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Biomedical subjects

R Goto

Publications and source records attributed to R Goto.

At least 127 records · Page 7Linked to original sources
PubMed1987

Analysis of reducing sugars as their chromophoric hydrazones by high-performance liquid chromatography.

A chromophoric hydrazide, 4'-N,N-dimethylamino-4-azobenzene sulfonyl hydrazide (DABS-hydrazide), was prepared from 4'-N,N-dimethylamino-4-azobenzene sulfonyl chloride by reaction with hydrazine. Reducing sugars were derivatized with DABS-hydrazide at 50 degrees C for 120 min. The chromophoric hydrazones were separated by reversed-phase HPLC isocratically using a short column (4.6 X 50 mm) and 0.08 M acetic acid-acetone as an eluant with no sample pretreatment and were quantitated at the picomole level. This method was applied to the sugar analysis of 5 micrograms of glycoproteins. Dansyl hydrazide derivatives of sugars were also separated by this HPLC system.

Carbohydrates↗
PubMed1987

Isolation and characterization of agglutinins from the hemolymph of an acorn barnacle, Megabalanus volcano.

Two agglutinins, MVA-1 and MVA-2, were isolated from the hemolymph of the acorn barnacle, Megabalanus volcano. They agglutinated human erythrocytes irrespective of the ABO blood group and also rabbit and sheep blood cells. Lactose and fetuin strongly inhibited the hemagglutinating activity. D-galactose, D-arabinose and N-acetylneuraminic acid were also moderate inhibitors. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis, both MVA-1 and MVA-2 gave a single band corresponding to 38,000 daltons. It split into one major band with a molecular weight of 23,000 in the presence of 2-mercaptoethanol. The two agglutinins showed the same apparent molecular weight of 116,000 by gel filtration. In isoelectric focusing MVA-1 showed one band at pH 4.8, whereas MVA-2 gave a main band at pH 4.4 with few faint ones in the range between pH 4.0 and 4.8. The agglutinins were glycoproteins containing D-mannose and L-fucose as carbohydrate components. No precipitation reaction was observed in Ouchterlony immuno-diffusion tests using rabbit antisera against the agglutinins from the phylogenetically related Megabalanus rosa.

Amino Acids↗
PubMed1987

Tumor accumulation of D-selenomethionine-75Se in tumor-bearing mice.

The radioactivity distribution of 75Se-labeled D-selenomethionine (D-SeMet-75Se) was investigated in tumor-bearing mice in order to develop a new radioactive diagnostic agent. D-SeMet-75Se was enzymatically prepared from commercially available L-selenomethionine-75Se (L-SeMet-75Se) by using amino acid racemase and immobilized L-amino acid oxidase. No difference between D- and L-SeMet-75Se was found in the excretion rate into urine and feces in normal mice within 48 h after administration. The in vivo uptake of D-SeMet-75Se in both Ehrlich solid tumor and sarcoma-180 solid tumor was several times higher than that of L-SeMet-75Se but the uptake of D- and L-SeMet-75Se were similar in the pancreas. These results indicated that D-SeMet-75Se might be useful as a tumor-imaging agent. In vitro experiments on Ehrlich ascites tumor cells showed that D-SeMet-75Se was incorporated into the tumor cells by a Na+-dependent active transport system similar to L-SeMet-75Se and that a transport mechanism specific for D-SeMet-75Se might be present in tumor cells in addition to a transport system common to both D- and L-forms.

2,4-Dinitrophenol↗
PubMed1987

Carnitine deficiency in lysinuric protein intolerance: lysine-sparing effect of carnitine.

Plasma carnitine deficiency (41% of normal control) was found in a 9 year-old boy with lysinuric protein intolerance. Following oral carnitine administration, the plasma level of lysine as well as carnitine has significantly increased (p less than 0.05). His well-being seemed to have improved on this substitutive remedy. Hitherto unrevealed these findings on LPI indicate that carnitine has a lysine-sparing effect and suggest that there might be a biosynthetic pathway of carnitine directly from free lysine in human.

Amino Acid Metabolism, Inborn Errors↗
PubMed1984

Analysis of the B-G antigens of the chicken MHC by two-dimensional gel electrophoresis.

The B-G antigens of the chicken major histocompatibility complex (MHC) have been analyzed by high resolution two-dimensional (2-D) gel electrophoresis. Monoclonal antibodies recognizing a widely shared B-G determinant were used for immunoprecipitating the B-G antigens from radioiodinated, detergent-solubilized erythrocyte membrane preparations. The B-G antigens produce a variety of patterns on 2-D gels. The number of polypeptides within a B-G pattern varies among haplotypes from single polypeptide arrays showing slight microheterogeneity to complex patterns which contain as many as four or five polypeptide arrays differing in relative mobility and isoelectric point. Many of the patterns, but not all, include a polypeptide of Mr = 48 kd focusing near pH 6.9. At present it is not understood whether the multiple polypeptides within some B-G patterns represent the expression of multiple B-G genes or whether they are the result of modifications of single gene products during biosynthetic processing. 2-D gel analyses were also used to confirm the assignment of the same B-G haplotype in several different inbred flocks and the fate of the B-G antigens in two B system recombinant haplotypes. The 2-D gel patterns of these highly polymorphic antigens provide evidence for a complexity of the B-G locus not previously demonstrated. This technique may serve to define more objectively the diverse chicken MHC haplotypes which are now recognized and characterized only by serological techniques using alloantisera and monoclonal antibodies with varying cross-reactivities.

Animals↗
PubMed1984

Stimulating effects of inosine, uridine and glutamine on the tissue distribution of radioactive D-leucine in tumor bearing mice.

This experiment was carried out in search for stimulators of the in vivo uptake of D- and L-leucine by tumor and pancreas for the possible application to gamma-emitter labeled amino acids in nuclear medical diagnosis. Inosine, uridine, and glutamine which are stimulators of the in vitro incorporation of radioactive L-amino acids into some tumor cells significantly enhanced the uptake of D-leucine into the pancreas, while in Ehrlich solid tumor only a little if any increase was observed. Of the compounds tested inosine showed the highest stimulation of pancreas uptake in the range of doses used, resulting in the best pancreas-to-liver concentration ratio, a factor of significant consideration for pancreas imaging. The uptake of L-leucine by the tumor and pancreas was little affected by these compounds.

Animals↗
PubMed1984

Biological evaluation of radiolabeled D-methionine as a parent compound in potential nuclear imaging.

Based on the high radioactivity uptake of some 14C-labeled D-amino acids in tumors and pancreas of mice, this investigation was undertaken to ascertain possible usefulness of radioactive D-methionine as a nuclear imaging agent. Radioactivity derived from D-[3,4-14C]-methionine in Ehrlich solid tumor was approximately three times higher than that from the L-isomer, but was the same as for mouse pancreas. Excretion rate of the radioactivity of D-[14C]-methionine into urine was approximately two times faster than that of the L-isomer. As compared with two potential imaging agents, 1-aminocyclopentane-1-carboxylic acid and alpha-aminoisobutyric acid, D-methionine showed almost the same radioactivity biodistribution in tumor and pancreas. These results suggest potential for D-methionine as a mother compound for use in tumor and pancreas imaging.

Animals↗