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Biomedical subjects

M Ohta

Publications and source records attributed to M Ohta.

At least 1,189 records · Page 66Linked to original sources
PubMed1983

Adjuvant activity of Klebsiella O3 lipopolysaccharide: no contribution of proteins to the expression of adjuvant activity.

Previously we found that Klebsiella O3 lipopolysaccharide (KO3 LPS) isolated from culture supernatant of strain Kasuya (O3: K1) or its decapsulated mutant strain LEN-1 (O3: K1-) exhibited very strong adjuvant activity in augmenting antibody response and delayed-type hypersensitivity to protein antigens in mice. The preparation of KO3 LPS after deproteinization by four cycles of treatment with chloroform-butanol (5: 1) usually contained a small percentage of proteins and a definite amount of another antigen which was destroyed by heating at 100 C for 1 hr. This antigen proved to be derived from type 1 fimbriae which are responsible for mannose-sensitive hemagglutination of guinea pig erythrocytes. The preparation of KO3 LPS isolated from culture supernatant of the strains which did not produce type 1 fimbriae exhibited strong adjuvant activity similar to that of the preparation from those which produced them. The preparation of KO3 LPS treated with hot phenol water which is known to remove lipid A-associated proteins exhibited a similar strong adjuvant activity. The preparation of KO3 LPS after extensive deproteinizing, two cycles of pronase treatment followed by ten cycles of treatment with chloroform-butanol, no longer contained detectable amounts of proteins and the fimbrial antigen, but this preparation also exhibited similar strong adjuvant activity. Moreover, there was no difference in strength of the adjuvant activity between the preparation of KO3 LPS isolated from culture supernatant and that isolated by the phenol method from bacterial cells. The present study demonstrates that the strong adjuvant activity of the preparation of KO3 LPS does not depend in any way on proteins contaminating the preparation.

Adjuvants, Immunologic↗
PubMed1983

Virulence for mice of Klebsiella strains belonging to the O1 group: relationship to their capsular (K) types.

Eighty-two Klebsiella O1 strains belonging to various K types were tested for virulence for mice by intraperitoneal inoculation. They comprised 49 strains newly isolated from various clinical specimens, 31 reference strains, and 2 laboratory strains. Of 9 Klebsiella O1:K2 strains, 7 were highly virulent inasmuch as their 50% lethal doses per mouse were less than 10 CFU, whereas the other 2 strains were avirulent even when encapsulated just like the virulent strains as revealed by the quellung test. Klebsiella K2 reference strain B5055 and strain Chedid, which were maintained in vitro for a long time, were highly virulent. Of 8 Klebsiella O1:K1 strains, 2 showed moderate virulence, and the other 6 strains had relatively low or no virulence. We found no definite correlation between the virulence of Klebsiella K1 and K2 strains for mice and the kind of clinical specimens in which they originated. All of the Klebsiella O1 strains tested belonging to K types other than K1 and K2 showed very low or no virulence for mice.

Animals↗
PubMed1983

Joseph disease in a non-Portuguese family.

We studied four patients with Joseph disease in a Japanese family. There were two clinical types in the family. One was characterized by pyramidal and cerebellar signs with or without extrapyramidal signs; the other, by cerebellar signs, loss of tendon reflexes, and peripheral sensory loss. The family tree indicated autosomal-dominant inheritance. Neuropathologic examination revealed marked degeneration of the substantia nigra, dentate nuclei, Clarke column, and anterior horn cells of the spinal cord. This is the first report of pathologically proven Joseph disease in a non-Portuguese family.

Adult↗
PubMed1983

Blockage of ovulation in the explanted hamster ovary by a collagenase inhibitor.

Hamster ovaries explanted at 21:00 h on the day of pro-oestrus were incubated with talopeptin, a potent microbial inhibitor of collagenases, until 10:30 h on the next morning. A talopeptin concentration of 0.16 mM completely blocked ovulation in vitro. The blocking effect decreased markedly in ovaries excised at 23:00 h or later. The results suggest that proteolysis by collagenases is indispensable for the ovulatory process in the hamster.

Animals↗
PubMed1983

Effect of various proteinase inhibitors on ovulation of explanted hamster ovaries.

