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Biomedical subjects

M Okabe

Publications and source records attributed to M Okabe.

At least 433 records · Page 24Linked to original sources
PubMed1983

Molecular features and immunological properties of lactate dehydrogenase C4 isozymes from mouse and rat testes.

With the use of a computer graphics system, spacefilling models of mouse and rat testis lactate dehydrogenase C4 (LDH-C4) isozymes were constructed from amino acid sequence and published x-ray diffraction data. Thirty-two residues that differ between the mouse and rat LDH-C4 sequences are also displayed on the monomeric and tetrameric lactate dehydrogenase molecules. Immunological properties of mouse and rat LDH-C4 isozymes are compared and related to these 32 differences. Possible relationships between the structure, especially the amino acid sequence, and the unique enzymatic properties of LDH-C4 isozymes are also discussed.

Amino Acid Sequence↗
PubMed1983

Amino acid sequence studies on lactate dehydrogenase C4 isozymes from mouse and rat testes.

Carboxymethylated sperm-specific lactate dehydrogenase isozyme C4 (LDH-C4) proteins from mouse and rat testes were cleaved with cyanogen bromide and trypsin. Proteins were also citraconylated and digested with trypsin. In the case of mouse LDH-C4 isozyme, all 7 CNBr and 11 limited tryptic (arginine) peptides were isolated and sequenced. Some of the CNBr peptides were further fragmented with trypsin and chymotrypsin and their compositions and/or sequences characterized. Also, 34 of the 36 expected tryptic peptides were purified, and their compositions and sequences determined. Amino acid sequences of these peptides purified from mouse LDH-C4 were overlapped into a complete covalent structure of the 330 residues. For rat LDH-C4, 5 of 6 expected CNBr peptides, 5 of 8 expected arginine peptides, and 28 of the 34 expected tryptic peptides were isolated, and their compositions and sequences were determined. Some of the CNBr and arginine peptides were further fragmented with chymotrypsin, thermolysin, or V8 protease, and their compositions and/or sequences characterized. The amino acid sequence of 85% of the 330 residues from rat LDH-C subunit has been unambiguously determined, and the sequences of the remaining regions were tentatively aligned on the basis of peptide compositions and sequence homologies with the other known lactate dehydrogenase sequences, including mouse LDH-C. A comparison of the proposed rat LDH-C sequence with the complete covalent structure of mouse LDH-C indicates that 27 differences are located in the established rat LDH-C sequence of 280 residues and that 5 additional differences are in the tentative sequence of the remaining 50 amino acids.

Amino Acid Sequence↗
PubMed1983

Effect of intrasplenic injection of allogeneic bone marrow cells on the survival of lethally X-irradiated mice.

Radiation chimeras in mice were induced by intrasplenic injection of allogeneic bone marrow cells instead of intravenous injection. Interestingly, the survival time in X-irradiated BALB/c mice inoculated intrasplenically (i.s.) with bone marrow cells from C3H/He mice was markedly prolonged as compared with that in X-irradiated BALB/c mice inoculated i.v. with bone marrow cells from C3H/He mice. However, when C57BL/6 mice were used as donors, a significant difference between i.s. injection and i.v. injection has not been found in survival time at 60 days after X irradiation. On the contrary, when bone marrow cells from BALB/c or C57BL/6 mice were injected into X-irradiated C3H/He mice, i.s. injection gave longer survival days to recipients than did i.v. injection. Based on testing their chimerism, it was suggested that lymphoid cells of donor origin were predominantly identified in almost all BALB/c or C3H/He recipients which were inoculated i.s. with bone marrow cells from C57BL/6 mice. However, somewhat incomplete chimerism was observed when the C3H/He to BALB/c donor-recipient combination was used and vice versa.

Animals↗
PubMed1983

Longitudinal studies of cytomegalovirus-specific cell-mediated immunity in congenitally infected infants.

Characteristics of specific cell-mediated immunity in infants with congenital cytomegalovirus (CMV) infection were studied by in vitro lymphocyte transformation test, using the whole blood culture technique. Subjects were 6 symptomatic congenitally infected infants, 11 asymptomatic congenitally infected infants, 3 postnatally infected infants, and 5 CMV-free infants. Among them, three symptomatics and seven asymptomatics were studied temporally, together with three postnatally infected infants and five controls. In the congenitally infected group, 18 of 47 (38%) specimens proved to be negative in terms of stimulation index values. Studies of temporal changes in CMV lymphocyte transformation tests revealed that in the postnatally infected group, the response turned positive in accordance with the appearance of CMV viruria and remained positive afterwards. In the congenitally infected group, the delay in development of positive reaction followed initial negativity, a phenomenon conspicuously observed in the symptomatic subjects. No significant difference was seen in phytohemagglutinin-induced lymphocyte transformation tests among congenital, postnatal, and control groups.

Antigens, Viral↗
PubMed1983

Cold pressor test and variant angina.

A transient complete coronary occlusion due to spasm was induced by the cold pressor test in a 51-year-old man with variant angina. Arteriography before the test revealed a normal left coronary artery and only minor irregularities of the mid-portion of the right coronary artery. Three minutes after cold stimulation, angina pectoris accompanied by ST-segment elevation was observed in lead II ECG. Simultaneous coronary arteriography during the attack showed a complete occlusion of the proximal right coronary artery due to spasm. The anginal attack together with spastic occlusion disappeared after administration of 0.8 mg of nitroglycerin. Thus, the cold pressor test can trigger coronary artery spasm and may even lead to a total occlusion in patients with variant angina. Individuals with variant angina may be subjected to additional risk when exposed to cold temperatures.

