Biomedical subjects

M Nishigaki

Publications and source records attributed to M Nishigaki.

At least 19 recordsLinked to original sources

PubMed2001

2-Arachidonoylglycerol and anandamide oppositely modulate norepinephrine release from the rat heart sympathetic nerves.

Anandamide (10(-7) and 10(-6) M) as well as a synthetic cannabinoid HU210 (10(-8) to 10(-6) M) suppressed the norepinephrine release evoked by perivascular nerve stimulation (PNS) of the rat heart Langendorff's preparation. The effects of HU210 and the lower dose of anandamide were completely blocked by the cannabinoid CB1-receptor antagonist AM251, while that of anandamide at 10(-6) M was partly mediated by arachidonate-derived metabolites. 2-Arachidonoylglycerol (2-AG), at 10(-6) M in the presence of DFP and indomethacin, increased PNS-evoked norepinephrine release, which was completely blocked by AM251. The present results suggest that the two endocannabinoids may oppositely participate in the CB1-receptor-mediated modulation of sympathetic norepinephrine release.

Animals↗

PubMed2000

Different turnover rate of hepatitis C virus clearance by different treatment regimen using interferon-beta.

BACKGROUND/AIM: Since patients with high viral load and HCV subtype 1b are known to respond poorly to interferon (IFN) therapy, the viral dynamics of HCV RNA after initiation of interferon therapy were examined in the present study with respect to two different administration regimens, once vs. twice a day. METHODS: Twenty-two patients with chronic hepatitis C confirmed by liver biopsy and with >1 Meq/ml of HCV RNA and HCV subtype 1b were randomly assigned to two different IFN administration regimens (6 million units of IFN once a day or 3 million units of IFN twice a day), and the serum HCV RNA level was serially measured. RESULTS: Graphs of HCV RNA levels vs. treatment time showed an initial rapid fall, followed by a slower clearance phase. Fitting the data to a model for HCV decay proposed by Neumann et al. showed that the treatment efficacy was significantly higher with twice daily administration. Negativity for HCV RNA measured by Amplicor assay in the twice-a-day administration group was 18%, 73% and >89% at 1, 2 and 3 weeks, respectively, in contrast to 0%, 0%, and 18%, respectively, with once-a-day administration. However, a significant reduction of platelet count and albumin level, a marked increase in serum aspartate aminotransferase/alanine aminotransferase, and a high incidence of renal toxicity (proteinuria) were found in patients receiving IFN twice a day in comparison with those receiving it once a day. CONCLUSION: The twice-a-day administration of IFN accelerated the clearance of HCV RNA from serum, leading to a more efficient virological response for patients with chronic hepatitis C, but with a high rate of renal toxicity.

Adult↗

PubMed1998

[Adjuvant chemotherapy with UFT or UFT with OK-432 to patients with gastric and colorectal cancer. Kanto Adjuvant Study Group].

In Japan, long-term oral therapy with tegafur in combination with immunopotentiators is commonly used as adjuvant therapy after curative resection of gastric or colorectal can for gastric and colorectal cancer. When the outcome was analyzed in terms of the relative performance (R.P.) and the individual dose intensity (I.D.I.) of OK-432, gastric cancer patients with a R.P. of 0.5 or higher tended to have a better survival curve. There were no marked differences in lymphocytes subsets, except that the Leu 7 level at 3 months after gastric cancer resection was significantly higher (p < 0.05) in group B than in group A. Thus, no inhibition of the anticancer effect of UFT was noted during long term combination therapy with UFT and an immunopotentiator as postoperative adjuvant therapy for patients who underwent curative resection of gastric or colorectal cancer. The results suggest that UFT combined with long-term OK-432 maintenance therapy may contribute to improve survival rates in gastric cancer patients.

Adjuvants, Immunologic↗

PubMed1995

Danazol decreases transcription of estrogen receptor gene in human monocytes.

1. Administration of danazol for over one month reduced the levels of estrogen receptor (ER) and its mRNA to approximately 50 and 20%, respectively in monocytes. 2. Danazol did not alter the degradation rate of ER mRNA in monocytes. 3. Danazol decreased the transcription rate of ER gene to approximately 50% in monocytes in a run-on assay. 4. Danazol may release estrogen predominance via the reduction of transcription for ER gene, which leads to the reduction of ER mRNA and ER expressions in monocytes.

