Biomedical subjects
Publications and source records attributed to S Uchida.
The authors report 6 patients (7 joints) in whom inflammation, dermal necrosis, dermatitis or fistula formation was attributed to the materials commonly used for joint endoprostheses. Histological appearances and chemical analyses of the involved tissues are presented, together with a discussion of the possible mechanism and methods of diagnosis and treatment.
A newly designed stable total knee prosthesis was made for the severely destructed knee. This prosthesis was named the Yoshino total knee prosthesis, and is a non-hinged type prosthesis consisting of a vitallium femoral component and a ultra-high molecular weight polyethylene tibial component. Clinical results of 127 Yoshino total knee arthroplasties showed the following characteristics: 1) good stability, and 2) good mobility. Stability was exceptionally good, and the results were the same as the hinged total knee prosthesis.
A light-activated GTPase that functions as a component of the rhodopsin-linked, light-activated phosphodiesterase (PDEase) system in vertebrate photoreceptors has been reported. In our efforts to purify photoreceptor GTPase we encountered another component (which we call "helper" or "H" component) whose presence is required for expression of light-activated GTPase activity. We report here the characterization of this heat-labile, macromolecular factor and that the presence of helper is absolutely required for light- and rhodopsin-dependent activation of photoreceptor GTPase. Of equal importance, we find that the "G" component (which requires the presence of H for expression of GTPase activity) can bind GTP and can support light- and GTP-dependent PDEase activation in the absence of H component. These data support a model in which GTP binding to G component is a necessary condition for PDEase activation. Hydrolysis of GTP at the G activator locus (an H-dependent activity) is a regulatory event which reverses PDEase activation. The complexity of this regulatory mechanism provides opportunities for signal modulation and amplification.
DNA prepared from cell lines and transplanted tumors originating from five representative types of BKV-induced hamster tumors was examined for the presence of the BKV genome by analyzing DNA/DNA reassociation kinetics. BKV DNA sequences were detected in all cases. There were only a few (1--4) copies of BKV DNA per cell in one osteosarcoma and two ventricular tumors (one choroid plexus papilloma and one ependymoma), but there were multiple (up to 150) copies in one osteosarcoma, one ventricular tumor (choroid plexus papilloma), two insulinomas, one pineocytoma, and one cerebral neuroblastoma. In some cases the number of copies of the viral DNA differed among sister cell clones derived from the same primary tumor. Apparently some tumors contained nonintegrated free viral DNA besides the integrated BKV genome.
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A new anthramycin-group antitumor antibiotic, neothramycin, isolated from a Streptomyces culture, showed activity against experimental tumors such as lymphocytic leukemia P388 ascites sarcoma-180, hepatoma AH130, Walker carcinosarcoma-256 and mouse mammary adenocarcinoma (CCMT). In particular, the tumor growth inhibition ratio was as high as 96% when neothramycin was injected intraperitoneally at a daily dose of 2 mg/kg into Wistar strain rats previously inoculated with Walker carcinosarcoma-256 by the subcutaneous route. Successive intraperitoneal injections of the compound were more effective than a single injection with the P388 system.
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This is the first case of two siblings with congenital dyserythrobpoietic anemia (CDA) type I to be reported from a Japanese family. Both of these cases showed characteristic morphological aberration of erythroid precursors, ineffective erythropoiesis, and negative acidified serum test. The ultrastructural study of erythroblasts also revealed characteristics quite compatible with CDA type I.
A plaque morphology mutant (pm-522) of human papovavirus BK, which was rescued from a human papovavirus BK-induced hamster pineocytoma, was characterized and compared with a cloned wild-type virus (wt-501). Mutant pm-522 formed turbid plaques and grew more slowly than wt-501 in human embryonic kidney (HEK) cells. The immunofluorescence assay revealed that more HEK cells underwent abortive infection with pm-522 than with wt-501. Whereas wt-501 induced brain tumors and osteosarcomas, but no insulinomas, in hamsters, pm-522 induced brain tumors and insulinomas. The DNA of pm-522 was found by electrophoresis and electron microscopy to have a deletion (85 +/- 15 base pairs) and an insertion (40 +/- 10 base pairs) between map coordinates 0.708 and 0.725 from the endonuclease EcoRI cleavage site. These results demonstrate the presence of a viable deletion human papovarivus BK mutant capable of inducing insulinomas in hamsters.
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Newborn hamsters were inoculated intracerebrally with a series of purified and concentrated BK virus samples originating from a single stock of Gardner's original strain. Most (60-100%) of the hamsters developed various tumors 3-9 months later. The frequent types of tumors were ventricular tumors (choroid plexus papillomas and ependymomas: 7-53%), malignant insulinomas (0-92%), and osteosarcomas (0-50%). The T-antigen was positive in 59 of 60 tumors tested, but the virus was rescued by the cell fusion method from only 1 of 11 cell lines derived from these tumors. The incidence of insulinomas varied greatly with the virus sample; the two samples that showed the highest incidence (47 and 92%) originated from one parental virus stock, and all the other samples with the lower incidences (0-9%) originated from another ancestral stock. These results suggest the presence of a BK virus mutant(s) differing in capacity to induce insulinoma. A functional insulinoma cell line was thus established.
2-Chloro-11-(2-dimethyl-aminoethoxy)dibenzo [b,f]thiepine (zotepine) is a new neuroleptic drug with a chemical structure different from known neuroleptics. The psychopharmacological effects of zotepine in mice, rats and dogs were studied and compared with those of commercially available neuroleptics. Haloperidol and perphenazine were the most active and thioridazine was the least active in hibiting apomorphine-induced gnawing and circling movement, methamphetamine-induced gnawing and circling movement, conditioned avoidance response, motor activity, dopamine-induced pancreatic secretion and apomorphine-induced vomiting. These drugs also had the same order of potency in inducing catalepsy and increasing dopamine turnover and prolactin release. Chlorpromazine, propericiazine and thiothixene were intermediate in potency. Zotepine equalled chlorpromazine in most activities, however, it was clearly less active than chlorpromazine in potentiation of barbiturate sleep and cardiovascular effect.
Two forms of enzyme with ribonuclease H (RNase H) [EC 3.1.4.34] activities, have been partially purified from cultured plant cells, strain GD-2, derived from carrot root. One is an Mn2+-dependent RNase H, and the second is an Mg2+-dependent RNase H. These enzymes degrade RNA specifically in RNA-DNA hybrid structures. They were eluted at around 0.2 M and 0.4 M potassium chloride in phosphocellulose chromatography, and were further purified using blue Sepharose. Mg2+-dependent RNase H exhibits maximal activity at pH 9.0, and requires 10 to 15 mM Mg2+ for maximal activity, whereas the Mn2+-dependent enzyme is most active at pH 8.0, is maximally active at an Mn2+ concentration of 0.4 mM, and has some activity with Mg2+. Both enzymes require a sulfhydryl reagent for maximal activity. The enzymes liberate a mixture of oligonucleotides with 5'-phosphate and 3'-hydroxyl termini. The apparent molecular weight of the Mg2+-dependent RNase H was estimated to 18--20 X 10(4) and that of the Mn 2+- dependent RNase H was estimated to be 14 x 10(4) by gel filtration.
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