胶原基生物膜材料的制备与应用

纯化的胶原经过改性或共混 ,可制得有优良生物特性的膜成品。胶原基生物膜材料的应用非常广泛 ,可作为药物输送系统、基因传送载体、可钙化基质系统、组织培养支架、角膜保护膜。

正常大鼠颌下腺上皮细胞极性培养

目的为了探索简便、有效的涎腺上皮细胞的体外培养方法。方法采用自制鼠尾胶原胶为底物．在培养液中加入一些促进上皮细胞生长分化的刺激物，对出生一天的Wistar大鼠颌下腺上皮细胞进行原代培养。通过相差显微微镜、光镜及透射电镜对上皮细胞的生长及分化进行观察和研究。结果培养的大鼠颌下腺上皮细胞呈多层生长且为极性分化，保留了腺泡导管分泌单位的三种上皮成份。结论本研究所采用的方法是一种简便、可行、有效的涎腺上皮细胞的体外培养方法，其中自制胶原胶是本研究培养成功的关键。

老年2型糖尿病患者空腹C肽、25-羟基维生素D水平与骨密度的关系研究

目的研究老年2型糖尿病患者骨密度与空腹C肽、25-羟基维生素D水平的相关性。方法选取2018年5月—2019年5月收治的老年2型糖尿病132例作为老年2型糖尿病组,其中骨量正常组50例,骨量减少组42例,骨质疏松组40例;另外选取同期行健康体检的正常老年人50例作为健康对照组。检测所有受试者骨密度及血清空腹C肽、25-羟基维生素D水平,分析空腹C肽、25-羟基维生素D、临床生化指标与骨密度的关系,以及空腹C肽、25-羟基维生素D、骨密度的相关性。结果老年2型糖尿病组骨密度、空腹C肽、25-羟基维生素D水平低于健康对照组(P<0.05)。骨量减少组、骨质疏松组空腹C肽、25-羟基维生素D水平低于骨量正常组,且骨质疏松组低于骨量减少组(P<0.05)。骨量减少组、骨质疏松组血清钙、血磷、骨钙素(BGP)水平低于骨量正常组,24 h尿蛋白定量、糖化血红蛋白、Ⅰ型胶原胶联蛋白羧基末端肽(CTX-Ⅰ)水平高于骨量正常组(P<0.05);骨质疏松组血清钙、血磷、BGP水平低于骨量减少组,24 h尿蛋白定量、糖化血红蛋白、CTX-Ⅰ水平高于骨量减少组(P<0.05)。骨密度与空腹C肽呈正相关(r=0.304,P=0.007);骨密度与25-羟基维生素D呈正相关(r=0.198,P=0.023);空腹C肽与25-羟基维生素D呈正相关(r=0.397,P=0.001)。结论老年2型糖尿病患者骨密度与空腹C肽、25-羟基维生素D相关,且与骨代谢指标水平有关。

Vascular Channel Formation by Osteosarcoma Cells in Vitro: Vasculogenic Mimicry

Objective: To observe whether there is evidence for vascular channel formation by osteosarcoma cellsin vitro and to illustrate mechanism of vasculogenic mimicry in osteosarcoma.Methods: Osteosarcoma cell lines (U-2OS) were tested for their ability to form tubular networks in three-dimensional culture containing type I collagen. The structures of the tubular networks were observed under a phase contrast microscope and an electron microscope.Results: Observation under light microscopy and electron microscopy showed that high aggressive osteosarcoma cells line (U-2OS) formed networks containing channels when grown in three-dimensional culture containing type I collagen in the absence of endothelial cells or fibroblasts.Conclusion: These observations strongly suggest that aggressive osteosarcoma cells may generate vascular channels that facilitate tumor perfusion independent of tumor angiogenesis and have the ability of vasculogenic mimicry. Key words osteosarcoma cells line - vasculogenesis mimicry - angiogenesis - 3-dimensional cultures This study was supported in part by the National Natural Sciences Foundation of China (No. 30271314).

