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Biomedical subjects

S Hara

Publications and source records attributed to S Hara.

At least 541 records · Page 30Linked to original sources
PubMed1985

Isolation, primary structure and synthesis of heat-stable enterotoxin produced by Yersinia enterocolitica.

Five heat-stable enterotoxins were isolated from the culture supernatant of Yersinia enterocolitica and purified to homogeneity by DEAE-Sephacel and high-performance liquid chromatographies. They caused acute fluid accumulation in the intestine of suckling mice. The amino acid sequence of one of the enterotoxins was determined to be Ser-Ser-Asp-Trp-Asp-Cys-Cys-Asp-Val-Cys-Cys-Asn-Pro-Ala-Cys-Ala-Gly-Cys, by Edman degradation of its pyridylethylated derivative and a combination of fast atom bombardment mass spectrometry and carboxypeptidase B digestion. This structure was unambiguously confirmed by chemical synthesis. The other enterotoxins had longer or shorter amino acid sequences at their N termini, but the same sequence at their C termini. The six half-cystine residues formed intramolecular disulfide linkages, as shown by measurement of the molecular masses of the enterotoxins by fast atom bombardment mass spectrometry. The sequence of 13 amino acid residues at the C terminus showed similarity to those of heat-stable enterotoxins isolated from enterotoxigenic Escherichia coli [Aimoto, S. et al. (1982) Eur. J. Biochem. 129, 257-263; Takao, T. et al. (1983) FEBS Lett. 152, 1-5] suggesting that these similar sequences are related to the common biological and immunological properties of enterotoxins produced by Y. enterocolitica and enterotoxigenic E. coli.

Amino Acid Sequence↗
PubMed1985

Efficient chromatographic fractionation of steroids in human serum through regulation of liquid--liquid distribution ratios.

To improve the clean-up process in the analysis of biological fluid constituents, an efficient liquid--liquid distribution system was developed. Closed-bed columns containing fine diatomaceous earth granules were prepared by slurry packing for the fractionation of steroid hormones in human serum before quantitative assay by liquid chromatography or radioimmunoassay. Four columns were connected to construct the aqueous liquid--liquid chromatography--fractionation system. The first was coated with neutral water for distribution of serum, the second was weakly alkaline with sodium hydrogen carbonate for extrusion of strong acidic components, and the third was strongly alkaline with sodium hydroxide to capture oestrogens. The final column was acidic with sulphuric acid to remove basic components. Optimization of the stepwise gradient solvents was achieved on the basis of the results of a linear relationship between the logarithms of the capacity ratios and solvent composition determined from an analytical run. Neutral steroid hormones added to serum were eluted from the column system by a stepwise gradient elution technique to obtain first very non-polar materials, then progesterone and testosterone, and finally to extract the corticosteroids. Phenolic oestrogens were recovered from the strong alkaline column with a mobile phase solvent after the pH of the stationary phase had been adjusted with a phase transfer neutralizer. The fractional constituents were purified and enriched. This procedure was used to determine Solu-medrol, an acidic corticosteroid drug, in human serum.

Chromatography, Liquid↗
PubMed1985

Essential structure for full enterotoxigenic activity of heat-stable enterotoxin produced by enterotoxigenic Escherichia coli.

Several analogues of heat-stable enterotoxins (STh and STp) produced by enterotoxigenic Escherichia coli were synthesized. Peptides (STh[6-18] and STp[5-17]) consisting of 13 amino acid residues from the Cys residue near the N-terminus to the Cys residue near the C-terminus and linked by three disulfide bonds had the same biological and immunological properties as native STh and STp, respectively. The results indicated that the sequence with the 13 amino acid residues and three disulfide linkages is essential for full biological activity of ST.

Amino Acid Sequence↗
PubMed1985

Decreased transfer of oligosaccharide from oligosaccharide-lipid to protein acceptors in regenerating rat liver.

The transfer of [14C]glucose from UDP-[14C]glucose to lipid intermediates and glycoproteins was decreased in regenerating rat liver microsomes 24 h after partial hepatectomy. In regenerating liver microsomes, the concentration of free dolichyl phosphate (Dol-P) was significantly decreased. However, it was only about 10% of total Dol-P, which was not significantly changed. On the addition of exogenous Dol-P, the transfer of [14C]glucose to glycoproteins was still decreased, while the decrease of the transfer to lipid intermediates was no longer observed. These results suggest that the glycoprotein synthesis is not regulated by the amount of Dol-P in regenerating liver microsomes. Oligosaccharide obtained from [14C]glucosyl-oligosaccharide-lipid was not distinguishable between regenerating liver and control by paper chromatography. The oligosaccharide transfer to protein in microsomes was compared by using [14C]glucosyl-oligosaccharide-lipid as oligosaccharide donor. The transfer of oligosaccharide to endogenous proteins decreased to 77% of control in regenerating liver and the transfer to exogenously added denatured alpha-lactalbumin decreased to 59% of control. Therefore, it is unlikely that the acceptor capacity of endogenous protein is decreased in regenerating liver. Neither the change in oligosaccharide-lipid under the condition for oligosaccharide transfer assay nor the stability of oligosaccharide transferase was different between regenerating liver and control. These results strongly suggest that the decrease in the activity of the oligosaccharide transferase in microsomes causes the decrease of glycoprotein synthesis in regenerating liver, which was shown in our previous studies.

