PubMed Health⌕ Search

Biomedical subjects

E V Capparelli

Publications and source records attributed to E V Capparelli.

34 records · Page 2Linked to original sources
PubMed1994

A masked prospective evaluation of outcome parameters for cytomegalovirus-related retinal detachment surgery in patients with acquired immune deficiency syndrome.

PURPOSE: The management of cytomegalovirus (CMV)-related rhegmatogenous retinal detachments in patients with acquired immune deficiency syndrome (AIDS) has been the subject of recent attention and controversy because of the high degree of variability in visual outcome, as well as significant differences in the reported incidence of profound postoperative optic atrophy. This study was designed to evaluate the various parameters affecting postoperative visual outcome, and to quantitate the degree of postoperative optic disc pallor. METHODS: The results of 65 consecutive surgeries for CMV-related retinal detachments in 51 patients with AIDS were prospectively studied. Postoperative vision, survival, optic disc pallor, and retinitis extent were analyzed. Serial photographs of optic discs underwent masked evaluation. RESULTS: Mean postoperative survival was 30 weeks (range, 2-146 weeks). Mean best postoperative visual acuity was 20/66 (range, 20/20-2/200) and mean final postoperative visual acuity was 20/100 (range, 20/25-no light perception). Analysis of visual outcome for eyes with no macular or papillo-macular retinitis showed a best postoperative visual acuity of 20/60 (range, 20/25-2/200) and mean final postoperative visual acuity of 20/80 (range, 20/25-no light perception). Postoperative vision was not affected by the presence of a preoperative macular detachment, with both groups (macula on or off detachments), achieving a best postoperative visual acuity of 20/60 in the absence of macular retinitis. Mild postoperative optic disc pallor was observed in 30% of surgical eyes at the final postoperative visit, and moderate pallor was noted in 13%. The mean degree of optic disc pallor was not different from the degree of optic disc pallor seen in fellow, nonsurgical eyes with CMV retinitis (surgical versus fellow nonsurgical eyes, 29% +/- 23% versus 26% +/- 30%; P = 0.64). CONCLUSION: In this largest reported series of reattachment surgery for CMV-related retinal detachments, patients are experiencing increased postoperative survival, good vision, and relative optic nerve health.

AIDS-Related Opportunistic Infections↗
PubMed1994

Pharmacokinetic considerations in the adolescent: non-cytochrome P450 metabolic pathways.

The non-oxidative metabolic reactions of methylation, acetylation, sulfation, glucuronidation, conjugation with amino acids (primarily with glycine), glutathione conjugation and esterase hydrolysis function to detoxify and enhance the elimination of drugs and pro-drugs, many of them as phase II reactions subsequent to oxidation. While the influence of maturation has been recognized in the development of hepatic oxidative capacity and specific pathways studied, considerably less attention has focused on the maturational effect in non-oxidative metabolism despite its role in drug deactivation, detoxification, and elimination. Consequently phase II metabolic capacities during adolescence remain primarily speculative. Conflicting data about one of these pathways, glucuronidation, suggest unexplored puberty- or gender-related phenomena influencing function in this system.

Acetylation↗
PubMed1993

Pathophysiology and treatment of clinically resistant cytomegalovirus retinitis.

