Electroestimulación neuromuscular intradiálisis, fuerza muscular, capacidad funcional y composición corporal / Intradialysis neuromuscular electro stimulation muscle strength, functional capacity and body composition

Introducción: La capacidad funcional disminuida y la importante atrofia muscular caracterizan a los pacientes en hemodiálisis (HD). El ejercicio físico intradiálisis y recientemente la electroestimulación neuromuscular (EMS), representan dos serias opciones terapéuticas para mejorar esta deteriorada condición física. Actualmente, no existen estudios publicados sobre el papel de la EMS y la composición corporal en los pacientes en HD. Objetivo: Analizar que efecto produce un programa de EMS sobre la fuerza muscular, capacidad funcional, parámetros nutricionales y composición corporal en nuestros pacientes en HD. Material y Métodos: Estudio unicéntrico, prospectivo de 12 semanas de duración. Los pacientes incluidos realizaron un programa adaptativo de EMS en ambos cuádriceps intradiálisis mediante el dispositivo Compex R Theta 500i. Analizamos: 1.- Parámetros nutricionales (Albumina, pre albúmina, triglicéridos, colesterol total y fracciones, ferritina y Proteína C reactiva). 2.- Datos musculares: Composición muscular cuadriceps, Fuerza extensión máxima cuádriceps (FEMQ) y handgrip (HG) brazo dominante. 3.- Test funcionales: “Sit to stand to sit” (STS10) y “six- minutes walking test” (6MWT). 4.- Composición corporal mediante biompedancia electrica (BIA). Resultados: 13 pacientes incluidos: (69.2% hombres). Edad media: 65.7 años y 33.9 meses en HD. I.Charlson medio 9.1. La principal etiología de la ERC fue la DM ( 38.5%). Al final del estudio se observó una mejoría en (*p<0.05): FEMQ* ( 11.7±7.1 vs 13.4±7.4 Kg), STS10 (39.3±15.5 vs 35.8±13.7 seg), 6MWT* (9.9%, 293.2 vs 325.2 m). En relación a la composición corporal, se observó únicamente un aumento significativo del área muscular (AMQ*: 128.6 ± 30.2 vs 144.6 ± 22.4 cm2) y una disminución del área grasa (AGQ*: 76.5 ± 26.9 vs 62.1 ± 20.1 cm2) a nivel quadricipital, sin cambios en el resto de datos analizados (% grasa abdominal, peso graso, peso magro, agua corporal total). No se objetivaron cambios relevantes en los parámetros nutricionales y de adecuación dialítica. Conclusiones: 1.- La electroestimulación neuromuscular intradialísis mejoró la fuerza muscular, la capacidad funcional y la composición muscular del cuadriceps de nuestros pacientes en HD. 2.- Nuestros resultados remarcan el carácter local de la electroes-timulación neuromuscular, dada la ausencia de cambios relevantes en el resto de los parámetros nutricionales y datos corporales analizados. 3.- No obstante, son necesarios futuros estudios mejor diseñados, de cara a discernir si la electroestimulación neuromuscular podría ser una nueva alternativa terapéutica para evitar la atrofia muscular y el deterioro progresivo de la condición física de éstos pacientes (AU)

Background: The reduced functional capacity and significant muscle atrophy characterized patients on hemodialysis. Intradialytic exercise and recently neuromuscular electrostimulation (EMS) represent two serious therapeutical options to improve the deteriorated physical condition. Until date, there are no published studies about the role of EMS and body composition in HD patients. Objectives: Analyze the effect a program of EMS on muscle strength, functional capacity, nutritional parameters and body composition in our HD patients. Methods: A 12 weeks single-center, prospective study. Patients included in the study performed an intradialysis EMS adaptive program in both quadriceps using the Compex R Theta 500i device. We analyzed: 1.- Nutritional parameters (albumin, pre-albumin, triglycerides, total cholesterol and fractions, ferritin and C-reactive protein). 2.- Muscular data: Muscular composition, Maximum length quadriceps strength (MLQS) and “hand-grip” (HG) dominant arm. 3.- Functional capacity test: “Sit to stand to sit” (STS10) and “six- minutes walking test” (6MWT). 4.- Body composition. Results: 13 HD patients included: 69.2 % men. Mean age 65.7 years and 33.9 months on HD. A significant (* p < 0,05) improvement was observed in MLQS* (11.7±7.1 vs 13.4±7.4 Kg), STS10* (39.3±15.5 vs 35.8±13.7 seg), 6MWT* (9.9%, 293.2 vs 325.2 m). There was a signi-ficant increase in the quadriceps muscular area (QMA*: 128.6 ± 30.2 vs 144.6 ± 22.4 cm2) and decrease of fat quadricipital area (FQA*: 76.5 ± 26.9 vs 62.1 ± 20.1 cm2). No significant changes were observed in nutritional parameters, body composition (body fat percentage, lean and fat mass, total body water) or dialysis adecuacy data. Conclusions: 1.- Intradialysis quadriceps EMS improved muscle strength, functional capacity and the quadriceps muscle composition in our HD patients. 2.- Our results underline the local aspects on EMS, given the absence of relevant changes on nutritional parameters and body composition. 3.- Future studies are manadatory in order to establish if EMS could be a new alternative to prevent muscle atrophy and the progressive deterioration of the physical condition of these patients (AU)

Structural and functional studies of a bothropic myotoxin complexed to rosmarinic acid: new insights into Lys49-PLA2 inhibition.

Snakebite envenoming is an important public health problem in many tropical and subtropical countries, and is considered a neglected tropical disease by the World Health Organization. Most severe cases are inflicted by species of the families Elapidae and Viperidae, and lead to a number of systemic and local effects in the victim. One of the main problems regarding viperidic accidents is prominent local tissue damage whose pathogenesis is complex and involves the combined actions of a variety of venom components. Phospholipases A2 (PLA2s) are the most abundant muscle-damaging components of these venoms. Herein, we report functional and structural studies of PrTX-I, a Lys49-PLA2 from Bothops pirajai snake venom, and the influence of rosmarinic acid (RA) upon this toxin's activities. RA is a known active component of some plant extracts and has been reported as presenting anti-myotoxic properties related to bothopic envenomation. The myotoxic activity of Lys49-PLA2s is well established in the literature and although no in vivo neurotoxicity has been observed among these toxins, in vitro neuromuscular blockade has been reported for some of these proteins. Our in vitro studies show that RA drastically reduces both the muscle damage and the neuromuscular blockade exerted by PrTX-I on mice neuromuscular preparations (by ∼80% and ∼90%, respectively). These results support the hypothesis that the two effects are closely related and lead us to suggest that they are consequences of the muscle membrane-destabilizing activity of the Lys49-PLA2. Although the C-terminal region of these proteins has been reported to comprise the myotoxic site, we demonstrate by X-ray crystallographic studies that RA interacts with PrTX-I in a different region. Consequently, a new mode of Lys49-PLA2 inhibition is proposed. Comparison of our results with others in the literature suggests possible new ways to inhibit bothropic snake venom myotoxins and improve serum therapy.