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Biomedical subjects

K Hirano

Publications and source records attributed to K Hirano.

At least 19 recordsLinked to original sources
PubMed1992

Monoclonal antibodies against human alpha-fetoprotein more reactive to cell-surface alpha-fetoprotein than to free alpha-fetoprotein.

This paper describes the finding of monoclonal antibody (MoAb) more reactive to cell-surface alpha-fetoprotein (AFP) than to free AFP by using a simple in vitro system. Twelve mouse MoAbs, ten IgG1, one IgG2a and one IgG2b, against human AFP from hepatocellular carcinoma were obtained by the cell fusion technique. Each hybridoma supernatant was assayed by enzyme-linked immunosorbent assay (ELISA) to solid-phase AFP. The assay results showed that two MoAbs, 67D and 80G, were most reactive to AFP. 80G had a higher affinity constant than 67D, while the both reactions were similarly difficult to inhibit by free AFP in ELISA. 67D and 80G reacted with AFP on the surface of ethanol-fixed cells from the human hepatoma cell line HuH-7 and this reaction was also difficult to inhibit by free AFP in Cell ELISA. Furthermore, Western blot analysis showed that 67D and 80G were more reactive to membrane-bound AFP than other antibodies. These findings first suggest that there could be anti-AFP MoAbs preferably binding to cell-surface AFP rather than to serum AFP.

Antibodies, Monoclonal↗
PubMed1992

Etiological implication of autoantibodies to zona pellucida in human female infertility.

PROBLEM: Autoantibodies to zona pellucida (ZP) have been implicated as a cause of infertility in woman by three lines of clinical and laboratory evidence. METHOD: First, positive anti-zona activities, as assessed by the passive hemagglutination reaction (PHAR) using bovine red blood cells sensitized with porcine zona antigen, were detected in 45 of 1,872 serum samples collected from infertile women, but in only three (two nonpregnant and one pregnant) of 592 serum samples from control subjects. Their incidence in 320 women with unexplained infertility (5.6%) was much higher than that in 1,552 women with infertility of known cause (1.7%, P < 0.01), which was comparable to the incidence observed in 193 age-matched fertile nonpregnant and pregnant women (1.5%, P < 0.05). None of the serum samples from 292 age-matched adult men and 100 children of between 5 and 10 years old gave a positive PHAR. Second, follow-up study for a minimum of 2 years with treatment revealed that no pregnancy occurred in 11 infertile women with a consistently positive PHAR, and only three pregnancies in 19 infertile women with a fluctuating positive PHAR. Third, three of seven serum samples from women who gave a consistently positive PHAR produced strong immunofluorescence reactions on human ZP even after adsorption with porcine and human AB blood cells. Pre-exposure of human ZP to the sera showing positive immunofluorescence, including that of one patient undergoing an in vitro fertilization program, greatly diminished the number of spermatozoa of normal quality that bound to and penetrated across human ZP. CONCLUSIONS: The observed high incidence of anti-zona activities and long-term resistancy to treatment in women with unexplained infertility may be closely correlated with inhibition of sperm-egg interaction by anti-zona autoantibodies produced in these women.

Antibody Formation↗
PubMed1992

Assembly of 100 nm periodic fibrils (type VI collagen) in human infant corneal stroma.

An experimental model for the age-related changes in the extracellular matrix of the human cornea was developed. Human infant corneal stroma in which no long-spacing collagen occurred naturally was treated with 20 mM adenosine triphosphate (ATP). The ATP-treated cornea was observed and compared with nontreated control specimens by electron microscopy. Numerous 100 nm periodic fibrils which resembled long-spacing collagen were formed by the treatment. These experimentally formed fibrils appeared to attract and aggregate the collagen fibrils with D-periodicity, which indicated a connection between type VI and type I collagen. By ruthenium red staining, the cross-bands of the 100 nm periodic fibrils were positively stained, indicating that glycosaminoglycans or proteoglycans were involved in the formation of these fibrils.

Adenosine Triphosphate↗
PubMed1992

[A case report of chronic tubulo-interstitial nephritis].

We report a case of 10-year-old boy with chronic tubulo-interstitial nephritis (TIN). He had febrile convulsion and received sodium valproate (VPA) treatment. 18 months later, he had developed Fanconi syndrome. On admission, he also had evidence of tubular and glomerular dysfunction. Renal biopsy revealed interstitial nephritis with linear tubular-basement-membrane deposition of IgG and C3 and dominant infiltration of CD4 positive cells in interstitium. Although there is not a positive proof of the etiology in the relationship between TIN and VPA, it is likely that VPA is a possible cause of chronic TIN from his past history.

CD4 Antigens↗
PubMed1978

An enzymic determination for serum phospholipid.

A new colorimetric determination for serum phospholipid is described. Firstly, serum phospholipid is incubated with phospholipase C from Bacillus cereus, and then the released diglyceride and triglyceride are hydrolyzed completely to fatty acid and glycerol by lipoprotein lipase from Pseudomonas fluorescens. Secondly, the glycerol produced is enzymatically determined by glycerol dehydrogenase in the presence of NAD+, using phenazine methosulfate-nitro blue tetrazolium as color reagents. The absorbance at 570 nm is recorded. The amount of the glycerol from phospholipid is calculated by subtracting the amount of glycerol from triglyceride from the amount of total glycerol. The present method requires only 20 microliter of serum and a 40 min incubation and is highly reproducible. The results obtained show good correlation with those obtained by a chemical method (correlation coefficient, 0.925) or the phospholipase D-choline oxidase method (correlation coefficient, 0.936). These results strongly suggest that the proposed method can be utilized as a routine clinical test.

