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S Baba

Publications and source records attributed to S Baba.

At least 829 records · Page 46Linked to original sources

Plasma levels and urinary excretion of batroxobin and its defibrinogenating effects in various animal species.

The plasma levels and urinary excretion of batroxobin administered to 6 species of animals were examined by an enzyme immunoassay method. Defibrinogenating effect of batroxobin was also studied in those species. The plasma levels of immunoreactive batroxobin disappeared exponentially in all the animals and differences in half-life were observed to occur according to species. The elimination half-life of immunoreactive batroxobin in the plasma was the largest in dogs, followed by rats, monkeys, guinea pigs, mice and rabbits. The extent of the defibrinogenating effect was also noted to vary according to the species, being greatest in dogs and then monkeys, mice, rats, guinea pigs and rabbits. Following the continuous infusion of batroxobin into dogs, its level in the plasma remained high over a considerable period of time and the defibrinogenating effect lasted in corresponding to its plasma level. The urinary excretion of immunoreactive batroxobin was quite small in these species, being 0.2-1.9% of the original dose.

Animals↗

Metabolic fate of 125I-labeled batroxobin in rats and dogs.

125I-Labeled batroxobin was prepared and following its intravenous and subcutaneous administrations to rats and dogs, the blood radioactivity was determined. In the both species following the intravenous injections, the decrease in radioactivity was biexponential. Following subcutaneous administration, radioactivity became maximal at 6h and decreased in a manner similar to that of the beta-phase of the intravenous injection. The blood concentration of fibrinogen in dogs was also determined. After the intravenous injection, fibrinogen became undetectable 1h later, and appeared again in the blood at 24h. After the subcutaneous injection, the decrease was not so rapid. Fibrinogen resumed its original levels at 7 day after the administration in both the routes. Radioactivity after the both injections was excreted generally in the urine in about the same amounts. The total urinary and fecal excretions in rats and dogs were 80 and 95%, respectively. The distribution of radioactivity in the tissues was examined by counting technique and whole-body autoradiography. Radioactivity predominantly accumulated in the thyroid and stomach and could also be found in the kidneys and liver in fair amounts. The distribution patterns of radioactivity for both the routes of administrations and also for male and pregnant rats were basically the same. In fetus rats, a slight distribution was noted. From the results of gel filtration chromatography and trichloroacetic acid fractionation, [125I] batroxobin was metabolized soon after the administration to afford low molecular substances such as 125I-ion in the plasma and urine.

Animals↗

Immunochemical characterization of anti-islet cell surface monoclonal antibody from nonobese diabetic mice.

We have produced a monoclonal antibody 3A4 to the surface of islet cells by fusing spleen lymphocytes from nonobese diabetic (NOD) mice. To identify the molecular weight of specific target antigens reacting with 3A4, 125I-surface-labeled In-111 insulinoma cells were solubilized and extracts were absorbed with 3A4, and immunoprecipitates were followed by polyacrylamide gel electrophoresis and autoradiography. 3A4 recognized two major polypeptides with apparent molecular weights of radioactive 64K and inactive 28K. In order to evaluate the antibody-mediated cytotoxic mechanisms of 3A4, complement-dependent antibody-mediated cytotoxicity (C'-AMC) and antibody-dependent cellular cytotoxicity (ADCC) were tested using a method of specific 51Cr release. In the study for C'-AMC, even over wide ranges of concentration of antibody and rabbit complement, purified 3A4 had no apparent cytotoxic effects on In-111 cells. On the other hand, significant ADCC was observed at an antibody concentration of 10 micrograms/ml and a target:effector cell ratio of 1:40 (P less than 0.01). Finally, the effects of 3A4 on glucose-stimulated insulin release were examined in isolated rat islets. At a glucose concentration of 16.7 mM, 3A4 significantly inhibited the insulin release either in the presence or absence of complement (P less than 0.01). In conclusion, 3A4 could not only bind but also be active to the target cells. Therefore, this monoclonal antibody should be a useful tool to permit a detailed analysis of the pathogenesis of type I diabetes mellitus.

