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.

Severe traumatic dislocation of the lower cervical spine with mild neurological symptoms: Case reports and literature review.

CONTEXT: Severe traumatic fractures and dislocations of the lower cervical spine are usually accompanied by irreversible spinal cord injuries. Such patients rarely have mild or no neurological symptoms. FINDINGS: We report three cases of severe lower cervical dislocation without spinal cord injury and discuss the mechanisms underlying this type of injury. All three patients had severe lower cervical dislocation, but their neurological symptoms were mild. In all cases, the fractures occurred at the bilateral junctions of the lamina and pedicle, resulting in severe cervical spondylolisthesis, whereas the posterior structure remained in place, thereby increasing the cross-sectional area of the spinal canal. After preoperative skull traction for a few days, the patients underwent anterior or combined anterior and posterior cervical surgeries. All surgeries were successfully completed and the patient's symptoms disappeared at the last follow-up. CONCLUSION: Severe traumatic dislocation of the lower cervical spine with an intact neurological status is rare in clinical practice. Pathological canal enlargement preserves neurological function, and the most commonly injured segment is C7. Preoperative traction for closed reduction remains controversial. We suggest that if no obvious anterior compression is observed, closed reduction should be pursued. Anterior or combined anterior and posterior cervical surgeries can provide rigid fixation with satisfactory results.

Efficacy of linaclotide in combination with polyethylene glycol for bowel preparation in Chinese patients undergoing colonoscopy polypectomy: protocol for a randomised controlled trial.

BACKGROUND: Adequate bowel preparation is essential for successful colonoscopy and polypectomy procedures. However, a significant proportion of patients still exhibit suboptimal bowel preparation, ranging from 18% to 35%. The effectiveness of bowel preparation agents can be hampered by volume and taste, adversely affecting patient compliance and tolerance. Therefore, exploring strategies to minimise laxative volume and improve patient tolerance and adherence is imperative to ensure optimal bowel preparation quality. METHODS AND ANALYSIS: This study is a two-arm, single-blinded, parallel-group randomised controlled trial designed to compare the efficacy of 2 L polyethylene glycol (PEG) combined with linaclotide with 4 L PEG in bowel cleansing. A total of 422 participants will be randomly assigned in a 1:1 ratio to either the intervention group (2 L PEG combined with 580 µg linaclotide) or the control group (4 L PEG). The primary outcome measure is bowel cleansing efficacy, which is assessed using the Boston Bowel Preparation Scale. Secondary outcomes include evaluating the tolerability and safety of the bowel preparation regimens, bowel diary assessments, postpolypectomy complications (such as bleeding and perforation) and the size and number of removed polyps. ETHICS AND DISSEMINATION: The study has received approval from the Clinical Research Ethics Committee of The First Affiliated Hospital, Zhejiang University School of Medicine. The findings of this trial will serve as a valuable resource for clinicians and patients undergoing colonoscopy polypectomy by guiding the selection of appropriate bowel preparation regimens. Study findings will be disseminated to participants, presented at professional society meetings, and published in peer-reviewed journals. This trial was registered on the Chinese Clinical Trial Registry with registration number ChiCTR2300075410.

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.

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.