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Biomedical subjects

H Hashimoto

Publications and source records attributed to H Hashimoto.

At least 1,297 records · Page 72Linked to original sources
PubMed1982

Effects of dibutyryl cyclic AMP on patients with severe heart failure.

Dibutyryl cyclic AMP was administered to 2 patients with severe congestive heart failure. After an intravenous drip infusion of dibutyryl cyclic AMP (300 mg/40 min), marked diuresis and mild improvement of the patients' physical activity occurred. The cardiac index increased and both systemic vascular resistance and pulmonary capillary wedge pressure decreased. Blood glucose and plasma insulin increased simultaneously, while plasma free fatty acid decreased during the infusion. A continuous intravenous micro-infusion of dibutyryl cyclic AMP (300 mg/24 h) also exerted diuresis and improved physical activity. The hemodynamic and metabolic effects of dibutyryl cyclic AMP are expected to be beneficial to a failing heart.

Adult↗
PubMed1982

SG-75 induction of increased coronary outflow and PGE1 from ischemic areas in dogs with experimental myocardial infarction.

We measured the coronary blood flow and concentrations of prostaglandin E1(PGE1), PGF2 alpha, and lactate from the ischemic myocardium of dogs treated with either SG-75 or indomethacin. There was a significant increase of coronary blood outflow from the ischemic myocardium after ligation in dogs given SG-75 and in control dogs compared with indomethacin-treated dogs. The release of lactate from the ischemic myocardium decreased significantly in dogs with SG-75 compared with the indomethacin and control group. The concentration of PGE1 rose significantly after ligation in dogs with SG-75 compared indomethacin-treated and those in control dogs. A significant release of PGE1 from the ischemic area of the myocardium treated with SG-75 was clearly demonstrated at 60 min after ligation of the LAD coronary artery. Also, a significant release of PGF2 alpha from the ischemic area of the myocardium was demonstrated at 15 min after ligation. There was a significant correlation between the increase of coronary outflow and PGE1 release from the ischemic myocardium ( 4= 0.70, p less than 0.01). However, no significant correlation was demonstrated between the increase of coronary outflow and PGF2 alpha. These results show a close relation ship between increased coronary outflow induced by SG-75 and increased release of PGE1. Thus, a beneficial effect of SG-75 on the ischemic myocardium was demonstrated.

Alprostadil↗
PubMed1982

Effects of thymoxamine on ouabain-induced arrhythmias in dogs.

The effect of thymoxamine, a pure alpha-adrenoceptor blocking agent, on ouabain-induced arrhythmias was investigated in dogs to clarify whether thymoxamine has an arrhythmogenic or an anti-arrhythmic action. Thymoxamine. 1 mg/kg i.v., inhibited the manifestation of ventricular arrhythmias (VA) and the pressor effect produced by ouabain infusion (1 microgram/kg/min i.v.) as 5 mg/kg i.v. of phentolamine did. Low doses of these drugs did not affect the VA. Simultaneous infusion of phenylephrine (5 micrograms/kg/min i.v.) with ouabain enhanced the manifestation of VA accompanying pressor effects, which were inhibited by thymoxamine (1 mg/kg) in a parallel manner. Infusion of isoprenaline (0.2 microgram/kg min i.v.) with ouabain enhanced the manifestation of VA, but the enhancement was to a lesser extent than with phenylephrine. Thymoxamine, 1 mg/kg, did not affect the VA. The infusion of CaCl2 (20 mg/kg/min i.v.) with ouabain enhanced the manifestation of VA, which was not inhibited by thymoxamine. These results show the possibility that the protective effect of thymoxamine on the manifestation of VA may be mainly associated with inhibitions of pressor effects mediated through vascular alpha-adrenoceptors.

Animals↗
PubMed1982

AM-2604 A, a new antiviral antibiotic produced by a strain of Streptomyces.

A novel antibiotic, AM-2604 A was isolated from the fermentation broth of Streptomyces sp. AM-2604 by solvent extraction and silica gel column chromatography. The antibiotic is pale yellow needles possessing UV absorption maxima at 280 nm and 330 nm (sh). The antibiotic possesses weak activity against fungi and trichomonad and potent inhibitory activity against various RNA and DNA viruses in vitro.

Animals↗
PubMed1982

Liposarcoma. A clinicopathologic subtyping of 52 cases.

