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Biomedical subjects

K Hirose

Publications and source records attributed to K Hirose.

At least 451 records · Page 25Linked to original sources
PubMed1981

Effects of proteases on the structure and activity of Pseudomonas aeruginosa exotoxin A.

The effects of various proteases on the enzymatic or biological activity and structure of exotoxin A from Pseudomonas aeruginosa were systematically studied. The toxin was extremely resistant to treatment with various enzymes. The lethality of the toxin disappeared upon treatment with P. aeruginosa protease and elastase, thermolysin, and trypsin with a long incubation time (5h) in the presence of a high enzyme concentration (molar concentration of enzyme to toxin, 1:10 or 1:20), but was little altered by either alpha-chymotrypsin or subtilisin. The decrease of adenosine diphosphate ribosylation activity was moderate when the same treatment was used, regardless to the protease source, except in the case of papain, which was tested in the presence of reducing agents. The increase in activation of the treated toxin determined in the presence of a denaturant and a reducing agent was less than that of the intact toxin, except in the case of trypsin. The differences in disc and sodium dodecyl sulfate gel electropherograms of the toxins treated with these proteases, except for those treated with papain, suggested that the toxins had been nicked by the protease, which resulted in their degradation by sodium dodecyl sulfate treatment. Papain degraded the toxin into fragments and caused the disappearance of lethality or a marked decrease of adenosine diphosphate ribosylation activity.

ADP Ribose Transferases↗
PubMed1981

Pharmacology of 2-o-chlororbenzoyl-4-chloro-N-methyl-N alpha-glycylglycinanilide hydrate (45-0088-S), a compound with benzodiazepine-like properties.

2-o-Chlorobenzoyl-4-chloro-N-methyl-N alpha-glycylglycinanilide hydrate (45-0088-S), a dipeptido-aminobenzophenone compound, inhibited pentetrazole-induced convulsion and suppressed electroshock-induced fighting behavior in mice, reduced conflict behavior in rats and monkeys, and induced muscle relaxation in cats at lower doses than did diazepam. This pharmacological profile suggests that 45-0088-S can be an active, water-soluble antianxiety agent in man.

Aggression↗
PubMed1981

[Effects of verapamil on systolic time intervals and relaxation time in hypertrophic cardiomyopathy (author's transl)].

In order to determine the effect of verapamil, a calcium-channel blocking agent, on systolic performance and relaxation in hypertrophic cardiomyopathy (HCM), 12 patients with HCM and 10 normal subjects were studied. Echocardiograms, phonocardiograms, carotid pulses, and apex cardiograms were recorded simultaneously at the control state and 5, 10, and 15 min after intravenous injection of 10 mg of verapamil. After verapamil administration, heart rate was unchanged, while systolic blood pressure was slightly reduced in both groups. In normal subjects no significant changes were observed in systolic time intervals, such as ET, delta ET, PEP, delta PEP and PEP/ET, and mean VCF, except slightly prolonged delta ET after 5 min of the injection. The duration of isovolumic relaxation, (IIa-D) interval, taken as the period from the aortic valve closure (IIa) to the onset of mitral valve cusp separation and the time from IIa to the O point of the apex cardiogram, (IIa-O) interval, were 58 +/- 5 and 123 +/- 16 msec, respectively. The maximum velocity of the left ventricular posterior wall in early diastole (PWDV) was 128 +/- 10 mm/sec. These intervals and the velocity were not significantly changed after verapamil administration. In patients with HCM, ET and delta ET were unchanged, but PEP and delta PEP prolonged at 10 and 15 min after verapamil administration. PEP/ET was increased and mean VCF was reduced at 15 min after injection. In comparison with normal subjects, IIa-D interval and Ha-O interval were prolonged definitely at control, 92 +/- 21 and 190 +/- 28 msec, respectively. PWDV was slower than normal, 86 +/- 18 mm/sec at control. After verapamil, these intervals were shortened and PWDV fastened significantly. These results indicated that verapamil is regarded to have slight intrinsic negative inotropic action, suggesting the beneficial effect to reduce intraventricular pressure gradient, and also improve impaired myocardial relaxation in HCM.

Adult↗
PubMed1980

Peptidoaminobenzophenones, a novel class of ring-opened derivatives of 1,4-benzoidazepines.

A series of noval peptidoaminobenzophenones has been prepared via several routes and was evaluated for CNS activity. The structure--activity relationships in the series are discussed. In general, dipeptido-N-methylaminobenzophenones showed higher activities than the corresponding NH derivatives. Some compounds had very high activities in antipentylenetetrazole and antifighting tests in mice when orally administered. Very weak toxicity was also found in these compounds. Water solubility of the peptidoaminobenzophenones and their salts were tested. Possible in these compounds. Water solubility of the peptidoaminobenzophenones and their salts were tested. Possible in vivo conversion of peptidoaminobenzophenone by enzymatic cleavage of the terminal amino acid, followed by chemical cyclization to 1,4-benzodiazepine, is also discussed. Such novel open-ring derivatives of 1,4-benzodiazepine may serve as useful CNS agents.

Aggression↗
PubMed1980

Distribution of citrate utilization plasmids in Salmonella strains of bovine origin in Japan.

Attempts to detect transferable citrate-utilizing (Cit) ability in enterobacterial strains were carried out by conjugation experiments. Of 318 strains of Salmonella typhimurium and 1 strain of Salmonella bredeney isolated from cattle in Japan from 1970 to 1979, 107 (33.5%) strains contained transferable Cit characters. Most of the strains transferred the Cit characters to recipient Escherichia coli more efficiently at 28 degrees C than at 37 degrees C, indicating that their transfer of the Cit character is thermosensitive. Transferred Cit characters were found in association with drug resistance markers such as ampicillin, chloramphenicol, kanamycin, streptomycin, sulfonamides, and tetracycline or with mercury resistance, but Cit plasmids conferring Cit ability alone were also obtained. Of 221 conjugative Cit plasmids tested for fertility inhibition (Fi), all but 2 were Fi- and exhibited thermosensitive transfer; 2 Cit plasmids showing the Fi+ character were also isolated from 2 S. typhimurium strains. No transferable Cit character was detected from strains of Proteus, Serratia, Klebsiella, Enterobacter, and Citrobacter spp. isolated from humans or cows in the present study. The utilization of tricarboxylic acids by strains with plasmid-borne Cit ability was examined, and two different patterns of utilization were found in the Cit+ E. coli transconjugants.

Animals↗
PubMed1980

A case of facial diplegi following herpes zoster ophthalmicus.

A 71-year-old man developed a facial diplegia following right ophthalmic zoster. Neurological examination also revealed loss of reflexes in the lower limbs with increase of CSF protein. Unusual cases of the Ramsay Hunt syndrome and Guillain-Barré syndrome seen with herpes zoster were reviewed. These cases including our case may suggest that the bilateral involvement or its wider spread throughtout nervous tissue can rarely occur in the Ramsay Hunt syndrome and its subgroups.

Aged↗