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Lindvall K, Cocco G, Wendt G, Chu D, Heizmann P. Serial M-mode echocardiography in evaluation of the cardiovascular effects of tiapamil and their relationship to plasma levels in patients with coronary heart disease. Int J Cardiol 1981; 1:15-24. [PMID: 7333712 DOI: 10.1016/0167-5273(81)90042-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Tiapamil (Ro 11-1781) is a new calcium antagonist. Several investigators have reported about its efficacy against cardiac arrhythmias and angina pectoris. However, there was no study that assessed a possible relationship between hemodynamic effects and plasma concentration. Our study was aimed to investigate any possible relationship between cardiovascular effects of tiapamil and its plasma concentration. We selected 8 coronary; patients (6 males and 2 females) with a mean age of 61.9 yr and a mean weight of 70.9 kg. Tiapamil was administered per os at the dose of 250 mg t.i.d. for 4 consecutive days. Hemodynamic data were obtained by means of echocardiography, ECG and sphygmomanometry. Plasma concentrations of Ro 11-1781 and its major metabolites were measured by means of high pressure liquid chromatography. With tiapamil, the morning systolic BP fell from 130.6 +/- 19.5 (mean +/- SD, pretreatment) to 114.4 +/- 18.2 mm Hg on day 4, the change being clinically and statistically significant (P less than 0.02 by paired t-tests). Diastolic BP and HR remained unchanged. LVEDD and LVESD were not affected to any relevant extent, but VCF was significantly (P less than 0.05) and persistently increased. Tiapamil was well absorbed, but large interindividual variations were observed. As a general rule, no direct relationship between plasma concentrations and hemodynamic effects could be demonstrated. However, the number of patients is too small to allow general conclusions. At the above dose, tiapamil did not elicit any clinically detectable negative inotropic or negative chronotropic effect, probably because of its lowering effect on systolic BP.
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Abstract
An episode of torsades de pointes, an unusual ventricular tachyarrhythmia, developed in a 59-year-old coronary patient who was treated with 100 mg. four times a day mexiletine orally. The PR, QRS, and QT intervals were normal. The ventricular arrhythmias resembled in part, the patient's previous ventricular premature complexes, but there were some relevant morphological differences. The plasma electrolytes were within normal limits. Mexiletine, which is chemically and electrophysiologically similar to lidocaine, probably caused this arrhythmia. Although mexiletine is a useful antiarrhythmic drug, it should be added to the list of drugs associated with atypical ventricular tachycardia.
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153
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Nowak FG, Cocco G, Chu D, Gasser DF. Antiarrhythmic effect of the calcium antagonist tiapamil (Ro 11-1781) by intravenous administration in patients with coronary heart disease. Clin Cardiol 1980; 3:371-6. [PMID: 6161729 DOI: 10.1002/clc.4960030603] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Twenty coronary patients with a median age of 76 years were treated in the coronary care unit with tiapamil, a new Ca2+ antagonist, by intravenous infusion (until December, 1979, the generic name was dimeditiapramine). The following arrhythmias were identified: atrial fibrillation with ventricular rate greater than 95 beats/min (5 patients); supraventricular premature complexes (SVPC) (4 patients); and ventricular premature complexes (VPC), Lown grades 2-4 (15 patients). Electrocardiograms and hemodynamic parameters were continuously monitored prior to, during, and after the therapy. In patients with atrial fibrillation, sinus rhythm was not restored, but tiapamil decreased the ventricular rate by 54%. In patients with VPC, the median frequency of VPC decreased from 310.5 before tiapamil to 32.5 beats/h at the fourth hour of therapy (p less than 0.01). The median ectopic/sinus beat ratio decreased from 0.083 (pretreatment) to 0.008 at the fourth hour of infusion (p less than 0.10). In one of the patient with an insufficient decrease in the number of VPC, the VPOC changed from class 4a (pretreatment) to class 2 (during the therapy), returning to class 4a after the infusion was stopped. Tiapamil reduced the median systolic and diastolic blood pressures by 8.3 and 7.1%, respectively (p less than 0.05), the third hour. Hypotension and bradycardia were observed in 5/20 patients. The results show that tiapamil is effective against both supraventricular and ventricular arrhythmias, and thus its spectrum of action differs from that of other calcium antagonists.
