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Sample records for basement membrane collagen

  1. Immunochemical and autoantigenic properties of the globular domain of basement membrane collagen (type IV).

    Science.gov (United States)

    von der Mark, H; Oberbäumer, I; Timpl, R; Kemler, R; Wick, G

    1985-02-01

    Polyclonal rabbit antibodies raised against the globular domain NC1 of collagen IV from human placenta and a mouse tumor react with conformational antigenic determinants present on the NC1 hexamers and also with the three major subunits obtained after dissociation. The antibodies recognized unique structures within basement membranes and showed a broad tissue reactivity but only limited species cross-reactivity. Using these antibodies, it was possible to detect small amounts of collagen IV antigens from cell cultures and in serum. Monoclonal rat antibodies against mouse NC1 revealed a similar reaction potential. Autoantibodies could be produced in mice against mouse NC1 which react with kidney and lung basement membranes in a pathological manner, mimicking Goodpasture syndrome.

  2. Collagen IV and basement membrane at the evolutionary dawn of metazoan tissues.

    Science.gov (United States)

    Fidler, Aaron L; Darris, Carl E; Chetyrkin, Sergei V; Pedchenko, Vadim K; Boudko, Sergei P; Brown, Kyle L; Gray Jerome, W; Hudson, Julie K; Rokas, Antonis; Hudson, Billy G

    2017-04-18

    The role of the cellular microenvironment in enabling metazoan tissue genesis remains obscure. Ctenophora has recently emerged as one of the earliest-branching extant animal phyla, providing a unique opportunity to explore the evolutionary role of the cellular microenvironment in tissue genesis. Here, we characterized the extracellular matrix (ECM), with a focus on collagen IV and its variant, spongin short-chain collagens, of non-bilaterian animal phyla. We identified basement membrane (BM) and collagen IV in Ctenophora, and show that the structural and genomic features of collagen IV are homologous to those of non-bilaterian animal phyla and Bilateria. Yet, ctenophore features are more diverse and distinct, expressing up to twenty genes compared to six in vertebrates. Moreover, collagen IV is absent in unicellular sister-groups. Collectively, we conclude that collagen IV and its variant, spongin, are primordial components of the extracellular microenvironment, and as a component of BM, collagen IV enabled the assembly of a fundamental architectural unit for multicellular tissue genesis.

  3. Assessment of proteolytic degradation of the basement membrane: a fragment of type IV collagen as a biochemical marker for liver fibrosis

    DEFF Research Database (Denmark)

    Veidal, Sanne S.; Karsdal, Morten A.; Nawrocki, Arkadiusz

    2011-01-01

    Collagen deposition and an altered matrix metalloproteinase (MMP) expression profile are hallmarks of fibrosis. Type IV collagen is the most abundant structural basement membrane component of tissue, which increases 14-fold during fibrogenesis in the liver. Proteolytic degradation of collagens...

  4. Role of 17 beta-estradiol on type IV collagen fibers volumetric density in the basement membrane of bladder wall.

    Science.gov (United States)

    de Fraga, Rogerio; Dambros, Miriam; Miyaoka, Ricardo; Riccetto, Cássio Luís Zanettini; Palma, Paulo César Rodrigues

    2007-10-01

    The authors quantified the type IV collagen fibers volumetric density in the basement membrane of bladder wall of ovariectomized rats with and without estradiol replacement. This study was conducted on 40 Wistar rats (3 months old) randomly divided in 4 groups: group 1, remained intact (control); group 2, submitted to bilateral oophorectomy and daily replacement 4 weeks later of 17 beta-estradiol for 12 weeks; group 3, sham operated and daily replacement 4 weeks later of sesame oil for 12 weeks; and group 4, submitted to bilateral oophorectomy and killed after 12 weeks. It was used in immunohistochemistry evaluation using type IV collagen polyclonal antibody to stain the fibers on paraffin rat bladder sections. The M-42 stereological grid system was used to analyze the fibers. Ovariectomy had an increase effect on the volumetric density of the type IV collagen fibers in the basement membrane of rat bladder wall. Estradiol replacement in castrated animals demonstrated a significative difference in the stereological parameters when compared to the castrated group without hormonal replacement. Surgical castration performed on rats induced an increasing volumetric density of type IV collagen fibers in the basement membrane of rats bladder wall and the estradiol treatment had a significant effect in keeping a low volumetric density of type IV collagen fibers in the basement membrane of rats bladder wall.

  5. Collagen metabolism and basement membrane formation in cultures of mouse mammary epithelial cells: Induction of assembly on fibrillar type I collagen substrata

    International Nuclear Information System (INIS)

    David, G.; van der Schueren, B.; van den Berghe, H.; Nusgens, B.; Van Cauwenberge, D.; Lapiere, C.

    1987-01-01

    Collagen metabolism was compared in cultures of mouse mammary epithelial cells maintained on plastic or fibrillar type I collagen gel substrata. The accumulation of dialysable and non-dialysable [ 3 H]hydroxyproline and the identification of the collagens produced suggest no difference between substrata in the allover rates of collagen synthesis and degradation. The proportion of the [ 3 H]collagen which accumulates in the monolayers of cultures on collagen, however, markedly exceeds that of cultures on plastic. Cultures on collagen deposit a sheet-like layer of extracellular matrix materials on the surface of the collagen fibers. Transformed cells on collagen produce and accumulate more [ 3 H]collage, yet are less effective in basement membrane formation than normal cells, indicting that the accumulation of collagen alone and the effect of interstitial collagen thereupon do not suffice. Thus, exogenous fibrillar collagen appears to enhance, but is not sufficient for proper assembly of collagenous basement membrane components near the basal epithelial cell surface

  6. Deletion of the basement membrane heparan sulfate proteoglycan type XVIII collagen causes hypertriglyceridemia in mice and humans.

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    Joseph R Bishop

    2010-11-01

    Full Text Available Lipoprotein lipase (Lpl acts on triglyceride-rich lipoproteins in the peripheral circulation, liberating free fatty acids for energy metabolism or storage. This essential enzyme is synthesized in parenchymal cells of adipose tissue, heart, and skeletal muscle and migrates to the luminal side of the vascular endothelium where it acts upon circulating lipoproteins. Prior studies suggested that Lpl is immobilized by way of heparan sulfate proteoglycans on the endothelium, but genetically altering endothelial cell heparan sulfate had no effect on Lpl localization or lipolysis. The objective of this study was to determine if extracellular matrix proteoglycans affect Lpl distribution and triglyceride metabolism.We examined mutant mice defective in collagen XVIII (Col18, a heparan sulfate proteoglycan present in vascular basement membranes. Loss of Col18 reduces plasma levels of Lpl enzyme and activity, which results in mild fasting hypertriglyceridemia and diet-induced hyperchylomicronemia. Humans with Knobloch Syndrome caused by a null mutation in the vascular form of Col18 also present lower than normal plasma Lpl mass and activity and exhibit fasting hypertriglyceridemia.This is the first report demonstrating that Lpl presentation on the lumenal side of the endothelium depends on a basement membrane proteoglycan and demonstrates a previously unrecognized phenotype in patients lacking Col18.

  7. Fibrosis is not just fibrosis - basement membrane modelling and collagen metabolism differs between hepatitis B- and C-induced injury

    DEFF Research Database (Denmark)

    Nielsen, M J; Karsdal, M A; Kazankov, K

    2016-01-01

    and fibrosis only in CHC. Basement membrane collagen fragments P4NP7S and C4M were significantly higher in matched activity and fibrosis cohorts within CHB vs CHC. CONCLUSION: The main parameters to determine extracellular matrix biomarker levels are inflammation, fibrosis, and type of viral insult. Compared...... fragments in plasma from 197 chronic hepatitis B (CHB) patients and 403 chronic hepatitis C (CHC) patients matched for inflammation grade and fibrosis stage. Markers of matrix metalloprotease degraded type I, III, IV and VI collagen (C1M, C3M, C4M, C6M) and type III and IV collagen formation (Pro-C3, P4NP7S......). RESULTS: P4NP7S, C3M, C4M and C6M were significantly elevated in CHB compared to CHC. In contrast, Pro-C3 was significantly elevated in CHC compared to CHB. Pro-C3, C3M and C4M were increased in parallel with inflammation and fibrosis in both cohorts. C6M and P4NP7S were associated with inflammation...

  8. An in vitro model of the glomerular capillary wall using electrospun collagen nanofibres in a bioartificial composite basement membrane.

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    Sadie C Slater

    Full Text Available The filtering unit of the kidney, the glomerulus, contains capillaries whose walls function as a biological sieve, the glomerular filtration barrier. This comprises layers of two specialised cells, glomerular endothelial cells (GEnC and podocytes, separated by a basement membrane. Glomerular filtration barrier function, and dysfunction in disease, remains incompletely understood, partly due to difficulties in studying the relevant cell types in vitro. We have addressed this by generation of unique conditionally immortalised human GEnC and podocytes. However, because the glomerular filtration barrier functions as a whole, it is necessary to develop three dimensional co-culture models to maximise the benefit of the availability of these cells. Here we have developed the first two tri-layer models of the glomerular capillary wall. The first is based on tissue culture inserts and provides evidence of cell-cell interaction via soluble mediators. In the second model the synthetic support of the tissue culture insert is replaced with a novel composite bioartificial membrane. This consists of a nanofibre membrane containing collagen I, electrospun directly onto a micro-photoelectroformed fine nickel supporting mesh. GEnC and podocytes grew in monolayers on either side of the insert support or the novel membrane to form a tri-layer model recapitulating the human glomerular capillary in vitro. These models will advance the study of both the physiology of normal glomerular filtration and of its disruption in glomerular disease.

  9. Immunohistochemical distribution of laminin-332 and collagen type IV in the basement membrane of normal horses and horses with induced laminitis.

    Science.gov (United States)

    Visser, M B; Pollitt, C C

    2011-07-01

    The basement membrane (BM) is a thin layer of extracellular matrix that regulates cell functions as well as providing support to tissues of the body. Primary components of the BM of epithelial tissues are laminin-332 (Ln-332) and collagen type IV. Equine laminitis is a disease characterized by destruction and dislocation of the hoof lamellar BM. Immunohistochemistry was used to characterize the distribution of Ln-332 and collagen type IV in the organs of normal horses and these proteins were found to be widespread. Analysis of a panel of tissue samples from horses with experimentally-induced laminitis revealed that Ln-332 and collagen type IV degradation occurs in the skin and stomach in addition to the hoof lamellae. These findings suggest that BM degradation is common to many epithelial tissues during equine laminitis and suggests a role for systemic trigger factors in this disease. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

  10. Basement membrane proteoglycans are of epithelial origin in rodent skin

    DEFF Research Database (Denmark)

    Yamane, Y; Yaoita, H; Couchman, J R

    1996-01-01

    proteoglycan and rat and mouse perlecan. While the isolated rat epidermis was shown to completely lack rat basement membrane chondroitin sulfate proteoglycan and rat basement membrane heparan sulfate proteoglycans, including perlecan, immunofluorescence staining of tissue sections from the grafted sites......-epidermal junction and hair follicle epithelium are of epidermal (epithelial) origin in vivo. Stratified rat keratinocytes cultured on a collagen matrix at the air-liquid interface showed the synthesis of perlecan, laminin 1, and type IV collagen in basement membranes, but not clearly detectable basement membrane...

  11. Reticular Basement Membrane Vessels Are Increased in COPD Bronchial Mucosa by Both Factor VIII and Collagen IV Immunostaining and Are Hyperpermeable

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    Amir Soltani

    2012-01-01

    Full Text Available Background and Objective. Using Collagen IV staining, we have previously reported that the reticular basement membrane (Rbm is hypervascular and the lamina propria (LP is hypovascular in COPD airways. This study compared Collagen IV staining with vessels marked with anti-Factor VIII and examined vessel permeability in bronchial biopsies from COPD and normal subjects using albumin staining. Results. Anti-Collagen IV antibody detected more vessels in the Rbm (P=0.002 and larger vessels in both Rbm (P<0.001 and LP (P=0.003 compared to Factor VIII. COPD airways had more vessels (with greater permeability in the Rbm (P=0.01 and fewer vessels (with normal permeability in the LP compared to controls with both Collagen IV and Factor VIII antibodies (P=0.04 and P=0.01. Conclusion. Rbm vessels were increased in number and were hyperpermeable in COPD airways. Anti-Collagen IV and anti-Factor VIII antibodies did not uniformly detect the same vessel populations; the first is likely to reflect larger and older vessels with the latter reflecting smaller, younger vessels.

  12. Basement membrane proteoglycans are of epithelial origin in rodent skin

    DEFF Research Database (Denmark)

    Yamane, Y; Yaoita, H; Couchman, J R

    1996-01-01

    . For in vivo experiments, pieces of newborn rat epidermis obtained by dispase treatment were grafted onto athymic nude mice. Three and six weeks after grafting, immunofluorescence analysis of the grafted skin was carried out, using monoclonal antibodies specific for rat basement membrane chondroitin sulfate...... on mice demonstrated the presence of rat basement membrane chondroitin sulfate proteoglycan and rat perlecan on interfollicular and follicular basement membranes including that separating dermal papillae from adjacent hair follicle epithelium. In contrast, the basement membranes of all dermal capillaries......-epidermal junction and hair follicle epithelium are of epidermal (epithelial) origin in vivo. Stratified rat keratinocytes cultured on a collagen matrix at the air-liquid interface showed the synthesis of perlecan, laminin 1, and type IV collagen in basement membranes, but not clearly detectable basement membrane...

  13. Cell invasion through basement membrane

    OpenAIRE

    Morrissey, Meghan A; Hagedorn, Elliott J; Sherwood, David R

    2013-01-01

    Cell invasion through basement membrane is an essential part of normal development and physiology, and occurs during the pathological progression of human inflammatory diseases and cancer. F-actin-rich membrane protrusions, called invadopodia, have been hypothesized to be the “drill bits” of invasive cells, mediating invasion through the dense, highly cross-linked basement membrane matrix. Though studied in vitro for over 30 y, invadopodia function in vivo has remained elusive. We have recent...

  14. Cell invasion through basement membrane

    Science.gov (United States)

    Morrissey, Meghan A; Hagedorn, Elliott J; Sherwood, David R

    2013-01-01

    Cell invasion through basement membrane is an essential part of normal development and physiology, and occurs during the pathological progression of human inflammatory diseases and cancer. F-actin-rich membrane protrusions, called invadopodia, have been hypothesized to be the “drill bits” of invasive cells, mediating invasion through the dense, highly cross-linked basement membrane matrix. Though studied in vitro for over 30 y, invadopodia function in vivo has remained elusive. We have recently discovered that invadopodia breach basement membrane during anchor cell invasion in C. elegans, a genetically and visually tractable in vivo invasion event. Further, we found that the netrin receptor DCC localizes to the initial site of basement membrane breach and directs invasion through a single gap in the matrix. In this commentary, we examine how the dynamics and structure of AC-invadopodia compare with in vitro invadopodia and how the netrin receptor guides invasion through a single basement membrane breach. We end with a discussion of our surprising result that the anchor cell pushes the basement membrane aside, instead of completely dissolving it through proteolysis, and provide some ideas for how proteases and physical displacement may work together to ensure efficient and robust invasion. PMID:24778942

  15. The major basement membrane components localize to the chondrocyte pericellular matrix--a cartilage basement membrane equivalent?

    DEFF Research Database (Denmark)

    Kvist, Alexander J.; Nyström, Alexander; Hultenby, Kjell

    2007-01-01

    In this study, we demonstrate that articular cartilage chondrocytes are surrounded by the defining basement membrane proteins laminin, collagen type IV, nidogen and perlecan, and suggest that these form the functional equivalent of a basement membrane. We found by real-time PCR that mouse...... to the progression of degenerative joint disorders....

  16. Basement membrane proteoglycans and development

    DEFF Research Database (Denmark)

    Couchman, J R; Abrahamson, D R; McCarthy, K J

    1993-01-01

    -CSPG was only strongly expressed in the vasculature invading late comma stage glomeruli, and later in presumptive and mature Bowman's capsule. Over the first six to eight weeks, the capillary basement membranes contained BM-CSPG, but in gradually decreasing amounts until it became completely undetectable...

  17. Basement Membrane Defects in Genetic Kidney Diseases

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    Christine Chew

    2018-01-01

    Full Text Available The glomerular basement membrane (GBM is a specialized structure with a significant role in maintaining the glomerular filtration barrier. This GBM is formed from the fusion of two basement membranes during development and its function in the filtration barrier is achieved by key extracellular matrix components including type IV collagen, laminins, nidogens, and heparan sulfate proteoglycans. The characteristics of specific matrix isoforms such as laminin-521 (α5β2γ1 and the α3α4α5 chain of type IV collagen are essential for the formation of a mature GBM and the restricted tissue distribution of these isoforms makes the GBM a unique structure. Detailed investigation of the GBM has been driven by the identification of inherited abnormalities in matrix proteins and the need to understand pathogenic mechanisms causing severe glomerular disease. A well-described hereditary GBM disease is Alport syndrome, associated with a progressive glomerular disease, hearing loss, and lens defects due to mutations in the genes COL4A3, COL4A4, or COL4A5. Other proteins associated with inherited diseases of the GBM include laminin β2 in Pierson syndrome and LMX1B in nail patella syndrome. The knowledge of these genetic mutations associated with GBM defects has enhanced our understanding of cell–matrix signaling pathways affected in glomerular disease. This review will address current knowledge of GBM-associated abnormalities and related signaling pathways, as well as discussing the advances toward disease-targeted therapies for patients with glomerular disease.

  18. Glomerular basement membrane composition and the filtration barrier.

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    Miner, Jeffrey H

    2011-09-01

    The glomerular basement membrane (GBM) is an especially thick basement membrane that contributes importantly to the kidney's filtration barrier. The GBM derives from the fusion of separate podocyte and endothelial cell basement membranes during glomerulogenesis and consists primarily of laminin-521 (α5β2γ1), collagen α3α4α5(IV), nidogens-1 and -2, and agrin. Of these nine proteins, mutations in the genes encoding four of them (LAMB2, COL4A3, COL4A4, and COL4A5) cause glomerular disease in humans as well as in mice. Furthermore, mutation of a fifth (Lama5) gene in podocytes in mice causes proteinuria, nephrotic syndrome, and progression to renal failure. These results highlight the importance of the GBM for establishing and maintaining a properly functioning glomerular filtration barrier.

  19. Coarctation induces alterations in basement membranes in the cardiovascular system

    DEFF Research Database (Denmark)

    Lipke, D W; McCarthy, K J; Elton, T S

    1993-01-01

    A coarctation hypertensive rat model was used to examine the effects of elevated blood pressure on basement membrane component synthesis by cardiac myocytes and aorta using immunohistochemistry and Northern blot analysis. Carotid arterial pressure increased immediately on coarctation, and left...... with regard to protein and tissue type affected as well as intensity of the changes. However, changes in mRNA levels (but not protein deposition) for perlecan and type IV collagen were also observed in aortas from hypertensive rats compared with controls. Increases in steady-state mRNA levels for all basement...

  20. Immunohistochemical localization of basement membrane components during hair follicle morphogenesis

    DEFF Research Database (Denmark)

    Westgate, G E; Shaw, D A; Harrap, G J

    1984-01-01

    Specific antisera were used to investigate the distributions of several basement membrane zone (BMZ) components, namely, bullous pemphigoid antigen (BPA), heparan sulfate proteoglycan (HSPG), laminin, and type IV collagen, during the development of hair follicles in late embryo rats. BPA was not ......Specific antisera were used to investigate the distributions of several basement membrane zone (BMZ) components, namely, bullous pemphigoid antigen (BPA), heparan sulfate proteoglycan (HSPG), laminin, and type IV collagen, during the development of hair follicles in late embryo rats. BPA...... of the elongating follicle. HSPG was associated with the basal cell layer prior to the appearance of hair follicle primordia and became BMZ-associated before birth but after follicle buds were first observed. HSPG was also found to be associated with the basal cell surfaces in the epidermis, but not in the hair...... follicle. Laminin and type IV collagen were continually present in epidermal and follicular BMZ both before and during development of hair follicles and were later present in the dermal papilla matrix. From these observations we conclude that (1) laminin and type IV collagen are functionally important...

  1. ROCK1-directed basement membrane positioning coordinates epithelial tissue polarity.

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    Daley, William P; Gervais, Elise M; Centanni, Samuel W; Gulfo, Kathryn M; Nelson, Deirdre A; Larsen, Melinda

    2012-01-01

    The basement membrane is crucial for epithelial tissue organization and function. However, the mechanisms by which basement membrane is restricted to the basal periphery of epithelial tissues and the basement membrane-mediated signals that regulate coordinated tissue organization are not well defined. Here, we report that Rho kinase (ROCK) controls coordinated tissue organization by restricting basement membrane to the epithelial basal periphery in developing mouse submandibular salivary glands, and that ROCK inhibition results in accumulation of ectopic basement membrane throughout the epithelial compartment. ROCK-regulated restriction of PAR-1b (MARK2) localization in the outer basal epithelial cell layer is required for basement membrane positioning at the tissue periphery. PAR-1b is specifically required for basement membrane deposition, as inhibition of PAR-1b kinase activity prevents basement membrane deposition and disrupts overall tissue organization, and suppression of PAR-1b together with ROCK inhibition prevents interior accumulations of basement membrane. Conversely, ectopic overexpression of wild-type PAR-1b results in ectopic interior basement membrane deposition. Significantly, culture of salivary epithelial cells on exogenous basement membrane rescues epithelial organization in the presence of ROCK1 or PAR-1b inhibition, and this basement membrane-mediated rescue requires functional integrin β1 to maintain epithelial cell-cell adhesions. Taken together, these studies indicate that ROCK1/PAR-1b-dependent regulation of basement membrane placement is required for the coordination of tissue polarity and the elaboration of tissue structure in the developing submandibular salivary gland.

  2. Co-deposition of basement membrane components during the induction of murine splenic AA amyloid

    DEFF Research Database (Denmark)

    Lyon, A W; Narindrasorasak, S; Young, I D

    1991-01-01

    Past studies have demonstrated that during murine AA amyloid induction there is co-deposition of the AA amyloid peptide and the basement membrane form of heparan sulfate proteoglycan. The synthesis and accumulation of heparan sulfate proteoglycan does not usually occur in the absence of other...... basement membrane components, such as type IV collagen, laminin, and fibronectin. Using immunohistochemical techniques, the present experiments have demonstrated that in addition to the heparan sulfate proteoglycan, there are other basement membrane components present in splenic AA amyloid deposits...... and these are present as soon as AA amyloid deposits are detectable. The results indicate that within the time constraints imposed by the experiments, the basement membrane components, fibronectin, laminin, type IV collagen, and heparan sulfate proteoglycan are co-deposited 36 to 48 hours after the AgNO3 and amyloid...

