Biomedical subjects

H Okuda

Publications and source records attributed to H Okuda.

At least 163 records · Page 9Linked to original sources

PubMed1997

[Inhibitive effect of umbellatus polyporus polysaccharide on cachexic manifestation induced by toxohormone-L in rats].

OBJECTIVE: To investigate the effect of treatment of cachexia with Umbellatus Polyporus Polysaccharide (UPP). METHODS: UPP was used to treat cachexia induced by toxohormone-L. RESULTS: Toxohormone-L from ascites fluid with primary hepatoma could induce lipolysis in vitro significantly, inhibit the intake behavior, decrease the level of blood zinc, increase that of blood copper (P < 0.01), upp could inhibit these effects. CONCLUSION: Toxohormone-L was closely related with neoplastic cachexia and UPP could inhibit this effect induced by toxohormone-L significantly.

Animals↗

PubMed1996

Recombinant human tumour necrosis factor-alpha suppresses synthesis, activity and secretion of lipoprotein lipase in cultures of a human osteosarcoma cell line.

The effect of recombinant human tumour necrosis factor-alpha (TNF-alpha) on synthesis, activity and secretion of lipoprotein lipase (LPL) was examined using a human osteosarcoma cell line, osteosarcoma Takase (OST). Treatment of OST cells with TNF-alpha decreased LPL synthesis, resulting in a decrease in expression of activity and secretion of LPL. When OST cells were incubated with glycerol tri[1-14C]palmitate, TNF-alpha decreased dose- and time-dependently the production of 14CO2 and the amounts of radioactivity incorporated into cellular triacylglycerol and phospholipid. The similar reduction of synthesis and activity of LPL as suppression of CO2 production and cellular lipid synthesis indicated that the suppression of 14CO2 production and 14C-labelled lipid synthesis was secondary. TNF-alpha also suppressed expression of proliferating cell nuclear antigen, indicating that it had an anti-proliferative activity on OST cells. The findings suggest that one cause of the anti-proliferative activity of TNF-alpha is the suppression of the LPL-mediated supply of non-esterified fatty acids as an energy source for growth.

Bone Neoplasms↗

PubMed1996

Characterization of the Duffy gene promoter: evidence for tissue-specific abolishment of expression in Fy(a-b-) of black individuals.

We have previously identified a novel first exon of Duffy gene and two inverse GATA motifs in the 600 bp 5' flanking region. The proximal GATA is positioned downstream from the start position of endothelium and upstream from that of erythroid. One base substitution (-365T --> C) was found in the proximal GATA motif from three black Fy(a-b-) individuals, and was regarded as a common polymorphic mutation in black Fy(a-b-) individuals. The upstream sequence of the novel first exon was inserted in the upstream of chloramphenicol acetyltransferase (CAT) gene and transfected in human erythroleukemia cell line (HEL) and human microvascular endothelial cells (HMvEC). The black type mutation abolished the CAT transcription in HEL cells but not in HMvEC. Deletion mutagenesis study revealed that the proximal GATA motif represent the erythroid regulatory core region for Duffy gene. Gel shift assay showed that the proximal GATA motif is the target sequence of GATA-1. These studies indicate that the black type mutation abolishes Duffy gene expression in erythroid but not in postcapillary venule endothelium, which is compatible with the Northern blot and immunohistochemical observation in black Fy(a-b-) individuals.

Base Sequence↗

PubMed1996

Coenzyme A-independent monoacylglycerol acyltransferase from rat intestinal mucosa.