PURPOSE: To determine the incidence, pathophysiology, clinical outcome, and survival in patients with clinically resistant retinitis. METHODS: Cytomegalovirus (CMV) retinitis was prospectively studied in 100 patients with acquired immune deficiency syndrome (AIDS). In 11 of these patients, clinically resistant retinitis developed, defined as new activity or progression, despite at least 8 consecutive weeks of induction doses of either foscarnet or ganciclovir. Fundus photography, pharmacokinetics, CMV cultures and sensitivities, and survival analyses were studied. The therapeutic interventions attempted after clinically resistant retinitis was identified included continuing a high dose (induction level) of the same antiviral drug, changing the antiviral drug, and combining antiviral therapy with foscarnet and ganciclovir. RESULTS: Clinically resistant retinitis occurred in 11 (11%) of 100 patients with CMV retinitis and appeared to be a manifestation of acquired CMV antiviral drug resistance. Drug metabolism and pharmacokinetics in these patients were normal. The use of combination therapy with foscarnet and ganciclovir was effective in halting the progression of retinitis in three (75%) of four patients (6 of 7 eyes able to be evaluated) receiving combination therapy. CONCLUSION: Clinically resistant retinitis is a manifestation of infection by CMV that has acquired drug resistance. In these patients, combination antiviral drug treatment should be considered. It is likely that clinically resistant retinitis will become more frequent as patients with CMV retinitis and AIDS survive longer.

AIDS-Related Opportunistic Infections↗
PubMed1993

Intravitreal ganciclovir concentration after intravenous administration in AIDS patients with cytomegalovirus retinitis: implications for therapy.

To determine whether therapeutic intravitreal concentrations of ganciclovir are achieved after intravenous administration, vitreous samples were obtained intraoperatively from 23 eyes of 22 AIDS patients with retinal detachments associated with cytomegalovirus (CMV) retinitis. The mean intravitreal ganciclovir concentration of all samples was 0.93 +/- 0.39 microgram/mL (3.6 +/- 1.5 microM). This level is near the published trough serum concentrations obtained with every-12-h intravenous dosing and well below the peak. It is significantly below the concentration of ganciclovir required to achieve 50% of viral plaque formation for many human CMV strains. Only a small decrease in vitreous drug levels was observed as a function of time after last dose. Intravenous administration of ganciclovir results in near-steady-state subtherapeutic intravitreal ganciclovir concentrations for many CMV isolates. This may explain the difficulty of long-term complete suppression of CMV retinitis.

AIDS-Related Opportunistic Infections↗
PubMed1992

Adjuvant metoprolol improves efficacy of class I antiarrhythmic drugs in patients with inducible sustained monomorphic ventricular tachycardia.

Inducible ventricular tachycardia frequently persists despite solitary class I antiarrhythmic drug therapy. To determine the effect of metoprolol as adjuvant therapy, 19 patients with clinical ventricular tachycardia with baseline inducible sustained monomorphic ventricular tachycardia and persistently inducible ventricular tachycardia despite class I drugs were evaluated. Eight of 19 patients (42%) became noninducible when metoprolol was added to class I drug therapy. Sixteen of 19 patients (84%) were harder to induce or noninducible on a regimen of adjuvant metoprolol therapy. In evaluating the clinical characteristics of the 19 patients, no significant differences were found between patients who were persistently inducible and those rendered noninducible. In evaluating the electrophysiologic characteristics, the group eventually rendered noninducible had a significantly shorter baseline induced cycle length (259 +/- 27 vs 305 +/- 53 msec). Combination class I drug and metoprolol therapy significantly lengthened the ventricular effective refractory period in both groups compared with baseline. The long-term follow-up was excellent in all patients remaining on metoprolol in the noninducible group. Therefore adjuvant metoprolol therapy creates a significant improvement in a number of patients with persistently inducible ventricular tachycardia despite class I drug therapy.

Adult↗
PubMed1992

Diltiazem improves resuscitation from experimental ventricular fibrillation in dogs.

