PubMed Health⌕ Search

Biomedical subjects

M Hibi

Publications and source records attributed to M Hibi.

125 records · Page 7Linked to original sources
PubMed1986

Antimutagenicity of extracts from crude drugs in Chinese medicines.

The antimutagenicity of extracts from crude drugs was studied by the Ames bioassay system. The crude drugs chosen were medical plants used very frequently as Chinese medicines. Each crude drug was extracted with hot water similar to the method of Chinese medical treatment. Antimutagenicity of the extract was found with 4 kinds of crude drugs, Paeoniae radix, Bupleuri radix, Hoelen and Glycyrrhizae radix. Each extract of the crude drug showed a different type of antimutagenic action from the others.

Humans↗
PubMed1983

[Clinical study of diffusion of cefotiam into myocardial tissue].

In 11 patients undergoing open-heart operation, 1 g of cefotiam (CTM) was administered intravenously by bolus technique at the start of operation. Samples of serum were obtained at 30, 60 and 90 minutes following administration. Samples of right atrial appendage tissue and serum were obtained simultaneously at the time of heart cannulation. Antibiotic concentrations of all samples were determined by agar well method using P. mirabilis ATCC21100 as the test organism. The results were as follows: Serum levels of CTM after 30, 60 and 90 minutes were 53.1 +/- 17.6 micrograms/ml (Mean +/- S.D., n = 10), 26.1 +/- 10.4 micrograms/ml (n = 11) and 13.5 +/- 5.5 micrograms/ml (n = 7) respectively. Myocardial tissue levels of CTM after 60 and 90 minutes were 9.4 +/- 4.7 micrograms/g (n = 4) and 4.8 +/- 2.7 micrograms/g (n = 7) respectively. The concentration ratios of the myocardial tissue to serum were 0.36 +/- 0.10 (n = 4) after 60 minutes and 0.35 +/- 0.09 (n = 7) after 90 minutes. CTM can transmigrate from blood to myocardial tissue easily as compared with other cephalosporins. Therefore, CTM, a new broad spectrum cephalosporin, can be considered as one of the highly useful antibiotics for the prevention and treatment of infections following cardiac operation.

Adolescent↗
PubMed1983

[Nonsurgical technique for removal of catheter fragments in the heart and the great vessels].

With the widespread use of intravenous polyethylene or silicone elastomer catheters for continuous infusion of fluids and drugs and monitoring central venous pressure, loss of catheter fragments into the central circulation has become an increasing problem. These catheter fragments have been removed from all areas of the right side circulatory system by various techniques not requiring thoracotomy. Many kinds of instruments for nonsurgical removal of these fragments have been utilized. The majority of them have been accomplished using a loop snare or a helical basket. As with loop snares and baskets, a free end of fragments is necessary for fragment entrapment. In this report the authors describe four cases with catheter fragments in the heart or the great vessels and a new nonsurgical technique using a "forceps with three or two grasping prongs for endoscope" for their removal. In the first case, we could remove the embolized catheter fragment without accessible free ends in the pulmonary artery by this method. This special forceps with two grasping prongs was applicable even for the infant and could be inserted through a No. 8 French Cordis catheter introducer. This method is extremely promising for removal of catheter fragments in the central circulatory system.

Adult↗
PubMed1982

Studies on an anti-inflammatory agent. III. Pharmacological investigations of a new non-steroidal anti-inflammatory agent: 2-oxo-3-[4-(1-oxo-2-isoindolinyl)-phenyl]-butanamide (GP 650).

