Search PubMed⌕ Search

Biomedical subjects

T Terada

Publications and source records attributed to T Terada.

At least 505 records · Page 28Linked to original sources
PubMed1983

Studies on pharmacological activation of human serum IgG by chemical modification and active subfragments. I. Induction of anti-ulcerogenic activity by chemical cleavage of interchain disulfide bonds in human IgG and properties of active subfragments.

Commercially available human IgG (native IgG) was passed through a DEAE cellulose column. Two fractions (Fr. I and Fr. II), responding equally against the anti-human IgG antibody were obtained. The carboxamide-methylated H and L chains from both fractions showed remarkable inhibitory activities on both the gastric ulceration and the gastric juice secretion in pylorus-ligated rats. The carboxamide-methylated L chain of rat IgG was also effective, while none of the human native IgG, Fr. I or Fr. II showed any effect. The reduction and the following alkylation of the interchain disulfide bonds were necessary for the induction of the biological activities of human IgG. Sulfonation of human IgG failed to induce the activities. Although the gastric acid secretion was clearly reduced by the administration of Fr. I-L (alkylated L chain of Fr. I), the gastric mucosal blood flow was not affected.

Alkylation↗
PubMed1983

Studies on pharmacological activation of human serum IgG by chemical modification and active subfragments. II. Inhibitory effects of carboxamide-methylated L chain from human serum IgG on various ulcer models and its inhibition mechanism.

In view of the strong inhibitory effects of the carboxamide-methylated L chain (Fr. I-L) from human IgG on gastric ulceration and juice secretion, we carried out various experiments to clarify the mechanism of its action and obtained the following results. Fr. I-L inhibited the gastric ulceration induced by phenylbutazone or aspirin in rats, but no appreciable effect was observed on stress or acetic acid ulceration. The distribution of 14C-labelled Fr. I-L increased particularly in the stomach mucous membrane of rats after the intravenous or intraperitoneal administration. The hexosamine content in the gastric mucous membrane, reduced by the treatment with phenylbutazone, aspirin or pylorus-ligation, was recovered by the administration of Fr. I-L to an intact level. The high total of hexosamine levels found in the gastric juice after aspirin treatment or pylorus-ligation were decreased by the injection of Fr. I-L or cimetidine. The histochemical observation revealed that the concomitant administration of Fr. I-L with phenylbutazone or aspirin prevented the abolishment of Hematoxylin-Eosin, Periodic Acid Schiff and Alcian Blue staining polysaccharides from the stomach epithelial cells.

Animals↗
PubMed1983

Oxygen consumption rate as a measurement of freeze-induced damage to chicken spermatozoa.

The present study was conducted to determine if oxygen consumption rate of postthaw spermatozoa could be used as the indicator of freeze-induced damage. Pooled semen was diluted fourfold with 5.7% glucose solution containing various levels of glycerol or N-methylformamide for freezing by the pelleting method. Sperm motility and oxygen consumption rate were determined after thawing the samples at 37 C. 1) The maximum motility and oxygen consumption rate of postthaw spermatozoa were observed at 10 and 7% glycerol, respectively. However, no significant differences existed among semen samples diluted in 7, 10, and 15% glycerol. 2) The motility and oxygen consumption rate of spermatozoa frozen with 6 to 9% of N-methylformamide were higher than those of spermatozoa frozen with 0, 3, 12, or 15%. 3) A highly significant positive correlation was observed between motility and oxygen consumption rate immediately after thawing and also after 10 min incubation at 20 C with either cryoprotectant. 4) The polarographic measurement of oxygen consumption rate of postthaw spermatozoa appeared to be a reliable method for evaluating freeze-induced damage to chicken spermatozoa.

Animals↗
PubMed1982

Caroli's disease in congenital hepatic fibrosis and infantile polycystic disease.

