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Biomedical subjects

K Ohta

Publications and source records attributed to K Ohta.

At least 685 records · Page 38Linked to original sources
PubMed1988

Experimental hypersensitivity pneumonitis in the mouse: histologic and immunologic features and their modulation with cyclosporin A.

A murine model of hypersensitivity pneumonitis (HP) was established with transnasally administered Thermoactinomyces vulgaris (Tv) bacilli. Bronchoalveolar lavage (BAL) of experimental animals revealed marked increase in the total cell, lymphocyte, and macrophage numbers; the findings were similar to those in human HP. The BAL lymphocytes were mostly Thy 1.2 positive. Lyt-1 positive cells predominated Lyt-2 positive cells. Anti-Tv IgG antibodies and delayed-type hypersensitivity footpad reactions against Tv were detected in animals with HP. Cyclosporin A (CyA), a potent immunosuppressive drug, had marked effects on the development of HP in this model. When CyA was administered throughout the course of Tv inoculations, the granulomatous pneumonitis was markedly suppressed, and an increase in BAL lymphocytes, Thy 1.2 positive cells, was suppressed. When CyA was administered only during the first half period of the Tv treatment, suppression of the disease was minimal; when CyA was administered in the latter half, both the HP lesions and the increase in BAL cell lymphocyte numbers were significantly suppressed. These results indicate that a series of transnasal administration of Tv in mice may provide a good model for human HP.

Alveolitis, Extrinsic Allergic↗
PubMed1988

Human tonsillar IgE biosynthesis in vitro. II. Analysis of T cell regulation with monoclonal antibodies.

Phenotypes of T cells regulating human tonsillar IgE biosynthesis in vitro were studied by use of Leu 2a and Leu 3a monoclonal antibodies that recognize T cell subsets. B cells cultured with Leu 3a+-enriched populations (B cells plus T3a) produced significantly more IgE and IgG in the presence of pokeweed mitogen than B cells with the Leu 2a+-enriched populations (B cells plus T2a) (p less than 0.001 for IgE and p less than 0.001 for IgG). No significant differences were observed in IgE and IgG synthesis between the cultures of B cells alone and B cells plus T2a. T2a, but not T3a cells, significantly suppressed IgE synthesis (p less than 0.05 for geometric means and p less than 0.001 for percent suppression) when the cells were added to cultures of B cells plus T3a. Suppression of IgG synthesis was not observed under conditions that suppressed IgE synthesis, suggesting qualitative and quantitative differences in regulation of production of these isotypes. When T2a cells were irradiated, the suppressor activity disappeared. When graded numbers of T3a cells were added to B cells, it was noted that IgE synthesis first increased and then decreased as the numbers of T3a were increased. When the T3a cells were irradiated, IgE biosynthesis was suppressed at lower T/B ratios (less than 1 in four of five experiments) and was enhanced at higher T/B ratios (greater than 1 in all five experiments). Similar results were observed in experiments with OKT4 and OKT8 monoclonal antibodies. It is concluded that phenotypes of helper T cells for IgE synthesis are Leu 3a+ or OKT4+ and that IgE suppressors are predominantly Leu 2a+ or OKT8+ and are radiosensitive, as reported for regulation of other isotypes. However, it is suggested that Leu 3a+ and OKT4+ cells consist of radioresistant and radiosensitive helper cells and, presumably, a minor population of suppressor cells.

Antibodies, Monoclonal↗
PubMed1988

Comparison between the photoelectric method and H2 clearance method for measuring cerebrocortical blood flow in cats.

The photoelectric method using carbon black as a nondiffusible tracer of blood was compared with the hydrogen clearance (H2) method in nine anesthetized cats. A photoelectric apparatus and H2 electrode were applied to a small region of the cerebral cortex (left ectosylvian gyrus) for simultaneous measurement of the regional CBF. The values of CBF(H2) and CBF(photoelectric) were 50.7 +/- 19.2 and 52.1 +/- 14.5 ml.100 g-1.min-1, respectively. CBF(H2) and CBF(photoelectric) were found to correlate well (r = 0.588, p less than 0.01) when changes in CBF were induced by CO2 inhalation, exsanguination, hyperventilation, and occlusion of the middle cerebral artery. The correlation between CBF(H2) and CBF(photoelectric) was much better in the case of intraindividual comparisons (r = 0.957, p less than 0.01). In addition to its merits in common with the H2 clearance method, such as handiness, low cost, and strict regionality, the photoelectric method displayed the following advantages: time-to-time measurements of CBF (less than 20 s), immediate display of the microcirculatory flow pattern, and simultaneous monitoring of cerebral blood volume. However, measurements from deep structures of the brain are better performed by the H2 method despite the disadvantage of the use of a potentially explosive gas.