Adult↗

PubMed1995

Expression of progesterone receptor form A and B mRNAs in gynecologic malignant tumors.

This study was designed to examine the biological implication of progesterone receptor (PR) forms A and B mRNA expressions in gynecologic cancers. The ratio of PR form A to form B in mRNA expression was approximately 1:1 in all endometria studied. The predominant expressions of form B transcript occurred in 6 out of 7 cases of advanced stages (stages III and IV) in ovarian cancers, in 5 out of 9 cases of cervical cancers, and in 5 out of 11 cases of endometrial cancers. In conclusions, the dominancy of PR form B mRNA expression might be associated with the expression of a malignant phenotype in gynecologic cancers, and advanced clinical stage in ovarian cancers, suggesting a biological marker of malignant phenotype in these three types of cancer cell.

Adult↗

PubMed1995

Effects of danazol and medroxyprogesterone acetate on estrogen-(estradiol and estriol) specific binding sites in rabbit uterus.

In rabbit uterus, the presence of separate specific binding sites for not only estradiol but also estriol has been proposed. These sites may be correlated with an antiestradiol effect. Therefore, this study was designed to investigate the effect of antiestrogenic agents such as danazol and medroxyprogesterone acetate (MPA), especially on the estriol binding sites. Danazol and MPA in combination with estradiol were administered subcutaneously to immature female rabbits daily for 10 days, and resulted in a significant (p < 0.05) decrease in uterine weight and estradiol binding sites in the uterus. Treatment with MPA significantly (p < 0.05) decreased the level of estriol binding sites, but treatment with danazol resulted in this to a minimal extent in the uterus primed by estradiol. MPA did not bind to estradiol and estriol binding sites, while danazol at a high concentration bound to estriol binding sites with some affinity, but not to estradiol binding sites in the uterine cytosol of estrogen-primed rabbits. These results suggest that within the antiproliferative effect of danazol and MPA (an antiestrogenic action on estrogen-stimulated uterine growth) there are likely to be specific differences between some of the possible mechanisms of danazol and MPA in their action at the estriol binding site.

Animals↗

PubMed1995

Biological implications of estrogen and androgen effects on androgen receptor and its mRNA levels in human uterine endometrium.

It has been shown that some effects of testosterone are different from those of its 5 alpha-reduced metabolite, dihydrotestosterone. Briefly, activities of testosterone might be related to cellular differentiation, whereas dihydrotestosterone acts on cellular proliferation. The number of testosterone binding sites in the uterine endometrium was increased by estradiol dipropionate, and this increase was down-regulated by testosterone cypionate. Dihydrotestosterone-specific binding sites in the endometrium were not modulated by estradiol dipropionate and testosterone cypionate. The dissociation constants of the binding sites for testosterone and dihydrotestosterone were not altered by these steroids. Estradiol dipropionate with or without testosterone cypionate induced androgen receptor mRNA expression in the endometrium. In conclusion, testosterone might predominantly affect cellular differentiation in the endometrium.

Adult↗

PubMed1994

The effect of estrogen and androgen on androgen receptors and mRNA levels in uterine leiomyoma, myometrium and endometrium of human subjects.

This study was designed to show the effect of estrogen and androgen on the level of testosterone and dihydrotestosterone specific binding sites (TBS and DHTBS, respectively) and to clarify the implication of androgen receptor mRNA expression to TBS and DHTBS in human uterine tissues. Estrogen mainly induces the increase of TBS and androgen receptor mRNA in uterine endometrium and leiomyoma. TBS increased by estrogen are downregulated when testosterone is given along with estrogen, while androgen receptor mRNA increased by estrogen was not significantly altered by testosterone with estrogen in endometrium and leiomyoma. These results suggest that the androgen receptor mRNA determined might encode TBS and that testosterone may stimulate the metabolic rate of TBS, or inhibit the translation rate of androgen receptor mRNA to TBS. Furthermore, the biological character of leiomyoma is considered to be an endometrial type.

Adult↗

PubMed1994

Expression of aberrant estrogen receptor mRNA in endometrial cancers in comparison with normal endometria.