The anti-inflammatory, analgesic, antipyretic and ulcerogenic activities and acute toxicity of 2-oxo-3-[4-(1-oxo-2-isoindolinyl)-phenyl]-butanamide (GP 650) were investigated in laboratory animals and compared with those of phenylbutazone, acetylsalicylic acid (ASA), ibuprofen, tiaramide-HCl and tinoridine-HCl. The anti-inflammatory and analgesic activities of GP 650 were found to be almost equivalent to those of phenylbutazone on the basis of various anti-inflammatory and analgesic tests while its antipyretic activity was less marked, and its ulcerogenic action and acute toxicity were much lower than those of the other agents. It is interesting to note that GP 650 possesses marked anti-inflammatory activity similar to acidic anti-inflammatory agents in chronic inflammatory models along with mild antipyretic and ulcerogenic activities found in basic anti-inflammatory agents. Therefore, GP 650 appears to be a promising anti-inflammatory and analgesic agent.

Analgesics↗
PubMed1980

A method for evaluating analgesic agents in rats.

A method is described for evaluating antinociceptive activity in rats using writhing responses induced by 4% sodium chloride solution. Narcotic and nonnarcotic analgesics, narcotic antagonists except naloxone, and antipyretic and nonsteroidal antiinflammatory drugs were effectively evaluated at relatively low doses using this method. Parenteral ED50 values of these compounds ran parallel to their clinical doses. The method detected not only the analgesic action of the above drugs but also that of methamphetamine. In spite of its high sensitivity, the method was specific in the sense that CNS-depressant, muscle relaxant, anticholinergic, and antihistamine drugs and anesthetics were inactive even at toxic doses. On the other hand, the decrease in the analgesic activity of morphine upon chronic injection was also observed with this method. The writhing test with 4% sodium chloride in rats was concluded to be a sensitive and specific test for analgesic drugs and useful for examining changes in analgesic activity of drugs during chronic administration.

Acetates↗
PubMedDate not supplied

Vasorelaxing and receptor binding properties of NZ-105, a novel dihydropyridine derivative, in isolated rabbit aorta.

The vasorelaxing and dihydropyridine receptor binding properties of NZ-105, a new dihydropyridine derivative, were studied using isolated rabbit aorta, and compared with those of nicardipine, nifedipine and diltiazem. NZ-105 (3 x 10(-10)-3 x 10(-9) M), nicardipine (3 x 10(-10), 10(-9) M), and diltiazem (3 x 10(-7), 10(-6) M) selectively relaxed aortic strips precontracted with high-K+ solution (50 mM) with little effect on strips precontracted with phenylephrine (10(-5) M) or clonidine (10(-6) M). The relaxation produced by NZ-105 was of very slow onset, and no recovery was observed after a 2 hr washout with high-K+ or normal bathing solution. NZ-105 (3 x 10(-10)-3 x 10(-9) M) caused a non-parallel depression of the concentration-response curve for the CaCl2-induced contraction in high-K(+)-depolarized rabbit aorta, whereas nicardipine (10(-10), 3 x 10(-10) M), nifedipine (10(-9), 3 x 10(-9) M) and diltiazem (10(-7), 3 x 10(-7) M) all produced a concentration-related rightward displacement of the curve. The depression induced by NZ-105, but not by nicardipine, became greater as the period of preincubation with the drug was prolonged. NZ-105, nicardipine and diltiazem, at the very high concentration of 10(-6) M, caused a slight and noncompetitive inhibition of the concentration-response curves for norepinephrine, prostaglandin F2 alpha, angiotensin II and 5-hydroxytryptamine. NZ-105 displaced 3H-nitrendipine binding to rabbit aortic membranes in a manner similar to that of nicardipine and nifedipine, and this was also incubation time-dependent. These results indicate that NZ-105 possesses selective calcium antagonist properties, with respect to the rabbit isolated vascular smooth muscle, which are of very slow onset and long-lasting. The slow onset of the vasorelaxation may be due to a slow association rate to dihydropyridine receptors. These pharmacological properties of NZ-105 may, at least in part, be responsible for the slow onset and long duration of its antihypertensive action in vivo.

Angiotensin II↗
PubMedDate not supplied

Cardiac and vascular effects of NZ-105, a novel dihydropyridine derivative, in vitro.

