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PubMedDate not supplied

Comparative effects of therapy with captopril and digoxin in patients with mild to moderate heart failure. The Captopril-Digoxin Multicenter Research Group.

This multicenter, double-blind, placebo-controlled study compares the effects of captopril treatment with those of digoxin treatment during maintenance diuretic therapy in patients with mild to moderate heart failure. Compared with placebo, captopril therapy resulted in significantly improved exercise time (mean increase, 82 s vs 35 s) and improved New York Heart Association class (41% vs 22%), but digoxin therapy did not. Digoxin treatment increased ejection fraction (4.4% increase) compared with captopril therapy (1.8% increase) and placebo (0.9% increase). The number of ventricular premature beats decreased 45% in the captopril group and increased 4% in the digoxin group in patients with more than ten ventricular premature beats per hour. Treatment failures, increased requirements for diuretic therapy, and hospitalizations were significantly more frequent in patients receiving placebo compared with those receiving either active drug. Transitory hypotension occurred more frequently with administration of captopril. Captopril treatment is significantly more effective than placebo and is an alternative to digoxin therapy in patients with mild to moderate heart failure who are receiving diuretic maintenance therapy.

Captopril↗

PubMed1986

Comparative effects of glucocorticoids and prostaglandins on small intestine of infant rats.

Previous studies have suggested similarities between the effects of exogenously administered glucocorticoids and prostaglandins in the developing rat small intestine. In this study the effects of exogenously administered glucocorticoids and prostaglandins were compared. In addition, the effects of prostaglandins in adrenalectomized rats were evaluated. Members of both classes of compounds stimulate small intestinal disaccharidase activities, and increase RNA to DNA ratio and brush border membrane protein synthesis. Hydrocortisone accelerates enterocyte turnover, whereas prostacyclin does not. Enteral administration of 16,16-dimethyl prostaglandin E2 stimulates disaccharidase activities in intact as well as sham-operated and adrenalectomized animals. The data suggest that certain prostaglandins may play a role in small intestinal metabolism which is similar to that of the glucocorticoids but is independent of the adrenal-intestinal axis.

16,16-Dimethylprostaglandin E2↗

PubMed1977

Comparative effect of anaerobic coryneforms on a murine melanoma.

Ten strains of anaerobic Corynebacteria were compared in their effect on survival of C57BL/6 mice, bearing subcutaneously inoculated B16 melanomas. The corynebacterial suspensions were injected intralesionally twice weekly for five injections. Significant permanent tumor regression was not obtained. Significant prolongation of survival was observed in mice treated with seven of the corynebacterial strains.

Animals↗

PubMedDate not supplied

Comparative effects of nitrendipine and verapamil on neuroeffector transmission in the rabbit ear artery.

The purpose of the present study was to evaluate and compare the effects of the calcium antagonists nitrendipine and verapamil on nerve-evoked constrictions and on norepinephrine (NE) release in the isolated, perfused rabbit ear artery. The response of the ear artery to nerve stimulation consists of an early phasic constriction (P response) and a late, slow-developing tonic constriction (T response). Both calcium antagonists were much more potent in causing inhibition of the T than P responses. For nitrendipine the EC50 (6.6 +/- 2.3 X 10(-8)M) for inhibition of T response was 450 times lower than the EC50 for inhibition of P response. Verapamil exhibited less selectivity for T response: the EC50 for inhibition of T response was 17 times lower than the EC50 for inhibition of the P response. Nitrendipine (3.3 X 10(7) to 3.3 X 10(-5) M) did not alter the nerve-evoked release of [3H]NE from arteries preincubated with [3H]NE. Verapamil at 3.3 X 10(-6) and 3.3 X 10(-5)M enhanced both spontaneous and nerve-evoked [3H]NE release.

Animals↗

PubMed1988

Comparative effects of rifabutin and rifampicin on hepatic microsomal enzyme activity in normal subjects.

