【Abstract】ObjectiveTo investigate the effect of xenotransplantation of microencapsulated rabbit parathyroid tissue in different sites in rats for the treatment of hypoparathyroidism. MethodsThe parathyroid glands from Wistar rats were removed to make them aparathyroid. Ultimately, sixteen rats were included because their serum calcium values were continuously below 1.6 mmol/L. We also encapsulated the cultured rabbit parathyroid tissue with alginateBaCl2 microcapsule. According to the transplantation sites, rats were randomly divided into two groups: renal adipose microcapsule group and peritoneal microcapsule group, eight in each group. Encapsulated rabbit parathyroid tissues were then transplanted accordingly to different microcapsule groups. The calcium serum contents were examined on 5，15，25，35，45，55 and 65 d respectively after transplantation and the grafts were observed through electron microscope on the 65 d in particular. ResultsThe calcium contents after transplantation in renal adipose microcapsule group restored to normal and the observation outcomes of grafts showed that they survived well. The calcium contents of posttransplantation in peritoneal group also restored to normal with an exception that it dropped to a level lower than 1.6 mmol/L on the 65 d. Electron microscope also showed that there were necrotic tissues in the center and only a few cells survived on the edge of the grafts. Within peritoneal microcapsule group, the values were significantly lower than others taken at different phases. ConclusionMicroencapsulated rabbit parathyroid tissue that was xenotransplanted into rats can survive and function without administration of immunodepressant. There are significant differences of calcium contents at varying phases between two transplantation sites, which demonstrate that renal adipose may be an optimal site for microcapsule xenotransplantation.
Randomized controlled trials (RCTs) are currently the gold standard for the treatment effect comparisons; however, it is sometimes not feasible to conduct an RCT due to ethical and economic reasons. In the absence of evidence for head-to-head RCT direct comparison, the indirect comparison technique is an effective and resource-saving alternative. Matching-adjusted indirect comparison (MAIC) is an attractive method in the field of population-adjusted indirect comparisons between two trials. It can adjust for between-trial imbalances in the distribution of observed covariates by weighting the available individual patient data of the studied intervention and then match the aggregated data of the controlled intervention. Subsequently, the treatment effect comparison can be evaluated through the post-matched population. Although MAIC is gaining increasing attention in clinical research, especially in the evaluation of new drugs, efforts are still largely required for knowledge dissemination in China. In this paper, we briefly introduced the concepts, research value and examples, and pros and cons of MAIC.