Long-term survival outcomes of laparoscopic versus open gastrectomy for gastric cancer: a systematic review and meta-analysis.

Many meta-analyses have confirmed the technical feasibility and favorable short-term surgical outcomes of laparoscopic gastrectomy (LG) for gastric cancer patients, but the long-term survival outcome of LG remains controversial compared with open gastrectomy (OG). This study aimed to compare the 5-year overall survival (OS), recurrence, and gastric cancer-related death of LG with OG among gastric cancer patients. PubMed was searched to February 2014. The resectable gastric cancer patients who underwent curative LG or OG were eligible. The studies that compared 5-year OS, recurrence, or gastric cancer-related death in the LG and OG groups were included. A meta-analysis, meta-regression, sensitivity analysis, subgroup analysis, and stage-specific analysis were performed to estimate the survival outcome between the two groups and identify the potential confounders. Quality assessment was based on a tailored comparability scoring system. Twenty-three studies with 7336 patients were included. The score of comparability between two groups and the extent of lymphadenectomy were two independent confounders. Based on the well-balanced studies, the 5-year OS (OR = 1.07, 95% CI 0.90-1.28, P = 0.45), recurrence (OR = 0.83, 95% CI 0.68-1.02, P = 0.08), and gastric cancer-related death (OR = 0.86, 95% CI 0.65-1.13, P = 0.28) rates were comparable in LG and OG. Several subsets such as the publication year, study region, sample size, gastrectomy pattern, extent of lymphadenectomy, number of nodes harvested, and proportion of T1-2 or N0-1 did not influence the estimates, if they were well balanced. Particularly, the stage-specific estimates obtained comparable results between the two groups. Randomized controlled trials comparing LG with OG remain sparse to assess their long-term survival outcomes. The major contributions of this systematic review compared with other meta-analyses are a comprehensive collection of available long-term survival outcomes within a much larger number of observations and a more precise consideration of confounders. Current knowledge indicates that the long-term survival outcome of laparoscopic gastric cancer surgery is comparable to that of open surgery among early or advanced stage gastric cancer patients, and LG is acceptable with regard to oncologic safety.

Osteogenic differentiation of bone mesenchymal stem cells regulated by osteoblasts under EMF exposure in a co-culture system.

This study examined the osteogenic effect of electromagnetic fields (EMF) under the simulated in vivo conditions. Rat bone marrow mesenchymal stem cells (BMSCs) and rat osteoblasts were co-cultured and exposed to 50 Hz, 1.0 mT EMF for different terms. Unexposed single-cultured BMSCs and osteoblasts were set as controls. Cell proliferation features of single-cultured BMSCs and osteoblasts were studied by using a cell counting kit (CCK-8). For the co-culture system, cells in each group were randomly chosen for alkaline phosphatase (ALP) staining on the day 7. When EMF exposure lasted for 14 days, dishes in each group were randomly chosen for total RNA extraction and von Kossa staining. The mRNA expression of osteogenic markers was detected by using real-time PCR. Our study showed that short-term EMF exposure (2 h/day) could obviously promote proliferation of BMSCs and osteoblasts, while long-term EMF (8 h/day) could promote osteogenic differentiation significantly under co-cultured conditions. Under EMF exposure, osteogenesis-related mRNA expression changed obviously in co-cultured and single-cultured cells. It was noteworthy that most osteogenic indices in osteoblasts were increased markedly after co-culture except Bmp2, which was increased gradually when cells were exposed to EMF. Compared to other indices, the expression of Bmp2 in BMSCs was increased sharply in both single-cultured and co-cultured groups when they were exposed to EMF. The mRNA expression of Bmp2 in BMSCs was approximately four times higher in 8-h EMF group than that in the unexposed group. Our results suggest that Bmp2-mediated cellular interaction induced by EMF exposure might play an important role in the osteogenic differentiation of BMSCs.

Effect of umbilical cord mesenchymal stem cells on treatment of severe acute pancreatitis in rats.

BACKGROUND AIMS: The aim of this study was to investigate the effect of umbilical cord mesenchymal stem cells (UCMSCs) on severe acute pancreatitis (SAP) in rats. METHODS: SAP was established in rats by retrograde pancreatic duct injection of sodium taurocholate. In one group, 5 × 10(6) cells/kg of UCMSC suspension was injected into the tail vein 0 h, 1 h, 6 h and 12 h after the induction of SAP. In other groups, different doses of UCMSC suspension (5 × 10(4) cells/kg, 5 × 10(5) cells/kg, 5 × 10(6) cells/kg or 1 × 10(7) cells/kg) were administered at 1 h. Serum amylase was assayed at 12 h. Mortality, ascites, serum tumor necrosis factor-α, interferon-γ (assayed using enzyme-linked immunosorbent assay) and the wet-dry weight of the pancreas gland were assessed at 48 h. Pathologic changes of pancreatic and pulmonary tissues were observed. RESULTS: Mortality in rats receiving 5 × 10(6) cells/kg of UCMSCs at 0 h was 10% compared with 58% in the SAP control group. Ascites, serum amylase and wet-dry pancreatic weight significantly decreased, and production of tumor necrosis factor-α and interferon-γ were reduced. Pathologic injuries of pancreatic and pulmonary tissues were markedly alleviated. Administration of UCMSCs (5 × 10(5) cells/kg, 5 × 10(6) cells/kg or 1 × 10(7) cells/kg) at 1 h or 5 × 10(6) cells/kg at 6 h significantly reduced the severity of SAP. The effect was less marked at 12 h and with lower concentrations of UCMSCs. CONCLUSIONS: UCMSCs significantly decreased pancreatic injury caused by SAP in a time-dependent and dose-dependent way.