Objective To explore the mechanisms of differentiation and development of pancreatic endocrine cells as well as pancreatic regeneration.Methods Human embryonic pancreatic tissue at 7-14 weeks of gestation was collecte...Objective To explore the mechanisms of differentiation and development of pancreatic endocrine cells as well as pancreatic regeneration.Methods Human embryonic pancreatic tissue at 7-14 weeks of gestation was collected.Diabetes mellitus rat model was induced with 65 mg/kg of streptozotocin.Insulin, glucagon, somatostatin, nestin, and cytokeratin 19 (CK19) of pancreatic tissues were observed by immunohistochemistry.Results At 9 weeks of gestation, pancreatic epithelial cells began to co-express insulin, glucagon, somatostatin, and CK19 before migration.Islet cells gradually congregated along with the increase of aging, and at 14 weeks of gestation histological examination showed islet formation.At 12 weeks of gestation, nestin-positive cells could be seen in the pancreatic mesenchyme.During early embryogenesis, islet cells of pancreatic ducts co-expressed insulin, glucagon, and somatostatin.During pancreatic regeneration after damage, nestin expression of islet cells increased.Conclusion In the early stage of embryogenesis, islet cells of primary pancreatic ducts can be differentiated to multipotential endocrine cells before migration.During tissue regeneration, pancreatic stem cells may differentiate and proliferate to form pancreatic islet.展开更多
Radiation therapy has been widely applied in cancer treatment.However,it often causes thrombocytopenia (deficiency of white blood cells) as an adverse effect.Recombinant human interleukin-6 (rhIL-6) has been found to ...Radiation therapy has been widely applied in cancer treatment.However,it often causes thrombocytopenia (deficiency of white blood cells) as an adverse effect.Recombinant human interleukin-6 (rhIL-6) has been found to be a very effective way against this thrombocytopenia,but IL-6 has low stability in blood,which reduces its efficacy.To increases the stability and half-life of rhIL-6,it was modified by polyethylene glycol (PEG).The pharmacokinetics and the tissue distribution of PEG-rhIL-6 labeled with 125I were examined after subcutaneous injection in rats.The pharmacokinetic pattern of PEG-rhIL-6 was defined with linear-kinetics,and we fitted a one-compartment model with half-lives of 10.44–11.37 h (absorption,t1/2Ka) and 19.77–21.53 h (elimination,t1/2Ke),and peak concentrations at 20.51–21.96 h (tpeak) in rats.Half-lives and tpeak of PEG-rhIL-6 were longer than those of rhIL-6 previously reported.In the present study,for deposition of PEG-rhIL-6 in rats,the tissue distribution examination showed that blood was the major organ involved,rather than liver.However,as to the elimination of PEG-rhIL-6,the major organ was the kidney.The excretion fraction of the injection dose recovered from urine was 23.32% at 192 h after subcutaneous administration.Less than 6% of PEG-rhIL-6 was eliminated via the feces at 192 h.These results indicate that PEG-rhIL-6 is a good candidate drug formulation for patients with cancer.展开更多
Objective： The effects of hydraulic pressure on renal tubular epithelial-myofibroblast transdifferentiation （TEMT） were investigated. Methods： We applied hydraulic pressure （50 cmH2O） to normal rat kidney tubula...Objective： The effects of hydraulic pressure on renal tubular epithelial-myofibroblast transdifferentiation （TEMT） were investigated. Methods： We applied hydraulic pressure （50 cmH2O） to normal rat kidney tubular epithelial cells （NRK52E） for different durations. Furthermore, different pressure magnitudes were applied to cells. The morphology, cytoskeleton, and expression ofmyofibroblastic marker protein and transforming growth factor-β1 （TGF-β1） of NRK52E cells were examined. Results Disorganized actin filaments and formation of curling clusters in actin were seen in the cytoplasm of pressurized cells. We verified that de novo expression α-smooth muscle actin induced by pressure, which indicated TEMT, was dependent on both the magnitude and duration of pressure. TGF-β1 expression was significantly upregulated under certain conditions, which implies that the induction of TEMT by hydraulic pressure is related with TGF-β1. Conclusion： We illustrate for the first time that hydraulic pressure can induce TEMT in a pressure magnitude- and duration-dependent manner, and that this TEMT is accompanied by TGF-β1 secretion.展开更多