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154
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Chu D, Cocco G, Schweda E, Haeusler G, Strozzi C. Influence of propranolol and pindolol on the haemodynamic effects of papaverine, isoprenaline and noradrenaline in hypertensive patients. Eur J Clin Pharmacol 1980; 18:141-6. [PMID: 7428794 DOI: 10.1007/bf00561581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The influence of two beta-adrenoceptor antagonists, propranolol and pindolol, on the haemodynamic effects of papaverine, isoprenaline and noradrenaline was investigated in 9 male patients with first degree essential hypertension. Propranolol and pindolol were given according to a doubleblind, crossover scheme. Heart rate and blood pressure were measured before and after each treatment. Propranolol 670 microgram/kg i.v. reduced the supine and standing systolic blood pressures by 2.3% and 1.6%, respectively. Similarly, the intravenous administration of pindolol 35 microgram/kg reduced supine and standing systolic blood pressure by 5.5% and 8.3% respectively (clinically insignificant). Neither drug affected diastolic blood pressure. Following propranolol, there were moderate reduction in supine and standing heart rates, respectively by 24% and 20% (p < 0.001). Similarly, but to a lesser extent, pindolol reduced supine and standing heart rate by 12% and 17% (p < 0.001). The effects of papaverine, which, at 1.5 mg/kg i.v. reduced systolic blood pressure by 5-10% and increased heart rate by 8-15%, were not significantly influenced by the beta-blockers. The blood pressure and heart rate responses to isoprenaline, on the other hand, were attenuated or inhibited by both beta-blockers. While the beta-blockers inhibited the beta-adrenoceptor component of noradrenaline, the pressor component of noradrenaline, which is mediated through the alpha-adrenoceptors, was not influenced by propranolol, but was inhibited after pindolol. It is concluded that pindolol differs qualitatively from propranolol in that it inhibited both the alpha and beta-adrenoceptor effects of noradrenaline.
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155
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Cocco G, Strozzi C, Chu D, Amrein R, Castagnoli E. Therapeutic effects of pindolol and nifedipine in patients with stable angina pectoris and asymptomatic resting ischemia. BRITISH JOURNAL OF CLINICAL PRACTICE. SUPPLEMENT 1980; 8:59-65. [PMID: 6781520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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156
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Cocco G, Strozzi C, Haeusler G, Chu D, Amrein R, Padovan GC. The therapeutic value of clonidine in patients with coronary heart disease. EUROPEAN JOURNAL OF CARDIOLOGY 1979; 10:221-8. [PMID: 499282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
11 coronary patients, 8 with mild hypertension, were treated with clonidine, at a dose of 75 micrograms b.i.d. per os for a week. The effect of the drug on coronary heart disease was assessed by means of a symptom-limited multistage exercise test on the cycloergometer. Clonidine was effective in reducing the exercise-induced increases in blood pressure (by 15.5 +/- 6.1%), the double product (by 34.8 +/- 20.8%) and the electrocardiographic ischemic changes. In 2/4 patients, effort related ventricular extrasystoles were reduced by greater than 50% after clonidine. The drug worsened the anginal pain in 3 and relieved the pain in 3 patients. However, it reduced the exercise-induced ST-T segment downsloping in 7 patients. The tolerance was good, since only 3/11 patients reported slight dry mouth, sedation and pyrosis. In view of the electrocardiographic effect, further studies with clonidine on myocardial ischemia should be performed.
