ABSTRACT
Introducción: La utilización de agentes biológicos para el tratamiento de la Artritis Reumatoidea (AR) es habitualmente usada en aquellos pacientes con enfermedad activa que no hayan respondido al tratamiento con drogas modificadoras de la Artritis Reumatoidea convencionales (DMARD, por sus siglas en inglés) o que hayan presentado intolerancia a las mismas. Al estado actual de la evidencia, la terapia combinada de agentes biológicos más un DMARD convencional (principalmente metotrexato) constituye el estándar de tratamiento. Sin embargo existen algunos escenarios como la intolerancia, la falta de adherencia y la aparición de eventos adversos a las DMARDs convencionales donde la monoterapia biológica emerge como una opción terapéutica válida. Según los distintos registros a nivel internacional, la frecuencia de utilización de agentes biológicos en monoterapia oscila entre 12 a 39%. Debido a la ausencia de estos datos a nivel local decidimos realizar este estudio para conocer el porcentaje de pacientes que se encuentran en monoterapia biológica y analizar las causas que llevaron a este tipo de tratamiento. Materiales y métodos: Estudio de tipo corte transversal donde se invitó a participar a diferentes centros reumatológicos distribuidos a lo largo de Argentina. Cada centro revisó las historias clínicas de los últimos 30 a 50 pacientes consecutivos vistos con AR, mayores de 18 años, que habían presentado inadecuada respuesta al tratamiento con DMARDs y que estaban bajo tratamiento biológico. Se completaba una ficha por cada paciente incluido, registrando datos demográficos, de la enfermedad y tratamientos previos. Resultados: Se incluyeron 32 centros y se evaluaron 1148 historias clínicas de pacientes con AR durante el mes de octubre y noviembre del 2012. Un 21,4% (246) de los pacientes al momento del estudio se encontraba bajo tratamiento biológico en monoterapia...
Introduction: The use of biological agents for the treatment of rheumatoid arthritis (RA) is commonly used in patients with active disease who have not responded to treatment with conventional rheumatoid arthritis-modifying drugs (DMARDs) or Who have presented intolerance to them. At the present state of evidence, combined therapy of biological agents plus conventional DMARD (mainly methotrexate) is the standard of treatment. However, there are some scenarios such as intolerance, lack of adherence and the appearance of adverse events to conventional DMARDs where biological monotherapy emerges as a valid therapeutic option. According to different international registries, the frequency of use of biological agents in monotherapy ranges from 12 to 39%. Due to the absence of these data at the local level we decided to carry out this study to know the percentage of patients who are in biological monotherapy and to analyze the causes that led to this type of treatment. Materials and methods: A cross-sectional study where different rheumatologic centers throughout Argentina were invited to participate. Each center reviewed the medical records of the last 30 to 50 consecutive patients seen with RA, older than 18 years, who had inadequate response to treatment with DMARDs and who were under biological treatment. One card was completed for each patient included, recording demographic, disease and previous treatment data. Results: Thirty-two centers were included and 1148 clinical records of patients with RA were evaluated during October and November 2012. A total of 244 patients (246) at the time of the study were under monotherapy...