The cardiovascular selectivity of NZ-105, a novel dihydropyridine derivative, was studied in vitro in comparison with nicardipine and other calcium antagonists. NZ-105 and nicardipine (10(-9), 10(-8) M) decreased the spontaneous contraction rate of the isolated guinea-pig right atrium. On the other hand, NZ-105, even at concentrations as high as 10(-6) M, slightly diminished the contractile force of the electrically driven left atrium, while nicardipine strongly and dose-dependently decreased the contractile force at a concentration of 10(-7) M by 39.9% and at 10(-6) M by 72.1%. NZ-105, nicardipine and diltiazem, at concentrations below 10(-6) M, caused no or only a slight depression of isoproterenol-induced increases in the contractile force of the driven left atrium. In left atrium partially depolarized with high K+ (22 mM) in the presence of 10(-6) M of isoproterenol, NZ-105 (10(-8)-10(-6) M), nicardipine (10(-9)-10(-7) M) and diltiazem (10(-7), 10(-6) M) produced both a concentration-related displacement of the concentration-response curves for CaCl2 to the right and a depression of the maximum response to CaCl2. In various rabbit blood vessels depolarized with high K+ (100 mM) (coronary, superior mesenteric, renal and femoral arteries and saphenous vein). NZ-105 (3 x 10(-10)-10(-8) M) caused a non-parallel depression of the concentration-response curves for CaCl2-induced contractions. The calcium-antagonizing effect of NZ-105 was strongest in the basilar artery. NZ-105 displaced the [3H]-nitrendipine binding to rabbit cardiac and aortic membranes in a manner similar to nicardipine and nifedipine. The Ki values of these compounds, with respect to cardiac membranes, were several times larger than in the case of aortic membranes. The Ki value of NZ-105, but not of nicardipine, grew smaller as the preincubation period with the drug increased. These findings indicate that NZ-105 possesses selective calcium-antagonizing properties in vascular smooth muscle, especially in the basilar artery, when compared with cardiac muscle. The negative chronotropic action of NZ-105 was more potent than its inotropic action. On the basis of these pharmacological properties, NZ-105 is considered to be a useful drug for the treatment of cardiovascular disorders.

Animals↗
PubMedDate not supplied

Antihypertensive and diuretic effects of NZ-105, a novel dihydropyridine derivative.

Studies on the antihypertensive and diuretic actions of NZ-105, a new dihydropyridine derivative, were performed in comparison with nicardipine. NZ-105 and nicardipine (5, 10 and 20 mg/kg, p.o.) dose-dependently decreased systolic blood pressure in three types of experimentally hypertensive rats, including spontaneously hypertensive rats, renal hypertensive rats and deoxycorticosterone acetate-salt hypertensive rats and normotensive Wistar-strain rats. The hypotensive effects were larger in hypertensive rats than in normotensive Wistar rats. The hypotensive actions of NZ-105 were very slow in onset and long-lasting in all models, e.g., the hypotension by NZ-105 (10 mg/kg, p.o.) reached a peak (-52 mmHg) at 3 hr and lasted for more than 9 hr in spontaneously hypertensive rats. The hypotensive action in spontaneously hypertensive rats was reproducible after repeated dosing twice a day for 29 days. The hypotensive action after i.v. injection of NZ-105 (0.1 mg/kg) in spontaneously hypertensive rats was also slow in onset (peak time: 10 min) and long-lasting (more than 120 min). The hypotensive potency of NZ-105 was about the same as that of nicardipine, but the increment in heart rate was smaller than in the case of nicardipine. Both NZ-105 and nicardipine showed diuretic and natriuretic actions in spontaneously hypertensive rats. After repeated administration, these actions of NZ-105 were unchanged, whereas those of nicardipine were reduced. These results suggest that NZ-105 is a useful antihypertensive drug with concomitant diuretic effects.

Animals↗