The comparative enzyme inducing effects of rifabutin and the chemically related drug rifampicin have been investigated in 8 normal subjects. Rifampicin 600 mg daily for 7 days caused considerable shortening of the antipyrine half-life and a marked increase in antipyrine clearance, associated with an increased rate of conversion to norantipyrine and, to a lesser extent, 4-hydroxyantipyrine and 3-hydroxymethylantipyrine. The urinary excretion of 6-beta-hydroxycortisol was also markedly increased, while plasma GGT activity showed only a slight albeit statistically significant elevation. In the same subjects, rifabutin in the proposed therapeutic dosage (300 mg daily) for 7 days also enhanced the metabolic elimination of antipyrine, with preferential stimulation of the demethylation pathway, and increased the excretion of 6-beta-hydroxycortisol, but the magnitude of the effects was significantly less than after rifampicin. No significant change in plasma GGT was seen. The results indicate that, contrary to the findings in animals, rifabutin does have enzyme inducing properties in man, although at the dosages assessed they were considerably less than those of rifampicin.

Adult↗

PubMed1991

A field trial on the comparative effectiveness of malathion and Resigen by ULV application on Aedes aegypti.

Field trials were conducted in two residential areas of Petaling Jaya Municipality to test the adulticidal and larvicidal effects of malathion 96% TG and Resigen on Aedes aegypti. Malathion is the currently used insecticide in Malaysia for the control of dengue. The Leco HD ULV machine was used throught the trials. For malathion the flow rate was 90 ml/minute at a vehicle speed of 8kph and for Resigen the flow rate was 200 ml/minute at the same vechicle speed. Malathion was more effective giving higher mortality rates when compared with Resigen. The mortality rate of adult Ae. aegypti outdoor was higher than in the living room and kitchen. Both insecticides did not show promising larvicidal effects.

Aedes↗

PubMed1989

Comparative effects of hypoxia and ischemia in the isolated, blood-perfused dog heart: evaluation of left ventricular diastolic chamber distensibility and wall thickness.

To compare the effects of hypoxia and ischemia on left ventricular (LV) diastolic function, we studied 17 isolated, isovolumic dog hearts by measuring LV diastolic chamber distensibility (LV end diastolic pressure at constant volume), wall thickness, and myocardial pH in response to hypoxia at constant coronary flow or pressure versus global ischemia (zero coronary blood flow). Hypoxic perfusates consisted of methemoglobin-containing red blood cells suspended in lactated Ringer's solution. Brief cross-clamping of the coronary perfusion line was used to assess the contribution of coronary turgor to chamber distensibility and wall thickness. With hypoxia, left ventricles showed a significant early (5 minutes) decrease in diastolic distensibility and an increase in wall thickness, at either constant coronary perfusion pressure or flow. The increase in wall thickness was independent of hypoxia-induced changes in coronary turgor. In contrast, global ischemia produced an early increase in LV diastolic chamber distensibility and a decrease in wall thickness. When global ischemia was continued beyond 60 minutes, a decrease in LV chamber distensibility developed. This diastolic contracture was not associated with an increase in LV wall thickness. Myocardial pH decreased slightly during 15 minutes of hypoxia and markedly with 15 minutes of global ischemia. Thus, LV diastolic chamber distensibility decreased during 15 minutes of hypoxia, while an increase in distensibility was seen during global ischemia of similar duration. During hypoxia, these changes were associated with increased LV wall thickness, at either constant coronary perfusion pressure or constant coronary flow. Prolonged ischemia led to diastolic contracture without an increase in wall thickness.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Comparative effects of diltiazem sustained-release and captopril on blood pressure control and plasma lipoproteins in primary hypertension: a randomized, double-blind, crossover study.