  3. The Acinar Cage: Basement Membranes Determine Molecule Exchange and Mechanical Stability of Human Breast Cell Acini.

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    Aljona Gaiko-Shcherbak

    Full Text Available The biophysical properties of the basement membrane that surrounds human breast glands are poorly understood, but are thought to be decisive for normal organ function and malignancy. Here, we characterize the breast gland basement membrane with a focus on molecule permeation and mechanical stability, both crucial for organ function. We used well-established and nature-mimicking MCF10A acini as 3D cell model for human breast glands, with ether low- or highly-developed basement membrane scaffolds. Semi-quantitative dextran tracer (3 to 40 kDa experiments allowed us to investigate the basement membrane scaffold as a molecule diffusion barrier in human breast acini in vitro. We demonstrated that molecule permeation correlated positively with macromolecule size and intriguingly also with basement membrane development state, revealing a pore size of at least 9 nm. Notably, an intact collagen IV mesh proved to be essential for this permeation function. Furthermore, we performed ultra-sensitive atomic force microscopy to quantify the response of native breast acini and of decellularized basement membrane shells against mechanical indentation. We found a clear correlation between increasing acinar force resistance and basement membrane formation stage. Most important native acini with highly-developed basement membranes as well as cell-free basement membrane shells could both withstand physiologically relevant loads (≤ 20 nN without loss of structural integrity. In contrast, low-developed basement membranes were significantly softer and more fragile. In conclusion, our study emphasizes the key role of the basement membrane as conductor of acinar molecule influx and mechanical stability of human breast glands, which are fundamental for normal organ function.

  4. Collective cell behavior on basement membranes floating in space

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    Ellison, Sarah; Bhattacharjee, Tapomoy; Morley, Cameron; Sawyer, W.; Angelini, Thomas

    The basement membrane is an essential part of the polarity of endothelial and epithelial tissues. In tissue culture and organ-on-chip devices, monolayer polarity can be established by coating flat surfaces with extracellular matrix proteins and tuning the trans-substrate permeability. In epithelial 3D culture, spheroids spontaneously establish inside-out polarity, morphing into hollow shell-like structures called acini, generating their own basement membrane on the inner radius of the shell. However, 3D culture approaches generally lack the high degree of control provided by the 2D culture plate or organ-on-chip devices, making it difficult to create more faithful in vitro tissue models with complex surface curvature and morphology. Here we present a method for 3D printing complex basement membranes covered in cells. We 3D print collagen-I and Matrigel into a 3D growth medium made from jammed microgels. This soft, yielding material allows extracellular matrix to be formed as complex surfaces and shapes, floating in space. We then distribute MCF10A epithelial cells across the polymerized surface. We envision employing this strategy to study 3D collective cell behavior in numerous model tissue layers, beyond this simple epithelial model.

  5. Rat hair follicle dermal papillae have an extracellular matrix containing basement membrane components

    DEFF Research Database (Denmark)

    Couchman, J R

    1986-01-01

    Dermal papillae are small mesenchymally derived zones at the bases of hair follicles which have an important role in hair morphogenesis in the embryo and control of the hair growth cycle in postnatal mammals. The cells of the papilla are enmeshed in a dense extracellular matrix which undergoes...... extensive changes in concert with the hair cycle. Here it is shown that this matrix in anagen pelage follicles of postnatal rats contains an abundance of basement membrane components rather than dermal components such as interstitial collagens. In particular, type IV collagen, laminin, and basement membrane...

  6. Basement membrane abnormalities in human eyes with diabetic retinopathy

    DEFF Research Database (Denmark)

    Ljubimov, A V; Burgeson, R E; Butkowski, R J

    1996-01-01

    Vascular and parenchymal basement membranes (BMs) are thickened in diabetes, but alterations in individual BM components in diabetic eyes, especially in diabetic retinopathy (DR), are obscure. To identify abnormalities in the distribution of specific constituents, we analyzed cryostat sections...... of human eyes obtained at autopsy (seven normal, five diabetic without DR, and 13 diabetic with DR) by immunofluorescence with antibodies to 30 BM and extracellular matrix components. In non-DR eyes, no qualitative changes of ocular BM components were seen. In some DR corneas, epithelial BM was stained...... discontinuously for laminin-1, entactin/nidogen, and alpha3-alpha4 Type IV collagen, in contrast to non-DR corneas. Major BM alterations were found in DR retinas compared to normals and non-DR diabetics. The inner limiting membrane (retinal BM) of DR eyes had accumulations of fibronectin (including cellular...

  7. Basement membrane abnormalities in human eyes with diabetic retinopathy

    DEFF Research Database (Denmark)

    Ljubimov, A V; Burgeson, R E; Butkowski, R J

    1996-01-01

    discontinuously for laminin-1, entactin/nidogen, and alpha3-alpha4 Type IV collagen, in contrast to non-DR corneas. Major BM alterations were found in DR retinas compared to normals and non-DR diabetics. The inner limiting membrane (retinal BM) of DR eyes had accumulations of fibronectin (including cellular......Vascular and parenchymal basement membranes (BMs) are thickened in diabetes, but alterations in individual BM components in diabetic eyes, especially in diabetic retinopathy (DR), are obscure. To identify abnormalities in the distribution of specific constituents, we analyzed cryostat sections...... of human eyes obtained at autopsy (seven normal, five diabetic without DR, and 13 diabetic with DR) by immunofluorescence with antibodies to 30 BM and extracellular matrix components. In non-DR eyes, no qualitative changes of ocular BM components were seen. In some DR corneas, epithelial BM was stained...

  8. Accelerating repaired basement membrane after bevacizumab treatment on alkali-burned mouse cornea

    Science.gov (United States)

    Lee, Koon-Ja; Lee, Ji-Young; Lee, Sung Ho; Choi, Tae Hoon

    2013-01-01

    To understand the corneal regeneration induced by bevacizumab, we investigated the structure changes of stroma and basement membrane regeneration. A Stick soaked in 0.5 N NaOH onto the mouse cornea and 2.5 mg/ml of bevacizumab was delivered into an alkali-burned cornea (2 μl) by subconjunctival injections at 1 hour and 4 days after injury. At 7 days after injury, basement membrane regeneration was observed by transmission electron microscope. Uneven and thin epithelial basement membrane, light density of hemidesmosomes, and edematous collagen fibril bundles are shown in the alkali-burned cornea. Injured epithelial basement membrane and hemidesmosomes and edematous collagen fibril bundles resulting from alkali-burned mouse cornea was repaired by bevacizumab treatment. This study demonstrates that bevacizumab can play an important role in wound healing in the cornea by accelerating the reestablishment of basement membrane integrity that leads to barriers for scar formation. [BMB Reports 2013; 46(4): 195-200] PMID:23615260

  9. Glomerular basement membrane lipidosis in Alagille syndrome.

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    Davis, Jessica; Griffiths, Ryan; Larkin, Kay; Rozansky, David; Troxell, Megan

    2010-06-01

    Alagille syndrome is characterized by a paucity of interlobular bile ducts with chronic cholestasis, cardiac, skeletal, and eye abnormalities and is associated predominantly with JAG1 mutations. Various renal abnormalities have been sporadically described. The classic renal histopathology described in Alagille syndrome is mesangiolipidosis, with lipid deposits predominately confined to the mesangium and minimal deposition within the glomerular basement membrane (GBM). We report a 5-year-old girl with Alagille syndrome who presented with persistent subnephrotic proteinuria and renal tubular acidosis. A renal biopsy showed GBM irregularities (mimicking membranous glomerulonephritis), mesangial sclerosis, and focal segmental glomerulosclerosis (FSGS) on light microscopy. Electron microscopy revealed few lipid inclusions within the mesangium but extensive inclusions along the GBM. These findings are mostly consistent with those reported previously in Alagille syndrome. However, the histologic distribution of lipid vacuoles is seemingly reversed in this patient and is uniquely accompanied by FSGS, emphasizing the spectrum of renal histopathology seen in Alagille syndrome. The proteinuria observed in this patient is likely attributed to significant GBM lipid deposition, which over time may contribute to the development of FSGS.

  10. The basement membrane and tumor progression in the uterine cervix.

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    Nair, S A; Nair, M B; Jayaprakash, P G; Rajalekshmy, T N; Nair, M K; Pillai, M R

    1997-06-01

    Immunocytochemical localization of the basement membrane (BM) proteins laminin, type-IV collagen and fibronectin were analyzed in normal cervical epithelium, low grade squamous intraepithelial lesions (SILs), high grade SILs and invasive squamous cell carcinoma (SCC) of the uterine cervix. A regular, thick and continuous BM was present in normal cervical epithelium and low grade SIL. Interruptions and discontinuity of the BM were more evident in high grade SILs. There was a good correlation between increasing severity of the lesion and increasing number of breaks. In SCC, the distribution of laminin, collagen IV and fibronectin was related to the degree of cellular differentiation, with decreased immunoreactivity being evident in moderately and poorly differentiated tumors. As the invasive potential of the tumor increased, the fragmentation and loss of BM was more evident. Fibronectin showed only moderate to mild immunoreactivity in normal cervical epithelium and low grade SILs. However, the intensity of expression increased in high grade SILs especially in the peritumoral stroma. It may therefore be concluded from these results that snythesis and reabsorption of BM proteins may be related to shifts in cellular metabolism during tumorigenesis.

  11. Accelerating repaired basement membrane after bevacizumab treatment on alkali-burned mouse cornea

    Directory of Open Access Journals (Sweden)

    Koon-Ja Lee

    2013-04-01

    Full Text Available To understand the corneal regeneration induced by bevacizumab,we investigated the structure changes of stroma andbasement membrane regeneration. A Stick soaked in 0.5 NNaOH onto the mouse cornea and 2.5 mg/ml of bevacizumabwas delivered into an alkali-burned cornea (2 μl by subconjunctivalinjections at 1 hour and 4 days after injury. At 7 daysafter injury, basement membrane regeneration was observedby transmission electron microscope. Uneven and thin epithelialbasement membrane, light density of hemidesmosomes,and edematous collagen fibril bundles are shown in thealkali-burned cornea. Injured epithelial basement membraneand hemidesmosomes and edematous collagen fibril bundlesresulting from alkali-burned mouse cornea was repaired bybevacizumab treatment. This study demonstrates that bevacizumabcan play an important role in wound healing in thecornea by accelerating the reestablishment of basementmembrane integrity that leads to barriers for scar formation.[BMB Reports 2013; 46(4: 195-200

  12. Basement membrane chondroitin sulfate proteoglycans: localization in adult rat tissues

    DEFF Research Database (Denmark)

    McCarthy, K J; Couchman, J R

    1990-01-01

    Heparan sulfate proteoglycans have been described as the major proteoglycan component of basement membranes. However, previous investigators have also provided evidence for the presence of chondroitin sulfate glycosaminoglycan in these structures. Recently we described the production and characte...

  13. Involvement of MIF in basement membrane damage in chronically UVB-exposed skin in mice.

    Directory of Open Access Journals (Sweden)

    Yoko Yoshihisa

    Full Text Available Solar ultraviolet (UV B radiation is known to induce matrix metalloproteinases (MMPs that degrade collagen in the basement membrane. Macrophage migration inhibitory factor (MIF is a pluripotent cytokine that plays an essential role in the pathophysiology of skin inflammation induced by UV irradiation. This study examined the effects of MIF on basement membrane damage following chronic UVB irradiation in mice. The back skin of MIF transgenic (Tg and wild-type (WT mice was exposed to UVB three times a week for 10 weeks. There was a decrease in intact protein levels of type IV collagen and increased basement membrane damage in the exposed skin of the MIF Tg mice compared to that observed in the WT mice. Moreover, the skin of the MIF Tg mice exhibited higher MIF, MMP-2 and MMP-9 expression and protein levels than those observed in the WT mice. We also found that chronic UVB exposure in MIF Tg mice resulted in higher levels of neutrophil infiltration in the dermis compared with that observed in the WT mice. In vitro experiments revealed that MIF induced increases in the MMPs expression, including that of MMP-9 in keratinocytes and MMP-2 in fibroblasts. Cultured neutrophils also secreted MMP-9 stimulated by MIF. Therefore, MIF-mediated basement membrane damage occurs primarily through MMPs activation and neutrophil influx in murine skin following chronic UVB irradiation.

  14. Alterations of epithelial adhesion molecules and basement membrane components in lattice corneal dystrophy (LCD).

    Science.gov (United States)

    Resch, Miklós D; Schlötzer-Schrehardt, Ursula; Hofmann-Rummelt, Carmen; Kruse, Friedrich E; Seitz, Berthold

    2009-08-01

    The aim of the study was to investigate the histopathological and ultrastructural correlate of delayed epithelial healing in eyes with lattice corneal dystrophy (LCD). Corneal buttons from 4 patients with LCD (two with subepithelial, two with stromal amyloid deposits) and 2 control corneas were examined. Cell-matrix adhesion molecules and basement membrane components of the corneal epithelium were analyzed by immunohistochemistry and hemidesmosomes between epithelium and stroma were quantified by transmission electron microscopy (TEM). By TEM well-developed hemidesmosomes anchored the basal epithelial cells to the underlying basement membrane in all normal and LCD corneas. Hemidesmosome density was not significantly different in subepithelial (224.7 +/- 34.1/100 microm) and stromal (234.3 +/- 36.3/100 microm) LCD compared to controls (241.3 +/- 26.8/100 microm). The basement membrane was interrupted in subepithelial, but continuous in stromal LCD. Integrin alpha6 and beta4 staining formed a continuous line along the basal surface of the corneal epithelium in control corneas, whereas it appeared discontinuous and patchy both in subepithelial and stromal forms of LCD. Staining for alphaV integrin showed irregular staining patterns, i.e. enhanced labelling intensity in subepithelial and interrupted pattern in stromal LCD, respectively. Integrins alpha3, beta1, beta2, and beta5, dystroglycan, and plectin were not markedly different in dystrophic corneas. Type VII collagen showed a discontinuous staining in subepithelial forms of LCD. In stromal forms of LCD, type VII collagen staining occurred in additional patches underneath the epithelial basement membrane zone. Type XVII collagen staining was reduced in subepithelial LCD. Laminin-1, laminin-5 and laminin gamma2 showed variable irregular staining patterns in dystrophic corneas with focal interruptions, focal thickenings, and reduplications of basement membrane. Some irregularities in corneas with subepithelial

  15. Distribution of individual components of basement membrane in human colon polyps and adenocarcinomas as revealed by monoclonal antibodies

    DEFF Research Database (Denmark)

    Ljubimov, A V; Bartek, J; Couchman, J R

    1992-01-01

    -membrane components (laminin, entactin/nidogen, collagen type IV and large heparan sulfate proteoglycan), as well as to keratin 8. In all adenocarcinomas, including mucinous, basement membranes were altered more at the invasive front than in the parenchyma. The degree of this alteration was inversely correlated......-membrane components and to a specific keratin may constitute an adequate immunohistochemical test for the presence of invasion, and may be useful in the histologic analysis of polyps, especially in dubious cases....

  16. Mouse endometrial stromal cells produce basement-membrane components

    DEFF Research Database (Denmark)

    Wewer, U M; Damjanov, A; Weiss, J

    1986-01-01

    . Mouse decidual cells isolated from 6- to 7-day pregnant uteri explanted in vitro continue to synthesize basement-membrane-like extracellular matrix. Using immunohistochemistry and metabolic labeling followed by immunoprecipitation, SDS-PAGE, and fluorography, it was shown that the decidual cells...... to undergo pseudodecidualization. We thus showed that stromal cells from pregnant and nonpregnant mouse uteri synthesize significant amounts of basement-membrane components in vitro, and hence could serve as a good model for the study of normal basement-membrane components.......During mouse pregnancy, uterine stromal cells transform into morphologically distinct decidual cells under the influence of the implanting embryo and a proper hormonal environment. Mechanical stimulation of hormonally primed uterine stromal cells leads to the same morphologic alterations...

  17. Ultrastructural localization of the core protein of a basement membrane-specific chondroitin sulfate proteoglycan in adult rat skin

    DEFF Research Database (Denmark)

    McCarthy, K J; Horiguchi, Y; Couchman, J R

    1990-01-01

    Basement membranes are complex extracellular matrices present at epithelial/mesenchymal interfaces of tissues. The dermal-epidermal junction has been shown to contain numerous components, some of the most well known being laminin, types IV and VII collagens, heparan sulfate proteoglycan, fibronec...

  18. Direct Observation of Early-Stage High-Dose Radiotherapy-Induced Vascular Injury via Basement Membrane-Targeting Nanoparticles.

    Science.gov (United States)

    Au, Kin Man; Hyder, Sayed Nabeel; Wagner, Kyle; Shi, Caihong; Kim, Young Seok; Caster, Joseph M; Tian, Xi; Min, Yuanzeng; Wang, Andrew Z

    2015-12-22

    Collagen IV-targeting peptide-conjugated basement membrane-targeting nanoparticles are successfully engineered to identify early-stage blood vessel injury induced by high-dose radiotherapy. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Quantitative Proteome Analysis Reveals Increased Content of Basement Membrane Proteins in Arteries from Patients with Type 2 Diabetes and Lower Levels among Metformin Users

    DEFF Research Database (Denmark)

    Rørdam Preil, Simone; Kristensen, Lars P; Beck, Hans C

    2015-01-01

    analysis was done by iTRAQ-labelling and LC-MS/MS analysis on individual arterial samples. The amounts of the basement membrane (BM) components, alpha-1- and alpha-2- type IV collagen, gamma-1- and beta-2-laminin were significantly increased in patients with diabetes. Moreover, the expressions of basement...... of collagen-stainable material in tunica intima and media among patients with diabetes. CONCLUSIONS: -The distinct accumulation of arterial basement membrane proteins in type 2 diabetes discloses a similarity between the diabetic macro- and micro-angiopathy and suggests a molecular explanation behind...

  20. Mouse endometrial stromal cells produce basement-membrane components

    DEFF Research Database (Denmark)

    Wewer, U M; Damjanov, A; Weiss, J

    1986-01-01

    . Mouse decidual cells isolated from 6- to 7-day pregnant uteri explanted in vitro continue to synthesize basement-membrane-like extracellular matrix. Using immunohistochemistry and metabolic labeling followed by immunoprecipitation, SDS-PAGE, and fluorography, it was shown that the decidual cells...

  1. Coarctation induces alterations in basement membranes in the cardiovascular system

    DEFF Research Database (Denmark)

    Lipke, D W; McCarthy, K J; Elton, T S

    1993-01-01

    A coarctation hypertensive rat model was used to examine the effects of elevated blood pressure on basement membrane component synthesis by cardiac myocytes and aorta using immunohistochemistry and Northern blot analysis. Carotid arterial pressure increased immediately on coarctation, and left ve...

  2. Nephritogenic antigen determinants in epidermal and renal basement membranes of kindreds with Alport-type familial nephritis.

    Science.gov (United States)

    Kashtan, C; Fish, A J; Kleppel, M; Yoshioka, K; Michael, A F

    1986-10-01

    We probed epidermal basement membranes (EBM) of acid-urea denatured skin from members of kindreds with Alport-type familial nephritis (FN) for the presence of antigens reactive with Goodpasture sera (GPS) and serum (FNS) from an Alport patient who developed anti-glomerular basement membrane (GBM) nephritis in a renal allograft. By immunoblotting, GPS reacted primarily with the 28,000 molecular weight (mol wt) monomer but also the 24,000 mol wt and 26,000 mol wt monomers of the noncollagenous globular domain (NC1) of type IV collagen from normal human GBM, while FNS identified only the 26,000-mol wt monomer. FNS reacted with EBM of 12 controls and nine unaffected male kindred members but not EBM of eight affected males. Five affected females exhibited interrupted reactivity of FNS with EBM. GPS showed variable reactivity with EBM and was not discriminating with respect to Alport-type FN. FNS did not stain renal basement members of five affected males. However, the EBM, tubular basement membrane, and Bowman's capsules of affected males contained antigens reactive with GPS. These immunochemical studies suggest that the FNS antigen is distinct from Goodpasture antigen(s). The expression of FNS antigen located on the NC1 domain of type IV collagen is altered in basement membranes of patients with Alport-type FN, and the distribution of this antigenic anomaly within kindreds suggests X-linked dominant transmission of a defective gene.

  3. Basement membrane proteoglycans in glomerular morphogenesis: chondroitin sulfate proteoglycan is temporally and spatially restricted during development

    DEFF Research Database (Denmark)

    McCarthy, K J; Bynum, K; St John, P L

    1993-01-01

    basement membrane (GBM) but present in other basement membranes of the nephron, including collecting ducts, tubules, Bowman's capsule, and the glomerular mesangium. In light of this unique pattern of distribution and of the complex histoarchitectural reorganization occurring during nephrogenesis...

  4. Organogenesis of the kidney glomerulus: focus on the glomerular basement membrane.

    Science.gov (United States)

    Miner, Jeffrey H

    2011-01-01

    The glomerular basement membrane (GBM) is a crucial component of the kidney's filtration barrier that separates the vasculature from the urinary space. During glomerulogenesis, the GBM is formed from fusion of two distinct basement membranes, one synthesized by the glomerular epithelial cell (podocyte) and the other by the glomerular endothelial cell. The main components of the GBM are laminin-521 (α5β2γ1), collagen α3α4α5(IV), nidogen and the heparan sulfate proteoglycan, agrin. By studying mice lacking specific GBM components, we have shown that during glomerulogenesis, laminin is the only one that is required for GBM integrity and in turn, the GBM is required for completion of glomerulogenesis and glomerular vascularization. In addition, our results from laminin β2-null mice suggest that laminin-521, and thus the GBM, contribute to the establishment and maintenance of the glomerular filtration barrier to plasma albumin. In contrast, mutations that affect GBM collagen IV or agrin do not impair glomerular development or cause immediate leakage of plasma proteins. However, collagen IV mutation, which causes Alport syndrome and ESRD in humans, leads to gradual damage to the GBM that eventually leads to albuminuria and renal failure. These results highlight the importance of the GBM for establishing and maintaining a perfectly functioning, highly selective glomerular filter.

