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Biomedical subjects

M Iwao

Publications and source records attributed to M Iwao.

At least 37 records · Page 2Linked to original sources
PubMed1987

High-attenuation recent thrombus of the portal vein: CT demonstration and clinical significance.

Attenuation characteristics of portal vein thrombi on nonenhanced computed tomographic (CT) scans were assessed in 122 patients with proved portal vein thrombosis. Portal vein thrombi of high attenuation were found in four patients with hepatocellular carcinoma. From pathologic and radiologic studies, it was concluded that the high attenuation was caused by blood clots of recent onset formed at the tip of tumor thrombus. Differentiation from choledocholithiasis, hematobilia, and calcification of thrombi could be easily made by means of ultrasonography (US). Although plain CT is usually considered noncontributory in the diagnosis of venous thrombosis, it enabled the differentiation of recent thrombus in these four patients. Tumor thrombus in the major branches or main trunk of the portal vein is indicative of poor prognosis. When hepatic mass and high-attenuation portal vein thrombi are demonstrated with plain CT and substantiated by US, enhanced CT and angiography may be unnecessary for treatment of patients with advanced hepatocellular carcinoma.

Aged↗
PubMed1983

Microbial mutagenicity of 3- and 4-ring polycyclic aromatic sulfur heterocycles.

The stable isomers of 3- and 4-ring polycyclic aromatic sulfur heterocycles were tested for mutagenicity in the Ames standard plate incorporation test and a liquid pre-incubation modification of the Ames test. Of the 4 three-ring compounds tested, only naphtho[1,2-b]thiophene was mutagenic. Of the four-ring compounds, 7 of 13 were mutagenic in the standard Ames or pre-incubation Ames test. The highest activity for the 4-ring compounds was observed for phenanthrol[3,4-b]thiophene, a compound of approximately the same mutagenic potency in the Ames test as benzo[a]pyrene. The other active 4-ring compounds were of considerable less mutagenic potency than phenanthrol[3,4-b]thiophene. Mutagenicity for two of the 4-ring aromatic thiophenes could only be detected in the liquid pre-incubation Ames test. Salmonella typhimurium TA100 was the most sensitive strain to mutagenesis by these compounds, followed by TA98. All mutagenesis was indirect, requiring metabolic activation.

Animals↗
PubMed1982

Cervical ripening with dehydroepiandrosterone sulphate.

Dehydroepiandrosterone sulphate (DHEA-S) was given intravenously twice a week after 38 weeks gestation to ripen the uterine cervix in 20 nulliparae and 24 parous women who subsequently went into labour at term. The condition of the uterine cervix was assessed by Bishop scoring. The increase in the score in nulliparous women given DHEA-S was significantly greater than that in the control group, who were given placebo injections, on the 7th, 14th and 21st days. The increase in the parous women was significant only on the 7th day. In nulliparous women the dilatation, effacement and consistency improved significantly, while in the parous women the effect of DHEA-S was apparent only in the consistency. The duration of labour was significantly shortened by treatment with DHEA-S in nulliparae but this effect was not found in parous women. The interval between the first administration of DHEA-S and the onset of labour in nulliparae was significantly shorter than that in the control group. There were no serious side effects or complications. Our results suggest that DHEA-S may be used safely and effectively to ripen the uterine cervix and to trigger the onset of labour in late pregnancy.

Adolescent↗
PubMedDate not supplied

Inhibition of ovarian follicle growth by a chemical antiestrogen.

Effect of a chemical antiestrogen, cis-clomiphene, on FSH-induced ovarian follicle growth was studied morphometrically in hypophysectomized immature female rats. NIH-FSH-S12 alone or in combination with cis-clomiphene was injected to hypophysectomized rats and the ovarian weight, histological findings of the ovary, the number of growing and atretic follicles, the uptake of tritiated thymidine by the ovary and labelling indices of growing follicles were investigated with reference to their morphometric aspects. A chemical antiestrogen, cis-clomiphene, inhibited FSH-induced ovarian follicle growth. The results suggest that endogenous estrogen secretion plays a role in the ovarian response to FSH, and FSH-induced follicular growth is mediated by endogenous estrogen.

Animals↗
PubMedDate not supplied

A non-radioisotopic human natural killer cell assay using rhodamine-123 fluorescent dye as labelling probe.

A non-radioisotopic method for assessment of human natural killer (NK) cell activity in peripheral blood mononuclear cells (PBMC) was established by labelling K562 erythroleukemia target cells with a fluorescent dye, rhodamine-123 (Rh-123). The labelling and assay conditions were determined for minimizing spontaneous release (SR). In order to investigate whether NK activity assessed by measuring Rh-123 release agrees with the activity determined by a 51Cr release assay, the NK activity of PBMC was measured simultaneously by both assay methods. Statistical analysis demonstrates that NK activities determined by Rh-123 release correlate well with those measured by 51Cr release. The Rh-123 release assay under the conditions determined was found to be applicable to measurement of the enhanced NK activity resulting from pretreatment of effector leukocytes with interferon-alpha. It is concluded that the Rh-123 release assay with use of K-562 labelled target cells is practical for the assessment of human NK activity in laboratories where use of radioisotopes is not permitted or undesirable.

Chromium↗