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Biomedical subjects

J Goto

Publications and source records attributed to J Goto.

At least 217 records · Page 12Linked to original sources
PubMed1984

Studies of 7 beta-[2-(aminoaryl)acetamido]-cephalosporin derivatives. I. Synthesis and structure-activity relationships in the aminopyridine series.

The synthesis and in vitro activity of 7 beta-(2-aminopyridyl-2-alkoxyiminoacetamido)cephalosporins with various substituents at the 3-position are described. The effects of substitution pattern on the pyridine ring, oxime substituent and 3-substituent were studied as a function of the MIC values. Of these various kinds of derivatives, 7 beta-[2-(2-aminopyridin-6-yl)-2-alkoxyiminoacetamido]cephalo sporins exhibited significantly higher activity against most of micro-organisms.

Aminopyridines↗
PubMed1984

Studies of 7 beta-[2-(aminoaryl)acetamido]-cephalosporin derivatives. II. Synthesis and structure-activity relationships in the aminopyrimidine series.

The synthesis and the antibacterial activity of 7 beta-[2-(aminopyrimidinyl)-2-oxyiminoacetamido]cephalosporin s with various substituents at the 3-position in the cephem nucleus are described. The 7 beta-[2-(4-aminopyrimidin-2-yl)-2 -methoxyiminoacetamido]cephalosporin derivative (1) showed significantly higher activity than the corresponding 2-aminopyrimidin-4-yl derivative (2) against Gram-negative bacteria. It was also higher in potency against Escherichia coli and Serratia marcescens than the aminopyridyl compound (4).

Bacteria↗
PubMed1984

Studies of 7 beta-[2-(aminoaryl)acetamido]-cephalosporin derivatives. III. Synthesis and structure-activity relationships in the aminothiadiazole series.

The synthesis and in vitro antibacterial activity of 7 beta-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-oxyiminoacetamido] cephalosporins with various substituents at the 3-position in the cephem nucleus are described. Aminothiadiazolyl cephalosporins having pyridiniomethyl groups at the 3-position exhibited excellent activity against all organisms, particularly against Pseudomonas aeruginosa.

Bacteria↗
PubMed1984

[The inhibitory effect of oxaprozin, a new non-steroidal anti-inflammatory drug, on platelet aggregation].

The inhibitory effects of oxaprozin, a new non-steroidal anti-inflammatory drug, on platelet aggregation and prostaglandin (PG) synthetase activity were studied. In arachidonic acid (AA)-induced rabbit platelet aggregation in vitro, oxaprozin exhibited a dose-dependent inhibitory effect, and its median inhibitory concentration was 124.2 microM. The effect of oxaprozin was less potent than that of indomethacin and piroxicam, equipotent as that of aspirin and phenylbutazone, and 2 times as potent as that of ibuprofen. In collagen-induced rat platelet aggregation ex vivo, oxaprozin showed a weak but significant inhibitory effect with oral dose of 300 mg/kg. Indomethacin, aspirin and ibuprofen exhibited an inhibitory effect with 100 mg/kg. Although phenylbutazone also exhibited an inhibitory effect with 300 mg/kg, the effect was more potent than that of oxaprozin. ADP-induced platelet aggregation both in rabbit in vitro and rat ex vivo was not affected by oxaprozin. Moreover, oxaprozin administered orally inhibited dose-dependently AA-induced pulmonary thrombotic mortality in mice, and its median effective dose was 56.4 mg/kg. The effect of oxaprozin was less potent than of sulindac, piroxicam and ibuprofen, equipotent as that of aspirin, and 5 times as potent as that of phenylbutazone. On the other hand, oxaprozin inhibited dose-dependently PG synthetase activity. The inhibitory effect of oxaprozin was less potent than that of indomethacin and piroxicam, almost equipotent as that of ibuprofen, and more potent than that of phenylbutazone and aspirin. These results suggest that oxaprozin, like many other acidic non-steroidal anti-inflammatory drugs, suppresses platelet aggregation by mainly inhibiting PG synthetase activity.

