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Biomedical subjects

J Chiba

Publications and source records attributed to J Chiba.

At least 127 records · Page 7Linked to original sources
PubMed1991

[Simultaneous assessment of wall motion and myocardial perfusion by technetium-99m methoxy isobutyl isonitrile].

The aim of this study was to assess whether or not myocardial uptake of Technetium-99m methoxy isobutyl isonitrile (Tc-MIBI) indicated myocardial viability. We performed simultaneous Tc-MIBI angiography and myocardial SPECT at rest on 12 patients with suspected coronary artery disease. Left ventricle was divided into 3 segments, and regional wall motion was graded as normal, hypokinesis and akinesis/dyskinesis. Myocardial uptake of Tc-MIBI was assessed as normal, reduced and absent in each segment. In segments with normal and reduced Tc-MIBI uptake, 7% (2 of 28) and 33% (2 of 6) showed wall motion abnormalities of akinesis/dyskinesis, respectively. However, all segments with absent Tc-MIBI uptake had asynergy of akinesis/dyskinesis (2 of 2, 100%). Myocardial Tc-MIBI uptake at rest indicated wall motion abnormalities and was considered to be useful for the evaluation of myocardial viability. First-pass radionuclide angiography followed by myocardial SPECT with Tc-MIBI demonstrated to be useful for the simultaneous assessment of the left ventricular wall motion and myocardial perfusion.

Coronary Circulation↗
PubMed1990

Herpes zoster in patients with polymyositis and dermatomyositis.

Twenty-two patients with polymyositis and dermatomyositis (PM-DM) were retrospectively studied with regard to development of herpes zoster. Herpes zoster occurred with high frequency in patients with PM-DM. The clinical courses of zoster infections were uneventful; no severe complications nor deaths occurred, and only one patient had post-therapeutic neuralgia. No specific therapy for this infection was necessary. Zoster tended to occur in the inactive stage of PM-DM. PM-DM patients with herpes zoster had a significantly higher incidence of antinuclear antibody. There seemed to be no relationship between steroid therapy and herpes zoster infection.

Adult↗
PubMed1990

[A case of polymyositis associated with unusual CPK isoenzyme pattern and myocardial imaging].

A case of polymyositis (PM) associated with abnormal creatinine phosphokinase (CPK) isoenzyme pattern and Thallium-201 (Tl-201) myocardial imaging was reported. No such case has ever been reported in Japan. A 44-year-old female was admitted for evaluation of muscular weakness of proximal limbs and polyarthralgia. On laboratory examinations, the serum levels of CPK, aldolase and transaminase were markedly elevated. The electromyograms revealed a typical myogenic pattern. On the pathological findings, the principal changes in muscle tissue consisted of inflammatory cell infiltration. Based on those findings, she was diagnosed as having polymyositis. In our patient, there were three characteristics as following; (1) CPK-MB of CPK isoenzyme showed persistent high levels, (2) macro CPK in Electrophoresis of CPK was observed, (3) Tl-201 myocardial imaging revealed multifocal perfusion defects and localized defect in left ventricular inferior wall. She was started on therapy with prednisolone (30 mg/day). The clinical and laboratory manifestations were improved. Abnormal CPK isoenzyme pattern and myocardial imaging were also improved parallel with disease activity of PM. Thus, this case indicated the relation of the damage of skeletal muscle and cardial involvement in PM to unusual CPK isoenzyme pattern. Then wer reported this case.

Adult↗
PubMed1990

[Effect of aminophylline on thallium-201 washout rate during myocardial perfusion imaging with dipyridamole].

Thallium-201 myocardial perfusion imaging with dipyridamole was performed on 78 patients (pts) with suspected coronary artery disease (CAD). Twenty eight pts had normal coronary arteries (control group), and 50 pts had 50% or greater stenosis in one or more major coronary arteries (CAD group). In control group, aminophylline (Am) was infused intravenously on 12 pts during dipyridamole testing. Mean washout rate (WR) of these 12 pts was greater than that of 16 pts without Am (42% vs 35%, p less than 0.01). Then normal limit of WR was defined separately from the pts of control group with and without Am. The sensitivity for detecting the pts with CAD by WR analysis which normal limit was calculated separately with and without Am was 92% (46/50). When normal limit of WR was determined from all pts in control group, the sensitivity decreased to 84% (42/50). Am significantly affected thallium-201 washout during dipyridamole testing. WR of CAD pts should be estimated by specific set of normal limit with and without Am.