  5. Immunological characterization of a basement membrane-specific chondroitin sulfate proteoglycan

    DEFF Research Database (Denmark)

    McCarthy, K J; Accavitti, M A; Couchman, J R

    1989-01-01

    Reichert's membrane, an extraembryonic membrane present in developing rodents, has been proposed as an in vivo model for the study of basement membranes. We have used this membrane as a source for isolation of basement membrane proteoglycans. Reichert's membranes were extracted in a guanidine/3-[...

  6. Association of Randall's Plaques with Collagen Fibers and Membrane Vesicles

    Science.gov (United States)

    Khan, Saeed R.; Rodriguez, Douglas E.; Gower, Laurie B.; Monga, Manoj

    2013-01-01

    Background Idiopathic calcium oxalate (CaOx) kidney stones develop by deposition of CaOx crystals on Randall's plaques (RP). Mechanisms involved in RP formation are still unclear. Objective It is our hypotheses that RP formation is similar to vascular calcification involving components of extracellular matrix including membrane bound vesicles (MV) and collagen fibers. In order to verify our hypothesis we critically examined renal papillary tissue from stone patients. Methods 4 mm cold-cup biopies of renal papillae were performed on fifteen idiopathic stone patients undergoing PCNL. Tissue was immediately fixed and processed for analyses by various light and electron microscopic techniques. Results and Limitations Spherulitic CaP crystals, the hallmark of RP's, were seen in all samples examined. They were seen in interstitium as well as laminated basement membrane of tubular epithelia. Large crystalline deposits comprised of dark elongated strands mixed with spherulites. Strands showed banded patterns similar to collagen. Crystal deposits were surrounded by collagen fibers and membrane bound vesicles. Energy dispersive x-ray microanalyses (EDX) and electron diffraction identified the crystals as hydroxyapatite. The number of kidneys examined is small and urinary data was not available for all the patients. Conclusions Results presented here show that crystals in the Randall's plaques are associated with both the collagen as well as MV. Collagen fibers appeared calcified and vesicles contained crystals. We conclude that crystal deposition in renal papillae may have started with membrane vesicle induced nucleation and grew by addition of crystals on the periphery within a collagen framework. PMID:22266007

  7. The timeline of lamellar basement membrane changes during equine laminitis development.

    Science.gov (United States)

    Visser, M B; Pollitt, C C

    2011-07-01

    The timing of lamellar basement membrane (BM) changes occurring during laminitis development is incompletely understood. To determine the temporal progression of lamellar BM changes and whether laminin-332 (Ln-332) γ2 cleavage products are generated during laminitis development. Eight clinically normal Standardbred horses were allocated into treatment (n = 5) or sham (n = 3) groups. The treatment group received, via nasogastric intubation, an oligofructose (OF) bolus (10 g/kg bwt) while the sham group was given water. Laminitis induction proceeded for 48 h followed by euthanasia. Lamellar biopsies were obtained prior to dosing and at intervals during the treatment period for analysis (at 12, 18, 24, 30 and 36 h and at 48 h following euthanasia). Changes in lamellar collagen type IV and Ln-332 were first observed at 12 h post dosing. A unique pattern of reactivity for the Ln-332 γ2 antibody D4B5 occurred, in which reactivity was observed only in lamellar tissue affected by laminitis. No bioactive Ln-332 γ2 proteolytic fragments were detected in lamellar samples. Basement membrane changes occurred early during the laminitis process. Direct Ln-332 γ2 cleavage to release biologically active products did not appear to occur. Thus loss of stability or protein interaction of the BM is probably responsible for the γ2 specific reactivity observed. Basement membrane changes may a first step in lamellar failure occurring prior to detection with conventional methods. Thus, more sensitive detection methods of BM changes are required to study laminitis development. © 2011 EVJ Ltd.

  8. Effects of radiation on the permeability of human basement membranes

    Science.gov (United States)

    Fan, B.-T.; Achour, S.; Simmonet, F.; Guerin, D.

    1999-02-01

    The influence of radiation on the permeability properties of human basement membrane was investigated by measuring the diffusion rate of several organic compounds (glycine, proline, glucose, urea and insulin) through human anterior lens capsules. The basement membranes borne an γ-irradiation treatment change significantly their permeability vis-a-vis studied organic substances. This modification in physico-chemical properties is probably due to the radiation, which alters or degrades the complex structure (or architecture) of basement membranes. Moreover the change in permeability is dependent upon the diffusing compounds. An increase in diffusion has been observed for glucose, glycine and urea. However for insulin and proline, a decrease in diffusion rate was observed. L'influence de radiation sur la perméabilité de la membrane basale a été étudiée par la mesure de la vitesse de diffusion de plusieurs composés organiques d'intérêt biologique (glycine, proline, glucose, urée et insuline) à travers la lame basale antérieure du cristallin de l'oil humain. Les membranes basales qui sont traitées avec l'irradiation γ changent significativement leur perméabilité vis-à-vis des substances organiques. Ce changement de propriétés physico-chimiques est probablement dû à l'altération ou la dégradation de la structure (ou de l'architecture) de la membrane basale entraînée par l'irradiation. De plus, la modification de la perméabilité de la membrane basale est dépendante des composés diffusants. Une augmentation de la vitesse de diffusion a été observée pour le glucose, le glycine et l'urée. Par contre, dans les cas de l'insuline et de la proline, on a observé une diminution de la vitesse de diffusion.

  9. Ultrastructure of Reichert's membrane, a multilayered basement membrane in the parietal wall of the rat yolk sac.

    Science.gov (United States)

    Inoué, S; Leblond, C P; Laurie, G W

    1983-11-01

    The ultrastructure of Reichert's membrane, a thick basement membrane in the parietal wall of the yolk sac, has been examined in 13-14-d pregnant rats. This membrane is composed of more or less distinct parallel layers, each one of which resembles a common basement membrane. After routine fixation in glutaraldehyde followed by osmium tetroxide, the layers appear to be mainly composed of 3-8-nm thick cords arranged in a three-dimensional network. Loosely scattered among the cords are unbranched, straight tubular structures with a diameter of 7-10 nm, which mainly run parallel to the surface and to one another; they are referred to as basotubules. Permanganate fixation emphasizes the presence of a thick feltwork of irregular material around basotubules. Finally, minute dot-like structures measuring 3.5 nm and referred to as double pegs are present within the meshes of the cord network. Reichert's membranes have been treated for 2-48 h at 25 degrees C with plasmin, a proteolytic enzyme known to rapidly digest laminin and fibronectin. After a 2-h treatment, most of the substance of the cords is digested away leaving a three-dimensional network of 1.5-2.0-nm thick filaments. The interpretation is that the cords are formed of a plasmin-resistant core filament and a plasmin-extractable sheath. When plasmin treatment is prolonged for 15 h or longer, the filaments are dissociated and disappear, while basotubules are maintained. Plasmin digestion also reveals that basotubules are composed of two parts: a ribbon-like helical wrapping and tubule proper. Further changes in the tubule under plasmin influence are interpreted as a dissociation into pentagonal units suggestive of the presence of the amyloid P component. After 48 h of plasmin treatment, basotubules are further disaggregated and dispersed, leaving only linearly arranged double pegs. Reichert's membranes with or without a 2-hr plasmin treatment have been immunostained by exposure to antibodies against either laminin or

  10. [Relationship between the changes in ischemia/reperfusion cerebro-microvessel basement membrane injury and gelatinase system in senile rat].

    Science.gov (United States)

    Li, Jian-sheng; Liu, Ke; Liu, Jing-xia; Wang, Ming-hang; Zhao, Yue-wu; Liu, Zheng-guo

    2008-11-01

    To study the relationship of cerebro-microvessel basement membrane injury and gelatinase system after cerebral ischemia/reperfusion (I/R) in aged rats. Cerebral I/R injury model was reproduced by intraluminal silk ligature thrombosis of the middle cerebral artery occlusion (MCAO). Rats were divided randomly into sham control and I/R groups in young rats [ischemia 3 hours (I 3 h) and reperfusion 6 hours (I/R 6 h), 12 hours (I/R 12 h), 24 hours (I/R 24 h), 3 days (I/R 3 d), 6 days (I/R 6 d)], and sham control group and I/R group in aged rats (I 3 h and I/R 6 h, I/R 12 h, I/R 24 h , I/R 3 d, I/R 6 d). The change in cerebro-cortex microvessel basement membrane structure, basement membrane type IV collagen (Col IV) and laminin (LN) contents, matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) expression in every group were determined with immunohistochemical method and zymogram analysis. With the increase in age, Col IV and LN contents of the microvessel basement membrane were increased, and MMP-2 and MMP-9 expressions were stronger. With prolongation of I/R, the degradation of microvessel basement membrane components (Col IV and LN) was positively correlated with the duration of cerebral I/R. MMP-2 expression was increased gradually, and MMP-9 and TIMP-1 expression increased at the beginning and decreased subsequently. Col IV(I 3 h, I/R 6 h , I/R 12 h), LN (I 3 h, I/R 6-24 h), MMP-2 (I 3 h, I/R 6 h-6 d) and MMP-9 (I 3 h, I/R 6-24 h) expression level in aged rats with I/R injury were higher, and TIMP-1 (I/R 24 h) expression was lower than those in young rats (Pcerebro-microvessel basement membrane in rats is related with MMPs and TIMP. Cerebro-microvessel basement membrane injury is more serious in aged rats than that of young rats. Changes in cerebro-microvessel basement membrane injury in aged rats is related with gelatinase system change.

  11. Morphological diagnosis of Alport syndrome and thin basement membrane nephropathy by low vacuum scanning electron microscopy.

    Science.gov (United States)

    Okada, Shinichi; Inaga, Sumire; Kitamoto, Koichi; Kawaba, Yasuo; Nakane, Hironobu; Naguro, Tomonori; Kaidoh, Toshiyuki; Kanzaki, Susumu

    2014-01-01

    Alport syndrome (AS) and thin basement membrane nephropathy (TBMN) are genetic disorders caused by mutations of the type IV collagen genes COL4A3, COL4A4, and/or COL4A5. We here aimed to investigate the three-dimensional ultrastructure of the glomerular basement membrane (GBM) in order to introduce a novel method of diagnosing AS and TBMN. The subjects were 4 patients with AS and 6 patients with TBMN. Conventional renal biopsy paraffin sections from AS and TBMN patients were stained with periodic acid methenamine silver (PAM) and observed directly under low vacuum scanning electron microscopy (LVSEM). The PAM-positive GBMs were clearly visible under LVSEM through the overlying cellular components. The GBMs showed characteristic coarse meshwork appearances in AS, and thin and sheet-like appearances in TBMN. At the cut side view of the capillary wall, the GBMs in AS appeared as fibrous inclusions between a podocyte and an endothelial cell, while the GBMs in TBMN showed thin linear appearances. These different findings of GBMs between AS and TBMN were easily observed under LVSEM. Thus, we conclude that three-dimensional morphological evaluation by LVSEM using conventional renal biopsy paraffin sections will likely be useful for the diagnosis of AS and TBMN, including for retrospective investigations.

  12. Immunohistochemical expression of basement membrane proteins of verrucous carcinoma of the oral mucosa.

    Science.gov (United States)

    Arduino, Paolo G; Carrozzo, Marco; Pagano, Marco; Broccoletti, Roberto; Scully, Crispian; Gandolfo, Sergio

    2010-06-01

    Squamous cell carcinoma (SCC) of the oral cavity is an extremely invasive tumour of stratified squamous epithelium that spreads throughout degradation of the basement membrane (BM) and extra-cellular matrix. Oral verrucous carcinoma (VC) is a rare low-grade variant of oral SCC that penetrates into the subepithelial connective tissue. It also has a different clinical behaviour from classical oral SCC. We investigated the immunohistochemical expression of laminin, laminin-5, collagen IV and fibronectin in VC, severe epithelial dysplasia (SED) and SCC in order to analyse if the pattern of these molecules expression contributes to the differences in the biological behaviour of these diseases. The staining pattern of laminin was less intensive in SCC compared with SED and VC, and collagen IV expression was increased in VC compared with SED. Discontinuities of laminin, collagen IV and fibronectin were more evident in SED than in VC. This study indicates that VC has a biological behaviour different from SED or SCC, observable by immunohistochemistry in the BM zone.

  13. Investigation of basement membrane proteins in a case of granular cell ameloblastoma

    Science.gov (United States)

    Lapthanasupkul, Puangwan; Poomsawat, Sopee; Chindasombatjaroen, Jira

    2012-01-01

    Granular cell ameloblastoma is a rare, benign neoplasm of the odontogenic epithelium. A case of massive granular cell ameloblastoma in a 44-year-old Thai female is reported. Histopathological features displayed a follicular type of ameloblastoma with an accumulation of granular cells residing within the tumor follicles. After treatment by partial mandibulectomy, the patient showed a good prognosis without recurrence in a 2-year follow-up. To characterize the granular cells in ameloblastoma, we examined the expression of basement membrane (BM) proteins, including collagen type IV, laminins 1 and 5 and fibronectin using immunohistochemistry. Except for the granular cells, the tumor cells demonstrated a similar expression of BM proteins compared to follicular and plexiform ameloblastomas in our previous study, whereas the granular cells showed strong positivity to laminins 1 and 5 and fibronectin. The increased fibronectin expression in granular cells suggests a possibility of age-related transformation of granular cells in ameloblastoma. PMID:22361945

  14. MT1-MMP-mediated basement membrane remodeling modulates renal development

    Energy Technology Data Exchange (ETDEWEB)

    Riggins, Karen S.; Mernaugh, Glenda [Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Su, Yan; Quaranta, Vito [Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Koshikawa, Naohiko; Seiki, Motoharu [Division of Cancer Cell Research, Institute of Medical Science, The University of Tokyo, Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Pozzi, Ambra [Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Department of Research Medicine, Veterans Affairs Hospital, Nashville, TN 37232 (United States); Zent, Roy, E-mail: roy.zent@vanderbilt.edu [Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Department of Research Medicine, Veterans Affairs Hospital, Nashville, TN 37232 (United States)

    2010-10-15

    Extracellular matrix (ECM) remodeling regulates multiple cellular functions required for normal development and tissue repair. Matrix metalloproteinases (MMPs) are key mediators of this process and membrane targeted MMPs (MT-MMPs) in particular have been shown to be important in normal development of specific organs. In this study we investigated the role of MT1-MMP in kidney development. We demonstrate that loss of MT1-MMP leads to a renal phenotype characterized by a moderate decrease in ureteric bud branching morphogenesis and a severe proliferation defect. The kidneys of MT1-MMP-null mice have increased deposition of collagen IV, laminins, perlecan, and nidogen and the phenotype is independent of the MT-1MMP target, MMP-2. Utilizing in vitro systems we demonstrated that MTI-MMP proteolytic activity is required for renal tubule cells to proliferate in three dimensional matrices and to migrate on collagen IV and laminins. Together these data suggest an important role for MT1-MMP in kidney development, which is mediated by its ability to regulate cell proliferation and migration by proteolytically cleaving kidney basement membrane components.

  15. MT1-MMP-mediated basement membrane remodeling modulates renal development

    International Nuclear Information System (INIS)

    Riggins, Karen S.; Mernaugh, Glenda; Su, Yan; Quaranta, Vito; Koshikawa, Naohiko; Seiki, Motoharu; Pozzi, Ambra; Zent, Roy

    2010-01-01

    Extracellular matrix (ECM) remodeling regulates multiple cellular functions required for normal development and tissue repair. Matrix metalloproteinases (MMPs) are key mediators of this process and membrane targeted MMPs (MT-MMPs) in particular have been shown to be important in normal development of specific organs. In this study we investigated the role of MT1-MMP in kidney development. We demonstrate that loss of MT1-MMP leads to a renal phenotype characterized by a moderate decrease in ureteric bud branching morphogenesis and a severe proliferation defect. The kidneys of MT1-MMP-null mice have increased deposition of collagen IV, laminins, perlecan, and nidogen and the phenotype is independent of the MT-1MMP target, MMP-2. Utilizing in vitro systems we demonstrated that MTI-MMP proteolytic activity is required for renal tubule cells to proliferate in three dimensional matrices and to migrate on collagen IV and laminins. Together these data suggest an important role for MT1-MMP in kidney development, which is mediated by its ability to regulate cell proliferation and migration by proteolytically cleaving kidney basement membrane components.

  16. Quantitative image analysis of laminin immunoreactivity in skin basement membrane irradiated with 1 GeV/nucleon iron particles.

    Science.gov (United States)

    Costes, S; Streuli, C H; Barcellos-Hoff, M H

    2000-10-01

    We previously reported that laminin immunoreactivity in mouse mammary epithelium is altered shortly after whole-body irradiation with 0.8 Gy from 600 MeV/nucleon iron ions but is unaffected after exposure to sparsely ionizing radiation. This observation led us to propose that the effect could be due to protein damage from the high ionization density of the ion tracks. If so, we predicted that it would be evident soon after radiation exposure in basement membranes of other tissues and would depend on ion fluence. To test this hypothesis, we used immunofluorescence, confocal laser scanning microscopy, and image segmentation techniques to quantify changes in the basement membrane of mouse skin epidermis. At 1 h after exposure to 1 GeV/nucleon iron ions with doses from 0.03 to 1.6 Gy, neither the visual appearance nor the mean pixel intensity of laminin in the basement membrane of mouse dorsal skin epidermis was altered compared to sham-irradiated tissue. This result does not support the hypothesis that particle traversal directly affects laminin protein integrity. However, the mean pixel intensity of laminin immunoreactivity was significantly decreased in epidermal basement membrane at 48 and 96 h after exposure to 0.8 Gy 1 GeV/nucleon iron ions. We confirmed this effect with two additional antibodies raised against affinity-purified laminin 1 and the E3 fragment of the long-arm of laminin 1. In contrast, collagen type IV, another component of the basement membrane, was unaffected. Our studies demonstrate quantitatively that densely ionizing radiation elicits changes in skin microenvironments distinct from those induced by sparsely ionizing radiation. Such effects may might contribute to the carcinogenic potential of densely ionizing radiation by altering cellular signaling cascades mediated by cell-extracellular matrix interactions.

  17. Expression and deposition of basement membrane proteins by brain capillary endothelial cells in a primary murine model of the blood-brain barrier

    DEFF Research Database (Denmark)

    Thomsen, Maj Schneider; Birkelund, Svend; Larsen, Annette Burkhart

    2016-01-01

    of the present study was to create four different in vitro constructs of the murine BBB to characterise if the expression and secretion of basement membrane proteins by the murine brain capillary endothelial cells (mBCECs) was affected by co-culturing with pericytes, mixed glial cells, or both. Primary m...... membrane, and astrocyte endfeet. To study the interaction of the different cells of the BBB, construction of in vitro BBB models is valuable. However, the modulation and contribution of the cells of the BBB to the synthesis of basement membrane proteins in vitro is not fully elaborated. Thus, the aim......, and immunofluorescent labelling were used. The mBCECs were found to express major basement membrane proteins in vitro and increased expression of laminin α5 and collagen IV α1 was correlated to the addition of BBB inducing factors (hydrocortisone, Ro20-1724, pCPT-cAMP). Co-culturing of the mBCECs with pericytes, mixed...

  18. Supportive properties of basement membrane layer of human amniotic membrane enable development of tissue engineering applications.

    Science.gov (United States)

    Iranpour, Sonia; Mahdavi-Shahri, Nasser; Miri, Raheleh; Hasanzadeh, Halimeh; Bidkhori, Hamid Reza; Naderi-Meshkin, Hojjat; Zahabi, Ehsan; Matin, Maryam M

    2018-01-08

    Human amniotic membrane (HAM) has been widely used as a natural scaffold in tissue engineering due to many of its unique biological properties such as providing growth factors, cytokines and tissue inhibitors of metalloproteinases. This study aimed at finding the most suitable and supportive layer of HAM as a delivery system for autologous or allogeneic cell transplantation. Three different layers of HAM were examined including basement membrane, epithelial and stromal layers. In order to prepare the basement membrane, de-epithelialization was performed using 0.5 M NaOH and its efficiency was investigated by histological stainings, DNA quantification, biomechanical testing and electron microscopy. Adipose-derived stromal cells (ASCs) and a human immortalized keratinocyte cell line (HaCaT) were seeded on the three different layers of HAM and cultured for 3 weeks. The potential of the three different layers of HAM to support the attachment and viability of cells were then monitored by histology, electron microscopy and (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Moreover, mechanical strengths of the basement membrane were assessed before and after cell culture. The results indicated that the integrity of extra cellular matrix (ECM) components was preserved after de-epithelialization and resulted in producing an intact basement amniotic membrane (BAM). Moreover, all three layers of HAM could support the attachment and proliferation of cells with no visible cytotoxic effects. However, the growth and viability of both cell types on the BAM were significantly higher than the other two layers. We conclude that growth stimulating effectors of BAM and its increased mechanical strength after culturing of ASCs, besides lack of immunogenicity make it an ideal model for delivering allogeneic cells and tissue engineering applications.

  19. Retinoid inhibition of in vitro invasion of human amnion basement membrane by human tumor cells

    International Nuclear Information System (INIS)

    Fazely, F.