Rat intestinal mucosa contains high diacylglycerol-synthesizing activity (monoacylglycerol acyltransferase (MGAT) activity) due to monoacylglycerol and fatty acid, independently of coenzyme A and ATP. MGAT activity was purified from rat intestinal mucosa by successive chromatography separations on DEAE-cellulose, CM- Sephadex, and anti-IgG-Sepharose against rat pancreatic lipase. The enzyme was electrophoretically homogeneous, and its molecular weight was 49,000, which is identical with that of rat pancreatic lipase. Immunoblotting analysis with antibody against rat pancreatic lipase showed one immunoreactive protein with an estimated molecular weight of 49,000. The activity of the purified enzyme was completely inhibited by addition of the antibody. Using immunocytochemical techniques, it was found that immunoreactive protein against rat pancreatic lipase was uniformly distributed within the absorptive cells of the intestine but was absent from the microvillar membrane. The MGAT activity of intestinal mucosal homogenate was inhibited by about 65% by addition of antibody against rat pancreatic lipase. Trioleoylglycerol- and dioleoylglycerol-hydrolyzing activities of the purified enzyme and pancreatic lipase were inhibited by addition of intestinal mucosa extract. These results suggest that pancreatic lipase is present in intestinal absorptive cells and that it may contribute to resynthesis of diacylglycerol from monoacylglycerol and fatty acids in these cells.

Acyltransferases↗

PubMed1996

Effects of soluble sodium alginate on cholesterol excretion and glucose tolerance in rats.

We studied the effects of a natural sodium alginate (isolated from Laminaria angustata Kjellman var. longissima Miyabe, Phaeophyceae) (average molecular weight: 2700 kDa; AG-270) and three water-soluble low-molecular weight sodium alginates (average molecular weights, 10, 50 and 100 kDa; AG-1, AG 5, and AG-10, respectively) on cholesterol excretion and glucose tolerance in rats. AG-270, AG-5 and AG-10 enhanced cholesterol excretion into faeces. AG-270 and AG-10 inhibited blood glucose and insulin levels from rising 30 min after glucose administration. AG-5 inhibited the blood glucose level from rising 30 and 60 min after glucose administration, without affecting blood insulin levels. AG-1 had no effect on cholesterol excretion or glucose tolerance. These findings suggest that the effects of the natural sodium alginate and AG-5 and AG-10 on cholesterol excretion and glucose tolerance may be due to the inhibition of cholesterol and glucose absorption from the small intestine by the gelling of the free alginic acid converted in the stomach. These experimental results indicate that the low-molecular weight sodium alginates, AG-5 and AG-10, should be useful as dietary fibers for the prevention of obesity, hypercholesterolemia, and diabetes.

Administration, Oral↗

PubMed1996

A novel phenylserine dehydratase from Pseudomonas pickettii PS22: purification, characterization, and sequence of its phosphopyridoxyl peptide.

A novel phenylserine dehydratase [EC 4.2.1.-], which catalyzes the deamination of L-threo-3-phenylserine to yield phenylpyruvate and ammonia, was purified to homogeneity from a crude extract of Pseudomonas pickettii PS22 isolated from soil. The enzyme was a monomer having a molecular mass of about 38 kDa and contained 1 mol of pyridoxal 5'-phosphate per mol of enzyme. The enzyme exhibited absorption maxima at 279 and 416 nm. No appreciable spectral change was observed over the pH range of 6.0 to 8.0. The maximal reactivity was obtained at about pH 7.5. The enzyme was highly specific for L-threo-3-phenylserine (Km, 0.21 mM). L-erythro-3-Phenylserine, L-threonine, L-serine, and D-serine were inert. The enzyme was inhibited by phenylhydrazine, hydroxylamine, p-chloromercuribenzoate, and HgCl2, but not by L-isoleucine, L-threonine, or L-serine. AMP, ADP, and ATP did not affect the enzyme activity. The N-terminal amino acid sequence was not similar to those of biosynthetic and biodegradative L-threonine dehydratases and L-serine dehydratases. The isolated tryptic phosphopyridoxyl peptide, however, contained a pyridoxal 5'-phosphate-binding consensus amino acid sequence of amino acid dehydratases.

Amino Acid Sequence↗

PubMed1996

Beta-Adrenergic receptors in rat fat cells and their relationship with lipolysis.