Effects of P2Y_1 receptor on glial fibrillary acidic protein and glial cell line-derived neurotrophic factor production of astrocytes under ischemic condition and the related signaling pathways

Objective The present study aimed to explore the role of P2Y1 receptor in glial fibrillary acidic protein （GFAP） production and glial cell line-derived neurotrophic factor （GDNF） secretion of astrocytes under ischemic insult and the related signaling pathways. Methods Using transient right middle cerebral artery occlusion （tMCAO） and oxygen-glucose-serum deprivation for 2 h as the model of ischemic injury in vivo and in vitro, immunofluorescence, quantitative real-time reverse transcription-polymerase chain reaction （RT-PCR）, Western blotting, enzyme linked immunosorbent assay （ELISA） were used to investigate location of P2Y1 receptor and GDNF, the expression of GFAP and GDNF, and the changes of signaling molecules. Results Blockage of P2Y1 receptor with the selective antagonist N^6-methyl-2′-deoxyadenosine 3′,5′-bisphosphate diammonium （MRS2179） reduced GFAP production and increased GDNF production in the antagonist group as compared with simple ischemic group both in vivo and in vitro. Oxygen-glucose-serum deprivation and blockage of P2Y1 receptor caused elevation of phosphorylated Akt and cAMP response element binding protein （CREB）, and reduction of phosphorylated Janus kinase2 （JAK2） and signal transducer and activator of transcription3 （STAT3, Ser727）. After blockage of P2Y1 receptor and deprivation of oxygen-glucose-serum, AG490 （inhibitor of JAK2） reduced phosphorylation of STAT3 （Ser727） as well as expression of GFAP; LY294002, an inhibitor of phosphatidylinositol 3-kinase （PI3-K）, decreased phosphorylation of Akt and CREB; the inhibitor of mitogen-activated protein kinase kinase 1/2 （MEK 1/2） U0126, an important molecule of Ras/extracellular signal- regulated kinase （ERK） signaling pathway, decreased the phosphorylation of JAK2, STAT3 （Ser727）, Akt and CREB. Conclusion These results suggest that P2Y1 receptor plays a role in the production of GFAP and GDNF in astrocytes under transient ischemic condition and the related signaling pathways may be JAK2/STAT3 and PI3-K/Akt/CREB, respectively, and that crosstalk probably exists between them.

Morphological and serum hyaluronic acid, laminin and type Ⅳ collagen changes in dimethylnitrosamine-induced hepatic fibrosis of rats

AIM： To study the morphological and serum hyaluronic acid （HA）, laminin （LN）, and type IV collagen changes in hepatic fibrosis of rats induced by dimethylnitrosamine （DMN）.METHODS： The rat model of liver fibrosis was induced by DMN. Serum HA, type IV collagen, and LN were measured by ELISA. The liver/weight index and morphological changes were examined under electron microscope on d 7, 14, 21, and 28 by immunohistochemical alpha smooth muscle actin α-SMA staining as well as Sirius-red and HE staining.RESULTS： The levels of serum HA, type IV collagen and LN significantly increased from d 7 to d 28 （P = 0.043）. The liver/weight index increased on d 7 and decreased on d 28. In the model group, the rat liver stained with lie and Sirius-red showed evident hemorrhage and necrosis in the central vein of hepatic 10 Iobules on d 7. Thin fibrotic septa were formed joining central areas of the liver on d 14. The number of α-SMA positive cells was markedly increased in the model group. Transitional hepatic stellate cells were observed under electron microscope. All rats in the model group showed micronodular fibrosis in the hepatic parenchyma and a network of α-SMA positive cells. Typical myofibroblasts were embedded in the core of a fibrous septum. Compared to the control group, the area-density percentage of collagen fibrosis and pathologic grading were significantly different in the model group （P〈0.05） on different d （7, 14, and 28）. The area-density percentage of collagen fibrosis in hepatic tissue had a positive correlation with the levels of serum HA, LN, and type IV collagen.CONCLUSION： The morphological and serum HA, type IV collagen, and LN are changed in DMN-induced liver fibrosis in rats.

Preparation of High Molecular Weight Products by Crosslinking Protein Isolated from the Enzymatic Processing of Chromium-Containing Collagenous Waste:I.Extraction of Gelatin

Disposal of chromium-containing collagenous waste,generated during the processing of leather,is a problem that is being addressed not only in the United States,but also world-wide.Alternative disposal methods are being sought because of environmental concerns and rising landfill costs.We have developed a process in which this waste can be treated with a variety of enzymes to extract gelatin and a hydrolysate.These recovered protein fractions,practically devoid of chromium,could be used in a wide range of products,including adhesives,cosmetics,films,encapsulating agents,animal feed and fertilizer.A chromium product is also isolated that can be chemically treated and recycled back into the tanning process.Finally,we have shown,by using a computer-assisted process simulation and cost estimation,that a profit could be realized by the tanneries,not only by reducing the need to landfill but also from the return from the sale of the protein products.

