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Biomedical subjects

K Higashino

Publications and source records attributed to K Higashino.

At least 109 records · Page 6Linked to original sources
PubMed1995

Enzyme-linked immunosorbent assay (ELISA) for Aleuria aurantia lectin-reactive serum cholinesterase to differentiate liver cirrhosis and chronic hepatitis.

We have established an enzyme-linked immunosorbent assay (ELISA) for total serum cholinesterase (ChE) using 2 new monoclonal antibodies (mAbs) to ChE (E.C.3.1.1.8). The ELISA results correlated very well with the results of a serum ChE activity assay, which has been widely used for differentiating patients with liver diseases, such as hepatocellular carcinoma, liver cirrhosis and chronic hepatitis, from normal individuals. We next established an ELISA for Aleuria aurantia lectin (AAL)-reactive serum ChE using one of the anti-ChE mAbs and AAL, which specifically recognizes L-fucose alpha 1-->2, L-fucose alpha 1-->3, and L-fucose alpha 1-->6 structures. The ratio of AAL-reactive ChE to total ChE in sera determined by the two ELISA procedures was increased in patients with hepatocellular carcinoma and liver cirrhosis compared with patients with chronic hepatitis and normal individuals. We then applied the ELISA for AAL-reactive ChE directly to 10-fold-diluted serum samples, and by using a cut-off value of the mean + 2S.D. for normal individuals, we could effectively differentiate liver cirrhosis from chronic hepatitis. This single ELISA for AAL-reactive ChE could be a useful aid in clinical diagnosis.

Antibodies, Monoclonal↗
PubMed1995

Determination of plasma purine nucleoside phosphorylase activity by high-performance liquid chromatography.

A high-performance liquid chromatographic method was developed for the determination of plasma purine nucleoside phosphorylase activity. In this method, the reaction mixture consisted of 15 microliters of plasma and 285 microliters of 50 mM phosphate buffer (pH 7.4) containing 3.8 mM inosine and 0.15 mM 2-(3-cyano-4-isobutoxyphenyl)-4-methyl-5-thiazolecarboxylic acid (strong xanthine oxidase inhibitor). After the reaction, the hypoxanthine produced was monitored to express plasma purine nucleoside phosphorylase activity. By this method, the activity of purine nucleoside phosphorylase was easily determined even with a small-volume plasma sample and despite its low activity in plasma. In addition, plasma purine nucleoside phosphorylase activity can be accurately determined even if the plasma is turbid. As a result, we were able to measure plasma purine nucleoside phosphorylase activity in patients with gout or asthma and healthy subjects, whereby it was demonstrated that plasma purine nucleoside phosphorylase activity was higher in patients with asthma than in either healthy subjects or patients with gout.

Adult↗
PubMed1995

Vascular smooth muscle cell-derived, Gla-containing growth-potentiating factor for Ca(2+)-mobilizing growth factors.

Proliferation of vascular smooth muscle cells (VSMC) is triggered by two types of growth factors. One activates tyrosine kinase-type receptors and the other activates G-protein-coupled receptors. We found that a conditioned medium of rat VSMC contained a growth-potentiating activity for the latter type of growth factor, and we purified a 70-kDa growth-potentiating factor (GPF) from the conditioned medium. Analyses of GPF and its cDNA revealed GPF to be a gamma-carboxyglutamic acid-containing protein encoded by a growth arrest-specific gene, gas6, which related to protein S. GPF specifically potentiated cell proliferation mediated by Ca(2+)-mobilizing receptors. The presence of a specific binding site suggests that the effect of GPF is mediated by a receptor. Thus, GPF may be a new type of extracellular factor regulating VSMC proliferation.

Amino Acid Sequence↗
PubMed1995

Ethanol as a xanthine dehydrogenase inhibitor.

