孕妇血清淀粉样蛋白A水平检测与早期原发性不明原因复发性流产的临床相关性研究

目的检测原发性不明原因早期复发性流产(recurrent early pregnancy loss,REPL)孕妇血清淀粉样蛋白A(serum amyloid A,SAA)水平,并探讨其对不明原因REPL的预测价值。方法将2014年1~12月间宝鸡市妇幼保健院妇产科收治的96例原发性不明原因REPL孕妇作为REPL组,并以96例无REPL史的正常孕妇作为对照组。采用酶联免疫法检测两组患者血清SAA水平,多因素Logistic回归分析REPL发病的危险因素,并采用ROC曲线评估SAA对REPL的诊断价值。结果 REPL组孕妇血清SAA中位浓度(50.0μg/ml)显著高于正常孕妇(11.6μg/ml)(Z=2.153,P=0.000<0.01)。SAA对REPL的诊断价值较高(AUC=0.91),最佳筛查阳性界值为18μg/ml。矫正孕妇年龄和孕周因素,SAA水平是原发性不明原因REPL发生的危险因素(OR值:1.12,P=0.000)。结论原发性不明原因REPL孕妇血清SAA水平升高可作为REPL发病的新的生物标志。

In vitro derivation of functional insulin-producing cells from human embryonic stem cells

The capacity for self-renewal and differentiation of human embryonic stem （ES） cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a newly developed and effective method, carried out in a serum-free system, which induced human ES cells to differentiate into insulin-producing cells. Activin A was used in the initial stage to induce definitive endoderm differentiation from human ES cells, as detected by the expression of the definitive endoderm markers Sox17 and Brachyury. Further, all-trans retinoic acid （RA） was used to promote pancreatic differentiation, as indicated by the expression of the early pancreatic transcription factors pdxl and hlxb9. After maturation in DMEM/F12 serum-free medium with bFGF and nicotinamide, the differentiated cells expressed islet specific markers such as C-peptide, insulin, glucagon and glut2. The percentage of C-peptide-positive cells exceeded 15%. The secretion of insulin and C-peptide by these cells corresponded to the variations in glucose levels. When transplanted into renal capsules of Streptozotocin （STZ）-treated nude mice, these differentiated human ES cells survived and maintained the expression of beta cell marker genes, including C-peptide, pdxl, glucokinase, nkx6.1, lAPP, pax6 and Tcfl. Thirty percent of the transplanted nude mice exhibited apparent restoration of stable euglycemia; and the corrected phenotype was sustained for more than six weeks. Our new method provides a promising in vitro differentiation model for studying the mechanisms of human pancreas development and illustrates the potential of using human ES cells for the treatment of type I diabetes mellitus.

Insulin-like growth factor binding protein-7 induces activation and transdifferentiation of hepatic stellate cells in vitro

AIM:To investigate the role of insulin-like growth factor binding protein-7 (IGFBP-7) in the activation and transdifferentiation of hepatic stellate cells (HSC) in vitro.METHODS:Rat HSC-T6 cells were cultured in separate dishes and treated with various concentration of transforming growth factor (TGF)-β1,IGFBP-7 or antiIGFBP-7 antibody for 24 h.The supernatant or a cytoplasm suspension was obtained from cultured HSC,followed by transfer of cells to form cell-coated dishes.Immunocytochemistry and Western blotting were used to analyze the expression of IGFBP-7 induced by TGF-β1 and the level of fibronectin,collagen and α-smooth muscle actin (SMA).The pro-apoptotic effect of antiIGFBP-7 antibody was determined by flow cytometry.RESULTS:Immunocytochemistry and Western blotting revealed that the expression of IGFBP-7 in TGF-β1 treated HSC was significantly up-regulated compared to that in the control group.In addition,fibronectin,collagen and α-SMA also showed enhanced expression in accordance with the transdifferentiation process in a dose-dependent manner to some extent.Moreover,flow cytometry suggested that anti-IGFBP-7 antibody induced apoptosis of activated HSC,which is responsible for the development of liver fibrosis,and may represent a novel pathway and target for therapeutic intervention.CONCLUSION:IGFBP-7 showed increased expression in activated HSC and played an important role in the activation and transdifferentiation process of HSC.AntiIGFBP-7 antibody may ameliorate liver fibrogenesis.

