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Biomedical subjects

S Fujimoto

Publications and source records attributed to S Fujimoto.

At least 667 records · Page 37Linked to original sources

Purification, characterization and inhibition of D-3-aminoisobutyrate aminotransferase from the rat liver.

D-3-Aminoisobutyrate-pyruvate aminotransferase was purified 2000-fold from rat liver extract using heat treatment, ammonium sulfate fractionation, carboxylmethyl-Sepharose CL-6B, DEAE-Sepharose CL-6B, hydroxyapatite, Sephacryl S-200 and electrofocusing chromatographies. The purified enzyme was shown to be homogeneous by gel electrophoresis both in the presence and absence of SDS. Its molecular mass, determined by gel filtration, was 220 kDa and the subunit molecular mass was 52 kDa. The enzyme exhibited absorption maxima at 280 nm and 412 nm with a shoulder at 330 nm at neutral pH. The pH optimum for enzyme activity was 9.5 and the Km values for beta-alanine and pyruvic acid were calculated to be 0.81 mM and 0.45 mM, respectively. The purified enzyme catalyzed the transamination of omega-amino acids; beta-alanine and D-3-aminoisobutyric acid served as good amino donors, and pyruvic acid, glyoxylic acid and oxaloacetic acid were favorable amino acceptors. 6-Azauracil and 6-azathymine were found to be potent inhibitors of purified rat liver D-3-aminoisobutyrate-pyruvate aminotransferase. 6-Azauracil acted as a competitive inhibitor with respect to beta-alanine, and was an uncompetitive inhibitor with respect to pyruvic acid with a Ki of approximately 8.9 mM.

Animals↗

Evidence for idiotypic- and antiidiotypic B-B cellular interaction with the use of cloned antiidiotypic B cell line.

Immunization of BALB/c mice with MOPC104E myeloma protein induces antiidiotypic B lymphocytes that have Id-specific enhancing activity on antibody production. The B-B cell interaction was restricted to both Igh and class II MHC. However, anti-Thy-1 and C-treated splenic B cells were maintained for more than 1 y in a mixture of Con A-stimulated splenocyte culture supernatant and synthetic medium. In applying the long term culture method, we have established a cloned B cell line named B19-1d, B19-1d cells are specific to MOPC104E or J558 cross-reactive Id and they express surface mu, lambda but no Ly-1. B19-1d do not spontaneously secrete Ig but produce them upon stimulation with bacterial LPS. The effect of B19-1d cell line on idiotypic antibody production was tested. Addition of only 10 to 100 B19-1d cells into dextran-immune B cell culture greatly enhanced the Id+ antidextran antibody responses. On the contrary, the antidextran antibody production was suppressed by the higher doses of B19-1d cells. The effective cooperation between dextran-immune B cells and B19-1d cloned B cells was restricted to class II MHC. The role of idiotypic- and antiidiotypic B-B cell interaction in immune regulation and repertoire generation was suggested.

Animals↗

Cadmium toxicity to the cornea of pregnant rats: electron microscopy and x-ray microanalysis.

Cadmium toxicity to the cornea of pregnant rats was studied using the electron microscope and x-ray microanalyzer. In in-vivo experiments, severe corneal edema occurred in pregnant dams that received intraperitoneal injections of cadmium sulphate for 4 days during gestation, but not in nonpregnant rats. Prominent swelling of mitochondria and the occurrence of intra- and intercellular vacuoles in the corneal endothelium were observed only in pregnant dams. In in-vitro experiments, electron-dense deposits consisting of cadmium-oxine complexes were preferentially found in swollen mitochondria of the endothelial cells. Cadmium peaks were obtained from these deposits with x-ray microanalysis. These data suggest that the corneal edema observed after administration of cadmium may imply the disturbance of pump function and barrier function of the corneal endothelium due to the primary toxic effects of this metal on mitochondria.

Animals↗

Prenatal diagnosis of fetal intracranial calcifications.