In the present study, we investigated whether ethanol inhibits the activity of xanthine dehydrogenase. Ethanol and/or inosine were administered to normal subjects, and plasma concentration and urinary excretion of purine bases were measured together with blood concentrations of lactic acid and pyruvic acid. In addition, ethanol and pyrazinamide were administered to these subjects, and plasma concentration and urinary excretion of pyrazinamide and its major metabolites were measured. Increases in plasma concentration and urinary excretion of xanthine induced by a combination of ethanol and inosine were greater than the sums of increases induced separately by ethanol and inosine, although increases in plasma concentration and urinary excretion of uric acid induced by the combination of ethanol and inosine were not different from the sums of increases induced separately by ethanol and inosine. Ethanol increased the ratio of blood lactic acid to blood pyruvic acid and decreased plasma concentration and urinary excretion of 5-hydroxypyrazinamide and 5-hydroxypyrazinoic acid. These results suggest that ethanol inhibits xanthine dehydrogenase presumably by an ethanol-induced increase in the cytosolic concentration of NADH in the liver.

Acetates↗
PubMed1995

Predominant expression of invariant V alpha 14+ TCR alpha chain in NK1.1+ T cell populations.

A novel T cell subset characterized by cell surface NK1.1+ TCR alpha beta+ expression was investigated for its TCR alpha usage, particularly that of invariant V alpha 14 TCR, which was found to be preferentially used in peripheral CD4-CD8- T cells developed at extrathymic sites. We found that NK+ alpha beta T cell subsets account for 0.4% in thymocytes, 5% in the splenic T cells and 40.5% in the bone marrow T cells. Among these NK+ alpha beta T cells, two distinct subsets were detected; cell surface TCR V alpha 14+ and V alpha 14- subpopulations. Almost all of NK+ alpha beta thymocytes express V alpha 14 mRNA; however, only < 20% were positive, while > 80% were negative or undetectable for V alpha 14 TCR expression on the cell surface in the thymus. Similarly, approximately 50% of NK+ alpha beta T cells in spleen and bone marrow are V alpha 14+ as revealed by FACS. TCR repertoire analysis by nucleotide sequences on inverse PCR products demonstrated that most NK+ alpha beta T cells express an invariant TCR encoded by the V alpha 14J alpha 281 gene with a 1 base N-region in all tissues. Thus, invariant V alpha 14 TCR is uniquely expressed on NK T cells, and can be a marker to distinguish NK, NK T and T cells.

Animals↗
PubMed1995

Increased concentrations of serum Lp(a) lipoprotein in patients with primary gout.

OBJECTIVES: To investigate if serum Lp(a) lipoprotein (Lp(a)), a risk factor for atherosclerotic diseases, increases in patients with gout, who frequently also have atherosclerotic disease. METHODS: Fasting blood samples were taken for measurement of Lp(a) and other variables in 175 male patients with primary gout. Serum concentrations of Lp(a) were measured by enzyme linked immunosorbent assay. The median value and frequency distribution of Lp(a) in gout patients were compared with those in 172 control male subjects. In addition, we examined the effect of niceritorol on serum Lp(a) values in gout patients in whom the Lp(a) concentration was greater than 20 mg/dl. RESULTS: Serum Lp(a) was significantly higher in patients with gout than control subjects (median 15.5 mg/dl upsilon 8.6 mg/dl; p < 0.01). The frequency distribution of Lp(a) in gout was significantly shifted towards greater concentrations compared with control, although skewed distribution was noted in both groups. Serum Lp(a) concentration was not related to age, body mass index, alcohol intake, creatinine, fasting blood sugar or uric acid in patients with gout. Niceritorol decreased the serum concentrations of Lp(a) in gout. CONCLUSIONS: These observations suggest that serum Lp(a) concentrations are increased in patients with gout and may play a role as one of the risk factors for atherosclerotic diseases in gout. Niceritorol seems effective in decreasing high levels of Lp(a) in patients with gout without detrimental influence on serum uric acid concentration.

Adult↗
PubMed1995

Apolipoprotein E phenotypes in patients with gout: relation with hypertriglyceridaemia.