Norepinephrine stimulated lipolysis in rat fat cells while (-)-alprenolol completely inhibited this lipolysis. (-)-Alprenolol competed for (-)-[3H] dihydroalprenolol (DHA) binding sites on rat fat cells. The specific (-)-[3H]DHA binding sites identified by competition with (-)-alprenolol were found to be transferred to the solubilized supernatant during preparation of endogenous lipid droplets from the fat cells. Although the lipid droplets did not exhibit specific (-)-[3H]DHA binding, norepinephrine induced lipolysis in a cell-free system consisting of the lipid droplets and hormone-sensitive lipase (HSL). Norepinephrine-induced lipolysis in the cell-free system was inhibited by propranolol and (-)-alprenolol, but not by phenoxybenzamine. The lipolytic action of norepinephrine and the anti-lipolytic actions of propranolol and (-)-alprenolol disappeared after sonication of the lipid droplets in the cell-free system. These results suggest that the adrenergic receptor concerned with lipolysis in fat cells may not be a specific (-)-[3H]DHA binding site, but may be closely related to the lipid droplets.

Adipocytes↗

PubMed1996

Ginsenosides increase secretion of lipoprotein lipase by 3T3-L1 adipocytes.

Treatment of 3T3-L1 adipocytes with either an oleanolic acid glycoside or a 20(S)-protopanaxatriol glycoside increased the secretion of lipoprotein lipase activity into the medium dose-dependently. At a concentration of 100 micrograms/ml, ginsenosides Ro, Re, Rg1, and Rh1 increased the secretion of lipase activity into the medium by 119, 107, 56, and 32%, respectively. The ratio of lipase activity in the medium to cellular lipase activity was 4.7% in control cells and 8.6% in ginsenoside Ro-treated cells, 8.3% in ginsenoside Re-treated cells, 7.0% in ginsenoside Rg1-treated cells, and 6.3% in ginsenoside Rh1-treated cells. Ginsenoside Rb2, which is a 20(S)-protopanaxadiol glycoside, increased the secretion of lipase activity by 16% at 25 micrograms/ml, and the ratio of lipase activity in the medium to cellular lipase activity was higher in ginsenoside Rb2-treated cells than in control cells. However, at 100 and 200 micrograms/ml, ginsenoside Rb2 decreased the secretion of lipase activity in parallel with cellular lipase activity. Ginsenoside Rd also decreased the secretion of lipase activity in the same dose-dependent manner. Thus, the effective dose for the secretion of lipoprotein lipase activity with ginsenosides varies with their aglycone structure.

3T3 Cells↗

PubMed1996

Studies on the inhibition of pancreatic and carboxylester lipases by protamine.

The basic protein protamine strongly inhibited hydrolysis of triolein emulsified with soybean phosphatidylcholine (PC) by pancreatic and carboxylester lipases; 10 micrograms/ml protamine, about 1000 times lower than the concentration of bovine serum albumin for the same effect, inhibited triolein hydrolysis completely. This inhibition was not affected by the incubation pH or bile salt concentration. Two other basic proteins, histone and purothionin, also inhibited hydrolysis of triolein emulsified with soybean PC, but they did not inhibit triolein hydrolysis by gastric lipase. When gum arabic was used as an emulsifier instead of soybean PC, these basic proteins did not affect triolein hydrolysis by pancreatic or carboxylester lipases. The effects of protamine on triolein hydrolysis by pancreatic and carboxylester lipases was studied using various phospholipids as emulsifiers. Protamine (10 micrograms/ml) did not inhibit hydrolysis of triolein emulsified with dicaproyl PC (DCPC), phosphatidic acid (PA), or phosphatidylserine (PS) by pancreatic and carboxylester lipases. Conversely, protamine at high concentrations slightly stimulated hydrolysis of triolein emulsified with DCPC or PA. Hydrolysis of triolein-phosphatidylethanolamine (PE) emulsion was inhibited slightly by protamine. The profiles of protamine inhibition of triolein-phosphatidyl-N,N-dimethyl ethanolamine (PDME) and triolein-phosphatidyl-N-monomethyl ethanolamine (PMME) emulsions were intermediate between those of PC and PE emulsions. These results suggest that the phospholipid species, especially choline moieties and fatty acid chain length, affect the lipase inhibitory activity of protamine profoundly. In vivo, oral administration of protamine to rats reduced and delayed the peak plasma triacylglycerol concentration, but neither bovine serum albumin nor an amino acid mixture with an amino acid composition identical to protamine affected plasma triacylglycerol levels.

