Brugada pattern electrocardiogram associated with supratherapeutic phenytoin levels and the risk of sudden death

The emergence of Brugada pattern on electrocardiogram in response to class IA or IC antiarrhythmic agents is widely utilized to diagnose concealed Brugada syndrome and recognized as a risk factor for sudden death. Phenytoin, a class IB antiarrhythmic agent, has not been reported to induce Brugada pattern. We report a patient who presented with Brugada electrocardiogram at supratherapeutic phenytoin level. Considering that patients with syncope may falsely be labeled to have seizures and some epilepsy patients are at increased risk of sudden death, all patients with supratherapeutic phenytoin level should be evaluated with an electrocardiogram for emergence of Brugada pattern.     

The impact of COVID-19 pandemic on rheumatology practice: a cross-sectional multinational study

Clinical Rheumatology - To evaluate the impact of the coronavirus disease 2019 (COVID-19) pandemic on rheumatology practice. A cross-sectional web survey was designed by the members of the Arab...     

Subcoronary implantation of a stentless valve in patients with aortic aneurysms

Experience with a new operation for patients with aortic valve disease and aneurysm or dissection of the ascending aorta is described. Twenty-four patients aged 66-87 years were operated on using a subcoronary implantation technique with a stentless aortic valve bioprosthesis and an extension using a vascular tube prosthesis. No major adverse cardiac events were observed in the postoperative period. This operation offers a safe alternative to the technically more demanding procedures of composite bioprosthetic ascending aortic replacement or full root replacement.     

Association of Piebaldism,Multiple Café‐au‐lait Macules,and Intertriginous Freckling: Clinical Evidence of a Common Pathway between KIT and Sprouty‐Related,Ena/Vasodilator‐Stimulated Phosphoprotein Homology‐1 Domain Containing Protein 1 (SPRED1)

Abstract: Piebaldism is a rare genodermatosis caused by KIT mutations. We report the case of a 5‐year‐old boy who had the white forelock and leukoderma of piebaldism, but the presence of many café‐au‐lait macules and axillary and inguinal freckling complicated the diagnosis. Patients with similar cutaneous findings have been previously reported, and their disorder has been attributed to an overlap of piebaldism and neurofibromatosis type 1. Legius syndrome is a recently described syndrome caused by Sprouty‐related, Ena/vasodilator‐stimulated phosphoprotein homology‐1 domain containing protein 1 (SPRED1) mutations that also has multiple café‐au‐lait macules and intertriginous freckling. Based on our current understanding of KIT and SPRED1 protein interactions, we propose that café‐au‐lait macules and freckling may be seen in some patients with piebaldism and does not necessarily represent coexistence of neurofibromatosis type 1.     

Evidence for the requirement for CD40-CD154 interactions in resistance to infections with attenuated Salmonella

Salmonella species include facultative intracellular pathogens which reside preferentially within cells of the host's reticulo-endothelial system. Resistance to Salmonella involves a collaboration between cells of the innate and adaptive immune systems, and protective immunity requires cell-mediated and humoral-immune responses. CD40-CD154 interactions are of central importance in the induction of cellular immune responses. In the present study, CD154-deficient (CD154(-/-)) mice were used to assess the role of CD40-CD154 interactions in immunity to Salmonella infection. Compared to C57BL/6 (CD154(+/+)) controls, CD154(-/-) mice were hypersusceptible to infection by an attenuated strain of Salmonella enterica serovar Typhimurium (S. typhimurium), as evidenced by a significantly decreased survival rate. CD154(-/-) mice exhibited a defect in the production of IFN-gamma and NO in the acute phase of the disease, which resulted in a failure to control bacterial replication. We conclude that intercellular communications via the CD40-CD154 pathway play a critical role in the induction type-1 cytokine responses and protection against primary infections with attenuated Salmonella.     

Evidence for a dual pathway of activation in CD43-stimulated Th2 cells: differential requirement for the Lck tyrosine kinase

CD43 is the most abundant cell surface-expressed sialoglycoprotein on T lymphocytes. Despite evidence demonstrating the activation of some signaling components by CD43, the exact function of CD43 in T cell biology remains controversial. In this study, we demonstrate that the sole ligation of CD43 in cloned Th2 cells resulted in cytokine production, cellular proliferation, and upregulation of CD25 and CD69 activation markers. Similarly, cross-linking of CD43 on naive splenic T cells led to a significant proliferative response and an enhancement of the expression of CD25 and CD69 markers. These responses required no additional signals from other T cell molecules, including TCR. In Lck-deficient Th2 cells, however, CD43 ligation led to IL-4 production and an increase in the expression of CD25 and CD69 antigens but, surprisingly, no proliferation. Analysis of signaling pathway components revealed that CD43 associates with the adaptor protein SLP-76 within 30 s of activation. This induces the tyrosine phosphorylation of SLP-76 and promotes the recruitment and phosphorylation of another adaptor, Shc. The formation of this multi-component complex was strictly dependent on Lck. In contrast, comparison of tyrosine phosphorylated proteins in whole extracts of normal and Lck-deficient cells revealed a strikingly similar pattern of phosphorylation involving two major protein bands at 26 and 78 kDa. This suggests that tyrosine kinases other than Lck are activated by CD43 ligation. Taken together, the data support the notion that CD43 ligation may induce a dual pathway leading to the activation of different effector functions in Th2 lymphocytes.