OBJECTIVE: To elucidate the relationship, if any, between lipid abnormalities and apolipoprotein E (apo E) polymorphism, by investigating apo E phenotype and allele frequency. METHODS: Fasting blood samples were taken for determination of apo E phenotype and serum lipids in 221 male patients with gout and 141 control male subjects. Apo E phenotype was determined by one dimensional flat gel isoelectric focusing. RESULTS: Frequencies of apo E phenotypes in gout were apo E3/3 67.9%, E4/3 18.1%, E4/4 2.3%, E4/2 1.8%, E3/2 9.5%, and E2/2 0.5%; those in control male subjects were 74.5%, 15.6%, 0%, 1.4%, 7.1%, and 1.4%, respectively. Frequencies of the e2, e3, and e4 alleles in gout were 0.061, 0.817 and 0.122, compared with the corresponding control frequencies of 0.057, 0.858 and 0.085. These differences in apo E phenotype and allele frequencies between gout and control subjects were not significant. The frequency of apo e4 allele in hyperlipidaemic gout subjects was significantly greater than that in normolipidaemic gout subjects; in contrast, its frequency was not different between hyperlipidaemic and normolipidaemic control subjects. Serum triglyceride, total cholesterol, apo B and E concentrations were significantly greater in gouty patients with the apo E4/3 phenotype than in those with gout having the apo E3/3 phenotype. CONCLUSIONS: These data suggest that gout subjects with hyperlipidaemia (hypertriglyceridaemia, hypercholesterolaemia or both) possess the apo e4 allele with higher frequency than those with normolipidaemia. They also suggest that apo e4 may induce some susceptibility to the development of hyperlipidaemia in gout in addition to that induced by obesity or excessive alcohol consumption, and may contribute to the high prevalence of atherosclerotic diseases in gout patients.

Alleles↗
PubMed1995

Effect of glucose infusion on the renal transport of purine bases and oxypurinol.

The effect of glucose infusion on renal handling of purine bases and oxypurinol was examined in 6 normal subjects. Five hundred milliliters of 1.1 M glucose solution were administered intravenously in 1 h. Fractional clearances of uric acid, xanthine and oxypurinol were significantly increased during glucose infusion, but that of hypoxanthine was not changed, while a 1-hour infusion of 500 ml of 1.1 M mannitol had no effect on the fractional clearances of purine bases and oxypurinol. These data indicate that the effect of glucose infusion on the renal clearances of uric acid, xanthine and oxypurinol was not related to osmotic diuresis but induced by glycosuria and/or hyperglycemia. Accordingly, the glycosuria- and/or hyperglycemia-induced decrease in the biological half-life of oxypurinol must be considered in the administration of allopurinol to gouty patients with uncontrolled diabetes mellitus.

Adult↗
PubMed1995

Elevated serum hepatocyte growth factor/scatter factor levels in inflammatory lung disease.

Hepatocyte growth factor/scatter factor (HGF/SF) plays an important role in tissue repair in liver and renal damage. The clinical significance of this growth factor in these diseases has also been reported. The lung is one of the major sources of HGF/SF; because of this, we investigated serum HGF/SF levels in 26 patients with inflammatory lung disease (15 with interstitial pneumonitis [IP], 11 with bacterial pneumonia [BP]) by enzyme-linked immunosorbent assay. As controls, we measured HGF/SF in the serum of 13 stable outpatients with chronic respiratory failure. All patients had no significant liver or renal dysfunction. Serum HGF/SF levels were significantly elevated in patients with IP (1.16 +/- 0.22 ng/ml) or BP (0.96 +/- 0.27 ng/ml) compared with those in the control subjects (0.29 +/- 0.03 ng/ml, both p < 0.01). Serum HGF/SF levels in 14 healthy subjects were also studied, and the results (0.30 +/- 0.02 ng/ml) were not remarkably different from those of the control subjects. There were no significant correlations between serum HGF/SF levels and C-reactive protein and lactate dehydrogenase. Serum HGF/SF levels in the surviving patients rapidly decreased with treatment, but they did not change in the patients who ultimately died. Our results demonstrate the clinical significance of serum HGF/SF level as a useful indicator of prognosis in inflammatory lung disease.

Adolescent↗
PubMed1995

Relation between markers for viral hepatitis and clinical features of Japanese patients with hepatocellular carcinoma: possible role of alcohol in promoting carcinogenesis.

