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M Yoh

Publications and source records attributed to M Yoh.

At least 55 records · Page 3Linked to original sources
PubMed1990

Properties of a hemolysin related to the thermostable direct hemolysin produced by a Kanagawa phenomenon negative, clinical isolate of Vibrio parahaemolyticus.

A hemolytic toxin (Vp-TRH) produced by a Kanagawa phenomenon negative, clinical isolate of Vibrio parahaemolyticus was further characterized. The purified Vp-TRH showed various biological activities, such as fluid accumulation in rabbit ileal loops, increase of rabbit skin vascular permeability, and cardiotoxicity on cultured myocardial cells, all of which are essentially similar to the activities found with thermostable direct hemolysin (Vp-TDH), a pathogenic toxin produced by Kanagawa phenomenon positive V. parahaemolyticus. Immunological similarities of Vp-TRH not only to Vp-TDH but also to hemolytic toxins produced by Vibrio hollisae and Vibrio cholerae non-O1, both of which are also enteropathogens closely related to V. parahaemolyticus, were demonstrated. The amino acid composition and sequence of N-terminal amino acids of Vp-TRH were determined. These results suggest that Vp-TRH has biological and immunological characters similar to Vp-TDH, although they are distinct molecules.

Amino Acid Sequence↗
PubMed1989

Homogeneity of a hemolysin(Vh-rTDH) produced by clinical and environmental isolates of Vibrio hollisae.

The characteristics of Vh-rTDH, a hemolysin similar to Vp-TDH of Vibrio parahaemolyticus produced by clinical and environmental isolates of Vibrio hollisae, were comparatively studied. All 7 strains of V. hollisae tested were found to produce indistinguishable Vh-rTDH when they were examined by heat-stability test, Western blotting analysis and conventional polyacrylamide slab gel electrophoresis.

Animals↗
PubMed1989

Production of monoclonal antibodies against thermostable direct hemolysin of Vibrio parahaemolyticus and application of the antibodies for enzyme-linked immunosorbent assay.

A total nine hybridoma cell lines that produced monoclonal antibodies against thermostable direct hemolysin (Vp-TDH), a possible pathogenic toxin, of Kanagawa phenomenon-positive Vibrio parahaemolyticus was isolated and characterized. These monoclonal antibodies (mAbs) were divided into a minimum of five different specificity groups, including mAbs specific to Vp-TDH and common to Vp-TDH and Vp-TRH, a Vp-TDH-related hemolysin produced by Kanagawa phenomenon-negative V. parahaemolyticus. An enzyme-linked immunosorbent assay (ELISA) using mAb-1-D, a mAb specific for Vp-TDH, was developed for specific detection of Vp-TDH. On the other hand, the ELISA using mAb-9-D, and mAb common to both Vp-TDH and Vp-TRH, could be used for detection of both Vp-TDH and Vp-TRH. Thus, by combining these two ELISAs differential detection of Vp-TDH and Vp-TRH can be performed. Hence, the two ELISAs were applied for various strains of V. parahaemolyticus and it was found that most Kanagawa phenomenon-positive and -negative clinical isolates produced Vp-TDH and Vp-TRH, respectively, but all environmental strains, that were Kanagawa phenomenon-negative, produced neither toxin.

Animals↗
PubMed1989

Comparative amino acid sequence analysis of hemolysins produced by Vibrio hollisae and Vibrio parahaemolyticus.

Vibrio hollisae produces a hemolysin (Vh-rTDH) that is related to the thermostable direct hemolysin of Vibrio parahaemolyticus (Vp-TDH). Although both hemolysins are essentially similar biologically and immunologically, they differ markedly in heat stability; Vp-TDH is heat stable, whereas Vh-rTDH is heat labile. To elucidate the relationships between their characteristics and molecular structures, we analyzed the amino acid sequence of Vh-rTDH and compared it with that of Vp-TDH. Vh-rTDH consisted of 165 residues, of which 23 residues, spread over the peptide chain, differed from those of Vp-TDH.

Amino Acid Sequence↗
PubMed1988

Isolation from a coastal fish of Vibrio hollisae capable of producing a hemolysin similar to the thermostable direct hemolysin of Vibrio parahaemolyticus.