Subject(s)
Arthritis, Rheumatoid , Biological Treatment , ArgentinaABSTRACT
Two presynaptic phospholipases A2 (PLA2), neuwieditoxin-I (NeuTX-I) and neuwieditoxin-II (NeuTX-II), were isolated from the venom of Bothrops neuwiedi pauloensis (BNP). The venom was fractionated using molecular exclusion HPLC (Protein-Pak 300SW column), followed by reverse phase HPLC (æBondapak C18 column). Tricine-SDS-PAGE in the presence or absence of dithiothreitol showed that NeuTX-I and NeuTX-II had a molecular mass of approximately 14 kDa and 28kDa, respectively. At 10æg/ml, both toxins produced complete neuromuscular blockade in indirectly stimulated chick biventer cervicis isolated preparation without inhibiting the response to acetylcholine, but NeuTX-II reduced the response to KCl by 67.0±8.0 percent (n=3; p<0.05). NeuTX-I and NeuTX-II are probably responsible for the presynaptic neurotoxicity of BNP venom in vitro. In fact, using loose patch clamp technique for mouse phrenic nerve-diaphragm preparation, NeuTX-I produced a calcium-dependent blockade of acetylcholine release and caused appearance of giant miniature end-plate potentials (mepps), indicating a pure presynaptic action. The N-terminal sequence of NeuTX-I was DLVQFGQMILKVAGRSLPKSYGAYGCYCGWGGRGK (71 percent homology with bothropstoxin-II and 54 percent homology with caudoxin) and that of NeuTX-II was SLFEFAKMILEETKRLPFPYYGAYGCYCGWGGQGQPKDAT (92 percent homology with Basp-III and 62 percent homology with crotoxin PLA2). The fact that NeuTX-I has Q-4 (Gln-4) and both toxins have F-5 (Phe-5) and Y-28 (Tyr-28) strongly suggests that NeuTX-I and NeuTX-II are Asp49 PLA2.
Subject(s)
Animals , Bothrops/metabolism , Crotalid Venoms , Phospholipases A/chemistry , Neurotoxins/poisoningABSTRACT
The existence of a modulatory system controlling the acetylcholine (ACh) release was first proposed for the nicotinic subtype in 1962. Following the first observation of a possible positive feedback loop activated by the released Ach, many studies were oriented in the investigation of the involved presynaptic autoreceptors. Most of the data have been obtained at the motor end-plate, commonly defined as the simplest model of peripheral synapse. The characterization of the chemical transmission since its first proposal showed a more complex pattern involving both the cholinergic and the adrenergic systems. It is now evident that this regulation is widespread both in the central and in the peripheral nervous system. The evidence that the release of ACh can be up- or down-regulated by the transmitter itself (autoregulation) or other neuromediators (heteroregulation) is now proved. In the last decades the attention was focused to the identification of the receptor subtypes located on the releasing nerve terminal. For the purpose, different techniques were used in the various laboratories. The functional approach was based mainly on the electrophysiological characterization of the events evolved prior, during and after the activation of the motor endplate nicotinic receptor. On the other hand, the overflow studies were carried out using radiolabeled ACh (rACh) obtained treating muscle fibers with radioactive choline (rCh). Many scientific papers proposed common data indicating a clear positive (nicotinic) or negative (muscarinic) modulation of the ACh release. Temporally, the description of the muscarinic regulation followed the discovery of the nicotinic one. However, by a pure pharmacological point of view it represents a challenge due to the more complex organization and function. In the peripheral nervous system, i.e. neuromuscular, the meaning of both the muscarinic and nicotinic modulations may appear as free of function. Conversely, in the central systems some effects, such as antinociception and others, could represent the basis of a functional activity such as proposed by Corrado group. The complete characterization of this phenomenon by a physiological and a pharmacological point of view could represents the goal for future uses and therapeutic potential. The present review illustrates the know how and the efforts in the characterisation of the muscarinic regulation of transmitter release from the beginning of its discovery trying to order the numerous scientific data published in this field. Furthermore, our personal data obtained with the Loose Patch Clamp (LPC) technique will be briefly presented and discussed. Our work was built up using agonists and antagonists of the muscarinic receptor subtype in the aim of better characterize the modulation function of the mediator Ach. We used carbachol (Cch), oxotremorine (Oxo) and dl-muscarine as agonists and 1-hyoscyamine, pirenzepine, ipratropium, 11[[2-1[(diethylamino) methyl-1-piperidinyl]-acetyl]-5, 11-dihydro-6H-pyrido [2,3-b][1,4] benzodiazepine-6-one (AFDX-116), methoctramine and 1,1-dimethyl-4 diphenylacetoxy-N-methylpiperidine (4-DAMP) as antagonists.