To assess the relationship between hepatitis virus markers and the clinical features of hepatocellular carcinoma (HCC), we measured markers for hepatitis B virus (HBV) and hepatitis C virus (HCV) in 88 Japanese patients with HCC. Twelve (14%) patients were HBsAg-positive and 67 (76%) were anti-HCV-positive (both c100-3 and c11/c7). HCV-RNA was detected in 8 (38%) of the 21 anti-HCV-negative patients by PCR, so that 75 patients (85%) were infected with HCV. Of the HBsAg-negative patients infected with HCV with no history of blood transfusion, the mean age of the alcoholics (consumption > 80 g ethanol daily for at least 10 years) was lower than that of the non-alcoholics (60 years vs. 65 years, P < 0.05). Among the HBsAg-negative and anti-HCV (or HCV-RNA)-positive patients with a history of blood transfusion, the mean interval between the time of blood transfusion and the diagnosis of HCC in the alcoholics was shorter (21 years) than that in the nonalcoholics (27 years), but the difference was not statistically significant. We conclude that infection by both HCV and HBV may play a role in the development of HCC, and that alcohol consumption may promote carcinogenesis.

Adult↗
PubMed1995

Xylitol-induced increase in the concentration of oxypurines and its mechanism.

We investigated the effect of xylitol on the plasma concentration and the urinary excretion of purine bases, 5-hydroxypyrazinamide and 5-hydroxypyrazinoic acid in subjects who had ingested pyrazinamide (60 mg/kg weight). One liter of 10% xylitol was infused intravenously over 2 hours to 5 subjects to whom pyrazinamide had been administered 10 hours before. Xylitol increased the plasma concentration of uric acid, hypoxanthine and xanthine, the urinary excretion of hypoxanthine and a ratio of lactic acid/pyruvic acid in blood, while it decreased the plasma concentration and the urinary excretion of inorganic phosphate, 5-hydroxypyrazinamide and 5-hydroxypyrazinoic acid. These results suggested that in addition to an increase in purine degradation by xylitol, xylitol-induced increase in the cytosolic NADH inhibited xanthine dehydrogenase activity in the liver and the small intestine.

Administration, Oral↗
PubMed1995

[Alcohol-induced hypertriglyceridemia in subjects with decreased lipoprotein lipase--improvement after cessation of alcohol intake].

We systematically investigated the effect of lipoprotein lipase (LPL) and alcohol intake on the development of primary type IV hyperlipoproteinemia which is manifested as a moderate increase in serum triglycerides as a consequence of an elevated very low density lipoprotein concentration and a normal level of serum cholesterol. Twenty six type IV hyperlipoproteinemic and 28 normolipidemic males underwent measurement of the immunoreactive LPL mass in postheparin plasma (30 unit of heparin/kg of body weight) and were interviewed as to their alcohol consumption. They were divided into 4 groups, with a LPL mass of 150ng/ml (20 percentile of the normal range) and an alcohol intake of 33g/day as the borderlines. All subjects with LPL mass less than 150ng/ml and alcohol intake of more than 33g/day were prone to manifest type IV hyperlipoproteinemia. One of the subjects in this group showed a recovery to normolipidemic state after cessation of alcohol intake. Subject whose LPL mass value was more than 180ng/ml (50 percentile of the normal range) were not susceptible to type IV hyperlipoproteinemia even though they drank alcohol more than 33g/day.

Alcohol Drinking↗
PubMed1994

The histidine interruption of an alpha-helical coiled coil allosterically mediates a pH-dependent ligand dissociation from macrophage scavenger receptors.

Macrophage scavenger receptors uptake modified low density lipoproteins (LDLs) through receptor-mediated endocytosis. In the alpha-helical coiled coil domain, 2 histidines (His168 and His260) disrupt leucine or isoleucine heptad repeats. Substitution of His168 or/and His260 to leucine had no effect on AcLDL binding activities. However, the His260-replaced receptors had their ligand degradation activities diminished. Cell surface ligand release experiments under acidic pH clarified that His260 mutants lost their ligand dissociation activities at 37 degrees C. Furthermore, immunoelectron microscopic experiments using anti-scavenger receptor antibody showed that the His260 replaced receptors were not able to release gold-labeled AcLDL in endosomes. Here we propose an allosterical ligand dissociation mechanism by His260 in macrophage scavenger receptors.

Allosteric Regulation↗
PubMed1994

Structural comparison of phospholipase-A2-binding regions in phospholipase-A2 receptors from various mammals.