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157
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Cocco G, Strozzi C, Chu D, Amrein R, Castagnoli E. Therapeutic effects of pindolol and nifedipine in patients with stable angina pectoris and asymptomatic resting ischemia. EUROPEAN JOURNAL OF CARDIOLOGY 1979; 10:59-69. [PMID: 111940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A single blind randomized parallel study designed to assess the anti-anginal efficacy of pindolol and nifedipine was carried out in 42 ambulatory coronary patients with stable angina pectoris. Drug efficacy was assessed in terms of (a) pain, (b) frequency of anginal episodes, (c) nitroglycerin consumption, (d) exercise tolerance and (e) ST-segment changes. The effect of these drugs on asymptomatic resting myocardial ischemia was also assessed by means of 24-h dynamic electrocardiography (DCG). All patients were checked at weekly intervals. At the end of a 4-wk placebo period, the patients were randomly assigned either to the pindolol or nifedipine group. The treatment lasted for 45 days. During the placebo period, ischemic ECG changes and symptoms of coronary insufficiency were detected in all patients. Furthermore, 12 out of 42 patients had asymptomatic myocardial ischemia at rest. One patient from each group was dropped because of tolerance. At the end of the 45-day study, pindolol and nifedipine were equi-effective on spontaneous and effort-related angina. There were, however, some differences: increased tolerance to exercise appeared earlier with pindolol: the pindolol group showed a slightly reduced while the nifedipine group showed a slightly increased heart rate. Furthermore, nifedipine reduced or eliminated asymptomatic myocardial ischemia in 6 out of 7 patients while only 1 out of 5 improved in the pindolol group.
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158
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Cocco G, Strozzi C, Chu D. Human electropharmacology of the calcium antagonist dimeditiapramine (Ro 11-1781) in coronary patients. Clin Cardiol 1979; 2:212-6. [PMID: 509799 DOI: 10.1002/clc.4960020307] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The electrophysiological effect of dimeditiapramine (Ro 11-1781), a Ca2+ antagonist, was evaluated in 20 patients with coronary heart disease. Electrophysiological measurements, including sinus cycle length, sinoatrial conduction time, intra-atrial conduction time, atrial, atrioventricular, nodal and ventricular refractory periods and intraventricular conduction time were recorded before and after the intravenous administration of Ro 11-1781. At a dose which is effective against cardiac arrhythmias, Ro 11-1781 produced no statistical significant changes in the sinoatrial and intraventricular conduction time. Similarly, neither the sinoatrial nor the ventricular refractory period was affected. Ro 11-1781, however, increased the atrioventricular conduction time and decreased the systolic blood pressure to a statistically significant extent. The tolerance was very good.
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Cocco G, Chu D, Strozzi C. Dimeditiapramine (Ro 11-1781), a new calcium antagonist, in the management of supraventricular tachyarrhythmias in patients with acute myocardial infarction. Clin Cardiol 1979; 2:131-4. [PMID: 262567 DOI: 10.1002/clc.4960020208] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
18 patients with acute myocardial infarction and sustained arrhythmias were treated with a new Ca2+ antagonist, Ro 11-1781, at the dose of 1.0 mg/kg i.v. The drug was effective in reducing heart rate to less than 90 beats/min in 9/10 patients with atrial fibrillation, in 3/4 patients with atrial flutter and in 3/4 patients with supraventricular tachycardia. The peak effect was observed within 2--5 min after the intravenous administration of Ro 11-1781. In cases with recurring tachyarrhythmias, the drug was also effective in repetitive administration. Systolic blood pressure was reduced, but severe hypotension (less than 90 mm Hg) was not observed. The atrioventricular conduction in these patients remained unimpaired and asystole did not occur. The drug appears to be an effective and a well tolerated antiarrhythmic agent.
