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S Yoshimura

Publications and source records attributed to S Yoshimura.

At least 217 records · Page 12Linked to original sources
PubMed1988

Determination of nucleotide sequence of cDNA coding rat glutathione peroxidase and diminished expression of the mRNA in selenium deficient rat liver.

The cDNA for rat glutathione peroxidase mRNA was isolated from liver cDNA library in lambda gt11 by cross-hybridization using the mouse cDNA, and it's nucleotide sequence was determined. The selenocysteine which constitutes an active center of this enzyme was encoded by TGA, a nonsense codon in general, as was the cases with mouse and human glutathione peroxidase. Northern blot analysis elucidated that the mRNA for glutathione peroxidase was markedly diminished in selenium deficient rat liver as compared with that of normal rat livers. The result suggested that the de novo synthesis of the mRNA would be regulated by selenium.

Amino Acid Sequence↗
PubMed1988

Familial bulbo-spinal muscular atrophy associated with testicular atrophy and sensory neuropathy (Kennedy-Alter-Sung syndrome). Autopsy case report of two brothers.

Autopsy cases of two brothers with bulbo-spinal muscular atrophy associated with gynecomastia, testicular atrophy and sensory neuropathy are reported. The disease started with finger tremor, proximal muscle weakness and facial muscle twitching at the second and fourth decades, accompanied by bulbar signs and glove-stocking type sensory disturbance. Systemic neurogenic patterns and diminished sensory nerve action potential amplitudes were recorded by electrophysiological studies. A marked loss of myelinated fibers was noticed upon sural nerve biopsy. Gonadal hormone values were normal, except for elevated urinary estrogen. Postmortem examinations revealed a remarkable degeneration of the facial and hypoglossal nuclei, and the spinal cord motoneurons. The skeletal muscles and the tongue showed neurogenic muscular atrophy with fatty replacement. Testicular atrophy was prominent showing hyalinized seminiferous tubuli with nodular and diffuse Leydig cell hyperplasia, containing estrogen immunoreactive substance. These clinical and histological features seemed to be highly compatible with those of Kennedy-Alter-Sung type bulbo-spinal muscular atrophy. The involvement of sensory peripheral nerves, however, was a distinct feature of this family.

Aged↗
PubMed1988

Shift of atrial reentrant tachycardia with transient entrainment to an uncommon and a common type of atrial flutter.

Atrial reentrant tachycardia (ART) which demonstrated transient entrainment shifted to an uncommon type of atrial flutter (AF) with premature atrial stimulation, and then returned to ART spontaneously. Subsequently, this ART shifted to a common type of AF by rapid atrial pacing, which was further transformed into an uncommon type of AF and finally terminated by rapid atrial pacing. The mechanism of AF in clinical cases is still controversial, but in this case, AF, both uncommon and common types, is considered due to macro-reentry within the atria. To explain the shift of ART to AF and mutual transformation between common and uncommon type of AF, we made a schematic figure of reentry loop within the atria of ART and AF.

Aged↗
PubMed1988

Role of endogenous beta-adrenergic mechanism in the pathogenesis of spontaneous myocardial fibrosis in rats.

The role of endogenous beta-adrenergic activation in the pathogenesis of spontaneous myocardial fibrosis was investigated in male and female Sprague-Dawley (SD) rats. For the purpose of blocking endogenous beta-adrenergic activities, atenolol, a beta-adrenergic blocking a agent, was given at 20, 80 and 320 mg/kg/day mixed in the diet for 12 months. The transverse sections of the ventricles including the vulnerable region for spontaneous myocardial fibrosis was stained by Azan-Mallory method for collagen fibers and examined morphometrically, while being compared with the histological findings from standard hematoxylin-eosin procedure. The fibrosis was graded into 4 classes and compared between nontreated groups and treated groups of both sexes. Fibrous foci developed principally in the subendocardial myocardium. Atenolol failed to produce significant systemic toxic effects not only on weight gains and daily intakes of food but also on death rates. Atenolol did not prevent development of myocardial lesions in both sexes, whereas it significantly promoted fibrosis in the medium and high dose groups of male rats but not at any dose levels in female animals. It is suggested that endogenous beta-adrenergic activation plays no major role in the onset or development of spontaneous myocardial lesions, whereas the adrenergic system may probably control collagen synthesis in myocardial fibrosis.

Animals↗
PubMed1988

[Uptake of anticancer drugs by target organs and the usefulness of adjuvant chemotherapy].

