Activated PSCs are present in the stromal reaction in pancreatic cancers and are responsible for the production of stromal collagen. PSC function is influenced by pancreatic cancer cells. Interactions between tumor cells and stromal cells (PSCs) may play an important role in the pathobiology of pancreatic cancer.
The mechanisms of pancreatic fibrosis are poorly understood. In the liver, stellate cells play an important role in fibrogenesis. Similar cells have recently been isolated from the pancreas and are termed pancreatic stellate cells. The aim of this study was to determine whether pancreatic stellate cell activation occurs during experimental and human pancreatic fibrosis. Pancreatic fibrosis was induced in rats (n = 24) by infusion of trinitrobenzene sulfonic acid (TNBS) into the pancreatic duct. Surgical specimens were obtained from patients with chronic pancreatitis (n = 6). Pancreatic fibrosis was assessed using the Sirius Red stain and immunohistochemistry for collagen type I. Pancreatic stellate cell activation was assessed by staining for alpha-smooth muscle actin (alphaSMA), desmin, and platelet-derived growth factor receptor type beta (PDGFRbeta). The relationship of fibrosis to stellate cell activation was studied by staining of serial sections for alphaSMA, desmin, PDGFRbeta, and collagen, and by dual-staining for alphaSMA plus either Sirius Red or in situ hybridization for procollagen alpha(1) (I) mRNA. The cellular source of TGFbeta was examined by immunohistochemistry. The histological appearances in the TNBS model resembled those found in human chronic pancreatitis. Areas of pancreatic fibrosis stained positively for Sirius Red and collagen type I. Sirius Red staining was associated with alphaSMA-positive cells. alphaSMA staining colocalized with procollagen alpha(1) (I) mRNA expression. In the rat model, desmin staining was associated with PDGFRbeta in areas of fibrosis. TGFbeta was maximal in acinar cells adjacent to areas of fibrosis and spindle cells within fibrotic bands. Pancreatic stellate cell activation is associated with fibrosis in both human pancreas and in an animal model. These cells appear to play an important role in pancreatic fibrogenesis.
OBJECTIVETransplantation of insulin-producing cells placed inside microcapsules is being trialled to overcome the need for immunosuppressive therapy.RESEARCH DESIGN AND METHODSFour type 1 diabetic patients with no detectable C-peptide received an intraperitoneal infusion of islets inside microcapsules of barium alginate (mean 178,200 islet equivalents on each of eight occasions).RESULTSC-peptide was detected on day 1 post-transplantation, and blood glucose levels and insulin requirements decreased. C-peptide was undetectable by 1–4 weeks. In a multi-islet recipient, C-peptide was detected at 6 weeks after the third infusion and remains detectable at 2.5 years. Neither insulin requirements nor glycemic control was affected. Capsules recovered at 16 months were surrounded by fibrous tissue and contained necrotic islets. No major side effects or infection occurred.CONCLUSIONSWhile allografting of encapsulated human islets is safe, efficacy of the cells needs to improve for the therapy to make an impact on the clinical scene.
The Confederation of Postgraduate Medical Education Councils launched the Australian Curriculum Framework for Junior Doctors in October 2006.
The curriculum framework:
balances the major areas of clinical management, communication and professionalism, and highlights the importance of an integrated approach to prevocational learning and teaching;
supports practice‐based, opportunistic and continuous learning, and specifies performance and supervision requirements for junior doctors; and
has been published in both Internet and printable versions, to make the document accessible and easily usable by junior doctors and supervisors.
The implementation of the curriculum framework will be overseen by a steering group that includes representatives from key stakeholder groups, including junior doctors and medical students.
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