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Biomedical subjects

H Ueda

Publications and source records attributed to H Ueda.

At least 109 records · Page 6Linked to original sources
PubMed1993

3,4-Dihydroxychalcones as potent 5-lipoxygenase and cyclooxygenase inhibitors.

A novel series of 3,4-dihydroxychalcones was synthesized to evaluate their effects against 5-lipoxygenase and cyclooxygenase. Almost all compounds exhibited potent inhibitory effects on 5-lipoxygenase with antioxidative effects, and some also inhibited cyclooxygenase. The 2',5'-disubstituted 3,4-dihydroxychalcones with hydroxy or alkoxy groups exhibited optimal inhibition of cyclooxygenase. We found that 2',5'-dimethoxy-3,4-dihydroxychalcone (37; HX-0836) inhibited cyclooxygenase to the same degree as flufenamic acid and 5-lipoxygenase, more than quercetin. Finally, these active inhibitors of 5-lipoxygenase inhibited arachidonic acid-induced mouse ear edema more than phenidone.

Administration, Topical↗
PubMed1993

Delta opioid receptor mediates phospholipase C activation via Gi in Xenopus oocytes.

Cloned mouse delta-subtype opioid receptor (DOR1) was expressed in Xenopus oocytes to study the signal transduction. Opioid delta-agonists evoked a calcium-dependent chloride current in oocytes injected with mRNA derived from DOR1, together with that from the alpha subunit of Gi1. The delta-agonist-induced current was blocked by naltrindol, a delta-specific antagonist. The delta-agonist evoked no or very weak currents in oocytes with the alpha subunit of Gq or G(o). These findings indicate the functional coupling between the opioid delta-receptor and phospholipase C through an activation of Gi.

Analgesics↗
PubMed1993

Simple, rapid and simultaneous measurement of eight different types of carbamate pesticides in serum using liquid chromatography-atmospheric pressure chemical ionization mass spectrometry.

We have developed a method for simultaneous analysis of methylcarbamate pesticides in serum with an acute pesticide intoxication. This is performed by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry. Rapid detection of eight types of methylcarbamate pesticide can be achieved with this method, it only requires an extremely simple pre-treatment of the sample. The specificity of this method is equal to that of gas chromatography-mass spectrometry, and it satisfies the clinical requirements for detection sensitivity and specificity. Although some problems with this analytical method remain to be solved, we consider it to be superior to any other analytical method previously reported.

Acetates↗
PubMed1993

The presence of Ca(2+)-independent phospholipase A1 highly specific for phosphatidylinositol in bovine brain.

EDTA-insensitive phospholipase A activity hydrolyzing phosphatidylinositol was detected in a bovine brain soluble fraction. This phospholipase A was purified 25-fold by sequential chromatographies of DEAE-Toyopearl, Phenyl-Toyopearl, and Ultrahydrogel 1000. The partially purified EDTA-insensitive phospholipase A showed an apparent molecular mass of 230kDa on an Ultrahydrogel 1000 column in the presence of 0.05% Triton X-100 and a pH optimum at 7.0. The enzyme was highly specific for phosphatidylinositol; phosphatidylethanolamine and phosphatidylcholine were not hydrolyzed significantly. The enzyme activity was characterized as phospholipase A1, and Ca2+ and Mg2+ were not required for its activity. These results indicate the existence of Ca(2+)-independent, phosphatidylinositol-specific metabolism besides those catalyzed by Ca(2+)-dependent phospholipase A2 and Ca(2+)-dependent, phosphatidylinositol-specific phospholipase C.

Animals↗
PubMed1993

[MR cisternography using "long echo train length fast spin echo sequence" for demonstrating the inner ear].

Excellent quality of MR cisternography was acquired using "long echo train length fast spin echo sequence" (TR/TE = 2666/200, ETL = 24, 6 or 8 NEX, 3 mm thickness, 0 mm interslice gap, 19 cm FOV, 512 * 384, 2 DFT method). The inner ear anatomy such as canaliculus cochleae or lamina spiralis ossea were well visualized. The VII, VIII th nerve bundles within the internal auditory canal were detectable as 1 to 4 bundles. The vessels in the cerebellopontine angle or the internal auditory canal were also demarcated from the VII, VIII th nerve bundles because of their flow void. Signal to noise ratio seemed to be better than 3 DFT method, however limited spatial resolution in the cranio-caudal direction might require additional sagittal or coronal scan.

