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Biomedical subjects

T Noda

Publications and source records attributed to T Noda.

At least 379 records · Page 21Linked to original sources

Identification of two distinct elements in the long terminal repeat of HTLV-I responsible for maximum gene expression.

Human T-cell leukemia virus type I has a unique sequence, pX, between env and the 3' long terminal repeat (LTR). One of its products, p40, activates gene expression directed by the LTR in a trans-acting manner. We have analysed the mechanism of this trans-activation mediated by p40 in human T cells co-transfected with a plasmid expressing p40 using the transient CAT gene expression. We identified two distinct elements in the LTR which are involved in maximum gene expression. The first was present in a 230-bp fragment upstream from TATA box in the U3 region and behaved as a classical enhancer. This region was also shown to be responsible for trans-activation by p40. This element alone together with functional p40 could direct the gene expression at only approximately 10% of the level achieved by the complete LTR and p40. The second element was present within a 300-bp fragment downstream from the RNA start site and profoundly enhanced the gene expression in a way independent from trans-activation mechanism. This enhancement was observed only when the element was located immediately downstream from the RNA start site without orientation preference. These two elements participate independently in the enhancement of gene expression.

Base Sequence↗

Synthetic parathyroid hormone fragments shortened at the amino terminus stimulate glucose-6-phosphate dehydrogenase activity in the distal renal tubule.

The cytochemical bioassay, using glucose-6-phosphate dehydrogenase (G6PD) activity in the distal convoluted tubule of a guniea pig as an index, is specific and the most sensitive method of evaluating the biological activity of parathyroid hormone (PTH). Using this method, biological activities of the amino- or carboxyl-terminal PTH fragments and analogues, human (h) PTH-(3-34), [Tyr34]hPTH-(7-34)amide(NH2), [Tyr34]hPTH-(13-34)NH2, hPTH-(39-84), hPTH-(51-84), hPTH-(69-84), were tested over a concentration range of 10(-16) to 10(-13) M. In addition, the combined effect of these hormones with human or bovine PTH-(1-84) and the effect of dibutyryl (Bu)2) cAMP were also evaluated. In the 14-min time-course study, amino-terminal PTH fragments and analogues induced cyclic changes of G6PD activity with shorter cycle lengths in higher concentrations and with constant peak heights regardless of the concentrations. Human and bovine PTH-(1-84) showed the same activity on G6PD activation at 6 min. hPTH-(3-34), [Tyr34]hPTH-(7-34)NH2, and [Tyr34]hPTH-(13-34)NH2 were equipotent with PTH-(1-84) on a molar basis, and none of these analogues inhibited PTH-(1-84) even with doses up to 240 times that of PTH-(1-84). Carboxyl-terminal PTH showed no effect. (Bu)2cAMP mimicked the effect of PTH-(1-84) on G6PD activation in time course and dose response. We conclude that the amino terminus is not essential for the biological activity of PTH in the cytochemical bioassay.

Animals↗

Increased urinary excretion of argininosuccinate in type II citrullinemia.

Although argininosuccinate is a product of the catalytic action of deficient argininosuccinate synthetase in citrullinemia, its concentration was found to be elevated in the urine of patients with type II citrullinemia. Urinary argininosuccinate was identified by two methods; its conversions to anhydride by boiling in an acidic solution and to arginine by the enzymatic action of argininosuccinate lyase. Oral administration of citrulline to patients with type II citrullinemia and control subjects increased urinary argininosuccinate levels. These phenomena are consistent with our previous findings on type II citrullinemia (Adv Exp Med Biol 1983;153:63-76,J Clin Biochem Nutr 1986;1:129-142), namely that renal argininosuccinate synthetase which plays a role in arginine synthesis is not deficient in patients with type II citrullinemia; and that serum arginine levels in patients with type II citrullinemia are rather higher than the controls, and increase after the oral administration of citrulline. The organ-specific deficiency of argininosuccinate synthetase in type II citrullinemia is further confirmed by this paper.

Administration, Oral↗

Evaluation of diseased coronary arterial branches by polar representations of thallium-201 rotational myocardial imaging.

The perfusion territories in polar representations of stress Tl-201 rotational myocardial imaging in patients with angina pectoris who had one diseased coronary segment were analyzed. The lesions proximal or distal to the first major septal perforator in left anterior descending arteries were detected by the presence or absence of defects at the base of the anterior septum. Right coronary artery lesions were detected by the presence of defects at the basal posterior septum, in contrast to the preservation of myocardial uptake at this portion in lesions of the left circumflex artery. The specific defect patterns were detected in cases with lesions at the first diagonal, obtuse marginal, and posterolateral branches. Recognition of these defects in the polar maps allows detailed detection of diseased coronary arterial branches.

Adult↗

Cooperation of middle and small T antigens of polyomavirus in transformation of established fibroblast and epithelial-like cell lines.

