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H Kanbara

Publications and source records attributed to H Kanbara.

At least 55 records · Page 3Linked to original sources
PubMed1992

Sequence variation in the tripeptide repeats and T cell epitopes in P190 (MSA-1) of Plasmodium falciparum from field isolates.

The N-terminal part of p190, the precursor to the major merozoite surface antigens of Plasmodium falciparum, contains the T and B cell epitopes and tripeptide repeats. The p190 gene exhibits allelic dimorphism, but the tripeptide repeat-encoding region is the only exception to the dimorphic variations of the gene. To date, sequences available to document variations in the epitopes are very limited. Thus, in this study, the extent of the variation in these regions was analyzed using the polymerase chain reaction to amplify the DNA fragment encompassing these regions, followed by sequencing. Twenty-five gene clones were obtained from 19 isolates from the Mae Sod district in Thailand and their sequences were compared with those reported elsewhere. Results reveal 3 sequence types in the tripeptide-encoding region, and each contains a novel repetitive consensus nucleotide sequence. On the other hand, almost all nucleotide substitutions in block III are dimorphic. Identification of linkages of the dimorphic substitutions has led us to postulate 6 potential crossover sites, where intragenic recombinations of p190 alleles could occur. Sequences of T and B cell epitopes are highly conserved among these wild isolates and those from geographically diverse culture-adapted parasites.

Amino Acid Sequence↗
PubMed1991

New enzyme immunoassays for specific assay and general detection of Trypanosoma cruzi, epimastigotes.

A highly specific competitive enzyme-linked immunosorbent assay for the epimastigote of Tulahuen strain was developed by using the usual 3 immunological reagents, a rabbit antiserum specific for T. cruzi, epimastigote of Tulahuen strain, beta-D-galactosidase-labeled goat anti-rabbit immunoglobulin G and the solid-phase cell fragments of the epimastigote of Tulahuen strain. A new method, the selected antibody enzyme immunoassay (SAEIA) which generally detected all strains of the epimastigote tested with the same working range, was developed by changing only the solid-phase antigen to the epimastigote of Y strain among the 3 immunological reagents. Both assays permitted us to measure accurately as little as 1,000 parasites per assay tube. Scope of the SAEIA was limited to the epimastigote. Both life-cycle forms of T. cruzi which appear in mammals, amastigote and trypomastigote, and other kinetoplastids showed low cross-reaction values by the assay. The assay principle of the new method and a preliminary study to apply the SAEIA for finding the field T. cruzi-infected insect vectors were also reported.

Animals↗
PubMed1991

Coexistence of GP195 alleles of Plasmodium falciparum in a small endemic area.

Dimorphic variations in the genotype of the precursor to Plasmodium falciparum major merozoite surface antigens or gp195, among wild isolates in a small malaria parasite population were examined using Southern blot hybridization techniques. Hybridization, with DNA fragment probes and oligonucleotide probes derived from variable blocks of known gp195 alleles against 18 wild isolates from Mae Sod district in Thailand, revealed the existence of seven gp195 alleles, two of which were newly identified in this study. In four out of 17 patients, two different alleles coexisted in the circulation. It was furthermore noted that the seven alleles did not occur at the same frequency, but rather several alleles predominated in the population of P. falciparum in this small malaria field.

Alleles↗
PubMed1991

[Value of fatty acid imaging using 123I-beta-methyl iodophenyl pentadecanoic acid (BMIPP) to assess viability of infarcted myocardium].

To evaluate clinical value of a new fatty acid imaging tracer, 123I-beta-methyl iodophenyl pentadecanoic acid (BMIPP), 27 patients with myocardial infarction (MI) underwent BMIPP imaging at rest. The results were compared with those of thallium-201 imaging and contrast ventriculography. Of 100 hypoperfused segments on thallium-201 imaging, 34 segments (34%) showed lower BMIPP uptake than thallium-201, and remaining 66 segments showed similar distribution of those tracers. This discrepancy was more often observed in a patients with acute or subacute stages of MI (less than 4 weeks from onset) than those with chronic stage of MI (greater than 4 weeks) (75% vs. 47%; p less than 0.005). In addition, in the patients with chronic stage of MI, the regional wall motion abnormality was less severe in those showing discrepant BMIPP uptake than those showing concordant distribution (the wall motion score: 1.33 +/- 0.62 vs. 0.63 +/- 0.99; p less than 0.05). Furthermore, redistribution on stress thallium-201 imaging was more often observed in than those showing concordant distribution (12%) than those showing concordant distribution (12%) (p less than 0.005). These preliminary study indicates that discrepant distribution of BMIPP and thallium-201 may be often observed, particularly in recent MI and those showing less wall motion abnormality and redistribution on stress thallium-201 imaging. Thus, the combined study of BMIPP and thallium-201 has a potential for assessing tissue viability in patients with MI.

