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Biomedical subjects

F Kawai

Publications and source records attributed to F Kawai.

At least 55 records · Page 3Linked to original sources

Effects of moderate hypercapnia on hypothermia induced by cold He-O2 in rats.

1. Effects of moderate hypercapnia (10% CO2) on rectal temperature, oxygen consumption and body weight loss were examined during and after acute hypothermia induced by cold and helium-oxygen. 2. Hypothermia induction time was reduced significantly by hypercapnia. Rewarming tended to be faster in hypercapnic animals than in normocapnic animals. 3. Hypercapnia significantly reduced body weight loss when measured during hypothermia and during normothermia after rewarming. 4. Oxygen consumption during cooling was decreased by hypercapnia. 5. Exposure to 10% CO2 during cooling may spare energy substrate and favor survival in hypothermia.

Animals↗

Isolation and purification of a rat liver-specific antigen from hepatocyte membrane.

A rat liver-specific antigen (RLSA) solubilized with the nonionic detergent non-anonyl-N-methylglucamide was purified through affinity column chromatography with a monoclonal antibody and by high-performance liquid chromatography with a hydroxylapatite column. The purified RLSA showed a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and its molecular weight was determined to be 105,000 in the presence of 2-mercaptoethanol. The antigen was reactive to the Schiff reagent and contained glucosamine, but not galactosamine, indicating that the RLSA is a glycoprotein containing an asparagine-binding type of sugar chain.

Amino Acids↗

Biodegradation of polyethylene glycol by symbiotic mixed culture (obligate mutualism).

Neither Flavobacterium sp. nor Pseudomonas sp. grew on a polyethylene glycol (PEG) 6000 medium containing the culture filtrate of their mixed culture on PEG 6000. The two bacteria did not grow with a dialysis culture on a PEG 6000 medium. Flavobacterium sp. grew well on a dialysis culture containing a tetraethylene glycol medium supplemented with a small amount of PEG 6000 as an inducer, while poor growth of Pseudomonas sp. was observed. Three enzymes involved in the metabolism of PEG, PEG dehydrogenase, PEG-aldehyde dehydrogenase and PEG-carboxylate dehydrogenase (ether-cleaving) were present in the cells of Flavobacterium sp. The first two enzymes were not found in the cells of Pseudomonas sp. PEG 6000 was degraded neither by intact cells of Flavobacterium sp. nor by those of Pseudomonas sp., but it was degraded by their mixture. Glyoxylate, a metabolite liberated by the ether-cleaving enzyme, inhibited the growth of the mixed culture. The ether-cleaving enzyme was remarkably inhibited by glyoxylate. Glyoxylate was metabolized faster by Pseudomonas sp. than by Flavobacterium sp., and seemed to be a key material for the symbiosis.

Aldehyde Dehydrogenase↗

[Bacteriological and clinical studies of cefoxitin with special reference to anaerobic infections in the patients of abdominal surgery (author's transl)].

Both bacteriological and clinical studies of the effectiveness of cefoxitin (CFX) in the treatment of infections associated with abdominal surgery have been carried out at Tokyo Metropolitan Toshima Hospital from September 1979 through August 1980. The results of these studies are summarized in the following: 1. The clinical isolates from the 29 surgical patients were studied and anaerobes were found in 16 patients (55% of the patients). B. fragilis was found in 11 of the 16 patients (69%) from whom anaerobes were isolated. In all of these patients, aerobes were also isolated--most frequently E. coli or K. pneumoniae. 2. The in vitro antibacterial activity of cefoxitin (CFX) against 83 clinical isolates was compared to that of cephalothin (CET), cefazolin (CEZ) and carbenicillin (CBPC). The activity of CFX against Gram-positive bacteria was generally slightly inferior to that of the other 3 antibiotics. Among the Gram-negative aerobic organisms, CEZ was the most active against E. coli and CFX and CEZ against K. pneumoniae. However, CFX, with MIC's of 0.78-12.5 micrograms/ml, showed the greatest activity against B. fragilis, followed by CBPC, CEZ and CET, in order of decreasing activity. 3. CFX was administered in a 1-hour drip infusion to 3 patients following abdominal surgery, and concentrations of CFX in the serum and the exudate were measured. Peak serum concentrations were obtained at the end of the infusion, with a mean peak level of 97.93 micrograms/ml. Peak concentrations in the exudate were observed 30 to 60 minutes later and varied from 21.10 to 56.25 micrograms/ml. 4. Of the 20 patients administered of CFX, complete clinical and bacteriological data of anaerobic infections were available in 8 patients. The clinical evaluation was 'good' in 7 patients and 'fair' in 1. The bacteriological evaluation was 'eradicated' in 5 patients and 'decreased' in 3. As for side effects, elevations of S-GOT and S-GPT were observed in 4 of the 20 patients received CFX, but these abnormalities might also be attributable to other factors such as underlying disease, surgical intervention etc. No other side effects were found in these patients.