Fifty-two cases of liposarcoma were analyzed clinicopathologically, and were grouped into the following five types: myxoid (28 cases), well-differentiated (14 cases), pleomorphic (4 cases), round-cell (3 cases), and mixed (3 cases). Three of the 28 myxoid tumors showed a pleomorphic pattern resembling that of the myxoid variant of malignant fibrous histiocytoma, and one of the 3 round-cell tumors was considered to be a malignant counterpart of hibernoma. Ages ranged from 22 to 86 years with the average age of 49 years, the average patients with myxoid or round-cell liposarcoma being over 10 years younger than those with well-differentiated or pleomorphic liposarcoma. There was also a variation in the site of predilection of the cases: the great majority of myxoid type tumors occurred in the thigh, popliteal fossa and buttock (23 cases), while the majority of well-differentiated type tumors were seen in the retroperitoneum (10 cases). The rate of local recurrence of the tumor was 46%. Four of the 5 well-differentiated liposarcomas which recurred exhibited dedifferentiated pleomorphic components resembling those in malignant fibrous histiocytoma. The prognosis was more favorable in patients with ordinary myxoid tumors than in those with well-differentiated tumors. The overall relative five-year survival rate was 63%.

Adult↗
PubMed1982

Clinical effectiveness of niludipine in patients with ischemic heart disease.

The antianginal efficacy of niludipine (Bay a 7167), a new calcium antagonistic drug, was investigated in 51 patients with ischemic heart disease. 16 patients were diagnosed as effort angina and 31 patients had both angina at rest and on effort. Six anginal patients had myocardial infarction. One patient was diagnosed as a variant form of angina and 3 others as unstable angina. 11 patients had essential hypertension. 49 completed the study and 2 dropped out. Niludipine (60 mg to 80 mg every 24 h) significantly reduced the mean weekly rate of angina attacks from 6.5 to 2.2 (p less than 0.001). Marked reductions of nitroglycerin requirement were also noted (p less than 0.001). In 71% of the patients complete control of anginal attacks was achieved, and in over 77% the frequency of angina was reduced by at least 50%. Niludipine was at 93.8% effective in patients with ischemic heart disease. It decreased significantly both systolic and diastolic blood pressure in angina patients with essential hypertension, but there were no significant changes of blood pressure in normotensive anginal patients. The agent was tolerated very well and there were no side effects. These findings suggest that niludipine is a highly effective drug for the treatment of both ischemic heart disease and essential hypertension.

Adult↗
PubMed1982

Pharmacological effects of several drugs on the myoepithelium and the vascular smooth muscle of the lactating mammary gland in goats.

The present experiments were performed to investigate whether the responses of the myoepithelium to several drugs would be of a parallel nature with those of the vascular smooth muscle in the lactating mammary gland of goats. The drugs were injected into the mammary artery. Kallikrein, bradykinin, oxytocin, and acetylcholine caused marked milk-ejection with vasodilation in a dose-dependent manner. Marked milk-ejections with high doses of oxytocin were observed despite of accompanying vasoconstriction. The relative order of their potency in milk-ejection activity was kallikrein greater than bradykinin greater than oxytocin greater than acetylcholine: 1 greater than 1/100 greater than 3/1000 greater than 5/1000000. As for the vasodilator activity, the relative potency of the drugs was in the same order: 1 greater than 1/10 greater than 1/1000 greater than 1/10000. Catecholamines, histamine, serotonin, angiotensin-II, vasopressin and high doses of prostaglandin E2 caused dose-dependent vasoconstriction. Isoprenaline, pilocarpine, adenosine, PGI2 and low doses of PGE2 caused dose-dependent vasodilation. But these drugs did not affect milk-ejection. PGE1 decreased milk-ejection and was accompanied by vasodilation. From these experiments it is suggested that the relative order of the potency of secretagogues in milk-ejection activity and in vasodilator activity is nearly equal. It is also suggested that some drugs are different in their effects on the myoepithelium and on the vascular smooth muscle of the lactating mammary gland.

Acetylcholine↗
PubMed1981

Phase I study of ceftizoxime, a new cephalosporin. Single-dose study.

A phase I study of ceftizoxime, a new cephalosporin, was performed in 29 subjects. No abnormalities were observed in subjective symptoms, laboratory test results, or physical test results at estimated therapeutic doses of 500 mg intramuscularly, 500 and 1000 mg intravenously, and 2000 mg drip infusion. It is concluded, therefore, that the drug is safe for clinical use. The mean peak serum concentration was dose dependent. The mean serum concentrations of ceftizoxime in man at 5 minutes after 500 and 1000 mg by intravenous bolus were 58.4 and 112.8 micrograms/ml, respectively, which exceed the MIC80 against most pathogens tested. Thus, 500 or 1000 mg was estimated to be the therapeutic dose. The distribution volume of ceftizoxime was 16.0 to 18.6 liters, the total clearance was 135.6 to 154.9 ml/min, and the half-life in the beta-phase was 1.36 to 1.39 hours. Ceftizoxime is mainly excreted in the urine as unchanged drug, at an excretion rate in the 24-hour urine of approximately 80 per cent.

