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Biomedical subjects

Y Nishimura

Publications and source records attributed to Y Nishimura.

At least 1,117 records · Page 62Linked to original sources
PubMed1983

Escherichia coli uvrD mutants with thermosensitive DNA-dependent adenosine triphosphatase I (helicase II).

Three mutants producing thermosensitive DNA-dependent Adenosine triphosphatase (ATPase) I were screened from a collection of temperature-sensitive mutants of Escherichia coli K12. ATPase I purified to near homogeneity from one of the mutants (JE11000) possesses both thermosensitive DNA-dependent ATPase and DNA helicase activities. We have shown that ATPase I is encoded by the uvrD gene as first suggested by Oeda et al. (1982): (i) the thermosensitive ATPase I mutation present in JE11040 lies in or very close to the uvrD gene, (ii) ATPase I activity is absent in uvrD210, uvrD156, and uvrD252 mutants. Thus the thermosensitive mutations correspond to new uvrD mutations. However, the mutation present in JE11040 confers neither UV sensitivity nor mutator phenotype at high temperature. Evidence is presented that the mutant ATPase I is stabilized in vivo at 42 degrees C.

Adenosine Triphosphatases↗
PubMed1983

Serologic dissection of HLA-D specificities by the use of monoclonal antibodies.

To study the gene products of the HLA complex, we produced two monoclonal antibodies, termed HU-18 and HU-23. They were active in complement-dependent cytotoxicity and detected B-cell alloantigens encoded by a locus (or loci) linked to HLA. When three types of HLA-DR4 homozygous B-cell lines with different HLA-D specificities were tested for reactivity with HU-18 and HU-23, they displayed distinct reaction patterns depending on the HLA-D specificities they possessed: EBV-Wa (HLA-DYT homozygous), negative for both HU-18 and HU-23; KT2 and KOB (HLA-DKT2 homozygous), positive only for HU-18; and ER (HLA-Dw4 homozygous), positive for both. These differential reaction patterns were further confirmed by testing against a panel of 17 HLA-DR4-positive peripheral blood lymphocytes with known HLA-D specificities. Thus, these monoclonal antibodies allow us to identify HLA-DYT, HLA-DKT2, and HLA-Dw4 solely by serologic methods. This is the first clearcut serologic identification of these three HLA-DR4-associated HLA-D specificities, which have been indistinguishable by conventional serology and identified only by cellular techniques. It is hoped that immunochemical investigations using HU-18 and HU-23 will advance our understanding of the HLA-D region on a molecular level.

Antibodies, Monoclonal↗
PubMed1983

Effects of a heat-labile factor(s) in normal serum on the interferon-inducing activity of Newcastle disease virus (NDV). Brief report.

The effect of fresh serum on the interferon-inducing activity of Newcastle disease virus (NDV) was studied. Infectivity in fertile eggs, hemolytic activity in human erythrocytes and interferon-inducing activity in mouse L cells and mouse spleen cells were all reduced by treatment of NDV with fresh serum from humans or guinea pigs, while hemagglutinating (HA) activity remained unchanged. The interferon-inducing ability of UV-inactivated NDV was also similarly reduced after treatment with serum. The serum effects were decreased by heating at 56 degrees C for 30 minutes or the addition of 10 mM EDTA. These results suggest that a heat-labile serum factor(s) such as complement or certain enzyme(s) reduced the hemolytic activity and consequently the penetrating activity of NDV, and that interferon-inducing activity was related to the hemolytic but not to the HA activity of NDV particles. Thus, it was concluded that the hemolytic activity of NDV was necessary for interferon induction in both mouse L cells and mouse spleen cells.

Animals↗
PubMed1983

Dynamics of DNA in chromatin and DNA binding mode to core protein.

We have studied the dynamics of DNA in nucleosome core particles and in the linker region of chromatin using nanosecond fluorescence anisotropy decay measurements of intercalated ethidium. DNA in the core undergoes torsional motions to the same extent as the linker DNA in extended chromatin. We therefore concluded that the binding of DNA to the histone octamer is relatively weak or limited to a few points; stretches of at least several tens of base pairs exist which can move as freely as DNA in solution.

Animals↗
PubMed1983

Bilateral oblique facial cleft.

An extremely rare case of bilateral oblique facial cleft is presented. This should be classified as a bilateral oroocular Type I cleft according to Boo-Chai's classification and a bilateral No. 4 cleft according to Tessier's classification. Except for this deformity, the patient was normal and healthy. Corrective surgical procedures were carried out between the ages of 4 months and 18 months to repair the left and right clefts, remove an abscess caused by the remnant of the lacrimal canal, and repair the cleft palate. The patient is now making a good recovery. Bone graftings or craniofacial osteotomies may be recommended at a later age.

Cleft Lip↗
PubMed1983

Immunohistochemical localization of 2',3'-cyclic nucleotide 3'-phosphodiesterase and myelin basic protein in the chick retina.