Adult↗
PubMed1993

Induced resistance and susceptibility to cerebral ischemia in gerbil hippocampal neurons by prolonged but mild hypoperfusion.

Brief periods of non-lethal cerebral ischemia can induce resistance against subsequent lethal ischemia. In this study, asymptomatic gerbils after unilateral carotid artery ligation were subjected to 5 min of forebrain ischemia. The prolonged but mild hypoperfusion, by carotid occlusion, induced susceptibility at 1 day and tolerance at 30 days to lethal ischemia in the hippocampal neurons. The neuroprotective effect correlated well with induction of heat shock protein 72 in the hippocampal neurons. These results suggested that neuronal cells possess a cellular response to sublethal hypoperfusion and can survive forthcoming ischemic stress.

Animals↗
PubMed1993

MHC-linked diabetogenic gene of the NOD mouse: molecular mapping of the 3' boundary of the diabetogenic region.

To localize and characterize the MHC-linked diabetogenic gene of the NOD mouse, we studied the class III region of the MHC in the NOD mouse and related strains. Hsp70, Bat5, Tnfa and Tnfb loci were studied by microsatellite polymorphism analysis and/or restriction mapping. The CTS mouse had the same allele as the NOD mouse at the Hsp70 locus, but different alleles at the Bat5, Tnfa and Tnfb loci from those of the NOD mouse. Our previous studies indicated that in the CTS mouse, class II MHC was the same as that of the NOD mouse, but that class I MHC was different at both K and D loci, and that CTS MHC was diabetogenic in the presence of NOD background genes. These data map major genetic susceptibility to type 1 diabetes to the segment flanked by class I K and class III Bat5 loci. Moreover, since the diabetogenic effect of the CTS MHC is weaker than that of the NOD MHC, these data suggest the presence of a second MHC-linked gene or gene complexes that modulate susceptibility to type 1 diabetes outside this segment.

Animals↗
PubMed1993

Immunocytochemical and immunogold localization of two prolactin isoforms in the same pituitary cells and in the same granules in the tilapia (Oreochromis mossambicus).

The tilapia pituitary secretes two forms of prolactin (tPRL) and a single growth hormone (tGH). The tPRLs share only 69% sequence identity and are designated tPRL177 and tPRL188 to indicate the number of amino acid residues in each isoform. Our aim was to develop specific antisera for detection of these three related polypeptides. Ten peptides corresponding to unique epitopes on the tPRLs and two peptides of tGH were synthesized using solid-phase methods, conjugated to carrier proteins, and used as immunogens for antibody production in rabbits. Select antisera for the tPRLs were highly specific, exhibiting only 1% cross-reactivity to the alternate tPRL under noncompetitive ELISA conditions at dilutions used in immunocytochemical analysis. The anti-tGH specifically bound to cells in the proximal pars distalis. Production of both tPRLs by a single cell type was indicated by the binding of both anti-tPRL177 and anti-tPRL188 to the same cells in the rostral pars distalis. Ultrastructural analysis of PRL-producing cells stained sequentially using the two different anti-tPRL antibodies labeled with immunogold of two size classes indicated that both tPRLs appear in the same granules. These findings suggest that the biological significance of two forms of PRL in the adult tilapia is not a function of differential regulation of two different classes of PRL cells or differential release of unique secretory granules.

Amino Acid Sequence↗
PubMed1993

Immunocytochemical study of membrane skeletons in abnormally shaped erythrocytes as revealed by a quick-freezing and deep-etching method.