Aminophylline↗
PubMed1990

Antitumor activity of T-2 toxin-conjugated monoclonal antibody to murine thymoma.

T-2 toxin (T-2(4)), one of the trichothecene mycotoxins produced by various gerera of Fusarium spp., is a potent inhibitor to the syntheses of protein and DNA in mammalian cells. The selective cytotoxicity of T-2 toxin-conjugated anti-EL-4 monoclonal antibodies (T-2-mAb) was investigated against murine thymoma EL-4 cells in vitro and in vivo systems. At first T-2 was converted to T-2 hemiglutarate by glutaric anhydride. Then T-2 hemiglutarate was activated to 3-[4-(N-succinimidoxycarbonyl)-butyryl]-T-2 (T-2-G-OSu) by N-hydroxysuccinimide. Thus obtained T-2-G-OSu was conjugated with mAb specific for EL-4 cells. The T-2-mAb markedly inhibited the proliferation of cultured EL-4 cells, but no such cytotoxic effect was observed against irrelevant SP2/0 cells. The cytotoxicity of T-2-conjugated normal gamma globulin (T-2-nGG) against EL-4 cells was far less than that of the above T-2-mAb. Ammonium chloride and monensin, inhibitors of lysosomal enzymes, enhanced the cytotoxicity of T-2-mAb. The presence of both 2-deoxyglucose together with sodium azide, inhibitors of energy-dependent reaction, reduced the cytotoxicity of T-2-mAb. Therefore, the selective binding to the target cells followed by an energy-dependent endocytosis and an intracellular liberation of T-2 by hydrolysis may account for the cytotoxicity of the T-2-mAb. In mice pre-transplanted with EL-4 cells, T-2-mAb increased the mean survival time (MST) with a direct dosage dependence.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

A sensitive enzyme-linked immunosorbent assay of ochratoxin A based on monoclonal antibodies.

We prepared seven monoclonal antibodies (mAbs, OTA.1, 2, 3, 4, 5, 6 and 7) which were reacted with ochratoxin A (OTA), and have developed a specific and highly sensitive enzyme-linked immunosorbent assay (ELISA) for detection of OTA. The mAbs, OTA.1, 3, 4, 5 and 7, specifically reacted with OTA but much less with its analogs, ochratoxin B (OTB, about 1% of OTA) and ochratoxin alpha (OT alpha, less than 0.1% of OTA). One of the mAbs, OTA.2, equally reacted with OTA and OTB but hardly at all with (4R)-4-hydroxyochratoxin A or OT alpha (less than 0.1% of OTA). All of the mAbs reacted with ochratoxin C. None of the mAbs reacted with coumarin, 4-hydroxycoumarin or L-beta-phenylalanine. In the competitive ELISA with OTA.1 and OTA.7, the lowest detectable amount of standard OTA in solution was 50 pg/ml (2.5 pg per assay). This assay was applied for the quantitation of OTA added to chicken meat, wheat flour, porcine plasma and bovine serum. With minimal sample preparation, reliable and reproducible determinations were possible when concentrations of OTA were higher than 0.1-1 ng/g.

Animals↗
PubMed1989

Monoclonal antibodies against alpha toxin of Clostridium perfringens.

Ten distinct monoclonal antibodies (MAbs) against alpha toxin of Clostridium perfringens were produced by the fusion of SP2/O with spleen cells of mice immunized with alpha toxoid, and alpha toxin mixed with or without ethylenediamine-tetraacetate (EDTA). The antibody activity was evaluated by antigen-binding activity in an enzyme linked immunosorbent assay (ELISA), by phospholipase C (PLC)-neutralizing activity using both egg yolk lecithin and p-nitrophenylphosphoryl-choline (PNPPC) hydrolysis reactions and by anti-lethal activity in mice. Since the toxin-neutralizing activities of each MAb were not parallel, it has been suggested that the three biological activities may not be located in the same site in the toxin molecule. This report also describes the development of a simple purification of the toxin by affinity chromatography and a sensitive immunoassay for quantitation of the toxin using the monoclonal antibody.