We determined the nucleotide sequence of a mouse cDNA encoding the receptor for pancreatic group I phospholipase A2 (PLA2-I). Interspecies structural comparison of the mouse receptor with bovine PLA2-I receptor, whose structure had been clarified, revealed that the fourth carbohydrate-recognition domain (CRD)-like domain (CRD-like 4) was the most conserved among the domains in the PLA2-I receptor, suggesting the functional importance of CRD-like 4. A transient expression experiment with a truncated form of the receptor consisting of three CRD-like domains, from the third to the fifth, demonstrated that the PLA2-I-binding site of the receptor is constituted from these three CRD-like domains, supporting the functional indispensability of CRD-like 4 in the receptor. Since the PLA2-I-binding region was thus assigned to be CRD-like domains 3-5, we further analyzed the structures of the PLA2-I-binding regions in the PLA2-I receptors from the rat, rabbit and human. Furthermore, the obtained PLA2-I receptor cDNA fragments from these animals made it possible to examine the tissue expression patterns of this receptor in various mammals. The results, together with the results of the genomic structural analysis of this gene, indicated that a PLA2 receptor recently characterized by Lambeau et al. [Lambeau, G., Ancian, P., Barhanin, J. & Lazdunski, M. (1994) J. Biol. Chem. 269, 1575-1578] is a rabbit counterpart of the PLA2-I receptor although these two PLA2 receptors have distinctive PLA2-binding specificities.

Amino Acid Sequence↗
PubMed1994

Identification and characterization of IL-2 hyper-responsive NZB/WF1 CD5- B cells.

The responsiveness of CD5- and CD5+ B cells of BALB/c and NZB/WF1 mice to various cytokines was examined with respect to their growth and differentiation. BALB/c splenic CD5- B cells required longer incubation with IL-2 or pretreatment with IL-4 to respond to IL-2 by DNA synthesis, whereas NZB/WF1 CD5- B cells were highly competent to IL-2. Flow cytometric analysis demonstrated that NZB/WF1 and BALB/c CD5- B cells had higher and intermediate proportions of B cells positive for IL-2R beta, respectively. On the other hand, BALB/c and NZB/WF1 splenic CD5+ B cells consisted of lower proportion of B cells positive for IL-2R beta than did their corresponding CD5- B cells and grew meagerly in response to IL-2. Peritoneal exudative CD5+ B cells of NZB/WF1 mice lacked IL-2R beta mRNA expression and failed to respond to IL-2. Although both BALB/c and NZB/WF1 CD5- B cells pretreated with anti-IgM, IL-4, and IL-5 responded to IL-2 by DNA synthesis, only BALB/c CD5- B cells developed into IgM-producing cells. Furthermore, BALB/c, but not NZB/WF1 CD5-, B cells pretreated with anti-IgM and IL-5 responded to IL-2 by IgM production without DNA synthesis. Thus, cross-talk between IL-4 and IL-2 operated in the growth responses of both BALB/c and NZB/WF1 splenic CD5- B cells, whereas cross-talk between IL-5 and IL-2 operated only in the differentiation of BALB/c CD5- B cells, providing us with another intriguing functional abnormality of NZB/WF1 B cells.

Animals↗
PubMed1994

Molecular cloning of pancreatic group I phospholipase A2 receptor.

We have recently reported that mammalian pancreatic group I phospholipase A2 (PLA2-I) has its specific receptor (PLA2 receptor) on a variety of mammalian cells and that various biological responses are elicited by PLA2-I via this receptor. In this study, we cloned cDNAs encoding a protein corresponding to the bovine PLA2 receptor purified from the corpora lutea on the basis of its partial amino acid sequences. The identity of a protein encoded by the cloned cDNA with the bovine PLA2 receptor was verified by a transient expression experiment using COS-7 cells. Interestingly, the deduced primary structure of the PLA2 receptor (1,463 amino acid residues) exhibits a close relatedness throughout the molecule to that of the macrophage mannose receptor, a unique member of Ca(2+)-dependent (C-type) animal lectin family, in spite of their functional diversity. Based on this sequence similarity between these two receptors, the domain organization of the PLA2 receptor could be tentatively assigned as follows; 10 extracellular domains including 8 tandem repeats homologous to C-type carbohydrate-recognition domains (CRDs) and a single transmembrane region followed by a short cytoplasmic tail. The results of transient expression experiments for mutant PLA2 receptors supported this assignment and furthermore suggested the region responsible for PLA2-I binding corresponds to CRDs in the mannose receptor.

Amino Acid Sequence↗