Glycerol↗
PubMed1978

Human fetal organ alkaline phosphatases.

The properties of human fetal alkaline phosphatase (ALP) have been compared with those of purified human adult hepatic and intestinal ALPs. The ALPs from different human fetal organs were divided into two groups. One terminated universal type was presented in fetal liver, spleen, adrenal, kidney, lung, heart, pancreas, thymus and bone, and was similar to adult hepatic-type ALP. The other terminated intestinal type was presented in fetal intestine and meconium and was similar to adult intestinal ALP. The activity of human fetal intestinal ALP increased markedly with the advance of intra-uterine life during fetal development, and that of human fetal thymus ALP increased slightly.

Adult↗
PubMed1977

DNA repair enzymes in ataxia telangiectasia and Bloom's syndrome fibroblasts.

Ataxia telangiectasia, Bloom's syndrome and normal fibroblasts were compared as to the capacity of their cellular extracts to enhance the priming activity of gamma-irradiated colicin E1 DNA for purified DNA polymerase. It was found that an ataxia strain had substantially lower, and a Bloom's syndrome strain had slightly lower capacity than a normal strain; while the activities of apurinic site specific endonuclease in these extracts were comparable.

Ataxia Telangiectasia↗
PubMed1977

A simple colorimetric method for determination of serum triglycerides with lipoprotein lipase and glycerol dehydrogenase.

A simplified enzymic procedure to determine accurately serum triglycerides is described. Serum triglycerides are hydrolyzed completely to free fatty acids and glycerol by lipoprotein lipase from Pseudomonas fluorescens. The released glycerol is oxidized with glycerol dehydrogenase from Erwinia aroideae in the presence of NAD+, were the reduction of the enzyme-linked NAD+ is coupled to the reduction of nitro blue tetrazolium as a chromogenic indicator with phenazine methosulfate serving as an intermediate electron carrier of NADH. The absorbance at 570 nm is measured. The method requies only 20 microliter of serum and a 10-min incubation and is rapid and simple. The present method offers the measurement of a high concentration of triglyceride up to 1000 mg/dl serum. The results obtained by the present method show good correlation with those obtained by the glycerol kinase method (correlation coefficient, 0.989) or the acetylacetone method (correlation coefficient, 0.979). These results suggest that the proposed method will be utilized as a method or routine clinical test.

Colorimetry↗
PubMed1977

Purification, crystallization and properties of triacylglycerol lipase from Pseudomonas fluorescens.

Triacylglycerol lipase of Pseudomonas fluorescens was purified from the crude enzyme by ammonium sulfate precipitation and chromatographies on Sephadex G-75 and DEAE-cellulose. The crystallization of the lipase was successfully carried out. The purified lipase was demonstrated to be homogenous on disc electrophoresis and its molecular weight was calculated to be 32 000 by gel filtration. The optimum pH for hydrolysis of sesame oil was 7.0. The enzyme was stable up to 40 degrees C under the condition of pH 7.0 for 30 min and had more than 80% of the remaining activity between pH 5.0--11.0 at 37 degrees C for 60 min. The lipase was strongly inhibited by iodine and partially inhibited by FeCl3 and N-bromosuccinimide, and showed the most activity on tricaproyglycerol, among the triacylglycerols used.

Crystallization↗
PubMed1977

A new method for peptidase activity measurement in serum and tissues, using L-Leu-L-Leu as substrate.

Peptidase-free L-amino-acid oxidase was purified from venom of Agkistrodon caliginosus and was used for the determination of serum peptidase (EC 3.4.1.-) activity with L-Leu-L-Leu as substrate. The peptidase activity in human serum rose remarkably in liver diseases, and had a significant correlation with serum transaminase activity. The peptidase activity in serum of rats treated with CCl4 was higher than that of normal rats. After Cellogel electrophoresis the zymogram of peptidase from human liver using di- or tripeptide as substrate appeared with three active bands; however, peptidase in serum of a patient with acute hepatitis showed only one active band.

Adult↗
PubMed1977

Purification and properties of human liver peptidase.

The peptidase from human liver was purified using L-Leu-L-Leu as a substrate, in adapted purification techniques including treatment with n-butanol, acetone precipitation, ammonium sulfate fractionation, DEAE-cellulose chromatography, Sephadex G-150 gel filtration and CM-cellulose chromatography. The purified enzyme exhibited homogeneity in disc electrophoresis. The molecular weight of the enzyme was estimated to be 130 000 by Sephadex G-200 gel filtration. The isoelectric point of the enzyme was found to be pH 5.6. The enzyme was activated by Mn2+ and inhibited by o-phenanthroline. L-Leu-L-Leu and L-Phe were hydrolyzed effectively by the peptidase. By electrophoresis on Cellogel, the electrophoretic mobility of purified enzyme was same as that of the peptidase in serum of patients with hepatic disease.

Cations, Divalent↗