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Biomedical subjects

T Nishihara

Publications and source records attributed to T Nishihara.

At least 289 records · Page 16Linked to original sources

Serodiagnosis of type A hepatitis by detection of immunoglobulin M-type antibody to hepatitis A virus.

Serum specimens from 12 patients with type A hepatitis were analyzed for immunoglobulin M-type antibody to hepatitis A virus (IgM anti-HA). A recently developed solid-phase radioimmunoassay kit for IgM anti-HA (HAVAB-M, Abbott Laboratories) and a competitive binding radioimmunoassay kit (HAVAB, Abbott Laboratories) with or without 2-mercaptoethanol treatment, as modified by Yano et al. (Acta Hepatol. Jpn. 21, 704-712, 1980) were used to obtain an M-index. All specimens obtained within 60 days of the onset of illness and specimens from 2 of 4 patients later than 60 days after the onset were positive with the HAVAB-M test. This test gave negative results to sera which were positive for anti-HA by a standard HAVAB test in the following: 3 patients with type B hepatitis; 5 with non-A, non-B hepatitis; 11 healthy adults; and 10 sera strongly positive for rheumatoid factor. The M-index for type A hepatitis in sera within 30 days of the onset (mean value of the M-index, m, = 1.52; standard deviation, SD, = 0.25) was significantly higher than that for non-A hepatitis (m = 1.05; SD = 0.15) and for healthy adults (m = 1.02; SD = 0.10). The simplicity and usefulness of the HAVAB-M test in diagnosis of acute type A hepatitis over those measuring the M-index by HAVAB tests were shown by direct comparison of the results.

Adult↗

Nephrotoxic nephritis in nude mice.

We investigated the role of T cells in the pathogenesis of murine nephrotoxic nephritis (NTN). The disease was produced by injecting congenitally athymic nude (nu/nu) mice and their normal heterozygous (nu/+) littermates with rabbit anti-rat glomerular basement membrane (GBM) antiserum. Within 2-4 weeks we noted marked thrombotic lesions and depositions of mouse IgG, IgM, C3 and rabbit IgG along the GBM in both groups of mice. There was no significant difference in the extent of glomerular involvement between the two groups of mice. We conclude that T cell immunodeficiency plays no role in the development of severe glomerular lesions in murine NTN.

Animals↗

Studies on protease from marine bacteria. 1 Isolation of marine Pseudomonas sp 145-2 and purification of protease.

Marine Pseudomonas strain 145-2 having the ability to produce extracellular protease was isolated from Uwa sea water, Ehime prefecture in Japan. This strain grows at 0 degrees - 37 degrees C, but protease production was observed only during 6-10 h cultivation at 20 degrees - 30 degrees C, when casein, as the nitrogen and carbon source in a concentration of 0.5-1.0%, was used. Maximum production of protease by the strain was also observed. Na, K, Ca and Mg ions were needed for growth and production of protease. Two extracellular proteases (proteases I and II) were purified from the culture supernatant by ammonium sulphate fractionation following Sephadex gel chromatography. Protease I had a larger molecular weight than protease II. After purification, proteases I and II were revealed as homogeneous by acrylamide gel electrophoresis and immunoelectrophoresis.

Amino Acids↗

Modification of cytidines in a Q beta replicase template: analysis of conformation and localization of lethal nucleotide substitutions.

The solution conformation of MDV-1( + ) RNA, a small RNA template replicated autocatalytically in vitro by Q beta replicase, was investigated with sodium bisulfite, a reagent that selectively converts single-stranded cytidines to uridines. The reactivity of 45 of the 76 cytidines in MDV-1( + ) RNA was determined by nucleotide sequence analysis. Only 14 of these 45 cytidines were converted to uridine. Treatment of the RNA with methoxyamine, another single-strand-specific cytidine modification reagent, gave results in good agreement with the bisulfite data. The limited reactivity of MDV-1 ( + ) RNA with these reagents indicates that it is a highly structured molecule. A secondary structure consistent with the chemical modification data is proposed. Modification of MDV-1 ( + ) RNA by bisulfite renders it inactive as a template for RNA replication. This inactivation and the modification of the cytidines at the 3' end of the molecule occur at very similar rates. By using a short complementary RNA "mask" to protect just these cytidines, we demonstrated that the loss of activity resulted from their modification. This implies that one or more of the cytidines in the 3'-terminal sequence is required for template activity and that changes within this sequence can have lethal consequences. The effects of modification elsewhere in the sequence are discussed.