Ultrastructures of membrane skeletons in spherocytic and elliptocytic erythrocytes were investigated immunocytochemically. Erythrocytes obtained from patients with hereditary spherocytosis (HS) and hereditary elliptocytosis (HE) were split open mechanically to obtain exposed cytoplasmic sides of erythrocyte membranes and were immunostained with anti-spectrin antibody. Replica membranes were prepared by a quick-freezing and deep-etching method and were checked by electron microscopy. The in situ membrane skeletons of normal erythrocytes consisted mainly of reticular patterns of spectrin filaments, which formed networks on the cytoplasmic sides of the cell membrane. In contrast, the membrane skeletons of abnormally shaped erythrocytes (HS and HE) were much less filamentous and more granular than those of normal erythrocytes. This abnormal organization in erythrocyte membrane skeletons may be one of the factors that induce abnormally shaped erythrocytes in HS and HE patients.

Adult↗
PubMed1993

EDTA-insensitive deacylation of phosphatidylinositol in porcine platelet membranes.

Pathways for EDTA-insensitive degradation of phosphatidylinositol (PI) were investigated in porcine platelet membranes and cytosol. The incubation of platelet membranes with [3H]glycerol-labeled PI in the presence of 2mM EDTA produced [3H]lysoPI and aqueous radioactive products, but not radioactive neutral lipids. The degradation in the membranes was optimal at pH8.0-9.0, while EDTA-insensitive hydrolysis was also observed in cytosol with optimal pH at pH7.0-9.0. The major water-soluble product was identified as glycerophosphoinositol. Under the conditions, [14C]arachidonate was released from 1-stearoyl-2-[14C]arachidonyl PI without accumulation of [14C]lysoPI. The deacylation activity preferred PI to phosphatidylcholine and phosphatidylethanolamine. Collectively, these results suggest that PI can be converted to lysoPI by phospholipase A2 in the absence of free Ca2+, providing the substrates for lysoPI-specific phospholipase C characterized earlier in porcine platelet membranes (Murase and Okuyama (1985) J.Biol.Chem. 260, 262-265).

Animals↗
PubMed1993

A microsatellite polymorphism in the human insulin receptor gene: a highly informative marker for linkage analysis.

To study genetic susceptibility to non-insulin dependent diabetes mellitus (NIDDM), association of insulin receptor gene, a candidate gene for NIDDM, with NIDDM was studied. A microsatellite polymorphism located in intron 2 of the human insulin receptor gene was detected by the polymerase chain reaction and used as a genetic marker. Eight different alleles were observed, indicating highly polymorphic nature of this marker. Although no association of this marker with NIDDM was observed in Japanese subjects, this marker will be useful for linkage studies of insulin receptor gene and genes located close to this gene on chromosome 19.

Alleles↗
PubMed1993

Immunocytochemical localization of copper-zinc superoxide dismutase in mouse olfactory mucosa.

Copper-zinc superoxide dismutase (Cu-Zn SOD) has been localized in mouse nasal mucosa. Immunocytochemical staining using polyclonal antibody against Cu-Zn SOD revealed endogenous Cu-Zn SOD in sustentacular cells in the olfactory area, and in ciliated epithelial cells in the respiratory area of the olfactory mucosa. Since these cells are located in the superficial portion of the olfactory mucosa, Cu-Zn SOD may serve as an intracellular antioxidant.

Animals↗
PubMed1993

Possible involvement of beta-PKC rather than that of alpha-PKC in differentiation of 3T3-L1 cells to adipocytes.

The change of subspecies of protein kinase C (PKC) was studied in 3T3-L1 cells in terms of their differentiation to adipocytes. 3T3-L1 cells feasible to differentiate to adipocytes by exposure to 3-isobutyl-1-methylxanthine (IBMX) and dexamethasone had both alpha- and beta-PKC. However, 3T3-L1 cells unfurnished with such feasibility had only alpha-PKC. alpha-PKC, therefore, seems to be more deeply involved in differentiation of 3T3-L1 cells to adipocytes than alpha-PKC.

1-Methyl-3-isobutylxanthine↗
PubMed1993

A possible pathway of phosphoinositide metabolism through EDTA-insensitive phospholipase A1 followed by lysophosphoinositide-specific phospholipase C in rat brain.