Abdomen↗

Purification and characterization of polyethylene glycol dehydrogenase involved in the bacterial metabolism of polyethylene glycol.

Polyethylene glycol (PEG) dehydrogenase in crude extracts of a PEG 20,000-utilizing mixed culture was purified 24 times by precipitation with ammonium sulfate, solubilization with laurylbetaine, and chromatography with diethylamino-ethyl-cellulose, hydroxylapatite, and Sephadex G-200. The purified enzyme was confirmed to be homogeneous by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular weight of the enzyme, which appeared to consist of four identical subunits, was 2.4 X 10(5). The enzyme was stable below 35 degrees C and in the pH range of 7.5 to 9.0. The optimum pH and temperature of the activity were around 8.0 and 60 degrees C, respectively. The enzyme did not require any metal ions for activity and oxidized various kinds of PEGs, among which PEG 6,000 was the most active substrate. The apparent Km values for tetraethylene glycol and PEG 6,000 were about 10.0 and 3.0 mM, respectively.

Alcohol Oxidoreductases↗

Bacterial oxidation of polyethylene glycol.

The metabolism of polyethylene glycol (PEG) was investigated with a synergistic, mixed culture of Flavobacterium and Pseudomonas species, which are individually unable to utilize PEGs. The PEG dehydrogenase linked with 2,6-dichlorophenolindophenol was found in the particulate fraction of sonic extracts and catalyzed the formation of a 2,4-dinitrophenylhydrazine-positive compound, possibly an an aldehyde. The enzyme has a wide substrate specificity towards PEGs: from diethylene glycol to PEG 20,000 Km values for tetraethylene glycol (TEG), PEG 400, and PEG 6,000 were 11, 1.7, and 15 mM, respectively. The metabolic products formed from TEG by intact cells were isolated and identified by combined gas chromatography-mass spectrometry as triethylene glycol and TEG-monocarboxylic acid plus small amounts of TEG-dicarboxylic acid, diethylene glycol, and ethylene glycol. From these enzymatic and analytical data, the following metabolic pathway was proposed for PEG: HO(CH2CH2O)nCH2CH2OH leads to HO(CH2CH2O)nCH2CHO leads to HO(CH2CH2O)nCH2COOH leads to HO(CH2CH2O)n-1CH2CH2OH.

Chemical Phenomena↗

Identification and properties of reactive sites in protein capable of binding carbon dioxide in a gas-solid phase system.

In order to identify the functional groups which really contribute to the carbon dioxide gas adsorption by proteins, epsilon-amino groups of lysine residues of egg albumin were chemically modified with trinitrobenzene sulfonic acid to various degrees. About 60% of the total amount of carbon dioxide gas absorbed by solid egg albumin diminished by complete modification. The amount of carbon dioxide gas adsorbed by lysozyme, its hydrolyzates and gelatin hydrolyzates depended upon the lysine content, arginine content and average molecular weight. The good correlation was obtained between the amount of carbon dioxide gas absorbed and the total of lysine and arginine content of them. The ability of carbon dioxide gas adsorption by alpha-amino group of amino acids and oligopeptides was found to be developed by the elongation of the peptide chain of glycine and other amino acid, by the removal of alpha-carboxyl group of histidine and tyrosine to corresponding amines and by the esterification of alpha-carboxyl group of leucine with p-nitrophenol. These results clearly indicate that CO2 binding sites in protein in the gas-solid phase system are epsilon-amino, alpha-amino and guanidinium groups.

Amino Acids↗

Carbon dioxide-protein interaction in a gas-solid phase.

In the course of developing the packaging of protein foods under the carbon dioxide atmosphere, various proteins in a solid state were found to adsorb carbon dioxide gas gradually. The results obtained by the Warburg manometry indicated that 100-1000 mul of carbon dioxide gas was adsorbed at 25 degrees C for 24 hr by gram of purified proteins, dried protein foods and other proteinous materials such as the rabbit hair and raw silk when they were placed in the high partial pressure of carbon dioxide gas. Casein, gelatin and raw silk were revealed to be the better adsorbents comparing with egg albumin, hemoglobin, gluten and others tested in this experiment. This adsorption was found to be almost specific to carbon dioxide gas. Amount of carbon dioxide gas adsorbed by casein and gelatin depended on the moisture content of them. The lower the moisture is, the greater the adsorption amount of carbon dioxide gas increase. Peptones and partial hydrolyzates of gelatin also showed the adsorbability. Oligo-peptides, amino acids and amines were examined too. Among these, L-lysine (free base), L-arginine (free base), histamine and tyramine adsorbed a large amount of carbon dioxide gas while others failed to do so. Some differences, however, were observed between temperature dependence and reversibility of the carbon dioxide gas adsorption by proteins and those by amines and amino acids (free bases). The mode of interaction between carbon dioxide and protein in a gas-solid phase was discussed comparing with the results obtained in a gas-liquid phase. Large contribution of physical adsorption and less contribution of chemical reaction or chemisorption were assumed in the mode of the carbon dioxide-protein interaction.

Adsorption↗