Base Sequence↗

Studies on the bacterial spore coat. (7) Properties of alkali-soluble components from spore coat of Bacillus megaterium.

Properties of alkali-soluble components from the spore coat of Bacillus megaterium were examined by physicochemical methods. They were composed of acidic polypeptides of various molecular weights with small amounts of phosphorus and sugar. They were allowed to dissociate to unit components by incubation with SDS. The major component was partially purified by gel filtration, and shown to have a mean molecular weight of about 11,000.

Bacillus megaterium↗

Location of elements in ashed spores of Bacillus megaterium.

The structure of the skeleton of spores of Bacillus megaterium was examined after ashing in a plasma asher and the elemental composition of the ashed whole spores was determined with an analytical electron microscope. All spores were ashed in situ although they shrank by about 15%. Even P and S, in addition to metals, were recovered well from ashed samples. Ash was rich in the core and the coat, and poor in the cortex. Ca, P, S, and Mg were detected in the core and coat of the spore of B. megaterium QM B1551. Ca in the core was markedly decreased by germination or autoclaving. In the spore of B. megaterium ATCC 19213, almost all of the ash was detected in the core and its elemental composition was similar to that of the core of the strain QM B1551 spore. These reuslts suggest strongly that the core is the site of Ca associated with dipicolinic acid.

Bacillus megaterium↗

Growth and sporulation of auxotrophs of Bacillus subtilis in a medium with limited nutrients.

Growth and sporulation were examined for 30 auxotrophs of Bacillus subtilis in a chemically defined medium with suboptimal amounts of nutrients. All strains except for some adenine-requiring mutants could not overtake sporulation stage II when amino acids, vitamins, or bases were limited, whereas they sporulated fairly well without limitation. Abnormal structures, a cell with thickened cell wall and a cell with several refractile bodies, were found in some strains after the vegetative growth stopped.

Adenine↗

[Automatic rearing system of mice and transmission of pseudomonas aeruginosa].

Mice either excreting or not excreting Pseudomonas aeruginosa in feces were maintained in stainless steel mesh cages on an automated rearing apparatus with automatic water-supply nozzles and intermittently flusing metal racks. No evidence of transmission of the organisms from positive mice to negative ones was obtained during at least eight weeks.

Animals↗

Meralgia paresthetica: electrophysiologic study.

Conduction velocity of the lateral femoral cutaneous nerve was studied orthodromically. The mean value in 20 control subjects was 57.51 +/- 8.61 (SD) m/sec. In 9 patients with meralgia paresthetica, the sensory nerve condition in the symptomatic nerves was definitely abnormal: nerve potential was absent in 6 and condition velocity was slow in 3. In 1 patient, a possible asymptomatic entrapment neuropathy was suggested by this test. Conduction velocity of the lateral femoral cutaneous nerve can be used as an objective diagnostic aid in meralgia paresthetica.

Adult↗

[Three cases of hemolytic Streptococcus infection in guinea-pigs (author's transl)].

Three cases of naturally occurring hemolytic streptococcus infection were detected in guinea-pigs which had been delivered from different sources to the Division of Animal Research, Faculty of Medicine, University of Tokyo, Tokyo, during the period from November, 1976, till February, 1977. The clinical manifestations of the infection were differentiated into two types; ie, the acute type with sepsis and pneumonia as main pathologic changes, and the chronic type with abscess formation of submaxillary lymph node. Streptococcus zooepidemicus was isolated from the conjunctiva of about 56% of these guinea-pigs. Healthy guinea-pigs housed with spontaneously infected ones in the same cage suffered from the infection, showing manifestation and pathologic changes similar to the spontaneous cases. Some of them, however, remained apparently healthy for about 2 months harboring the organisms in the conjunctiva or nasal cavity. It is presumed that such carriers become a source of the infection in nature.

Animals↗

[Maintenance of mice in automatic rearing system. I. Rearing tests with ICR mice (author's transl)].

Female ICR:JCL mice were reared in wire-mesh cages with nozzles for automatic water supply on a battery with an automatic washing system, and the evaluation of this system was made in comparison with the conventional feeding system with water bottles, alumite cages and changes of the bedding. In weight gains, feed intakes, water consumption, leucocyte and erythrocyte counts, hematocrit values or vaious organ weights during the period from 3 to 14 weeks of age, animals maintained by the automatic rearing system showed no significant difference as compared with those maintained by the conventional system, providing evidence for a conspicuous labor saving with the automatic control system.

Animals↗