A vibrio isolated from the intestine of a coastal fish was identified as Vibrio hollisae by its biochemical characteristics. The isolate reacted with the gene probe for the thermostable direct hemolysin of Vibrio parahaemolyticus. The hemolysin produced by the isolate from the fish had traits identical to those of the thermostable direct hemolysin-like hemolysin produced by a clinical strain of V. hollisae.

Animals↗
PubMed1988

Comparison of hemolysins of Vibrio cholerae non-O1 and Vibrio hollisae with thermostable direct hemolysin of Vibrio parahaemolyticus.

Hemolysin (Vh-rTDH) produced by Vibrio hollisae and hemolysin (NAG-rTDH) produced by Vibrio cholerae non-O1 were characterized and compared with hemolysin (Vp-TDH) produced by Vibrio parahaemolyticus. These three hemolysins are each composed of two subunits and have similar, but not identical, molecular weights. The amino acid compositions of Vp-TDH and NAG-rTDH are similar, but are different from that of Vh-rTDH. The three hemolysins showed similar lethal toxicities to mice. The effects of temperature on hemolysis and the time dependencies of hemolysis by the three hemolysins were similar. The three were concluded to be immunologically related, but not identical, and to have common and also unique antigenic determinants.

Amino Acids↗
PubMed1987

[Quantitative evaluation of regional myocardial blood flow by digital subtraction angiography: correlations with exercise electrocardiography and Tl-201 myocardial scintigraphy].

We previously reported that the contrast disappearance half-life (T1/2) derived by the computerized washout analysis of digital subtraction coronary arteriograms provides a useful index for quantitatively evaluating regional myocardial blood flow. In the present study, we further evaluated the clinical usefulness of T1/2, comparing it with exercise electrocardiography and exercise thallium-201 myocardial scintigraphy. The study subjects consisted of 25 patients with angina pectoris and 14 patients with normal coronary arteries. Following the manual injection of contrast media into the left anterior descending coronary artery (LAD), a time-density curve was generated in the sectors of the myocardium which were perfused by the LAD and the T1/2 was calculated. T1/2 values correlated closely with double product (r = -0.73). They were significantly greater in patients with exercise-induced ST depression (8.3 +/- 1.0 vs 5.8 +/- 0.7, p less than 0.005). In addition, there was a good correlation between T1/2 values and washout ratio as determined by exercise thallium-201 myocardial scintigraphy, with r = -0.83. Although T1/2 values were within the normal range (mean +/- 2SD of control subjects) in all patients with LAD stenosis of 50 percent or less, these values were abnormally increased, exceeding the normal range, in 11 of the 12 patients with stenosis of 90 percent or more. Compared with exercise electrocardiography, T1/2 values were abnormally prolonged in 11 of the 13 patients with exercise-induced ST depression. Compared with exercise thallium-201 myocardial scintigraphy, T1/2 values were abnormally prolonged in seven of the nine patients with transient perfusion defects.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1987

[Videodensitometric assessment of right and left ventricular functions by digital subtraction angiography].

Right and left ventricular volumes and systolic indices were determined by intravenous digital subtraction ventriculography in 50 patients with various heart diseases. Using a constant injection speed of 35 ml Renografin-76 contrast medium, serial right and left ventriculograms were obtained in the 30 degree right anterior oblique projection. Right ventriculograms were also obtained in the 60 degree left anterior oblique projection. The videotape recordings of subtracted images were continuously digitized into 128 X 128 eight bit (256 gray scales) pixel matrices using an image-processing computer. The endocardial outlines of the right and left ventricles were drawn manually using a joystick, frame by frame, for each cardiac cycle. By integrating overall the pixel densitometric counts within this outline for each frame, the computer generated a time-density curve with maxima and minima represented in the end-diastolic and end-systolic frames, respectively. Systolic indices including ejection fraction (EF), one-third ejection fraction (1/3 EF) and the peak ejection rate (PER) were derived from the time-density curve. Right ventricular volume was determined by the single-plane or biplane mathematical formulae of Ferlinz et al., and left ventricular volume was calculated by the area-length method in the 30 degree right anterior oblique projection. Results by the two geometric methods correlated well for right ventricular volume (r = 0.84) and for EF (r = 0.80). Right ventricular densitometric counts correlated closely with single-plane volume (r = 0.91). Right ventricular ejection fraction (RVEF) determined by videodensitometry also correlated satisfactorily with that by single-plane angiography (r = 0.74).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Purification and partial characterization of a non-O1 Vibrio cholerae hemolysin that cross-reacts with thermostable direct hemolysin of Vibrio parahaemolyticus.