OBJECTIVE: To determine the effect of diltiazem on survival immediately after cardiac arrest and cardiopulmonary resuscitation (CPR) in dogs. DESIGN: Prospective, double-blind, randomized trial. SETTING: Laboratory at a large, university-affiliated medical center. SUBJECTS: Twenty-eight mongrel dogs, weighing 12 to 16 kg. INTERVENTIONS: After the administration of anesthesia, catheters were placed in the pulmonary artery, aortic arch, left ventricle, right ventricle, and great cardiac vein (12 dogs) for sample collection, pressure determinations, and induction of ventricular fibrillation. Dogs were randomized to receive either diltiazem, calcium chloride, or placebo (saline) either before or early during CPR. Dogs underwent 3 mins of unassisted fibrillatory arrest followed by 10 mins of standard CPR using a pneumatic device. After 13 mins of ventricular fibrillation, defibrillation was attempted repeatedly for less than or equal to 10 mins. Successful resuscitation was defined as an organized rhythm with an unassisted systolic BP of greater than 60 mm Hg for greater than or equal to 2 mins. MEASUREMENTS AND MAIN RESULTS: The resuscitation rate was significantly greater in diltiazem-treated animals (100%) than in those dogs receiving calcium (57%) or placebo (29%). Diltiazem-treated animals were resuscitated faster and required fewer defibrillation attempts than did dogs in the other groups. During CPR, coronary artery perfusion pressure and blood gases (arterial, venous, and myocardial) were similar among treatment groups. CONCLUSIONS: Diltiazem improves the resuscitation from experimentally induced ventricular fibrillation when administered before or early during CPR. This response may have important clinical implications in the treatment of patients undergoing cardiac arrest and CPR.

Analysis of Variance↗
PubMed1991

The effect of CPR on plasma diltiazem concentrations in dogs.

STUDY OBJECTIVE: To determine the effect of cardiac arrest with CPR on diltiazem concentrations in dogs. DESIGN: Prospective, double-blind, randomized trial. SETTING: Laboratory at a large university-affiliated medical center. TYPE OF PARTICIPANTS: Twenty mongrel dogs. INTERVENTIONS: Following administration of anesthesia, catheters were placed in the pulmonary artery, aortic arch, left ventricle, and right ventricle. Dogs were randomized to receive diltiazem (0.5 mg/kg) either 60 minutes before or during cardiac arrest with CPR. After 13 minutes of cardiac arrest, defibrillation was attempted. MEASUREMENTS AND MAIN RESULTS: Frequent blood samples for diltiazem concentrations were obtained before, during, and after cardiac arrest. The mean diltiazem concentration rose 70% during CPR in the group that received diltiazem before cardiac arrest. The group that received diltiazem during CPR had concentrations five times greater than expected during sinus rhythm. CONCLUSION: Increased diltiazem concentrations are observed during CPR and are probably related to altered distribution encountered during CPR.

Animals↗
PubMed1989

Factors determining maintenance of sinus rhythm after chronic atrial fibrillation with left atrial dilatation.

Successful therapy of atrial fibrillation (AF) has been reportedly influenced by a variety of factors including patient age, type of underlying heart disease, duration of arrhythmia, left ventricular function and left atrial (LA) size. To determine which of these factors are associated with maintenance of sinus rhythm after conversion, 43 patients with symptomatic chronic AF in the setting of a dilated left atrium (greater than or equal to 45 mm, range 45 to 78) were followed for at least 6 months after the return of sinus rhythm. Class IA drugs, IC drugs or amiodarone were used for therapy. Life table analysis showed sinus rhythm to be maintained in 81% for 6 months, 79% for 12 months and 60% for 24 months. Factors positively associated with success were conversion with drug therapy alone, duration of chronic AF less than or equal to 1 year, absence of mitral valve disease and LA dimension less than or equal to 60 mm (all p less than 0.05). Patient age, left ventricular function and presence of coronary disease were not associated with outcome. Thus, patients with moderate LA dilatation (45 to 60 mm) and a short duration of chronic AF can often be maintained in sinus rhythm, especially if they convert with pharmacologic intervention alone.

Aged↗
PubMed1989

Antiarrhythmic efficacy of solitary beta-adrenergic blockade for patients with sustained ventricular tachyarrhythmias.

