ABSTRACT
Peripheral nerve injuries represent a great challenge for surgeons. The conductive neural scaffold has experienced increasing interest because of its good biocompatibility and similar electrical properties as compared to those of a normal nerve. Herein, nerve conduits made from poly(d,l-lactide)-co-poly(ethylene glycol) and polypyrrole (20%, 30%, and 50%) (PELA-PPY) were prepared by electrospinning, and used in regeneration of peripheral nerve defects. The results of an in vitro experiment indicated a high biocompatibility for the as-prepared materials, supporting the attachment and proliferation of a rat pheochromocytoma PC-12 cell. Furthermore, the PELA-PPY nerve conduit implanted in the sciatic nerve defects (10 mm) of the Spraguee-Dawley rats for 12 weeks showed similar results with the autograft, while it demonstrated a better outcome than the PELA nerve conduit in electrophysiological examination, sciatic function index, total amount of regenerated myelinated nerve fibers, axon diameter, myelin thickness, and several immunohistochemistry indices (S-100, laminin, neurofilament, bromodeoxyuridine, and glial fibrillary acidic portein). We supposed that the bioactivity is mainly generated by the PPY in composite nanofibers which could transmit self-originated electrical stimulation between cells. Due to the facile preparation and excellent in vivo performance, the PPY-PELA nerve conduit is promising for use as a bioengineered biomaterial for peripheral nerve regeneration.
ABSTRACT
PURPOSE: The purpose of this systematic meta-analysis was to evaluate the association between leptin (LEP) and leptin receptor (LEPR) gene polymorphisms and non-Hodgkin lymphoma (NHL) risk. METHODS: All studies published up to July 2014 on the association between LEP and LEPR polymorphisms and NHL risk were identified by searching PubMed, Web of Science, EMBASE, and Google Scholar. Odds ratios (ORs) with 95% confidence intervals (CIs) for LEP and LEPR polymorphisms and NHL were calculated with fixed-effects and random-effects models. RESULTS: LEP G2528A polymorphism was associated with increased, yet not statistically significant risk of NHL (homozygote comparison, OR=1.27, 95% CI=1.01-1.60, p=0.63; heterozygote comparison, OR=1.13, 95% CI=0.86-1.49, p=0.14; dominant model, OR=1.18, 95% CI=0.99-1.41, p=0.21; recessive model, OR=1.18, 95% CI=0.97-1.43, p=0.78; additive model, OR=1.14, 95% CI=1.01-1.28, p=0.52). Significant decrease of NHL risk was found in LEP A19G polymorphism, while no links were detected with the LEPR polymorphisms studied. In subgroup analysis, the pooled results showed that LEP A19G polymorphism was associated with decreased risk of follicular lymphoma (FL) (homozygote comparison, OR=0.56, 95% CI=0.37-0.85, p=0.69). However, no evidence of a significant association was observed in diffuse large B-cell lymphoma (DLBCL) for variant genotypes of all single nucleotide polymorphisms (SNPs). CONCLUSIONS: LEP G2548A polymorphism contributes to NHL susceptibility. Also, our results provide evidence that LEP A19G polymorphism is associated with decreased risk of NHL, especially in FL. Further large-scale and well-designed studies are needed to confirm this association.
Subject(s)
Leptin/genetics , Lymphoma, Non-Hodgkin/genetics , Polymorphism, Single Nucleotide , Receptors, Leptin/genetics , Chi-Square Distribution , Genetic Predisposition to Disease , Heterozygote , Homozygote , Humans , Lymphoma, Non-Hodgkin/diagnosis , Lymphoma, Non-Hodgkin/ethnology , Lymphoma, Non-Hodgkin/prevention & control , Odds Ratio , Protective Factors , Risk FactorsABSTRACT
Previous studies have shown conflicting results between the association of leptin receptor (LEPR) genetic polymorphisms and cancer risk. The frequent LEPR Lys656Asn or Ser343Ser genetic polymorphism has been demonstrated to be functional and may promote genetic susceptibility to cancers. However, the association between the LEPR Lys656Asn or Ser343Ser genetic polymorphism and cancer risk remains to be determined. To improve the understanding of the LEPR Lys656Asn or Ser343Ser genetic polymorphism role in global cancer, a comprehensive meta-analysis was conducted that comprised 2,480 cases and 3,162 controls. The LEPR Lys656Asn or Ser343Ser genetic polymorphism did not significantly affect the cancer risk. In the stratified analysis, there was no significant association of the LEPR Lys656Asn or Ser343Ser variants with any type of cancer under any model. In addition, significantly increased risks were found in the Asian population in heterozygous codominant [odds ratio (OR), 1.24 (1.01-1.53)] and dominant [OR, 1.24 (1.02-1.50)] genetic models. A significantly increased susceptibility to cancer was not found when stratified by study design. There were no significant differences found in genotype method and sample size in cases among the genotypes. These findings indicated a lack of association between LEPR Lys656Asn or Ser343Ser polymorphisms and cancer susceptibility, however, these polymorphisms may increase the cancer susceptibility among the Asian population, particularly in the dominant genetic model. The single-nucleotide polymorphism is also suggested to function as a dominant mutation, which requires verification or association with functional studies.
