Biomedical subjects
Publications and source records attributed to M Hatakenaka.
We report the MR findings in two cases of acute suppurative perithyroiditis. MR has the advantages over other imaging modalities of being able to distinguish areas of inflammation from adjacent normal tissue and of allowing imaging in planes which more accurately demonstrate the extent of the lesion. MR imaging is one of the most useful methods to evaluate this entity.
The double blind study of the effect of caffeine on the mental calculation has been carried out every year in the undergraduate course of Clinical Pharmacology, Medical School, Kyushu University. The results obtained from 1980 to 1996 are summarized and evaluated.
From January 1987 through December 1994, we performed chest wall reconstruction using the polyester mesh in 15 patients with lung cancer, 11 with empyema after open drainage, 8 with chest wall tumor and 1 with radiation dermatitis and costal chondritis. Twenty five patients were resected 3 or more ribs. Chest wall defects were reconstructed with the polyester mesh covered with Gore-Tex soft tissue patch. Twenty two cases passed more than a year without signs of infection and follow-up averaged 27.6 months. Polyester mesh was removed due to bronchial fistula (3 cases), deformities (3 cases) and abscess formation (1 case). In these cases, polyester mesh was well incorporated and had no foreign body change. In conclusion, the polyester mesh seems to be a dependable prosthetic material for chest wall reconstruction.
We studied the degranulation reaction of electropermeabilized human neutrophils induced by 1,2-didecanoyl-3-sn-phosphatidic acid (PA10). PA10 dose-dependently induced the release of beta-glucuronidase, an enzyme of azurophil granules, but did not induce the release of lactoferrin, a protein of specific granules. The enzyme release by PA10 absolutely required Ca2+, ATP, and Mg2+ and the concentrations for the half-maximal response were 2.5 microM, 60 microM, and 0.25 mM, respectively. Although Ca2+ alone at concentrations higher than 10 microM induced the release of both beta-glucuronidase and lactoferrin, the extents of the release were far less than that of the beta-glucuronidase release by PA10. Phorbol myristate acetate (PMA) and 1-oleoyl-2-acetyl-sn-glycerol induced the release of lactoferrin alone at concentrations of Ca2+ below 0.5 microM while they induced the release of both beta-glucuronidase and lactoferrin at higher Ca2+ concentrations, indicating that the degranulation induced by PA10 is not mediated by diacylglycerol which might be formed from PA. The degranulation reactions induced by PA10 and PMA were dose-dependently inhibited by staurosporine and calphostin C, protein kinase C inhibitors, although no direct activation of protein kinase C by PA10 was observed. The extent of the beta-glucuronidase release by PA10 was not enhanced by the addition of PMA. Propranolol, which inhibits protein kinase C as well as phosphatidic acid phosphohydrolase, strongly inhibited the degranulation reactions induced by PA10 and PMA. Ethanol, a metabolic modulator of phospholipase D, and cyclic AMP did not affect the degranulation reactions by PMA and PA10.(ABSTRACT TRUNCATED AT 250 WORDS)
Effect of the composition of the reaction mixture on the Ca(2+)-sensitivity of myofibrillar ATPase of rabbit skeletal muscle was investigated. The Ca(2+)-concentrations necessary for the half maximum ATPase activation were 2.95 x 10(-6) M at 50 mM KCl, 4.37 x 10(-6) M at 90 mM KCl and 5.25 x 10(-6) M at 130 mM KCl. Thus the Ca(2+)-sensitivity was definitely lower at higher KCl concentrations. The Ca(2+)-sensitivity was about 2 times higher at pH 7.3 (pCa50 5.65) compared to the Ca(2+)-sensitivity at pH 6.8 (pCa50 5.36). The change in the Mg-ATP concentration between 0.5 mM and 3.5 mM, did not significantly affect the Ca(2+)-sensitivity of myofibrillar ATPase, but affected biphasically the maximum ATPase activity. These change in the Ca(2+)-sensitivity at various conditions is considered to be due mainly to the property of troponin C, the Ca(2+)-receptive protein of myofibrils.
The effect of troponin T treatment on the Ca(2+)-activated tension of single glycerinated rabbit skeletal muscle fibers was examined. The tension of the fiber was completely desensitized to Ca2+ by incubation in a solution containing an excessive amount of troponin T and reached a level of about 70% of the maximum tension of the control fiber. SDS/PAGE showed that most of troponins C and I was removed from the fiber by troponin T treatment. During the course of troponin T treatment, the cooperativity of Ca2+ activation (Hill coefficient) was decreased while pCa at half-maximal Ca(2+)-sensitive tension (pK) increased. Using the 26-K fragment of troponin T, the study indicated that the removal of troponins C and I was due to the replacement of the troponin C.I.T complex in the myofibrils of the fiber with the added troponin T. The troponin-T-treated fiber was again sensitized to Ca2+ by the addition of troponin C.I. The removal of troponin C by treatment with trans-1,2-cyclohexanediamine-N,N,N',N'-tetraacetic acid did not change the minimum tension of the fiber, from which troponin C.I was partially removed by troponin T treatment, but it decreased the height of maximum tension with a concomitant decrease in the Hill coefficient as well as a decrease in pK. The above findings suggested that pK is determined by the balance between two opposite actions through troponins C and I, while the extent of cooperativity of Ca2+ activation seemed to be related mainly to the content of troponin C.
The tension of single glycerinated rabbit skeletal muscle fiber was desensitized to a Ca(2+)-concentration after treatment with an excessive amount of bovine cardiac troponin T and reached a level of about 70% of the maximum tension of the untreated fiber. A SDS-gel electrophoretic examination indicated that troponin C.I.T complex in the fiber was replaced with the added cardiac troponin T. The Ca(2+)-sensitivity of the tension of the troponin T-treated fiber was then recovered by the addition of bovine cardiac troponins I and C. The rabbit skeletal muscle fiber thus hybridized with bovine cardiac troponin C.I.T showed the same cooperativity of Ca(2+)-activation as the cardiac muscle.
We have developed a finger-piece method that can indicates an accurate concentration of ICG based on the two wavelength spectrophotometry. Seventy-eight subjects were evaluated by this new method. The ICG clearance curve obtained from ICG clearance meter showed a rapid increase 20 or 40 seconds after the bolus injection. The curve decreased gradually, and increased again at 60 or 70 seconds. Plasma disappearance rate (PDR) by this method (XK ICG) was calculated by the at least square method from 600 data obtained from 5 to 15 minutes after the injection. There was a significant correlation between conventional PDR (KICG) and new method (XK ICG) also. We assume that this method have a possibility to discover new aspect of pharmacokinetics of ICG.
The application of immunocytochemistry in urinary cytology for the identification of a human polyomavirus infection is described. The Papanicolaoustained slides of voided urine specimens of a 26-year-old man undergoing steroid therapy showed many inclusion-bearing epithelial cells. After subsequent destaining of the same slides, the presence of human papovavirus antigen in the nuclei of infected exfoliated cells was demonstrated by immunocytochemical staining with simian virus 40 antiserum and peroxidase. Papovaviruses were also detected by electron microscopic study of the smears, confirming the diagnosis of a human polyomavirus infection. The use of immunoperoxidase studies proved to be advantageous for the rapid cytodiagnosis of human polyomavirus infection in the urinary specimens in this case; such studies may be of particular value in equivocal cases to prove or disprove the viral nature of morphologic changes observed in routine preparations.