A simple direct spectrophotometric method for the determination of butyrylcholinesterase (EC 3.1.1.8) and arylesterase (EC 3.1.1.2) activities has been developed. New chromogenic substrates, (3-carboxypropyl) trimethylammonium iodide o-nitrophenyl ester (I) and (3-carboxypropyl) trimethylammonium iodide p-nitrophenyl ester (II), as well as new fluorogenic substrate, (3-carboxypropyl) trimethylammonium iodide 4'-methylumbelliferyl ester (III), were used in this study. Horse serum butyrylcholinesterase equally catalyzed hydrolysis of the compounds, I, II and III. Hydrolysis of these compounds by trypsin, chymotrypsin, acetylcholinesterase and carboxylesterase was negligible or quite slow. By human serum butytylcholinesterase, however, only the compound I was preferentially hydrolyzed. The compound III, by contrast, was found to be a specific substrate for arylesterase of human serum without being affected by the butyrylcholinesterase. All these measurements were carried out readily and efficiently, by analyzing highly colored products with I and II, and highly fluorescent product with III.

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In the process of immunization of rabbits with cyclic AMP or cyclic GMP, the plasma concentration of cyclic AMP or cyclic GMP was markedly elevated as the titer of the antiserum increased. The i.v. injection of anti-cyclic AMP or anti-cyclic GMP antiserum into rats or mice also caused a marked increase in the respective cyclic nucleotide in plasma. On the other hand, an injection with the antiserum did not cause any significant increase in urinary cyclic nucleotides. Therefore, the effect of the antiserum seems to be different from that of glucagon or carbamylcholine which increases cyclic AMP or cyclic GMP respectively in both plasma and urine. The injection of the antiserum, but not nephrectomy, caused a significant increase in plasma cyclic nucleotides in adrenalectomized rats. This made it unlikely that the antiserum-induced increase was due to the inhibition of urinary excretion. The plasma cyclic nucleotides, increased by an i.v. injection with the antiserum, servived enzymatic hydrolysis by phosphodiesterase in vitro ; most of them proved to be bound to the antibody. It was concluded that the increases in plasma cyclic nucleotides in the process of cyclic nucleotide-immunization were mainly due to decreased metabolic clearance of plasma cyclic nucleotides.

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The enzymic cis-trans isomerization of nitrothiophene and nitrobenzene derivatives was comparatively investigated by using the geometrical isomers of 3-(5-nitro-2-thienyl)-2-(2-furyl) acrylamide and 3-(4-nitrophenyl)-2-(2-furyl)-acrylamide. As a result, the nitrothiophene derivative was mainly isomerized from the cis to the trans form by milk xanthine oxidase or rat liver microsomes supplemented with an electron donor. In the case of the nitrobenzene derivative, however, such enzymic cis-trans isomerization was not observed in these enzyme systems.

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In an attempt to clarify mechanisms of anti-inflammatory actions of steroidal and nonsteroidal anti-inflammatory drugs with special reference to the possible role of E type prostaglandins in the inflammatory process, mode of actions of these drugs was investigated by using acute exudative stage and chronic proliferative stage of carrageenin-air-pouch inflammation in rats. This inflammation was induced on the back of rats by subcutaneous injection with air and carrageenin solution. Plasma exudation in the inflammation locus was determined with the aid of radioiodinated serum albumin. In the acute exudative stage of this inflammation, a single oral administration of dexamethasone, indomethacin, phenylbutazone or aspirin all exerted potent anti-exudative effect, while in the chroic proliferative stage, only dexamethasone was effective in inhibiting the exudation of the labeled albumin. Prostaglandin E level in the exudate of the acute stage inflammation was suppressed by either dexamethasone or indomethacin in accordance with the inhibition of the vascular permeability. These results suggest (1) significant role of prostaglandin E in the acute exudative inflammation, (2) similarity between steroidal and nonsteroidal anti-inflammatory drugs in the mechanism of their anti-exudative actions in the acute inflammation, (3) independency of the exudative process in the chronic proliferative inflammation from prostaglandins and (4) role of extra-prostaglandin mechanism(s) for the anti-exudative action of the anti-inflammatory steroids.

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The biological fates of ethyl paraben and p-hydroxybenzoic acid in rat were investigated after intravenous and intraduodenal administrations at the dose of 2 mg/kg. The blood concentrations were measured in detail from 3 min after the administration at appropriate time intervals until 90 min. Areas under the blood concentration curves and clearances were calculated from these time course data. Ethyl paraben was little detected in blood after intraduodenal administration. It is suggested that the intestinal metabolism and the first pass effect in liver greatly contribute to the hydrolysis of ethyl paraben. Total radio activity after intraduodenal administration did not show the maximum peak and decreased rapidly. The maximum peak was not observed also in the time course of p-hydroxyhippuric acid after intravenous administration. It shows that not only the rate of hydrolysis but also absorption and conjugation are very rapid. The differences of the areas under the blood concentration curves of p-hydroxybenzoic acid or p-hydroxyhippuric acid was found between the routes or chemical forms of administration. The complex kinetic mechanisms were assumed in the biological fates of these compounds as follows : Conjugation to p-hydroxyhippuric acid is excellent in ethyl paraben administration than p-hydroxybenzoic acid, and in intraduodenal administration than intravenous administration. These phenomenon can not be explained by the conventional kinetic model which is constructed with the connected blood compartments in series. The kinetic models including the assumed routes conjugating directly ethyl paraben in blood or intestine to p-hydroxyhippuric acid were presented, and the least square curve fitting analyses were carried out on these kinetic models.

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The susceptibility of 416 clinical isolates of Escherichia coli to ampicillin, cephaloridine and cefoxitin was determined, and 39 isolates were found to be resistance to 25 μg/ml or higher concentrations of cephaloridine. Five of the cephaloridine-resistant strains further exhibited resistance to cefoxitin which is a novel cephamycin antibiotic stable to many types of β-lactamases. The cephaloridine-resistant strains except the strains resistant to cefoxitin produced a large amount of type I penicillinase mediated by R plasmid, while all the cefoxitin-resistant strains produced a cephalosporinase (2 strains) or both of the cephalosporinase and the type I penicillinase (3 strains). Although the cephalosporinase failed to hydrolyze cefoxitin effectively in vitro, the close relationship between the cephalosporinase production and the cephaloridine and cefoxitin resistances in the E. coli strains was suggested. The conjugal transfer of the cefoxitin resistance to an E. coli strain was unsuccessful.

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