复合涂膜保鲜剂对番荔枝模拟贮运期间品质的影响

研究大黄与五倍子复合涂膜保鲜剂涂膜对番荔枝模拟贮运期间贮藏品质的影响,明确该保鲜剂的保鲜效果。将保鲜剂涂膜的番荔枝作为处理组、未涂膜的果实作为对照(CK),分别置于加冰的泡沫箱中贮藏20 h模拟当地贮运技术,之后开箱放置于常温下贮藏,考察复合涂膜保鲜剂对番荔枝感官品质及其生理生化的影响。结果表明,与CK组比较,经涂膜处理后番荔枝果实的裂果、烂果、霉果和失重情况明显改善,褐变指数和乙烯释放量显著降低;有效延缓了果实软化,延迟了呼吸高峰第1次出现的时间,抑制呼吸高峰的第2次出现,可显著降低淀粉酶活性、减缓淀粉转化为可溶性固形物的速度。该保鲜剂可有效延缓番荔枝模拟贮运期间果实的衰老,起到较为理想的保鲜效果。

Idiopathic fistula-in-ano

Fistula-in-ano is the most common form of perineal sepsis.Typically,a fistula includes an internal opening,a track,and an external opening.The external opening might acutely appear following infection and/or an abscess,or more insiduously in a chronic manner.Management includes control of infection,assessment of the fistulous track in relation to the anal sphincter muscle,and finally,definitive treatment of the fistula.Fistulotomy was the most commonly used mode of management,but concerns about post-fistulotomy incontinence prompted the use of sphincter preserving techniques such as advancement flaps,fibrin glue,collagen fistula plug,ligation of the intersphincteric fistula track,and stem cells.Many descriptive and comparative studies have evaluated these different techniques with variable outcomes.The lack of consistent results,level I evidence,or long-term follow-up,as well as the heterogeneity of fistula pathology has prevented a definitive treatment algorithm.This article will review the most commonly available modalities and techniques for managing idiopathic fistula-in-ano.

Adult islets cultured in collagen gel transdifferentiate into duct-like cells

AIM: To establish a model of islet-ductal cell transdifferen-tiation to identify the transdifferentiated cells. METHODS: Collagen was extracted from rat tail at first. Purified rat islets were divided into three groups, embedded in collagen gel and incubated respectively in DMEM/F12 alone (control group), DMEM/F12 plus epidermal growth factor (EGF), DMEM/F12 plus EGF and cholera toxin (CT). Transdifferentiation was proved by microscopy, RT-PCR, immunohistochemistry and RIA. RESULTS: Islets embedded in collagen gel plus EGF and CT were cystically transformed and could express new gene cytokeratin 19 while still maintaining the expression of insulin and Pdx-1 genes. Immunohistochemistry demonstrated that the protein of cytokeratin 19 was only expressed in the third group. The insulin content secreted by islets in the third group decreased significantly during the transdiffe-rentiation. CONCLUSION: CT is a crucial factor for the islet-ductal cell transdifferentiation.

Evaluation of diffusion in gel entrapment cell culture within hollow fibers

AIM: To investigate diffusion in mammalian cell culture by gel entrapment within hollow fibers. METHODS: Freshly isolated rat hepatocytes or human oral epidermoid carcinoma (KB) cells were entrapped in type I collagen solutions and statically cultured inside microporous and ultrafiltration hollow fibers. During the culture time collagen gel contraction, cell viability and specific function were assessed. Effective diffusion coefficients of glucose in cell-matrix gels were determined by lag time analysis in a diffusion cell. RESULTS: Significant gel contractions occurred in the collagen gels by entrapment of either viable hepatocytes or KB cells. And the gel contraction caused a significant reduction on effective diffusion coefficient of glucose. The cell viability assay of both hepatocytes and KB cells statically cultured in hollow fibers by collagen entrapment further confirmed the existence of the inhibited mass transfer by diffusion. Urea was secreted about 50% more by hepatocytes entrapped in hollow fibers with pore size of 0.1 μm than that in hollow fibers with MWCO of 100 ku. CONCLUSION: Cell-matrix gel and membrane pore size are the two factors relevant to the limited mass transfer by diffusion in such gel entrapment of mammalian cell culture.