We compared the effects of sustained-release diltiazem and captopril on blood pressure control and lipid profile. Forty-eight patients with primary hypertension were included in this randomized, double-blind, crossover study and 43 completed the trial. Following a two-to four-week placebo run-in period, each patient initially received either diltiazem (60-180 mg twice daily) or captopril (25-75 mg twice daily) for 16 weeks and then crossed over to the other drug after an interim placebo washout period. Both drugs significantly reduced systolic (SBP) and diastolic (DPB) blood pressure compared to baseline. However, supine (P less than 0.01), sitting and standing (P less than 0.05) DPB was lower with diltiazem than with captopril. Moreover, BP control (sitting DBP less than 90 mmHg) was achieved in a greater proportion of patients treated with diltiazem (63 vs 44%). Heart rate was significantly reduced (P less than 0.001) with diltiazem in all positions but was unchanged with captopril. Lipid, lipoprotein and apolipoprotein concentrations were not modified with either treatment. We conclude that both diltiazem and captopril are effective antihypertensive agents without deleterious effects on lipid metabolism. However diltiazem provides a better prolonged control of BP and may offer some advantages for patients in whom a slower heart rate would be beneficial.

Adolescent↗

PubMed1992

Comparative effects of halothane, enflurane, and isoflurane at equihypotensive doses on cardiac performance and coronary and renal blood flows in chronically instrumented dogs.

In order to compare equihypotensive effects of the three available volatile anesthetics, halothane, enflurane, and isoflurane, dogs were chronically instrumented for measurement of: arterial, left ventricular, and left atrial blood pressures; rate of rise of left ventricular blood pressure; myocardial wall thickening (pulsed Doppler); cardiac output (pulmonary artery electromagnetic flow meter); and coronary and renal blood flows (pulsed Doppler flow meters). All three anesthetics were administered on different days in random order to each dog (n = 10) at doses necessary to decrease mean arterial pressure to 70 and 45 mmHg and two intermediate arterial blood pressures. Changes in cardiac function and regional blood flows were compared to the awake resting state and between anesthetics using analysis of variance and paired t tests. All three anesthetics produced increases in heart rate and decreases in left ventricular dP/dt, myocardial thickening fraction, and stroke volume with the hypotension. The decreases in cardiac performance were similar among the anesthetics except at the high dose (mean arterial pressure = 45 mmHg). During this profound hypotension, cardiac performance was better maintained during isoflurane anesthesia and most depressed by enflurane anesthesia. Coronary and renal blood flows were well preserved with all three anesthetics even at mean arterial pressures of 45 mmHg. Our results suggest that isoflurane may be more beneficial than halothane or enflurane for producing profound intentional hypotension (less than 50 mmHg mean arterial pressure), although extrapolation from animal experiments to the clinical situation should be used with caution.

Animals↗

PubMed1977

Comparative effectiveness of nine hypnotic drugs: sleep laboratory studies.

The effectiveness of nine hypnotic drugs was compared using a standard protocol in separate sleep laboratory drug evaluation studies. All of these drugs were relatively effective in improving sleep with initial and short-term use. However, with intermediate-term use (two weeks), most of the drugs showed a marked decrease in their effectiveness. Following withdrawal, sleep was similar to baseline with most of the drugs, continued to be improved with flurazepam (Dalmane), 30 mg, and worsened beyond baseline levels with triazolam (U33030), 0.5 mg. The determination of a drug's effectiveness with continued use is most important clinically in enabling the physician to rationally and effectively use hypnotic drugs in the adjunctive treatment of insomnia.

Adult↗

PubMed1992

Comparative effects of Des Leu Angiotensin I and Angiotensin II on AVP secretion from the hypothalamoneurohypophysis and pituitary of the rat.