Animals↗
PubMed1988

Thymic accessory cells required for the increased responsiveness of thymocyte subpopulations to interleukin 1-like monokine in guinea pigs.

The proliferative response of guinea-pig thymocytes to co-mitogenic stimulation with phytohaemagglutinin and the guinea-pig interleukin 1 (IL-1)-like lymphocyte-activating monokine was lost by removing the cells that adhere to a Sephadex G-10 (G-10) column or the cells of low density in a Ficoll-Conray gradient. The diminished response in the G-10 non-adherent thymocyte or high-density thymocyte fraction was restored by the addition of a macrophage-depleted G-10 adherent thymocyte fraction or a low-density, Ia-positive thymocyte fraction but not by the addition of peritoneal macrophages. These results suggest that the accessory cells which mediate the increased responsiveness of thymocytes to the IL-1-like monokine existed in G-10 adherent cell fractions and the cells with this accessory function were not macrophages. The accessory cells were shown to be of low density, glass-non-adherent, G-10-adherent, Fc receptor-negative, and Ia-positive. These results also suggest that the G-10-non-adherent and high-density thymocyte subpopulation, which is unresponsive or responds very little to the IL-1-like monokine by itself, acquires responsiveness to the monokine and proliferates by stimulation with the IL-1-like monokine and lectin in the presence of the accessory cells.

Animals↗
PubMed1988

[A strategy for the production of human monoclonal antibodies].

The EBV-hybridoma system will be, at present, the best method for rescuing low-frequency tumor-reactive B-cell clones in cancer patients to produce human monoclonal antibodies reactive with tumor-related antigens. To improve this system, we established a nobel fusion partner, 3HL3-6J(C5), which produced hybridomas efficiently (greater than 2 x 10(-5)) after fusion with EBV-transformed B cell lines. TAPC-301 and C5TK1, anti-SRBC IgM and anti-HBs IgG producer, respectively, which provided by Prof. Y. Ono, were used as standard EBV-transformed B cell lines. Their hybridomas were good antibody producers (greater than 10 micrograms/10(6) cells/24 hrs) and their cloning was relatively easy. The fusion rate was improved further when electrofusion was carried out instead of the conventional PEG fusion. Using PBL from a hepatoma patient, human monoclonal autoantibodies reactive with some cytoskeleton structure were easily produced by means of this system.

Antibodies, Monoclonal↗
PubMed1988

[Study on the effectiveness and safety of cefmenoxime in the treatment of respiratory tract infections. Tendency toward clinical hemorrhage related to the treatment].

The effectiveness and safety of cefmenoxime (CMX) in the treatment of respiratory tract infections were evaluated, mainly in relation to the appearance of hemorrhagic tendency. Out of 80 patients treated in this study, 57 were treated with CMX alone, and an effective rate was determined to be 75.4%. As for a tendency toward hemorrhage, none of the patients clinically exhibited a hemorrhagic tendency, while the prolongation of prothrombin time (PT) and/or activated partial thromboplastin time (APTT) was seen in 3 patients (3.8%), who were all at ages over 63. The prolongation of APTT was clearly related to CMX in 1 patient. Although the causal relation between CMX and the prolongation of PT or APTT was unclear in the remaining 2 patients because they had severe primary diseases (lung cancer and respiratory failure due to chronic obstructive lung disease in addition to severe hepatic disorder and received combination treatment with anticancer agents or other antibiotics), CMX might have a role in causing these phenomena. Even though none of the patients showed a hemorrhagic tendency clinically arousing problems, we should be careful in using CMX in the treatment of the aged and patients in poor general conditions because PT and/or APTT was observed to prolong with the use of CMX in some patients.

Adolescent↗