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160
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Chu D, Kaufman L, Hosier K, Hoenninger J. An evaluation of cadmium telluride detectors for computer assisted tomography. J Comput Assist Tomogr 1978; 2:586-93. [PMID: 711945 DOI: 10.1097/00004728-197811000-00011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cadmium telluride (CdTe) presents a set of extremely attractive features as an X-ray detector for computer assisted tomography (CAT). It is stable and easily handled; has a high detection efficiency and very efficient conversion of energy to charge; and permits a high element density in a compact configuration. Unfortunately, effects due to "polarization," "tailing," high and variable leakage currents, and long "memory" are incompatible with the needs of CAT instrumentation. Pulse-processing techniques have allowed us to eliminate these problems in positive-sensitive detectors, thus opening the way for utilization of CdTe in CAT.
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161
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Perez-Mendez V, Lim C, Ortendahl D, Semper R, Cheng A, Chu D, Hattner R, Kaufman L, Price D. Two detector MWPC positron camera with honeycomb lead converters for medical imaging: Performance and developments. ACTA ACUST UNITED AC 1978. [DOI: 10.1016/0029-554x(78)90688-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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162
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Cocco G, Burkart F, Chu D, Follath F. Intrinsic sympathomimetic activity of beta-adrenoceptor blocking agents. Eur J Clin Pharmacol 1978; 13:1-4. [PMID: 25186 DOI: 10.1007/bf00606672] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The pharmacological methods used to assess the intrinsic sympathomimetic activity (ISA) of beta-blockers are discussed. The clinical relevance of ISA to respiratory function, peripheral resistance and cardiac function is reviewed. It appears doubtful whether ISA is always of predominant clinical significance and an alternative explanation is offered for many clinical effects observed with certain beta-blockers, e.g. pindolol, oxprenolol, tolamolol, metoprolol, etc. Some effects of these beta-blockers resemble those of labetalol, a new drug with both alpha and beta-blocking activity. Some clinical effects of certain beta-blockers are more likely to be due to alpha-blocking activity than to their ISA.
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163
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Chu D, Kovacs BA. Anti-inflammatory activity in oak gall extracts. ARCHIVES INTERNATIONALES DE PHARMACODYNAMIE ET DE THERAPIE 1977; 230:166-76. [PMID: 603307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A method for the purification of the Hungarian oak gall extracts containing anti-inflammatory activity is described. The anti-inflammatory activity of the purified extract was tested in the carrageenan-induced rat paw edema and in rat polyarthritis induced by mycobacterial adjuvant. In doses of 4.3 and 8.5 mg/kg i.p., the extract inhibited dose-dependently the formation of paw edema induced by carrageenan in rats. When rats were treated daily from 3 days prior to and 16 days after the injection of the mycobacterial adjuvant, the severity of the polyarthritic symptoms was significantly reduced.
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164
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Jorgenson T, Newell G, Scharpf L, Gribling P, O'Brien M, Chu D. Study of the mutagenic potential of nitrilotriacetic acid (NaCaNTA) in mice by the translocation test. ACTA ACUST UNITED AC 1975. [DOI: 10.1016/0165-1161(75)90151-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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165
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Strozzi C, Cocco G, Chu D. The kinetocardiogram and dopamine in the assessment of coronary heart disease. CURRENT THERAPEUTIC RESEARCH 1975; 18:261-75. [PMID: 809239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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166
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Chu D, Chan TH, Kovacs BA. Biologically active substances in oak gall extracts. Part 1: Isolation and chemical identification of a substance exerting antihistamine-like activity (KC-18). ARCHIVES INTERNATIONALES DE PHARMACODYNAMIE ET DE THERAPIE 1975; 214:141-54. [PMID: 239648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The previously reported antihistamine-like activity of partially purified oak gall extracts has been confirmed. Isolation of the active principle was achieved through the use of organic solvent extractions and column chromatographic (Sephadex LH-20 and silica gel) procedures. Preliminary investigation on the structure of this chemically pure substance using mass spectrometry, thin layer chromatography, base hydrolysis and electrophoresis indicated that it is most probably an ester of piperonylic acid. KC-18, given intraperitoneally in doses of 4 mg/kg to guinea pigs 5 hours prior to an exposure to a 0.15 per cent histamine aerosol, significantly reduced the bronchoconstrictor effect of histamine.
