RESUMO
The identification of risk factors for acute rejection (AR) may lead to strategies to improve success of kidney transplantation. Ectonucleotidases are ectoenzymes that hydrolyze extracellular nucleotides into nucleosides, modulating the purinergic signaling. Some members of the Ectonucleotidase family have been linked to transplant rejection processes. However, the association of Ectonucleotide Pyrophosphatase / Phosphodiesterase 1 (ENPP1) with AR has not yet been evaluated. The aim of this study was to evaluate the association between the K121Q polymorphism of ENPP1 gene and AR in kidney transplant patients. We analyzed 449 subjects without AR and 98 with AR from a retrospective cohort of kidney transplant patients from Southern Brazil. K121Q polymorphism was genotyped using allelic discrimination-real-time PCR. Cox regression analysis was used to evaluate freedom of AR in kidney transplant patients according to genotypes. Q allele frequency was 17.6% in recipients without AR and 21.9% in those with AR (P = 0.209). Genotype frequencies of the K121Q polymorphism were in Hardy-Weinberg equilibrium in non-AR patients (P = 0.70). The Q/Q genotype (recessive model) was associated with AR (HR = 2.83, 95% CI 1.08-7.45; P = 0.034) after adjusting for confounders factors. Our findings suggest a novel association between the ENPP1 121Q/Q genotype and AR in kidney transplant recipients.
Assuntos
Rejeição de Enxerto/enzimologia , Rejeição de Enxerto/genética , Transplante de Rim/efeitos adversos , Diester Fosfórico Hidrolases/genética , Pirofosfatases/genética , Doença Aguda , Substituição de Aminoácidos , Brasil , Estudos de Casos e Controles , Estudos de Coortes , Frequência do Gene , Genes Recessivos , Estudos de Associação Genética , Humanos , Modelos Genéticos , Polimorfismo de Nucleotídeo Único , Estudos RetrospectivosRESUMO
OBJECTIVE: This work evaluated sciatic nerve regeneration after cryotherapy. STUDY DESIGN: Rats underwent surgical access of the sciatic nerve and subsequent cryotherapy, crush lesion, or no manipulation. Walking-track, electroneuromyographic, and histomorphometric analyses were performed at 15, 30, and 70 postoperative days. RESULTS: At 15 days, the crush and cryotherapy groups showed significant morphofunctional impairment. At 30 days, functional loss was significant in the walking-track, but at 70 days, there were no significant differences between the groups. Amplitude was near zero for the crush group at 15 and 30 days and zero for the cryotherapy group. Measurement of latency was not possible in the latter group. Crush and cryotherapy groups showed greater amounts of myelinated fibers (by 30 days), with axonal diameter and width of the myelin sheath being less than in control group. CONCLUSIONS: Sciatic nerve lesion by application of liquid nitrogen is classified as axonotmesis, which is reversible.