Hamster ovaries explanted at 21:00-24:00 h on the day of pro-oestrus were incubated with microbial proteinase inhibitors until 10:30 h on the next morning and the ovulatory blocking effect of these inhibitors was examined. Amongst 11 proteinase inhibitors examined, talopeptin, a specific inhibitor for metallo-proteinases, and alpha-MAPI, a specific inhibitor for serine and thiol proteinases, were the strongest blockers. These 2 inhibitors exhibited a chronological discrepancy in their blocking effect on ovulation. S-SI, plasminostreptin, elastatinal, antipain and chymostatin, which are inhibitors for serine proteinases, partly but significantly inhibited ovulation. The results suggest that, in addition to a metallo-proteinase reported previously, a proteinase which is sensitive to alpha-MAPI is essential for the ovulatory process, and that serine proteinase(s) also participate in ovulation of the hamster ovary.

Animals↗
PubMed1983

The relationship between diabetes mellitus and coronary heart disease.

The present study was aimed at investigating the relationship between diabetes and coronary heart disease. 100 g oral glucose tolerance test was performed on 32 well-defined male non-obese patients with coronary heart disease (myocardial infarction and angina pectoris, 16 patients each; average age 47.5 years) and 12 non-obese controls (average age 46.2 years). The results were as follows: 1) Glucose tolerance was impaired in 19 of 32 patients. 2) Insulin response to glucose in patients with normal glucose tolerance was similar to that in controls, while insulin response in patients with impaired glucose tolerance showed a delayed peak. 3) The insulinogenic index of patients with normal glucose tolerance was the same as that of controls, while the insulinogenic index of patients with impaired glucose tolerance was lower, and 4) overnight fast serum cholesterol and triglycerides in patients with normal glucose tolerance showed similar levels to those in controls, but were elevated in patients with impaired glucose tolerance. These results suggest that impaired glucose tolerance observed in patients with coronary heart disease may result in part from "latent diabetes."

Adult↗
PubMed1983

[Effect of adjuvant immunotherapy with Nocardia rubra cell-wall skeleton in lung cancer].

A randomized clinical trial of intrapleural Nocardia rubra cell-wall skeleton (N-CWS) followed by intradermal N-CWS was performed against lung cancer patients from November, 1977 to June 1981. Totally, 190 patients were entered into this trial. The N-CWS treatment was effective in terms of prolongation of remission duration against not only operable but also inoperable patients. However, significant improvement of survival rate was observed only in operable patients, especially curative+relatively curative resection-group (p less than 0.05). The mode of recurrence was classified as local recurrence and distant metastasis in the curative+relatively curative resection-group. The rates of distant metastasis were 34.1 and 17.6%, respectively, in the control and the N-CWS groups. The rate of local recurrence was 13.6% in the control group, however, no local recurrence was observed in the C-NWS group. These results indicate the clinical effectiveness of the N-CWS treatment especially in curatively resectable lung cancer. No serious side effect was experienced during this trial.

Adenocarcinoma↗
PubMed1983

The development of dental alloys conserving precious metals: improving corrosion resistance by controlled ageing.

To determine the conditions which confer desirable mechanical properties and corrosion resistance upon dental alloys, age-hardening mechanism and the associated structural changes were studied by means of resistometric measurements, hardness tests, electron microscope observations and electron diffraction studies. Five commercial dental alloys, a high-gold content alloy, a low-gold alloy and three Au-Ag-Pd silver-based alloys and two experimental gold alloys, were examined. The structural and morphological changes which gave rise to age-hardening were classified into five types of phase transformation, i.e., (1) the formation of the AuCu I type superlattice and its twinning characterized by a stair-step mode, (2) the formation of the AuCu II type super-lattice with periodic antiphase domain structure, (3) the precipitation of the CuPd superlattice with fct structure analogous to the AuCu I type, (4) spinodal decomposition giving rise to a modulated structure and (5) the formation of the lamellar structure developed from grain boundaries by discontinuous precipitations. (1), (2) and (3) made a contribution to corrosion resistance superior to (4) and (5). A lamellar structure was prone to a high corrosion rate. The results obtained in this study are useful in predicting age-hardening characteristics and structural changes associated with corrosion, because the microstructural variation induced by ageing as well as nobility of alloys affects greatly their corrosion resistance.

Chemical Phenomena↗