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Biomedical subjects

V Andrews

Publications and source records attributed to V Andrews.

33 records · Page 2Linked to original sources
PubMed1987

The significance of pancytopenia in miliary tuberculosis.

Patients with miliary tuberculosis accompanied by a pancytopenia rarely survive their disease. If the peripheral blood picture does recover it has been taken as an indication that there is no underlying haematological disease, and so re-examination of the bone marrow is not performed. A case is described where resolution of the pancytopenia occurred but a persisting haematological disease remained. Aspects of haematological disease associated with tuberculosis are discussed.

Aged↗
PubMed1987

Pharmacokinetics and hemodynamics of amrinone in patients with chronic cardiac failure of diverse etiology.

The pharmacokinetics of amrinone and its relationship to ventricular function were assessed in 15 patients with chronic cardiac failure following the administration of a single 100 mg oral dose. Patients examined had Class II (1 patient), Class III (13 patients) and Class IV (1 patient) heart failure as characterized by the New York Heart Association classification. Blood samples were obtained following amrinone administration at selected times for 8 hours following the dose. Cardiac output was assessed serially for 5 hours following amrinone dosing. Mean (SD) peak plasma concentrations of amrinone (2.1 (1.1) mcg/ml) were obtained 0.5 to 2 hours after drug administration. The mean (SD) apparent oral clearance, apparent volume of distribution at steady state and half-life of amrinone were 0.23 (0.13) L/hr/kg, 1.2 (0.4) L/kg, and 4.8 (3.0) hr. Peak increases in cardiac index averaged 50% of baseline values and improvement was maintained at least 5 hours following amrinone dosing when compared to baseline cardiac index (p less than 0.05). Examination of the relationship between cardiac index corrected for baseline and amrinone plasma concentrations within individuals yielded strong and highly significant relationships (r greater than 0.90; p less than 0.025) in five patients, while in the remaining patients, either no relationship existed or insufficient data was available for analysis. When the data from all patients were pooled, a modest though significant relationship (r = 0.67; p less than 0.01) existed between cardiac index corrected for baseline and the post-absorptive, post-distributive amrinone plasma concentration. No difference in response to amrinone as a function of failure etiology or functional aerobic capacity was evident. Evaluation of the relationships between the mean improvement in cardiac index versus amrinone plasma concentration, as well as the time courses of these parameters indicate that the site of action of amrinone may be pharmacokinetically distinguishable from plasma and the tissues in instantaneous equilibrium with plasma.

Acetylation↗
PubMed1986

Is topical haloperidol a useful glaucoma treatment?

A randomised, double blind, single dose study of topical haloperidol, a dopamine receptor blocking drug, was performed on 20 healthy volunteers. After its administration a modest reduction in intraocular pressure was recorded over the six-hour study period, but the difference was not significant at the p less than 0.05 level. Although dopamine blocking agents are effective in reducing intraocular pressure in experimental animals, topical haloperidol appears unlikely to be clinically useful in the treatment of glaucoma.

Administration, Topical↗
PubMed1985

Milrinone in the treatment of chronic cardiac failure: a controlled trial.

This study examines the acute hemodynamic response to intravenous and oral milrinone in 12 patients with moderate to moderately severe heart failure. The patients received milrinone or placebo at random in an 8-week double-blind trial. Dosing level and schedule were determined by the hemodynamic results. Acute and chronic plasma samples for milrinone concentration were drawn from patients throughout the study. Milrinone was administered intravenously in successive doses of 25, 50, and 75 micrograms/kg. This resulted in a 16.5%, 12.5%, and 28.4% peak increase in cardiac index, with a concomitant 24%, 29%, and 38% decrease in pulmonary capillary wedge pressure. There were no significant relationships between any of the mean maximal hemodynamic values and milrinone plasma concentration. Six patients received milrinone and six patients received placebo; only five patients completed the blinded phase. There was no significant difference between the groups in exercise capacity, but the conditions of five of the six patients who received placebo deteriorated. In two of the patients who received milrinone the aerobic capacity improved greater than 2 cc/min/kg over baseline, and an additional two patients reported a marked subjective improvement. The results of this study indicate that oral milrinone in the management of patients with chronic cardiac failure would justify larger controlled studies.

Administration, Oral↗
PubMed1985

Effect of ascorbic acid on plasma calcium in guinea pigs.

Ascorbic acid (246 mg/kg body weight/day) was administered orally to 9-week old female guinea pigs of the Hartley strain over a period of 20 months. The controls received 40 mg/kg body weight/day of ascorbic acid in the diet. Observations were made on body weight, food and water consumption, plasma ascorbic acid, and the total calcium and ionic calcium levels at various times during the growth of these animals. A second experiment was carried out when the guinea pigs were 18 months old. In addition to the oral intake, they received intraperitoneally 623 mg/kg body weight/day of sodium ascorbate for 6 weeks. With this treatment, the ascorbic acid intake for the test animals was 20 times that for the controls. The plasma ascorbic acid and calcium levels of these animals were measured during the treatment. In the ascorbic acid-treated animals, there was a significant elevation in plasma ascorbic acid level in comparison with the controls, but no substantial differences were observed in the body weight, total calcium or ionic calcium levels in the plasma. The results suggest that the administration of large quantities of ascorbic acid does not affect total calcium or ionic calcium levels in the plasma of these animals.

Animals↗
PubMed1984

Amrinone in the treatment of chronic cardiac failure.

