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Biomedical subjects

S Matsubara

Publications and source records attributed to S Matsubara.

At least 343 records · Page 19Linked to original sources
PubMed1984

Ex vivo preclinical evaluation of membrane plasma separators.

Four different types of hollow-fiber membrane plasma separators, constructed of cellulose acetate, polyvinyl alcohol, polyethylene, and polymethylmethacrylate membranes, were evaluated in ex vivo dog perfusions under conditions simulating their clinical use. An arteriovenous (A-V) fistula constructed in the dogs for blood access enabled repeated access to be achieved without surgical intervention. All modules produced transient leukopenia and a reduction of platelet counts. The polymethylmethacrylate module showed minimum reductions of white blood cell counts and CH50. The early leukocyte count reduction in membrane plasmapheresis is most likely related to the magnitude of complement activation by the membrane, as is seen with hemodialysis.

Animals↗
PubMed1983

A clinico-pathological study of chronic hereditary motor neuropathy.

Forty cases of chronic hereditary motor neuropathy (CHMN) were divided into five categories according to the distribution of muscle atrophy; they were proximal, facioscapulohumeral, bulbospinal, distal and scapuloperoneal forms. Their clinical features and laboratory data were analysed, and muscle biopsies from 32 of them were studied by histological, histochemical and electron microscopical methods. An attempt at quantitative assessment of the histological changes was also made. All muscle biopsies showed a mixture of neurogenic and 'myopathic' changes in varying proportions. They showed more 'myopathic' changes than Werdnig-Hoffmann's disease, amyotrophic lateral sclerosis and other neurogenic atrophies except Charcot-Marie-Tooth disease. There was marked variation in the average number of atrophied muscle fibers contained in grouped atrophy. Frequently, deranged internal structure of the muscle fibres was revealed both by histochemical and electron microscopical methods. Based on the evidence of heterogeneity of CHMN in respect of genetics, clinical features and histological changes, it was speculated that CHMN represents a group of diseases which involves primarily different parts of the motor units.

Adolescent↗
PubMed1983

Therapeutic approach to experimental autoimmune myasthenia gravis by dantrolene sodium.

Experimental autoimmune myasthenia gravis in rats was treated with dantrolene sodium (20 mg/kg/day) from 18th to 34th postinoculation day. At the end of the experimental period, day 35 postinoculation, the drug was shown to improve the disease as suggested by clinical observation and by larger MEPP amplitude and lower curare sensitivity without significant change in titers of anti-acetylcholine receptor antibody. Possible mechanisms by which the disease could be affected by the dantrolene-induced accumulation of free calcium in the subcellular store were discussed in relation to roles of calcium in regulation of the receptor protein and related immunity.

Animals↗
PubMed1983

Quantitative aspects of the receptor binding of cytokinin agonists and antagonists.

Congeneric 4-anilino- and 4-(alkylamino)-2-methylpyrrolo[2,3-d]pyrimidines showed cytokinin and anticytokinin activities, depending on the structure of their 4-substituents, and the antagonistic nature of the latter was established kinetically. The effect of the substituent on these activities was analyzed quantitatively by using physicochemical parameters and regression analysis to give a single, common equation for both the agonists and antagonists. The results indicated that the maximum width of the N4 substituents is an important factor both for binding to the receptor, thus the extent of activity, and for the quality of activity, agonistic or antagonistic. The electron-withdrawing effect and hydrophobicity of the substituents further enhance binding and, thus, activity, irrespective of the quality of the activity. These results coincide with and/or provide evidence for the hypothesis that in hormonal action, agonist binding causes a conformational change of an otherwise inactive receptor to the active form and that antagonists are species that bind similarly to the receptor but do not cause the effective conformational change.

Arabidopsis Proteins↗
PubMed1983

Characterization of polyethylene membrane for plasma separation.

Three types of polyethylene hollow fiber membranes (Mitsubishi, Tokyo) were evaluated for plasma separation: EHF-Type 1 (lowest porosity and smallest inner diameter), Type 2 (medium porosity and diameter), and Type 3 (highest porosity and largest inner diameter). Characterization of these membranes led to the selection of the Type 3 membrane as the best, based on in vitro studies of filtration and sieving properties. Analysis of the data suggests that pore size and pore number (density) are more optimal for this membrane. Ex vivo studies of the Type 3 membrane showed high sieving (greater than 0.9) for albumin, total protein, and total cholesterol; each was stable over time. No significant hemolysis was observed.

Animals↗
PubMed1983

Relation between extension of non-Hodgkin's lymphoma and lymphographic findings.