Animals↗

PubMed1996

[Development of deep vein thrombosis in an aplastic anemia patient with antiphospholipid antibodies].

A 38-year-old female was admitted to our hospital because of pancytopenia in April 1992. She was diagnosed as aplastic anemia by bone marrow biopsy and other examinations. Then she was treated with methyl-prednisolone pulse therapy followed by administration of cyclosporin in out-patient clinic. Though the modest improvement of peripheral blood count was observed, the worsening of pancytopenia was developed in association with tapering of cyclosporin. Anabolic steroid was given from June 1994 and gradual improvement of peripheral blood count was observed. On June 1995, she developed sudden onset of swelling and discoloration of a lower extremity, and thrombosis in the femoral vein was detected by Doppler ultrasonography. She was positive for lupus anticoagulant and anticardiolipin antibody, thus a diagnosis of antiphospholipid syndrome was made. Aplastic anemia associated with antiphospholipid syndrome has never been reported as far as we know. This case will be of importance for analyzing the cause of thrombosis in aplastic anemia.

Adult↗

PubMed1996

[Effect of FUT-187, oral serine protease inhibitor, on inflammation in the gastric remnant].

Excessive enterogastric reflux following partial gastrectomy is believed to be responsible for the cause of inflammation in the gastric remnant. We examined the effect of FUT-187, a synthetic serine protease inhibitor, on symptoms and endoscopic findings in 33 patients who were diagnosed endoscopically as postgastrectomy gastritis. Patients took 50 mg FUT-187 orally after each meal and at bedtime for 8 weeks. Before treatment, 30 patients (91%) suffered from several symptoms including regurgitation and/or bitter taste in the mouth (49%), epigastric pain (42%) and nausea (36%). From endoscopic observation, erythema was detected in 32 patients, edema in 23 patients and erosion and/or ulcer in 9 patients. After treatment the global improvement rating for subjective symptoms was 76.7% (23/30) and the improvement of endoscopic findings was 63.6% (21/33). Diarrhea was observed in one patient but could be easily controlled by discontinuation of the drug. Our results suggest that FUT-187 can be a useful drug for the treatment of postgastrectomy gastritis with its efficacy and safety.

Administration, Oral↗

PubMed1995

A subfamily 2 homo-dimeric glutathione S-transferase mYrs-mYrs of class theta in mouse liver cytosol.

A homo-dimeric subfamily 2 glutathione (GSH) S-transferase (GST) mYrs-mYrs of the class theta was isolated from mouse liver cytosol and purified to homogeneity. The first 28 N-terminal amino acid sequence of the GST was completely identical to that of rat subfamily 2 GST Yrs-Yrs of the class theta. GST mYrs-mYrs cross-reacted with anti-rat GST Yrs-anti-sera but not with anti-sera raised against rat GSTs Ya-Ya (alpha), Yb1-Yb1 (mu), and Yp-Yp (pi) and represented more than 95% of the mouse liver cytosolic GST activity to scavenge the reactive sulfate ester 5-sulfoxymethylchrysene of the potent carcinogen 5-hydroxymethylchrysene. The mouse class theta GST had little activity toward 1-chloro-2,4-dinitrobenzene and was unretainable on GSH and an S-hexyl-GSH affinity columns. GST mYrs-mYrs had a much higher GSH peroxidase activity toward fatty acid hydroperoxides than did the other classes of mouse GSTs.

