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Biomedical subjects

A Ohara

Publications and source records attributed to A Ohara.

At least 109 records · Page 6Linked to original sources
PubMed1988

[Primary carcinoma of the fallopian tube: its clinical aspects and problems in the postoperative staging system].

Clinical features of primary carcinoma of the fallopian tube were studied in 13 patients treated in Osaka National Hospital between 1961 and 1987. The relationship between clinical staging and prognosis in each patient is discussed. The incidence of this disease among all cases of malignant tumor in the gynecological department during the same 27-year period was 0.18%. The mean age of the patients was 50.7 years. Twelve patients (92%) were within the age range from 41 to 59 years, the most common age of onset. Six patients (46%) were nulligravida and 9 (69%) were nulliparous, suggesting infertility as a possible important risk factor for the disease. None of the six who underwent cervical cytodiagnosis showed tumor cells. Three were positive for cytodiagnosis by aspiration biopsy. The concomitant use of many drugs, including CDDP given postoperatively to 2 patients with advanced disease, was markedly effective. The radiotherapy carried out in 4 patients was ineffective. When the patients were staged according to the classifications of Dodson et al. and Schiller et al., there was no difference between these classifications in advanced cases. However, Dodson et al.'s classification was considered unsuitable for patients with early-stage cancerous lesions localized in the fallopian tube, while that of Schiller et al. was considered to be superior in evaluating prognosis.

Adult↗
PubMed1987

Mutagens formed from butylated hydroxyanisole treated with nitrite under acidic conditions.

The reaction products from butylated hydroxyanisole treated with nitrite under acidic conditions were investigated for mutagenic activity in Salmonella typhimurium his reversion assay and for DNA-damaging activity using H17 Rec+ (wild) and M45 Rec- (recombinationless) of Bacillus subtilis. The chloroform extract of the reaction mixture showed 9 spots on thin-layer chromatography (TLC). Compounds from 2 spots on the TLC had high mutagenic activity in TA100 without S9 mix, with DNA-damaging activity. The 2 mutagens were then crystallized from the reaction mixture and identified to be 2-tert.-butyl-p-quinone (t-BQ) and the dimer of t-BQ; 3,3'-di-tert.-butyl-biphenyldiquinone-(2,5,2',5') (BBDQ), from their instrumental analysis. The mutagenic activities of t-BQ and BBDQ were determined by Ames test, and the induced mutation frequencies were about 1.9 X 10(-4) (t-BQ) and 8.3 X 10(-5) (BBDQ).

Animals↗
PubMed1987

Functional differentiation in steroidogenesis of two types of luteal cells isolated from mature human corpora lutea of menstrual cycle.

Enriched small and large cell fractions were prepared from mature corpora lutea from 15 women in the midluteal phase by enzymatic dissociation, followed by Percoll gradient centrifugation. The steroidogenic function of each cell type was assessed by measuring the gonadal steroids released into the incubation medium. The large cell fraction was estimated to be 97% pure, with minimal contamination by small cells, whereas the small cell fraction was approximately 68% pure, being contaminated with 10% large cells and 22% nonsteroidogenic cells. In the unstimulated state, large cells were approximately 2-fold more potent in progesterone formation and aromatase activity, but only half as potent in androstenedione and testosterone formation as an equal number of small cells. When stimulated with hCG, the small cells responded with significant increases in progesterone, androstenedione, and testosterone release, but the large cells did not. Both cell types secreted estrone and 17 beta-estradiol in the presence of androgen substrate, but the addition of FSH significantly stimulated aromatization only in large cells. Thus, small and large human luteal cells have steroidogenic properties similar to those exhibited by follicular thecal and granulosa cells, respectively.

Androstenedione↗
PubMed1987

Effect of recombinant human granulocyte colony-stimulating factor on hemopoietic cells in serum-free culture.

The effect of recombinant human erythropoietin (Ep) and granulocyte colony-stimulating factor (G-CSF) on colony formation by human hemopoietic progenitors was examined in a methylcellulose culture system. In the serum-containing culture system, granulocyte-macrophage (GM) colonies and erythroid bursts were formed by non-phagocytic mononuclear cells only in the presence of Ep. To exclude the effect of the serum, which may have hemopoietic factors, we replaced the serum with bovine serum albumin, transferrin, and lipids. In serum-free culture, recombinant Ep supported erythroid colony formation, but not erythroid burst formation. While G-CSF could support the proliferation of macrophages (30%) as well as neutrophils in the presence of fetal calf serum (FCS), it supported mainly neutrophils (97%) in serum-free culture. In this culture system, G-CSF could not induce burst formation in the presence of Ep. By using a serum-free culture system, we found that human G-CSF is a lineage-specific hemopoietic factor which acts on granulocyte-committed progenitor cells and not on early erythroid progenitor cells.

Blood Proteins↗
PubMed1985

The presence of essential histidine residues in manganese(III)-containing acid phosphatase from sweet potato.

Chemical modification studies of manganese(III)-containing acid phosphatase [EC 3.1.3.2] were carried out to investigate the contributions of specific amino-acid side-chains to the catalytic activity. Incubation of the enzyme with N-ethylmaleimide at pH 7.0 caused a significant loss of the enzyme activity. The inactivation followed pseudo-first-order kinetics. Double log plots of pseudo-first-order rate constant vs. concentration gave a straight line with a slope of 1.02, suggesting that the reaction of one molecule of reagent per active site is associated with activity loss. The enzyme was protected from inactivation by the presence of molybdate or phosphate ions. Amino acid analyses of the N-ethylmaleimide-modified enzyme showed that the 96%-inactivated enzyme had lost about one histidine and one-half lysine residue per enzyme subunit without any significant decrease in other amino acids, and also demonstrated that loss of catalytic activity occurred in parallel with the loss of histidine residue rather than that of lysine residue. Molybdate ions also protected the enzyme against modification of the histidine residue. The enzyme was inactivated by photooxidation mediated by methylene blue according to pseudo-first-order kinetics. The pH profile of the inactivation rates of the enzyme showed that an amino acid residue having a pKa value of approximately 7.2 was involved in the inactivation. These studies indicate that at least one histidine residue per enzyme subunit participates in the catalytic function of Mn(III)-acid phosphatase.

Acid Phosphatase↗