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Biomedical subjects

Y Muto

Publications and source records attributed to Y Muto.

At least 487 records · Page 27Linked to original sources
PubMed1979

Demonstration of a novel molecular species in chick embryo brain: cellular retinol-binding protein, F-type.

By sucrose density gradient sedimentation analysis, a cytosol component of small molecular size which bound 3H-retinoic acid was detected in the chick embryo brain, exhibiting a peak on day 14 (7 days before hatching). In general, cellular retinol-binding protein (CRBP) and cellular retinoic acid-binding protein (CRABP) have been distinguished by showing binding specificity for retinol or retinoic acid, respectively. However, the component found in embryo brain cytosol exhibited binding affinity for both retinol and retinoic acid, being similar in less ligand-specificity to CRBP (F) which was originally recognized in fish eye cytosol. Moreover, the component also showed a lack of binding affinity for prealbumin (PA), excluding the possibility that chicken plasma RBP was contaminated in the cytosol. These findings strongly suggest that a distinct molecular species of cellular binding protein for vitamin A exists in the brain cytosol of a developing chick embryo.

Animals↗
PubMed1979

Demonstration of a novel cellular retinol-binding protein, F-type, in hepatocellular carcinoma.

Vitamin A level and the cytosol-binding proteins specific for vitamin A ere studied in human tumor and its surrounding tissue. The tissues examined were 10 hepatocellular carcinomas which were surgically removed, 4 other malignant tumors (2 metastatic liver cancer and one each of gastric cancer and glioma), and 3 human fetal livers. Compared with surrounding tissues, considerable decrease of vitamin A content was observed in the hepatocellular carcinoma suggesting local deficient state of the vitamin. In addition to cellular retinol-binding protein (CRBP) and retinoic acid-binding protein (CRABP), a new molecular species having affinity for both retinol and retinoic acid was detected in the cytosols obtained from hepatocellular carcinoma as well as glioma by means of gel filtration on Sephadex G-75. With regard to ligand specificity, the protein was found to be similar to cellular retinol-binding protein, F-type or CRBP(F) which was originally recognized in the fish eye cytosol. Since the protein was also demonstrated in human fetal liver, CRBP(F) is considered to be an oncofetal protein in nature. The present study further revealed that CRBP(F) was detected in 80% of hepatocellular carcinoma (whereas plasma alpha-fetoprotein was significantly elevated only in 50%), and hepatocellular carcinoma contained CRBP(F) in a larger amount than CRABP.

Adult↗
PubMed1978

Serial studies on in vitro colony formation in patients with acute leukemia in relation to the maintenance of remission.

For the purpose of preventing a relapse of acute leukemia which is currently the major problem in the successful treatment of the disease, repeated consolidation or intensification therapy during the first year following remission is important. To evaluate these therapies, we investigated the serial changes in CFU-C's of the marrow cells from 12 patients with acute nonlymphocytic leukemia in remission and tried to estimate the relationship between the intensity of consolidation or intensification therapy and the duration of remission, utilizing the degree of reduction in CFU-C's seven days after these treatments as an indicator. As a result, after 21 out of 22 courses of therapy where CFU-C's were reduced significantly after the therapy, the patients were still in remission at the time of the next intensificiation therapy (at most for about 100 days). On the other hand, after five out of ten courses where CFU-C's were not reduced significantly, the patients were in relapse at the time of the next intensification therapy. From these results, it may be inferred that cases whose CFU-C's are not reduced significantly should be treated intensively again within a short period.

Acute Disease↗
PubMed1978

A case of intrarenal artery stenosis associated with erythrocytosis.

A case of erythrocytosis with increased plasma erythropoietin level was reported. Peripheral leucocytes and thrombocytes were normal. No splenomegaly was detected. Studies to find underlying disorders causing increased plasma erythropoietin level and erythrocytosis revealed no abnormalities except for the thickened and tortuous interlobular and afferent arteries in the kidney. This change was suggested as the cause of erythrocytosis found in this case.

Adult↗
PubMed1978

Effects of exogenous retinol and retinoic acid on the biosynthesis of 14C-mannose labelled glycolipids and glycoproteins in rat liver.

Studies were conducted to investigate the in vivo and in vitro effects of retinol and retinoic acid on the synthesis of mannolipids and mannopeptides in rat liver. The incorporation of 14C-mannose into glycolipids and glycoproteins showed a decrease in vitamin A-depleted rats as compared with vitamin A-fed rats. By means of DEAE-cellulose, silicic acid and thin-layer chromatography, the mannose-containing lipids were separated into mannosyl retinyl phosphate (MRP, Rf 0.2) and dolichyl mannosyl phosphate (DMP, Rf 0.4), respectively. A rapid increase in the synthesis of labelled MRP was observed, exhibiting a peak between 25 and 60 min after intraperitoneal administration of retinol to vitamin A-depleted rats. Similarly, administration of retinoic acid brought about elevation of 14C-mannolipid (Rf 0.2) synthesis with a peak at 60 min after injection. On the other hand, the incorporation of 14C-mannose into DMP (Rf 0.4) remained unchanged by such treatment. In vitro addition of retinyl phosphate, but not retinoyl phosphate, markedly stimulated the synthesis of 14C-mannolipid (Rf 0.2), using crude membrane of rat liver and GDP-14C-mannose as the donor. These findings strongly suggest that not only retinol but also retinoic acid plays an important biological role in mannosyl transfer reaction in rat liver. However, the molecular participation of a metabolite of retinoic acid in the formation of a mannolipid and the structure of such a metabolite remain to be established.

Animals↗