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167
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Chu D, Kovacs BA. Biologically active substances in oak gall extracts. Part 11. The antihistamine-like activity of a substance (KC-18) isolated from oak gall extracts. ARCHIVES INTERNATIONALES DE PHARMACODYNAMIE ET DE THERAPIE 1975; 214:155-64. [PMID: 239649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The effects of the newly isolated antihistamine (KC-18) from the Hungarian oak gall extracts on some actions of histamine have been investigated. Intraperitoneally administered KC-18 into guinea pigs and cats in doses of 2.5-16 mg/kg exerted a significant dose-related inhibition of histamine-induced bronchoconstriction, increase in capillary permeability and hypotension. In guinea pigs, actively sensitized with ovalbumin, 4 mg/kg KC-18 administered intraperitoneally prevented the development of anaphylactic shock following antigenic challenge. Histamine-induced gastric acid secretion in the rat was also dose-relatedly reduced by the intravenous administraton of 72 and 120 mg/kg KC-18. However, KC-18 in doses up to 100 mug/ml did not modify the histamine-induced contraction of the isolated guinea pig ileum.
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168
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Chu D, Gregeen R, Stürmer E, Berde B. Proceedings: Actions of prostaglandins A2, E1 and F2alpha on cat skeletal muscle vascular bed. Br J Pharmacol 1974; 52:112P-113P. [PMID: 4451773 PMCID: PMC1776951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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169
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Chu D, Stuermer E, Berde B. Studies on the mechanism of action of dihydroergotamine (DHE) on the vascular bed of cat skeletal muscle. Br J Pharmacol 1973; 48:331P-332P. [PMID: 4733740 PMCID: PMC1776236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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170
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Smith RB, Craig HM, Chu D. Fungal deterioration of second-growth Douglas-fir logs in coastal British Columbia. ACTA ACUST UNITED AC 1970. [DOI: 10.1139/b70-231] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fungal deterioration of second-growth Douglas-fir logs, felled each month from August 1961 to May 1962, was studied 2, 4, and 6 years after felling. Decay increased from 10% of log volumes after 2 years to 47% after 6 years. The rate of decay, particularly for the brown cubical type, was greater for autumn- and winter-felled logs than for those felled in the spring and late summer, and closely paralleled the seasonal pattern of ambrosia beetle attack.Decay rates increased with decreasing log size, increasing percentage of sapwood, and increasing height of log above ground. For the same diameter of log, base logs decayed less rapidly than second logs, possibly because of their lower proportion of sapwood in relation to heartwood.Decay expressed as a percentage of total log volume (Y) may be estimated (R2 = 0.71) with the following equation: Y = 13.2 + 10.7X1 − 3.2X2, where X1 = years elapsed and X2 = d.i.b. (diameter inside bark) top of log.Of 30 wood-decay fungi isolated, Naematoloma sp. (N. capnoides or N. fasciculare), which causes a white rot, was associated with the most decay. Fomes pinicola was mainly responsible for brown cubical sap rot, while Poria monticola and P. carbonica caused a brown cubical heart rot at the ends of logs.The significance of variations in deterioration rate and fungal associates is discussed in relation to log durability and salvability.
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171
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Chu D, Windheuser JJ. Interference of polycarboxylic acids in the determination of ester degradation by the hydroxamic acid procedure. J Pharm Sci 1970; 59:130-1. [PMID: 5411320 DOI: 10.1002/jps.2600590133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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172
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Kozam RL, Conklin EF, Giannelli S, Serey P, Chu D. Open-heart surgery for mitral stenosis during pregnancy. J Thorac Cardiovasc Surg 1967; 53:587-91. [PMID: 6022416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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