Forty-one patients with advanced gastric cancer underwent gastrectomy, and the correlation between tissue uptake of the adjuvant drug and the prognosis were studied. The patients were preoperatively administered Tegafur and samples of tissue were obtained intraoperatively. 5-FU levels in the tumor and lymphnodes were measured by gas chromato-mass fragmentography (GCMF). The patients measured for 5-FU tissue uptake were given more than 60 g of tegafur as postoperative adjuvant chemotherapy, and divided into two groups; one in which the 5-FU uptake by tumor tissue and lymphnode was over 0.05 microgram/g and the other lower than 0.05 microgram/g. In both groups there were no significant differences in background factors. Each survival rate was calculated by the Kaplan-Meier method, and the generalized Wilcoxon method was used for statistical analysis. There was no statistically significant correlation between 5-FU uptake by the tumor and the prognosis, but the 5-year survival rate in the group with over 0.05 microgram/g uptake by lymphnodes was statistically significant (p = 0.018).

Adult↗
PubMed1987

Beta 2-adrenergic regulation of prostaglandin D2 receptor in rabbit platelets.

[3H]Prostaglandin D2 binding to rabbit platelets was increased by about 150% in the presence of beta-adrenoceptor agonist, isoproterenol. The isoproterenol-induced potentiation of the [3H]prostaglandin D2 binding gave a bell-shaped dose-response relationship (maximum response at 3 X 10(-8) M) in a stereospecific manner. Similar and moderate potentiation was obtained with terbutaline. On the other hand, beta-adrenoceptor antagonists such as alprenolol, propranolol and butoxamine (beta 2-specific) had no potentiating effect on [3H]prostaglandin D2 binding; rather, they abolished the isoproterenol-induced increase of [3H]prostaglandin D2 binding. The beta 1-specific antagonist, metoprolol, did not have any effect. Rabbit platelets were found to possess one [3H]prostaglandin D2 binding site (Kd = 6 X 10(-7) M, Bmax = 787 fmol/mg protein). In the presence of isoproterenol at 3 X 10(-8) M, Bmax was increased with unaltering Kd value. Isoproterenol did not increase [3H]prostaglandin E1, [3H]prostaglandin E2 and [3H]prostaglandin F2 alpha bindings to platelets. The potential effect of isoproterenol was mimicked by forskolin, theophylline, dibutyryl cyclic AMP, prostaglandin E1 and prostaglandin I2, but it was abolished by 2', 5'-dideoxyadenosine, an inhibitor of adenylate cyclase, indicating that elevated level of cyclic AMP may be available for the induction of the increase of [3H]prostaglandin D2 binding. Prostaglandin D2-induced cyclic AMP synthesis and antiaggregation activity were also augmented in the presence of isoproterenol. These results suggest a beta 2-adrenoceptor-mediated cyclic AMP-dependent mechanism for the regulation of prostaglandin D2 receptor binding in rabbit platelets.

Adenylyl Cyclase Inhibitors↗
PubMed1987

[Superovulation-induced transient hyperprolactinemia in human in vitro fertilization and embryo transfer].

To examine the effects of transient hyperprolactinemia on in vitro fertilization and embryo transfer, 61 cycles in 50 euprolactinemic ovulatory women with irreparable tubal diseases were stimulated with clomiphene (CC) alone or CC and human menopausal gonadotropin followed by human chorionic gonadotropin (hCG). Serum prolactin (PRL) increased after hCG administration with peak values of 45.4 +/- 4.2 ng/ml on the day of laparoscopic oocyte aspiration. The highest serum estradiol (E2) concentration was found on the day before PRL peak and serum progesterone (P) began to increase after hCG injection concomitant with the PRL rise. The group having 50 ng/ml or more of PRL (34 cycles) had significantly higher levels of E2 during preovulatory and early luteal phase compared to those of the group having less than 50 ng/ml of PRL (27 cycles) but there was no significant difference between the P levels in the two groups. In the higher PRL group 72 (62.1%) of 116 collected oocytes were fertilized and 6 (20.0%) conceived. In the lower PRL group 45 oocytes (58.4%) of 77 were fertilized and 3 (12.5%) became pregnant. These data suggest that elevated serum PRL concentrations may have no effect on fertilization of oocytes in vitro or embryonic development.

Adult↗
PubMed1986

Effects of decalcification on immunoperoxidase staining.

One of the limitations of immunoperoxidase methods applied in surgical pathology is the loss of immunoreactivity during fixation and processing. In this study, the effects of decalcification on the immunoreactivity of various antigens in formalin fixed tissues were examined. The pieces of fixed tissue were placed in four different decalcifying solutions (EDTA, formic acid, nitric acid, and Plank-Rychlo solution) for various time periods and then processed routinely and embedded in paraffin. The paraffin sections of the tissues were stained with immunoperoxidase methods for immunoglobulins, hormones, or tissue/tumor-specific markers. Sections of nondecalcified tissues were used as a control. The immunohistochemical staining intensity and the number of positive cells were not reduced significantly in decalcified tissues within the usual time period of routine decalcification procedures. Many antigens survived even prolonged decalcification. The results of this study indicate that routinely decalcified tissues can be used for immunoperoxidase staining without significant loss of immunoreactivity.

Decalcification Technique↗