Adult↗
PubMed1990

[A basal cell carcinoma of the esophagus--a case report].

Reported is the case of a 58-year-old male who visited our hospital with the chief complaint of anorexia. Diagnosed as having an esophageal cancer, a subtotal esophagectomy was performed including the dissection of the tumor. According to the surgical findings, the tumor was not exposed to the tunica externa and no lymph node metastasis or infiltration to the pleura or a metastasis to the lung or liver was note. On histopathological examination a basal cell carcinoma of esophagus was determined but no squamous epithelium was seen. The carcinoma was the muscular propria, and neither infiltration into the epithelium nor invasion into the vessels was noted. The postoperative progress appeared good, however seven months later the patient died from multiple hepatic metastasis.

Basal Cell Carcinoma↗
PubMed1987

Comparison of virulent trypomastigotes with low-virulent ones derived from a single strain of Trypanosoma cruzi: infectivity to new fibroblasts from various organs of the mouse.

Previous experiments have shown that the infectivity of virulent trypomastigotes in L-cell culture was much more intensive not only for macrophages but also for newly cultured fibroblasts from the mouse heart as compared to low-virulent trypomastigotes in L-cell culture which had been derived from the same strain. On the other hand, the infectivity of virulent trypomastigotes for L-cells was less intensive. In the present work, new fibroblasts derived from muscles, skin, heart and kidney of newborn mice and established fibroblasts from mouse muscles were examined in terms of their susceptibility to trypomastigotes of different virulence. A slight difference of susceptibility to virulent trypomastigotes among new fibroblasts from different sources was found, i.e. fibroblasts derived from muscles and skin were more susceptible than those from heart and kidney. Growth of low-virulent trypomastigotes was suppressed in all new fibroblasts. This suppression was explained by the result that amastigote proliferation of a low-virulent strain was much slower in new fibroblasts from mouse muscles in spite of a similar penetrative ability of both kinds of trypomastigotes. Furthermore, a slight decrease in the susceptibility of new fibroblasts to virulent trypomastigotes was found depending on the length of time fibroblasts had been maintained.

Animals↗
PubMed1986

Mouse IgE-mediated paw anaphylaxis in mice and rats.

Anaphylactic swelling is induced in the hind paws of mice and rats by intravenous challenge of antigen 72 h after subplantar injection of mouse IgE-rich antiserum into the paws, and can be quantified rapidly and accurately by measuring paw thickness. The edema model described may serve as an alternative to passive cutaneous anaphylaxis for studying immediate allergic reactions with mouse homocytotropic antibodies and screening potential antiallergic drugs.

Animals↗
PubMed1985

A Japanese survey on first attempts of percutaneous transluminal coronary angioplasty.

Experiences of the initial application of percutaneous transluminal coronary angioplasty (PTCA) in Japan performed during 1980-1981 at the multicenter level were analyzed. A survey in 72 cases which were collected from 12 centers showed an overall success rate of 64.7%, unimproved stenotic lesions in 8.1% and unpassable lesions in 24.3% of the cases. Complications were death of the patient in 2(2.8%), acute myocardial infarction in 6(8.3%) and dissection of the coronary artery in 3 cases (4.2%). Aortocoronary bypass graft surgery was performed in 8 cases (11.1%).

Adult↗
PubMed1985

Comparative studies on surface antigenicity of Trypanosoma cruzi trypomastigotes from infected mouse blood and infected L-cell cultures.