Angina Pectoris, Variant↗
PubMed1983

[Case of simultaneous multiple primary lung cancer].

The incidence of multiple primary bronchogenic carcinomas has increased in Japan as the incidence of bronchogenic malignancy has increased. The patient was a 71-year-old man with simultaneous multiple bronchogenic carcinomas. He had large cell carcinoma in the left upper lobe and adenocarcinoma in the left lower lobe. We reviewed 66 reported Japanese cases with multiple lung cancers with special reference to sex distribution, age, simultaneous or metachronous, location, histological types, treatment and prognosis.

Adenocarcinoma↗
PubMed1983

Immune-enhancing effect of recombinant human interferon-beta produced in Escherichia coli on human peripheral blood mononuclear cells in vitro.

Highly purified recombinant fibroblast interferon produced by Escherichia coli (ReIFN-beta) was tested for its ability to stimulate natural killer (NK) cell activity, antibody-dependent cell-mediated cytotoxicity (ADCC) and monocyte-macrophage phagocytic activity in human peripheral blood mononuclear cells (PBM) in comparison with natural human fibroblast interferon (IFN-beta). The NK cell activity against target cells (K-562, Molt-3, CCRF-HSB-2, CCRF-CEM, Daudi, and HeLa S3) was enhanced by ReIFN-beta and IFN-beta. Augmentation of cytotoxicity of NK cells was observed at a concentration of ReIFN-beta as low as 1 U/ml and increased in a dose-dependent manner. The enhancing effect of ReIFN-beta was expressed sufficiently during a 1-hr incubation with effector cells, and IFN-beta showed kinetics and potency similar to those of ReIFN-beta. ADCC was measured with chicken red blood cells (CRBC) or CCRF-CEM coated with each antibody, as target cells. Pretreatment of PBM with ReIFN-beta caused a significant increase in ADCC activity against both targets, and the enhancing activity of ReIFN-beta was similar to that of IFN-beta. Phagocytic activity of adherent cells in PBM against CRBC was enhanced by ReIFN-beta and IFN-beta as determined by microscopical cytologic examination and by the 51Cr-labeled CRBC-uptake method. From these results, it can be concluded that recombinant human IFN-beta modulates NK cell activity, ADCC and phagocytic activity of human PBM as effectively as natural human IFN-beta.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1983

Tumor dependency of concanavalin A-induced potentiation of tumor cell immunogenicity.

The immunogenicity of concanavalin A (Con A)-treated tumor cells was examined in 4 histologically distinct tumors originated from 3 different strains of mice. In all of these tumors, Con A-treated tumor cells induced stronger tumor-specific immunity than Con A-free tumor cells as determined from the survival of sensitized mice after live tumor cell inoculation. However, Con A-induced potentiation of tumor cell immunogenicity was dependent on 2 experimental factors associated with the tumor cell vaccine preparation. One was the agent used for inhibiting in vivo transplantability of tumor cells and the other was the dose of tumor cell vaccine. In Meth A, Meth 1, and Lewis lung tumors, glutaraldehyde and Con A-treated cells, but not mitomycin C and Con A-treated cells, induced an enhanced immune resistance, whereas in L1210 leukemia, mitomycin C was more beneficial than glutaraldehyde. Higher doses of Con A-treated tumor cells (up to 10(7)) induced stronger immune resistance in Meth A and Meth 1 tumors, as was the case with L1210 tumor, whereas in Lewis lung tumor there existed an optimal vaccine dose. These results indicate a tumor species dependence of pretreatment agents and cell vaccine doses in inducing immune resistance, although Con A potentiated the immunogenicity of all the tumors tested.

Animals↗
PubMed1983

[Clinical application of a new right subcostal approach in the evaluation of interatrial septal motion].

We developed a new echocardiographic approach to detect the interatrial septum (IAS) by tilting a transducer leftward, cephalad and backward from the right subcostal area. This technique could allow us to visualize the IAS moving perpendicularly to the ultrasonic beam. In normal subjects the IAS showed a small posterior deflection moving toward the left atrium due to atrial contraction following the P wave of the electrocardiogram. Following the onset of ventricular ejection the IAS rapidly moved anteriorly. During diastole the IAS showed an initial rapid posterior displacement and then a more gradual slope, reflecting rapid and slow filling phases, respectively. The magnitude and configuration of IAS motion showed variations dependent on atrial conditions of cardiac diseases. In atrial fibrillation there were f waves on the IAS echogram and in mitral stenosis a septal notch was recorded at the timing of a mitral opening snap. In mitral valve prolapse there was also a midsystolic notch of the IAS echogram almost coincident in time with the onset of a late systolic murmur. On the other hand, the IAS revealed a systolic increased excursion or paradoxical motion in mitral or tricuspid regurgitation, respectively. In hypertension and myocardial infarction the atrial kick of the IAS echogram showed an exaggerated excursion. In 125 out of the consecutive 150 cases (83.3%) we could record satisfactory IAS echograms by this new approach.

Adolescent↗