RESUMO
Self-expanding metal stents (SEMS) are currently the standard for palliation of malignant dysphagia. Innovations in stent technology, including the advent of retrievable stents and the development of self-expanding plastic stents (SEPS), show promise to increase the possible applications for esophageal stents. This article reviews the indications and usage of both SEMS and SEPS in patients with malignant dysphagia as well as the potential complications of their use.
Assuntos
Transtornos de Deglutição/cirurgia , Cuidados Paliativos/métodos , Stents , Constrição Patológica/etiologia , Constrição Patológica/cirurgia , Transtornos de Deglutição/etiologia , Desenho de Equipamento , Neoplasias Esofágicas/complicações , Humanos , Stents/efeitos adversos , Resultado do TratamentoRESUMO
Mutations in the pancreatic ATP-sensitive potassium (K(ATP)) channel subunits sulfonylurea receptor 1 (SUR1) and the inwardly rectifying potassium channel Kir6.2 cause persistent hyperinsulinemic hypoglycemia of infancy. We have identified a SUR1 mutation, L1544P, in a patient with the disease. Channels formed by co-transfection of Kir6.2 and the mutant SUR1 in COS cells have reduced response to MgADP ( approximately 10% that of the wild-type channels) and reduced surface expression ( approximately 19% that of the wild-type channels). However, the steady-state level of the SUR1 protein is unaffected. Treating cells with lysosomal or proteasomal inhibitors did not improve surface expression of the mutant channels, suggesting that increased degradation of mutant channels by either pathway is unlikely to account for the reduced surface expression. Removal of the RKR endoplasmic reticulum retention/retrieval trafficking motif in either SUR1 or Kir6.2 increased the surface expression of the mutant channel by approximately 35 and approximately 20%, respectively. The simultaneous removal of the RKR motif in both channel subunits restored surface expression of the mutant channel to the wild-type channel levels. Thus, the L1544P mutation may interfere with normal trafficking of K(ATP) channels by causing improper shielding of the RKR endoplasmic reticulum retention/retrieval trafficking signals in the two channel subunits.