Collagen-based biological glue after Appleby operation for advanced gastric cancer

Pancreatic fistula is a common complication of distal pancreatectomy; although various surgical procedures have been proposed, no clear advantage is evident for a single technique. We herein report the case of a 38-year-old patient affected by an advanced gastric carcinoma infiltrating the pancreas body, with exten- sive nodal metastases involving the celiac trunk, who underwent total gastrectomy with lymphadenectomy, distal pancreatectomy and resection en bloc of the celiac trunk (Appleby operation). At the end of the demolitive phase, the pancreatic stump and the aorta at the level of the celiac ligature were covered with a layer of Tachosil, a horse collagen sponge made with human coagulation factors (fibrinogen and thrombin). Presenting this case, we wish to highlight the possible sealing effect of this product and hypothesize a role in preventing pancreatic fistula and postoperative lymphorrhagia from extensive nodal dissection.

Preparation and surface characterization of nanodisk/nanoflower-structured gallium-doped zinc oxide as a catalyst for sensor applications

Nanostructured gallium‐doped zinc oxide （GZO） thin films were fabricated on piezoelectric sub‐strates. The GZO thin films with nanodisk/nanoflower morphologies were prepared by a simple spin‐coating process followed by one‐step hydrothermal treatment. Addition of polymer during hydrothermal treatment resulted in nanodisk and nanoflower morphologies. The morphology, microstructure and chemical composition of thin films prepared under different conditions were examined by field‐emission scanning electron microscopy （FE‐SEM）, X‐ray diffraction （XRD） and Raman spectroscopy. The XRD and FE‐SEM investigations confirmed that the GZO nanodisks, na‐norods and nanoflowers formed on the AlN/Si substrates were all wurtzite phase. Green fluorescent protein （GFP） was immobilized on the as‐synthesized GZO nanostructured materials by a dipping process. Atomic force microscopy （AFM） and fluorescence spectroscopy measurements were con‐ducted to confirm the surface binding nature of GFP on the GZO nanostructures to determine their suitability for use in sensor applications and bioimaging techniques. Trace‐level addition of GFP to the GZO nanostructures resulted in a fluorescence response, revealing good activity for ultraviolet light sensor applications.

Effects of transport on aerosols over the eastern slope of the Tibetan Plateau:synergistic contribution of Southeast Asia and the Sichuan Basin

The aerosol optical properties and chemical components of PM2.1(particulate matter with a diameter of 2.1μm or less)were investigated at Mount Gongga on the eastern slope of the Tibetan Plateau from April 2012 to December 2014.The annual mean aerosol optical depth(AOD)was 0.35±0.23,and the?ngstr?m exponent was 1.0±0.38.The AOD exhibited higher values in summer and winter,but lower values in spring and autumn.Dividing the observational periods into dry and wet seasons,the authors found that the concentrations of K^+,elemental carbon,secondary inorganic aerosols,and primary and secondary organic carbon in the dry(wet)season were 0.29(0.21),0.88(0.60),7.4(4.5),7.5(5.1),and 3.9(12)μg m?3,respectively.Combined with trajectory analysis,the authors found that higher concentrations of K^+,elemental carbon,and primary organic carbon indicated the effects of biomass burning from Southeast Asia during the dry season.However,the oxidation of volatile organic compounds was the main source of aerosols during the wet season,which originated from the Sichuan Basin.

Selective catalytic reduction of NO with NH_3 over sol-gel-derived CuO-CeO_2-MnO_x/γ-Al_2O_3 catalysts

Granular CuO-CeO2-MnOx/γ-Al2O3 catalysts were synthesized by the sol-gel method. The performance of the CuO-CeO2-MnOx/γ-Al2O3 catalysts for the selective catalytic reduction (SCR) was studied in a fixed bed system. Preliminary tests were carried out to analyze the behavior of NH3 and NO over catalyst in the presence of oxygen. The optimum temperature range for SCR over the CuO-CeO2-MnOx/γ-Al2O3 catalysts is 300-400 ℃ . The catalysts maintain nearly 100% NO conversion at 350 ℃. The NH3 oxidation experiments show that both NO and N2O are produced gradually with the increase of temperature. The catalysts in this experiment have a stronger oxidation property on NH3, which improves the denitrification activity at low temperature. The over-oxidation of NH3 at high temperature is the main cause leading to a decrease in the NO conversion. The NH3 and NO desorption experiments show that NH3 and NO can be adsorbed on CuO-CeO2-MnOx/γ-Al2O3 granular catalysts. The transient response of NH3 and NO indicates that the SCR reaction proceeds in accordance with the Eley-Rideal mechanism. The adsorbed NO has little influence on the denitrification activity in SCR process.