A case is presented wherein fetal intracranial calcifications as a result of intrauterine cytomegalovirus infection were visualized by computed tomography and magnetic resonance imaging at 36 weeks' gestation. Diagnosis of in utero cytomegalovirus infection was made by isolation of the virus from amniotic fluid. No symptomatic abnormality has been noted in the neonatal period except periventricular calcifications.

Adult↗

Cadmium toxicity in perinatal rat hepatocytes: electron microscopy, X-ray microanalysis, and morphometric analysis.

Effects of cadmium on the fetal and postnatal rat hepatocytes were studied with an electron microscope and an X-ray microanalyzer. Pregnant and lactating Wistar rat dams at 15 and 21 days of pregnancy and at 3 days after delivery received intraperitoneal injections of cadmium sulfate (1 mg/kg body weight) for 3 days. On the day following the last injection, the livers were isolated from the fetal and suckling rats and provided for electron microscopy. The livers from the untreated fetal and newborn rats served as control. Large bile canaliculi, which were formed by five or more hepatocytes, were frequently observed in the cadmium-treated perinatal rat livers. The intercellular space between each adjacent hepatocyte was widened. By X-ray microanalysis, cadmium peaks were preferentially detected out from intramitochondrial granules of the cadmium-treated hepatocytes. By morphometric analysis, the increase both in the mitochondria volume and in the number of intramitochondrial granules was evident in the cadmium-treated hepatocytes when compared to those of control. These data suggest the preferential accumulation of cadmium in mitochondria of the hepatocytes interferes with the morphogenesis of the perinatal rat liver.

Animals↗

Lymphomyeloid cells, susceptibility to erythrodermatitis of carp and bacterial antigens.

Pronounced changes occur in the kidneys carp injected with extracellular product (ECP), lipopolysaccharide (LPS) of A. salmonicida subsp. salmonicida, Freund's complete adjuvant (FCA). ECP caused 50-70% decrease in macrophages and neutrophils, whereas blasts and lymphocyte-like cells increased FCA-elicited increased percentages of blasts and a left shift of neutrophils after LPS injection. After both ECP and FCA injections, the density of major leucocyte types and red blood cells (RBC) in the kidney decreased. LPS generally increased the density of leucocytes. Granulocytes were larger after LPS injection and smaller after FCA injection than control cells. Perhaps ECP eliminates those cells potentially capable of nonspecific defense and FCA stimulates their proliferation. LPS seemed to induce mainly polyclonal lymphocyte-like cell propagation and a reduced replenishment of other leucocytes. Challenge morbidity was 100% of ECP-injected groups, 54.3% of controls, 37.1% of LPS-injected fish and 11.4% of FCA-injected groups. Disease susceptibility may be correlated with availability and functional status of macrophages and neutrophils.

Aeromonas↗

Positive results of combined therapy of surgery and intraperitoneal hyperthermic perfusion for far-advanced gastric cancer.

To evaluate the clinical efficacy of intraperitoneal hyperthermic perfusion (IPHP) for far-advanced gastric cancer, particularly with peritoneal seeding, we investigated the survival times of 59 patients who underwent distal subtotal gastrectomy, total gastrectomy, or total gastrectomy combined with concomitant resection of some of the remaining intra-abdominal organs. In all the 30 patients given IPHP, no cancer cells were present posthyperthermically in the lavage from the Douglas pouch. The 30 patients given IPHP lived longer than the 29 patients not given IPHP (p = 0.001), with a 1-year survival rate of 80.4% in the former group compared to 34.2% in the latter. With respect to a comparison of survival time of patients with peritoneal seeding, 7 patients not given IPHP had a 6-month survival rate of 57.1% and did not survive more than 9 months, whereas 20 patients given IPHP had 1- and 2-year survival rates of 78.7% and 45.0%, respectively; here the difference was significant (p = 0.001). The IPHP and control groups without peritoneal metastasis included 10 and 22 patients, respectively, and the 1-year survival rates are 85.4% and 45.3%, respectively. The survival rates of the former exceeded those of the latter, with p = 0.015 by the generalized Wilcoxon test. Thus this combined therapy offers the promise of extended survival for patients with far-advanced gastric cancer.

