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Biomedical subjects

M Oka

Publications and source records attributed to M Oka.

At least 703 records · Page 39Linked to original sources
PubMed1983

Effects of cholera toxin on the lymphoid system. III. In vivo generation of cytotoxic lymphocytes.

Cytotoxic T lymphocytes (CTL) were generated in the spleen by subcutaneous inoculation of EL-4 leukaemia cells (H-2b) into C3H/He mice (H-2k). (1) Cytotoxicity of spleen cells was profoundly suppressed by an intravenous injection of 1 microgram cholera toxin on the day of tumor inoculation. Tumors continued to grow progressively. (2) Differentiation of memory cells to mature CTL was suppressed by cholera toxin injection on the day of booster inoculation of EL-4 cells. The tumors grew progressively in immune mice given cholera toxin on the day of the booster. (3) In vitro treatment of CTL with cholera toxin suppressed the expression of their cytotoxic activity to a considerable extent. However, tumors regressed very rapidly after rechallenge to immune mice carrying CTL, even when cholera toxin was injected on the day of rechallenge. Cholera toxin suppressed not only the functional expression of CTL but also the induction phase of CTL generation.

Animals↗
PubMed1983

Malignant degeneration of benign cystic teratoma of the bilateral ovaries: adenosquamous carcinoma in the right tumor and squamous carcinoma in the left tumor.

An extremely rare case of malignant degeneration arising separately in benign cystic teratoma of the bilateral ovaries is reported in a 51-year-old woman. The solid part of the right tumour consisted basically of squamous cell carcinoma, but had a small area of adenocarcinoma, whereas the solid part of the left tumour consisted of squamous cell carcinoma. It was found that in both the cystic teratomas, squamous cell carcinoma had developed separately from the columnar epithelium by a process of squamous metaplasia and malignant change in situ. It is suggested that these malignant degenerations of benign cystic teratoma of the bilateral ovaries had occurred independently due to local carcinogenic agents in the constituents of each cyst content.

Adenocarcinoma↗
PubMed1983

Augmented delayed footpad reaction in thymus cell-depleted mice induced by cholera toxoid.

One hundred microgram of cholera toxoid was injected intravenously into DDD and AKR mice and its effects on lymphoid tissues and immune responses against sheep erythrocytes (SRBC) were examined at various times after the injection. (1) A remarkable reduction of thymus cells was revealed from day 1 to 7 and from day 1 to 4 in DDD and AKR mice, respectively. (2) Cholera toxoid exhibited only slight effects on the numbers of spleen cells and peripheral blood leukocytes in both strains. (3) Delayed footpad reactions to SRBC were augmented by a pretreatment with cholera toxoid 4 or 7 days before immunization in both strains. The delayed reactions were not suppressed in the presence of a prominent antibody production and were accompanied by positive macrophage migration inhibition. (4) Antibody production against SRBC, especially of IgG class, was facilitated, when cholera toxoid was given 7 days before the immunization through the footpad in DDD mice. On the other hand, antibody production was suppressed irrespective of immunizing routes and mouse strains, when cholera toxoid was given 1 day before immunization.

Animals↗
PubMed1982

Long-term evaluation of non-surgical treatment of osteoarthrosis of the temporomandibular joint.

For 25 patients with osteoarthrosis of the temporomandibular joint (TMJ), the course of the clinical symptoms consisting of limitation of mouth opening, pain, joint sound, mandibular deviation and facial deformity was studied throughout a long follow-up period. The diagnosis was based on clinical, radiographical and laboratory findings. It turned out that after a long period, only 1 patient still suffered from a disease without any improvement. Clinical signs and symptoms exhibited a tendency of gradual improvement, and the number of patients who did not attend the TMJ clinic further increased gradually after the first year. With regard to pain, only slight occasional pain was observed by 4 patients, 15 patients became free from pain, and the remaining patients did not return to the TMJ clinic after a period of 18 months. Sound produced by movements in the joint were observed in 22 patients at the first examination; at least 5 patients still had this symptom 18 months later, 10 patient only exhibited symptoms on rare occasions or were free from noises, and 7 patients no longer attended the TMJ clinic. 45.8% of the total number of patients recovered from the mandibular deviation, and 80% showed satisfactory mouth opening (more than 35 mm) at the last examination. Facial deformity was observed in at least 4 patients after a long follow-up period.

