Pancreatic islet transplantation is a well-established therapeutic treatment for type 1 diabetes. The kidney capsule is the most commonly used site for islet transplantation in rodent models. However, the tight kidney capsule limits the transplantation of sufficient islets in large animals and humans. The inguinal subcutaneous white adipose tissue (ISWAT), a new subcutaneous space, was found to be a potentially valuable site for islet transplantation. This site has better blood supply than other subcutaneous spaces. Moreover, the ISWAT accommodates a larger islet mass than the kidney capsule, and transplantation into it is simple. This manuscript describes the procedure of mouse islet isolation and transplantation in the ISWAT site of syngeneic diabetic mouse recipients. Using this protocol, murine pancreatic islets were isolated by standard collagenase digestion and a basement membrane matrix hydrogel was used for fixing the purified islets in the ISWAT site. The blood glucose levels of the recipient mice were monitored for more than 100 days. Islet grafts were retrieved at day 100 after transplantation for histological analysis. The protocol for islet transplantation in the ISWAT site described in this manuscript is simple and effective.
Controversial results regarding the associations between aldose reductase (AR) genetic polymorphisms and diabetic retinopathy (DR) have been reported for many years. The present meta-analysis was performed to clarify the effects of the AR gene C(-106)T polymorphism on DR risk. The PubMed, Web of Sciences, Cochrane library, EMBASE, Chinese National Knowledge Infrastructure, and Wan Fang databases were extensively searched in Chinese to select relevant studies with an updated date of April 25, 2018. The Newcastle-Ottawa Scale (NOS) was applied to assess quality. The random-effects model was applied to calculate the pooled OR and 95% CI. This meta-analysis identified 23 studies with an average score of 7.52 for NOS analysis, including 4,313 DR cases and 5,128 diabetes mellitus (DM) control cases. In the overall analysis, a significant association between the AR gene C(-106)T polymorphism and DR susceptibility was found. In subgroups stratified by DM type and ethnicity, significantly increased risks for DR were found in DM type 1, East Asian populations, and Middle Eastern populations. Compared with DR control cases, the following associations were found: T vs. C: OR 0.91, 95% CI 0.85-0.97, I-2 = 72.9%; CT + TT vs. CC: OR 0.75, 95% CI 0.68-0.81, I-2 = 86.7%; and CT vs. CC: OR 0.86, 95% CI 0.78-0.94, I-2 = 70.5%. The results of this meta-analysis showed a significant association between the AR gene C(-106)T polymorphism and susceptibility to DR in DM patients. DM patients with allele T and CT+TT genotype of the AR gene may have a lower risk of DR.
Purpose: Single-field non-mydriatic fundus photography (NMFP) has been used to detect diabetic retinopathy (DR) in many studies; however, its value in a general clinical setting has not been established. Here we performed a meta-analysis to evaluate its diagnostic effectiveness. Method: We systematically searched PubMed, EMBASE, and Cochrane databases for candidate studies published through May 19, 2018. A random-effect model was used to calculate the diagnostic indicators including the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), area under the curve (AUC), and 95% confidence intervals. Results: Ten prospective studies were ultimately included. The pooled sensitivity, specificity, PLR, NLR, and DOR were 0.68, 0.94, 11.2, 0.34 and 33, respectively. The AUC was 0.88. Subgroup analysis showed that single-field NMFP had a respective sensitivity and specificity of 0.73 and 0.91 when compared to standard 7-field mydriatic stereoscopic photography (7SF), and 0.54 and 0.98 when compared to slit-lamp biomicroscopy as reference standard. Conclusions: Single-field NMFP is inadequate to detect DR. Additionally, it showed higher sensitivity and lower specificity when 7SF was used as reference standard, as compared to slit-lamp biomicroscopy, suggesting that different reference standards used in DR screening might have affected the diagnostic results.