The effects of pacing-induced changes in cycle length on the refractory periods of the atrium, A-V node and His-Purkinje system were studied in 24 patients using the extra stimulus technique. Refractory period determinations were made at two or more cycle lengths in all patients. Slopes relating cycle length and refractory periods were calculated using the least squares method. Both the effecti...

Among patients with resistant hypertension (RHTN), there are those whose blood pressure (BP) remains uncontrolled in spite of maximal medical therapy. This retrospective analysis aims to characterize these patients with refractory hypertension. Refractory hypertension was defined as BP that remained uncontrolled after ≥3 visits to a hypertension clinic within a minimum 6-month follow-up period....

OBJECTIVES Refractory periodontitis is the occurrence of additional clinical attachment loss after repeated attempts to control the infection with conventional periodontal therapy. Some microorganisms seem to be involved in the pathogenesis of chronic refractory periodontitis. The prevalence of Enterococcus faecalis in the oral cavity seems to be higher in individuals with periodontitis. Theref...

Another question of interest concerns the behaviour of a learning algorithm in the infinite sample limit: as it receives more and more data, does the algorithm converge to an optimal prediction rule, i.e. does the generalization error of the learned function approach the optimal error? Recall that for a distribution D on X × Y and a loss ` : Y × Y→[0,∞), the optimal error w.r.t. D and ` is the ...

Background The X-linked cyclin-dependent kinase like 5 (CDKL5/STK9) gene has been shown to be responsible for a severe encephalopathy condition characterized by early onset of epilepsy and severe developmental delay. CDKL5 mutations have been shown to be more frequent among female patients. Results Here we report a 6- month male patient, second child of a healthy non consanguineous in the Irani...

Steroid-refractory graft-versus-host disease is a life-threatening complication after allogeneic stem cell transplantation. Evidence is accumulating that steroid-refractory graft-versus-host disease is associated with endothelial distress. Endothelial cell homeostasis is regulated by nitric oxide, and serum nitrates are derived from nitric oxide synthase activity or dietary sources. In this ret...

Intravitreal anti-vascular endothelial growth factor (VEGF) agents can treat macular edema (ME) in branch retinal vein occlusion (BRVO). However, refractory ME, the mechanism of which is not well elucidated, occurs frequently. Sixty-six eyes with ME secondary to BRVO were enrolled in this retrospective observational case-control study. Twenty eyes received a sub-Tenon's capsule injection of tri...

Abst rac t Objective: Approximately 30% of treatment-resistant schizophrenic patients do not fully respond to Clozapine and such patients are termed Clozapine non-responders or super-refractory schizophrenics. The aim of this study was to characterize patients with super-refractory schizophrenia according to demographic and psychopathological variables, as compared with patients with refractory...