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Biomedical subjects

K Sakaguchi

Publications and source records attributed to K Sakaguchi.

At least 433 records · Page 24Linked to original sources
PubMed1982

Protein contents and binding modes of immunoglobulin-amylase complexes.

The protein contents and binding modes of immunoglobulin-amylase complexes were investigated. Amylase staining after immunoelectrophoresis permitted identification of IgA-lambda type in three cases, IgA-kappa type in two cases and IgG-kappa type in one case. The precipitin line of Fab fragment of IgA in four patient's sera after papain digestion was found to have amylase activity. Sucrose density gradient ultracentrifugation studies showed that these complexes were divided into three groups: Group I complexes were dissociated in acid pH, and at pH 7.0 the immunoglobulins, which were isolated at the acid pH, became rebound to serum amylase; Group II complexes were dissociated by acidification, but did not reform at pH 7.0; Group III complexes were unaffected by acidification. We suggest that the immunoglobulin-amylase complexes belonging to groups I and II result from an antigen-antibody reaction. Precipitin curves resulting from the addition of increasing quantities of the patient's serum containing 9 S or 11 S immunoglobulin-amylase complexes to specific antisera revealed that these complexes contained not only monoclonal IgA, but also alpha-1-antitrypsin (alpha 1 AT) and albumin. These IgA complexes could have bound non-specifically to alpha 1 AT and albumin, forming the larger macroamylase complexes.

Aged↗
PubMed1982

A case of multiple endocrine neoplasia type II b: endocrinological evaluation and family screening.

The case of a 27 year-old woman with typical manifestations of multiple endocrine neoplasia type II b is reported. Medullary carcinoma of the thyroid was detected on the occasion of an operation for goiter when she was 22 years of age. Constipation due to megacolon caused by intestinal neuroma had persisted since childhood. Neuroma of the tongue and lips, hypertrophic corneal nerve and Marfanoid habitus were also found. The presence of pheochromocytoma was suggested in view of the positive cold pressor and results of glucagon loading tests, but this remains inconclusive. There was prolonged and exaggerated response of growth hormone and luteinizing hormone after provocative tests for anterior pituitary gland, in spite of normal basal levels. Screening of her family members for medullary carcinoma of the thyroid was carried out by measurement of immunoreactive calcitonin. Two siblings were shown to be hypercalcitoninemic, presumably due to occult medullary carcinoma of the thyroid. This case appeared to be the first in Japan showing multiple endocrine neoplasia type II b accompanied by familial hypercalcitoninemia.

Adrenal Gland Neoplasms↗
PubMed1982

[Moderate dose methotrexate with citrovorum factor rescue therapy in the treatment of head and neck cancer].

A clinical trial of moderate dose methotrexate (MTX)-CF rescue was conducted in 12 institutions. Thirty-seven patients with head and neck carcinoma entered this trial, of which 32 were evaluable. MTX was administered 350 mg/m2 (500 mg/body) by i.v. drip over 6 hours. Three hours after completion of MTX infusion, CF rescue was started. There was no complete response in 32 patients. Nine patients showed partial response with the response rate of 28%. The response rates were 21% for the group of patients treated previously, and 75% for the group untreated previously. MTX concentration in plasma was determined at 6, 24, 48 and 72 hours after the initiation of MTX infusion, and the assay results revealed a safe range. GI disturbances were seen at the rates of 11 to 38%. Bone marrow suppression was mild and no renal toxicity was observed. We concluded that the moderate dose MTX-CF rescue therapy was useful for head and neck carcinoma. As a next step, we are planning to conduct a clinical trial of high-dose MTX.

Adult↗
PubMed1982

Diagnostic standards for occupational nasal allergy.

Based on studies of 70 outpatients having occupational nasal allergy as well as mass examinations of workers in two industries, diagnostic standards for this condition were evaluated. In practice, interviews concerning the causal relation, frequency, latent period and atopic disposition often provide suggestions, but sometimes give unreliable evidence for the basis by which to diagnose occupational nasal allergy. Both rhinoscopy and nasal smear test for eosinophilia are available, but these only distinguish allergy from non-allergy. Therefore, examinations, such as skin tests, nasal tests and determination of the IgE antibody level, using allergen extract of good quality, are necessary for a final diagnosis.

Air Pollutants, Occupational↗
PubMed1982

Effects of colchicine, Colcemid and vincristine on ethyl methanesulfonate-induced sister chromatid exchanges and chromosomal aberrations in Chinese hamster cells.

The effect of colchicine, Colcemid and vincristine on ethyl methanesulfonate-induced sister chromatid exchanges and chromosomal aberrations was studied in Chinese hamster cells. The number of ethyl methanesulfonate-induced sister chromatid exchanges was markedly decreased with increasing doses of colchicine and vincristine. In the presence of colchicine, ethyl methanesulfonate-induced chromosomal aberrations increased; these were mainly breaks and fragmentations. The effects were most prominent at the earlier stage of the cell cycle. Colchicine, Colcemid and vincristine had no effect on spontaneous sister chromatid exchanges or chromosomal aberrations.

