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Biomedical subjects

T Murase

Publications and source records attributed to T Murase.

At least 451 records · Page 25Linked to original sources
PubMed1981

Inappropriate secretion of antidiuretic hormone in nude mice bearing a human bronchogenic oat cell carcinoma.

A 58-year-old man with bronchogenic oat cell carcinoma developed a typical syndrome of inappropriate secretion of antidiuretic hormone. The tumor tissue obtained at autopsy had been serially transplanted in nude mice for more than four years with 20 passages. The levels of vasopressin were remarkably increased in the plasma of nude mice bearing this tumor [24.4 +/- 18.3 (S.D.) pg/ml, n = 3] as well as in the tumor tissues ]134.3 +/- 72.2 ng/g, n = 3]. Furthermore, human nicotine-stimulated neurophysin was detected in both plasma and tumor tissues (7.4 +/- 3.7 ng/ml, n = 3, and 2.28 +/- 0.90 micrograms/g, n = 3, respectively). On ad libitum intake of water, nude mice bearing this tumor excreted significantly less urine with higher sodium concentration than did controls, but serum sodium concentrations did not differ from those of controls. When tumor-bearing mice were hydrated with 2 ml of water twice a day i.p., their diuretic response was found to be suppressed in parallel with the tumor size. However, these mice did not become hyponatremic because they drank less water. When a larger amount of water was loaded which could not be compensated by restriction of water drinking, serum sodium concentrations were markedly decreased. On the basis of these results, the lung cancer, when transplanted into nude mice, produced and secreted its own antidiuretic hormone, which induced inappropriate secretion of antidiuretic hormone in the mice. These mice may provide a useful experimental model for the study of excessive secretion of antidiuretic hormone and associated pathophysiological disorders.

Animals↗
PubMed1980

Decline of postheparin plasma lipoprotein lipase in acromegalic patients.

Lipoprotein lipase and hepatic triglyceride lipase in postheparin plasma were measured in seven patients with active acromegaly by an immunochemical method utilizing antiserum prepared against hepatic triglyceride lipase. A mild or moderate hypertriglyceridemia was shown, with plasma triglyceride concentrations between 156 and 544 mg/dl. Lipoprotein lipase was found to be decreased in all patients (p less than 0.001). Hepatic triglyceride lipase was also low in these patients (p less than 0.001). We speculate that acromegalic hypertriglyceridemia is mediated, at least in part, by the decline in lipoprotein lipase and possibly by the decline in hepatic triglyceride lipase activities.

Acromegaly↗
PubMed1980

A selective decline of postheparin plasma hepatic triglyceride lipase in hypothyroid rats.

The present study aimed to define the effect of thyroid status on two postheparin plasma lipases, i.e., lipoprotein lipase and hepatic triglyceride lipase. Rats with hypo- and hyperthyroidism were used for this purpose. Separate measurement of these two lipases was done by an immunochemical method utilizing antiserum specific to hepatic triglyceride lipase. The 5-wk thyroidectomized, hypothyroid rats had normal plasma concentrations of both triglyceride and cholesterol. These rats showed a selective decline in the activity of postheparin plasma hepatic triglyceride lipase with normal lipoprotein lipase activity. The rats made thyrotoxic by thyroxine treatment had normal plasma levels of both triglyceride and cholesterol. These rats showed normal activities of both hepatic triglyceride lipase and lipoprotein lipase. The observed finding of a selective decline of hepatic triglyceride lipase in hypothyroid rats is discussed in connection with the possible function of this enzyme in lipoprotein metabolism.

Animals↗
PubMed1980

Transitional cell carcinoma of the bladder in patients with renal pelvic and ureteral cancer.

