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Biomedical subjects

S Baba

Publications and source records attributed to S Baba.

At least 1,045 records · Page 58Linked to original sources
PubMed1981

Effects of porcine secretin on exocrine and endocrine function in the isolated perfused rat pancreas.

The effects of both synthetic and pure natural porcine secretin on immunoreactive insulin (IRI) and immunoreactive glucagon (IRG) release and on pancreatic exocrine secretion were studied in the isolated perfused rat pancreas. Synthetic porcine secretin stimulated a significant increase in pancreatic juice flow and amylase output at concentrations as low as 0.01 and 0.1 ng/ml, respectively. The maximal peak rate of both juice flow and amylase output was observed at 1 microgram/ml synthetic secretin. Synthetic secretin at concentrations up to 2 micrograms/ml and pure natural porcine secretin at a concentration of 1 clinical unit/ml had no effect on IRI secretion regardless of the glucose concentration (50, 100, or 150 mg/100 ml) in the perfusate. Both types of secretin, however, elicited a concentration-dependent increase in IRG secretion in the presence of 50 mg/100 ml glucose. The lowest synthetic secretin concentration causing a significant increase in IRG release was 0.1 ng/ml, and maximal stimulation was observed at 1 microgram/ml. These concentrations were similar to those eliciting minimal and maximal amylase release. Thus, synthetic and pure natural porcine secretin have been shown to not only stimulate pancreatic juice flow and amylase secretion but also to elicit IRG release from the isolated perfused rat pancreas.

Amylases↗
PubMed1981

Purification and characterization of insulin-degrading enzyme from pig skeletal muscle.

An enzyme capable of degrading insulin was purified from pig skeletal muscle and studied for its characteristics. Purification of the enzyme was successfully achieved by a combination of ammonium sulfate precipitation, chromatography of Bio-Gel P-200 and DEAE-cellulose, and, finally, ampholine isoelectrofocusing. The enzyme obtained showed 741-fold purification in its activity and a single band on polyacrylamide gel electrophoresis. The purified enzyme degraded insulin proteolytically and was sulfhydryl dependent. The Km for insulin was 70 nM. Proinsulin behaved as a competitive inhibitor for insulin degradation; its Ki was 320 nM. Glucagon was also proteolytically degraded, whereas number of other peptides, including A and B chains of insulin, were not appreciably affected by this enzyme. The molecular weight of the enzyme was estimated to be 135,000 by gel filtration on Sephadex G-200 and 60,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This enzyme and lysosomal enzymes extracted from rat liver were shown to be different, judging from their optimal pH for insulin degradation and substrate specificity. These studies demonstrate the presence of an insulin-degrading enzyme in pig skeletal muscle and suggest that this enzyme is identical to rat insulin protease in most of its biochemical properties.

Animals↗
PubMed1981

Insulin release from the isolated perfused rat pancreas containing insulinomata induced by streptozotocin and nicotinamide: effects of glucose and responses to tumor removal.

The kinetics of insulin secretion in response to glucose were studied in the in vitro perfused rat pancreas before and after removal of islet cell tumors induced by streptozotocin and nicotinamide. In addition, insulin secretion before and after tumor removal was compared with that from normal pancreata before and after sham operations, respectively. Thus, the two pancreas preparations were subjected to repeated perfusions with glucose. Perfusion of pancreata containing tumors with 8.4 mM glucose resulted in biphasic release in a pattern similar to that of normal pancreas. However, both basal and stimulated insulin secretion of tumor-bearing pancreata were greater than either those of pancreata from which tumors had been excluded by ligature or those of normal pancreata before sham operation. A second increase in the concentration of glucose from 2.8 to 8.4 mM also produced a biphasic release of insulin from extratumoral pancreata as well as from sham-operated normal pancreata. However, the insulin secretory response to glucose of extratumoral pancreatic tissue was less than that of control pancreatic tissue. Our findings indicate that pancreatic islet cell tumors induced by streptozotocin and nicotinamide respond to glucose with typical biphasic insulin release. Thus, chemically induced rat insulinomata may provide a readily available and valuable model of insulin-secreting tissue, analogous to normal islets. Furthermore, our study suggests that the B cell function of pancreata containing tumors is inhibited by the preexisting tumor-induced hyperinsulinism or by its metabolic consequences.

Adenoma, Islet Cell↗
PubMed1981

Synthesis of selectively 3H or 14C-labeled 2-(4-(2-thienylcarbonyl)phenyl)propionic acid.

2-(4-(2-Thienylcarbonyl)phenyl)propionic acid (suprofen), an anti-inflammatory agent, was labeled with tritium or carbon-14 for the purpose of investigating its metabolic fate in animals. The selectively tritiated suprofen (26.3-32.1 GBq (710-867 mCi)/mmol) was obtained by catalytic dehalogenation of the brominated precursor with 185-370 GBq (5-10 Ci) of tritium gas. The labeled position of the suprofen was confirmed by spectral data of the deuterated suprofen similarly synthesized. On the other hand, suprofen-14C (48.8 MBq (1.4 mCi)/mmol) was obtained by five-step synthesis from toluene [methyl-14C] in a 19% yield.

Anti-Inflammatory Agents↗
PubMed1981

Synthesis of optically active 2-(4-(2-thienylcarbonyl)-phenyl)propionic acid labeled with deuterium.

2-(4-(2-Thienylcarbonyl)phenyl)propionic acid (suprofen), an anti-inflammatory agent, was labeled with multiple-deuterium for the purpose of investigating the metabolism in man and animals by the ion cluster technique. Racemic suprofen-d4 was prepared by ten-stop synthesis from bromobenzene-d5 in a 32% yield, and its deuterium content was 99 atom%. This racemic suprofen-d4 was resolved by use of an optically active alpha-methylbenzylamine, resulting that optically active suprofen-d4 was obtained in a 11% yield and was 96.5 atom% D. On the other hand, suprofen-d7 (99 atom% D) was obtained by five-step synthesis from toulene-d8 and methyl-d3 iodide in a 24% yield.

Anti-Inflammatory Agents↗
PubMed1981

[Laboratory and clinical studies on ceftizoxime in otorhinolaryngological field (author's transl)].

From the laboratory and clinical studies on ceftizoxime (CZX), the following results were obtained 1) CZX was compared with cefazolin (CEZ) for in vitro activity against 6 standard strains and clinically isolated strains of Staphylococcus aureus (19 strains), Staphylococcus epidermidis (14), Proteus sp. (17), Escherichia coli (3), Klebsiella sp. (3) and Pseudomonas aeruginosa (13). While somewhat less active against Gram-positive cocci than CEZ, CZX was far more active than CEZ against Gram-negative bacilli. 2) The time course of mean serum CZX levels in 2 patients given a single intravenous dose of 10 mg/kg was as follows: 24.9 microgram/ml at 15 minutes, 18.5 microgram/ml at 30 minutes, 13.2 microgram/ml at 1 hour, 6.4 microgram/ml at 2 hours and 2.7 microgram/ml at 4 hours. The mean serum half life was 1.36 hours. The mean tonsil concentrations of CZX 30 minutes after a single intravenous dose of 0.5 g and 1.0 g were 5.9 microgram/g and 9.6 microgram/g. respectively, with the ratio to the serum concentration of 0.33 and 0.32. 3) CZX was given to 28 patients with ear, nose, and throat infections, and overall rate of effectiveness was 92.3%. No clinical side effects were observed. Changes in laboratory test findings included slightly elevated GOT and/or GPT in 3 cases.

Adolescent↗