Incubation of [2-3H]glycerol-labeled phosphatidylinositol with a crude cytosol fraction of rat brain in the presence of EDTA yielded [3H]lysophosphatidylinositol predominantly without accumulation of labeled monoacylglycerol and diacylglycerol. The pH optimum of this phospholipase A activity was 8.0. The activity for phosphatidylinositol was twofold higher than for phosphatidylethanolamine, whereas phosphatidylcholine, phosphatidylserine, and phosphatidic acid were not hydrolyzed significantly under the conditions used. The phospholipase A activity for phosphatidylethanolamine was resolved in part from that for phosphatidylinositol by ammonium sulfate fractionation of the cytosol, indicating the existence of at least two forms of EDTA-insensitive phospholipase A. The positional specificity of the phosphatidylinositol-hydrolyzing activity was found to be that of a phospholipase A1, as radioactive lysophosphatidylinositol was produced from 1-stearoyl-2-[1-14C]arachidonyl-sn-glycero-3-phosphoinositol without release of free arachidonate. A phospholipase C activity specific for lysophosphoinositides was found in a membrane fraction from rat brain, which was similar to that characterized in porcine platelets. The phospholipase C was demonstrated to hydrolyze the 2-acyl isomer as well as the 1-acyl isomer of lysophosphatidylinositol. Taken together, our results suggest a possible pathway through which phosphatidylinositol is selectively degraded to the 2-acyl isomer of lysophosphatidylinositol in a Ca(2+)-independent manner, and subsequently converted to a 2-monoacylglycerol in rat brain.

Animals↗
PubMed1993

Syntheses and inhibitory effects on gastric lesions of 4-guanidinomethylbenzoic acid arylamides.

A novel series of 4-guanidinomethylbenzoic acid (GMBA) arylamides was synthesized. Several showed more potent inhibitory effects on stress-induced gastric lesion in rats than cetraxate. We selected 4-guanidinomethylbenzoic acid (2'-ethoxycarbonyl)phenylamide 3 for further pharmacological assessments because it had low toxicity. Compound 3 showed significant inhibitory effects on stress-, HCl-ethanol- and indomethacin-induced gastric lesions and gastric secretion, the ED50 values being 34.4, 45.0 and 23.0 mg/kg (p.o.) and 240 mg/kg (i.d.), respectively. Furthermore, this compound restored the reduction of gastric mucus caused by the stress-loading and inhibited compound 48/80-induced ulcer.

Animals↗
PubMed1993

Serum collagenase-like peptidase activity correlated with bone mineral density. A study of 102 elderly women.

To clarify the relationship between collagenase-like peptidase (CL-peptidase) and bone metabolism, serum CL-peptidase activity and bone mineral density (BMD) in the lumbar spine, measured by dual energy X-ray absorptiometry (DEXA), were determined in 102 women with a mean age of 70 (41-94) years. The serum activity of CL-peptidase increased slightly with age up to the 8th decade, and then decreased. Next, we classified the subjects into the following 2 groups by age: a postmenopausal group 50-69 years, and an elderly group over 70 years. In the younger group serum CL-peptidase activity did not correlate with BMD, while in the elderly it did. Our result suggests that serum CL-peptidase activity may reflect bone resorption in elderly women.

Adult↗
PubMed1993

[The effect on age for the relationship between hypertension and glucose intolerance].

Recently, high frequencies of glucose intolerance and insulin resistance have been reported in patients with hypertension. However, both blood pressure and glucose tolerance are influenced by age. To investigate the effect of age on the interaction between blood pressure and glucose tolerance, we analyzed blood pressure and glucose tolerance in otherwise healthy subjects (n = 576) who underwent an oral glucose tolerance test and blood pressure measurement as a part of a healthy care program. The prevalence of DM and IGT were significantly higher in the hypertensive group than in the normotensive group. When the subjects were divided into three groups according to their age (less than 50 years old, between 50 and 60 years old and more than 60 years old), the prevalence of glucose intolerance (DM or IGT) was significantly higher in the hypertensive group than in the normotensive group in subjects under 50 years old, but not in subjects between 50 and 60 years old or over 60 years old. In the subjects classified as having normal glucose tolerance, the incremental area of glucose under the curve of 75g-OGTT was significantly higher in the hypertensive group than in the normotensive group. These data suggest that hypertension is associated with glucose intolerance in Japanese population and that age significantly affects this interaction.

Aged↗