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Biomedical subjects

T Ohta

Publications and source records attributed to T Ohta.

At least 1,297 records · Page 72Linked to original sources

Structural studies of a human gamma 3 myeloma protein (Jir) bearing the allotypic marker Gm(st).

The authors established the amino acid substitutions determining G3m(s) and G3m(t) specificities, which characterize Mongoloid populations, by sequence analysis of the Fc region of a myeloma protein (Jir). By comparing the amino acid sequences of the IgG3 (Jir) and the other IgG subclasses analyzed to date, it was found that G3m(s) was an isoallotype specified by an amino acid substitution at position 435; i.e., whereas the subclasses IgG1, IgG2, and IgG4 had histidine in common, G3m(s-) had arginine in this position. This was also confirmed by the observation that the Fc fragment in question bound to protein A. It was also established that the amino acid at position 379 of G3m(t-) IgG3 and the other subclasses was valine, whereas methionine in this position was specific for G3m(t+). In addition, the amino acids at position 339 of G3m(u-) IgG3 Jir was threonine, and at position 296 of G3m(g-) IgG3 Jir was tyrosine. These findings are not in accord with the hitherto postulated relations of alanine and phenylalanine to G3m(u-) and G3m(g-), respectively. Finally, this study showed that a large number of substitutions occurred at positions 384 through 389, which suggests that many specificities of the G3m(b) group occur on IgG3 proteins.

Amino Acid Sequence↗

Structural analysis of bovine mitochondrial tRNASer (AGY).

Mitochondrial serine tRNA lacking D stem (anticodon AGY) was purified from bovine cardiac muscle in the mg order. The nucleotide sequence was identical to that reported previously, with t6A adjacent to the 3' end of anticodon (Arcari, P. and Brownlee, G.G. (1980) Nucleic Acids Res. 8 5207-5212). The procedures for large scale preparation and some properties of this tRNASer are reported.

Animals↗

Congenital absence of the right pulmonary artery--a case report and review.

Congenital absence of one of the pulmonary arteries not accompanied by other congenital heart disease is rare. Less than 90 cases have been reported since Fräntzel noted the first case in 1868 (5). In Japan, Osano first reported a case of an 11-year old boy with unilateral absence of the right pulmonary artery (8). This is a report of a case of an 8-month-old girl in whom initial diagnosis of absence of the right pulmonary artery was made by investigation of plain chest X-ray film, and the final diagnosis was made by cardiac catheterization. The problems of etiology, diagnosis, and treatment of absence of a pulmonary artery are reviewed.

Female↗

[Pathogenesis and prevention of the revascularization syndrome].

Revascularization syndrome is one of the dangerous postoperative complications which results sometimes in loss of a limb, renal shutdown and death due to myoglobin-nephrosis and hyperkalemia. During the past 3 years, 2 cases of revascularization syndrome were experienced in 16 cases of thrombo-embolectomies for acute peripheral arterial occlusion. One patient died from hyperkalemia 100 minutes after revascularization. Another patient suffered from a renal shutdown, and was treated with hemodialysis and thigh amputation. It is sometimes very difficult to predict whether the revascularization syndrome will occur or not. When revascularization is performed within 12 hours after an onset of acute occlusion and when the amount of ischemic muscle is not large, the syndrome may not occur. When the time-interval between the onset of ischemia and revascularization is longer than 24 hours and when the mass of ischemic muscle is large, the syndrome will occur. Preoperative serum creatinine and urea nitrogen level are important parameters predicting the prognosis.

Acute Disease↗

Purification, characterization and development of radioimmunoassay of human liver ribonuclease.

Human liver ribonuclease (RNase) was purified 36000-fold into an electrophoretically homogeneous state by column chromatography on phosphocellulose, gel filtration, poly(G) affinity chromatography, and heparin affinity chromatography. The molecular weight of the RNase estimated by SDS disc electrophoresis was 19,500. RNase was a heat- and pH-stable protein, and optimum activity was obtained at pH 7.0. The radioimmunoassay (RIA) for human liver RNase has been developed and the assay was shown to be sensitive (20 ng/ml), reproducible and specific. A good parallel relationship was observed between the standard curve and the dilution curves for serum and urine. No cross-activity was demonstrated between human liver and pancreatic RNase (less than 1%). In 44 normal subjects, the mean serum concentration of liver RNase determined by the RIA was found to be 99.4 ng/ml (SD +/- 66.3).

Adult↗

Conservative treatment of inoperable arterial occlusions of the lower extremities with intra-arterial prostaglandin E1.

Prostaglandin E1 has a strong vasodilator effect, it inhibits the aggregation of platelets and improves the microcirculation. The hormone is synthesized from arachidonic acid and 80-90 per cent is eliminated in the first transit of the pulmonary circulation. From 1 January 1978 to 30 June 1981 100 patients suffering from inoperable occlusion of the arteries of the lower limbs and facing amputation were treated with intra-arterial PGE1 by prolonged perfusion over an average period of 34 days. PGE1 0.1-0.2 ng kg-1 body weight min-1 was administered. Forty-seven of 100 legs were saved; 22 of 29 patients suffering from diabetes requiring insulin had to undergo amputation, but only 1 of 18 patients suffering from thromboangiitis obliterans had to have an amputation. The results of treatment in the 52 cases of uncomplicated arteriosclerosis lie in between, with 18 amputations. The complications that followed treatment were haemorrhage, arterial thrombosis, infection and mycotic aneurysms.

Adult↗

Correlation between body surface isopotential maps and left ventriculograms in patients with old inferoposterior myocardial infarction.

In 24 patients with old inferoposterior myocardial infarction, body surface isopotential maps were compared with left ventriculographic findings. In 16 patients with asynergy restricted to the inferior and/or posterolateral segment, surface potential abnormalities due to infarction were observed during specific phases of QRS and in specific portions on the chest surface depending on the location and extent of ventricular severe asynergy (akinesis and dyskinesis). However, the remaining eight patients with coexisting severe asynergy in the anterior, apical, or septal segment showed surface potential maps quite different from those of the former patients. It is suggested that body surface isopotential maps are a useful clinical tool for detecting the location and extent of ventricular severe asynergy in patients with old inferoposterior myocardial infarction.

Aged↗

Thiobarbituric acid reactive substances and vitamin E in serum and cerebrospinal fluid from patients with cerebral apoplexy.

Thiobarbituric acid (TBA) reactive substances in serum and cerebrospinal fluid from patients with cerebral apoplexy were determined and their relationship to this disease was studied. TBA reactants in serum were elevated in patients with cerebral apoplexy, but there was no difference between patients with brain tumor or other neurological disease and healthy persons. TBA reactants in cerebrospinal fluid in patients with cerebral aneurysm, cerebral arterial and venous anomalies or intracerebral hematoma, and its levels in patients with cerebral infarction or brain tumor were also higher than in healthy persons. Serum alpha-tocopherol levels were elevated in patients with cerebral infarction, but were relatively low in patients with cerebral aneurysm, cerebral arterial and venous anomalies or intracerebral hematoma. The reverse was the case with cerebrospinal fluid levels of alpha-tocopherol. That is, the sequence of decreasing level of alpha-tocopherol in cerebrospinal fluid was intracerebral hematoma, cerebral aneurysm, cerebral arterial and venous anomalies, and cerebral infarction. The levels of TBA reactive substances in patients with cerebral apoplexy showed a positive correlation between serum and cerebrospinal fluid, and the levels of alpha-tocopherol showed a similar correlation.

Aged↗