Zhao-Feng Tang

Hedgehog-mediated paracrine interaction between hepatic stellate cells and marrow-derived mesenchymal stem cells

During liver injury, bone marrow-derived mesenchymal stem cells (MSCs) can migrate and differentiate into hepatocytes. Hepatic stellate cell (SC) activation is a pivotal event in the development of liver fibrosis. Therefore, we hypothesized that SCs may play an important role in regulating MSC proliferation and differentiation through the paracrine signaling pathway. We demonstrate that MSCs and SCs both express hedgehog (Hh) pathway components, including its ligands, receptors, and target genes. Transwell co-cultures of SCs and MSCs showed that the SCs produced sonic hedgehog (Shh), which enhanced the proliferation and differentiation of MSCs. These findings demonstrate that SCs indirectly modulate the activity of MSCs in vitro via the Hh pathway, and provide a plausible explanation for the mechanisms of transplanted MSCs in the treatment of liver fibrosis.

Experimental study of pancreaticojejunostomy completed using anastomotic chains

The most difficult, time-consuming, and complication-prone step in pancreaticoduodenectomy is the pancreaticojejunostomy step. The largest disadvantage of this kind of anastomosis is the high incidence of postoperative anastomotic leakage. Once pancreatic leakage occurs, the patient death rate can be very high. The aim of this study was to design a pancreaticojejunostomy procedure using anastomotic chains, which results in the cut end of the jejunum being attached to the pancreatic stump without suturing, and to evaluate the safety and efficacy of this procedure in domestic pigs. The pancreaticojejunal anastomotic chains had the following structures: the chains consisted of two braceletlike chains made of titanium, named chain A and chain B. The function of chain A was to attach the free jejunal end onto the pancreatic stump, whereas the function of chain B was to tighten the contact between the jejunal wall and the surface of the pancreatic stump to eliminate gaps between the two structures and ensure tightness that is sufficient to guarantee that there is no leakage of jejunal fluid or pancreatic juice. The following procedure was used to assess the safety and efficacy of the procedure: pancreaticojejunostomies were performed on ten domestic pigs using anastomotic chains. The time required to complete the pancreaticojejunal anastomoses, the pressure tolerance of the pancreaticojejunal anastomoses, the pig death rate, and the histopathological examinations of the pancreaticojejunostomy tissues were recorded. The average time required to complete the pancreaticojejunal anastomosis procedure was 13+/-2 min. The observed tolerance pressure of the pancreaticojejunal anastomoses was more than 90 mm H(2)O. All ten domestic pigs that underwent operations were still alive four weeks after the operations. Pathological examinations showed that the anastomotic surfaces were completely healed, and the pancreatic cutting surfaces were primarily epithelialized. In conclusion, the use of anastomotic chains in pancreaticojejunostomy procedures results in a decrease in or elimination of pancreatic leakage. In addition, the procedure is simple to perform, is not time-intensive, and appears to be safe in a pig model.