Amino Acid Sequence↗

PubMed1995

Reduced dimerization of lipoprotein lipase in post-heparin plasma of a patient with hyperchylomicronemia.

As in post-heparin plasma of control subjects, post-heparin plasma of a patient with hyperchylomicronemia contained lipoprotein lipase (LPL) subunits with M(r) = 57,000. But although the amount of LPL was the same as in post-heparin plasma of controls, no LPL activity was detectable. Nearly all the LPL in post-heparin plasma of controls bound to heparin-Sepharose and this LPL bound was mainly eluted with 1.5 M NaCl in parallel with the activity. In post-heparin plasma of the patient, 58% of the LPL subunits did not bind to heparin-Sepharose and 23% was eluted with 0.6 M NaCl. Studies by sucrose density gradient centrifugation showed that almost all the LPL in post-heparin plasma of controls was recovered in the peak with a sedimentation coefficient of 6.8 S, corresponding to the position of a dimeric form of LPL, in parallel with the activity; little LPL was recovered in the peak with a sedimentation coefficient of 4.0 S, corresponding to the position of a monomeric form of LPL. In post-heparin plasma of the patient, 35% of the LPL subunits was recovered in fractions with larger sedimentation coefficients at the bottom of the centrifuge tube, indicating the presence of an aggregated form(s) of LPL; the amount of the monomeric form of LPL was increased, while that of the dimeric form was decreased. Thus, defect of LPL activity in post-heparin plasma of the patient with hyperchylomicronemia could result from reduced dimerization of LPL subunits.

Adolescent↗

PubMed1995

Mechanism of increase in basal lipolysis of enlarged adipocytes in obese animals.

Sonication of rat fat cells caused an increase in lipolysis in the absence of lipolytic hormones (basal lipolysis) and loss of epinephrine responsiveness. Sonication of endogenous lipid droplets from fat cells also induced an increase in lipolysis in the presence of HSL. Addition of phosphatidylcholine to the sonicated lipid droplets reduced the hydrolysis of triglyceride by HSL. These results suggest that the active HSL is already present in the fat cell even in the absence of lipolytic hormone, and phosphatidylcholine on the surface of endogenous lipid droplets causes inhibition toward lipolytic action of HSL. The decrease in the surface phosphatidylcholine concentration in endogenous lipid droplets was proved to cause the increase in basal lipolysis. It is demonstrated that basal lipolysis was elevated in the enlarged fat cells of obese rats by reduction of surface phosphatidylcholine concentration of the endogenous lipid droplets.

Adipocytes↗

PubMed1995

Reverse correlation between P-glycoprotein expression and proliferative activity in endometrial adenocarcinoma.

Immunohistochemical study was employed using a monoclonal antibody (C219) to investigate P-glycoprotein expression in 23 normal endometria and 40 endometrial adenocarcinomas. P-glycoprotein immunopositivity was observed in the mid- to late-proliferative phase and the whole secretory phase of normal endometrium. In contrast, no P-glycoprotein was detected in endometrium of early proliferative phase nor post-menopausal endometrium. We also investigated the expression of P-glycoprotein in endometrial cancers to find 16 out of the 40 endometrial adenocarcinomas (40%) expressed P-glycoprotein. P-glycoprotein immunopositivity was often observed in gland growing parts but not in solid growing parts in a given tumor specimen. Proliferative activity of the tumor, as measured by PCNA labeling, was significantly higher in the P-glycoprotein-negative group than that in P-glycoprotein-positive group (P < 0.005). Thus, there was a strong reverse relation between P-glycoprotein expression and proliferative activity in endometrial adenocarcinomas.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1995

Epidemiological and clinical features of Budd-Chiari syndrome in Japan.