Two of three patients with infantile polycystic disease and all three patients with congenital hepatic fibrosis revealed multiple gross cystic dilatation of the intrahepatic biliary tree, referred to as Caroli's disease. All three patients with congenital hepatic fibrosis showed recurrent cholangitis related to coexisting Caroli's disease, and two of them died of sepsis following cholangitis. There were several common morphologic findings in the intrahepatic biliary tree of macroscopic and microscopic levels in infantile polycystic disease and congenital hepatic fibrosis with Caroli's disease: 1. irregular, non-obstructive dilatation of the duct lumen; 2. bulbar protrusion of the duct wall into the lumen; and 3. bridge formation of the duct wall across the lumen. These ductal changes might be caused by a combination of uneven and disproportionate overgrowth of biliary epithelia and their supporting connective tissue. This pathogenetic mechanism might be operative along the entire intrahepatic biliary system in this disease group, and involvement of the smaller levels in early life might result in infantile polycystic disease and congenital hepatic fibrosis and simultaneous or possibly later involvement of the larger levels in Caroli's disease.

Adult↗
PubMed1982

Inhibitory effects of alkylated Bence-Jones protein, k-type light chain, from urine of a patient with macroglobulinemia on gastric juice secretion and ulceration in rats.

Bence-Jones protein (BJP) was isolate from the urine of a patient with macroglobulinemia by salting out the ammonium sulfate, followed by chromatography on DEAE-cellulose column and gel filtration. This native BJP was identified as k-type light chain by immunoelectrophoresis and the native light chain showed almost no activity of inhibiting the gastric ulceration in pylorus-ligated rats. In contrast, reduction of the disulfide bond by 2-mercaptoethanol and alkylation of the thiol by iodoacetate in this native light chain resulted in significant inhibition of the gastric ulceration. The alkylated light chain also showed a significant inhibition of gastric juice secretion in pylorus-ligated rats.

Alkylation↗
PubMed1982

Increase of anti-ulcerogenic activity by reduction and alkylation of disulfide bonds of a globulin fraction from bovine serum.

Bovine serum was subjected to ammonium sulfate fractionation, and subsequently chromatographed on DEAE-cellulose column to obtain a globulin protein having a weak anti-ulcerogenic activity, Fr.II-A. Agar immunoelectrophoresis and immunodiffusion using rabbit antiserum against bovine IgG revealed that Fr.II-A from bovine serum shared antigenic determinant with bovine IgG. Furthermore, Fr.II-A showed a single band on polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. By reducing and alkylating the disulfide bonds by 2-mercaptoethanol and iodoacetic acid, Fr.II-A was separated into two subfragments in the same manner as in the case of immunoglobulin to produce Fr.L (molecular weight; 24000) and Fr.H (molecular weight; 50000). Fr.L showed anti-ulcerogenic activity up to about ten times greater than that of original Fr.II-A, but in the case of Fr.H, the activity increased approximately several times. Fr.L showed significant activity in preventing ulcer formation and gastric juice secretion in pylorus-ligated rats, and was also effective in reducing index of the phenylbutazone-induced ulcer.

Alkylation↗
PubMed1981

Purification and characterization of 6-aminohexanoic-acid-oligomer hydrolase of Flavobacterium sp. Ki72.

6-Aminohexanoic-oligomer hydrolase of Flavobacterium sp. KI72 was purified to homogeneity by column chromatography three times, and by preparation polyacrylamide gel electrophoresis twice. The purified enzyme had the following characteristics. 1. The molecular weight was estimated to be 84000 by Sephadex G-200 molecular-sieve chromatography. The enzyme consisted of two homologous subunits of 42000, judged from sodium dodecylsulfate/polyacrylamide gel electrophoresis. 2. The optimum pH for activity was between 8 and 9, the optimum temperature was 40 degrees C for a 1-h reaction. The Michaelis-Menten constants and turnover numbers for the 6-aminohexanoic acid dimer and trimer were 5.9 mM and 2.4 s-1, and 6.2 mM and 2.0 s-1 respectively. 3. The enzyme was inhibited by 0.37 mM diisopropylfluorophosphate and by 0.013 mM p-chloromercuribenzoate. 4. The enzyme was active on 6-aminohexanoic acid oligomers from dimer to hexamer and icosamer but not on hectamer, and the activity decreased with the increase of the polymerization number of the oligomer. The oligomers were hydrolyzed so as to remove the 6-aminohexanoic acid residue successively from the amino terminus. The enzyme could not hydrolyze other linear amides, cyclic amides, dipeptides, tripeptides or casein. 5. 6-aminohexanoic-acid-oligomer hydrolase was classified as a new member of the linear amidases (EC 3.5.1.-).

Amidohydrolases↗