In the present study we compared the effects of Des Leu Angiotensin I (Des Leu AI) with Angiotensin II (AII) on the secretion of vasopressin (AVP) from the isolated hypothalamoneurohypophyseal system (HNS) and isolated posterior pituitary gland of the rat. Administration of 10(-6)M, 10(-5) M and 10(-4) M Des Leu AI was without significant effect on AVP secretion from the HNS. A similar phenomenon was seen in the posterior pituitary with 10(-6) M and 10(-5) M Des Leu AI, although 10(-4) M significantly increased AVP release. Administration of 10(-6) M AII was without significant effect in either preparation, although 10(-5) M and 10(-4) M AII caused significant dose-dependent increases in AVP secretion over control release that were similar in both the HNS and posterior pituitary gland. These results suggest that Des Leu AI is not a physiologically relevant stimulus of AVP secretion when restricted to this area of the rat brain. They are also consistent with the presence of receptors sensitive to AII in the pituitary gland of the rat.

Angiotensin I↗

PubMed1985

Comparative effects of wheat bran and barley husk on nutrient utilization in rats. 1. Protein and energy.

1. The present work with growing rats was undertaken to compare the effect of wheat bran and barley husk on nutrient bioavailability. The experiment involved a total of nine dietary treatments consisting of a control group, without wheat bran or barley husk, and two series of four groups with increasing amounts of fibre from 50 to 117 g/kg dry matter (DM) from the two fibre sources. Dietary nitrogen concentration was kept constant at 15 gN/kg DM by adjusting the diets with an N-free mixture. Protein sources were casein, fortified with methionine and white wheat flour. True protein digestibility (TD), biological value (BV), net protein utilization (NPU) and digestible energy (DE) were estimated. 2. TD decreased when total dietary fibre (TDF) increased, the effect being greater in the case of wheat bran. The difference in response can be explained by the larger N contribution from bran than from barley husk. N from barley husk was actually digested less than N from wheat bran. 3. Changes in TD due to fibre were small, both for wheat and barley husk. It was concluded that decreased TD with fibre at moderate levels was due to poor digestibility of the N associated with the fibre source rather than decreased digestibility of N from other dietary components. 4. BV was only marginally affected by the fibre levels, indicating that the relatively high lysine content in both wheat bran and barley husk had a low availability. 5. Wheat bran and barley husk showed almost the same negative effect on DE and DM digestibility (DMD). DMD correlated significantly with DE, demonstrating that DMD is a simple and convenient means of monitoring DE.

Animal Nutritional Physiological Phenomena↗

PubMed1986

Comparative effects of wheat bran and barley husk on nutrient utilization in rats. 2. Zinc, calcium and phosphorus.

1. The present work was undertaken to study comparatively the effect on mineral availability in rats of wheat bran and barley husk when supplying the same amount of dietary fibre (DF). The experiment involved a total of nine dietary treatments including a control group and two series of four groups with increasing amounts of fibre from the two sources (total DF ranging from 42 to 117 g/kg dry matter (DM]. Dietary nitrogen concentration was kept constant at 15 g N/kg DM. Zinc concentration of the diets was adjusted to the level provided by the diet with the highest wheat-bran content (21 mg/kg DM) using zinc sulphate. Other minerals were not adjusted. 2. Two experiments were performed. In Expt 1 the diets were given to 5-week-old rats during 9 d and apparent absorptions of Zn, calcium and phosphorus and the femur concentrations of Zn, Ca and P were measured. In Expt 2 the diets were given to 9-week-old rats during 12 d. Mineral concentration in femur and total and albumin-bound plasma Zn and availability of plasma Zn for enzyme reactivation were measured. 3. In the younger animals, wheat bran depressed significantly the absorption of Zn when providing 40 g DF/kg DM and absorbtion of Ca when providing 80 g DF/kg DM. Barley husk depressed significantly both the absorption of Zn and Ca already at 20 g DF/kg DM. Both fibre sources had a more negative effect on Zn than on Ca absorption. Only barley husk had a small negative effect on absorption of P. Phytate did not appear as a major factor affecting mineral absorption in barley husk. All diets containing barley husk had a very low molar ratio, phytate:Zn. 4. The age of the animals influenced the utilization of dietary minerals using femur concentration as a criterion, particularly in the case of Zn. In the younger animals the decrease in femur Zn with fibre correlated with apparent Zn absorption both with wheat bran (R2 0.986, P less than 0.01) and with barley husk (R2 0.996, P less than 0.01). In the older animals femur Zn did not change significantly with fibre. 5. In the older animals, plasma Zn, albumin-bound plasma Zn and availability of plasma Zn for enzyme reactivation were lowest with the highest addition of wheat bran.

