Liang Liang

This study examined the effects of mechanical strain on osteogenic and adipogenic differentiation of cultured MSCs by stimulating MSCs cultured in general and adipogenic differentiation media using a mechanical strain device. Markers of osteogenic (Runx2, Osx, and I-collagen) and adipogenic (PPARγ-2, C/EBPα, and lipid droplets) differentiation were examined using real-time PCR, western blot, immunocytochemical, or histochemical stain analyses. Levels of Runx2 and Osx gradually increased in MSC groups in general medium subject to strain stimulation, as compared with in unstrained groups. After adding the stress signal, I-collagen protein levels of expression were obviously promoted in cells in comparison to the controls. The levels of PPARγ-2 and C/EBPα were decreased, and the emergence of lipid droplets was delayed in MSCs groups in adipogenic differentiation medium subject to strain stimulation, as compared with in unstrained groups. Mechanical strain can promote differentiation of MSCs into osteoblasts and can impede differentiation into adipocytes. These results clarify the mechanisms underlying the effects of exercise on bone repair and reconstruction and provide a more adequate scientific basis for the use of exercise therapy in the treatment of obesity and metabolic osteoporosis.

BACKGROUND: Intraoperative blood salvage (IBS) reduces homologous transfusion in orthotopic liver transplantation (OLT), but may carry with it the risk of reinfusing tumor cells in patients with hepatocellular carcinoma (HCC). The use of leukocyte depletion filters (LDFs) for the removal of tumor cells is rarely reported in clinical OLT. The aims of this study were to evaluate the frequency of tumor cell contamination in surgical field during OLT for HCC recipients and to investigate the efficiency of additional LDFs for eliminating tumor cells from IBS. METHODS: Thirty-two HCC patients with preoperatively elevated serum alpha-fetoprotein (AFP) underwent OLT. The blood from the surgical field was collected and processed by an autotransfusion device (Cell Saver 5), followed by 2 consecutive LDF filtrations. The HCC cells in IBS samples and filtered samples were determined using a nested RT-PCR technique to detect the AFP mRNA. RESULTS: The shed blood samples from 20 (62.5%) of the 32 HCC patients were contaminated with HCC cells and 15 of them remained positive after Cell Saver processing. Patients within the Milan or UCSF criteria were less likely to have HCC cell contamination and the contaminated HCC cells were more likely to be removed by the Cell Saver in these patients as compared to other patients (P<0.01). After filtration through an additional LDF, most cases (13/15) became negative except for those with ruptured tumors (P<0.05). CONCLUSIONS: Our results suggest that blood filtration with the LDF can efficiently remove tumor cells and the use of an additional LDF after use of the Cell Saver could markedly reduce the risk of tumor cell reintroduction during the OLT in HCC recipients with nonruptured tumors.

BACKGROUND: Many of the acute alterations after peroral endoscopic myotomy (POEM) may be of little clinical significance, while others may herald major clinical problems. The question whether pneumomediastinum/pneumoperitoneum is a normal postoperative finding after POEM, or should be regarded as a sign of a complication needs to be evaluated. Familiarity with these findings in computed tomography (CT) is essential for radiologists. PURPOSE: To evaluate whether or not pneumomediastinum/pneumoperitoneum detected by chest CT is a sign of a complication after POEM using CO2 insufflation for esophageal achalasia. MATERIAL AND METHODS: One hundred and eight patients with esophageal achalasia who underwent chest CT within 30 hours after POEM were included. CT findings were retrospectively reviewed by two radiologists in consensus. The correlation between pneumomediastinum and/or pneumoperitoneum shown on CT and the development of complications was analyzed. RESULTS: Abnormal findings were identified on post-treatment CT, including pneumomediastinum and/or pneumoperitoneum (53.7%, 58/108), pneumothorax (0.9%, 1/108), subcutaneous emphysema (29.6%, 32/108), pleural effusion (69.4%, 75/108), segmental atelectasis of lung tissue (29.6%, 32/108), minor inflammation of lungs (69.4%, 75/108), and ascites (0.9%, 1/108). Pneumomediastinum and pneumoperitoneum were observed simultaneously in 29 cases. The incidence rate of mild complications was high (79.6%, 86/108), while the rate of severe complications was low (2.8%, 3/108). There was no significant correlation between the occurrence of pneumomediastinum and/or pneumoperitoneum on CT and the development of complications (P = 0.542), or the development of severe complications including delayed hemorrhage, esophageal perforation, and retroperitoneal abscess. CONCLUSION: Pneumomediastinum and pneumoperitoneum detected by CT occur frequently after POEM and may be regarded as normal postoperative changes.