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Biomedical subjects

R Nishimura

Publications and source records attributed to R Nishimura.

At least 307 records · Page 17Linked to original sources
PubMed1981

Studies on the cytotoxicity, mutagenicity and chromosomal aberration-inducing activity of aclacinomycin A in cultured mammalian cells.

The cytotoxicity mutagenicity and chromosomal aberration-inducing activity of aclacinomycin A were studied using cultured mammalian cells. Aclacinomycin A was found to be a potent inhibitor of RNA synthesis in HeLa S3 cells. The survival curve in the presence of aclacinomycin A exhibited a concentration- and time-dependent cytocidal effect, and showed a sigmoidal shoulder. A cytofluorometric study suggested that aclacinomycin A caused a temporary blockage of cell cycle progression. In mutation assay using V79 cells, aclacinomycin A was shown to induce 8-azaguanine-resistant mutation, being several times more mutagenic than adriamycin. The induction of chromosomal aberrations by aclacinomycin A was also demonstrated. When cells from various sources were treated with aclacinomycin A, they were affected at a similar concentration with the exception of human normal fibroblasts, which were a little less sensitive than the others.

Aclarubicin↗
PubMed1980

Electroencephalographic findings in Gaucher disease.

The electroencephalographs (EEGs) of 26 patients with Gaucher disease were reviewed. Eleven cases with abnormal EEGs or neurologic complications are reported, and the findings of the abnormal recordings are discussed.

Adolescent↗
PubMed1980

Partial characterization of 5 alpha-reductase in the human epididymis.

The properties of 5 alpha-reductase in the human epididymis were studied. When testosterone-4-14C was incubated with the whole homogenate of human epididymis in the presence of NADPH, the identifed metabolites of the substrate were 5 alpha-dihydrotestosterone and 5 alpha-androstane-3 alpha, 17 beta-diol. 5 alpha-reductase activity was mainly localized in the microsomal and nuclear fractions. The Km values of the 5 alpha-reductase for testosterone in the microsomal and nuclear fractions were 1.07 x 10(-8) M and 0.83 x 10(-8) M, respectively. The optimum pH of the 5 alpha-reductase activity was 5.7 for the microsomal fraction and 5.5 for the nuclear fraction. The optimum temperature was about 48 degrees C for 5 alpha-reductase in both the microsomal and nuclear fractions. The most preferable cofactor for the microsomal 5 alpha-reductase was NADPH and the Km value of the enzyme for NADPH was 2.1 x 10(-6) M. These results confirm the presence of 5 alpha-reductase in the human epididymis and suggest that the enzyme has considerable affinity for testosterone and that the properties of 5 alpha-reductase in the microsomal fraction are similar to those in the nuclear fraction.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1980

Negative feedback effects of chlormadinone acetate and ethynylestradiol on gonadotropin secretion in patients with prostatic cancer and male rats.

Serum LH and FSH levels were determined before and after LH-RH injection (100 micrograms, i.m.) in patients with prostatic cancer who were chronically treated with either chlormadinone acetate (CMA, 100 mg/day) or ethynylestradiol (EE, 1 mg/day). In patients treated with EE, the levels of serum LH and FSH before and after injection of LH-RH were significantly lower than those in controls. On the other hand in patients treated with CMA, the basal levels of serum gonadotropins did not differ from those in controls, and the increase in gonadotropin after LH-RH injection was comparable to that in controls. To examine the effects of these steroids on the hypothalamo-hypophysial axis in the regulation of gonadotropin secretion, CMA or EE was implanted in castrated male rats. CMA, EE or cholesterol (control) was implanted in the hypothalamic median eminence-arcuate nucleus region through a stainless doublecannula. EE implantation resulted in a 75% decrease in serum LH (p < 0.001) and a 38% decrease in serum FSH (p < 0.05) from the control levels on day 5 of implantation. On the other hand, CMA implantation induced a 33% decrease in serum LH (p < 0.05) from the control level on day 3 of implantation, but no significant change in serum FSH levels. The injection of 2 micrograms/kg of LH-RH on day 7 of implantation induced significant lowering of LH and FSH levels. There was no significant difference between serum levels of the hormones 20 min after LH-RH injection for these two groups and those for the control group. These studies suggest that EE has a potent negative feedback effect on both LH and FSH secretion, and that CMA has a mild negative feedback effect on LH secretion.