To assess the efficacy and predictability of solitary beta-adrenergic blocker (BB) therapy for ventricular tachyarrhythmia (VT), 30 patients (16 men and 14 women) with a mean age of 55 years, who initially had sustained ventricular tachycardia (70%) or ventricular fibrillation (30%), were studied. Results of baseline arrhythmia tests showed VT on ECG monitoring in 57% of the patients, during exercise in 50%, induced by programmed stimulation in 69%, increasing to 86% during isoproterenol. BB therapy prevented inducible VT during programmed stimulation in 37% of the patients, prevented VT on ECG monitoring in 54%, and prevented VT during exercise in 83%. Long-term BB therapy was given to 24 of 30 patients, whereas six other patients with hemodynamically unstable VT during BB therapy received other long-term treatment. During a mean follow-up of 824 days, 6 of 24 patients had recurrent VT. BB therapy was discontinued in two patients because of side effects. Long-term success was predicted by left ventricular ejection fraction greater than 45%, absence of coronary disease, and age less than 60 years (all p less than 0.02). Neither suppression of arrhythmia during exercise testing, nor results of programmed stimulation or ECG monitoring were predictive of outcome. Thus beta-adrenergic blockers can be effective as solitary antiarrhythmic therapy in selected patients with VT.

Adrenergic beta-Antagonists↗
PubMed1989

Differences in systemic and myocardial blood acid-base status during cardiopulmonary resuscitation.

Simultaneous arterial (aortic), mixed venous (pulmonary artery), and myocardial venous (great cardiac vein) blood gas and lactate concentrations were obtained in 12 dogs before and during cardiac arrest and CPR. We observed marked mixed venous and myocardial venous acidosis and increased PaCO2 but normal pHa and reduced PaCO2. Furthermore, the pH was significantly lower and the PCO2 significantly higher at the myocardial venous site compared to the mixed venous site, and marked myocardial lactate production occurred during CPR. Calculated bicarbonate and CO2 content (CCO2) did not increase during CPR from any site compared to control values and actually decreased significantly in arterial and myocardial venous samples. Changes in hydrogen ion concentration in both mixed venous and myocardial venous blood correlated with changes in lactate concentration but not total CCO2. Our results during CPR demonstrate a) a significant discrepancy between arterial and mixed venous blood gases but also a large and significant discrepancy between mixed venous and myocardial venous blood gases, b) significant anaerobic systemic and myocardial metabolism, and c) that mixed venous and myocardial venous acidosis is possibly a result of lactic acidosis.

Acid-Base Equilibrium↗
PubMed1988

Clinical and electrophysiologic effects of flecainide in patients with refractory ventricular tachycardia.

The electrophysiologic effects and antiarrhythmic efficacy of flecainide were evaluated by electrophysiologic study (EPS) in 20 patients with ventricular tachycardia (VT) refractory to an average 2.9 drugs. In 19 patients EPSs were performed with patients not receiving antiarrhythmic medications and receiving oral flecainide therapy at steady state (mean dose, 235 +/- 67 mg/day). Flecainide significantly increased the QRS complex duration (27%, P less than .001), PR interval (17%, P less than .001), and right ventricular effective refractory periods 8.5% and 21.1% (P less than .01) for the first and second extrastimuli, respectively. During baseline EPS, 17 patients were induced into VT and two were noninducible. Flecainide prevented EPS-induced VT in five patients and the induced VT became slow and hemodynamically stable in three. Two patients who failed flecainide monotherapy were induced into slow hemodynamically stable VT with flecainide in combination with amiodarone. The two noninducible patients, during baseline EPS, had suppression of spontaneous VT with flecainide. Overall, 13 of 20 patients received flecainide either alone or in combination with amiodarone for chronic therapy. Side effects encountered during the study consisted of blurred vision, dizziness, weakness, lethargy, nausea, worsened heart failure and bradyarrhythmias. After a mean 9-month follow-up (3 to 16 months) nine patients remain on flecainide therapy. There were three recurrences of slow, hemodynamically stable VT and no episodes of sudden death. Low-dose flecainide, either alone or in combination with other agents, is effective therapy for certain patients with refractory VT but heart failure remains a significant concern in patients with depressed left ventricular function.