The relationship between the degree of lymph node foaminess observed in bipedal lymphadenograms and absolute peripheral lymphocyte counts in non-Hodgkin's lymphoma was analyzed with regard to the initial location, clinical stage, histologic subtype, and bulkiness of the disease. In the nodal type of disease with supra-diaphragmatic presentation, an inverse relation was often found between the peripheral lymphocyte count and the foaminess score. However, if the disease originated in the infra-diaphragmatic regions no such relation was found. The implications of these observations are discussed.

Humans↗
PubMed1983

Cryogel studies for the optimization of cryofiltration (CF) therapy.

This study has shown that cryofilter plugging correlates with pretreatment pathologic macromolecule concentrations (e.g. rheumatoid factor and immune complexes) in the treatment of patients with rheumatoid arthritis. Pathologic macromolecules are concentrated relative to albumin in the cryogel. Molecular aggregation in the cryogel depends upon heparin concentration, exhibiting maximum aggregation in a specific range of heparin concentrations. Molecular aggregation in cryogel increases with decreasing temperature. In the use of cryofiltration in over 50 rheumatoid arthritis patients, clinical improvement has accompanied the removal of cryogel and the pathologic macromolecules it contains. Filter plugging or cryogel formation may be indicators of disease activity. Formation of cryogel is variable depending upon type of disease, severity of disease, temperature, heparin concentration, and membrane structure. These factors are important parameters to consider to optimize conditions for removal of cryogel and for continuing improvement of plasma therapeutic techniques for the treatment of rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed1983

[Locked-in syndrome with bilateral midbrain infarcts--report of an autopsy].

A case of "Locked-in" syndrome with bilateral midbrain infarcts was reported. A 51-year-old man had a memory disturbance and a change of his personality after head trauma, and then became rapidly "Locked-in" state. He was quadriplegic and bulbar paralytic, but ocular movements were preserved. Left VAG showed the narrowing of the basilar artery and there was a striking anastomosis between the SCA and PICA. Neuropathological findings were as the following; 1) The lateral two third of bilateral cerebral peduncles were extensively infarcted. 2) There were contusion of the left frontal orbital surface and the ischemic infarction of the left frontal white matter. 3) Two small infarcted lesions were found in the ventral pons without involving the pyramidal tracts. 4) Additional findings were retrograde degeneration of the medial nucleus of the left thalamus from the left frontal orbital lesion, and were loss of the Purkinje cells and neurons of pontine nucleus from the infarction of the middle cerebellar peduncle. Tegmentum of the midbrain, pons and medulla were preserved, which was considered to be due to the anastomosis of the SCA and PICA. Bilateral midbrain infarcts are responsible lesions in this case and it seems that "Locked-in" state is not synonymous with the "Ventral pontine syndrome".

Cerebral Cortex↗
PubMed1982

Effects of contrast medium on radiation-induced chromosome aberrations.

The effects of contrast material (meglumine iothalamate) on radiation-induced chromosome aberrations were investigated in studies on the lymphocytes of patients who had undergone diagnostic radiography and in in vitro experiments with diagnostic x rays and 60Co gamma rays. Chromosome and chromatid aberrations were found to increase significantly with increasing concentrations of contrast material that were added at irradiation. However, the aberrations were not associated with elevation of the ratio of dicentric and ring chromosomes to the number of cells with unstable chromosome aberrations at the first mitosis. Lymphocytes irradiated in the absence of contrast material did not show an increase in chromosome-type aberrations when the agent was given in increasing concentrations during subsequent incubation, but there were greater numbers of chromatid gaps and breaks. When lymphocytes were exposed to 400 R (103.2 mC/kg) of 60Co gamma rays, the presence of contrast agent did not increase the yield of dicentric and ring chromosomes, but induced a marked delay in cell proliferation, especially in lymphocytes with more heavily damaged chromosomes. In additional examination, the contrast agent itself induced sister chromatid exchanges in lymphocytes.

Adolescent↗
PubMed1982

Extranodal non-Hodgkin's lymphoma in the head and neck. Irradiation and clinical course.

A retrospective analysis was performed of localized extranodal non-Hodgkin's lymphomas in the head and neck region treated with irradiation. Histopathologic reevaluation revealed 94 per cent with a diffuse type. The lesions were as a rule locally cured with doses ranging from 30 to 50 Gy. Relapses in localized stage I and II patients were, however, not seldom observed in distant extranodal sites. Gastrointestinal relapse in cases with lesions originally located in Waldeyer's ring was thus frequently observed, and the probability of multiple or systemic involvement should be considered also when the disease is located in the oral cavity or sinus region. The value of systemic examination for staging purposes is discussed.

Adolescent↗