Carvedilol Versus Metoprolol in Patients Undergoing Direct Percutaneous Coronary Interventions for Myocardial Infarction: Effects on QT Dynamicity

Beta-adrenergic blockers exert significant antiarrhythmic activity during ischemia and reperfusion. To further explore the beneficial effects conferred by alpha-1-adrenoceptor blockade on ventricular repolarization dynamicity in the acute phase of myocardial infarction (AMI), we compared carvedilol with metoprolol in the setting of primary percutaneous coronary intervention (PCI). In a prospective study, 100 consecutive patients undergoing primary PCI for AMI were randomized to metoprolol 200 mg/day versus carvedilol 25 mg/day. The first oral dose of study drug was administered and a 24-hour ambulatory electrocardiogram recorded upon hospital admission. Slopes of the linear QT/RR regression were determined before and after reperfusion. A total of 38 recordings of patients treated with metoprolol and 34 recordings of patients with carvedilol were eligible for analysis of QT/RR slopes. The two study groups were similar with respect to age, gender, TIMI perfusion grades, ventricular function, duration of ischemia, and site and size of infarction. Mean RR- and QT-intervals were similar to the metoprolol and carvedilol groups, before and after PCI. Likewise, there was no significant difference in QT/RR slopes between the metoprolol and carvedilol groups before PCI. In contrast, after PCI, there was a trend toward lower QT/RR slopes in the metoprolol group (from 0.18 ± 0.07 to 0.17 ± 0.08), and a significant decrease in QT/RR slopes in the carvedilol group (from 0.17 ± 0.07 to 0.14 ± 0.09). In patients undergoing successful direct PCI for AMI, treatment with carvedilol, in contrast to metoprolol, was associated with a significant decrease in QT–RR slopes, suggesting greater cardiac electrical stability.     

The Stability of bFGF Against Thermal Denaturation

Abstract— The influence of sulphated ligand and pH on thermal denaturation of basic fibroblast growth factor (bFGF) was investigated by differential scanning calorimetry (DSC), and verified by fluorescence spectrophotometry. Purity of bFGF before and after heat denaturation was assessed by SDS-PAGE analysis. In DSC studies the samples were heated to 95°C. The midpoint of the temperature change in the thermogram was designated as T_m. Sulphated ligand experiments were undertaken in potassium phosphate (pH 6·5) and sodium acetate buffers. Control thermograms (with no ligand) showed a T_m at 59°C in potassium phosphate buffer. Higher T_m values were noted as sulphated ligand concentration was increased. Similarly when heparin was added, the T_m moved to a higher temperature. A ratio as low as 0·3:1 of heparin to bFGF, increased the T_m to 90°C, which is a 31°C shift in T_m. The effect of pH on thermal denaturation of bFGF was studied in a citrate-phosphate-borate buffer system. A shift in T_m from 46 to 65°C was observed as the pH is changed from 4 to 8. Changes in protein conformation as a function of pH were monitored by fluorescence spectroscopy. It was found that a pH range from 5 to 9 is optimal for the stability of bFGF formulations. In a stability study it was noted that heparin protected bFGF from thermal denaturation only at high temperature.     

Work of friction and net work during compaction

Series of tablets were compressed in a reciprocating tablet machine with a gradually increasing die wall friction. The force needed on the upper punch to maintain the tablet dimensions constant increased with the die wall friction while the lower punch force decreased. The change in punch forces due to differences in die wall friction had no effect on the tablet strength. The net work of compaction should be constant under these circumstances. The net work calculated by subtracting the work of friction and the expansion work from the gross work input was constant when the frictional work was calculated according to one of the two equations proposed in the literature (Järvinen & Juslin 1974) while the other appears to give an overestimation of the work of friction.     

Visual Disturbances and Occipital Brain Infarct Following Acute,Transient Hypotension in Hypertensive Patients

ABSTRACT In four hypertensive patients, acute lowering of blood pressure by therapeutic or diagnostic procedures caused visual disturbances ranging from transient visual hallucinations to severe, long-lasting visual impairment. These symptoms were associated with occipital lobe cerebral infarcts that tended to occur in the border zones between the major cerebral arteries. The infarcts may be seen as the combined result of a “watershed” effect during acute hypotension and the presence of structural hypertensive vascular adaptation. When a hypertensive patient complains of visual disturbances during acute blood pressure lowering, the pressure should be allowed to settle at a level somewhat above normal.     

ITRACONAZOLE IN THE TREAMENT OF CHROMOBLASTOMYCOSIS DUE TO FONSECAEA PEDROSOI

The efficacy and tolerability of itraconazole in chromoblastomycosis due to Fonsecaea pedrosoi were evaluated in a non-comparative open clinical trial in 19 Brazilian patients with histopathologically and mycologically proven active chromoblastomycosis. Patients were classified in terms of severity and received itraconazole at the dosage of 200 to 400 mg per day until previously described criteria of cure have been reached. Clinical, mycologic, histopathologic, and laboratory evaluations were performed before, during, and after therapy. The plasma levels of itraconazole and the in vitro susceptibility of the isolates were determined in 15 cases. Clinical and biologic cure were achieved by eight patients (42%) having mild to moderate disease, after a mean duration of therapy of 7.2 months (3.2-29.6 months). Sterile scarred lesions were observed in a post-therapy follow-up lasting on average 9.6 months that was carried out in this subgroup. Clinical cure alone occurred after a mean period of 25.1 months of treatment (16-30.5 months) in seven patients (36%) with moderate to severe disease. Finally, clinical improvement was obtained in four patients (21%) with severe lesions after a mean treatment time of 17.6 months (10.7-22.5 months). All patients responded favorably to itraconazole therapy. No significant side effects nor biochemical alteration during this trial were important enough to interrupt the treatment. Our results support those of previous trials, suggesting that itraconazole is an effective compound against chromoblastomycosis due to Fonsecaea pedrosoi.