We have reported recently that small T antigen of polyomavirus stimulates the growth of NIH 3T3 cells beyond their saturation density and induces weak anchorage-independent growth (T. Noda, M. Satake, T. Robins, and Y. Ito, J. Virol. 60:105-113, 1986). We examined whether small T antigen would cooperate with middle T antigen in the in vitro transformation of NIH 3T3 (fibroblasts) and NRK-52E (epitheliallike) cells. The small-T-antigen gene, when cotransfected with the middle-T-antigen gene, had no additional effect on the efficiency or size of dense foci formation induced by the middle-T-antigen gene on a monolayer of NIH 3T3 cells. However, the small-T-antigen gene dramatically increased the rate of growth of NIH 3T3 cells transformed by middle T antigen in semisolid medium. Introduction of the small-T-antigen gene into middle-T-antigen-transformed cells did not disturb the integrated middle-T gene, alter expression of the middle-T gene, or enhance middle-T-antigen-associated tyrosine protein kinase activity. For NRK-52E cells, the expression of middle T antigen alone resulted in small, slow-growing foci on a monolayer. These cells did not show anchorage-independent growth, despite the fact that middle-T-antigen-associated tyrosine protein kinase activity was clearly detected in these cells. NRK-52E cells expressing both middle and small T antigens formed faster growing foci on a monolayer than middle-T-antigen-expressing cells did and grew in semisolid medium, even when the amounts of middle T antigen and its associated kinase activities were lower than those of middle-T-antigen-expressing cells. We conclude that small T antigen cooperates with middle T antigen in the in vitro transformation of established cell lines of fibroblast and epitheliallike cells, that it does not share the middle-T-antigen function even though they are structurally related, and that it has a significantly more important role in the transformation of NRK-52E cells than that of NIH 3T3 cells.

Animals↗

Molecular basis of enzyme abnormalities in urea cycle disorders. With special reference to citrullinemia and argininosuccinic aciduria.

This paper deals with enzymological, immunochemical and molecular genetic analyses of citrullinemia and argininosuccinic aciduria. Citrullinemia has been classified by Saheki et al. [J. inher. Metab. Dis. 8: 155-156, 1985] into three types from the properties of the deficient argininosuccinate synthetase (ASS) of the patients. Analysis of hepatic mRNA coding for ASS revealed certain characteristics in type II and III citrullinemic patients whose hepatic ASS protein was low. A newly developed enzyme-linked immunosorbent assay (ELISA) of argininosuccinate lyase (ASL) protein showed that 8 out of ten cases of argininosuccinic aciduria had no detectable ASL protein in the liver, erythrocytes, cultured skin fibroblasts or cultured amniocytes.

Amino Acid Metabolism, Inborn Errors↗

[Study of quantitative evaluation of liver volume and accumulation rate of radioactive agent with single photon emission computed tomography].

The quantitative evaluation on measurement of liver volume and the hepatic accumulation rate of the radioactive agent were studied with respect to body constitution, background activity and splenic consumption rate, using single photon emission computed tomography (SPECT). The optical cut-off level for liver volume determination was proved to be reasonable as 35%. The background less than 5% had no influence to their clinical estimation with the error of less than 1.6%. The estimation of liver volume was mostly influenced by the splenic activity. When the splenic activity was increased two times of the hepatic activity, the liver volume was determined as 4.2% larger. Calculated counts by SPECT was well correlated with the hepatic activity. This study proved that SPECT was useful for the quantitative evaluation of the liver volume and the hepatic accumulation rate.

Background Radiation↗

[A case report of an advanced ovarian cancer (stage T4) treated with a total amount of 1815 mg of CDDP].

A case is reported of a 34-year-old female who complained of an adult head-sized tumor in the pelvis and was treated with a high dose of CDDP. On the first look operation, it was found impossible to perform reduction surgery because of severe adhesion and peritonitis carcinomatosa. To introduce a high concentration of an anti-cancer agent into the tumor tissue, we administered CDDP intravenously, intraperitoneally and intra-arterially to the total amount of 1815 mg. After this high dose combination chemotherapy, a second look operation was performed and the tumor was seen to be reduced. The patient is now in remission and is being followed up as an out-patient. The clinical course of this case had decided for us which route would be the most effective and would have the least side effect, also, how much of a dosage can be administered as a maximum adoptive dose of an anti-cancer agent, and what kind of a second-line chemotherapy is effective against resistant cancer cells.

Adult↗

[Intraperitoneal high-dose cisplatinum chemotherapy (CDDP-ip) in patients with carcinomatous peritonitis].

Immediately after CDDP-ip, the level of free Pt in ascites reached nearly 100 micrograms/ml, and the AUC (area under the curve) for ascites was 20-140 times greater than that for serum. The free Pt in serum following CDDP-ip administration was detected for several hours, and interestingly, the AUC for serum after ip therapy was 0.4-2.2 times greater than that after iv therapy. As a result, free Pt was found to act on cancer cells in the abdominal cavity directly at a high concentration. At the same time, the possibility of an antitumor effect from the vascular side of the tumor was also suggested. On the other hand, cases of ovarian cancer had various levels of peritoneal clearance (CLp), which depended on the severity of their carcinomatous peritonitis. The CLp had a great influence on the peak plasma concentration and on the AUC of free Pt in serum. In particular, the peak plasma concentration produced by CDDP-ip was 40-80% of the plasma concentration produced by CDDP-iv. These findings indicate that high-dose CDDP-ip is possibly effective and useful for advanced ovarian cancer, producing only very mild side effects.

Ascitic Fluid↗