Verapamil-associated cardiogenic shock in a 71-year-old man with myasthenia gravis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Myasthenia gravis is a rare neuromuscular disorder associated with a reduction in the availability of acetylcholine receptors at the post-synaptic membranes of skeletal muscles. This is caused by the production of anti-acetylcholine receptor antibodies at the neuromuscular junction due to an autoimmune insult, leading to a compromised neuromuscular transmission. Verapamil can influence, in a dose-dependent fashion, the neuromuscular transmission in myasthenia gravis.</p> <p>Case presentation</p> <p>We report a 71-year-old Caucasian man with myasthenia gravis suffering from a cardiogenic shock following a single dose of verapamil. The patient had uncontrolled atrial fibrillation with a heart rate of 120 beats/min. Atenolol 100 mg was started. The next day, verapamil SR 240 mg was started. Two hours after the first dose of verapamil, the patient complained of weakness and dyspnea with signs of shock; his blood pressure was 70/50 mm Hg and heart rate at 101 beats/min. An echocardiogram showed diffuse hypokinesis of both ventricles with an ejection fraction of 20%. Cardiac catheterization was performed and coronary arteries appeared without significant stenosis, but there was a diffuse hypokinesis. Verapamil was stopped and the patient received intravenous glucagon and calcium chloride. Both the anti-acetylcholine receptor and anti-striated muscle antibodies tested positive. A few hours later, another echocardiogram showed an improvement in the ventricular function, which returned to normal five days later.</p> <p>Conclusion</p> <p>Caution is needed when administering verapamil to patients with myasthenia gravis, especially when the anti-acetylcholine receptor and anti-striated muscle antibodies titres are positive.</p

Novel Insights Regarding the Operational Characteristics and Teleological Purpose of the Renal Na+-K+-Cl2 Cotransporter (NKCC2s) Splice Variants

The absorptive Na+-K+-Cl− cotransporter (NKCC2) is a polytopic protein that forms homooligomeric complexes in the apical membrane of the thick ascending loop of Henle (TAL). It occurs in at least four splice variants (called B, A, F, and AF) that are identical to one another except for a short region in the membrane-associated domain. Although each of these variants exhibits unique functional properties and distributions along the TAL, their teleological purpose and structural organization remain poorly defined. In the current work, we provide additional insight in these regards by showing in mouse that the administration of either furosemide or an H2O-rich diet, which are predicted to alter NKCC2 expression in the TAL, exerts differential effects on mRNA levels for the variants, increasing those of A (furosemide) but decreasing those of F and AF (furosemide or H2O). Based on a yeast two-hybrid mapping analysis, we also show that the formation of homooligomeric complexes is mediated by two self-interacting domains in the COOH terminus (residues 671 to 816 and 910 to 1098), and that these complexes could probably include more than one type of variant. Taken together, the data reported here suggest that A, F, and AF each play unique roles that are adapted to specific physiological needs, and that the accomplishment of such roles is coordinated through the splicing machinery as well as complex NKCC2–NKCC2 interactions

La collaboration dans la pratique du travail de rue : l’expérience de Rouyn-Noranda

Cet article illustre la spécificité d’une pratique du travail de rue dans un centre urbain de petite taille d’une région dite éloignée. Il rend compte d’une recherche analysant la démarche d’implantation du travail de rue à Rouyn-Noranda, de même que la collaboration établie entre les travailleurs de rue et les personnes intervenant auprès des jeunes. Le propos s’articule autour de trois axes : les mécanismes pour établir la collaboration, les types de collaboration, notamment la référence, et les transformations souhaitables dans le réseau de la santé et des services sociaux pour mieux rejoindre les jeunes marginalisés.This paper illustrates the peculiarities of outreach work in a small town in a rural and remote region. It focuses on a research project to assess the implementation of outreach work in Rouyn-Noranda, and on the collaborative relationships between outreach workers and people working with youth. Three components are analyzed : how cooperation was established, what types of cooperation are used (including referrals), and desirable changes in the health and social services system to better reach out to marginalized youngsters