Absorption↗

PubMed1992

Comparative effects of bilateral hand splints and an elbow orthosis on stereotypic hand movements and toy play in two children with Rett syndrome.

A single-subject rapidly alternating treatment design was used to compare the effectiveness of bilateral hand splints and an elbow orthosis in decreasing stereotypic hand behaviors and increasing toy play in 2 children with Rett syndrome. The subjects' responses were compared across three treatment conditions: no intervention, hand splints, and elbow orthosis. The order of the treatment phases was randomly selected for each subject. Data were collected in both a free-time condition and a toy-play condition; the outcome measures were stereotypic hand movements and hand-to-toy contact. Both subjects demonstrated a decrease in stereotypic hand movements and a corresponding increase in toy contact with the use of the elbow orthosis. The bilateral hand splints had no obvious treatment effect.

Child↗

PubMed1987

Comparative effects of calcium-channel blockers and beta-adrenergic blocker on early diastolic time intervals and A-wave ratio in patients with hypertrophic cardiomyopathy.

To compare the effects of calcium-channel blockers with those of beta-adrenergic blockers in patients with hypertrophic cardiomyopathy (HCM), diastolic time intervals (IIA-O time, from the second heart sound to the O point of apexcardiogram, IIA-MVO time, from IIA to the mitral valve opening, and MVO-O time, from the MVO to the O point of apexcardiogram), and A-wave ratio measured from apexcardiogram were evaluated before and after more than three months of treatment. In both groups, heart rate significantly decreased after treatment. The IIA-MVO time was not affected by either drug. The IIA-O and the MVO-O times were significantly shortened by calcium-channel blockers (from 234.6 +/- 77.4 ms to 204.6 +/- 39.2 ms; p less than 0.01, and from 133.1 +/- 66.4 ms to 100.3 +/- 34.0 ms; p less than 0.01, respectively). However, they were not affected by beta-adrenergic blocker. A-wave ratio significantly decreased after calcium-channel blockers (from 18.0 +/- 9.8% to 13.7 +/- 7.3%; p less than 0.01) and beta-adrenergic blocker (from 21.7 +/- 12.6% to 17.2 +/- 8.0%; p less than 0.01). From these observations, it is suggested tht calcium-channel blockers improved the early diastolic filling rate, whereas beta-adrenergic blocker did not affect it. It is concluded that the effects of calcium-channel blockers and beta-adrengergic blocker on early diastolic time intervals were different in patients with HCM.

Adrenergic beta-Antagonists↗

PubMed1989

Comparative effects of the opioids fentanyl and buprenorphine on ventricular vulnerability during acute coronary artery occlusion.

Fentanyl, a mu selective opioid agonist in wide clinical use, raises the ventricular fibrillation threshold in the normal canine myocardium. We have previously shown that this effect is amplified by haemorrhagic stress. In order to determine if mu receptor activation is antifibrillatory during acute myocardial ischaemia, we compared the effects of two mu selective agents, fentanyl and buprenorphine, in open chest chloralose anaesthetised dogs. Each drug was administered intravenously in two doses 1 h apart (fentanyl 30 micrograms.kg-1.dose; buprenorphine 0.3 mg.kg-1.dose). Ventricular fibrillation threshold was measured during right ventricular pacing using the single stimulus technique. The threshold was determined before and during a 10 min left anterior descending coronary artery occlusion. Prior to fentanyl administration, ventricular fibrillation threshold decreased from a control value of 19(SEM 2) mA to 12(1) mA during coronary artery occlusion. After the first dose of this drug an attenuation in the ischaemia induced fall in fibrillation threshold from 23(4) mA to 15(2) mA was observed. After the second dose of fentanyl the decline in fibrillation threshold was significantly blunted at 22(4) mA during control and 18(3) mA during occlusion, p less than 0.05 compared to no drug. In an additional series of experiments atropine sulphate abolished the antifibrillatory action of fentanyl, indicating that vagal efferent activation is responsible for the protective effect of the drug during acute myocardial ischaemia. This is in contrast with its mode of action during haemorrhage, when it enhances vagal afferent inhibition of sympathetic tone, and atropine pretreatment is without effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Anistreplase versus alteplase in acute myocardial infarction: comparative effects on left ventricular function, morbidity and 1-day coronary artery patency. The TEAM-3 Investigators.