    1988-01-01

    The effects measured were the inhibition of tumor cell migration through the basement membrane (BM) and tumor cell degradative enzyme activity on 3 H-proline labeled collagenous and non collagenous components of the BM. The human lung carcinoma A549 or the human Ewing's sarcoma TC-106 cell lines treated with retinoids for two days were incubated on the BM in the absence of retinoids. A dose-dependent inhibition of cell invasion was produced by retinoids. Among the retinoids tested the most powerful was retinol acetate which inhibited invasion by 50% of A549 cells at a concentration of 0.09 μg/ml, and TC-106 cells at 0.08 μg/ml. Retinol acetate inhibited A549 and TC-106 cell growth by approximately 50% at levels almost 100-fold higher than those needed for antiinvasive activity. Retinol acetate was about 20 times more potent than retinoic acid and 30 times more than retinol palmitate. Furthermore, A549 cells treated with retinol acetate, under conditions whereby an anti-invasive state was induced,showed an increase in the number of cellular retinoic acid binding proteins (CRABP), a decrease in the activity of type IV collagenase and ectosialyltransferase, and no change in the activity of transglutaminase

  20. Chitosan facilitates structure formation of the salivary gland by regulating the basement membrane components.

    Science.gov (United States)

    Yang, Tsung-Lin; Hsiao, Ya-Chuan

    2015-10-01

    Tissue structure is important for inherent physiological function and should be recapitulated during tissue engineering for regenerative purposes. The salivary gland is a branched organ that is responsible for saliva secretion and regulation. The salivary glands develop from epithelial-mesenchymal interactions, and depend on the support of the basement membrane (BM). Chitosan-based biomaterials have been demonstrated to be competent in facilitating the formation of salivary gland tissue structure. However, the underlying mechanisms have remained elusive. In the developing submandibular gland (SMG), the chitosan effect was found to diminish when collagen and laminin were removed from cultured SMG explants. Chitosan increased the expression of BM components including collagen, laminin, and heparan sulfate proteoglycan, and also facilitated BM components and the corresponding receptors to be expressed in tissue-specific patterns beneficial for SMG branching. The chitosan effect decreased when either laminin components or receptors were inhibited, as well when the downstream signaling was blocked. Our results revealed that chitosan promotes salivary glands branching through the BM. By regulating BM components and receptors, chitosan efficiently stimulated downstream signaling to facilitate salivary gland branching. The present study revealed the underlying mechanism of the chitosan effect in engineering SMG structure formation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Anti-glomerular basement membrane disease superimposed on membranous nephropathy: a case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Nivera Noel

    2010-08-01

    Full Text Available Abstract Introduction Anti-glomerular basement membrane disease is a rare autoimmune disorder characterized by pulmonary hemorrhage, crescentic glomerulonephritis and the presence of circulating anti-glomerular basement membrane antibodies. The simultaneous occurrence of both anti-glomerular basement membrane disease and membranous nephropathy is rare. Case presentation A 59-year-old Hispanic man presented with acute onset of nausea and vomiting and was found to have renal insufficiency. Work-up included a kidney biopsy, which revealed anti-glomerular basement membrane disease with underlying membranous nephropathy. He was treated with emergent hemodialysis, intravenous corticosteroids, plasmapheresis, and cyclophosphamide without improvement in his renal function. Conclusion Simultaneous anti-glomerular basement membrane disease and membranous nephropathy is very rare. There have been 16 previous case reports in the English language literature that have been associated with a high mortality and morbidity, and a very high rate of renal failure resulting in hemodialysis. Co-existence of membranous nephropathy and anti-glomerular basement membrane disease may be immune-mediated, although the exact mechanism is not clear.

  2. Peroxynitrous acid induces structural and functional modifications to basement membranes and its key component, laminin

    DEFF Research Database (Denmark)

    Degendorfer, Georg; Chuang, Christine Y.; Hammer, Astrid

    2015-01-01

    Basement membranes (BM) are specialized extracellular matrices underlying endothelial cells in the artery wall. Laminin, the most abundant BM glycoprotein, is a structural and biologically active component. Peroxynitrous acid (ONOOH), a potent oxidizing and nitrating agent, is formed in vivo...

  3. Expression of basement membrane components through morphological changes in the hair growth cycle

    DEFF Research Database (Denmark)

    Couchman, J R; Gibson, W T

    1985-01-01

    The amount and distribution of fibronectin associated with hair follicles was found to vary during the hair growth cycle in the rat. Immunocytochemical staining of follicles in mid-late anagen (the growth stage) revealed the presence of fibronectin in the dermal papilla matrix, in the basement...... membrane separating this from the epithelial cells of the hair bulb, and in the basement membrane and connective tissue sheath which underly the cells of the outer root sheath. Early in catagen, the transitional stage, staining of the dermal papilla matrix disappeared. Fibronectin persisted in the basement...

  4. A Novel Function for the nm23-Hl Gene: Overexpression in Human Breast Carcinoma Cells Leads to the Formation of Basement Membrane and Growth Arrest

    Energy Technology Data Exchange (ETDEWEB)

    Howlett, Anthony R; Petersen, Ole W; Steeg, Patricia S; Bissell, Mina J

    1994-01-01

    We have developed a culture system using reconstituted basement membrane components in which normal human mammary epithelial cells exhibit several aspects of the development and differentiation process, including formation of acinar-like structures, production and basal deposition of basement membrane components, and production and apical secretion of sialomucins. Cell lines and cultures from human breast carcinomas failed to recapitulate this process. The data indicate the importance of cellular interactions with the basement membrane in the regulation of normal breast differentiation and, potentially, its loss in neoplasia. Our purpose was to use this assay to investigate the role of the putative metastasis suppressor gene nm23-H1 in mammary development and differentiation. The metastatic human breast carcinoma cell line MDA-MB-435, clones transfected with a control pCMVBamneo vector, and clones transfected with pCMVBamneo vector containing nm23-H1 complementary DNA (the latter of which exhibited a substantial reduction in spontaneous metastatic potential in vivo) were cultured within a reconstituted basement membrane. Clones were examined for formation of acinus-like spheres, deposition of basement membrane components, production of sialomucin, polarization, and growth arrest. In contrast to the parental cell line and control transfectants, MDA-MB-435 breast carcinoma cells overexpressing Nm23-H1 protein regained several aspects of the normal phenotype within reconstituted basement membrane. Nm23-H1 protein-positive cells formed organized acinus-like spheres, deposited the basement membrane components type IV collagen and, to some extent, laminin to the outside of the spheres, expressed sialomucin, and growth arrested. Growth arrest of Nm23-H1 protein-positive cells was preceded by and correlated with formation of a basement membrane, suggesting a causal relationship. The data indicate a previously unidentified cause-and-effect relationship between nm23-H1 gene

  5. AMACO is a component of the basement membrane-associated Fraser complex.

    Science.gov (United States)

    Richardson, Rebecca J; Gebauer, Jan M; Zhang, Jin-Li; Kobbe, Birgit; Keene, Douglas R; Karlsen, Kristina Røkenes; Richetti, Stefânia; Wohl, Alexander P; Sengle, Gerhard; Neiss, Wolfram F; Paulsson, Mats; Hammerschmidt, Matthias; Wagener, Raimund

    2014-05-01

    Fraser syndrome (FS) is a phenotypically variable, autosomal recessive disorder characterized by cryptophthalmus, cutaneous syndactyly, and other malformations resulting from mutations in FRAS1, FREM2, and GRIP1. Transient embryonic epidermal blistering causes the characteristic defects of the disorder. Fras1, Frem1, and Frem2 form the extracellular Fraser complex, which is believed to stabilize the basement membrane. However, several cases of FS could not be attributed to mutations in FRAS1, FREM2, or GRIP1, and FS displays high clinical variability, suggesting that there is an additional genetic, possibly modifying contribution to this disorder. An extracellular matrix protein containing VWA-like domains related to those in matrilins and collagens (AMACO), encoded by the VWA2 gene, has a very similar tissue distribution to the Fraser complex proteins in both mouse and zebrafish. Here, we show that AMACO deposition is lost in Fras1-deficient zebrafish and mice and that Fras1 and AMACO interact directly via their chondroitin sulfate proteoglycan (CSPG) and P2 domains. Knockdown of vwa2, which alone causes no phenotype, enhances the phenotype of hypomorphic Fras1 mutant zebrafish. Together, our data suggest that AMACO represents a member of the Fraser complex.

  6. Ultrastructure of Reichert's membrane, a multilayered basement membrane in the parietal wall of the rat yolk sac

    OpenAIRE

    1983-01-01

    The ultrastructure of Reichert's membrane, a thick basement membrane in the parietal wall of the yolk sac, has been examined in 13-14-d pregnant rats. This membrane is composed of more or less distinct parallel layers, each one of which resembles a common basement membrane. After routine fixation in glutaraldehyde followed by osmium tetroxide, the layers appear to be mainly composed of 3-8-nm thick cords arranged in a three-dimensional network. Loosely scattered among the cords are unbranched...

  7. Heparan sulfate proteoglycans made by different basement-membrane-producing tumors have immunological and structural similarities

    DEFF Research Database (Denmark)

    Wewer, U M; Albrechtsen, R; Hassell, J R

    1985-01-01

    Using immunological assays, we determined the relationship between the heparan sulfate proteoglycans produced by two different murine basement-membrane-producing tumors, i.e., the mouse Engelbreth-Holm-Swarm (EHS) tumor and the L2 rat yolk-sac tumor. Antibodies prepared against the heparan sulfate...... mainly heparan sulfate (75%) along with smaller amounts of chondroitin sulfate (19%), whereas the L2 rat yolk-sac tumor produced mainly chondroitin sulfate (76%) with smaller amounts of heparan sulfate (21%). We conclude that these two murine basement-membrane-producing tumors elaborate...

  8. Improved proliferation and differentiation capacity of human mesenchymal stromal cells cultured with basement-membrane extracellular matrix proteins.

    Science.gov (United States)

    Lindner, Ulrich; Kramer, Jan; Behrends, Jochen; Driller, Birgit; Wendler, Nils-Ole; Boehrnsen, Florian; Rohwedel, Jürgen; Schlenke, Peter

    2010-12-01

    In vitro cultured mesenchymal stromal cells (MSC) are characterized by a short proliferative lifespan, an increasing loss of proliferation capacity and progressive reduction of differentiation potential. Laminin-1, laminin-5, collagen IV and fibronectin are important constituents of the basement membrane extracellular matrix (ECM) that are involved in a variety of cellular activities, including cell attachment and motility. The in vitro proliferation capacity of MSC was significantly improved when the cells were incubated in the presence of basement membrane ECM proteins. For example, a mixture of proteins improved proliferation capacity 250-fold in comparison with standard conditions after five passages. Furthermore, in colony-forming unit-fibroblast (CFU-F) assays colony numbers and size were significantly extended. Blocking specific integrin cell-surface receptors, positive effects on the proliferation capacity of MSC were inhibited. Additionally, when MSC were co-cultivated with ECM proteins, cells maintained their multipotential differentiation capacity throughout many culture passages in comparison with cells cultivated on plastic. However, expansion of MSC on laminin-5 suppressed any subsequent chondrogenic differentiation. Our results suggest that expansion of bone marrow-derived MSC in the presence of ECM proteins is a powerful approach for generating large numbers of MSC, showing a prolonged capacity to differentiate into mesodermal cell lineages, with the exception of the lack of chondrogenesis by using laminin-5 coating.

  9. Chitosan Cross-linked Reconstituted Amniotic Collagen Membrane ...

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Chitosan Cross-linked Reconstituted Amniotic Collagen Membrane – An Excellent Cell Substratum. The KERATINOCYTE proliferation and Differentiation into multiple layers is due to the presence of type - IV collagen in the amnion. Cultured FIBROBLASTS had good ...

  10. Expression of basement membrane components through morphological changes in the hair growth cycle

    DEFF Research Database (Denmark)

    Couchman, J R; Gibson, W T

    1985-01-01

    The amount and distribution of fibronectin associated with hair follicles was found to vary during the hair growth cycle in the rat. Immunocytochemical staining of follicles in mid-late anagen (the growth stage) revealed the presence of fibronectin in the dermal papilla matrix, in the basement...... membrane separating this from the epithelial cells of the hair bulb, and in the basement membrane and connective tissue sheath which underly the cells of the outer root sheath. Early in catagen, the transitional stage, staining of the dermal papilla matrix disappeared. Fibronectin persisted in the basement...... of anagen, involving cell division and follicle elongation, was associated with a great increase in the amount of fibronectin in this zone and in and around the dermal papilla. Analysis of entry into anagen by [3H]thymidine incorporation and autoradiography revealed that growth could be detected before...

  11. Permeation of macromolecules into the renal glomerular basement membrane and capture by the tubules

    Science.gov (United States)

    Lawrence, Marlon G.; Altenburg, Michael K.; Sanford, Ryan; Willett, Julian D.; Bleasdale, Benjamin; Ballou, Byron; Wilder, Jennifer; Li, Feng; Miner, Jeffrey H.; Berg, Ulla B.; Smithies, Oliver

    2017-01-01

    How the kidney prevents urinary excretion of plasma proteins continues to be debated. Here, using unfixed whole-mount mouse kidneys, we show that fluorescent-tagged proteins and neutral dextrans permeate into the glomerular basement membrane (GBM), in general agreement with Ogston's 1958 equation describing how permeation into gels is related to molecular size. Electron-microscopic analyses of kidneys fixed seconds to hours after injecting gold-tagged albumin, negatively charged gold nanoparticles, and stable oligoclusters of gold nanoparticles show that permeation into the lamina densa of the GBM is size-sensitive. Nanoparticles comparable in size with IgG dimers do not permeate into it. IgG monomer-sized particles permeate to some extent. Albumin-sized particles permeate extensively into the lamina densa. Particles traversing the lamina densa tend to accumulate upstream of the podocyte glycocalyx that spans the slit, but none are observed upstream of the slit diaphragm. At low concentrations, ovalbumin-sized nanoparticles reach the primary filtrate, are captured by proximal tubule cells, and are endocytosed. At higher concentrations, tubular capture is saturated, and they reach the urine. In mouse models of Pierson’s or Alport’s proteinuric syndromes resulting from defects in GBM structural proteins (laminin β2 or collagen α3 IV), the GBM is irregularly swollen, the lamina densa is absent, and permeation is increased. Our observations indicate that size-dependent permeation into the lamina densa of the GBM and the podocyte glycocalyx, together with saturable tubular capture, determines which macromolecules reach the urine without the need to invoke direct size selection by the slit diaphragm. PMID:28246329

  12. Evidence for the existence of multiple heparan sulfate proteoglycans in the human glomerular basement membrane and mesangial matrix

    NARCIS (Netherlands)

    Groffen, Alexander J A; Hop, Frank W H; Tryggvason, Karl; Dijkman, Henri; Assmann, Karel J M; Veerkamp, Jacques H.; Monnens, Leo A H; Van Den Heuvel, Lambert P W J

    1997-01-01

    Heparan sulfate proteoglycans (HSPGs) are essential components of the glomerular basement membrane (GBM) carrying a strong anionic charge. A well- characterized extracellular HSPG is perlecan, ubiquitously expressed in basement membranes. A cDNA construct encoding domains I and II of human perlecan

  13. Antibody response against the glomerular basement membrane protein agrin in patients with transplant glomerulopathy.

    NARCIS (Netherlands)

    Joosten, S.A.; Sijpkens, Y.W.; Ham, V. van; Trouw, L.A.; Vlag, J. van der; Heuvel, L.P.W.J. van den; Kooten, C. van; Paul, L.C.

    2005-01-01

    Chronic allograft nephropathy (CAN) of renal allografts is still the most important cause of graft loss. A subset of these patients have transplant glomerulopathy (TGP), characterized by glomerular basement membrane (GBM) duplications, but of unknown etiology. Recently, a role for the immune system

  14. Basement membrane chondroitin sulfate proteoglycan alterations in a rat model of polycystic kidney disease

    DEFF Research Database (Denmark)

    Ehara, T; Carone, F A; McCarthy, K J

    1994-01-01

    Alterations in basement membrane components, notably proteoglycans, in a rat model of polycystic kidney disease have been investigated. Rats were fed phenol II (2-amino-4-hydroxyphenyl-5-phenyl thiazole) for 4 days and then changed to normal diet for a 7-day recovery period. Marked dilation of di...

  15. Macrophage Chemotaxis in Anti-tubular Basement Membrane-Induced Interstitial Nephritis in Guinea Pigs

    NARCIS (Netherlands)

    Kennedy, Thomas L.; Merrow, Martha; Phillips, S. Michael; Norman, Michael; Neilson, Eric G.

    1985-01-01

    Interstitial renal lesions containing T cells and macrophages develop after 14 days in guinea pigs immunized to produce anti-tubular basement membrane-induced interstitial nephritis. We serially examined the renal venous and systemic arterial sera from such animals to determine if chemotactic

  16. Spumiform capillary basement membrane swelling : A new type of microvascular degeneration in senescent hamster

    NARCIS (Netherlands)

    Gerrits, P.O.; Kortekaas, R.; de Weerd, H.; Veenstra-Algra, A.; Luiten, P.G.M.; van der Want, J.J.L.; Veening, Jan

    Brain microvasculature plays a critical role in the regulation of homeostasis of neural tissues. The present study focuses on characteristic microvascular basement membrane (bm) aberrations in the midbrain periaqueductal gray matter (PAG) and their relation to aging. The PAG can be considered a

  17. Spumiform capillary basement membrane swelling: a new type of microvascular degeneration in senescent hamster.

    NARCIS (Netherlands)

    Gerrits, P.O.; Kortekaas, R.; Weerd, H. de; Veenstra-Algra, A.; Luiten, P.G.M.; Want, J.J. van der; Veening, J.G.

    2013-01-01

    Brain microvasculature plays a critical role in the regulation of homeostasis of neural tissues. The present study focuses on characteristic microvascular basement membrane (bm) aberrations in the midbrain periaqueductal gray matter (PAG) and their relation to aging. The PAG can be considered a

  18. Deposition of nucleosomal antigens (histones and DNA) in the epidermal basement membrane in human lupus nephritis.

    NARCIS (Netherlands)

    Grootscholten, C.; Bruggen, M.C.J. van; Pijl, J.W. van der; Jong, E.M.G.J. de; Ligtenberg, G.; Derksen, R.H.W.M.; Berden, J.H.M.

    2003-01-01

    OBJECTIVE: Antinuclear autoantibodies complexed to nucleosomes can bind to heparan sulfate (HS) in the glomerular basement membrane. This binding is due to the binding of the positively charged histones to the strongly anionic HS. Nucleosomes and histones have been identified in glomerular deposits

  19. Co-deposition of basement membrane components during the induction of murine splenic AA amyloid

    DEFF Research Database (Denmark)

    Lyon, A W; Narindrasorasak, S; Young, I D

    1991-01-01

    Past studies have demonstrated that during murine AA amyloid induction there is co-deposition of the AA amyloid peptide and the basement membrane form of heparan sulfate proteoglycan. The synthesis and accumulation of heparan sulfate proteoglycan does not usually occur in the absence of other bas...

  20. Isotropic Versus Bipolar Functionalized Biomimetic Artificial Basement Membranes and Their Evaluation in Long-Term Human Cell Co-Culture.

    Science.gov (United States)

    Rossi, Angela; Wistlich, Laura; Heffels, Karl-Heinz; Walles, Heike; Groll, Jürgen

    2016-08-01

    In addition to dividing tissues into compartments, basement membranes are crucial as cell substrates and to regulate cellular behavior. The development of artificial basement membranes is indispensable for the ultimate formation of functional engineered tissues; however, pose a challenge due to their complex structure. Herein, biodegradable electrospun polyester meshes are presented, exhibiting isotropic or bipolar bioactivation as a biomimetic and biofunctional model of the natural basement membrane. In a one-step preparation process, reactive star-shaped prepolymer additives, which generate a hydrophilic fiber surface, are electrospun with cell-adhesion-mediating peptides, derived from major components of the basement membrane. Human skin cells adhere to the functionalized meshes, and long-term co-culture experiments confirm that the artificial basement membranes recapitulate and preserve tissue specific functions. Several layers of immortalized human keratinocytes grow on the membranes, differentiating toward the surface and expressing typical epithelial markers. Fibroblasts migrate into the reticular lamina mimicking part of the mesh. Both cells types begin to produce extracellular matrix proteins and to remodel the initial membrane. It is shown at the example of skin that the artificial basement membrane design provokes biomimetic responses of different cell types and can thus be used as basis for the future development of basement membrane containing tissues. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. [Collagen nephritis].

    Science.gov (United States)

    Lago, N R; Bulos, M J; Monserrat, A J

    1997-01-01

    Fibrillar collagen in the glomeruli is considered specific of the nail-patella syndrome. A new nephropathy with diffuse intraglomerular deposition of type III collagen without nail and skeletal abnormalities has been described. We report the case of a 26-year-old woman who presented persistent proteinuria, hematuria, deafness without nail and skeletal abnormalities. The renal biopsy showed focal and segmental glomerulosclerosis by light microscopy. The electron microscopy revealed the presence of massive fibrillar collagen within the mesangial matriz and the basement membrane. This is the first patient reported in our country. We emphasize the usefulness of electron microscopy in the study of glomerular diseases.

  2. The basement membrane constituents in the mouse embryo's tooth. An autoradiographic study

    International Nuclear Information System (INIS)

    Osman, M.

    1987-01-01

    Enamel organs isolated from the lower first teeth of 18-days old white mouse embryo by trypsin treatment were used in this study. The organs were cultured during periods of increasing time on a semi-solid medium containing cock serum. In another chase experiments, the organs were cultured on a liquid medium containing proline- 3 H, leucine- 3 H, and glucosamine- 3 H, were studied by autoradiography using both light and electron microscopes. It has been shown that the nature of the culture medium does not apparently interfere with the ability of the enamel to reconstitute the basement membrane. On the other hand, it have been found obvious differences concerning the kinetic of the used isotopes. The results indicate that the turn-over of the basement membrane constituents represents a continuous and homogenous process which continues to take place during, before and after reconstitution. 42 refs. (author)

  3. [Effect of collagenase on the permeability of the glomerular basement membrane in the rat kidney].

    Science.gov (United States)

    Laloi, C; Geloso-Meyer, A; Cheignon, M; Schaeverbeke, J

    1981-03-16

    Recently, several authors have emphasized the role of negative sites located in th laminae rarae of the glomerular basement membrane (GBM), in restricting glomerular permeability to anionic macromolecules. In this work, we point out that ultrafiltration properties involve integrity of the GBM. Indeed after intravenous perfusion of bacterian collagenase, anionic ferritin permeates the GBM though negative site distribution (as shown by fixation of colloidal iron) is unaffected.

  4. Normal mammary epithelial cells promote carcinoma basement membrane invasion by inducing microtubule-rich protrusions.

    Science.gov (United States)

    Lee, Meng-Horng; Wu, Pei-Hsun; Gilkes, Daniele; Aifuwa, Ivie; Wirtz, Denis

    2015-10-20

    Recent work suggests that the dissemination of tumor cells may occur in parallel with, and even preceed, tumor growth. The mechanism for this early invasion is largely unknown. Here, we find that mammary epithelial cells (MECs) induce neighboring breast carcinoma cells (BCCs) to cross the basement membrane by secreting soluble laminin. Laminin continuously produced by MECs induce long membrane cellular protrusions in BCCs that promote their contractility and invasion into the surrounding matrix. These protrusions depend on microtubule bundles assembled de novo through laminin-integrin β1 signaling. These results describe how non-cancerous MECs can actively participate in the invasive process of BCCs.

  5. Regeneration of the epidermis and basement membrane of the planarian Dugesia japonica after total-body x irradiation

    International Nuclear Information System (INIS)

    Hori, I.