Adult↗
PubMed1981

Recurrent malignant fibrous histiocytoma. A histologic analysis of 50 cases.

This clinicopathologic study deals with 84 patients who had recurrent malignant fibrous histiocytoma (MFH), and is primarily concerned with 50 cases in which specimens of both the initial and recurrent tumors were available for histopathologic examination. Quantitative and qualitative differences in the histologic patterns characterizing MFH, such as storiform and myxoid, between the initial and recurrent tumors, were clear-cut in nearly two-thirds of the cases. Conversion in histologic subtypes of MFH occurred in nine cases, including six cases which converted from myxoid to nonmyxoid pleomorphic. The superficially located tumors recurred somewhat more frequently, but in such cases, there was a significantly better prognosis than was seen with the deeply located tumors. Changes in the degree of mitotic rate, nuclear atypism, and cellularity from the initial to the recurrent tumor correlated better with the biological behavior of the tumor than did the degree in the initial tumor itself. The increased proportion of histiocyte-like tumor cells in the recurrent tumor was another morpholic feature which indicated a much poorer prognosis than did the increased proportion of fibroblast-like tumor cells.

Adolescent↗
PubMed1981

Effects of calcium antagonists on the alternation of the ST-T complex and associated conduction abnormalities during coronary occlusion in dogs.

1 The effects of Ca2+ -antagonists on the relationships between alternate changes in the ST-T complex in the epicardial electrogram, ST-T alternans, and associated excitation-conduction abnormalities during coronary occlusion were examined in anaesthetized dogs. 2 Epicardial unipolar electrograms, bipolar electrograms (BPEG) and monophasic action potentials (MAP) were recorded with unipolar, composite and suction electrodes, respectively. 3 ST-T alternans was associated with serious conduction delay. During the period of ST-T alternans, the amplitude of MAP changed alternately and the negative deflection of the ST-T complex was associated with a larger MAP. A depression of the TQ level and decrease in the resting potential of MAP were marked. 4 Verapamil (0.2 mg/kg) and diltiazem (0.5 mg/kg) inhibited ST-T alternans, conduction abnormalities, TQ depression and changes in MAP. However, after these drugs, the TQ depression and the decrease in the resting potential were evident after a longer period of occlusion at a time when ST-T alternans, conduction abnormalities and alternate changes in MAP were still inhibited. Dipyridamole (0.5 mg/kg) had no effect on either ST-T alternans or the conduction abnormalities. 5 Verapamil and diltiazem inhibited ST-T alternans and the associated excitation and conduction abnormalities. The effects of these two drugs cannot be explained on the basis of attenuation of the decrease in the resting potential.

Action Potentials↗
PubMed1981

A mutant defective in partitioning of composite plasmid Rms201.

Escherichia coli harboring mutant plasmids defective in maintenance stability (from the conjugative plasmid Rms201) showed a wide distribution of ampicillin resistance levels, as well as increased frequency of plasmid loss from the cell. The amounts of covalently closed circular deoxyribonucleic acid of mutant plasmid Rms268 and parental plasmid Rms201 per chromosome were 5.3 and 6.1%, respectively. The beta-lactamase activities of strains W3630(Rms268) and W3630(Rms201) were 0.56 and 0.44 U/mg of protein, respectively. Frequency of plasmid loss from W3630(Rms268) was about 0.8 to 1.2% per cell generation, 100 times more than that of the wild-type strain. Ampicillin resistance levels of the colonies harboring the mutant plasmid showed a wide distribution, from low (100 micrograms/ml) to high (1,600 micrograms/ml). A miniplasmid (pMS268) with a mass of 7 X 10(6) daltons and encoding ampicillin resistance was isolated from Rms268. Frequency of pMS268 loss from W3630(pMS268) was about 0.8 to 1.9% per cell generation. W3630(pMS268) also showed a wide range of distribution in the levels of ampicillin resistance. These results indicated that the copies of Rms268 in E. coli did not segregate evenly between daughter cells at cell division and that the gene involved was located on the miniplasmid.

Ampicillin↗