A novel fabrication of meso-porous silica film by sol-gol of TEOS

A homogeneous crack-free nano- or meso-porous silica films on silicon was fabricated by colloidal silica sol derived by hydrolyzing tetraethyl orthosilicate (TEOS) catalyzing with (C4H9)4N+OH- in water medium. The solution with ratio of H2O/TEOS15, R4N+ and glycerol as templates, combining with the hydrolyzed intermediate, controlled the silica aggregating; the templated silica film with heterostructure was developed into homogeneous nano-porous then meso-porous silica films after being annealed from 750 C to 850 C; the formation mechanism of the porous silica films was discussed; morphologies of the silica films were characterized. The refractive indexes of the porous silica films were 1.2561.458, the thermal conductivity < 0.7 W/m/K. The fabricating procedure and the sequence had not been reported before.

MOUSE ANTIBODY RESPONSE FOLLOWING REPETITIVE INJECTIONS OF GAMMA－IRRADIATED HUMAN PLACENTA COLLAGEN

Injectable bovine collagen has been used clinically for years. But both the necessity of repeated injections to maintain corrections and the question of adverse allergic reactions developing from the use of a xenogenic collagen have been an area of serious concern. To overoome these adverse effects, we have developed injectable collagen preparations from human placenta. Gamma irradiation was used for sterilization and crosslinkins of the collagen.We observed the mouse immune respose to gamma-irradiated human placenta soluble and insoluble collagen following multiple injections. After six injections of these materials, no total IgG level increase was found, nor was antibody specifically directed against human collagen found.Mouse antibody levels were also observed following Zyderm II and Zyplast repetitive injections and following repetitive implantations of coated vicryl and chromic gut. No humoral immune response was found in this heterologous type system.

A COMPARATIVE STUDY OF GUT SUTURE, HUMAN AMNION COLLAGEN, BOVINE SKIN COLLAGEN AND VICRYL SUTURE IMPLANTS IN RATS

This study compares the persistence and histological characteristics of gut suture with those of human amnion collagen, bovine collagen, and Vicryl suture implants in rats. Gut suture and human amnion collagen more resembled living tissue than did bovine collagen and were characterized by their cel1ularity and the presence of numerous capillaries. The Vicryl suture implants were quickly absorbed. Picrosirius polarization revealed the synthesis of host collagen by rat fibroblasts which immigrated into the gut suture and human amnion collagen implants. The authors suggest the potential of gut suture as a soft tissue substitute to improve linear skin contour deficits.

Application of collagen-chitosan/fibrin glue asymmetric scaffolds in skin tissue engineering

To create a scaffold that is suitable for the construction of tissue-engineered skin, a novel asymmetric porous scaffold with different pore sizes on either side was prepared by combining a collagen-chitosan porous membrane with fibrin glue. Tissue-engineered skin was fabricated using this asymmetric scaffold, fibroblasts, and a human keratinocyte line (HaCaT). Epidermal cells could be seen growing easily and achieved confluence on the fibrin glue on the upper surface of the scaffold. Scanning electron microscopy showed typical shuttle-like fibroblasts adhering to the wall of the scaffold and fluorescence microscopy showed them growing in the dermal layer of the scaffold. The constructed composite skin substitute had a histological structure similar to that of normal skin tissue after three weeks of culture. The results of our study suggest that the asymmetric scaffold is a promising biologically functional material for skin tissue engineering, with prospects for clinical applications.

Effects of Electroacupuncture on Serum Indexes of Rats with Hepatic Fibrosis

Objective： To observe the effects of electroacupuncture on the histopathological changes and serum indexes of rats＇ liver, and to investigate the mechanism of electroacupuncture in treating hepatic fibrosis of rats. Methods： The rat model of hepatic fibrosis was induced with carbon tetrachloride. Then, the rats were divided into electroacupuncture group, medicine group, and model group. The collagen of liver, and serum hyaluronic acid （HA）, laminin （LN）, procollagen Ⅲ （PⅢNP）, and collagen Ⅳ （C-Ⅳ） were detected with morphologic methods and radioimmunoassay. Results： Compared with normal rats, the collagen was hyperplasia in the liver tissue, and the contents of the serum HA, LN, and PⅢ NP were higher in the model group. The collagen area of liver tissue, and the contents of the serum HA, and LN were lower in rats treated with electroacupuncture than model rats. The contents of serum of PⅢ NP, and C-Ⅳ changed little. Conclusion： Electroacupuncture had some effects of prevention and treatment, and the mechanism may relate to the effects of electroacupuncture in protecting liver cells, inhibiting synthesis of extracellular matrix, and promoting the breakup of collagen.