    1979-01-01

    Fresh-water planarians were studied to examine effects of x rays on regeneration of the epidermis and basement membrane. During early stages of regeneration, free rhabdite-forming cells were associated with the wound epidermis and recruited it. In later stages, however, a gradual degeneration occurred in the epidermis and cells undergoing epithelization decreased in number. Eventually epidermal cells on the wound surface appeared necrotic as evidenced by pyknotic nuclei and vacuolized dense cytoplasm. The entire basement membrane could not be reconstituted in any stage after wounding though its precursor-like material was secreted in the interspace between epidermis and parenchyma. Morphological changes in extracellular products and in the cells surrounding the products suggest that epidermal cells which have covered the wound surface synthesize precursors of the basement membrane. Possible factors of a characteristic perturbation in epithelization and basement membrane formation after total-body irradiation are discussed

  6. Regeneration of the epidermis and basement membrane of the planarian Dugesia japonica after total-body x irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hori, I.

    1979-03-01

    Fresh-water planarians were studied to examine effects of x rays on regeneration of the epidermis and basement membrane. During early stages of regeneration, free rhabdite-forming cells were associated with the wound epidermis and recruited it. In later stages, however, a gradual degeneration occurred in the epidermis and cells undergoing epithelization decreased in number. Eventually epidermal cells on the wound surface appeared necrotic as evidenced by pyknotic nuclei and vacuolized dense cytoplasm. The entire basement membrane could not be reconstituted in any stage after wounding though its precursor-like material was secreted in the interspace between epidermis and parenchyma. Morphological changes in extracellular products and in the cells surrounding the products suggest that epidermal cells which have covered the wound surface synthesize precursors of the basement membrane. Possible factors of a characteristic perturbation in epithelization and basement membrane formation after total-body irradiation are discussed.

  7. Evaluation of nanohydroxyapaptite (nano-HA) coated epigallocatechin-3-gallate (EGCG) cross-linked collagen membranes.

    Science.gov (United States)

    Chu, Chenyu; Deng, Jia; Man, Yi; Qu, Yili

    2017-09-01

    Collagen is the main component of extracellular matrix (ECM) with desirable biological activities and low antigenicity. Collagen materials have been widely utilized in guided bone regeneration (GBR) surgery due to its abilities to maintain space for hard tissue growth. However, pure collagen lacks optimal mechanical properties. In our previous study, epigallocatechin-3-gallate (EGCG) cross-linked collagen membranes, with better biological activities and enhanced mechanical properties, may promote osteoblast proliferation, but their effect on osteoblast differentiation is not very significant. Nanohydroxyapatite (nano-HA) is the main component of mineral bone, which possesses exceptional bioactivity properties including good biocompatibility, high osteoconductivity and osteoinductivity, non-immunogenicity and non-inflammatory behavior. Herein, by analyzing the physical and chemical properties as well as the effects on promoting bone regeneration, we have attempted to present a novel EGCG-modified collagen membrane with nano-HA coating, and have found evidence that the novel collagen membrane may promote bone regeneration with a better surface morphology, without destroying collagen backbone. To evaluate the surface morphologies, chemical and mechanical properties of pure collagen membranes, epigallocatechin-3-gallate (EGCG) cross-linked collagen membranes, nano-HA coated collagen membranes, nano-HA coated EGCG-collagen membranes, (ii) to evaluate the bone regeneration promoted by theses membranes. In the present study, collagen membranes were divided into 4 groups: (1) untreated collagen membranes (2) EGCG cross-linked collagen membranes (3) nano-HA modified collagen membranes (4) nano-HA modified EGCG-collagen membranes. Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to evaluate surface morphologies and chemical properties, respectively. Mechanical properties were determined by differential scanning calorimeter (DSC

  8. Agar/collagen membrane as skin dressing for wounds

    International Nuclear Information System (INIS)

    Bao Lei; Yang Wei; Mao Xuan; Mou Shansong; Tang Shunqing

    2008-01-01

    Agar, a highly hydrophilic polymer, has a special gel property and favorable biocompatibility, but moderate intension strength in an aqueous condition and a low degradation rate. In order to tailor both properties of mechanical intension and degradation, type I collagen was composited with agar in a certain ratio by drying at 50 0 C or by a freeze-dry process. Glutaraldehyde was chosen as a crosslinking agent, and the most favorable condition for crosslinking was that the weight ratio of agar to glutaraldehyde was 66.7 and the pH value about 5. Dynamic mechanical analysis results showed that the single agar membrane had a modulus value between 640 MPa and 1064 MPa, but it was between 340 MPa and 819 MPa after being composited with type I collagen. It was discovered under an optical microscope that the pores were interconnected in the composite scaffolds instead of the honeycomb-like pores in a single type I collagen scaffold or the laminated gaps in a single agar scaffold. The results of an acute toxicity test disclosed that the composites were not toxic to mice although the composites were crosslinked with a certain concentration of glutaraldehyde. The results of gross examinations showed that when the composite membranes or scaffolds were applied to a repair rabbit skin lesion, the composites had a good repair effect without infection, liquid exudation or visible scar in the lesion covered with them. But in the control group, the autologous skin showed necrosis and there were a lot of scar tissues in the lesion site. H and E staining results showed that the repair tissue was similar to the normal one and very few scaffolds or membranes were left without degradation after 2 or 3 weeks. In conclusion, it is proved that type I collagen increases the toughness of the agar membrane, and the agar/type I collagen composites are promising biomaterials as wound dressings for healing burns or ulcers.

  9. Anti-glomerular basement membrane: A rare cause of renal failure in children

    Directory of Open Access Journals (Sweden)

    Indira Agarwal

    2017-01-01

    Full Text Available Anti-glomerular basement membrane (GBM disease is a rare cause of acute renal failure and known to have bad prognosis regarding renal functions recovery and patient survival specially when diagnosed late and presents with severe renal failure that requires dialysis. We report a case of 11-year-old child with acute renal failure secondary to anti-GBM disease and associated with antineutrophil cytoplasmic antibody-positive vasculitis. He was treated with plasmapheresis, steroids, and cyclophosphamide with recovery of his kidney functions.

  10. Basement membrane heparan sulfate proteoglycan from the L2 rat yolk sac carcinoma

    DEFF Research Database (Denmark)

    Fenger, M; Wewer, U; Albrechtsen, R

    1984-01-01

    Heparan sulfate proteoglycan from the L2 rat yolk sac carcinoma has been purified and partially characterized. The proteoglycan has an apparent Mr of 750 000, 35% of which represents the core protein. The core protein seems to be homogeneous, whereas the heparan sulfate chains are heterogeneous...... with an Mr of about 50 000-70 000, with 30% of the glucosamine being N-sulfated. Antibodies raised against the core protein of the heparan sulfate proteoglycan reacted with basement membranes of various rat and human tissue....

  11. Immunochemical and ultrastructural assessment of the nature of the pericellular basement membrane of human decidual cells

    DEFF Research Database (Denmark)

    Wewer, U M; Faber, M; Liotta, L A

    1985-01-01

    Human decidual cells of early and late pregnancy were studied immunochemically and ultrastructurally with respect to the presence and nature of pericellular basement membrane material. The most prominent cell type in decidual tissue of both early and late pregnancy were large, mature epithelioid...... of stromal cells into decidual cells of the pregnant endometrium. Predecidualization of the human endometrium, which is seen in the late secretory phase of the normal menstrual cycle and in some states of hyperplasia, was also shown to be accompanied by the presence of deposits of laminin-positive material...

  12. In vivo turnover of the basement membrane and other heparan sulfate proteoglycans of rat glomerulus

    DEFF Research Database (Denmark)

    Beavan, L A; Davies, M; Couchman, J R

    1989-01-01

    The metabolic turnover of rat glomerular proteoglycans in vivo was investigated. Newly synthesized proteoglycans were labeled during a 7-h period after injecting sodium [35S]sulfate intraperitoneally. At the end of the labeling period a chase dose of sodium sulfate was given. Subsequently......-propanesulfonate-4 M guanidine hydrochloride, a procedure which solubilized greater than 95% of the 35S-labeled macromolecules. Of these 11-13% was immunoprecipitated by an antiserum against heparan sulfate proteoglycan which, in immunolocalization experiments, showed specificity for staining the basement membrane...

  13. Increasingly transformed MCF-10A cells have a progressively tumor-like phenotype in three-dimensional basement membrane culture.

    Science.gov (United States)

    Imbalzano, Karen M; Tatarkova, Iva; Imbalzano, Anthony N; Nickerson, Jeffrey A

    2009-03-16

    MCF-10A cells are near diploid and normal human mammary epithelial cells. In three-dimensional reconstituted basement membrane culture, they undergo a well-defined program of proliferation, differentiation, and growth arrest, forming acinar structures that recapitulate many aspects of mammary architecture in vivo. The pre-malignant MCF-10AT cells and malignant MCF-10CA1a lines were sequentially derived from the MCF-10A parental cell line first by expression of a constitutively active T24 H-Ras generating the MCF-10AT cell line. This was followed by repeated selection for increasingly aggressive tumor formation from cells recovered from xenograft tumors in immuno-compromised mice, generating the MCF-10CA1a cell line. When inoculated subcutaneously into the flanks of immuno-compromised mice, MCF-10AT cells occasionally form tumors, whereas MCF-10CA1a cells invariably form tumors with a shorter latency than MCF-10AT derived tumors. MCF-10AT cells grown in three-dimensional basement membrane culture form complex multi-acinar structures that produce a basement membrane but undergo delayed cell cycle arrest and have incomplete luminal development. MCF-10CA1a cells grown in three-dimensional basement membrane culture form large, hyper-proliferative masses, that retain few characteristics of MCF10A acini and more closely resemble tumors. Here we report on the growth and differentiation properties of these three matched cell lines in three-dimensional basement membrane culture. Features of tissue morphogenesis were assessed, including proliferation, basement membrane formation, polarization of alpha-6 beta-4 integrin to the basement membrane, formation of cell:cell junctions, and apoptosis for luminal clearance. The matched series of normal MCF-10A, pre-malignant MCF-10AT, and malignant MCF-10CA1a cells offers a unique opportunity to study the mechanisms of malignant progression both in a three-dimensional microenvironment and in the same cell background.

  14. The chest X-ray in antiglomerular basement membrane antibody disease (Goodpasture's syndrome)

    International Nuclear Information System (INIS)

    Bowley, N.B.; Steiner, R.E.; Chin, W.S.

    1979-01-01

    The chest radiographs of 25 patients with proven antiglomerular basement membrane antibody disease (Goodpasture's syndrome) were analysed. All except two of the patients had pulmonary haemorrhage at some stage of their disease. Altogether there were 39 episodes of pulmonary haemorrhage, 25 being relapses. During seven episodes the chest radiograph was normal. Relapses of pulmonary haemorrhage never occurred in isolation but were usually associated with infection (not necessarily a chest infection) or occasionally fluid overload. Conversely fluid overload or infection were always associated with pulmonary haemorrhage provided there were high or rising titres of circulating antibodies at the time. Therefore in a patient with antiglomerular basement membrane antibody disease, the presence of shadowing in the lung fields on the chest radiograph almost invariably means the patient has pulmonary haemorrhage whether or not pulmonary oedema or a chest infection are present. Limitation of shadowing by a fissure, loss of major portions of the diaphragmatic or cardiac silhouette, involvement of the lung apex or costophrenic angles suggest an underlying chest infection. Septal lines suggest fluid overload. Pleural effusions are seen with chest infections and fluid overload. The carbon monoxide uptake (KCO) was invariably high in the presence of pulmonary haemorrhage even if the chest radiograph was normal. A combined use of KCO and chest radiographs is the best method of monitoring lung disease in these patients. (author)

  15. Effect of diabetes on in vivo metabolism of [35S]-labeled glomerular basement membrane

    International Nuclear Information System (INIS)

    Cohen, M.P.; Surma, M.L.

    1984-01-01

    Glomerular basement membrane (GBM) was labeled in vivo by the injection of tracer amounts of [ 35 S]-sulfate into normal and streptozotocin-diabetic rats. The biosynthesis and turnover of sulfated glycosaminoglycans in the GBM was determined from the specific activity of [ 35 S] after pronase digestion of basement membranes purified from glomeruli isolated 1-7 days after injection. Peak radiolabeling of both normal and diabetic GBM occurred 24 h after injection and, when corrected for differences in serum sulfate specific activities, was less in diabetic than in normal samples. The specific activity of GBM sulfate, expressed as cpm/microgram uronic acid, progressively diminished over the ensuing period of study in both normal and diabetic samples. The rate of decrease in specific activity of [ 35 S]-labeled GBM was not significantly different in diabetic preparations compared with that in normal controls. The findings are compatible with diminished sulfation and/or production but normal turnover of glycosaminoglycans in the renal GBM in experimental diabetes

  16. Specific fixation of bovine brain and retinal acidic and basic fibroblast growth factors to mouse embryonic eye basement membranes

    International Nuclear Information System (INIS)

    Jeanny, J.C.; Fayein, N.; Courtois, Y.; Moenner, M.; Chevallier, B.; Barritault, D.

    1987-01-01

    The labeling pattern of mouse embryonic eye frozen sections incubated with radioiodinated brain acidic and basic fibroblasts growth factors (aFGF and bFGF) was investigated by autoradiography. Both growth factors bind to basement membranes in a dose-dependent way, with a higher affinity for bFGF. Similar data were obtained with eye-derived growth factors (EDGF), the retinal forms of FGF. There was a heterogeneity in the affinity of the various basement membranes toward these growth factors. The specificity of the growth factor-basement membrane interaction was demonstrated by the following experiments: (i) an excess of unlabeled growth factor displaced the labeling; (ii) unrelated proteins with different isoelectric points did not modify the labeling; and (iii) iodinated EGF or PDGF did not label basement membrane. In order to get a better understanding of the nature of this binding, the authors performed the incubation of the frozen sections with iodinated FGFs preincubated with various compounds. These results demonstrate that FGFs bind specifically to basement membranes, probably on the polysaccharidic part of the proteoheparan sulfate, and suggest that this type of interaction may be a general feature of the mechanism of action of these growth factors

  17. Laminin, a noncollagenous component of epithelial basement membranes synthesized by a rat yolk sac tumor

    DEFF Research Database (Denmark)

    Wewer, U; Albrechtsen, R; Ruoslahti, E

    1981-01-01

    Laminin, a glycoprotein antigenically similar or identical to a component of epithelial basement membranes, was identified as a major component of the abundant extracellular matrix synthesized by an experimentally induced rat yolk sac tumor. Immunocytochemical staining revealed laminin in cultured...... polypeptides with molecular weights of approximately 200,000 and 400,000. These comigrated with the polypeptides of mouse laminin isolated previously. The yolk sac tumor tissue grown in vivo contained laminin in the tumor cells and in the extracellular material as evidenced by immunofluorescence...... membranes in rat tissues in a manner indistinguishable from antilaminin. The presence of laminin in rat yolk sac cells, the presumed origin of our yolk sac tumor, was studied in some detail. Laminin was found to be present in normal cells of the visceral as well as the parietal yolk sac layer...

  18. Human skin basement membrane-associated heparan sulphate proteoglycan: distinctive differences in ultrastructural localization as a function of developmental age

    DEFF Research Database (Denmark)

    Horiguchi, Y; Fine, J D; Couchman, J R

    1991-01-01

    Recent studies have demonstrated that skin basement membrane components are expressed within the dermo-epidermal junction in an orderly sequence during human foetal development. We have investigated the ultrastructural localization of basement membrane-related antigens in human foetal skin...... at different developmental ages using two monoclonal antibodies to a well-characterized basement membrane-associated heparan sulphate proteoglycan. A series of foetal skin specimens (range, 54-142 gestational days) were examined using an immunoperoxidase immunoelectron microscopic technique. In specimens...... representing very early developmental ages, very diffuse immunoreaction products were detected. However, by approximately 76 gestational days, some accentuation of heparan sulphate proteoglycan was noted along the lamina densa, and by 142 gestational days, the distribution of heparan sulphate proteoglycan...

  19. Nephritogenic antigen determinants in epidermal and renal basement membranes of kindreds with Alport-type familial nephritis.

    OpenAIRE

    Kashtan, C; Fish, A J; Kleppel, M; Yoshioka, K; Michael, A F

    1986-01-01

    We probed epidermal basement membranes (EBM) of acid-urea denatured skin from members of kindreds with Alport-type familial nephritis (FN) for the presence of antigens reactive with Goodpasture sera (GPS) and serum (FNS) from an Alport patient who developed anti-glomerular basement membrane (GBM) nephritis in a renal allograft. By immunoblotting, GPS reacted primarily with the 28,000 molecular weight (mol wt) monomer but also the 24,000 mol wt and 26,000 mol wt monomers of the noncollagenous ...

  20. Cell Receptor-Basement Membrane Interactions in Health and Disease: a Kidney-Centric View

    Science.gov (United States)

    Borza, Corina M.; Chen, Xiwu; Zent, Roy; Pozzi, Ambra

    2016-01-01

    Cell-extracellular matrix (ECM) interactions are essential for tissue development, homeostasis, and response to injury. Basement membranes (BMs) are specialized ECMs that separate epithelial or endothelial cells from stromal components and interact with cells via cellular receptors, including integrins and discoidin domain receptors. Disruption of cell-BM interactions due to either injury or genetic defects in either the ECM components or cellular receptors often lead to irreversible tissue injury and loss of organ function. Animal models that lack specific BM components or receptors either globally or in selective tissues have been used to help with our understanding of the molecular mechanisms whereby cell-BM interactions regulate organ function in physiological and pathological conditions. We review recently published work on animal models that explore how cell-BM interactions regulate kidney homeostasis in both health and disease. PMID:26610916

  1. Heterogeneous distribution of a basement membrane heparan sulfate proteoglycan in rat tissues

    DEFF Research Database (Denmark)

    Couchman, J R

    1987-01-01

    A heparan sulfate proteoglycan (HSPG) synthesized by murine parietal yolk sac (PYS-2) cells has been characterized and purified from culture supernatants. A monospecific polyclonal antiserum was raised against it which showed activity against the HSPG core protein and basement membrane specificity...... for multiple HSPGs was derived from the finding that skeletal neuromuscular junction and liver epithelia also did not contain this type of HSPG, though previous reports have indicated the presence of HSPGs at these sites. The PYS-2 HSPG was shown to be antigenically related to the large, low buoyant density...... HSPG from the murine Engelbreth-Holm swarm tumor. It was, however, confirmed that only a single population of antibodies was present in the serum. Despite the presence of similar epitopes on these two proteoglycans of different hydrodynamic properties, it was apparent that the PYS-2 HSPG represents...

  2. Antiglomerular basement membrane antibody-mediated glomerulonephritis after intranasal cocaine use.

    Science.gov (United States)

    Peces, R; Navascués, R A; Baltar, J; Seco, M; Alvarez, J

    1999-01-01

    We report a case of rapidly progressive glomerulonephritis due to antiglomerular basement membrane (anti-GBM) antibodies that progressed to end-stage renal disease in a 35-year-old man who used intranasal cocaine on an occasional basis. In contrast to many prior reports of acute renal failure occurring with cocaine-associated rhabdomyolysis, this patient did not have any evidence of acute muscle damage and myoglobin release. Circulating anti-GBM antibodies and renal biopsy with linear IgG and C3 deposits confirmed the diagnosis of anti-GBM disease. The possibility of anti-GBM must be considered in the differential diagnosis of acute renal failure in cocaine addicts. This unusual combination raises complex questions regarding the pathogenesis of this type of renal injury.

  3. Clinical outcome of patients with coexistent antineutrophil cytoplasmic antibodies and antibodies against glomerular basement membrane.

    Science.gov (United States)

    Lindic, Jelka; Vizjak, Alenka; Ferluga, Dusan; Kovac, Damjan; Ales, Andreja; Kveder, Radoslav; Ponikvar, Rafael; Bren, Andrej

    2009-08-01

    Antineutrophil cytoplasmic antibodies (ANCA) and antibodies against glomerular basement membrane (anti-GBM) rarely coexist. Both antibodies may be associated with rapidly progressive glomerulonephritis and pulmonary hemorrhage. We describe the clinical, serological and histological features of our patients with dual antibodies. From 1977 to 2008, 48 patients with anti-GBM antibody-associated renal disease were observed. Eight out of the 30 tested patients (26.7%), all females, had positive myeloperoxidase (MPO)-ANCA coexistent with anti-GBM antibodies. The patients' mean age was 63.4 +/- 7.8 years. Five presented with pulmonary-renal syndrome, all but one were dialysis-dependent on admission. They had constitutional symptoms and different organ involvement. The kidney biopsies revealed intense linear staining for immunoglobulin G and C3 along the glomerular and distal tubular basement membrane associated with irregular diffuse or focal extracapillary crescentic glomerulonephritis with necrosis of varying extent. Lesions of varying ages were characteristically expressed. Seven patients were treated with methylprednisolone and plasma exchange, four with cyclophosphamide, and one with intravenous immunoglobulin. After 28-74 months, there were three dialysis-dependent survivors and one patient with stable chronic renal disease. Two clinical relapses with pulmonary involvement and MPO-ANCA positivity without anti-GBM antibodies occurred in two dialysis-dependent patients. In summary, screening for ANCA and anti-GBM antibodies should be undertaken in patients with clinical signs of systemic vasculitis. In dialysis-dependent patients, the goal of treatment is to limit the damage of other involved organs and not to preserve renal function. Careful follow-up is necessary due to the relapsing nature of the ANCA component of the disease.

  4. Therapeutic Mechanism of Glucocorticoids on Cellular Crescent Formation in Patients With Antiglomerular Basement Membrane Disease.