Adenosine Diphosphate↗
PubMed1983

Studies on steroids. CLXXXVII. Determination of serum bile acids by high-performance liquid chromatography with fluorescence labeling.

A method for the simultaneous determination of bile acids in serum by high-performance liquid chromatography (HPLC) with fluorescence labeling is described. The bile acid fraction was obtained from a serum specimen by passing it through a BondElut cartridge. Bile acids were derivatized quantitatively into the fluorescent compounds through the hydroxyl group at C-3 by treatment with 1-anthroyl nitrile in the presence of quinuclidine in acetonitrile. These derivatives were separated into the free, glycine- and taurine-conjugate fractions by ion-exchange chromatography on a lipophilic gel, piperidinohydroxypropyl Sephadex LH-20. Subsequent resolution of each fraction into cholate, ursodeoxycholate, chenodeoxycholate, deoxycholate and lithocholate was attained by HPLC on a Cosmosil 5C18 column using 0.3% potassium phosphate buffer (pH 6.0)--methanol (1:5) and 0.1% potassium phosphate buffer (pH 6.0)--methanol (1:8) as mobile phases. The anthroyl bile acids were monitored by fluorescence detection (excitation wavelength 370 nm; emission wavelength 470 nm), the limit of detection being 20 fmol. The proposed method proved to be applicable to the quantitation of bile acids in serum with satisfactory reliability and sensitivity.

Bile Acids and Salts↗
PubMed1983

Impaired metabolism of arachidonate in selenium deficient animals.

Arachidonate-induced respiratory distress in mice was aggravated in a selenium deficient group as compared with a selenium supplemented one. The aggravation in selenium deficient mice may be due to enhanced platelet aggregation and suppressed formation of prostacyclin (PGI2) in the arterial all.

Adenosine Diphosphate↗
PubMed1983

The simultaneous determination of serum cortisol and cortisone by high-performance liquid chromatography with fluorimetric detection.

A new method for the simultaneous determination of cortisol and cortisone in serum by high-performance liquid chromatography with fluorimetric detection has been developed. The two steroids were derivatized by treatment with 9-anthroyl nitrile in triethylamine-acetonitrile to give the fluorescent esters through the 21-hydroxyl group. These derivatives were efficiently separated on a straight-phase Cosmosil 5SL column with hexane-ethyl acetate (6:5) as eluent. The detection limit was 20 fmol, using the 9-anthroyl derivative of prednisolone as an internal standard. The use of Sep-Pak C18 and Clin-Elut cartridges proved to be efficient for the clean-up of cortisol and cortisone in serum samples.

Journal Article↗
PubMed1983

Effects of timing of vagal stimulation on the sinoatrial nodal cell discharge.

The effects of vagal stimulation on the activity of the isolated rabbit sino-atrial (SA) node preparation were studied using electrophysiological techniques. Brief stimulus trains, which were subthreshold for the myocardial cells, were applied in order to release acetylcholine (ACh) from the nerve terminals. Transmembrane potentials were recorded from the follower cells located at the exit site near the pacemaker region. As the time from peak of the action potential to delivery of the vagal stimuli was progressively increased, the sinus cycle length first became progressively prolonged, and then was rapidly reduced to the control value. In order to resolve the underlying mechanisms for the phase-dependency, the effects of vagal stimulation were examined in a quiescent SA node preparation. When one stimulus was applied, membrane hyperpolarization began after a latency of 70 msec and developed slowly, reaching its peak value after about 270 msec, and its total time course was about 630 msec. Oscillatory potentials were observed after the recovery of the vagal-induced hyperpolarization; such oscillations were not observed in atrial myocardial cells. It is concluded that the slow-onset long-lasting response of the SA node cell membrane to ACh may play a role in the phase-dependent effect of vagal stimulation.

Acetylcholine↗