Antisera against bovine 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) and against chick myelin basic protein (MBP) were raised in New Zealand white rabbits. The specificity of CNPase antiserum was examined by Ouchterlony double-immunodiffusion test and immunoadsorption assay. With use of the specific antiserum, immunohistochemical localizations of CNPase and MBP were investigated in the chick retina. Light microscopic immunohistochemical studies have shown that MBP is localized in the optic nerve fiber layer and that CNPase is localized in the optic nerve fiber and photoreceptor layers. Electron microscopic immunohistochemical examinations demonstrated that the myelin-like neural sheaths in the optic nerve fiber layer were clearly stained by both antisera, whereas the membranes of the Müller cell were not stained. In the photoreceptor layer, membranes of the inner and outer segments of rod and cone photoreceptor cells were intensely stained by CNPase antiserum. However, these portions were not stained by MBP antiserum. Membranes of bipolar cells, amacrine cells, horizontal cells, and ganglion cells were not stained by either antiserum.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1983

[Double-blind comparative clinical study of cefpiramide (SM-1652) and cefsulodin on complicated urinary tract infections due to P. aeruginosa].

The therapeutic efficacy and safety of Cefpiramide (CPM, SM-1652) at a 2 g/day dose were objectively compared with those of Cefsulodin (CFS) at a 2 g/day dose in patients with chronic complicated urinary tract infections (UTI) by P. aeruginosa in a double-blind study at 46 institutions in Japan. The results are as follows: The therapeutic efficacy was analyzed in 254 patients (136 cases administered CPM and 118 cases administered CFS) after excluding 20 cases as drop-out. Among 254 cases, the number of patients with infection of P. aeruginosa was 190 cases (100 cases administered CPM and 90 cases administered CFS), while that with infection of organisms other than P. aeruginosa was 64 cases (36 cases administered CPM and 28 cases administered CFS). By the administration of a 2 g/day dose for 5 days, the overall clinical effective rate of CPM was significantly higher than that of CFS in total patients. When the patients were classified into 2 groups with respect to causative organisms (P. aeruginosa and others), the clinical effective rate of CPM in patients with infections of P. aeruginosa was significantly higher than that of CFS, while the clinical effective rate of CPM in patients with infection of other organisms than P. aeruginosa was the same as that of CFS. As to the bacteriological effect on bacteriuria, the eradication rate of CPM was significantly higher than that of CFS not only against all causative organisms but also against P. aeruginosa. The rate of replacement by S. faecalis was significantly higher in the CFS-treated group than in the CPM-treated group. The same result was obtained on the rate of replacement by other organisms. The MIC values of CPM for isolated organisms before drug administration were lower than those of CFS. The incidence rates of side effects and the abnormal findings of clinical laboratory tests were the same for the CPM- and CFS-treated groups. From the results, it was concluded that CPM is a useful drug for the treatment of patients with chronic complicated urinary tract infections caused by P. aeruginosa.

Adult↗
PubMed1983

Lactate dehydrogenase A-subunit and B-subunit deficiencies: comparison of the physiological roles of LDH isozymes.

Different clinical features exist for lactate dehydrogenase A-subunit and B-subunit deficiencies. The metabolic basis for these clinical differences was elucidated by investigating carbohydrate metabolism in the affected tissues. Glycolysis was markedly retarded at the position of glyceraldehyde 3-phosphate dehydrogenase, and significant increases of glyceraldehyde 3-phosphate, dihydroxyacetone phosphate, and fructose 1,6-diphosphate were observed. The physical and kinetic properties of glyceraldehyde 3-phosphate dehydrogenase prepared from human erythrocytes and skeletal muscle were almost identical, but the mode of inhibition of the enzyme was slightly different in erythrocytes and in skeletal muscle. In erythrocytes, impaired reoxidation of NADH followed by the deficiency of substrate NAD+ causes a reduction of glyceraldehyde 3-phosphate dehydrogenase activity. However, in skeletal muscle, the increased level of NADH markedly inhibits the enzyme under anaerobic conditions. A flux of triose phosphates from glycolysis occurred in skeletal muscle of a patient with A-subunit deficiency. This flux is attributable to the high cytosol alpha-glycerophosphate dehydrogenase activity in skeletal muscle. for these reasons the ATP production was significantly impaired in the patient and the damage to muscle cells brings about the release of cytosolic enzymes and muscle rigidity after hard exercise. In contrast in the erythrocytes, the level of alpha-glycerophosphate dehydrogenase is very low and another red cell-specific NADH reoxidizing system such as NADH-cytochrome b5 reductase (NADH-methemoglobin reductase) is operating. In this manner, the NAD+ level in erythrocytes is compensated for without the flux of triose phosphates derived from glucose. Therefore, the ATP production in erythrocytes is sufficiently maintained by glycolysis even in a patient with complete lactate dehydrogenase B-subunit deficiency. Thus, impaired ATP production in anaerobic stage is a condition which is specific for lactate dehydrogenase A-subunit deficiency but does not occur for B-subunit deficiency. The different clinical features of the A- and B-subunit deficiencies have been clearly elucidated.

Erythrocytes↗