    Science.gov (United States)

    Wu, Xiaomei; Zhang, Mingchao; Huang, Xiao; Zhang, Lihua; Zeng, Caihong; Zhang, Jiong; Liu, Zhihong; Tang, Zheng

    2017-08-01

    This study aimed to explore the therapeutic mechanism of glucocorticoids (GCs) in antiglomerular basement membrane disease. Thirty-four patients with biopsy-proven antiglomerular basement membrane nephritis were divided into the following 2 groups: group 1 (patients treated with GCs, n = 22) and group 2 (patients who were not treated with GCs, n = 12). The expression of parietal epithelial cells (PECs), activated PECs and glucocorticoid receptors (GRs) was examined quantitatively and compared between the 2 groups. Correlations between GR expression in glomeruli and patients' clinicopathological indices were also analyzed. Compared with patients in group 2, patients in group 1 showed lower levels of serum creatinine (SCr) (P = 0.03), average cellular crescent percentage (P = 0.005) and macrophages infiltrating in renal interstitium (P = 0.03). PECs (P = 0.007) and activated PECs (P = 0.03) were strongly detected in the cellular components of classic crescents, and both were significantly reduced in group 1 compared to group 2. GR expression either in glomeruli (P = 0.01) or interstitium (P = 0.009) was lower in group 1 after GCs treatment than in group 2. Additionally, GR expression in glomeruli was strongly correlated with renal function (SCr: r = 0.45, P = 0.009; eGFR: r = -0.35, P = 0.046), the proportion of cellular crescents (r = 0.67, P < 0.001), PECs (r = 0.64, P < 0.001) and activated PECs (r = 0.72, P < 0.001), and the degree of interstitial (r = 0.50, P = 0.004) and glomerular (r = 0.49, P = 0.007) macrophage infiltration. GCs might exert their therapeutic effects via inhibiting the activation and proliferation of PECs, as well as macrophage infiltration, which could contribute to crescent formation and determine renal survival. GRs are involved in this process as well. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

  5. Cloning and chromosomal mapping of mouse ladinin, a novel basement membrane zone component

    Energy Technology Data Exchange (ETDEWEB)

    Motoki, K.; Megahed, M.; LaForgia, S.; Uitto, J. [Thomas Jefferson Univ., Philadelphia, PA (United States)

    1997-02-01

    Linear IgA disease is characterized by circulating IgA autoantibodies recognizing basement membrane zone components, including an anchoring filament protein, ladinin. In this study, we have cloned the mouse ladinin cDNA, elucidated the intron-exon organization of the corresponding gene (Lad1), and determined its chromosomal assignment. We have also characterized the promoter region of Lad1 and examined its tissue-specific expression. The mouse Lad1 gene consists of 10 exons spanning {approximately}13.4 kb of the mouse genome on chromosome 1, and Southern analysis suggested that Lad1 is a single-copy gene. The coding region comprises 1584 nucleotides and encodes a 528-amino-acid polypeptide with a calculated molecular mass of 59 kDa. The deduced polypeptide contained two putative N-glycosylation and two O-glycosylation sites, and sequence analysis predicted a 15-amino-acid signal peptide. The 5{prime} upstream region demonstrated the presence of consensus cis-elements for AP2 and SP1 and was GC rich, consistent with eukaryotic promoter. Northern analysis revealed expression in cultured keratinocytes, but not in fibroblasts, with the mRNA transcript being {approximately}2.5 kb in size. A significant level of expression was also noted in the kidney and lung, and to a lesser degree in the liver, spleen, and brain. Ladinin is a novel component of the basement membranes and may function in contributing to the stability of the association of the epithelial layers with the underlying mesenchyme. 39 refs., 4 figs.

  6. [3H]glucosamine and [3H]proline radioautography of embryonic mouse dental basement membrane

    International Nuclear Information System (INIS)

    Osman, M.; Ruch, J.V.

    1981-01-01

    [ 3 H]proline and [ 3 H]glucosamine radioautography was performed to analyze the labeling pattern of mouse embryonic dental basement membrane before and during odontoblast terminal differentiation. Sixteen- and eighteen-day-old first lower molars and trypsin-isolated enamel organs, as well as EDTA-isolated dental papillae, were used. Continuous labeling for 12 to 24 hr was required with [ 3 H]proline to obtain a clear labeling of epithelial-mesenchymal junction in intact tooth germs or accumulation of surface label in trypsin-isolated enamel organs. With [ 3 H]glucosamine, after 6-hr labeling, the epithelial-mesenchymal junction was heavily labeled and the trypsin-isolated enamel organs accumulated substantial amounts of surface label, corresponding to the redeposited basement membrane. At Day 16 stage, these labels always had a uniform distribution and decreased during chase without any redistribution. At Day 18 stage, when the terminal differentiation of odontoblasts occurred the label accumulated in a unique pattern: much more label was at the epithelial surface corresponding to the top of the cusps than in the apical parts. During chase and only in intact tooth germs epithelial surfaces which had labeled poorly during pulse became labeled, but those labeling heavily during pulse lost label. This pattern existed only in the presence of mesenchyme. EDTA treatment of [ 3 H]glucosamine-labeled teeth enabled us to obtain isolated dental papillae with surface label. Distribution of this label was exactly the same as that for the epithelial-mesenchymal junction of intact teeth. During chase, these dental papillae completely lost the surface label. The mesenchyme seen to control the synthesis and/or the degradation of epithelially derived [ 3 H]glucosamine-labeled material

  7. In vivo turnover of the basement membrane and other heparan sulfate proteoglycans of rat glomerulus

    International Nuclear Information System (INIS)

    Beavan, L.A.; Davies, M.; Couchman, J.R.; Williams, M.A.; Mason, R.M.

    1989-01-01

    The metabolic turnover of rat glomerular proteoglycans in vivo was investigated. Newly synthesized proteoglycans were labeled during a 7-h period after injecting sodium [35S]sulfate intraperitoneally. At the end of the labeling period a chase dose of sodium sulfate was given. Subsequently at defined times (0-163 h) the kidneys were perfused in situ with 0.01% cetylpyridinium chloride in phosphate-buffered saline to maximize the recovery of 35S-proteoglycans. Glomeruli were isolated from the renal cortex and analyzed for 35S-proteoglycans by autoradiographic, biochemical, and immunochemical methods. Grain counting of autoradiographs revealed a complex turnover pattern of 35S-labeled macromolecules, commencing with a rapid phase followed by a slower phase. Biochemical analysis confirmed the biphasic pattern and showed that the total population of [35S]heparan sulfate proteoglycans had a metabolic half-life (t1/2) of 20 and 60 h in the early and late phases, respectively. Heparan sulfate proteoglycans accounted for 80% of total 35S-proteoglycans, the remainder being chondroitin/dermatan sulfate proteoglycans. Whole glomeruli were extracted with 4% 3-[(cholamidopropyl)dimethy-lammonio]-1-propanesulfonate-4 M guanidine hydrochloride, a procedure which solubilized greater than 95% of the 35S-labeled macromolecules. Of these 11-13% was immunoprecipitated by an antiserum against heparan sulfate proteoglycan which, in immunolocalization experiments, showed specificity for staining the basement membrane of rat glomeruli. Autoradiographic analysis showed that 18% of total radioactivity present at the end of the labeling period was associated with the glomerular basement membrane

  8. Normal and tumor-derived myoepithelial cells differ in their ability to interact with luminal breast epithelial cells for polarity and basement membrane deposition

    Energy Technology Data Exchange (ETDEWEB)

    Gudjonsson, Thorarinn; Ronnov-Jessen, Lone; Villadsen, Rene; Rank, Fritz; Bissell, Mina J.; Petersen, Ole William

    2001-10-04

    The signals that determine the correct polarity of breast epithelial structures in vivo are not understood. We have shown previously that luminal epithelial cells can be polarized when cultured within a reconstituted basement membrane gel. We reasoned that such cues in vivo may be given by myoepithelial cells. Accordingly, we used an assay where luminal epithelial cells are incorrectly polarized to test this hypothesis. We show that culturing human primary luminal epithelial cells within collagen-I gels leads to formation of structures with no lumina and with reverse polarity as judged by dual stainings for sialomucin, epithelial specific antigen or occludin. No basement membrane is deposited, and {beta}4-integrin staining is negative. Addition of purified human myoepithelial cells isolated from normal glands corrects the inverse polarity, and leads to formation of double-layered acini with central lumina. Among the laminins present in the human breast basement membrane (laminin-1, -5 and -10/11), laminin-1 was unique in its ability to substitute for myoepithelial cells in polarity reversal. Myoepithelial cells were purified also from four different breast cancer sources including a biphasic cell line. Three out of four samples either totally lacked the ability to interact with luminal epithelial cells, or conveyed only correction of polarity in a fraction of acini. This behavior was directly related to the ability of the tumor myoepithelial cells to produce {alpha}-1 chain of laminin. In vivo, breast carcinomas were either negative for laminin-1 (7/12 biopsies) or showed a focal, fragmented deposition of a less intensely stained basement membrane (5/12 biopsies). Dual staining with myoepithelial markers revealed that tumorassociated myoepithelial cells were either negative or weakly positive for expression of laminin-1, establishing a strong correlation between loss of laminin-1 and breast cancer. We conclude that the double-layered breast acinus may be

  9. The Peri-islet Basement Membrane, a Barrier to Infiltrating Leukocytes in Type 1 Diabetes in Mouse and Human

    DEFF Research Database (Denmark)

    Korpos, Eva; Kadri, Nadir; Kappelhoff, Reinhild

    2013-01-01

    We provide the first comprehensive analysis of the extracellular matrix (ECM) composition of peri-islet capsules, composed of the peri-islet basement membrane (BM) and subjacent interstitial matrix (IM), in development of type 1 diabetes in NOD mice and in human type 1 diabetes. Our data demonstr...

  10. Distribution of two basement membrane proteoglycans through hair follicle development and the hair growth cycle in the rat

    DEFF Research Database (Denmark)

    Couchman, J R; King, J L; McCarthy, K J

    1990-01-01

    The distribution of two distinct populations of basement membrane proteoglycans has been monitored through hair growth development in the rat embryo and subsequent hair growth cycle. An antiserum against a small heparan sulfate proteoglycan uniformly stained the dermal-epidermal junction of embry...

  11. Electron microscopic study of the myelinated nerve fibres and the perineurial cell basement membrane in the diabetic human peripheral nerves

    International Nuclear Information System (INIS)

    ElBarrany, Wagih G.; Hamdy, Raid M.; AlHayani, Abdulmonem A.; Jalalah, Sawsan M.

    2009-01-01

    To study the quantitative and ultrastructural changes in myelinated nerve fibers and the basement membranes of the perineurial cells in diabetic nerves. The study was performed at the Department of Anatomy, Faculty of Medicine, King Abdul-Aziz University, Jeddah, Saudi Arabia from 2003 to 2005. Human sural nerves were obtained from 15 lower limbs and 5 diabetic nerve biopsies. The total mean and density of myelinated nerve fibers per fascicle were calculated, with density of microtubules and mitochondria in the axoplasm. The number of the perineurial cell basement membrane layers was counted, and thickness of the basement membrane was measured. Among the 15 diabetic and 5 normal human sural nerves, the average diameters, number and surface area of myelinated nerve fibers and axonal microtubules density were found to be less in diabetic nerves. Mitochondrial density was higher in diabetic axons. Thickness of the perineurial cell basement membrane had a greater mean, but the number of perineurial cell layers was less than that of the diabetic group. The inner cellular layer of the perineurium of the diabetic nerves contained large vacuoles containing electron-dense degenerated myelin. A few specimens showed degenerated myelinated nerve fibers, while others showed recovering ones. Retracted axoplasms were encountered with albumin extravasation. Diabetes caused an increase in perineurial permeability. The diabetic sural nerve showed marked decrease in the myelinated nerve fibres, increase degenerated mitochondria, and decreased microtubules. (author)

  12. Spumiform basement membrane aberrations in the microvasculature of the midbrain periaqueductal gray region in hamster : Rostro-caudal pathogenesis?

    NARCIS (Netherlands)

    Gerrits, P.O.; Kortekaas, R.; de Weerd, Heleen; Luiten, P.G.M.; van der Want, J.J.L.; Veening, Jan

    2013-01-01

    Spumiform basement membrane degeneration (sbmd) is a specific kind of aberration present in the capillaries of the midbrain periaqueductal gray (PAG) region of the senescent hamster. These capillaries, separated by the ependymal cell layer, are bordering the Sylvian cerebral aqueduct. The aqueduct,

  13. Spumiform basement membrane aberrations in the microvasculature of the midbrain periaqueductal gray region in hamster: rostro-caudal pathogenesis?

    NARCIS (Netherlands)

    Gerrits, P.O.; Kortekaas, R.; Weerd, H. de; Luiten, P.G.M.; Want, J.J. van der; Veening, J.G.

    2013-01-01

    Spumiform basement membrane degeneration (sbmd) is a specific kind of aberration present in the capillaries of the midbrain periaqueductal gray (PAG) region of the senescent hamster. These capillaries, separated by the ependymal cell layer, are bordering the Sylvian cerebral aqueduct. The aqueduct,

  14. Ultrastructural localization of the core protein of a basement membrane-specific chondroitin sulfate proteoglycan in adult rat skin

    DEFF Research Database (Denmark)

    McCarthy, K J; Horiguchi, Y; Couchman, J R

    1990-01-01

    , fibronectin, and entactin/nidogen. IN this paper we show, using core protein-specific antibodies, the presence of a newly described basement membrane-specific chondroitin sulfate proteoglycan at the epithelial/mesenchymal interface of adult rat skin. Ultrastructurally, this antigen was proven to reside...

  15. Increasingly transformed MCF-10A cells have a progressively tumor-like phenotype in three-dimensional basement membrane culture

    Directory of Open Access Journals (Sweden)

    Imbalzano Anthony N

    2009-03-01

    Full Text Available Abstract Background MCF-10A cells are near diploid and normal human mammary epithelial cells. In three-dimensional reconstituted basement membrane culture, they undergo a well-defined program of proliferation, differentiation, and growth arrest, forming acinar structures that recapitulate many aspects of mammary architecture in vivo. The pre-malignant MCF-10AT cells and malignant MCF-10CA1a lines were sequentially derived from the MCF-10A parental cell line first by expression of a constitutively active T24 H-Ras generating the MCF-10AT cell line. This was followed by repeated selection for increasingly aggressive tumor formation from cells recovered from xenograft tumors in immuno-compromised mice, generating the MCF-10CA1a cell line. When inoculated subcutaneously into the flanks of immuno-compromised mice, MCF-10AT cells occasionally form tumors, whereas MCF-10CA1a cells invariably form tumors with a shorter latency than MCF-10AT derived tumors. Results MCF-10AT cells grown in three-dimensional basement membrane culture form complex multi-acinar structures that produce a basement membrane but undergo delayed cell cycle arrest and have incomplete luminal development. MCF-10CA1a cells grown in three-dimensional basement membrane culture form large, hyper-proliferative masses, that retain few characteristics of MCF10A acini and more closely resemble tumors. Conclusion Here we report on the growth and differentiation properties of these three matched cell lines in three-dimensional basement membrane culture. Features of tissue morphogenesis were assessed, including proliferation, basement membrane formation, polarization of alpha-6 beta-4 integrin to the basement membrane, formation of cell:cell junctions, and apoptosis for luminal clearance. The matched series of normal MCF-10A, pre-malignant MCF-10AT, and malignant MCF-10CA1a cells offers a unique opportunity to study the mechanisms of malignant progression both in a three

  16. Functional differentiation and alveolar morphogenesis of primary mammary cultures on reconstituted basement membrane

    Energy Technology Data Exchange (ETDEWEB)

    BARCELLOS-HOFF, M. H; AGGELER, J.; RAM, T. G; BISSELL, M. J

    1989-02-01

    An essential feature of mammary gland differentiation during pregnancy is the formation of alveoli composed of polarized epithelial cells, which, under the influence of lactogenic hormones, secrete vectorially and sequester milk proteins. Previous culture studies have described either organization of cells polarized towards lumina containing little or no demonstrable tissue-specific protein, or establishment of functional secretory cells exhibiting little or no glandular architecture. In this paper, we report that tissue-specific vectorial secretion coincides with the formation of functional alveoli-like structures by primary mammary epithelial cells cultured on a reconstituted basement membrane matrix (derived from Engelbreth-Holm-Swarm murine tumour). Morphogenesis of these unique three-dimensional structures was initiated by cell-directed remodelling of the exogenous matrix leading to reorganization of cells into matrixensheathed aggregates by 24 h after plating. The aggregates subsequently cavitated, so that by day 6 the cells were organized into hollow spheres in which apical cell surfaces faced lumina sealed by tight junctions and basal surfaces were surrounded by a distinct basal lamina. The profiles of proteins secreted into the apical (luminal) and basal (medium) compartments indicated that these alveoli-like structures were capable of an appreciable amount of vectorial secretion. Immunoprecipitation with a broad spectrum milk antiserum showed that more than 80% of caseins were secreted into the lumina, whereas iron-binding proteins (both lactoferrin and transferrin) were present in comparable amounts in each compartment. Thus, these mammary cells established protein targeting pathways directing milk-specific proteins to the luminal compartment. A time course monitoring secretory activity demonstrated that establishment of tissue-specific vectorial secretion and increased total and milk protein secretion coincided with functional alveolar

  17. Evaluation of epigallocatechin-3-gallate (EGCG) cross-linked collagen membranes and concerns on osteoblasts

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Chenyu; Deng, Jia [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Xiang, Lin; Wu, Yingying [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Wei, Xiawei [State Key Laboratory of Biotherapy and Laboratory for Aging Research, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041 (China); Qu, Yili [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Man, Yi, E-mail: manyi780203@126.com [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China)

    2016-10-01

    Collagen membranes have ideal biological and mechanical properties for supporting infiltration and proliferation of osteoblasts and play a vital role in guided bone regeneration (GBR). However, pure collagen can lead to inflammation, resulting in progressive bone resorption. Therefore, a method for regulating the level of inflammatory cytokines at surgical sites is paramount for the healing process. Epigallocatechin-3-gallate (EGCG) is a component extracted from green tea with numerous biological activities including an anti-inflammatory effect. Herein, we present a novel cross-linked collagen membrane containing different concentrations of EGCG (0.0064%, 0.064%, and 0.64%) to regulate the level of inflammatory factors secreted by pre-osteoblast cells; improve cell proliferation; and increase the tensile strength, wettability, and thermal stability of collagen membranes. Scanning electron microscope images show that the surfaces of collagen membranes became smoother and the collagen fiber diameters became larger with EGCG treatment. Measurement of the water contact angle demonstrated that introducing EGCG improved membrane wettability. Fourier transform infrared spectroscopy analyses indicated that the backbone of collagen was intact, and the thermal stability was significant improved in differential scanning calorimetry. The mechanical properties of 0.064% and 0.64% EGCG-treated collagen membranes were 1.5-fold greater than those of the control. The extent of cross-linking was significantly increased, as determined by a 2,4,6-trinitrobenzenesulfonic acid solution assay. The Cell Counting Kit-8 (CCK-8) and live/dead assays revealed that collagen membrane cross-linked by 0.0064% EGCG induced greater cell proliferation than pure collagen membranes. Additionally, real-time polymerase chain reaction and enzyme-linked immunosorbent assay results showed that EGCG significantly affected the production of inflammatory factors secreted by MC3T3-E1 cells. Taken together, our

  18. Crosslinked basement membrane-based coatings enhance glucose sensor function and continuous glucose monitoring in vivo.

    Science.gov (United States)

    Klueh, Ulrike; Ludzinska, Izabela; Czajkowski, Caroline; Qiao, Yi; Kreutzer, Donald L

    2018-01-01

    Overcoming sensor-induced tissue reactions is an essential element of achieving successful continuous glucose monitoring (CGM) in the management of diabetes, particularly when used in closed loop technology. Recently, we demonstrated that basement membrane (BM)-based glucose sensor coatings significantly reduced tissue reactions at sites of device implantation. However, the biocompatible BM-based biohydrogel sensor coating rapidly degraded over a less than a 3-week period, which effectively eliminated the protective sensor coating. In an effort to increase the stability and effectiveness of the BM coating, we evaluated the impact of crosslinking BM utilizing glutaraldehyde as a crosslinking agent, designated as X-Cultrex. Sensor performance (nonrecalibrated) was evaluated for the impact of these X-Cultrex coatings in vitro and in vivo. Sensor performance was assessed over a 28-day time period in a murine CGM model and expressed as mean absolute relative difference (MARD) values. Tissue reactivity of Cultrex-coated, X-Cultrex-coated, and uncoated glucose sensors was evaluated over a 28-day time period in vivo using standard histological techniques. These studies demonstrated that X-Cultrex-based sensor coatings had no effect on glucose sensor function in vitro. In vivo, glucose sensor performance was significantly enhanced following X-Cultrex coating throughout the 28-day study. Histological evaluations of X-Cultrex-treated sensors demonstrated significantly less tissue reactivity when compared to uncoated sensors. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 7-16, 2018. © 2017 Wiley Periodicals, Inc.

  19. AMACO is a novel component of the basement membrane associated Fraser complex

    Science.gov (United States)

    Richardson, Rebecca J.; Gebauer, Jan M.; Zhang, Jin-Li; Kobbe, Birgit; Keene, Douglas R.; Karlsen, Kristina Røkenes; Richetti, Stefânia; Wohl, Alexander P.; Sengle, Gerhard; Neiss, Wolfram F.; Paulsson, Mats; Hammerschmidt, Matthias; Wagener, Raimund

    2015-01-01

    Fraser syndrome (FS) is a phenotypically variable, autosomal recessive disorder characterized by cryptophthalmus, cutaneous syndactyly and other malformations resulting from mutations in FRAS1, FREM2 and GRIP1. Transient embryonic epidermal blistering causes the characteristic defects of the disorder. Fras1, Frem1 and Frem2 form the extracellular Fraser complex, which is believed to stabilize the basement membrane (BM). However, several cases of FS could not be attributed to mutations in FRAS1, FREM2 or GRIP1, while Fraser syndrome displays high clinical variability, suggesting there is an additional genetic, possibly modifying contribution to this disorder. AMACO, encoded by the VWA2 gene, has a very similar tissue distribution to the Fraser complex proteins in both mouse and zebrafish. Here, we show that AMACO deposition is lost in Fras1 deficient zebrafish and mice and that Fras1 and AMACO interact directly via their CSPG and P2 domains. Knockdown of vwa2, which alone causes no phenotype, enhances the phenotype of hypomorphic Fras1 mutant zebrafish. Together, our data suggest that AMACO represents a novel member of the Fraser complex. PMID:24232570

  20. Epithelial basement membrane injury and regeneration modulates corneal fibrosis after pseudomonas corneal ulcers in rabbits.

