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M Shimatani

Publications and source records attributed to M Shimatani.

9 recordsLinked to original sources
PubMed2000

A method for measuring specific IgE in sera by direct ELISA without interference by IgG competition or IgG autoantibodies to IgE.

BACKGROUND: In measuring specific IgE levels in sera by direct ELISA, competition with coexisting IgG often impedes an exact IgE determination; additionally, IgG autoantibodies to IgE (IgG-IgE) in sera affect the assay. In this paper, we attempt to determine accurate specific IgE levels by selective removal of IgG with a protein G-immobilized gel (PG) and by acid treatment of the PG to compensate for the unintended removal of IgE, probably due to the PG binding IgG-IgE. METHODS: IgG in sera was removed using PG at pH 7.0. Then, the PG was treated with citrate buffer at pH 3.0 for 5 min to liberate IgE from IgG-IgE complexes, after IgG-binding sites on the PG were saturated with bovine IgG, since PG came to bind IgE at acidic pHs. IgE levels were then measured by ELISA. RESULTS: The PG treatment of sera removed the effect of inhibitory competition by coexisting IgG, especially at higher concentrations of sera, to improve specific IgE detection by direct ELISA. However, PG treatment alone sometimes reduced IgE levels (39% of sera tested), even though PG does not bind IgE at pH 7.0, which indicated the presence of IgG-IgE complexes. The reduction in IgE returned almost to their original levels in the sera by acid treatment of the PG. By combining the PG treatment with acid treatment, specific IgE measurement in sera was improved significantly (p < 0.01, Wilcoxon signed rank test). CONCLUSION: Measurement of specific IgE in sera by direct ELISA was improved by using the PG and acid treatment technique.

Animals↗
PubMed1982

Blood and tissue levels of lipoperoxides in rats during development.

The excessive accumulation of lipoperoxides has been accepted as being highly responsible for the development of retinopathy of prematurity and idiopathic respiratory distress syndrome of the newborn infant. We have studied development-related levels of lipoperoxides in blood and tissues such as the liver, lungs, kidneys and brain from birth to adult age using rats as the experimental animal. Lipoperoxide concentrations in blood and tissues were low in fetal and early newborn periods. The concentrations increased with age and peaked in the early newborn period and gradually decreased as the development progressed. In vitro lipoperoxide formation and accumulation in tissues exhibited a close correlation with in vivo lipoperoxide concentrations, except in the brain.

Aging↗
PubMed1982

Lipid peroxidation and antioxidants in rat liver during development.

The concentration of lipid peroxidation was extensively high in rat fetuses and early newborns. However, it declined sharply thereafter. Superoxide dismutase (SOD) activity was approximately 10% of the adult level during 5 days postpartum. The enzyme activity began to increase after the 10th day to 60% of the adult level at the 20th day. Catalase activity was low in the fetal period, corresponding to approximately 20% of the adult level, but increased rapidly after birth reaching approximately 50% of the adult level at 5-7 days postpartum. Glutathione peroxidase (GSH-Px) activity was measured to amount to only 7% of the adult level in the fetal and early newborn period. The level of this activity was approximately 20% of the adult level at the 20th day. The difference in GSH-Px activity became wide between sexes after the first 30 days of life; the male adult level was 61% of the female adult level. The concentration of vitamin E was low in the fetus. It increased by a factor of 10 times within a few days after birth, and thereafter it decreased gradually. Fetal and early newborn livers have low enzymatic defense capabilities against possible deleterious effects of lipid peroxidation processes.

Aging↗
PubMed1979

Prevention of penicillin-induced lysis of Staphylococcus aureus by cellular lipoteichoic acid.

The lysis of Staphylococcus aureus FDA 209P induced by benzylpenicillin was completely inhibited by cellular lipoteichoic acid isolated from an homologous organism. The cells prevented from penicillin-induced lysis were in static state and did not lose viability. The lipoteichoic acid inhibited either extracellular autolysin activity in culture supernatant or autolysis of whole cells in exponential phase of S. aureus. These results indicate that the prevention of penicillin-induced lysis of S. aureus by the lipoteichoic acid was brought about by the inhibition of autolytic activity of the organism.

Bacteriolysis↗
PubMedDate not supplied

Human neutrophil functions in obstructive jaundice.

BACKGROUND/AIMS: The effect of obstructive jaundice on neutrophil function has not been extensively studied. Therefore, the present study aimed at evaluating the effect of obstructive jaundice on human neutrophils. METHODOLOGY: Twelve patients with obstructive jaundice due to common bile duct obstruction underwent endoscopic biliary drainage. Neutrophil functions (chemotaxis and superoxide anion generation) were evaluated before and 7 days after drainage. RESULTS: Neutrophil chemotaxis in response to FMLP (formyl-methionyl-leucyl-phenylalanine) or interleukin-8 was abnormally increased before drainage, and was normalized after drainage. Similarly, enhanced superoxide anion generation in response to FMLP or phorbol myristate acetate before drainage was alleviated after drainage. CONCLUSIONS: The results suggest neutrophil overactivity in patients with obstructive jaundice. The ameliorating effect of biliary drainage on neutrophil overactivity might play a role in the prevention of postoperative complications.

Adult↗