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Biomedical subjects

T Miwatani

Publications and source records attributed to T Miwatani.

At least 199 records · Page 11Linked to original sources
PubMed1976

Isolation of a factor causing morphological changes of chinese hamster ovary cells from the culture filtrate of Vibrio parahaemolyticus.

A factor changing Chinese hamster ovary cells from an oval to a spindle shape was isolated from the culture filtrate of Vibrio parahaemolyticus. It was partially purified by successive column chromatographies on diethylaminoethylcellulose, diethylaminoethyl-Sephadex A-25, hydroxylapatite, and Sephadex G-200. This factor was separated from thermostabl direct hemolysin and was heat labile.

Animals↗
PubMed1975

Characterization of the temperature-dependent inactivating factor of the thermostable direct hemolysin in Vibrio parahaemolyticus.

The termostable direct hemolysin of Vibrio parahaemolyticus is inactivated by heating at around 55 C with an inactivating factor isolated from culture filtrates of V. parahaemolyticus. The characteristics of the temperature-dependent inactivating factor were studied by using polyacrylamide gel disc electrophoresis. It was found that when heated with the hemolysin, the inactivating factor destroyed the hemolysin and thus inactivated the hemolytic activity, suggesting that the inactivating factor has proteolytic activity. It was also demonstrated that the inactivating factor itself is heat labile, losing its activity on heating with the hemolysin at 95 C for 15 min. The inactivating factor was stimulated by the presence of NaCl or MgCl2 and showed maximal activity at around pH 8.0. The results support our previous hypothesis that the Arrhenius effect observed with crude hemolysin of V. parahaemolyticus is due to the presence of a temperature-dependent inactivating factor. The fact that the factor is activated on heating at 50 to 60 C but is inactivated on heating at 70 to 100 C explains the Arrheius effect of crude hemolysin of V. parahaemolyticus.

Cell-Free System↗
PubMed1975

Interaction of thermostable direct hemolysin of Vibrio parahaemolyticus with human erythrocytes.

The interaction between thermostable direct hemolysin produced by Vibrio parahaemolyticus WP-1 and human erythrocytes was studied. The lysis of human erythrocytes by the hemolysin was dependent of temperature and no hemolysis occurred at low temperature (0-4 C), but the hemolysin was adsorbed on human erythrocytes even at low temperature. No hemolysis was observed when antihemolysin antiserum was mixed with the hemolysin and human erythrocytes at zero time. On the other hand, lysis of the cells by hemolysin was not completely inhibited when the antiserum was added during the lag time and the inhibitory effect decreased with delay in the time of addition of antiserum. The inhibitory effect of the antiserum decreased with increase in the incubation temperature, increase in the concentration of divalent cations, and decrease in pH. These results suggest that lysis of human erythrocytes by the hemolysin is at least a two-step process consisting of adsorption of the hemolysin to human erythrocytes and the step(s) following adsorption.

Adsorption↗
PubMed1974

Demonstration of a temperature-dependent inactivating factor of the thermostable direct hemolysin in Vibrio parahaemolyticus.

A factor was found in Vibrio parahaemolyticus which inactivated the hemolytic activity of a purified, thermostable direct hemolysin. The inactivating factor was associated with the hemolysin but could be separated from it by diethylaminoethyl-cellulose column chromatography. The inactivating factor was activated by heating at 50 to 60 C, but was itself thermolabile and lost activity on heating to 70 to 100 C. The mechanism of the Arrhenius effect, observed with crude hemolysin of V. parahaemolyticus, is as follows. At 50 to 60 C, the temperature-dependent inactivating factor associated with hemolysin inactivates the hemolysin, whereas at 80 to 100 C the crude hemolysin retains activity because at this temperature the factor is inactivated.

Ammonium Sulfate↗
PubMed1974

Existence of two distinct hemolysins in Vibrio parahaemolyticus.

Two distinct hemolysins were demonstrated in Vibrio parahaemolyticus. A thermostable direct hemolysin purified from V. parahemolyticus WP-1, a Kanagawa phenomenon (KP)-positive strain, is antigenically different from a thermolabile hemolysin produced by V. parahaemolyticus T-3454, a KP-negative strain. The thermostable direct hemolysin was found in KP-positive strains but not in KP-negative strains. On the other hand, the thermolabile hemolysins were found in both KP-positive and -negative strains, although some KP-positive strains did not produce this hemolysin.

Animals↗
PubMed1974

Antigenic difference between polar montrichous and peritrichous flagella of Vibrio parahaemolyticus.

Polar monotrichous and peritrichous flagella of Vibrio parahaemolyticus were isolated and purified separately. On hydroxylapatite column chromatography, the flagellins of polar monotrichous flagella were eluted with a higher concentration of phosphate than those of peritrichous flagella. Gel diffusion tests showed an antigenic difference between the flagellins of polar monotrichous and peritrichous flagella. Electron microscope observations on cells stained with ferritin-conjugated antibodies demonstrated that polar monotrichous and peritrichous flagella reacted specifically with antimonotrichous flagellin and antiperitrichous flagellin antisera, respectively.

Animals↗