Animals↗
PubMed1981

Inhibition of protein synthesis antagonizes induction of sister-chromatid exchanges by exogenous agents.

Cycloheximide (CH) and puromycin (PM)strongly antagonize induction of sister-chromatid exchanges (SCEs) by exogenous agents regardless of the mechanism for initiating damage. 5-Bromodeoxyuridine (BUdR) substitution was used to monitor SCEs, but the background level of BUdR-induced SCEs was unaffected by the presence of protein inhibitors. Antagonism between DNA-damaging agents and protein inhibitors was strongest in euchromatic regions. Possible relationships between SCE formation and the mechanism of antagonism by protein inhibitors are discussed.

Animals↗
PubMed1981

Inhibition of platelet aggregation by 1-alkylimidazole derivatives, thromboxane A synthetase inhibitors.

1-Alkylimidazole derivatives of various sidechain lengths with various functional groups at the terminal end of the alkylchain inhibited the synthesis of thromboxane A2 from arachidonic acid by rabbit platelets and the conversion of prostaglandin H2 to thromboxane A2 by the microsomes of rabbit platelets. These enzyme inhibitors were anti-aggregatory as examined with rabbit and human platelet-rich plasma under various experimental conditions.

Animals↗
PubMed1981

Isolation and characterization of linear deoxyribonucleic acid plasmids from Kluyveromyces lactis and the plasmid-associated killer character.

Two linear deoxyribonucleic acid plasmids, designated pGK11 and pGK12, were isolated from the yeast Kluyveromyces lactis IFO 1267. pGK11 and pGK12 had molecular weights of 5.4 X 10(6) and 8.4 X 10(6), respectively. Both plasmids possessed the same density of 1.687 g/cm3, lighter than the densities of mitochondrial (1.692 g/cm3) and nuclear (1.699 g/cm3) deoxyribonucleic acids. A restriction map of pGK11 was constructed from digestions by EcoRI, HindIII, PstI, and BamHI. pGK12 was cleaved by EcoRI into seven fragments and by BamHI into two fragments K. lactis IFO 1267 killed Saccharomyces cerevisiae sensitive and killer strains and certain strains of Saccharomyces italicus, K. lactis, Kluyveromyces thermotolerans, and K. vanudenii. All K. lactis strains lacking the pGK1 plasmids were nonkillers. A hybrid was constructed between K. lactis IFO 1267 and a nonkiller K. lactis strain lacking the plasmids and subjected to tetrad analysis after sporulation. The killer character was extrachromosomally transmitted in all tetrads in association with the pGK1 plasmids. The double-stranded ribonucleic acid killer plasmid could not be detected in any K. lactis killer strains. It is thus highly probable that the killer character is mediated by the linear deoxyribonucleic acid plasmids. A single chromosomal gene was found which was responsible for the resistance to the K. lactis killer.

Ascomycota↗
PubMed1981

Intergeneric transfer of deoxyribonucleic acid killer plasmids, pGKl1 and pGKl2, from Kluyveromyces lactis into Saccharomyces cerevisiae by cell fusion.

Two novel linear deoxyribonucleic acid plasmids, pGKl1 and pGKl2, were isolated from the yeast Kluyveromyces lactis. K. lactis strains harboring the pGK1 plasmids killed a certain group of yeasts, including Saccharomyces cerevisiae, Saccharomyces italicus, Saccharomyces rouxii, K. lactis, Kluyveromyces thermotolerans, Kluyvermyces vanudenii, Torulopsis glabrata, Candida utilis, and Candida intermedia. In this experiment, the pGKl1 and pGKl2 plasmids were intergenerically transferred from a K. lactis killer strain into a non-killer (killer-sensitive) strain of S. cerevisiae by the use of a protoplast fusion technique. Both of the pGKl plasmids replicated autonomously and stably in the new host cells of S. cerevisiae and could coexist with the resident 2-micrometers deoxyribonucleic acid plasmid. The S. cerevisiae cells which accepted the pGKl plasmids expressed the same killer phenotype as that of the donor K. lactis killer and became resistant to the K. lactis killer. The pGKl plasmids existing in the S. cerevisiae cells were cured by treatment with ethidium bromide, and the killer and resistance characters were simultaneously lost. From there results, it was concluded that both the killer and the resistance genes are located on the pGKl plasmids.

Ascomycota↗
PubMed1981

Curing of the killer deoxyribonucleic acid plasmids of Kluyveromyces lactis.

Ultraviolet irradiation gave rise to frequent curing of killer plasmids pGKl1 and pGK12 of Kluyveromyces lactis. Almost all of the nonkillers obtained lost both plasmids, but one of them lost only pGKl1. The disappearance of pGKl1 was accompanied by the simultaneous loss of the killer activity and of the resistance to the killer factor. A new plasmid, pGKl1S, was obtained, which arose from a deletion in the central region of pGKl1. Genetic analysis suggested that pGKl1S has the killer gene lost by the deletion and the resistance gene intact and that pGKl1S shares the same replication control with pGKl1.