Aged↗
PubMed1979

The clinical evaluation of the simultaneous measurements of human chorionic gonadotropin (hCG) and its alpha-subunit in sera of patients with trophoblastic diseases.

The concentrations of human chorionic gonadotropin (hCG) and its free immunoreactive alpha-subunit (hCG-alpha) in the sera of patients with trophoblastic diseases were measured by hCG and hCG-alpha radioimmunoassay (RIA), respectively. In the sera of 12 women with hydatidiform mole large amounts of hCG and considerably high level of hCG-alpha were detected in all cases. After the evacuation of mole the serum level of these glycoproteins decreased, the leve of hCG-alpha declined more rapidly than hcg. in the sera of patients with destructive mole the concentration of hCG-alpha was usually lower than that of hCG. After hysterectomy and chemotherapy the levels of hCG-alpha declined practically paralleling that of hCG. However, when hCG had decreased to undetectable level, hCG-alpha could no longer be detected in all cases. Although in the serum of patient with choriocarcinoma involving the uterus and lungs the concentration of hCG-alpha was almost as high as that of hCG, the secretory pattern of hCG and hCG-alpha might not be closely related. The changes in the serum level of free hCG-alpha as well as that of hCG parelled the clinical course of the patients examined in this study. The present results suggest that measurements of the serum free hCG-alpha may be a useful parameter to follow the clinical course and to evaluate the efficacy of treatments of trophoblastic diseases.

Adult↗
PubMed1979

Effect of hyperthermia on DNA single-strand breaks induced by bleomycin in Hela cells.

The effect of hyperthermia (43 approximately 45 degrees) on DNA single-strand breaks induced by bleomycin was examined in HeLa cells by the alkaline sucrose gradient sedimentation analysis. When HeLa cells were exposed to a temperature of 43 degrees approximately 45 degrees for 1 hr, only a small number of DNA single-strand breaks than bleomycin treatment at 37 degrees. The DNA strand breaks induced by bleomycin were almost completely repaired by post-treatment incubation of the cells in the control medium at 37 degrees. On the contrary, the repairing capacity of the cells was markedly inhibited by post-treatment incubation at 43 degrees, and this inhibition of cell repair seemed irreversible because no repair was found after an additional incubation of the cells at 37 degrees for 1 hr. These results support the possibility that the mechanism of synergism between the effect of bleomycin and hyperthermia may be related to the inhibition of DNA repair.

Bleomycin↗
PubMed1978

Ampicillin therapy for pharyngeal gonorrhea.

Single-dose oral ampicillin trihydrate is ineffective for the treatment of pharyngeal gonorrhea. An evaluation was made of the efficacy of extended oral ampicillin therapy. The regimen consisted of a single oral 3.5-g dose of ampicillin trihydrate and 1.0 g of probenecid on the first day, followed by 500 mg of ampicillin tridhydrate four times a day for each of the succeeding two days, for a total ampicillin trihydrate dose of 7.5 g. One or two follow-up cultures taken within 35 days of completion of therapy were obtained in 77 of the 101 patients treated. Positive test-of-cure cultures were reported in three persons, two of whom may have been reinfected. The failure rate was calculated to range between 1.3% (1/77) to 3.9% (3/77). This compares favorably with current recommended modes of therapy.

Administration, Oral↗
PubMed1977

Congenital cystic dilation of the bile duct associated with Laurence-Moon-Biedl-Bardet syndrome.

We describe a 26-year-old man in whom the Laurence-Moon-Biedl-Bardet syndrome had been associated with congenital cystic dilations of both the intrahepatic and extrahepatic biliary tract. The fact of the simultaneous occurence of two rare diseases in a single patient suggests the congenital origin of cystic dilation of the biliary tract and the importance of examining for a possible association of anomalies in the alimentary tract with the Laurence-Moon-Biedl-Bardet syndrome.

Adult↗