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Biomedical subjects

Y Uno

Publications and source records attributed to Y Uno.

At least 163 records · Page 9Linked to original sources
PubMed1981

The requirement for both DNA polymerase and 5' to 3' exonuclease activities of DNA polymerase I during Tn5 transposition.

By assaying transposition of Tn5 from lambda b221 cI857 rex::Tn5 (Berg 1977) in polA-proficient and deficient cells, both the polymerase activity and 5' to 3' exonuclease activity of DNA polymerase I have been shown to be required for transposition. This requirement could not be observed in three other systems in which the transposon donor replicon had existed in the PolA-proficient and deficient cells before the transposition event to be assayed occurred. By analogy to Tn3, this may indicate that the repressor encoded by Tn5 has already been expressed and hence become rate-limiting in the overall transposition process, even PolA-deficient cells still possessing a residual activity. One PolA mutant was found among more than 50 transposition deficient (tnp) mutants isolated by the use of lambda b221 cI857 rex::Tn5.

DNA Polymerase I↗
PubMed1976

Protective effect of hyperbaric oxygen for the temporary ischaemic myocardium. Macroscopic and histological data.

A protective effect of hyperbaric oxygen immediately after reopening of occluded coronary blood flow for the temporary ischaemic myocardial muscle was studied. Thirty dogs were used in this study, and 20 dogs were sacrificed after 4 h and 10 dogs were sacrificed after 5 d. Temporary occlusion of coronary artery (from 30 min to 2 h) was produced by ligation. One group were controls and the other group were a hyperbaric group in which dogs breathed 100% oxygen at an absolute pressure of 2 atmospheres before and after release of coronary ligation. The macroscopic extent of ischaemic area was studied by using nitroblue tetrazolium and microscopic and ECG findings were examined. By breathing oxygen at high pressure immediately after reopening of occluded coronary blood flow, the ischaemic area was markedly reduced. In such cases, some myocardial muscles around the arterioles and sinusoids, even when these vessels existed in the ischaemic area, were kept in a viable state. The repair of necrotic myocardial muscles was promoted histologically. Serious arrhythmia, especially ventricular fibrillation, was also well suppressed, and the stable haemodynamic conditions were obtained during operative procedures. No harmful side effects of hyperbaric oxygen were observed. One of the most effective treatments of acute myocardial infarction involves reconstruction of the occluded coronary artery as soon as possible after the onset of myocardial infarction by using these advantages of hyperbaric oxygen.

Animals↗
PubMedDate not supplied

Two-phase [11C]L-methionine PET in childhood brain tumors.

Thirteen children (1.8-15.8 years of age) with brain tumors were studied with [11C]L-methionine positron emission tomography (METPET). Patients were injected intravenously with tracer before a baseline PET scan was obtained. To assess the sensitivity of [11C]L-methionine uptake to competitive inhibition, 10 patients received oral L-phenylalanine (100 mg/kg); 1 hour later, a second METPET was obtained. Subjective assessment of [11C]L-methionine uptake closely paralleled results of quantitative examination (r = 0.81). [11C]L-methionine uptake in tumor-containing brain was increased in 11 patients (mean ratio of [11C] radioactivity in tumor to normal brain: 1.5 +/- 0.57; range: 1.13-2.98). Increased tracer uptake occurred in ependymomas (3), medulloblastoma (1), and astrocytomas (5), but was less intense in low-grade tumors. L-phenylalanine reduced L-methionine uptake (25-69%) in 70% of studies. L-methionine uptake was not sensitive to competitive inhibition in brain radiation injury. Two-phase METPET is of potential value in difficult clinical situations evident in children with brain tumors, including the differential diagnosis of tumor recurrence and cerebral radiation injury.

Adolescent↗
PubMedDate not supplied

The discrepancy of histologic diagnosis between flat early colon cancers and flat adenomas.

Although flat or depressed early colon cancer (FDEC) has increasingly been reported, its incidence is highly variable among medical institutions in Japan. We recently encountered 7 patients with a flat or depressed colonic lesion, which was completely resected by operative local excision or floatation excision biopsy (strip biopsy) including surrounding mucosa. Apparent discrepancy was noted in the histologic diagnosis between two experienced pathologists. One pathologist, associated with an institution where there has been no report of FDEC, diagnosed only one lesion as carcinoma in an adenoma with submucosal invasion and all the other lesions as flat adenomas. The other pathologist, associated with an institution where there has been a number of reports of FDEC, diagnosed 5 of 7 lesions as FDEC. These results suggest that different criteria used in each institution may be a major cause of the difference in the detection rate of FDEC.

Adenoma↗