Repeated-batch Cultivation of Encapsulated Monascus purpureus by Polyelectrolyte Complex for Natural Pigment Production

In general,productions of natural pigment in submerged microorganism culture were much less than that in solid-state fermentation,because the solid-state culture can provide a support carrier for the mycelium. To improve natural pigment production,the cultivation of Monascus purpureus in submerged encapsulated cell was investigated. Monascus purpureus immobilized in polyelectrolyte complex(PEC) microcapsules,which were pre-pared by sodium cellulose sulphate(NaCS) and poly-dimethyl-diallyl-ammonium chloride(PDMDAAC),was a good substitute for submerged cell culture because it mimicked the solid-state environment. The repeated-batch process with encapsulated cells was studied in flasks and a bubble column. The results indicated that the bubble column was more suitable for the encapsulation culture than the shaking flasks because of its good mass transfer performance and minor shear stress on cells. Owing to the protection of the microcapsule's membrane,Monascus purpureus in microcapsules increased approximately three times over that in free cell culture with negligible cell leakage to the medium. The pigment production in the bubble column finally reached 3.82(OD500) ,which was two times higher than in free cell culture. In addition,the duration of each batch was shortened to 15% of that in free cell culture.

Extracellular green synthesis of silver nanoparticles using Amazonian fruit Araza(Eugenia stipitata McVaugh)

An eco-friendly method for the extracellular synthesis of silver nanoparticles（AgNPs） using aqueous Araza fruit extract and their antioxidant activity was investigated. It was observed that UV–Vis absorption peak is dependent on various parameters such as pH, temperature, and change of time. The initial appearance of the yellow color with intense surface plasmon bands at 430-450 nm, then transmission electron microscopy, scanning electron microscopy and X-ray diffraction analysis revealed the formation of 15-45 nm sized, spherical and crystalline Ag NPs. Fourier transform infrared spectroscopy depicted that malic acid, citric acid, and carotenoids of Araza fruit involved in the synthesis of Ag NPs. In addition, the surface modified AgNPs（77.42%, 1mL） showed nearly double antioxidant efficiency than Araza fruit extract（35.30%, 1 mL） against 1, 1-diphenyl-2-picrylhydrazyl. The present study highlights the possibility of using the Araza fruit to synthesize AgNPs, which could be used effectively in the present and future antioxidant agent.

IDENTIFICATION OF SPECIFIC PEPTIDE LIGANDS FOR B-LYMPHOMA CELL AND ITS EFFECT ON TYROSINE PHOSPHORYLATION AND CELL APOPTOSIS

Objective To search novel method for diagnosis and therapy of B-lymphoma, specific small mo-lecular peptide ligands against binding site of tumor cells were screened and its effects on signal transduction and cell apoptosis were tested. Methods Specific peptide ligands were screened by binding with site of human B lymphoma cell(OC1LY8)using peptide-bead libraries. The identified peptides were characterized with responsible cellsby rebinding test. The role of tyrosine phosphorylation of peptide ligand was tested by Western blot; and its apoptosispromoting role was observed by confocal fluorescent microscope. Results Specific peptide ligand was able to bind specifically to site on cell surface and enter into cytoplasm. Tetrameric peptide ligand was able to strongly trigger signal transduction resulting in tyrosine phosphorylation and cellular apoptosis in OC1LY8 cell line. Conclusion Screened peptide ligand can effectively bind with OC1LY8 cell, stimulate cellular tyro-sine phosphorylation and induce cellular apoptosis.