Animals↗

Purification and characterization of insulin-degrading enzyme from human erythrocytes.

An insulin-degrading enzyme (IDE) was purified from the cytosol of human erythrocytes via the use of ammonium sulfate precipitation and chromatography on columns composed of DEAE-Sephadex, pentylagarose, hydroxylapatite, chromatofocusing resins, and Ultrogel AcA-34. The final preparation was purified greater than 50,000-fold and exhibited a single protein band of Mr = 110,000 on reduced sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Cross-linking of 125I-labeled insulin to the enzyme preparation labeled a protein of the same molecular weight, indicating that this band was in fact the enzyme. Intact insulin, insulin B chain, and glucagon inhibited this cross-linking half-maximally at concentrations of 0.1, 1, and 1.5 microM, respectively. Under nondenaturing conditions, the enzyme had an Mr = 300,000, suggesting that the enzyme may exist under physiological conditions as a dimer or timer. The purified enzyme was inhibited by both sulfhydrylmodifying reagents and chelating agents, indicating that a free thiol and metal were both required for the activity of the enzyme. The purified enzyme was found to degrade physiological concentrations of intact insulin more rapidly than insulin B chain, although at high substrate concentrations (greater than 1 microM) the enzyme degraded B chain to a greater extent. Additional characteristics of the enzyme were a pl of 5.2 and a pH optimum of 7.0. These properties of the red blood cell (RBC) enzyme were very similar to those reported for IDEs from other tissues. Moreover, a polyclonal antiserum to the IDE from skeletal muscle was found to recognize the RBC enzyme.

Chemical Precipitation↗

Hb Himeji or beta 140 (H18) Ala----Asp. A slightly unstable hemoglobin with increased beta N-terminal glycation.

A fast-moving abnormal hemoglobin found in a diabetic patient was identified as beta 140 (H18) Ala----Asp. It comprised about 40% of the total hemoglobin. The beta N-terminal glycation in the abnormal hemoglobin was estimated to be 3 times as much as that in Hb A in the same blood sample. The abnormal hemoglobin was slightly unstable. Oxygen affinity of the stripped hemoglobin was decreased, but that of red cells from the carrier was slightly higher than normal because of the reduced effect of 2,3-diphosphoglycerate.

Blood Protein Electrophoresis↗

[Efficacy evaluation of aztreonam for suppurative otitis media].

Preclinical and clinical studies were performed to evaluate usefulness and safety of aztreonam (AZT) in the treatment of acute otitis media, acute exacerbation of chronic otitis media and chronic otitis media and the following results were obtained. MICs for P. aeruginosa, P. mirabilis and P. inconstans isolated from the patients with suppurative otitis media were 1.56 micrograms/ml, less than or equal to 0.025 micrograms/ml and less than or equal to 0.025 micrograms/ml respectively in their peaks. In the intravenous injection of 1 g, AZT concentration in the mastoid cell mucosa was 7.52 micrograms/g on average and serum concentration 51.6 micrograms/ml sufficiently suggesting clinical efficacy of AZT. In the clinical trial by administering AZT 1-2 g/day for the patients with suppurative otitis media, effective rates were 2/3 (66.7%) for acute otitis media, 16/22 (72.7%) for acute exacerbation of chronic otitis media, 21/34 (61.8%) for chronic otitis media and 6/7 (85.7%) for cholesteatoma of the middle ear. Elimination rate of single Gram-negative pathogens was 82.1% in the bacteriological studies of AZT. As for abnormal laboratory findings, 7 cases showed GOT, GPT elevations. However, they were in minor degree and transient. Side effect was not noted except 1 case of flushing with itching. It was considered from the above results that AZT is a highly useful antibiotic for suppurative otitis media.

Adult↗