Adolescent↗
PubMed1982

Synthesis of IgM, IgG and IgA in rheumatoid arthritis.

We studied the production of immunoglobulins by lymphocytes separated from the blood of 15 rheumatoid arthritis (RA) patients, of 12 patients suffering from other connective tissue diseases (CTD), and of 18 healthy controls. The production of IgM, IgG and IgA in pokeweed-mitogen-stimulated cultures was measured by counting the number of plaque-forming cells (PFC) and by determining the concentration of secreted immunoglobulins by means of an enzyme immunoassay. Synthesis of immunoglobulins, particularly IgM and IgG, was lower than in other CTD patients or controls. The IgM response of RA patients was 20% and 29% (PFC and Ig concentrations) that of the controls. The respective figures for IgG were 33% and 53% and for IgA 61% and 72%.

Adult↗
PubMed1982

NADPH-dependence of vitamin B2-aldehyde-forming enzyme.

Vitamin B2-aldehyde-forming enzyme isolated from Schizophyllum commune with 1,400-fold purity was found to require NADPH under aerobic but not anaerobic conditions. Both NADPH- and DCIP-requiring enzyme activities which could not be separated by our enzyme purification system were found in the same single protein band on polyacrylamide disc gel electrophoresis. The cation, Cu2+, markedly stimulated the NADPH-dependent enzyme reaction under the aerobic conditions. The reagents, EDTA, pyrazole, N-ethylmaleimide, PCMB, and arsenite, inhibited the formation of vitamin B2-aldehyde to various extents, whereas azide did not.

Alcohol Oxidoreductases↗
PubMed1982

Decrease of basal plasma histamine levels by application of atropine in man.

The influence of atropine sulfate on plasma histamine levels was studied in 28 oral surgery patients with no history of allergy. 11 patients were given atropine sulfate for premedication (atropine group), and 17 patients were not (non-atropine group). The measurement of histamine in blood plasma was made using high speed liquid chromatography which was available for quantifying the trace elements. The concentration of histamine of the atropine group was 0.32 +/- 0.17 ng.ml-1 and that of the non-atropine group was 0.68 +/- 0.20 ng.ml-1, showing that atropine sulfate can suppress the release of histamine into human blood.

Adolescent↗
PubMed1981

Occurrence of a vitamin B2-aldehyde-forming enzyme in Schizophyllum commune.

Vitamin B2-aldehyde-forming enzyme from riboflavin was purified about 1,400-fold from a cell-free extract of Schizophyllum commune by ammonium sulfate saturation fractionation, ethanol fractionation, and column chromatographies on DEAE-Sephacel and Sephadex G-100. The purified enzyme was shown to be homogeneous on polyacrylamide disc gel electrophoresis, and most active at about pH 5.5. The molecular weight was determined to be approximately 60,000-62,000 by gel filtration. The enzyme was specific for riboflavin; other compounds such as alcohol, sugar, phenol or nucleoside were not oxidized by this enzyme, as far as tested. alpha-NAD+, beta-NAD+, alpha-NADP+, beta-NADP+, FMN, FAD, and cytochrome c were not active as an electron acceptor. 2,6-Dichlorophenolindophenol served as a good electron acceptor, and phenazine methosulfate and methylene blue were found to be somewhat effective. The enzyme stoichiometrically oxidized 1 mol of riboflavin with 1 mol of 2,6-dichlorophenolindophenol as electron acceptor. The enzyme reaction was completely inhibited by 10 microM Hg2+, but was not inhibited by sulfhydryl reagent, carbonyl reagent, and metal chelator. Kinetics analysis gave a Km value of 17 microM for riboflavin.

Agaricales↗