Endoscopic transpapillary pancreatic stenting for internal pancreatic fistula with the disruption of the pancreatic ductal system

BackgroundInternal pancreatic fistula (IPF) is a well-recognized complication of pancreatic diseases. Although there have been many reports concerning IPF, the therapy for IPF still remains controversial. We herein report our experiences with endoscopic transpapillary pancreatic stent therapy for IPF and evaluate its validity.MethodSix patients with IPF who presented at our department and received endoscopic transpapillary pancreatic stent therapy were investigated, focusing on the clinical and imaging features as well as treatment strategies, the response to therapy and the outcome.ResultsAll patients were complicated with stenosis or obstruction of the main pancreatic duct, and in these cases the pancreatic ductal disruption developed distal to the areas of pancreatic stricture. The sites of pancreatic ductal disruption were the pancreatic body in five patients and the pancreatic tail in one patient. All patients received endoscopic stent placement over the stenosis site of the pancreatic duct. Three patients improved completely and one patient improved temporarily. Finally, three patients underwent surgical treatment for IPF. All patients have maintained a good course without a recurrence of IPF.ConclusionEndoscopic transpapillary pancreatic stent therapy may be an appropriate first-line treatment to be considered before surgical treatment. The point of stenting for IPF is to place a stent over the stenosis site of the pancreatic duct to reduce the pancreatic ductal pressure and the pseudocyst's pressure.     

Development of a novel rat model with pancreatic fistula and the prevention of this complication using tissue-engineered myoblast sheets

Background

Pancreatic fistula (PF) is one of the most important complications of pancreatic surgery. The aims of this study were to establish a PF model in rats and to investigate the efficacy of our new method for preventing PF, which utilizes myoblast sheets made using tissue engineering techniques.

Methods

To establish a PF model, the rats underwent transection of each of four pancreatic ducts: the gastric, duodenal, common, and splenic ducts, respectively. Their ascitic amylase and lipase levels were then measured. To investigate the efficacy of myoblast sheets at preventing PF, a myoblast sheet was attached to the pancreatic stump in the PF models. The levels of amylase and lipase in both serum and ascites were then measured, and surgical specimens were investigated pathologically.

Results

The new PF model established by transecting the splenic duct in rats may prove very useful. There were no significant differences in serum amylase and lipase levels between the myoblast sheet (+) group and the sheet (?) group. However, there were significant differences in ascitic amylase and lipase levels between the two groups (p < 0.05). Among the pathological findings, the number of inflammatory cells in the myoblast sheet group was smaller than that in the control group. In addition, the presence of the myoblast sheets on the surface of the pancreatic stump was confirmed by immunofluorescence staining.

Conclusion

Our data demonstrate the efficacy of the new rat model of PF presented herein, and that it might be possible to prevent PF using myoblast sheets.     

Excessive exposure to anionic surfaces maintains autoantibody response to beta(2)-glycoprotein I in patients with antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an autoimmune prothrombotic disorder associated with autoantibodies to phospholipid (PL)-binding proteins, such as beta(2)-glycoprotein I (beta(2)GPI). We have recently reported that binding of beta(2)GPI to anionic PL facilitates processing and presentation of the cryptic beta(2)GPI epitope that activates pathogenic autoreactive T cells. To clarify mechanisms that induce sustained presentation of the dominant antigenic beta(2)GPI determinant in patients with APS, T-cell proliferation induced by beta(2)GPI-treated phosphatidylserine liposome (beta(2)GPI/PS) was evaluated in bulk peripheral blood mononuclear cell cultures. T cells from patients with APS responded to beta(2)GPI/PS in the presence of immunoglobulin G (IgG) anti-beta(2)GPI antibodies derived from APS plasma, and this response was completely inhibited either by the depletion of monocytes or by the addition of anti-FcgammaRI antibody. These findings indicate that efficient presentation of the cryptic determinants can be achieved by monocytes undergoing FcgammaRI-mediated uptake of beta(2)GPI-bound anionic surfaces in the presence of IgG anti-beta(2)GPI antibodies. Finally, beta(2)GPI-bound oxidized LDL or activated platelets also induced the specific T-cell response. Continuous exposure to these anionic surfaces may play a critical role in maintaining the pathogenic anti-beta(2)GPI antibody response in patients with APS.     

Transplantation of meniscus regenerated by tissue engineering with a scaffold derived from a rat meniscus and mesenchymal stromal cells derived from rat bone marrow

Abstract:  The purpose of this study was to assess transplantation of regenerated menisci using scaffolds from normal allogeneic menisci and bone-marrow-derived mesenchymal stromal cells (BM-MSCs) of rats. We reported that scaffolds derived from normal menisci seeded with BM-MSCs in vitro could form meniscal tissues within 4 weeks. Then, we hypothesized that our tissues could be more beneficial than allogeneic menisci regarding early maturation and chondroprotective effect. Bone marrow was aspirated from enhanced green fluorescent protein transgenic rats. BM-MSCs were isolated and seeded onto scaffolds which were prepared from Sprague–Dawley rat menisci. After 4 weeks in coculture, the tissues were transplanted to the defect of menisci. Repopulation of BM-MSCs and expression of extracellular matrices were observed in the transplanted tissues at 4 weeks after surgery. At 8 weeks, articular cartilage in the cell-free group was more damaged compared to that in the cell-seeded group or the meniscectomy group.     

Osteogenesis Depending on Geometry of Porous Hydroxyapatite Scaffolds

The effect of the configuration of porous cylindrical hydroxyapatite (HA) scaffold and laminin preparation of the scaffold on bone formation was estimated. HA scaffolds with a hollow center of 2 or 4 mm in diameter and those without a hollow center were used. The scaffolds were immersed in laminin solution or in culture medium. Bone marrow cells were obtained from the femora of male Fischer 344 rats. Cell suspension was prepared at 1 x 10(6) cells/mL density. The cells were seeded into HA scaffolds. Each scaffold was implanted in the dorsal subcutis of rats for 4 weeks. Bone formation in scaffolds was observed histologically. The quantity of osteocalcin was measured immunochemically. Many pores containing bone were identified in the laminin-immersed HA scaffold with a hollow center measuring 4 mm in diameter than those without and those with a hollow center measuring 2 mm in diameter. A greater quantity of osteocalcin was detected in the HA scaffold with immersion in laminin than in that without immersion in laminin. However, the results of the immunochemical assay for osteocalcin showed that a hollow center in the scaffold did not contribute to bone formation compared to scaffolds without a hollow center. It is considered that laminin may act as an adhesive for effective cell attachment to the walls of the pores in an HA scaffold.