OBJECTIVES: This double-blind, randomized, multicenter trial was designed to compare the effects of treatment with anistreplase (APSAC) and alteplase (rt-PA) on convalescent left ventricular function, morbidity and coronary artery patency at 1 day in patients with acute myocardial infarction. BACKGROUND: Anistreplase (APSAC) is a new, easily administered thrombolytic agent recently approved for treatment of acute myocardial infarction. Alteplase (rt-PA) is a rapidly acting, relatively fibrin-specific thrombolytic agent that is currently the most widely used agent in the United States. METHODS: Study entry requirements were age less than or equal to 75 years, symptom duration less than or equal to 4 h, ST segment elevation and no contraindications. The two study drugs, APSAC, 30 U/2 to 5 min, and rt-PA, 100 mg/3 h, were each given with aspirin (160 mg/day) and intravenous heparin. Prespecified end points were convalescent left ventricular function (rest/exercise), clinical morbidity and coronary artery patency at 1 day. A total of 325 patients were entered, stratified into groups with anterior (37%) or inferior or other (63%) acute myocardial infarction, randomized to receive APSAC or rt-PA and followed up for 1 month. RESULTS: At entry, patient characteristics in the two groups were balanced. Convalescent ejection fraction at the predischarge study averaged 51.3% in the APSAC group and 54.2% in the rt-PA group (p less than 0.05); at 1 month, ejection fraction averaged 50.2% versus 54.8%, respectively (p less than 0.01). In contrast, ejection fraction showed similar augmentation with exercise at 1 month after APSAC (+4.3% points) and rt-PA (+4.6% points), and exercise times were comparable. Coronary artery patency at 1 day was high and similar in both groups (APSAC 89%, rt-PA 86%). Mortality (APSAC 6.2%, rt-PA 7.9%) and the incidence of other serious clinical events, including stroke, ventricular tachycardia, ventricular fibrillation, heart failure within 1 month, recurrent ischemia and reinfarction were comparable in the two groups; and mechanical interventions were applied with equal frequency. A combined clinical morbidity index was determined and showed a comparable overall outcome for the two treatments. CONCLUSIONS: Convalescent rest ejection fraction was high after both therapies but higher after rt-PA; other clinical outcomes, including exercise function, morbidity index, and 1-day coronary artery patency, were favorable and comparable after APSAC and rt-PA.

Anistreplase↗

PubMed1975

[Renal preservation: comparative effectiveness of 2 simple perfusion technics].

The authors compare the efficacy of two perfusates, Collins' solution and Perfudex, for conservation of kidneys for short periods by perfusion and hypothermic immersion. 22 dog kidneys, removed by lombotomy, were preserved for 24 hours with one or other of these solutions and then re-implanted into their host. Radio-isotopic renography, the uptake of Hg 197 Cl3 and a hippuran renogram, used to assess the function of the transplants, suggested the functional superiority of kidneys preserved with Collins solutions. Histological controls carried out beyond the 10 th post-operative week, confirmed these results. The correlations observed between these various findings also assessed the reliability of radio-isotope examinations in the exploration of renal function.

Animals↗