Does preoperative enteral or parenteral nutrition reduce postoperative complications in Crohn's disease patients: a meta-analysis.

OBJECTIVES: Crohn's disease (CD) patients frequently develop complications that require surgery for management. The high prevalence of malnutrition in CD patients presents a challenge because poor preoperative nutritional status has been shown to increase postoperative complications. In this study, we assessed whether preoperative enteral nutrition (EN) or total parenteral nutrition (TPN) decreases postoperative complications in CD patients. MATERIALS AND METHODS: A three-point systematic and comprehensive literature search was carried out on multiple databases followed by a meta-analysis with results presented as odds ratio (OR) using two models, the Mantel-Haenszel model and the DerSimonian and Laird model. The I measure of inconsistency was utilized to assess heterogeneity. If statistically significant heterogeneity was identified, the results underwent a separate sensitivity analysis. RESULTS: Five studies met inclusion criteria totaling 1111 CD patients. The rate of postoperative complications in the group receiving preoperative nutrition (EN or TPN) support was 20.0% compared with 61.3% in the group who had standard care without nutrition support [OR=0.26, 95% confidence interval (CI): 0.07-0.99, P<0.001]. Postoperative complications occurred in 15.0% of patients in the group who received preoperative TPN compared with 24.4% in the group who did not (OR=0.65, 95% CI: 0.23-1.88, P=0.43). Postoperative complications occurred in 21.9% in the group who received preoperative EN compared with 73.2% in the group that did not received preoperative EN (OR=0.09, 95% CI: 0.06-0.13, P<0.001). CONCLUSION: Preoperative nutrition supplementation reduces postoperative complications in CD patients. In particular, EN in CD patients before undergoing surgery is superior to standard of care without nutrition support with a number needed to treat of 2. There is a trend toward TPN being superior to standard of care without nutrition support, but this trend did not reach statistical significance. Further studies are necessary to evaluate specific components in EN or TPN that may be most beneficial for CD patients requiring surgical intervention.

Defining the nature of human pluripotent stem cell progeny.

While it is clear that human pluripotent stem cells (hPSCs) can differentiate to generate a panoply of various cell types, it is unknown how closely in vitro development mirrors that which occurs in vivo. To determine whether human embryonic stem cells (hESCs) and human-induced pluripotent stem cells (hiPSCs) make equivalent progeny, and whether either makes cells that are analogous to tissue-derived cells, we performed comprehensive transcriptome profiling of purified PSC derivatives and their tissue-derived counterparts. Expression profiling demonstrated that hESCs and hiPSCs make nearly identical progeny for the neural, hepatic, and mesenchymal lineages, and an absence of re-expression from exogenous reprogramming factors in hiPSC progeny. However, when compared to a tissue-derived counterpart, the progeny of both hESCs and hiPSCs maintained expression of a subset of genes normally associated with early mammalian development, regardless of the type of cell generated. While pluripotent genes (OCT4, SOX2, REX1, and NANOG) appeared to be silenced immediately upon differentiation from hPSCs, genes normally unique to early embryos (LIN28A, LIN28B, DPPA4, and others) were not fully silenced in hPSC derivatives. These data and evidence from expression patterns in early human fetal tissue (3-16 weeks of development) suggest that the differentiated progeny of hPSCs are reflective of very early human development (< 6 weeks). These findings provide support for the idea that hPSCs can serve as useful in vitro models of early human development, but also raise important issues for disease modeling and the clinical application of hPSC derivatives.