Ascomycota↗
PubMed1981

The usefulness of thallium-201 myocardial perfusion scintigraphy in the diagnosis of chronic cor pulmonale.

To open up the possibility of exact clinical diagnoses of chronic cor pulmonale, we performed thallium-201 myocardial perfusion scintigraphy on patients with chronic pulmonary disease. From the thallium activity in the left ventricle (plus ventricular septum) and right ventricle counted scintigraphically, we determined the thallium activity ratio of left to right ventricle (TAR). The intra- and inter-observer variations of this ratio were negligible. We compared TAR with pulmonary hemodynamic findings and with left to right ventricular mass ratio measured at autopsy, and obtained the following results. 1) Left to right ventricular mass ratio determined in 11 autopsied patients by the method of Fulton et al. was closely correlated with TAR values (r = 0.90, p less than 0.001). 2) In patients with chronic pulmonary disease, there were highly significant exponential inverse correlations between TAR and pulmonary arterial mean pressure, total pulmonary vascular resistance and right ventricular systolic pressure the the coefficients of -0.75, 0.72 or -0.77, respectively (p less than 0.001). These results suggested the possibility that the severity of pulmonary circulatory disturbance may be ascertained non-invasively by TAR measurement. Thus, thallium-201 myocardial perfusion scintigraphy is able to reveal non-invasively right ventricular hypertrophy in patients with chronic pulmonary disease, and it might be a useful means of clinically diagnosing chronic cor pulmonale. If TAR obtained from scintigrams is smaller than 2, the patient concerned may possibly have right ventricular hypertrophy and he or she may be diagnosed as having chronic cor pulmonale.

Adult↗
PubMed1981

Immunochemical studies on heterogeneity of IgD myeloma proteins.

An antigenic heterogeneity among IgD myeloma proteins was tested by immunoelectrophoresis and double immunodiffusion in agar with four kinds of anti-delta(Fc) antisera produced by immunization with isolated Fc fragments of IgD myeloma proteins. According to antigenicity of the Fc fragment, IgD myeloma proteins were divided into two different groups. Anti-delta(Fc)-T1 (S.T.) antiserum, absorbed with te Y.S. myeloma protein or serum, either gave a faint precipitin line or failed to react against the isolated IgD myeloma proteins or sera. With the papain-digested IgD myeloma proteins and sera, anti-delta(Fc)-T1 antiserum either gave heavy precipitin lines or failed to react. Of twelve papain-digested sera containing IgD myeloma proteins tested, nine (75%) showed positive precipitin lines using anti-delta(Fc)-T1 antiserum. No relationship was found between the two groups of myeloma proteins with respect to IgD levels. SDS polyacrylamide gel electrophoresis of the IgD myeloma proteins (S.T. and Y.S.) showed no difference in the molecular weights of the whole myeloma proteins, and their light and heavy chains. Polyacrylamide gel electrophoresis of the IgD myeloma proteins (S.T. and Y.S.), after treatment with papain, revealed almost the same patterns.

Chromatography, Gel↗
PubMed1981

[Assessment of hypertrophic cardiomyopathy by ECG gated cardiac computed tomography (author's transl)].

The applicability of ECG gated cardiac computed tomography (CT) in 12 patients with hypertrophic cardiomyopathy was examined. Six of the 12 patients had hypertrophic obstructive cardiomyopathy, including one patient with mid-ventricular obstruction. Three of the 12 patients had hypertrophic non-obstructive cardiomyopathy, and three had apical hypertrophic cardiomyopathy. The diagnosis of hypertrophic cardiomyopathy was confirmed by the angiocardiogram in all patients. Cardiac CT was performed after intravenous administration of contrast media usually given as a bolus injection. The gantry was set with positive 20 degree tilt angle. In all patients with hypertrophic obstructive cardiomyopathy except for mid-ventricular obstruction, the hypertrophied interventricular septum in the basal and mid portions was observed, and the left ventricular cavity was narrowed in systole. In a patient with mid-ventricular obstruction, the marked hypertrophied interventricular septum and antero-lateral papillary muscle were observed. In diastole, the left ventricular cavity was narrow and divided into two parts. The apical cavity was completely disappeared in systole. In all patients with hypertrophic non-obstructive cardiomyopathy, the diffuse hypertrophied interventricular septum was observed in diastole. In systole, the apical portion of the left ventricular cavity was markedly narrow and anterio-lateral papillary muscle was hypertrophic. In all patients with apical hypertrophic cardiomyopathy, the marked apical hypertrophy of the left ventricular wall was observed in diastole. It is concluded that ECG gated cardiac CT could estimate myocardial wall motion and thickness and differentiate the types of hypertrophic cardiomyopathy each other.

Adult↗