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Biomedical subjects

T Harada

Publications and source records attributed to T Harada.

At least 1,135 records · Page 63Linked to original sources
PubMed1980

Genetic control of tyramine oxidase, which is involved in derepressed synthesis of arylsulfatase in Klebsiella aerogenes.

Mutants of Klebsiella aerogenes with three types of mutations affecting regulation of tyramine oxidase were isolated by a simple selection method. In the first type, the mutation (tynP) was closely linked to the structural gene for tyramine oxidase tynA). The order of mutation sites was atsA-tynP-tynA. In the second type, the mutation that relieves catabolite repression of the syntheses of several catabolite repression-sensitive enzymes are not linked to the tyn gene by P1 transduction. These strains contained high levels of cyclic adenosine 5'-monophosphate when grown on glucose. The third type of mutation, in which tyramine oxidase was synthesized constitutively, was shown by genetic analysis to involve mutations of tynP and tynR. The tynR gene was not linked to tynA. Results using the constitutive mutants showed that the constitutive expression of the tynA gene resulted in depression of arylsulfatase synthesis in the absence of tyramine.

Arylsulfatases↗
PubMed1980

Renin release and renal pelvic pressure in the isolated perfused dog kidney.

The perfused dog kidney was used for a study of the relationship between renin secretion and renal pelvic pressure. The kidney was completely isolated and perfused with perfluorochemical emulsion. During the elevation of renal pelvic pressure, renin secretion rate increased from 0.93 +/- 0.43 to 5.54 +/- 1.57 ng/g min, perfusion flow rate decreased temporarily and recovered within a few minutes.

Animals↗
PubMed1980

Clinical implications of alpha-fetoprotein in liver cirrhosis: five-year follow-up study.

The level of alpha-fetoprotein (AFP) was estimated by radioimmunoassay or passive hemagglutination method in a series of 159 patients with liver cirrhosis, and the incidence of serum hepatitis B antigen, histopathologic features of the liver, incidence of development of hepatocellular carcinoma (HCC) and mortality in AFP-positive cases were studied. Approximately 40 per cent of the patients had an AFP level higher than 20 ng/per ml, and all the elevations of AFP over 100 ng per ml were transient. In contrast, patients who developed HCC during the course of the disease always exhibited an increasing value of AFP. The seropositivity for AFP was significantly related to the presence of serum hepatitis B surface antigen and also to liver cell dysplasia as well as to thickening of the liver cell plates. As compared with a group of AFP-negative cases, the AFP-positive group showed a higher incidence of development of HCC and poorer prognosis over a five-year follow-up period. The data obtained suggested that increased AFP-production in patients with liver cirrhosis might reflect, largely an abnormal or altered liver cell regeneration, probably associated with hepatitis B virus, and that patients with transiently elevated AFP values might be at greater risk for the development of HCC.

Carcinoma, Hepatocellular↗
PubMed1980

[The association of cerebral aneurysm with malignant brain tumor--report of a case (author's transl)].

A rare case was reported in which a brain tumor was associated with a cerebral aneurysm. A 59-year-old woman was admitted with right spastic hemiparesis and motor aphasia. She was in somnolence and complained of headache. She had two attacks of loss of consciousness about 12 years previously. Since then she had right spastic hemiparesis and motor aphasia as sequelae. Preoperative CT scan and carotid angiograms showed a malignant brain tumor in the left temporal region and an anterior communicating artery aneurysm. Operation was performed in one stage. At first the neck of the aneurysm was clipped by right sphenoidal approach and the tumor was partialy removed by left temporal approach. The histological diagnosis was glioblastoma multiforme. The cerebral aneurysm associated with brain tumor should be treated as soon as possible. The operative result in our case was good.

Brain Neoplasms↗
PubMed1980

Studies of alpha-napthylisothiocyanate-induced hepatic disturbance.

In order to clarify the mechanism of alpha-naphthylisothiocyanate (ANIT) induced cholestasis in rats, a few hepatic changes seen after administration of ANIT 80 mg/kg body weight were examined in relation to time. To clarify changes in the bile production system and bile flow, the concentrations of bile acid and bicarbonate, as well as of sodium in the bile, were measured after infusion of secretin and taurocholic acid. The canalicular bile flow was estimated by measuring the biliary clearance of erythritol-C14. To assess hepatocellular injury, the levels of cytochrome P-450 in the microsome of hepatocytes and protein synthesis in the liver were estimated. It seems that ANIT is activated in the drug metabolising system through cytochrome P-450 in the liver, and significant changes are produced in both the bile acid metabolism and its transport system. Bile acid-independent bile flow in the canaliculus was inhibited, too. Hence, both the bile ductules and the bile ducts are functionally and histologically disturbed.

1-Naphthylisothiocyanate↗
PubMed1979

Cyclophosphamide eliminates suppressor T cells in age-associated central regulation of delayed hypersensitivity in mice.

Effect of treatment of mice with cyclophosphamide (CY) on the delayed hypersensitivity (DH) response was investigated in C57BL/6 mice. DH to methylated human serum albumin (MHSA) could be enhanced with CY in young mice but not in aged ones. DH enhancement with CY appeared to be due to elimination of suppressor T cells involved in DH. Effector T cells were also sensitive to CY, the damaging effect of CY on these latter cells was, however, transient suggesting the rapid recovery of effector T cells. The overshooting recovery of the effector T cells required the presence of the thymus. It is more probably that there are at least two distinct subpopulations of T cells in DH, effector T cells, and suppressor T cells. The distinction is already apparent in the thymus stage. The suppressor T cells, categorized as a central regulator, seem to be antigen nonspecific and regulate the more effectively the DH in young mice, thus physiological role of these cells in age-associated immune alterations is implicated.

Aging↗
PubMed1979

Immunohistochemical study of the medullary thyroid carcinoma with reference to C-thyroglobulin reaction of tumor cells.

Twelve cases of medullary thyroid carcinoma were investigated ty the immunoperoxidase method using anti-calcitonin, anti-C-thyroglobulin (C-Tg, C cell-immunoreactive thyroglobulin) and anti-19S thyroglobulin antisera. Tumor cells as well as normal C cells revealed distinct immunoreaction for C-Tg besides for calcitonin. In contrast to normal C cells, the tumor cells were stained more intensely by anti-Ctg antiserum than by anti-calcitonin antiserum. Furthermore, there occurred several tumors or some areas of tumors which showed strong response to anti-C-Tg antiserum but weak or no response to anti-calcitonin antiserum. Thus, medullary carcinoma cells synthesized far greater amounts of C-Tg than calcitonin. The small follicles were occasionally observed mingled in typical cell solid masses. They stored colloid-like materials which were intensely immunoreactive to C-Tg but nonreactive to calcitonin. The specific immunoreaction patterns to anti-C-Tg and anti-calcitonin antisera were also obtained on the ground materials of the amyloid. On the histogenesis of amyloids of medullary carcinoma, the C-Tg could be the presursor of the fibrillar protein of amyloids and the component of the fibrillar protein also closely related to calcitonin.

Amyloid↗
PubMed1979

A case report of leiomyosarcoma originating in the ligamentum teres of the liver.

A case of leiomyosarcoma that appeared to have originated in the ligamentum teres hepatis of a 66-year-old female has been presented. The case was suspected of leiomyosarcoma originating in the ligamentum teres of the liver from the findings by preoperative examinations, and definitely diagnosed as such in a laparotomy and by histological examination of the resected tissue specimen.

Female↗