【Abstract】ObjectiveTo study Toll like receptor 4 (TLR4) expression on peripheral blood monocytes (PBMCs) during the early stage of human acute pancreatitis. MethodsThirty consecutive patients with acute pancreatitis admitted within 24 h of onset of abdominal pain were enrolled in this study. Another 20 healthy volunteers were included as control. Blood samples were collected by venipuncture on the day of admission and 3， 7 d after admission and PBMCs were isolated. TLR4 and CD14 expressions on PBMCs were detected by flow cytometry. Serum tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) were measured simultaneously. Correlations between these parameters were analyzed. ResultsTLR4 expression increased on the day of admission and then continued to decline for several days. On third day, TLR4 expression was almost normal compared with the normal control. The alteration of serum TNF-α was consistent with that of TLR4. ConclusionDuring the early stage of human acute pancreatitis, mononuclear-macrophages may be ignited through TLR4 (a door keeper of innate immune system), which lead to TNF-α production.
Objective To discuss the role of heparan sulfate (HS) in bone formation and bone remodeling and summarize the research progress in the osteogenic mechanism of HS. Methods The domestic and abroad related literature about HS acting on osteoblast cell line in vitro, HS and HS composite scaffold materials acting on the ani-mal bone defect models, and the effect of HS proteoglycans on bone development were summarized and analyzed. Results Many growth factors involved in fracture healing especially heparin-binding growth factors, such as fibroblast growth factors, bone morphogenetic protein, and transforming growth factor β, are connected noncovalently with long HS chains. HS proteoglycans protect these proteins from protease degradation and are directly involved in the regulation of growth factors signaling and bone cell function. HS can promote the differentiation of stem cells into osteoblasts and enhance the differentiation of osteoblasts. In bone matrix, HS plays a significant role in promoting the formation, maintaining the stability, and accelerating the mineralization. Conclusion The osteogenesis of HS is pronounced. HS is likely to become the clinical treatment measures of fracture nonunion or delayed union, and is expected to provide more choices for bone tissue engineering with identification of its long-term safety.