Epidemiological aspects of clinical and environmental Cryptococcus neoformans isolates in the Brazilian state Rio Grande do Sul.

Cryptococcus neoformans is a pathogenic fungus that causes life-threatening meningoencephalitis in immunocompromised patients (HIV-positive patients), and lymphoproliferative disorders in patients subjected to organ transplantation and other immunosuppressive therapies. This fungus is commonly found in soil and avian excreta, mainly from pigeon and turkey. We describe the isolation and characterization of 17 clinical and 10 environmental (pigeon excreta) isolates from the Brazilian state Rio Grande do Sul. We analyzed capsule formation, carbon assimilation pattern, canavanine-glycine-bromothymol blue (CGB) reaction, and nitrate and urease tests, as well as susceptibility to antifungal drugs. The genetic variability among C. neoformans isolates was studied using randomly amplified polymorphic DNA (RAPD) analysis. Eight of 22 arbitrary polymerase chain reaction primers used confirmed genetic polymorphism among the environmental isolates tested, suggesting that it remains feasible to use RAPD analysis as a typing method. Three of the selected primers yielded 10 molecular subclasses. The majority of the clinical isolates were assigned to the molecular subclass F. The RAPD data obtained reinforce the developing consensus about the population structure of this fungus.

[Persistence of palpitations after successful radiofrequency catheter ablation]. / Palpitações persistentes após ablação por cateter com radiofreqüência.

PURPOSE: The aim of this study was to determine prevalence and the underlying mechanism of persistent palpitations after successful radiofrequency ablation of reentrant nodal tachycardia and atrioventricular tachycardia. METHODS: One hundred twenty consecutive patients (mean age of 36 +/- 16 years) who underwent radiofrequency catheter ablation of atrioventricular or reentrant nodal tachycardia constituted the analyzed group. Prevalence of palpitations was investigated during out-clinic visits and telephone interviews. Patients complaining of palpitations were divided in 2 groups: 1) those in whom palpitations lasted more than 30 seconds, and 2) those in whom the paroxysms lasted < 30 seconds (group II). All patients underwent clinical evaluation, ECG and Holter monitoring. Transesophageal atrial pacing and electrophysiologic stimulation were carried out when judged necessary. RESULTS: During a follow up period of 9 +/- 4 months, 52 patients complained of palpitations. In 31 group I patients, palpitations were related to ventricular and atrial premature beats as shown during Holter monitoring. In group II patients, eight had recurrence, five presented a new arrhythmia not recognized previously to the ablative procedure and two patients had their symptoms related to arrhythmias recognized before ablation but taken as asymptomatic. The mechanism of palpitations was not identified in six patients. CONCLUSION: Palpitations may persist in 43% of patients who undergo radiofrequency ablation to treat reentrant nodal tachycardia and atrioventricular tachycardia. Recurrence and treatment are more likely when palpitations last longer than 30 seconds.