In endometrial cancers, some overexpression of estrogen receptor (ER) mRNA occurred in comparison with the ER mRNA level in normal endometria. DNA binding domains (DBDs) of ER mRNA were detected in 100% (13/13) of the endometrial cancers, and a mutated ER-DBD mRNA was found in 3 of the 13 by S1 nuclease protection analysis. It is suggested that estrogen might lead to disorder in the promotion of estrogen-inducible proteins in these 3 endometrial cancers, which seem to have a point-mutated DBD of the ER and a functional steroid-binding domain, resulting in the dedifferentiation of the original cells, and that the development and growth of cancer cells might, in part, be driven by estrogen.

Adult↗

PubMed1994

Tissue differences in the expression of mRNAs of Ha-ras, c-myc, fos and jun in human uterine endometrium, myometrium and leiomyoma under the influence of estrogen/progesterone.

Ha-ras expression level in uterine endometrium (EM) in the proliferative phase (PP) was significantly higher than that in the secretory phase (SP). c-myc expressions were detected in EM, uterine myometrium (MM) and uterine leiomyoma (LM) without any cyclic change; fos expressions in LM, MM, and EM were detectable in PP, but not in SP. jun expression level in LM was significantly higher than that in MM and EM in PP, but did not alter during the menstrual cycle. Estrogen elevated the levels of Ha-ras and fos mRNAs in the three tissues, jun mRNA in MM and EM, and c-myc mRNA in LM and MM. These results suggest that there is a tissue difference in the expression of Ha-ras, c-myc, fos and jun among EM, MM and LM, under the influence of estrogen/progesterone.

Adult↗

PubMed1994

[Inhaled nitric oxide after Fontan type operation].

The indication of Fontan type operation has been extending, but some cases on the boundary of the indication resulted in low cardiac output syndrome (LOS) postoperatively. Recently the inhalation of nitric oxide (NO) has been revealed to produce selective pulmonary vasodilatation, and it has come to be applied in the clinical setting. We experienced a case of 6-year-old boy with complex cardiac anomaly in whom the inhalation of nitric oxide was remarkably effective for the LOS caused by increased pulmonary vascular resistance after Fontan type operation. In the case various conventional treatments failed to improve his LOS during the weaning from a respirator on the second postoperative day. After the initiation of the inhalation of nitric oxide at a concentration of 6ppm, a rapid decreasing of pulmonary artery pressure concomitant with an improvement of hemodynamics were obtained. We concluded that the inhalation of nitric oxide is an effective strategy for the increased pulmonary resistance after Fontan type operation.

Administration, Inhalation↗

PubMed1992

[Sero-diagnosis for human parvovirus B19 infection by IgM and IgG antibody capture method of enzyme-linked immunosorbent assay--study on an epidemic case of erythema infectiosum].

The IgM and IgG antibody capture methods of the enzyme-linked immunosorbent assay (ELISA) for human parvovirus B19 were performed using Horseradish peroxidase (HRPO)-labeled anti B19 monoclonal antibody. Serially obtained serum samples from one erythema infectiosum (E.I.) patient were examined at once by this methods. The dOD values of the IgM and IgG antibodies decreased on the typical curves according to the course of recovery. In the epidemic case of E.I. among students of one nurse school, 1) The first patients was estimated by comparing the change of dOD values of sera obtained at end of the epidemic and 1.5 months later. 2) In the pre-existing antibody positive persons, the dOD values of IgG antibody did not changed during the epidemic. 3) After the E.I. epidemic, and approximately 30% of the students were remained uninfected.

Antibodies, Viral↗

PubMed1992

A case of malignant lymphoma accompanied by Klinefelter's syndrome.

A 66-year-old Japanese male with diffuse non-Hodgkin's lymphoma, of the pleomorphic type, complicated with Klinefelter's syndrome is reported. His phisique was characterized by a long arm span, disproportionately longer lower body dimensions and a small sized penis. He had no children. Chromosomal study revealed 47, XXY and hormonal quantification showed hypergonadtropic hypogonadism. Although chemotherapy was administered, his disease took a progressive course and he died. A discussion of chromosomal alteration and oncogenesis and review of the literature are included.

Aged↗

PubMed1985