Aged↗
PubMed1988

Clinical pharmacokinetics of controlled-release disopyramide in patients with cardiac arrhythmias.

UNLABELLED: The pharmacokinetics of the controlled-release preparation of disopyramide phosphate (Norpace CR, Searle Laboratories, Chicago, IL) were studied in ten patients with cardiac arrhythmias. Multiple-serum disopyramide concentrations were obtained after a 300-mg oral dose. Each patient then received chronic oral therapy with the controlled-release preparation (400 to 1000 mg/day) on an every-12-hour schedule. At steady state, disopyramide trough concentrations were obtained. Serum disopyramide concentrations were determined by high performance liquid chromatography. The regimen was well tolerated by all patients. The mean (+/- SD) time to maximum concentration, maximum concentration, and concentrations 11 and 24 hours after the initial dose were 5.5 +/- 1.3 hours and 2.8 +/- 0.8, 2.0 +/- 0.9, and 1.2 +/- 0.5 micrograms/mL, respectively. A low Cmax to trough concentration ratio of 1.35 +/- 0.26 was observed after the initial dose. Linear regression analysis of the serum disopyramide concentrations 11 hours after initial dose (trough) versus trough concentrations at steady state (dose adjusted) showed a strong correlation (r = 0.87, intercept = 0.03, and slope = 1.9). Regression analysis also showed a strong relationship between the area under the curve (AUC) from time 0 to 11 hours after the initial dose and the trough at steady state (r = 0.86). CONCLUSIONS: The controlled-release preparation of disopyramide, when administered every 12 hours in patients with cardiac arrhythmias, should produce low peaks to trough fluctuations. Because disopyramide concentrations after the initial dose correlate well with trough concentrations at steady state, these concentrations may provide a simple and convenient method for prospective monitoring of disopyramide therapy in patients receiving the controlled-release preparation.

Adult↗
PubMed1988

Rimantadine pharmacokinetics in healthy subjects and patients with end-stage renal failure.

The single-dose (two 100 mg doses) pharmacokinetics of rimantadine hydrochloride were compared in eight patients with end-stage renal disease who were on hemodialysis and seven age-matched healthy subjects. Plasma and urine rimantadine concentrations were determined by a GC/MS method. The plasma half-life (43.6 vs 27.5 hours) and AUC (9.9 +/- 2.1 vs 6.0 +/- 1.6 micrograms.hr/ml) were significantly (p less than 0.05) increased in the patient population. No significant differences were noted in the maximum rimantadine concentration, time of maximum concentration, or apparent volume of distribution. Urinary excretion of unchanged rimantadine accounted for 16% of the dose in the healthy subjects. Hemodialysis did not appreciably remove rimantadine. These findings suggest that rimantadine dosage may need to be reduced in patients with end-stage renal disease but supplemental doses on dialysis days are not required.

Adamantane↗
PubMedDate not supplied

Direct comparison of three methods for predicting digoxin concentrations.

Three methods of determining digoxin population pharmacokinetic parameters were compared for their abilities to predict 118 measured serum digoxin concentrations (SDCs) in 49 patients. NONMEM software (version IV) was used to generate a residual and a weighted residual for each measured-concentration-predicted-concentration pair. Prediction error analysis was done by a maximum likelihood technique that accounted for several within-patient measures. Data analysis also included graphic observation of weighted residuals (WRES) and calculation of the mean WRES and median absolute prediction error. A further parallel analysis was also carried out on subpopulations with and without concurrent quinidine and congestive heart failure (CHF). Method III was without bias in all subpopulations studied and had the smallest WRES in all populations. Method I was without bias in the overall population, however, it underpredicted SDCs in patients receiving quinidine and in those with CHF. Method II underpredicted SDCs in the overall population, those receiving quinidine, and in patients without CHF. There were no between-method differences in precision as assessed by absolute prediction error.

Adult↗