Animals↗
PubMed1988

Regional changes in the cellular level of adenine nucleotides in ischemic rat brain subjected to single embolization.

Regional changes in adenine nucleotides in the rat brain were studied after 1 h of ischemia produced by the embolization method. The animals were divided into three groups according to neurological symptoms: sham-operation group, group A (hemiparesis only), and group B (hemiparesis with unconsciousness). Marked ATP depletion was detected in the hippocampus on the embolized side and extended to the other regions on the same side in group B. The results suggest that this damage in regional energy metabolism arises from regional reduction in blood flow and/or tissue vulnerability. ATP levels in the hypothalamus, hippocampus, and striatum on the opposite side of embolization decreased markedly in group B, and may be caused by extension of brain edema or diaschisis.

Adenine Nucleotides↗
PubMed1988

Pathogenesis of progressive muscular dystrophy: studies on free radical metabolism in an animal model.

Evidence to suggest the presence of abnormal metabolism of oxygen free radicals in progressive muscular dystrophy is presented using an animal model. In the superficial pectoral muscles of dystrophic chickens, enzyme activities regulating the metabolism of oxygen free radicals, i.e., catalase, superoxide dismutases and glutathione peroxidase, were significantly elevated within 1 week of hatching. Activities of related enzymes, i.e., glutathione reductase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase were also elevated. In contrast, the specific activity of phosphofructokinase, the rate-limiting enzyme of the glycolytic pathway, was normal during the first 4-week period. These results suggest that there is an increased turnover of oxygen free radicals in the dystrophic muscle. This concept appears important in a further investigation of the pathogenesis and treatment of progressive muscular dystrophies.

Animals↗
PubMed1988

Identification and characteristics of actinomycetes useful for semicontinuous treatment of domestic animal feces.

Selected strains of actinomycetes useful for practicing semicontinuous treatment of swine and poultry feces were identified as Streptomyces antibioticus S-4, S. puniceus N-50-2, S. nigrifaciens N-9-3, Thermoactinomyces vulgaris HIR-60, and Thermomonospora viridis HIR-50. These five obligately aerobic strains grew preferably on nonsterilized fresh swine feces in 24 h without any additives. They assimilated offensive volatile fatty acids in the swine and poultry feces. Cultures of these five strains were mixed and used as seed for the practical treatments of 1 ton of swine feces over the wide temperature range of 15 to 60 degrees C. Strain HIR-50 grew most predominantly on both fresh swine and poultry feces at 50 to 55 degrees C and decomposed uric acid. For the efficient penetration of mycelia into the feces, manures were mixed once a day so as not to break the solid mass, and the dehydration rate of feces had to be controlled in proportion to the mycelial growth rate. The actinomycete biofertilizer thus manufactured in 10 days was odorless and promotive of plant growth.

Journal Article↗
PubMed1988

A novel 53 kDa actin binding protein from porcine brain--further biochemical and immunological characterization.

We have previously described some of the characteristics of an actin binding protein, 53 K protein, purified from porcine brains. The purification procedure was revised in order to investigate of this actin binding protein further. A Scatchard plot analysis showed that the association constant between actin and the 53 K protein has around the same value as those reported for the fascin-actin and for the filamin-actin interactions. The binding experiments also demonstrated the occurrence of competitive binding with other actin binding proteins such as filamin, alpha-actinin, caldesmon and tropomyosin for the actin filament. Antibody was produced against brain 53 K protein and further purified on an affinity column. Immunoblot analysis using the antibody showed that this protein is localized in both the soluble and membraneous fraction of the brain. Other tissues such as liver and lung also contain 53 K protein. The immunoblot analysis also revealed that the gelation product of rat brain extract described by Palmer et al. contains immunoreactive polypeptides having slightly lower molecular weights and more basic isoelectric points than porcine brain 53 K protein. Immunological localization of the 53 K protein within HeLa and BS-C-1 cells showed that this protein is distributed throughout the cell in small granules, and in some regions of the cell, these granules were aggregated into much larger granules.