    Science.gov (United States)

    Marino, Gustavo K; Santhiago, Marcony R; Santhanam, Abirami; Lassance, Luciana; Thangavadivel, Shanmugapriya; Medeiros, Carla S; Bose, Karthikeyan; Tam, Kwai Ping; Wilson, Steven E

    2017-08-01

    The purpose of this study was to investigate whether myofibroblast-related fibrosis (scarring) after microbial keratitis was modulated by the epithelial basement membrane (EBM) injury and regeneration. Rabbits were infected with Pseudomonas aeruginosa after epithelial scrape injury and the resultant severe keratitis was treated with topical tobramycin. Corneas were analyzed from one to four months after keratitis with slit lamp photos, immunohistochemistry for alpha-smooth muscle actin (α-SMA) and monocyte lineage marker CD11b, and transmission electron microscopy. At one month after keratitis, corneas had no detectible EBM lamina lucida or lamina densa, and the central stroma was packed with myofibroblasts that in some eyes extended to the posterior corneal surface with damage to Descemet's membrane and the endothelium. At one month, a nest of stromal cells in the midst of the SMA + myofibroblasts in the stroma that were CD11b+ may be fibrocyte precursors to myofibroblasts. At two to four months after keratitis, the EBM fully-regenerated and myofibroblasts disappeared from the anterior 60-90% of the stroma of all corneas, except for one four-month post-keratitis cornea where anterior myofibroblasts were still present in one localized pocket in the cornea. The organization of the stromal extracellular matrix also became less disorganized from two to four months after keratitis but remained abnormal compared to controls at the last time point. Myofibroblasts persisted in the posterior 10%-20% of posterior stroma even at four months after keratitis in the central cornea where Descemet's membrane and the endothelium were damaged. This study suggests that the EBM has a critical role in modulating myofibroblast development and fibrosis after keratitis-similar to the role of EBM in fibrosis after photorefractive keratectomy. Damage to EBM likely allows epithelium-derived transforming growth factor beta (TGFβ) to penetrate the stroma and drive development and

  1. Distribution of two basement membrane proteoglycans through hair follicle development and the hair growth cycle in the rat

    DEFF Research Database (Denmark)

    Couchman, J R; King, J L; McCarthy, K J

    1990-01-01

    The distribution of two distinct populations of basement membrane proteoglycans has been monitored through hair growth development in the rat embryo and subsequent hair growth cycle. An antiserum against a small heparan sulfate proteoglycan uniformly stained the dermal-epidermal junction...... as they developed. Through the hair growth cycle, it was found that the heparan sulfate proteoglycan persisted around the follicles, while the chondroitin sulfate proteoglycan decreased in amount through catagen until it was undetectable at the base and dermal papilla of the telogen follicle. As anagen commenced...... of embryonic rats throughout the period of hair follicle formation. On the other hand, monoclonal antibodies recognizing a basement membrane-specific chondroitin sulfate proteoglycan only weakly stained 16-d embryo dermal-epidermal junction, but strong staining was associated with hair follicle buds...

  2. Human skin basement membrane-associated heparan sulphate proteoglycan: distinctive differences in ultrastructural localization as a function of developmental age

    DEFF Research Database (Denmark)

    Horiguchi, Y; Fine, J D; Couchman, J R

    1991-01-01

    at different developmental ages using two monoclonal antibodies to a well-characterized basement membrane-associated heparan sulphate proteoglycan. A series of foetal skin specimens (range, 54-142 gestational days) were examined using an immunoperoxidase immunoelectron microscopic technique. In specimens...... representing very early developmental ages, very diffuse immunoreaction products were detected. However, by approximately 76 gestational days, some accentuation of heparan sulphate proteoglycan was noted along the lamina densa, and by 142 gestational days, the distribution of heparan sulphate proteoglycan...... was identical to that observed in neonatal and adult human skin. These findings demonstrate that active remodelling of the dermo-epidermal junction occurs during at least the first two trimesters, and affects not only basement membrane-associated structures but also specific antigens....

  3. Aluminum-containing dense deposits of the glomerular basement membrane: identification by energy dispersive X-ray analysis

    International Nuclear Information System (INIS)

    Smith, D.M. Jr.; Pitcock, J.A.; Murphy, W.M.

    1982-01-01

    Heavy metals, including gold, mercury, lead, bismuth, and cadmium, have the potential to cause renal disease. With the development of X-ray microanalysis, these heavy metals can now be identified in tissue deposits. This report describes a case of renal failure, probably related to dysproteinemia, in which granular, electron-opaque dense deposits were present in the glomerular basement membranes. Energy dispersive X-ray analysis demonstrated that these dense deposits contained aluminum. An analysis of this patient's history in relation to the current knowledge of aluminum metabolism suggests that the aluminum deposition occurred secondary to previous glomerular injury. This case emphasizes the need to utilize heavy metal identification technology whenever granular, electron-opaque dense deposits are identified and represents, to our knowledge, the first study to document aluminum deposits within the glomerular basement membrane of humans

  4. CCN2/connective tissue growth factor is essential for pericyte adhesion and endothelial basement membrane formation during angiogenesis.

    Directory of Open Access Journals (Sweden)

    Faith Hall-Glenn

    Full Text Available CCN2/Connective Tissue Growth Factor (CTGF is a matricellular protein that regulates cell adhesion, migration, and survival. CCN2 is best known for its ability to promote fibrosis by mediating the ability of transforming growth factor β (TGFβ to induce excess extracellular matrix production. In addition to its role in pathological processes, CCN2 is required for chondrogenesis. CCN2 is also highly expressed during development in endothelial cells, suggesting a role in angiogenesis. The potential role of CCN2 in angiogenesis is unclear, however, as both pro- and anti-angiogenic effects have been reported. Here, through analysis of Ccn2-deficient mice, we show that CCN2 is required for stable association and retention of pericytes by endothelial cells. PDGF signaling and the establishment of the endothelial basement membrane are required for pericytes recruitment and retention. CCN2 induced PDGF-B expression in endothelial cells, and potentiated PDGF-B-mediated Akt signaling in mural (vascular smooth muscle/pericyte cells. In addition, CCN2 induced the production of endothelial basement membrane components in vitro, and was required for their expression in vivo. Overall, these results highlight CCN2 as an essential mediator of vascular remodeling by regulating endothelial-pericyte interactions. Although most studies of CCN2 function have focused on effects of CCN2 overexpression on the interstitial extracellular matrix, the results presented here show that CCN2 is required for the normal production of vascular basement membranes.

  5. [Research on ultrasonic permeability of low intensity pulsed ultrasound through PTFE membrane and Bio-Gide collagen membrane].

    Science.gov (United States)

    Chai, Zhaowu; Zhao, Chunliang; Song, Jinlin; Deng, Feng; Yang, Ji; Gao, Xiang; Liu, Minyi

    2013-12-01

    The aim of the present study was to detect the transmission rate of ultrasonic low intensity pulsed ultrasound (LIPUS) through polytetrafluoroethylene (PTFE) membrane (Thickness: 0.01 mm) and Bio-Gide collagen membrane, and to provide the basis for the barrier membrane selection on the study of LIPUS combined with guided tissue regeneration (GTR). The ultrasonic (LIPUS, frequency 1.5 MHz, pulse width 200 micros, repetition rate 1.0 kHz) transmission coefficient of the two kinds of barrier membrane were detected respectively through setting ten groups from 10 to 100mW/cm2 every other 10 mW/cm2. We found in the study that the ultrasonic transmission coefficient through 0.01 mm PTFE membrane was 78.1% to 92.%, and the ultrasonic transmission coefficient through Bio-Gide collagen membrane was 43.9% to 55.8%. The ultrasonic transmission coefficient through PTFE membrane was obviously higher than that through Bio-Gide collagen membrane. The transmission coefficient of the same barrier membrane of the ultrasonic ion was statistically different under different powers (P PTFE membrane and Bio-Gide collagen membrane were relatively high. We should select barrier membranes based on different experimental needs, and exercise ultrasonic transmission coefficient experiments to ensure effective power.

  6. Basement membrane heterogeneity during chick development as shown by tomato (Lycopersicon esculentum) lectin binding.

    Science.gov (United States)

    Ojeda, J L; Icardo, J M

    2006-03-01

    Basement membranes (BMs) constitute a distinct compartment of the extracellular matrix (ECM). All BMs show a similar structural appearance but differ in molecular composition. These variations have critical functional implications. The aim of this study is to establish the pattern of the tomato lectin (Lycopersicon esculentum agglutinin--LEA) binding sites in the BMs of the developing chick embryo (stages 4-21, Hamburger and Hamilton, 1951) in order to achieve a better understanding of the molecular heterogeneity of BMs. The study was performed with transmission electron microscopy (TEM) histochemistry, and confocal laser microscopy. TEM showed that LEA bound to the lamina densa and to the lamina fibroreticularis of the BMs. Through the period studied, most of the LEA binding appeared in the ectodermal BM and its derivatives. In the limb bud, LEA binding to the ectoderm BM was more intense in the ventral half than in the dorsal half. Furthermore, LEA allowed the early (HH16) detection of the transverse fibrillar tracts. In the lens and in the inner ear primordium, the BMs were LEA positive through the placode and cup stages. The binding was progressively reduced through the vesicle stage. The BMs of the olfactory primordium, and of the Rathke's pouch were positive. In contrast, the BMs of the developing central nervous system were negative. The BMs of both the paraxial and the lateral plates of the mesoderm were negative, whereas the notochord and the BM of the Wolffian duct were positive. The endodermal BM and its derivatives were negative. The ECM located between the fusing endocardial tubes, and the BM of the fusion zone of the paired aortae, were positive. This suggested an active role of the LEA-positive glycoproteins in the fusion of endothelia. Our results show the heterogeneity of the chick embryo BMs during development. In addition, LEA constitutes an excellent marker for the primordial germ cells.

  7. A “Mini-Epidemic” of anti-glomerular basement membrane disease: Clinical and epidemiological study

    Directory of Open Access Journals (Sweden)

    Umesh Lingaraj

    2017-01-01

    Full Text Available Acute glomerulonephritis due to anti-glomerular basement membrane (anti-GBM antibody disease is rare, estimated to occur in fewer than one case per million population and accounts for less than 20% of rapidly progressive glomerulonephritis. The prevalence among patients evaluated for potential glomerular disease is lower. It accounts for fewer than 3% of all kidney biopsies done with crescentic glomerulonephritis. Cases of anti-GBM disease occurring in a cluster have rarely been reported. All biopsy proven anti-GBM disease cases were collected from January 2015 to March 2015 at our Institute. All cases were analyzed for demographic and clinical profile, pathological findings, treatment received and for any common environmental antigenic source. A total of 11 new biopsy proven anti-GBM cases were seen within a span of three months. Age group varied from 17–80 years. Seven were males and four were females. All were dialysis dependent at presentation. Seven had active cellular crescents, and four had fibrocellular. Only one patient was a smoker and none had a history of exposure to any forms of hydrocarbons. The peak seen from January 2015 to March 2015 does not correlate with any of seasonal occurrence of infections in southern India. Although there was clustering of cases to southern territories of Karnataka state, no common etiological agents could be identified. No patient had any previous urological surgeries. All patients received methylprednisolone with plasmapheresis 5–7 sessions and cyclophosphamide. All 11 patients were dialysis dependent at the end of three months. We conclude anti-GBM disease cannot be regarded as a rare cause of renal failure and lung hemorrhage. The occurrence of such epidemic within a short period suggests a possible unidentified environmental factor like infection or occupational agents as inciting agents. Identification of such inciting agents could help us in instituting appropriate preventing measures.

  8. Ultrastructural and Temporal Changes of the Microvascular Basement Membrane and Astrocyte Interface Following Focal Cerebral Ischemia

    Science.gov (United States)

    Kwon, Il; Kim, Eun Hee; del Zoppo, Gregory J.; Heo, Ji Hoe

    2009-01-01

    Microvascular integrity is lost during cerebral ischemia. Detachment of the microvascular basement membrane (BM) from the astrocyte, as well as degradation of the BM, is responsible for the loss of microvascular integrity. However, their ultrastructural and temporal changes during cerebral ischemia are not well known. Male Sprague-Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAO) for 1, 4, 8, 12, 16, 20, and 48 hr. By using transmission electron microscopy, the proportion of intact BM–astrocyte contacts and electron densities of the BM were measured from five randomly selected microvessels in the ischemic basal ganglia. Their temporal changes and associations with activities of the matrix metalloproteinases (MMPs) were investigated. The intact portion of the BM–astrocyte contacts was decreased significantly within 4 hr and was rarely observed at 48 hr after MCAO. Decreases in the electron density and degradation of the BM were significant 12 hr after MCAO. The intact BM–astrocyte contacts and the mean BM density showed a significant positive correlation (r = 0.784, P < 0.001). MMP-9 activity was correlated negatively with the intact BM–astrocyte contacts (r = −0.711, P < 0.001) and with the BM density (r = −0.538, P 5 0.0016). The increase in MMP-9 coincided temporally with the loss of the BM–astrocyte contacts and a decrease in the BM density. Ultrastructural alterations occurring in the microvascular BM and its contacts with astrocyte endfeet were temporally associated in cerebral ischemia. Time courses of their alterations should be considered in the treatment targeted to the microvascular BM and its contact with astrocytes. PMID:18831008

  9. Long-term outcome of anti-glomerular basement membrane antibody disease treated with immunoadsorption.

    Directory of Open Access Journals (Sweden)

    Peter Biesenbach

    Full Text Available Anti-glomerular basement membrane (GBM antibody disease may lead to acute crescentic glomerulonephritis with poor renal prognosis. Current therapy favours plasma exchange (PE for removal of pathogenic antibodies. Immunoadsorption (IAS is superior to PE regarding efficiency of antibody-removal and safety. Apart from anecdotal data, there is no systemic analysis of the long-term effects of IAS on anti-GBM-disease and antibody kinetics.To examine the long-term effect of high-frequency IAS combined with standard immunosuppression on patient and renal survival in patients with anti-GBM-disease and to quantify antibody removal and kinetics through IAS.Retrospective review of patients treated with IAS for anti-GBM-antibody disease confirmed by biopsy and/or anti-GBM-antibodies.University Hospital of Vienna, Austria.10 patients with anti-GBM-disease treated with IAS.Patient and renal survival, renal histology, anti-GBM-antibodies.Anti-GBM-antibodies were reduced by the first 9 IAS treatments (mean number of 23 to negative levels in all patients. Renal survival was 40% at diagnosis, 70% after the end of IAS, 63% after one year and 50% at the end of observation (mean 84 months, range 9 to 186. Dialysis dependency was successfully reversed in three of six patients. Patient survival was 90% at the end of observation.IAS efficiently eliminates anti-GBM-antibodies suggesting non-inferiority to PE with regard to renal and patient survival. Hence IAS should be considered as a valuable treatment option for anti-GBM-disease, especially in patients presenting with a high percentage of crescents and dialysis dependency due to an unusual high proportion of responders.

  10. Chitosan-Coated Collagen Membranes Promote Chondrocyte Adhesion, Growth, and Interleukin-6 Secretion

    Directory of Open Access Journals (Sweden)

    Nabila Mighri

    2015-11-01

    Full Text Available Designing scaffolds made from natural polymers may be highly attractive for tissue engineering strategies. We sought to produce and characterize chitosan-coated collagen membranes and to assess their efficacy in promoting chondrocyte adhesion, growth, and cytokine secretion. Porous collagen membranes were placed in chitosan solutions then crosslinked with glutaraldehyde vapor. Fourier transform infrared (FTIR analyses showed elevated absorption at 1655 cm-1 of the carbon–nitrogen (N=C bonds formed by the reaction between the (NH2 of the chitosan and the (C=O of the glutaraldehyde. A significant peak in the amide II region revealed a significant deacetylation of the chitosan. Scanning electron microscopy (SEM images of the chitosan-coated membranes exhibited surface variations, with pore size ranging from 20 to 50 µm. X-ray photoelectron spectroscopy (XPS revealed a decreased C–C groups and an increased C–N/C–O groups due to the reaction between the carbon from the collagen and the NH2 from the chitosan. Increased rigidity of these membranes was also observed when comparing the chitosan-coated and uncoated membranes at dried conditions. However, under wet conditions, the chitosan coated collagen membranes showed lower rigidity as compared to dried conditions. Of great interest, the glutaraldehyde-crosslinked chitosan-coated collagen membranes promoted chondrocyte adhesion, growth, and interleukin (IL-6 secretion. Overall results confirm the feasibility of using designed chitosan-coated collagen membranes in future applications, such as cartilage repair.

  11. The collagen receptor uPARAP/Endo180 in tissue degradation and cancer (Review)

    DEFF Research Database (Denmark)

    Carlsen Melander, Eva Maria; Jürgensen, Henrik J; Madsen, Daniel H

    2015-01-01

    The collagen receptor uPARAP/Endo180, the product of the MRC2 gene, is a central component in the collagen turnover process governed by various mesenchymal cells. Through the endocytosis of collagen or large collagen fragments, this recycling receptor serves to direct basement membrane collagen a...... by an in-depth survey of the available knowledge of the expression and role of this receptor in various types of cancer and other degenerative diseases....

  12. Degradation pattern of a porcine collagen membrane in an in vivo model of guided bone regeneration.

    Science.gov (United States)

    Calciolari, E; Ravanetti, F; Strange, A; Mardas, N; Bozec, L; Cacchioli, A; Kostomitsopoulos, N; Donos, N

    2018-02-15

    Although collagen membranes have been clinically applied for guided tissue/bone regeneration for more than 30 years, their in vivo degradation pattern has never been fully clarified. A better understanding of the different stages of in vivo degradation of collagen membranes is extremely important, considering that the biology of bone regeneration requires the presence of a stable and cell/tissue-occlusive barrier during the healing stages in order to ensure a predictable result. Therefore, the aim of this study was to investigate the degradation pattern of a porcine non-cross-linked collagen membrane in an in vivo model of guided bone regeneration (GBR). Decalcified and paraffin-embedded specimens from calvarial defects of 18, 10-month-old Wistar rats were used. The defects were treated with a double layer of collagen membrane and a deproteinized bovine bone mineral particulate graft. At 7, 14 and 30 days of healing, qualitative evaluation with scanning electron microscopy and atomic force microscopy, and histomorphometric measurements were performed. Markers of collagenase activity and bone formation were investigated using an immunofluorescence technique. A significant reduction of membrane thickness was observed from 7 to 30 days of healing, which was associated with progressive loss of collagen alignment, increased collagen remodeling and progressive invasion of woven bone inside the membranes. A limited inflammatory infiltrate was observed at all time points of healing. The collagen membrane investigated was biocompatible and able to promote bone regeneration. However, pronounced signs of degradation were observed starting from day 30. Since successful regeneration is obtained only when cell occlusion and space maintenance exist for the healing time needed by the bone progenitor cells to repopulate the defect, the suitability of collagen membranes in cases where long-lasting barriers are needed needs to be further reviewed. © 2018 John Wiley & Sons A

  13. In Vitro and In Vivo Study of a Novel Porcine Collagen Membrane for Guided Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Eisner Salamanca

    2016-11-01

    Full Text Available For years, in order to improve bone regeneration and prevent the need of a second stage surgery to remove non-resorbable membranes, biological absorbable membranes have gradually been developed and applied in guided tissue regeneration (GTR. The present study’s main objective was to achieve space maintenance and bone regeneration using a new freeze-dried developed porcine collagen membrane, and compare it with an already commercial collagen membrane, when both were used with a bovine xenograft in prepared alveolar ridge bone defects. Prior to surgery, the membrane’s vitality analysis showed statistically significant higher cell proliferation in the test membrane over the commercial one. In six beagle dogs, commercial bone xenograft was packed in lateral ridge bone defects prepared in the left and right side and then covered with test porcine collagen membrane or commercial collagen membrane. Alveolar height changes were measured. Histomorphometric results, in vitro and in vivo properties indicated that the new porcine collagen membrane is biocompatible, enhances bone xenograft osteoconduction, and reduces the alveolar ridge height reabsorption rate.

  14. Collagen mRNA levels changes during colorectal cancer carcinogenesis

    DEFF Research Database (Denmark)

    Skovbjerg, Hanne; Anthonsen, Dorit; Lothe, Inger M B

    2009-01-01

    BACKGROUND: Invasive growth of epithelial cancers is a complex multi-step process which involves dissolution of the basement membrane. Type IV collagen is a major component in most basement membranes. Type VII collagen is related to anchoring fibrils and is found primarily in the basement membrane...... zone of stratified epithelia. Immunohistochemical studies have previously reported changes in steady-state levels of different alpha(IV) chains in several epithelial cancer types. In the present study we aimed to quantitatively determine the mRNA levels of type IV collagen (alpha1/alpha 4/alpha 6......) and type VII collagen (alpha1) during colorectal cancer carcinogenesis. METHODS: Using quantitative RT-PCR, we have determined the mRNA levels for alpha1(IV), alpha 4(IV), alpha 6(IV), and alpha1(VII) in colorectal cancer tissue (n = 33), adenomas (n = 29) and in normal tissue from the same individuals...

  15. Evaluation of sericin/collagen membranes as prospective wound dressing biomaterial.

    Science.gov (United States)

    Akturk, Omer; Tezcaner, Aysen; Bilgili, Hasan; Deveci, M Salih; Gecit, M Rusen; Keskin, Dilek

    2011-09-01

    Sericin, a silk protein, has high potential for use in biomedical applications. In this study, wound dressing membranes of Sericin (S) and Collagen (C) were prepared by glutaraldehyde cross-linking at S/C; 2:1, 1:1, 1:2, and 0:1 weight ratios. They were stable in water for 4 weeks. However, increasing the proportion of sericin had decreasing effect on the membrane stability. Water swelling property of membranes was enhanced with sericin. The highest water swelling was obtained in 1:1 group (9.06 g/g), but increasing collagen or sericin content in the membranes had a diminishing effect. Highest water vapor transmission rate was obtained with 1:2 group (1013.80 g/m(2)/day). Oxygen permeability results showed that 1:2 (7.67 mg/L) and 2:1 (7.85 mg/L) S/C groups were better than the other groups. While sericin decreased the tensile strength and elongation of membranes, it increased modulus. Sericin also increased brittleness of membranes, but their UTS range (24.93-44.92 MPa) was still suitable for a wound dressing. Membranes were not penetrable to microorganisms. Cytotoxicity studies showed that fibroblasts and keratinocytes attached and gained their characteristic morphologies. They also proliferated on membranes significantly. After 1 week of subcutaneous implantation, a fibrous capsule formed around all membranes with an acute inflammation. Sericin containing membranes showed signs of degradation (at 2nd week), while collagen only membranes remained largely intact. Eventually, sericin containing membranes degraded in 3 weeks with moderate inflammatory response. Overall results suggest that sericin/collagen membranes would be favorable as wound dressing material when sericin ratio is less than or equal to the collagen component. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  16. De novo deposition of laminin-positive basement membrane in vitro by normal hepatocytes and during hepatocarcinogenesis

    DEFF Research Database (Denmark)

    Albrechtsen, R; Wewer, U M; Thorgeirsson, S S

    1988-01-01

    De novo formation of laminin-positive basement membranes was found to be a distinct morphologic feature of diethylnitrosamine/phenobarbital-induced hepatocellular carcinomas of the rat. The first appearance of extracellularly located laminin occurred in the preneoplastic liver lesions......, a location where no laminin was seen in normal rat liver. The amount of extractable laminin from hepatocellular carcinomas was significantly higher (approximately 100 ng per mg tissue) than that of normal liver tissue (less than 20 ng per mg). In vitro experiments demonstrated that normal and preneoplastic...