A newly identified hemolysin (NAG-rTDH), which is related to the thermostable direct hemolysin (Vp-TDH) of Vibrio parahaemolyticus produced by non-O1 Vibrio cholerae, was studied. NAG-rTDH was purified by successive column chromatographies on DEAE-cellulose and an immunoaffinity column coupled with anti-Vp-TDH immunoglobulin. The molecular weight of NAG-rTDH was estimated as 18,500, similar to that of Vp-TDH, as judged by sodium dodecyl sulfate slab gel electrophoresis, but its charge or molecular shape was different, judging from its electrophoretic mobility. The lytic activities of NAG-rTDH on erythrocytes of most animals were essentially similar to those of Vp-TDH, but that on sheep erythrocytes was different. The hemolytic activity of NAG-rTDH was stable on heating at 100 degrees C for 10 min, as was that of Vp-TDH. Immunological cross-reactivity between NAG-rTDH and Vp-TDH was demonstrated by both the Ouchterlony test and the neutralization test. Thus, we conclude that non-O1 V. cholerae produce a new type of hemolysin that is similar but not identical to the thermostable direct hemolysin of V. parahaemolyticus.

Cross Reactions↗
PubMed1986

Purification of the thermostable direct hemolysin of Vibrio parahaemolyticus by immunoaffinity column chromatography.

A simple method involving immunoaffinity column chromatography to purify the thermostable direct hemolysin of Vibrio parahaemolyticus was developed. The thermostable direct hemolysin purified from the culture supernatant of a strain isolated from the first reported case of V. parahaemolyticus infection in China in 1985 was indistinguishable from the hemolysins purified from strains isolated in Japan.

Chromatography, Affinity↗
PubMed1986

Purification and partial characterization of a Vibrio hollisae hemolysin that relates to the thermostable direct hemolysin of Vibrio parahaemolyticus.

Hemolysin produced by Vibrio hollisae (Vh-rTDH), which is related to the thermostable direct hemolysin (Vp-TDH) of Vibrio parahaemolyticus, was studied. Vh-rTDH was purified by successive column chromatographies on diethylaminoethyl-cellulose and an immunoaffinity column coupled with anti Vp-TDH immunoglobulin. The purified toxin was homogeneous, as demonstrated by conventional and sodium dodecyl sulfate--polyacrylamide gel electrophoresis (PAGE). The molecular weight of Vh-rTDH was slightly smaller than that of Vp-TDH, as determined by sodium dodecyl sulfate--slab gel electrophoresis. Conventional PAGE also showed a difference between Vh-rTDH and Vp-TDH. Vp-TDH and Vh-rTDH showed different lytic activities on erythrocytes from various animals, in particular chicken, sheep, and calf. The hemolytic activity of Vh-rTDH was heat labile when heated at 70 degrees C for 10 min, unlike Vp-TDH. Immunological cross-reactivity between Vh-rTDH and Vp-TDH was demonstrated by both the Ouchterlony test and neutralization test.

Animals↗
PubMed1985

A staphylococcal coagglutination test for detecting and serogrouping Legionella pneumophila.

For detection of Legionella pneumophila and determination of its serogroup, the modified staphylococcal coagglutination test was studied in detail. Cross-reactions in serum-agglutination tests were observed among serogroups, but immunoglobulin-coated staphylococcal cells could detect L. pneumophila with high sensitivity (a cell concentration with an absorbance of 0.008 at 660 nm could be detected) and serogroups could be determined without cross-reactions. Moreover the coexistence of other bacteria did not affect the results of the test. These results suggest that the staphylococcal coagglutination test is useful for detection and identification of Legionella, especially in environmental samples, and for serogrouping of isolates of L. pneumophila from clinical specimens.

Agglutination Tests↗