyl-(2)-thionophosphate]) is a well-known organophosphorus insecticide used extensively in agriculture that adversely interferes with the activity of testicular steroidogenic enzymes in rats. To investigate its effects on spermatogenesis, the other function of testes, quantitative evaluation of different varieties of germ cells at stage VII of the seminiferous epithelium cycle, namely, type A spermatogonia (ASg), preleptotene spermatocytes (pLSc), midpachytene spermatcytes (mPSc), and step 7 spermatids (7Sd), along with the radioimmunoassay of plasma FSH, LH, testosterone, and testicular testosterone, were performed in Wistar rats following treatment with quinalphos (250 micrograms/kg, ip) for approximately one (13 days) and two cycles (26 days) of the seminiferous epithilium. Massive degeneration of all varieties of germ cells at stage VII, remarkable reduction in the sperm count, and significant reductions in plasma concentrations of FSH and testosterone, along with testicular testosterone, were observed after quinalphos treatment. Significant reduction in the plasma concentration of LH was observed only after treatment for two cycles. Administration of human chorionic gonadotrophin for 26 days in rats injected with quinalphos partially prevented the degeneration of germ cells and increased testosterone production. It is suggested that quinalphos may have a suppressive influence on gonadotrophin release but its direct detrimental action at the level of the testes may also be responsible for the observed changes in spermatogenesis and in testicular testosterone production in rats.

Animals↗
PubMed1991

Suppressive effect of quinalphos on the activity of accessory sex glands and plasma concentrations of gonadotrophins and testosterone in rats.

Biochemical estimation of prostatic acid phosphatase and fructose content in accessory sex glands, along with radioimmunoassay of plasma gonadotrophins (FSH and LH) and testosterone were performed in Wistar rats following treatment with quinalphos, an organophosphorus insecticide, for 13 and 26 days. Prostatic acid phosphatase activity and fructose content of the accessory sex glands, and plasma levels of testosterone and FSH were significantly lower in all rats treated with quinalphos. However, the degree of inhibition was more extensive in the 26 day-treatment group who, in addition also exhibited a significant reduction in relative weights of the testes and accessory sex organs, and plasma levels of LH. All these adverse effects of quinalphos were prevented when exogenous HCG was administered in concomitant with the insecticide for 26 days. These results suggest that quinalphos may exert a suppressive effect on the functional activity of accessory sex glands by decreasing testicular testosterone production following inhibition of pituitary gonadotrophins release.

Animals↗
PubMed1988

Effect of aldrin on spermatogenesis, plasma gonadotrophins and testosterone, and testicular testosterone in the rat.

Quantitative evaluation of the different varieties of germ cells at stage VII of the seminiferous epithelium cycle, namely type-A spermatogonia (ASg), preleptotene spermatocytes (pLSc), mid-pachytene spermatocytes (mPSc) and step 7 spermatids (7Sd), along with radioimmunoassay of plasma gonadotrophins (FSH and LH), testosterone and testicular testosterone were performed in Wistar rats following treatment with aldrin (polycyclic chlorinated hydrocarbon insecticide) for approximately one (13 days) or two cycles (26 days) of the seminiferous epithelium. Extensive degeneration of all varieties of germ cells at stage VII, reduction in the sperm count and significant reductions in plasma concentrations of LH and testosterone were observed following aldrin treatment. The reduction in plasma concentrations of FSH was statistically significant only after treatment for two cycles. The inhibitory effect of aldrin on plasma gonadotrophins, testosterone levels, testicular testosterone content and numbers of 7Sd and ASg was maximum after treatment for two cycles. Administration of human chorionic gonadotrophin along with aldrin treatment for two cycles partially prevented the degeneration of germ cells and enhanced testosterone production. The results indicate that aldrin may have a direct inhibitory influence on gonadotrophin release, but the possibility of a direct action of the insecticide at the level of the testes is also discussed.

Aldrin↗
PubMed1983

Possible role of pituitary in Mitomycin C induced inhibition of testicular steroidogenesis.

To find out the role of pituitary in Mitomycin C (MC) induced reduction of testicular steroidogenesis, MC was administered along with HCG and the testicular steroidogenic activity was assessed on the basis of different parameters which are directly and indirectly related to the rate of testicular steroid biogenesis. The results indicate that MC induced reduction in testicular steroidogenesis is not only due to its direct effect but suppression of pituitary gonadotrophin secretion may be one of the responsible factor.

3-Hydroxysteroid Dehydrogenases↗
PubMed1980

Action of mitomycin C on testicular steroidogenesis in immature rats.

Treatment with mitomycin C resulted in a decrease in the testicular delta 5-3 beta-hydroxysteroid dehydrogenase level along with a fall of Leydig cell nuclear area. Following the same treatment the significant fall of sex accessory organ weights and testicular accumulation of ascorbic acid and cholesterol were noted. On the basis of above evidence it is suggested that mitomycin C probably suppressed testicular steroidogenesis.

3-Hydroxysteroid Dehydrogenases↗
PubMed1979

Enhanced steroidogenesis in hen ovary after malonate administration.

The activities of glucose-6-phosphate dehydrogenase, delta 5-3 beta-hydroxysteroid dehydrogenase and succinic dehydrogenase have been studied histochemically in the ovary of normal and malonate treated hens. Following malonate treatment, glucose-6-phosphate dehydrogenase and delta 5-3 beta-hydroxysteroid dehydrogenase showed increased activities while succinic dehydrogenase activity was diminished significantly. The significance of the above changes has been discussed. The ascorbic acid and cholesterol contents of the ovary were determined to get additional information about steroidogenesis in the gland under such treatment.

3-Hydroxysteroid Dehydrogenases↗