Actins↗
PubMed1988

[Studies on absorption and excretion of rokitamycin dry syrup in healthy volunteers].

The absorption and excretion of rokitamycin (RKM) in dry syrup form for children were studied following oral administration to fasted healthy volunteers with high gastric acidity as a suitable model to estimate bioavailability of RKM in children. In a comparative study on tablet and dry syrup forms, peak plasma concentrations of RKM and areas under plasma concentration-time curve (AUC) values were calculated using the trapezoidal rule. RKM dry syrup gave about 84 and 86% of these values for RKM tablet. Urinary recovery of RKM in 8 hours with the administration of dry syrup was also about 80% of the value obtained with tablet. Judging from these results, the bioavailability of RKM administered as dry syrup, was fairly close to that obtained with RKM tablet. The AUC values were dose dependent when examined with dose levels of 300, 500 and 800 mg administered as RKM dry syrup. The AUC value and urinary recovery of RKM administered as dry syrup were 3-4 times higher than these values for midecamycin acetate administered also as dry syrup.

Absorption↗
PubMed1988

[Increases in the modified surgery in early cancers].

Early cancers are small in size and localized; many of them have no infiltration or metastasis. It has been gradually clarified what procedure of reduced operation can be feasible without fail to its radicalness to what type of early cancer, as a result of detailed studies on the findings concerning the development of early cancers as well as evaluations of recurrent cases and distant results. Techniques of reduced operation for the treatment of cancers of the thyroid, mammary glands, female reproductive organs and stomach have been improved as early cancer patients increase in number and our understanding of the pathogenesis of early cancers is promoted.

Breast Neoplasms↗
PubMed1988

[Clinical study of hypertensive subcortical hemorrhage: surgical indication and long-term, functional prognosis].

There has been no report available for determining surgical indications in hypertensive subcortical hemorrhage based on functional prognosis. The authors then studied the clinical results of hypertensive subcortical hemorrhage for evaluating the surgical indication in relation to functional prognosis. Sixty-five patients with hypertensive subcortical hemorrhage diagnosed by CT scan who were hospitalized to Matsue Red Cross Hospital from January 1980 up to December 1986 were studied. The 44 male and 21 female patients ranged in age from 37 to 86 years, and 38 of them were operated on. The results were as follows: 1) Patients with grade I (Kanaya's neurological grading) or a volume of hematoma less than 30 ml should be treated with conservative therapy. Those with grade II and III or a volume of hematoma = 30 - 50ml should be treated in accordance with proper therapeutic method, taking into consideration the site of the hematoma. Patients with more than grade IVa or a volume of hematoma greater than 50ml would be in danger of losing their lives unless surgical therapy was performed. 2) The follow up study of the patients' long-term prognosis after discharge revealed the majority of the patients showed aggravation of the illness and/or death due to cerebral apoplexy-like attack and re-bleeding. It is necessary to follow up these cases with careful systemic control, including monitoring of blood pressure.

Brain↗
PubMed1988

[Treatment of cancer of the esophago-gastric junction with special reference to dissection of the lymphatic system].

No means have yet been devised for detecting cancer of the esophago-gastric junction at an early stage, and no effective chemotherapy or irradiation regimen for this area is yet available. Recently, a very important lymphatic pathway and extension route for E. G-junction cancer has been discovered. A new operative procedure involving a thoraco-abdominal approach, wide dissection of the lymphatic system and safe reconstruction is discussed in this paper.

Adenocarcinoma↗
PubMed1988

[Concentrations of cefuroxime in the skin].

Concentrations of cefuroxime (CXM) in the skin and the serum of 24 patients were examined. CXM (0.75 g, 1.5 g) was administered to these patients intravenously in one shot. The skin and the serum were collected at 30 and 60 minutes after the injection. Concentrations of CXM in the skin were following: 0.75 g, 30 min.; 11.4 +/- 5.3 micrograms/g 60 min.; 9.5 +/- 4.7 micrograms/g 1.5 g, 30 min.; 17.1 +/- 6.8 micrograms/g 60 min.; 15.7 +/- 13.2 micrograms/g Concentration ratios (skin/serum) at 60 minutes after the injection were from 72.5% to 79.2%. The binding ratio of CXM to serum protein was 41%, which was lower than most other antibiotics. High concentration levels of CXM were maintained in the skin for a long time. Based on this study, we consider that CXM is effective in the skin surgery.

Cefuroxime↗