Animals↗
PubMed1985

Diagnosis and operation for locally recurrent rectal cancer.

Local recurrence of rectal cancer following abdominoperineal resection is rarely amenable to limited resection. Six patients with deeply invading recurrent lesions had pelvic exenteration combined with sacral resection. This procedure seems a reasonable treatment for palliation and the chance of cure in selected patients. In order to select good candidates for this extensive procedure, carcinoembryonic antigen (CEA) assays and the diagnosis of locally recurrent tumor with pelvic computed tomography (CT) were evaluated. CEA assay is valuable for diagnosing most recurrent rectal cancers, but it is inadequate for early detection. A high CEA level often indicates extrapelvic tumor spread. CT examination is very valuable for the early detection and localization of recurrence in relation to pelvic structures.

Adenocarcinoma↗
PubMed1985

Amino acid sequence of Streptomyces metallo-proteinase inhibitor from Streptomyces nigrescens TK-23.

Streptomyces Metallo-Proteinase Inhibitor (S-MPI) consists of 102 amino acid residues, including one methionine and two disulfide bridges. The complete amino acid sequence of S-MPI, including two disulfide bridges, was determined by sequencing of tryptic and chymotryptic peptides of two fragments obtained by cyanogen bromide cleavage followed by reduction and S-pyridylethylation of the protein. Incubation of the inhibitor with thermolysin slowly cleaved one peptide bond, Cys(64)-Val(65), which might be a reactive site of S-MPI.

Amino Acid Sequence↗
PubMed1985

Amino acid sequence of protein alpha-amylase inhibitor from Streptomyces griseosporeus YM-25.

The amino acid sequence of a protein alpha-amylase inhibitor from Streptomyces griseosporeus YM-25 (Haim II), which consists of 77 amino acid residues, including two disulfide bridges, was determined by conventional methods. One of the disulfide bridges was found to be located between Cys(6) and Cys(22), and the other between Cys(40) and Cys(67) from the results of structure analyses of the two cystine-containing peptides obtained from the thermolysin digest of the native inhibitor.

Amino Acid Sequence↗
PubMed1985

Comparative study on amino acid sequences of Kunitz-type soybean trypsin inhibitors, Tia, Tib, and Tic.

The amino acid sequences of three variants of the Kunitz-type trypsin inhibitors, Tia, Tib, and Tic, obtained from some cultivars of soybean were determined by conventional methods. All three inhibitors consisted of 181 amino acid residues. The differences in the amino acid sequences are as follows: Tia E12 G55 Y62 H71 S74 M114 L120 P137 L176; Tib S F N R V I T V; Tic E. The amino acid sequences of Pro(60)-Ser(61) and Asp(154)-Asp(155)-Gly(156)-His(157) of Tia reported previously (Koide & Ikenaka (1973) Eur. J. Biochem. 32, 417-431) were amended to Ser(60)-Pro(61) and His(154)-Asp-Asp-Gly(157), respectively.

Amino Acid Sequence↗
PubMed1985

[Measurement of transmucosal potential difference before and after gastric mucosal injury in dogs].

Three mongrel dogs (12-14 kg BW) were used to measure the transmucosal gastric potential difference (PD) after gastric injury by electric thermocautery under endoscopic control. The parameters obtained after mathematical fitting of the experimental data to the inverse Batemen function reflected the characteristics, surface and depth of the mucosa injury. These results suggest that a calculated gastric response (GR) is appropriate to evaluate the intensity of gastric mucosal injury.

Animals↗
PubMed1985

[Reactivation of prostatic cancer and chemotherapy in reactivated prostatic cancer].

From January, 1960 to March, 1984, we studied 65 cases of prostatic cancer resistant to endocrine therapy. Treatment with ifosfamide or combination chemotherapy with vincristine, ifosfamide and peplomycin was performed in some of the 65 cases above mentioned. More cases were systemic reactivation than local reactivation. Poorly differentiated cancer accounted for the majority of the reactivated cancer. Concerning adjacent effects, treatment with ifosfamide was superior to combination chemotherapy. There was no difference between the distant effects of both chemotherapies. The patients with no effects showed predominance of pathologically low differentiated cell type. The 6-month survival rate of patients with chemotherapy was significantly higher than that of patients with other therapies. Toxicities of chemotherapies were leucopenia, digestive disturbances and falling out of hair. Hematuria and pulmonary fibrosis occurred in some cases.

Aged↗
PubMed1985

Enzymes in ornithine-proline metabolic pathway in bovine lens.

Various enzyme activities related to ornithine metabolism were studied using bovine lenses, ie, ornithine ketoacid transaminase, delta-1-pyrroline-5-carboxylate reductase, and delta-1-pyrroline-5-carboxylate dehydrogenase. Ornithine ketoacid transaminase activity was found in the lens epithelium; delta-1-pyrroline-5-carboxylate reductase activity was high in both lens epithelium and cortex plus nucleus; delta-1-pyrroline-5-carboxylate dehydrogenase activity was negligible in either lens epithelium or cortex plus nucleus. These results suggest that in the bovine lens ornithine is converted to proline by the cooperative action of ornithine ketoacid transaminase and delta-1-pyrroline-5-carboxylate reductase.

1-Pyrroline-5-Carboxylate Dehydrogenase↗