Combined Modality Therapy↗

Interstitial deletion of the short arm of chromosome 4 in a boy with mild psychomotor retardation and dysmorphism.

A 17-month-old boy is reported with 46,XY,del(4) (p15.2p15.32). He had mild psychomotor retardation and multiple minor anomalies, without growth retardation or microcephaly, which differs from the classical 4p--syndrome (Wolf-Hirschhorn syndrome). The activity of dihydropteridine reductase, a genetic marker for chromosome 4p15.3, was half that in a normal control.

Chromosome Deletion↗

Chromosomal studies on 934 induced abortuses of middle-aged pregnant women.

A total of 934 induced abortuses of middle-aged pregnant women (35-48 years old) were chromosomally surveyed. The mean gestational age was 7.6 +/- 2.0 (S.D.) weeks after the first day of the last menstrual period, and the mean maternal age was 39.6 +/- 2.7 (S.D.) years. There was a high incidence of chromosomally abnormal fetuses in induced abortions, which markedly increased with the advancing age of the women: 9.6% (40/418) for the 35-39-year-old age group, 20.7% (100/484) for the 40-44-year-old age group, and 43.8% (14/32) for the 45-48-year-old age group, averaging 16.5%.

Abortion, Induced↗

Acetylcholinesterase activity of developing muscles in the lower limb of the rat.

A cytochemical study of acetylcholinesterase was done in the lower limb of the prenatal rat and in the gastrocnemius muscle of the postnatal rat. Between 15 and 17 days of gestation, mesenchymal cells constituting the muscle primordia are characterized by the presence of enzyme activity in their rough endoplasmic cisterns and nuclear envelopes, while those involved in the formation of the neocapillary and cartilage do not show enzyme activity. This suggests that mesenchymal cells destined to myogenic cells actively produce acetylcholinesterase in a limited period, which may play a role in cellular aggregation and fusion during the muscular morphogenesis. Cytochemical findings as to extensive networks of secondary synaptic folds of the neuromuscular junctions and invaginations of the sarcolemma in the extrasynaptic regions are also illustrated in the differentiating gastrocnemius muscles.

Acetylcholinesterase↗

Holter electrocardiogram monitoring in nephrotic patients during methylprednisolone pulse therapy.

We assessed the effect of intravenous methylprednisolone pulse therapy (IMPT) on cardiac rhythm and electrolyte metabolism in patients with nephrotic syndrome. A total of 25 patients had valid evaluations with continuous ambulatory electrocardiograms, and 20 of these had simultaneous sodium and potassium clearances. No significant difference of frequency in complex ventricular arrhythmias (Lown's grades 3-5) between the control and the therapy period was observed; however, 4 patients showed complex ventricular arrhythmias including ventricular tachycardia (2 patients) during the course of therapy. Fractional excretion of potassium and serum potassium significantly increased from baseline after IMPT. Complex ventricular arrhythmias, sometimes leading to sudden death, might ensue from IMPT. These dysrhythmias may be related to an abrupt change in potassium reflux from the cell.

Adult↗

Endocrinological environment of polycystic ovarian disease.

Serum levels of androgenic hormones, 17-hydroxyprogesterone and estrone in Japanese patients with polycystic ovarian disease (PCOD) were elevated as compared to normal women. In early follicular phase of all of PCOD patients, serum levels LH were always higher than those of FSH. Serum PRL levels were shown to be significantly (p less than 0.05) higher in PCOD patients than in normal women. Although the cause of both inappropriate gonadotropin secretion and occurrence of mild hyperprolactinemia in PCOD have not been fully elucidated, decrease in numbers of receptor for dopamine is thought to be one of the main causes of them from the present data obtained by metoclopramide injection administered during the continuous infusion of dopamine.