We reviewed 41 cases of transitional cell carcinoma of the renal pelvis and ureter with special reference to the coexistence or subsequent development of bladder cancer. Bladder cancer was associated with an upper urinary tract neoplasm in 20 of the 41 cases (48 per cent). Most of these patients (15 of 20) were treated by radical total cystectomy of 1-stage nephroureterocystectomy. The incidence of ureteral stump cancer after nephrectomy alone or incomplete nephroureterectomy was 64 per cent (7 of 11 patients). Twelve surgically removed specimens of the renal pelvis, ureter and/or bladder were examined extensively for the histological association of pre-neoplastic disease, such as atypical hyperplasia and carcinoma in situ. Every specimen had these changes of the urothelium adjacent to and remote from obvious tumors.

Adolescent↗
PubMed1979

A selective deficiency of hepatic triacylglycerol lipase in guinea pigs.

The properties of postheparin plasma triacylglycerol-hydrolyzing enzymes were investigated in guinea pig and rat. In rat, lipoprotein lipase and hepatic triacylglycerol lipase were separated on a heparin-Sepharose affinity chromatography. In postheparin plasma of guinea pig, however, hepatic triacylglycerol lipase was almost completely absent, while lipoprotein lipase was present. Hepatic triacylglycerol lipase was also deficient in the liver tissue extract of guinea pig. Plasma lipoprotein compositions of high-fat fed and control guinea pigs were analyzed. One of the outstanding changes found in high-fat fed animals was the presence of chylomicronemia. One guinea pig showed gross hyperlipemia with triacylglycerol concentrations of 2715 mg/100 ml. Plasma triacylglycerol concentrations of each lipoprotein fraction of very low density, intermediate density, low density and high density lipoproteins from high-fat fed animals were almost the same as those of the corresponding lipoprotein fractions from controls. Discussion was focused on the development of chylomicronemia in relation to the defects of triacylglycerol-hydrolyzing enzyme systems in this animal.

Animals↗
PubMed1978

The interaction of apolipoproteins with lecithin:cholesterol acyltransferase.

The rate of lecithin:cholesterole acyltransferase reaction was measured in a cholesterol-containing single bilayer lecithin vesicle system. ApolipoproteinA-I (apoA-I) activated the enzyme by itself; the other components of apolipoproteins of high density lipoproteins (HDL) (rho = 1.08--1.2 g/cm3), or rabbit serum gamma globulin inhibited the reaction. The reaction which was activated by pure apoA-I was strongly inhibited by anti-apoA-I antibody. Quantitative analysis of the results showed that the lecithin:cholesterol acyltransferase reaction was activated by the binding of apoA-I to the surface of lipid substrates. The rate of the lecithin:cholesterol acyltransferase-catalyzed reaction was strictly proportional to the surface density of apoA-I. The inhibition was due to the decrease of the amount of apoA-I on the lipid surface, either through competitive exclusion by apoA-II or by other proteins, or through specific extraction with antibody. The presence of components of apoHDL, other than apoA-I, prevented the inhibitory action of anti-apoA-I antibody.

Antigen-Antibody Reactions↗
PubMed1977

Phosphatidylcholine substrate specificity of lecithin: cholestrol acyltransferase-in high density lipoproteins and in lipids dispersions.

Lecithin: cholesterol acyltransferase (LCAT) was more highly activated by apolipoprotein A-I (apoA-I) with dimyristoyl phosphatidylcholine (DMPC) than with dilinoleoyl phosphatidylcholine (DLPC) when lipid dispersion of cholesterol and each phosphatidylcholine was used as a substrate. When the enzyme reactions were activated by whole apolipoproteins of high density lipoproteins (HDL), DLPC was more available to the LCAT reaction than DMPC with high concentrations of apoHDL in an incubation mixture. However, no detectable enzyme reaction was observed with dipalmitoyl phosphatidylcholine (DPPC) under both conditions. On the other hand, all of these phosphatidylcholines acted as substrates of LCAT when they were incorporated into HDL coupled to Sepharose. The order of their relative reactivities to cholesterol was DMPC, DPPC, AND DLPC under the conditions used.

Apolipoproteins↗