Effects of duodenal-jejunal bypass on structure of diaphragm in western diet obese rats

Purpose: To evaluate the effects of duodenal-jejunal bypass (DJB) on the diaphragm muscle of obese rats fed on a western diet (WD) . Methods: Eighteen male Wistar rats were fed a standard rodent chow diet (CTL group) or WD ad libitum. After 10 weeks, WD rats were submitted to sham (WD SHAM) or duodenal-jejunal bypass (WD DJB). The structure, ultrastructure, collagen content and the morphometry of the neuromuscular junctions (NMJs) were analyzed two months after surgery. Results: WD SHAM rats displayed an increase in body weight, the Lee index and retroperitoneal and peri-epididymal fat pads compared to the CTL group. DJB did not alter these parameters. The muscle fiber structure and NMJs were similar in the WD SHAM and CTL groups. However, the WD SHAM group showed alterations in the fiber ultrastructure, such as loosely arranged myofibrils and Z line disorganization. In addition, WD SHAM animals presented a considerable amount of lipid droplets and a reduction in the percentage of collagen compared to the CTL group. DJB did not affect the structure or ultrastructure of the muscle fibers or the NMJs in the diaphragm of the WD DJB animals. Conclusion: Duodenal-jejunal bypass did not improve the alterations observed in the diaphragm of western diet obese-rats.(AU)

Miastenia gravis generalizada adquirida em cão relato de caso / Acquired generalized myastenia gravis in a doga case report

A Miastenia gravis adquirida pode desenvolver-se em qualquer raça canina e é considerado umdos principais distúrbios imunomediados que afetam o sistema neuromuscular dos cães, caracterizadaprincipalmente por fraqueza muscular e fadiga, que pioram com o exercício físico. Oprognóstico é reservado, principalmente quando associado à megaesôfago, devido ao risco depneumonia por aspiração que pode levar ao óbito. O diagnóstico torna-se muitas vezes desafiantedevido à similaridade com outras alterações neuromusculares. O diagnóstico definitivo é feitopela identificação de anticorpos antirreceptores de acetilcolina presentes no soro sanguíneo, maspode ser terapêutico, confirmado pela remissão dos sinais clínicos após tratamento com fármacosanticolinesterásicos. Este trabalho tem como objetivo relatar o caso de um cão com Miasteniagravis generalizada adquirida, ressaltando a importância do diagnóstico terapêutico feito combrometo de piridostigmina, bem como o acompanhamento de seus aspectos clínicos até completaremissão da doença.(AU)

The acquired myasthenia gravis can develop in any breed of dog and is considered one of the mostcommon immune-mediated disorders that affect the neuromuscular system of dogs, mainly characterizedby muscle weakness and fatigue that worsens during exercise. The prognosis is guarded,especially when associated with megaesophagus, due to risk of aspiration pneumonia that can leadto death. The diagnosis often becomes challenging due to the similarity to other neuromusculardisorders. The definitive diagnosis is done through the identification of antibodies against acetylcholinereceptors present in blood serum, but may be accomplished by remission of clinical signsafter administration of an anticholinesterase drug. This paper aims to reporting a case of a dogwith acquired generalized myasthenia gravis emphasizing the importance of therapeutic diagnosingmade by use of pyridostigmine bromide, and the monitoring of its clinical features until completeremission of the disease.(AU).

Miastenia gravis generalizada adquirida em cão – relato de caso / Acquired generalized myastenia gravis in a dog– a case report

A Miastenia gravis adquirida pode desenvolver-se em qualquer raça canina e é considerado umdos principais distúrbios imunomediados que afetam o sistema neuromuscular dos cães, caracterizadaprincipalmente por fraqueza muscular e fadiga, que pioram com o exercício físico. Oprognóstico é reservado, principalmente quando associado à megaesôfago, devido ao risco depneumonia por aspiração que pode levar ao óbito. O diagnóstico torna-se muitas vezes desafiantedevido à similaridade com outras alterações neuromusculares. O diagnóstico definitivo é feitopela identificação de anticorpos antirreceptores de acetilcolina presentes no soro sanguíneo, maspode ser terapêutico, confirmado pela remissão dos sinais clínicos após tratamento com fármacosanticolinesterásicos. Este trabalho tem como objetivo relatar o caso de um cão com Miasteniagravis generalizada adquirida, ressaltando a importância do diagnóstico terapêutico feito combrometo de piridostigmina, bem como o acompanhamento de seus aspectos clínicos até completaremissão da doença.

The acquired myasthenia gravis can develop in any breed of dog and is considered one of the mostcommon immune-mediated disorders that affect the neuromuscular system of dogs, mainly characterizedby muscle weakness and fatigue that worsens during exercise. The prognosis is guarded,especially when associated with megaesophagus, due to risk of aspiration pneumonia that can leadto death. The diagnosis often becomes challenging due to the similarity to other neuromusculardisorders. The definitive diagnosis is done through the identification of antibodies against acetylcholinereceptors present in blood serum, but may be accomplished by remission of clinical signsafter administration of an anticholinesterase drug. This paper aims to reporting a case of a dogwith acquired generalized myasthenia gravis emphasizing the importance of therapeutic diagnosingmade by use of pyridostigmine bromide, and the monitoring of its clinical features until completeremission of the disease..

Purification and n-terminal sequencing of two presynaptic neurotoxic PLA2, neuwieditoxin-I and neuwieditoxin-II, from Bothrops neuwiedi pauloensis (jararaca pintada) venom

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 (µBondapak 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 10µg/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% (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% homology with bothropstoxin-II and 54% homology with caudoxin) and that of NeuTX-II was SLFEFAKMILEETKRLPFPYYGAYGCYCGWGGQGQPKDAT (92% homology with Basp-III and 62% 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.