Differences in the antigenicities of surface components of blood-form trypomastigotes and trypomastigotes derived from L-cell cultures were studied by agglutination and indirect immunofluorescent tests on living parasites using various antisera from rabbits and mice. Antisera from rabbits immunized with L-cell-derived trypomastigotes and antisera obtained from rabbits infected with L-cell-derived trypomastigotes showed similar titers in both the agglutination and immunofluorescent test. Moreover, both antisera exhibited higher titers against trypomastigotes derived from L-cell cultures than against blood-form trypomastigotes. No detectable agglutination titer against either blood-form or L-cell-derived trypomastigotes was observed with sera from (a) mice infected with blood-form trypomastigotes after previous immunization with blood-form trypomastigotes, (b) mice infected with blood-form trypomastigotes and then treated with Lampit, or (c) mice infected with slightly less virulent trypomastigotes from L-cells. However, detectable and almost equal titers were observed with sera from (a), (b) and (c) in indirect immunofluorescent tests. Mouse sera also exhibited higher titers against trypomastigotes derived from L-cells than against the blood-form type. However, mouse sera showed more pronounced differences than rabbit sera. These results suggest that there may be two types of trypomastigotes in infected animals and that the surface components of blood-form trypomastigotes have lower antigenicity.

Agglutination Tests↗
PubMed1983

Improved method for separation on CM-cellulose of the trypomastigote form of Trypanosoma cruzi from forms grown in fibroblast cell cultures.

Trypomastigotes grown in fibroblast cell (L-cell) culture were more effectively and more rapidly separated from other cells on a CM-cellulose column with culture medium (MEM with 10% calf serum) for elution instead of phosphate-saline-glucose buffer (PSG). This effective separation was shown to be due to the presence of serum. Trypomastigotes weakly adhered to CM-cellulose resin by the tip of the body (mainly the flagellar tip) when they were suspended with CM-cellulose resin in PSG. Serum seemed to disturb the adhesion of trypomastigotes to the resin, but not the adhesion of amastigotes and fibroblast cells. Therefore, only trypomastigotes were rapidly eluted from a CM-cellulose column in the presence of serum.

Animals↗
PubMed1983

Studies on the surface component of Trypanosoma cruzi amastigotes: determination of the specific antigen and characterization by enzyme treatment and electronmicroscopy.

A specific antigen to amastigotes of Trypanosoma cruzi was found by immunodiffusion. It was one of the predominant antigens against anti-amastigote serum and also against infected rabbit serum. This specific antigen was mainly eluted in the first peak from a Sephadex G-200 column and moved slowly on immunoelectrophoresis. It was shown to be present on the surface of amastigotes using antiserum to the specific precipitin line between the first fraction of amastigote antigen from the Sephadex G-200 column and the anti-amastigote serum. The surface component of amastigotes was found to be rich in carbohydrate by histochemical electronmicroscopy. The component was also shown to be susceptible to pronase and hyaluronidase, but resistant to trypsin, chondroitinase ABC and neuraminidase, by investigating the sensitivity to the lytic effect of fresh serum from unimmunized rabbits after enzyme treatment. The relation between the specific antigen and the surface component was discussed.

Animals↗
PubMed1983

Comparative studies on trypomastigotes of Trypanosoma cruzi from infected mouse blood and infected fibroblast cell (L-cell) culture.

The resistance to phagocytosis by macrophages and the penetration into fibroblast cells of blood form trypomastigotes of Trypanosoma cruzi were compared with those of trypomastigotes grown in fibroblast cell culture. On incubation for 24 h, blood form trypomastigotes were almost completely resistant to phagocytosis, but about 40% of the trypomastigotes from cell culture were phagocytized. On longer incubation, the resistance of both forms of trypomastigotes decreased gradually. The penetrating ability of blood form trypomastigotes was much lower than that of trypomastigotes from cell culture. Infection of mice with blood form trypomastigotes resulted in less proliferation of parasites in the liver and spleen than that with trypomastigotes from cell culture. From these results, the existence of two functionally different forms of trypomastigotes in infected mice and in infected fibroblast cell culture, respectively, is discussed.

Animals↗
PubMed1979

Electronmicroscopic observations on lysis of Trypanosoma cruzi epimastigote by normal rabbit serum.

The lytic effects of serum from a non-immunized rabbit on epimastigotes of Trypanosome cruzi were studied by electronmicroscopy. The first detectable change was the appearance of a fuzzy deposit over the whole surface of the epimastigote. Soon after this, pellicular microtubules disappeared without change of axonemal microtubules. Circular lesions were observed by negative staining, corresponding to the lesion of antibody-mediated lysis caused by complement.

Animals↗