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Biomedical subjects

K Usui

Publications and source records attributed to K Usui.

At least 91 records · Page 5Linked to original sources
PubMed1990

Isolation of tryptic fragment of antigen from mitochondrial inner membrane proteins reacting with antimitochondrial antibody in sera of patients with primary biliary cirrhosis.

Most of the sera from patients with primary biliary cirrhosis contains antimitochondrial antibodies, which react with four proteins of the mitochondrial inner membrane. We reported in a previous paper that when beef heart mitochondrial inner membrane proteins were digested by trypsin, a new reactive 36 kDa fragment with antimitochondrial antibody was obtained. This 36 kDa fragment derives from original 70 kDa protein because the monoclonal antibody specific to 70 kDa protein reacts with the 36 kDa band equivalent to 70 kDa band. The 36 kDa fragment was purified using an affinity column conjugated with an immunoglobulin-rich fraction of primary biliary cirrhosis serum containing antimitochondrial antibody, preparative electrophoresis and high-performance liquid chromatography using a reverse phase column. The final preparation showed a single band in sodium dodecyl sulfate polyacrylamide gel electrophoresis. Its amino acid composition is in good agreement with that of the subunit binding domain of the pyruvate dehydrogenase complex E2 from bovine heart.

Adult↗
PubMed1990

Growth of the Cellular Slime Mold, Dictyostelium discoideum, Is Gravity Dependent.

The effect of artificial gravity on the growth of a microorganism, Dictyostelium discoideum, was studied and the following results were obtained: (a) Germination efficiency increased as gravity increased up to 3 gravities. (b) Cell differentiation was influenced by gravity. Retardation of spore formation or reduction in the spore fraction was observed at hypergravity. (c) Fruiting bodies were taller at hypergravity and smaller at simulated microgravity when compared at 1 gravity. It is suggested that modulation of gravity provides useful information on the mechanisms of life.

Journal Article↗
PubMed1990

Extracranial metastases of malignant ependymoma--case report.

A case of malignant ependymoma with extracranial metastases is reported. A 59-year-old male was admitted to our hospital with vomiting and ataxia. Following computed tomographic (CT) scanning indicating a ring-like enhanced mass in the cerebellum, the tumor was subtotally removed in December, 1985. Histological diagnosis was malignant ependymoma. A second operation was performed in February, 1987, due to recurrence of the tumor in the fourth ventricle. Postoperative radiation therapy at a total dose of 7780 rads was given over 2 years. Eleven months after radiation therapy was completed, he reported cough and multiple skin metastases. Chest x-rays showed metastases at the right hilus. Repeated CT scans revealed separate frontal cerebral metastatic tumors. He died of respiratory insufficiency. Extracranial metastases of infratentorial ependymoma to the skin and lung are rare pathological entities.

Cerebral Ventricle Neoplasms↗
PubMed1990

[Epidural morphine as a sedative after open heart surgery: in cases of coronary artery bypass graft].

20 cases of coronary artery bypass graft (CABG) were divided randomly into 2 groups. 10 cases (Group I) received epidural catheterization between Th 6/7 at least 24 hours prior to the operation. After operation, these 10 cases were sedated with 3 mg of Morphine hydrochloride given through the epidural catheter. Other 10 cases (Group II) were sedated with 10 mg of Morphine given intravenously. Parameters of cardiorespiratory dynamics such as arterial blood pressure, pulmonary arterial pressure, pulmonary capillary wedge pressure, central venous pressure, oxygen saturation of mixed venous blood, cardiac index, doses of intravenous Nitroglycerin, Dopamine and Dobutamine, arterial blood gas analysis were measured and compared in two groups. No side effect caused by the epidural catheter was found in Group I. Parameters with significant difference in two groups were only doses of Dopamine and base excess from blood gas analysis, but these were not due to the method of sedation. Frequency of the sedation needed within 24 hours after operation was fewer, and the condition of the sedation was better in Group I. The course of postoperative management had no difference between both groups. Epidural Morphine was concluded to be an employable method of sedation after CABG.

Coronary Artery Bypass↗
PubMed1989

Effect of intracellular Na+ on platelet aggregation and Ca2+ mobilization.

The effects of ionophores, which can carry alkali metal cations, on platelet aggregation were examined. At an alkaline extracellular pH, alkali metal cation/H+ exchanger nigericin accelerated aggregation in K+-enriched medium, whereas it rather inhibited aggregation in Na+-enriched medium, even though the intracellular pH was only slightly alkaline. The inhibitory effect of Na+ on platelet aggregation was more clearly shown with the alkali metal cation exchanger gramicidin D. The ionophore had no effect or a slightly accelerative effect on aggregation in K+-enriched medium, whereas it significantly inhibited aggregation induced by thrombin, ADP and platelet activating factor in Na+-enriched medium. Fluorescence studies on fura-2-labeled platelets revealed that in Na+-enriched medium gramicidin D inhibited agonist-induced Ca2+ mobilization both in the presence and absence of extracellular Ca2+. These results suggest that the intracellular Na+ inhibits platelet aggregation by inhibiting Ca2+ mobilization.

Animals↗
PubMed1989

[Clinical and histopathological studies of the suture made of DCFF-treated natural collagen fiber].

Natural and synthetic fiber sutures used clinically, especially twist or braid type ones, will remain to the region after healing by the first intention and often cause inflammation by capillarity. It is necessary to remove those sutures from healing wounds. To obviate this necessity, we separated collagen fibers from a tendon of a rat's tail, gave them DCFF treatment for immunological tolerance, and made collagen sutures on an experimental basis. The discussion on the clinical, histopathological and physical properties of the collagen sutures proved their superiority over any other type of suture currently used. (DCFF treatment: decalcifying, defatting and freeze-drying a material previously fixed in formalin.) 1. Results of Clinical Application: Collagen sutures immersed in 70% ethanol, contacting saliva, were easily handled and fell off spontaneously in about 7 days after operation. Thus removing sutures aren't necessary. 2. Histopathological Characteristics: (1) Biopsy observations show that the collagen sutures disclosed outside of the tissues were gradually decomposed by the activity of microbes in the oral cavity, falling off spontaneously in 7-10 days by the time of healing by the first intention, whereas those inside the tissues were more slowly absorbed. (2) The major portion of the collagen sutures, implanted in the dermis of a rat's back, was decomposed and absorbed in one week or 3 months at latest, with some portion encapsulated. All nylon sutures remained without being decomposed; most silk sutures, neither easily decomposed nor encapsulated, remained and occasionally caused distinct inflammatory rejection. 3. Physical Characteristics (load and elongation test): A tensility comparison between silk sutures (4-0 U.S.P. standard) with the collagen sutures of the same thickness showed the collagen sutures were stronger than the silk ones when they are wet.

Animals↗
PubMed1988

Interhemispheric subdural haematoma complicated by intracerebral haematoma: case report.

The authors describe a case of interhemispheric subdural haematoma which was followed by an ipsilateral intracerebral haematoma after an interval of about a half day. The intracerebral haematoma is considered to be the consequence of a haematoma induced thrombosis of cortical veins in connection with a bleeding diathesis due to previous anticoagulant therapy.

Cerebral Angiography↗