A giant arachnoid cyst: Is it an innocent bystander?

Arachnoid cysts vary in their size and location. Large cysts may cause symptoms requiring surgery. It is important to assess whether patients with arachnoid cysts and neurologic symptoms can benefit from such surgical interventions.

Prestroke antiplatelet agents in first-ever ischemic stroke: clinical effects.

OBJECTIVE: To investigate whether prestroke antiplatelet agent (PA) use was associated with initial stroke severity. METHODS: This was a retrospective, case-control study based on data from a prospectively collected hospital-based stroke registry (Korea University Stroke Registry). A total of 3,025 patients who were admitted with a diagnosis of first-ever ischemic stroke within 5 days of symptom onset were included. Stroke severity was measured with the NIH Stroke Scale (NIHSS). NIHSS score ≤4 at admission was categorized as mild stroke. Patients from the PA group were matched with those from the non-PA group using estimated propensity scores at a 1:1 ratio. Stepwise multivariable logistic regression analyses were performed on patients in the matched datasets with initial mild stroke. RESULTS: Patients' mean age was 66.3 ± 13.0 years, and 1,850 were men (61.5%). A total of 748 patients had been taking antiplatelet agents prior to stroke onset; 644 patients (86.1%) were taking a single antiplatelet agent. Among these agents, aspirin (83.7%) was the most common. A total of 102 patients (13.6%) were taking 2 antiplatelet agents. Multivariable analysis after propensity score matching demonstrated that PA use was associated with initial mild stroke (odds ratio 1.344; 95% confidence interval 1.014-1.782). CONCLUSIONS: PA use was associated with decreased first-ever stroke severity, suggesting that it has a beneficial effect. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that prestroke use of antiplatelet agents reduces stroke severity in patients with first-ever acute ischemic stroke.

Utility of corrected QT interval in orthostatic intolerance.

We performed this study to determine whether electrocardiographic corrected QT (QTc) interval predicts alterations in sympathovagal balance during orthostatic intolerance (OI). We reviewed 1,368 patients presenting with symptoms suggestive of OI who underwent electrocardiography and composite autonomic function tests (AFTs). Patients with a positive response to the head-up tilt test were classified into orthostatic hypotension (OH), neurocardiogenic syncope (NCS), or postural orthostatic tachycardia syndrome (POTS) groups. A total of 275 patients (159 OH, 54 NCS, and 62 POTS) were included in the final analysis. Between-group comparisons of OI symptom grade, QTc interval, QTc dispersion, and each AFT measure were performed. QTc interval and dispersion were correlated with AFT measures. OH Patients had the most severe OI symptom grade and NCS patients the mildest. Patients with OH showed the longest QTc interval (448.8±33.6 msec), QTc dispersion (59.5±30.3 msec) and the lowest values in heart rate response to deep breathing (HRDB) (10.3±6.0 beats/min) and Valsalva ratio (1.3±0.2). Patients with POTS showed the shortest QTc interval (421.7±28.6 msec), the highest HRDB values (24.5±9.2 beats/min), Valsalva ratio (1.8±0.3), and proximal and distal leg sweat volumes in the quantitative sudomotor axon reflex test. QTc interval correlated negatively with HRDB (r = -0.443, p<0.001) and Valsalva ratio (r = -0.425, p<0.001). We found negative correlations between QTc interval and AFT values representing cardiovagal function in patients with OI. Our findings suggest that prolonged QTc interval may be considered to be a biomarker for detecting alterations in sympathovagal balance, especially cardiovagal dysfunction in OH.

Enhanced cardiomyogenic differentiation of P19 embryonal carcinoma stem cells.

BACKGROUND AND OBJECTIVES: We investigated the effects of different concentrations of serum, 5-azacytidine, and culture time on the cardiomyogenic differentiation of P19 embryonal carcinoma stem cells in the course of developing an efficient protocol for generating the cardiomyogenic lineage. MATERIALS AND METHODS: P19 cells were plated at a density of 1x10(6) cells on 10-cm bacterial dishes for 96 hours in the presence of 1% dimethyl sulfoxide to form embryoid bodies. The embryoid bodies were cultured in medium with 2% or 10% fetal bovine serum for an additional 10 or 15 consecutive days in the presence of 0, 1, or 3 microM 5-azacytidine. RESULTS: Quantitative real-time polymerase chain reaction (PCR) analysis showed that the messenger ribonucleic acid (mRNA) expression of cardiac muscle-specific genes, such as GATA4, alpha-actin, alpha-myosin heavy chain, and cardiac troponin T, were significantly higher in the 15-day culture groups than in the 10-day culture groups. Furthermore, the cardiac muscle-specific genes were expressed more in the high-serum groups compared to the low-serum groups regardless of the culture time. Cardiomyogenic differentiation of the P19 cells was most effective in 1 microM 5-azacytidine regardless of the serum concentrations. In addition, the stimulation effects of 5-azacytidine on cardiomyogenic differentiation were more significant under low-serum culture conditions compared to high-serum culture conditions. Cardiomyogenic differentiation of P19 cells was further confirmed by immunostaining with cardiac muscle-specific antibodies. CONCLUSION: Taken together, these results demonstrated that cardiomyogenic differentiation of P19 cells was enhanced by a combination of different experimental factors.