The HCV Core Protein Acts as a Positive Regulator of Fas-Mediated Apoptosis in a Human Lymphoblastoid T Cell Line

AbstractHepatitis C virus (HCV) is a major human pathogen causing mild to severe liver disease worldwide and is remarkably efficient at establishing persistent infections. Previously, we have shown that the core protein has an immunomodulatory function including the suppression of T lymphocyte responses to viral infection. To investigate the underlying mechanism for the role of core protein in immune modulation, we examined the effect of core on the sensitivity of the human T cell line, Jurkat, to Fas-mediated apoptosis. The transient and stable expression of core protein in Jurkat cells increased the sensitivity of cells to Fas-mediated apoptosis when compared to control cells expressing vector DNA alone. In addition, we demonstrated that the core protein binds to the cytoplasmic domain of Fas which may enhance the downstream signaling event of Fas-mediated apoptosis. The expression of core protein did not alter the cell surface expression of Fas, indicating that the increased sensitivity of core-expressing cells to Fas ligand was not due to upregulation of Fas. Furthermore, we observed the augmentation of caspase-3 activity in core-expressing cells. These results suggest that the core protein may promote the apoptosis of immune cells during HCV infection via the Fas signaling pathway, thus facilitating HCV persistence

Reduced systemic vascular resistance is the underlying hemodynamic mechanism in nitrate-stimulated vasovagal syncope during head-up tilt-table test

AbstractBackgroundNitroglycerin (NTG) challenge during head-up tilt-table testing (HUTT) is often utilized to determine the etiology of unexplained vascular syncope. However, conflicting results concerning nitrate-induced hemodynamic changes during HUTT have been reported. The purpose of this study was to assess the determinants of presyncopal symptoms during NTG-stimulated HUTT.MethodsWe evaluated 40 patients with suspected vasovagal syncope. Beat-to-beat changes in blood pressure, heart rate (HR), cardiac index (CI), and systemic vascular resistance (SVR) during HUTT were measured with thoracic impedance cardiography and a plethysmographic finger arterial pressure monitoring device.ResultsNone of the 40 patients complained of presyncopal symptoms during passive HUTT. However, after the administration of NTG 28 patients showed presyncopal symptoms (NTG+ group) and the remaining 12 patients did not (NTG– group). HR, CI, and the stroke index did not significantly differ between the two groups, whereas mean arterial pressure and SVR were significantly lower in the NTG+ group.ConclusionsPresyncopal symptoms during NTG-stimulated HUTT are SVR mediated, not cardiac output mediated. This study challenges the conventional idea of a decrease in cardiac output mediated by NTG as the overriding cause of presyncopal symptoms during HUTT

Abdominal pain without bruising or sign of trauma: pancreatic injuries in children is difficult to predict

Pancreatic injuries due to trauma in children are rare. An early diagnosis is difficult as the signs and symptoms are insidious, but delays in diagnosis can lead to significant complications. We report a case of a child who visited the emergency department with aggravating abdominal pain. The physicians first diagnosed the abdominal pain as being caused by a disease in the emergency department, but the patient was subsequently diagnosed with pancreatic injury. Clinicians should be aware of a possible trauma in children who complain of vague abdominal pain even in the absence of corresponding history

Methods and performance of a three-dimensional whole-core transport code DeCART

DeCART is a three-dimensional whole-core transport code capable of performing direct core calculations at power generating conditions without involving a priori homogenized few-group constant generation. In this paper, the methods of DeCART, which are characterized by the planar method of characteristics (MOC) solutions, the cell based coarse mesh finite difference (CMFD) formulation, the subgroup method for resonance treatment and subpin level thermal feedback, are presented as a whole. The performance of the code in the aspect of solution accuracy and computing speed is then examined using the applications to the C5G7MOX benchmark and its modified rodded variation problems and also to a three-dimensional core case involving thermal feedback. The examination indicates that accurate direct whole core calculations with subpin level thermal feedback for practical PWR problems are quite possible on affordable LINUX clusters within a time span of a few hours.This work was supported by the International Nuclear Energy Research Initiative (I-NERI) program jointly funded by the Ministry of Science and Technology of Korea and the Department of Energy of the United States