The efficacy and safety of oral amrinone were examined in 17 patients with moderately severe to severe heart failure that was refractory to standard medical therapy and vasodilators. The short-term and 28 week response to open amrinone therapy was assessed first, followed by a placebo-controlled, double-blind withdrawal study of two 13 week stages in nine patients. Rest and exercise ventricular function were determined before and after 32 hours of amrinone; aerobic capacity was serially assessed. After 2 hours, 1.64 mg/kg amrinone produced a 40% (p less than 0.001) increase in cardiac output and a 32% (p less than 0.02) decrease in pulmonary wedge pressure without altering heart rate or blood pressure. The exercise cardiac index-wedge pressure curve obtained 32 hours after the first oral dose was significantly shifted (p less than 0.05) above control values. A sustained improvement in maximal oxygen uptake was noted during long-term open amrinone therapy. Subsequently, seven of the patients randomized to placebo therapy had a significant deterioration of symptoms or exercise tolerance, or both. After 4 weeks of readministration of amrinone, clinical stability was once again established and exercise tolerance was improved by Weeks 8 to 16. Adverse effects of thrombocytopenia (one patient) and hepatic dysfunction (one patient) attributable to amrinone were observed. It is concluded that amrinone is effective in the long-term treatment of chronic cardiac failure.

Aged↗
PubMed1982

Cardiotonic agents in the management of chronic cardiac failure.

Heart failure is a syndrome with distinct clinical signs and symptoms. The severity of cardiac failure and a deterioration in functional capacity can be determined by a progressive exercise test and by the noninvasive determination of maximum oxygen uptake. In patients with severe cardiac failure refractory to medica therapy, particularly those with cardiomyopathy or ischemic heart disease, survival is seriously compromised, resembling the most serious malignancy. Cardiotonic agents may be useful in improving the quality of life, provided that they are effective and are given sufficiently early in the course of the disease. Dobutamine given intravenously augments cardiac performance and improves renal function in patients with very advanced disease refractory to multiple diuretics; long-term survival, however, remains dismal. Amrinone appears to be a promising agent for the long-term treatment of chronic cardiac failure; the utility of pirbuterol, an oral catecholamine analog, remains to be determined.

Adult↗
PubMed1982

Pirbuterol, an oral beta-adrenergic receptor agonist, in the treatment of chronic cardiac failure.

Pirbuterol (PB), an oral beta-adrenergic-receptor agonist, has the pharmacologic effects of vasodilation and positive inotropy. The present studies were undertaken to determine the value of PB in the long-term therapy of chronic cardiac failure. A double-blind, randomized, 7-week trial comparing PB (20 mg three times daily) with placebo in 12 patients was followed by 12 weeks of open PB therapy. Dose-dependent nervousness and tremulousness limited the unit PB dose to less than 20 mg in six patients. In all patients, clinical status, exercise tolerance and maximal oxygen uptake, left ventricular echocardiographic dimension and cardiothoracic ratio were unchanged from control after 7 weeks of placebo or PB or after 12--19 weeks of PB. To assess the adequacy of 20 mg of PB, the dose-response relations of cardiocirculatory effects to 10, 15, 20 and 30 mg of PB were compared in seven of the above patients and nine other patients. Cardiac output was significantly elevated and wedge pressure reduced after all four doses, but these changes were sustained from 6 hours after 20- and 30-mg doses only. Thus, the role of PB in the management of chronic cardiac failure appears limited; judgment of its utility must await the results of additional controlled trials.

Adrenergic beta-Agonists↗
PubMed1981

Vasodilator and inotropic agents in treatment of chronic cardiac failure: clinical experience and response in exercise performance.

The sensations of breathlessness and fatigue limit the capacity of patients with chronic congestive cardiac failure (CHF) to participate in physical activities. As a result, patients with CHF gauge quality of life in terms of symptom-free activities they can undertake. Physicians attempt to alleviate these limiting symptoms and increase the exercise capacity of patients with CHF by therapeutic interventions. In recent years a variety of systemic vasodilators and inotropic agents have been introduced to aid digitalis and diuretics in improving cardiac performance in patients with CHF. Although the pumping function of the heart is enhanced at rest, it remains to be determined whether exercise tolerance is also improved. In this paper we review our clinical experience with a number of systemic vasodilators and positive inotropic agents, focusing particular attention on their influence on exercise performance in patients with CHF. This experience includes (1) 28-week double-blind study of hydralazine vs placebo in 19 patients with CHF, (2) 52-week double-blind crossover study of trimazosin (alpha 1 blockade) vs placebo in 27 patients with CHF of varying severity, and (3) open study of amrinone (positive inotropic agent) in 12 patients with CHF.

Aerobiosis↗
PubMed1979

Increase in leg blood-flow by normovolaemic haemodilution in intermittent claudication.

Normovolaemic haemodilution down to a packed-cell volume of 35% was done in 10 patients with stable intermittent claudication. For a mean reducation in the packed-cell volume of 21.5% there was a 170% increase in peak calf blood-flow and a 111% increase in haemoglobin delivery. 7 of the 10 patients reported an increased walking distance. Normovolaemic haemodilution may be of use in the management of some patients with peripheral vascular disease.

Aged↗
PubMedDate not supplied

On the standard error of the probability of a particular diagnosis.

Approximate standard errors of the probability of a particular diagnosis are given for the predictive and estimative methods described by Aitchison and Dunsmore. An example used in the detection of carriers of Duchenne muscular dystrophy (DMD) is given for illustration.

Diagnosis↗