Androgens↗

Factors contributing to blood pressure levels in chronic glomerulonephritis: an analysis of 105 biopsied patients.

Clinical data from 105 biopsied cases with chronic glomerulonephritis (CGN) were analyzed to determine factors contributing to blood pressure (BP) levels. Significant univariate correlations were found between BP and 11 parameters such as age, body mass index, pathological subgroup of CGN and creatinine clearance (Ccr). These were used as independent variables in multiple regression analysis, where five factors including Ccr and subgroups of CGN were significantly associated with BP. The results indicate that glomerular filtration and glomerular pathology contribute independently to BP levels in CGN.

Adult↗

Tyrosine formation from phenylalanine by ultraviolet irradiation.

When phenylalanine was irradiated at ultraviolet (UV) light, p-tyrosine, m-tyrosine and o-tyrosine were identified as hydroxylated products. From p-tyrosine and m-tyrosine, the formation of L-3,4-dihydroxyphenylalanine (DOPA) was observed. The hydroxylation of phenylalanine was prevented by radical scavengers, e.g., catalase, superoxide dismutase, sodium thiocyanate, mannitol, potassium iodide and thiourea. Replacement of air with nitrogen gas prevented the hydroxylation, but did not depress it completely. The addition of H2O2 increased significantly the hydroxylation of phenylalanine. These results suggest that the hydroxylation of phenylalanine by UV irradiation may be caused by .OH formed during the decomposition of H2O.

Hydroxylation↗

Accelerating effect of glutathione on hydroxylation of phenylalanine by stimulated polymorphonuclear leukocytes.

Sulfhydryl compounds significantly accelerated the hydroxylation of phenylalanine by stimulated polymorphonuclear leukocytes. The reduced form of glutathione (G-SH) was most effective. The hydroxylation reaction in the presence of G-SH was largely prevented by superoxide dismutase and hydroxyl radical scavengers. The results suggest that a much faster production of hydroxyl radical may occur in a reaction mixture containing both G-SH and stimulated polymorphonuclear leukocytes than in that containing stimulated polymorphonuclear leukocytes alone.

Animals↗

Effects of pimobendan, a cardiotonic and vasodilating agent with phosphodiesterase inhibiting properties, on isolated arteries and veins of rats.

Effects of pimobendan (PBD) were investigated on isolated rat blood vessels. PBD dose-dependently relaxed aortic, femoral arterial and mesenteric venous preparations precontracted with KCl and reduced the amplitude of spontaneous contractions of portal venous preparations; the sensitivity to PBD was femoral greater than portal greater than mesenteric greater than aorta. Relaxation response of the femoral artery to PBD was not changed by propranolol and aminophylline. Glyceryl trinitrate (GTN), isoproterenol (ISO), forskolin and adenosine also elicited dose-dependent relaxations of femoral arteries; the rank order of potency (mean negative log EC50 value) was GTN greater than ISO greater than PBD = forskolin greater than adenosine. The relaxation responses to PBD and isobutyl methylaxanthine (IBMX) were not attenuated with removal of endothelial cells. In the femoral artery, methylene blue diminished GTN-induced relaxation but not PBD-induced relaxation. PBD and IBMX increased the relaxation responses of the artery to cyclic AMP-forming drugs (ISO, forskolin and adenosine) but not a cyclic GMP-forming drug (GTN). PBD and IBMX increased the relaxation response of mesenteric veins to ISO. The drugs noncompetitively inhibited arterial contractions accompanied by voltage-dependent and alpha-adrenoceptor-operated Ca2+ influxes. In the absence of extracellular Ca2+, PBD and IBMX reduced contractile responses of arteries to norepinephrine but not caffeine. The present results suggested that PBD relaxed the blood vessels, at least in part, through an intracellular accumulation of cyclic AMP.

1-Methyl-3-isobutylxanthine↗