The Japanese Ministry of Health and Welfare Research Committee on Aberrant Portal Blood Flow carried out an epidemiological survey and clinical study on Budd-Chiari syndrome in 1990. In the primary survey for determining the prevalence of the disease, a questionnaire was sent to all major hospitals throughout Japan and 160 cases seen in 1989 were compiled. More epidemiological details were obtained in 87 of these 160 cases. The number of patients with Budd-Chiari syndrome in this country was estimated to be about 300 (prevalence of 2.4/million) with about 20 new cases occurring every year. In the clinical study, 157 authentic cases of Budd-Chiari syndrome studied in 15 years (1975-89) were analyzed. There were 87 males (average age, 36.4 years) and 70 females (46.5 years), and the average period from the likely onset to the first medical consultation was 6.6 years, suggesting that these patients were mostly chronic cases. The main clinical features were hepatomegaly, leg edema, ascites and venous dilatation over the trunk. Abdominal pain was recorded in only four (2.5%). There were 16 (10.2%) with known identifiable etiologies. Of the patients 93% showed an obstructing lesion of various thickness in the hepatic portion of the inferior vena cava. Only nine (5.7%) had hepatic vein obstruction without caval lesions. Thus, the majority of Budd-Chiari syndrome patients in Japan are idiopathic, having an obstructing lesion in the inferior vena cava. The main causes of 33 deaths (21%) were liver failure, variceal bleeding and hepatocellular carcinoma. Hepatocellular carcinoma occurred in 10 (6.4%) in the 15-year period. However, the incidence of Budd-Chiari syndrome among all cases of hepatocellular carcinoma was less than 1% in the survey made by the Liver Cancer Study Group of Japan.

Adult↗

PubMed1995

Immunocytochemical localization of nicotinic acetylcholine receptor in rat cerebral cortex.

Localization of nicotinic acetylcholine receptor (nAChR) alpha 4 subunits was investigated in rat cerebral cortex using a monoclonal antibody against alpha 4 subunits. The antibody depleted more than 70% of the [3H]methylcarbamylcholine choline binding activity of the solubilized membrane fraction. By light microscopy alpha 4-like immunoreactivity (alpha 4-LI) was found through layers II to VI. The immunostaining was the most prominent in cell bodies and apical dendrites of pyramidal cells in layer V. By electron microscopy most immunoreaction products were observed in the rough endoplasmic reticulum, cytoplasmic matrix and synaptic membranes. Alpha 4-LI was detected in the postsynaptic membranes of neuronal cell bodies and apical dendrites. These findings suggest that alpha 4-containing subtypes serve as one possibly the postsynaptic nAChR in rat cerebral cortex.

Animals↗

PubMed1995

Effects of stilbenes isolated from medicinal plants on arachidonate metabolism and degranulation in human polymorphonuclear leukocytes.

Studies were made on the effects of stilbene derivatives isolated from medicinal plants on arachidonate metabolism and degranulation in human polymorphonuclear leukocytes (PMN-L). Resveratrol (3,4',5-trihydroxystilbene) isolated from the roots of Reynoutria japonica was found to inhibit the 5-lipoxygenase products 5-hydroxy-6,8,11,14-eicosatetraenoic acid (5-HETE), 5,12-dihydroxy-6,8,10,14-eicosatetraenoic acid (5,12-diHETE) and leukotriene C4(LTC4); its concentrations for 50% inhibition (IC50) were 8.90 x 10(-6) M, 6.70 x 10(-6) M and 1.37 x 10(-6) M, respectively. The IC50 of 5-HETE, 5,12-diHETE and LTC4 formations of synthetic 3,3',4-trihydroxystilbene were 5.90 x 10(-6) M, 6.30 x 10(-7) M and 8.80 x 10(-7) M, respectively. Moreover, they inhibited the release of lysosomal enzyme such as lysozyme and beta-glucuronidase induced by calcium ionophore A 23187 from human PMN-L at 10(-3)-10(-4) M.

Arachidonic Acid↗