文摘Objective To explore the mechanisms of differentiation and development of pancreatic endocrine cells as well as pancreatic regeneration.Methods Human embryonic pancreatic tissue at 7-14 weeks of gestation was collected.Diabetes mellitus rat model was induced with 65 mg/kg of streptozotocin.Insulin, glucagon, somatostatin, nestin, and cytokeratin 19 (CK19) of pancreatic tissues were observed by immunohistochemistry.Results At 9 weeks of gestation, pancreatic epithelial cells began to co-express insulin, glucagon, somatostatin, and CK19 before migration.Islet cells gradually congregated along with the increase of aging, and at 14 weeks of gestation histological examination showed islet formation.At 12 weeks of gestation, nestin-positive cells could be seen in the pancreatic mesenchyme.During early embryogenesis, islet cells of pancreatic ducts co-expressed insulin, glucagon, and somatostatin.During pancreatic regeneration after damage, nestin expression of islet cells increased.Conclusion In the early stage of embryogenesis, islet cells of primary pancreatic ducts can be differentiated to multipotential endocrine cells before migration.During tissue regeneration, pancreatic stem cells may differentiate and proliferate to form pancreatic islet.
基金Project (Nos.10802054 and 30700149) supported by the National Natural Science Foundation of China
文摘Radiation therapy has been widely applied in cancer treatment.However,it often causes thrombocytopenia (deficiency of white blood cells) as an adverse effect.Recombinant human interleukin-6 (rhIL-6) has been found to be a very effective way against this thrombocytopenia,but IL-6 has low stability in blood,which reduces its efficacy.To increases the stability and half-life of rhIL-6,it was modified by polyethylene glycol (PEG).The pharmacokinetics and the tissue distribution of PEG-rhIL-6 labeled with 125I were examined after subcutaneous injection in rats.The pharmacokinetic pattern of PEG-rhIL-6 was defined with linear-kinetics,and we fitted a one-compartment model with half-lives of 10.44–11.37 h (absorption,t1/2Ka) and 19.77–21.53 h (elimination,t1/2Ke),and peak concentrations at 20.51–21.96 h (tpeak) in rats.Half-lives and tpeak of PEG-rhIL-6 were longer than those of rhIL-6 previously reported.In the present study,for deposition of PEG-rhIL-6 in rats,the tissue distribution examination showed that blood was the major organ involved,rather than liver.However,as to the elimination of PEG-rhIL-6,the major organ was the kidney.The excretion fraction of the injection dose recovered from urine was 23.32% at 192 h after subcutaneous administration.Less than 6% of PEG-rhIL-6 was eliminated via the feces at 192 h.These results indicate that PEG-rhIL-6 is a good candidate drug formulation for patients with cancer.
基金Project (No. 2007CB947802) supported by National Basic Research Program of China
文摘Objective： The effects of hydraulic pressure on renal tubular epithelial-myofibroblast transdifferentiation （TEMT） were investigated. Methods： We applied hydraulic pressure （50 cmH2O） to normal rat kidney tubular epithelial cells （NRK52E） for different durations. Furthermore, different pressure magnitudes were applied to cells. The morphology, cytoskeleton, and expression ofmyofibroblastic marker protein and transforming growth factor-β1 （TGF-β1） of NRK52E cells were examined. Results Disorganized actin filaments and formation of curling clusters in actin were seen in the cytoplasm of pressurized cells. We verified that de novo expression α-smooth muscle actin induced by pressure, which indicated TEMT, was dependent on both the magnitude and duration of pressure. TGF-β1 expression was significantly upregulated under certain conditions, which implies that the induction of TEMT by hydraulic pressure is related with TGF-β1. Conclusion： We illustrate for the first time that hydraulic pressure can induce TEMT in a pressure magnitude- and duration-dependent manner, and that this TEMT is accompanied by TGF-β1 secretion.
