Flecainide versus quinidine in the prevention of paroxysms of atrial fibrillation

We compared the efficacy of flecainide versus quinidine in preventing paroxysms of atrial fibrillation in a randomized open crossover study. Twenty-six patients with weekly attacks of atrial fibrillation during the last 3 months, objectified by 24-h holter monitoring or 12-lead electrocardiogram (ECG) were treated for a period of 3 months with flecainide 100 mg b.i.d. or quinidine 500 mg b.i.d. Efficacy was assessed by 24-h holter monitoring and a questionnaire at the end of each month. Dosage was adjusted to flecainide 100 mg t.i.d. or quinidine 500 mg t.i.d. if patients still had symptomatic paroxysms of atrial fibrillation according to a questionnaire or on holter monitoring. In 46% of the patients, flecainide 100 mg b.i.d. caused total abolition of supraventricular tachycardia; after dose adjustment it caused 50% total abolition. For quinidine, the figures are 16% (p less than 0.05) and 32% (NS), respectively. Side effects occurred with flecainide only after dose adjustment (23%), but on quinidine they occurred before (8%) and after dose adjustment (20%). We conclude that flecainide suppresses paroxysms of atrial fibrillation significantly more often as compared with quinidine in the lower dosage regimen. Optimal treatment dosage of flecainide is 100 mg b.i.d. After quinidine dose adjustment, the difference in efficacy is no longer significant. However, side effects necessitating discontinuation of quinidine developed in 20% of the patients as compared to none in patients treated with flecainide 100 mg b.i.d.     

Risk factors for abruptio placentae

In a prospective study 90 patients who had confirmed abruption of the placenta were compared with a control group. Significantly more patients who had abruptio placentae were unmarried, smoked cigarettes, received no antenatal care, had coitus within the 48 hours preceding delivery, developed intrapartum hypertension and had a lower ponderal index than the controls. More patients with abruptio placentae had proteinuria and antepartum hypertension but statistical significance was not reached. In addition, the incidence of intra-uterine growth retardation was higher in these patients.     

Phase I study of high-dose cytosine arabinoside and etoposide in patients with advanced malignancies

Summary Cytosine arabinsodie (ara-C) and etoposide (VP-16) display synergy in the laboratory. Twenty-six patients participated in a phase I study of high-dose ara-C in combination with VP-16. The dose of VP-16 was held constant at 50 mg/m² as an intermittent infusion over 33 h; escalating doses of ara-C were given as infusions during hours 9–12 and 21–24. Myelosuppression was the dose-limiting toxicity and occurred with doses considerably less than those expected from studies of the two drugs as single agents. The suggested initial doses for phase II trials with this schedule are 750 mg/m²×2 doses of ara-C and 50 mg/m² of VP-16. Nonhematologic toxicity was minimal; therefore, further dose escalation is feasible in patients in whom myelosuppression is acceptable.Supported in part by grants from the National Cancer Institute (CA-12197 and CA-09422) and the American Cancer Society CF-85-182     

Validation of a Flow-Through Diffusion Cell for Use in Transdermal Research

A flow-through finite-dose diffusion cell has been designed for use in transdermal drug delivery research. The diffusion cell consists of an upper donor chamber and a lower receiver compartment through which a continuous supply of fresh solvent flows. The flow is directed to an automatic fraction collector. To validate the flow-through cell, its performance was compared directly against that of a conventional single-reservoir Franz cell. Homologous alkyl p-aminobenzoates were diffused through dimethylpolysiloxane membranes, and permeability coefficients increased with increasing chain length, reaching a plateau at the butyrate ester for both types of cells. This behavior suggests a shift from membrane-controlled diffusion to boundary layer control. Permeation of the butyrate and valerate compounds was significantly faster when the flow-through cell was used, suggesting that better mixing is obtained through the flow-through cell design. Considering the advantages offered in terms of time and labor saved through its use, the flow-through cell with automatic fraction collector appears to be a viable alternative to the conventional Franz cell.     

4-Aminopyridine affects synaptosomal protein phosphorylation in rat hippocampal slices

Rat brain hippocampal slices were incubated with or without the convulsant 4-aminopyridine (4-AP). From these slices a crude mitochondrial/synaptosomal membrane fraction was prepared and analyzed for endogenous protein phosphorylation. 4-AP (10(-5) M) stimulated the phosphorylation of a 50 kDa protein by 86%. The phosphorylation of this 50 kDa protein is Ca2+/calmodulin-dependent and we suggest that this protein is the lower molecular weight subunit of Ca2+/calmodulin-dependent protein kinase II (CaMK II).     

Invasive hemodynamic monitoring in children

Invasive monitoring is an important aspect of the care of the infant or child with multisystem organ dysfunction or severe acute respiratory failure. The indications for these procedures in children vary little from current recommendations for adults. The size, anatomy, physiologic responses, and pathophysiologic processes in children frequently require modifications in the placement and maintenance of these lines, and in the interpretation of the data. The literature suggests that although the absolute numbers may vary, broad therapeutic goals may be identified and treated in pediatric patients as in older patients.