  17. Targeted Expression of Stromelysin-1 in Mammary Gland Provides Evidence for a Role of Proteinases in Branching Morphogenesis and the Requirement for an Intact Basement Membrane for Tissue-specific Gene Expression

    Energy Technology Data Exchange (ETDEWEB)

    Sympson, Carolyn J; Talhouk, Rabih S; Alexander, Caroline M; Chin, Jennie R; Cliff, Shirley M; Bissell, Mina J; Werb, Zena

    1994-05-01

    The extracellular matrix (ECM) is an important regulator of the differentiated phenotype of mammary epithelial cells in culture. Despite the fact that ECM-degrading enzymes have been implicated in morphogenesis and tissue remodeling, there is little evidence for a direct role for such regulation in vivo. We generated transgenic mice that express autoactivated isoforms of the matrix metalloproteinase stromelysin-1, under the control of the whey acidic protein gene promoter, to examine the effect of inappropriate expression of this enzyme. Stromelysin-1 is implicated as the primary player in the loss of basement membrane and loss of function in the mammary gland during involution. The transgene was expressed at low levels in mammary glands of virgin female mice, leading to an unexpected phenotype: The primary ducts had supernumerary branches and showed precocious development of alveoli that expressed beta-casein at levels similar to that of an early- to mid-pregnant gland. Lactating glands showed high levels of transgene expression, with accumulation at the basement membrane, and a decrease in laminin and collagen IV, resulting in a loss of basement membrane integrity; this was accompanied by a dramatic alteration of alveolar morphology, with decreased size and shrunken lumina containing little beta-casein. During pregnancy, expression of endogenous whey acidic protein and beta-casein was reduced in transgenic glands, confirming the observed dependence of milk protein transcription of ECM in mammary epithelial cells in culture. These data provide direct evidence that stromelysin-1 activity can be morphogenic for mammary epithelial cells, inducing hyperproliferation and differentiation in virgin animals, and that its lytic activity can, indeed, disrupt membrane integrity and reduce mammary-specific function. We conclude that the balance of ECM-degrading enzymes with their inhibitors, and the associated regulation of ECM structure, is crucial for tissue-specific gene

  18. Improving the mechanical properties of collagen-based membranes using silk fibroin for corneal tissue engineering.

    Science.gov (United States)

    Long, Kai; Liu, Yang; Li, Weichang; Wang, Lin; Liu, Sa; Wang, Yingjun; Wang, Zhichong; Ren, Li

    2015-03-01

    Although collagen with outstanding biocompatibility has promising application in corneal tissue engineering, the mechanical properties of collagen-based scaffolds, especially suture retention strength, must be further improved to satisfy the requirements of clinical applications. This article describes a toughness reinforced collagen-based membrane using silk fibroin. The collagen-silk fibroin membranes based on collagen [silk fibroin (w/w) ratios of 100:5, 100:10, and 100:20] were prepared by using silk fibroin and cross-linking by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. These membranes were analyzed by scanning electron microscopy and their optical property, and NaCl and tryptophan diffusivity had been tested. The water content was found to be dependent on the content of silk fibroin, and CS10 membrane (loading 10 wt % of silk fibroin) performed the optimal mechanical properties. Also the suture experiments have proved CS10 has high suture retention strength, which can be sutured in rabbit eyes integrally. Moreover, the composite membrane proved good biocompatibility for the proliferation of human corneal epithelial cells in vitro. Lamellar keratoplasty shows that CS10 membrane promoted complete epithelialization in 35 ± 5 days, and their transparency is restored quickly in the first month. Corneal rejection reaction, neovascularization, and keratoconus are not observed. The composite films show potential for use in the field of corneal tissue engineering. © 2014 Wiley Periodicals, Inc.

  19. GLIAL CELLS AND COLLAGENS IN EPIRETINAL MEMBRANES ASSOCIATED WITH IDIOPATHIC MACULAR HOLES

    NARCIS (Netherlands)

    Bu, Shao-Chong; Kuijer, Roelof; van der Worp, Roelofje J.; Huiskamp, Eveline A.; De Lavalette, Victor W. Renardel; Li, Xiao-Rong; Hooymans, Johanna M. M.; Los, Leonoor I.

    Purpose: To investigate the identity of collagens and cellular components in the epiretinal membrane (ERM) associated with full-thickness idiopathic macular hole and their clinical relevance. Methods: Pars plana vitrectomy with the peeling of internal limiting membrane and ERM was performed by 2

  20. In Vivo Immune Responses of Cross-Linked Electrospun Tilapia Collagen Membrane.

    Science.gov (United States)

    Hassanbhai, Ammar Mansoor; Lau, Chau Sang; Wen, Feng; Jayaraman, Praveena; Goh, Bee Tin; Yu, Na; Teoh, Swee-Hin

    2017-10-01

    Collagen has been used extensively in tissue engineering applications. However, the source of collagen has been primarily bovine and porcine. In view of the potential risk of zoonotic diseases and religious constraints associated with bovine and porcine collagen, fish collagen was examined as an alternative. The aim of this study is to use tilapia fish collagen to develop a cross-linked electrospun membrane to be used as a barrier membrane in guided bone regeneration. As there is limited data available on the cytotoxicity and immunogenicity of cross-linked tilapia collagen, in vitro and in vivo tests were performed to evaluate this in comparison to the commercially available Bio-Gide ® membrane. In this study, collagen was extracted and purified from tilapia skin and electrospun into a nanofibrous membrane. The resultant membrane was cross-linked to obtain a cross-linked electrospun tilapia collagen (CETC) membrane, which was characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), degradation studies, cytotoxicity studies, and cell proliferation studies. The membranes were also implanted subcutaneously in rats and the host immune responses were examined. The DSC data showed that cross-linking increased the denaturation temperature of tilapia collagen to 58.3°C ± 1.4°C. The in vitro tests showed that CETC exhibited no cytotoxicity toward murine fibroblast L929 cells, and culture of murine preosteoblast MC3T3-E1 cells demonstrated better proliferation on CETC as compared to Bio-Gide. When implanted in rats, CETC caused a higher production of interleukin IL-6 at early time points as compared to Bio-Gide, but there was no long-term inflammatory responses after the acute inflammation phase. This finding was supported with histology data, which clearly illustrated that CETC has a decreased inflammatory response comparable to the benchmark control group. In all, this study demonstrated the viability for the use of CETC as a

  1. Collagen barrier membranes adsorb growth factors liberated from autogenous bone chips.

    Science.gov (United States)

    Caballé-Serrano, Jordi; Sawada, Kosaku; Miron, Richard J; Bosshardt, Dieter D; Buser, Daniel; Gruber, Reinhard

    2017-02-01

    Collagen membranes serve as barriers to separate bone grafts from soft tissues. Bone grafts harvested with a bone scraper release growth factors activating transforming growth factor-β (TGF-β) signaling in mesenchymal cells. The aim of the present pilot study was to determine whether collagen membranes adsorb molecules from bone-conditioned medium (BCM) with the capacity to provoke the expression of TGF-β target genes in vitro. Collagen membranes were soaked in aqueous extracts from fresh and demineralized bone chips placed in cell culture medium. Recombinant human TGF-β1 served as control. Gingival fibroblasts were seeded onto the washed collagen membranes and evaluated for the expression of adrenomedullin, pentraxin 3, interleukin 11, and proteoglycan 4. Cell viability and morphology with phalloidin staining were also determined. Incubation of collagen membranes with BCM for at least one minute caused fibroblasts to decrease the expression of adrenomedullin and pentraxin 3, and to increase the expression of interleukin 11 and proteoglycan 4. Four different membrane treatments - incubated with recombinant TGF-β1, pre-wetted with saline solution, exposed to UV light, and dry out and stored one week at room temperature - also provoked significant changes in gene expression. Likewise, conditioned medium from demineralized bone chips caused gene expression changes. BCM did not alter the viability or morphology of gingival fibroblasts. These findings demonstrate that collagen membranes rapidly adsorb the TGF-β activity released from bone chips, a molecular process that might contribute to guided bone regeneration. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Chondrocyte-seeded type I/III collagen membrane for autologous chondrocyte transplantation

    DEFF Research Database (Denmark)

    Niemeyer, Philipp; Lenz, Philipp; Kreuz, Peter C

    2010-01-01

    PURPOSE: We report the 2-year clinical results and identify prognostic factors in patients treated with autologous chondrocyte transplantation by use of a collagen membrane to seed the chondrocytes (ACT-CS). METHODS: This is a prospective study of 59 patients who were treated with ACT-CS and foll......PURPOSE: We report the 2-year clinical results and identify prognostic factors in patients treated with autologous chondrocyte transplantation by use of a collagen membrane to seed the chondrocytes (ACT-CS). METHODS: This is a prospective study of 59 patients who were treated with ACT...

  3. A role for PDGF-C/PDGFRα signaling in the formation of the meningeal basement membranes surrounding the cerebral cortex

    Directory of Open Access Journals (Sweden)

    Johanna Andrae

    2016-04-01

    Full Text Available Platelet-derived growth factor-C (PDGF-C is one of three known ligands for the tyrosine kinase receptor PDGFRα. Analysis of Pdgfc null mice has demonstrated roles for PDGF-C in palate closure and the formation of cerebral ventricles, but redundancy with other PDGFRα ligands might obscure additional functions. In search of further developmental roles for PDGF-C, we generated mice that were double mutants for Pdgfc−/− and PdgfraGFP/+. These mice display a range of severe phenotypes including spina bifida, lung emphysema, abnormal meninges and neuronal over-migration in the cerebral cortex. We focused our analysis on the central nervous system (CNS, where PDGF-C was identified as a critical factor for the formation of meninges and assembly of the glia limitans basement membrane. We also present expression data on Pdgfa, Pdgfc and Pdgfra in the cerebral cortex and microarray data on cerebral meninges.

  4. Sequential development of pulmonary hemorrhage with MPO-ANCA complicating anti-glomerular basement membrane antibody-mediated glomerulonephritis.

    Science.gov (United States)

    Peces, R; Rodríguez, M; Pobes, A; Seco, M

    2000-05-01

    We report a case of rapidly progressive glomerulonephritis caused by anti-glomerular basement membrane (anti-GBM) antibodies that progressed to end-stage renal disease in a 67-year-old woman with diabetes. Intensive combined immunosuppressive therapy with methylprednisolone bolus, oral prednisone, and cyclophosphamide led to negativity of anti-GBM antibodies but was not able to restore renal function. After 28 months of hemodialysis, the patient suddenly presented with pulmonary hemorrhage. In this setting, high levels of myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA) and negative anti-GBM antibodies were found. Therapy with oral prednisone and cyclophosphamide led to resolution of pulmonary hemorrhage and negativity of MPO-ANCA.

  5. Defective muscle basement membrane and lack of M-laminin in the dystrophic dy/dy mouse

    DEFF Research Database (Denmark)

    Xu, H; Christmas, P; Wu, X R

    1994-01-01

    -linked Duchenne and Becker muscular dystrophies. We have examined M-laminin expression in mice with autosomal recessive muscular dystrophy caused by the mutation dy. The heavy chain of M-laminin was undetectable in skeletal muscle, heart muscle, and peripheral nerve by immunofluorescence and immunoblotting......M-laminin is a major member of the laminin family of basement membrane proteins. It is prominently expressed in striated muscle and peripheral nerve. M-laminin is deficient in patients with the autosomal recessive Fukuyama congenital muscular dystrophy but is normal in patients with the sex...... tissue from dy/dy mice, suggesting that M-laminin heavy-chain mRNA may be produced at very low levels or is unstable. Information about the chromosomal localization of the M heavy-chain in human and mouse suggests that a mutation in the M-chain gene causes the muscular dystrophy in dy/dy mice. The dy...

  6. Histones have high affinity for the glomerular basement membrane. Relevance for immune complex formation in lupus nephritis

    International Nuclear Information System (INIS)

    Schmiedeke, T.M.; Stoeckl, F.W.W.; Weber, R.; Sugisaki, Y.; Batsford, S.R.; Vogt, A.

    1989-01-01

    An effort has been made to integrate insights on charge-based interactions in immune complex glomerulonephritis with nuclear antigen involvement in lupus nephritis. Attention was focussed on the histones, a group of highly cationic nuclear constituents, which could be expected to bind to fixed anionic sites present in the glomerular basement membrane (GBM). We demonstrated that all histone subfractions, prepared according to Johns, have a high affinity for GBM and the basement membrane of peritubular capillaries. Tissue uptake of 125 I-labeled histones was measured by injecting 200 micrograms of each fraction into the left kidney via the aorta and measuring organ uptake after 15 min. In glomeruli isolated from the left kidneys, the following quantities of histones were found: f1, 13 micrograms; f2a (f2al + f2a2), 17 micrograms; f2b, 17 micrograms; and f3, 32 micrograms. Kinetic studies of glomerular binding showed that f1 disappeared much more rapidly than f2a. The high affinity of histones (pI between 10.5 and 11.0; mol wt 10,000-22,000) for the GBM correlates well with their ability to form aggregates (mol wt greater than 100,000) for comparison lysozyme (pI 11, mol wt 14,000), which does not aggregate spontaneously bound poorly (0.4 micrograms in isolated glomeruli). The quantity of histones and lysozyme found in the isolated glomeruli paralleled their in vitro affinity for a Heparin-Sepharose column (gradient elution studies). This gel matrix contains the sulfated, highly anionic polysaccharide heparin, which is similar to the negatively charged heparan sulfate present in the GBM. Lysozyme eluted with 0.15 M NaCl, f1 with 1 M NaCl, and f2a, f2b, and f3 could not be fully desorbed even with 2 M NaCl; 6 M guanidine-HCl was necessary

  7. Histones have high affinity for the glomerular basement membrane. Relevance for immune complex formation in lupus nephritis

    Energy Technology Data Exchange (ETDEWEB)

    Schmiedeke, T.M.; Stoeckl, F.W.W.; Weber, R.; Sugisaki, Y.; Batsford, S.R.; Vogt, A.

    1989-06-01

    An effort has been made to integrate insights on charge-based interactions in immune complex glomerulonephritis with nuclear antigen involvement in lupus nephritis. Attention was focussed on the histones, a group of highly cationic nuclear constituents, which could be expected to bind to fixed anionic sites present in the glomerular basement membrane (GBM). We demonstrated that all histone subfractions, prepared according to Johns, have a high affinity for GBM and the basement membrane of peritubular capillaries. Tissue uptake of /sup 125/I-labeled histones was measured by injecting 200 micrograms of each fraction into the left kidney via the aorta and measuring organ uptake after 15 min. In glomeruli isolated from the left kidneys, the following quantities of histones were found: f1, 13 micrograms; f2a (f2al + f2a2), 17 micrograms; f2b, 17 micrograms; and f3, 32 micrograms. Kinetic studies of glomerular binding showed that f1 disappeared much more rapidly than f2a. The high affinity of histones (pI between 10.5 and 11.0; mol wt 10,000-22,000) for the GBM correlates well with their ability to form aggregates (mol wt greater than 100,000) for comparison lysozyme (pI 11, mol wt 14,000), which does not aggregate spontaneously bound poorly (0.4 micrograms in isolated glomeruli). The quantity of histones and lysozyme found in the isolated glomeruli paralleled their in vitro affinity for a Heparin-Sepharose column (gradient elution studies). This gel matrix contains the sulfated, highly anionic polysaccharide heparin, which is similar to the negatively charged heparan sulfate present in the GBM. Lysozyme eluted with 0.15 M NaCl, f1 with 1 M NaCl, and f2a, f2b, and f3 could not be fully desorbed even with 2 M NaCl; 6 M guanidine-HCl was necessary.

  8. Immunohistochemical localization of chondroitin sulfate, chondroitin sulfate proteoglycan, heparan sulfate proteoglycan, entactin, and laminin in basement membranes of postnatal developing and adult rat lungs

    DEFF Research Database (Denmark)

    Sannes, P L; Burch, K K; Khosla, J

    1993-01-01

    Histologic preparations of lungs from 1-, 5-, 10-, 18-, and 25-day-old postnatal and adult rats were examined immunohistochemically with antibodies specific against chondroitin sulfate (CS), basement membrane chondroitin sulfate proteoglycan (BM-CSPG), heparan sulfate proteoglycan (HSPG), entacti...

  9. 19-DEJ-1, a hemidesmosome-anchoring filament complex-associated monoclonal antibody. Definition of a new skin basement membrane antigenic defect in junctional and dystrophic epidermolysis bullosa

    DEFF Research Database (Denmark)

    Fine, J D; Horiguchi, Y; Couchman, J R

    1989-01-01

    50% of patients with recessive dystrophic EB further suggests, for the first time, that an inherited defect in basement membrane is shared in patients with junctional and some recessive dystrophic EB. The difference in site of skin cleavage in the latter two disorders gives additional support...

  10. Graphene oxide enrichment of collagen membranes improves DPSCs differentiation and controls inflammation occurrence.

    Science.gov (United States)

    Radunovic, Milena; De Colli, Marianna; De Marco, Patrizia; Di Nisio, Chiara; Fontana, Antonella; Piattelli, Adriano; Cataldi, Amelia; Zara, Susi

    2017-08-01

    Collagen membranes are used in oral surgery for bone defects treatment acting as a barrier that does not allow the invasion of soft tissue into the growing bone. To improve biocompatibility collagen membranes were coated with graphene oxide (GO), a graphene derivative. The aim of this study was to investigate the biocompatibility of GO coated collagen membranes on human dental pulp stem cells (DPSCs) focusing on biomaterial cytotoxicity, ability to promote DPSCs differentiation process and to control inflammation event induction. DPSCs were cultured on uncoated membranes and on both 2 and 10 μg mL -1 GO coated membranes up to 28 days. Alamar blue and LDH cytotocicity assay, PGE2 ELISA assay, real time RT-PCR for RUNX2, BMP2, SP7, TNFα and COX2 genes expression were performed. Proliferation is higher on GO coated membranes at days 14 and 28. LDH assay evidences no cytotoxicity. BMP2 and RUNX2 expression is higher on coated membranes, BMP2 at early and RUNX2 and SP7 at late experimental times. PGE2 levels are lower on GO coated membranes at days 14 and 28, both TNFα and COX2 expression is significantly decreased when GO is applied. GO coated membranes are not toxic for DPSCs, induce a faster DPSCs differentiation into odontoblasts/osteoblasts and may represent good alternative to conventional membranes thus ensuring more efficient bone formation and improving the clinical performance. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2312-2320, 2017. © 2017 Wiley Periodicals, Inc.

  11. A bioartificial environment for kidney epithelial cells based on a supramolecular polymer basement membrane mimic and an organotypical culture system.

    Science.gov (United States)

    Mollet, Björne B; Bogaerts, Iven L J; van Almen, Geert C; Dankers, Patricia Y W

    2017-06-01

    Renal applications in healthcare, such as renal replacement therapies and nephrotoxicity tests, could potentially benefit from bioartificial kidney membranes with fully differentiated and functional human tubular epithelial cells. A replacement of the natural environment of these cells is required to maintain and study cell functionality cell differentiation in vitro. Our approach was based on synthetic supramolecular biomaterials to mimic the natural basement membrane (BM) on which these cells grow and a bioreactor to provide the desired organotypical culture parameters. The BM mimics were constructed from ureidopyrimidinone (UPy)-functionalized polymer and bioactive peptides by electrospinning. The resultant membranes were shown to have a hierarchical fibrous BM-like structure consisting of self-assembled nanofibres within the electrospun microfibres. Human kidney-2 (HK-2) epithelial cells were cultured on the BM mimics under organotypical conditions in a custom-built bioreactor. The bioreactor facilitated in situ monitoring and functionality testing of the cultures. Cell viability and the integrity of the epithelial cell barrier were demonstrated inside the bioreactor by microscopy and transmembrane leakage of fluorescently labelled inulin, respectively. Furthermore, HK-2 cells maintained a polarized cell layer and showed modulation of both gene expression of membrane transporter proteins and metabolic activity of brush border enzymes when subjected to a continuous flow of culture medium inside the new bioreactor for 21 days. These results demonstrated that both the culture and study of renal epithelial cells was facilitated by the bioartificial in vitro environment that is formed by synthetic supramolecular BM mimics in our custom-built bioreactor. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  12. Gene expression profile of collagen types, osteopontin in the tympanic membrane of patients with tympanosclerosis.

    Science.gov (United States)

    Sakowicz-Burkiewicz, Monika; Kuczkowski, Jerzy; Przybyła, Tomasz; Grdeń, Marzena; Starzyńska, Anna; Pawełczyk, Tadeusz

    2017-09-01

    Tympanosclerosis is a pathological process involving the middle ear. The hallmark of this disease is the formation of calcium deposits. In the submucosal layer, as well as in the right layer of the tympanic membrane, the calcium deposits result in a significant increase in the activity of fibroblasts and deposition of collagen fibers. The aim of our study was to examine the expression level of genes encoding collagen type I, II, III and IV (COL1A1, COL2A1, COL3A1, COL4A1) and osteopontin (SPP1) in the tympanic membrane of patients with tympanosclerosis. The total RNA was isolated from middle ear tissues with tympanosclerosis, received from 25 patients and from 19 normal tympanic membranes. The gene expression level was determined by real-time RT-PCR. The gene expression levels were correlated with clinical Tos classification of tympanosclerosis. We observed that in the tympanic membrane of patients with tympanosclerosis, the expression of type I collagen is decreased, while the expression of type II and IV collagen and osteopontin is increased. Moreover, mRNA levels of the investigated genes strongly correlated with the clinical stages of tympanosclerosis. The strong correlations between the expression of type I, II, IV collagen and osteopontin and the clinical stage of tympanosclerosis indicate the involvement of these proteins in excessive fibrosis and pathological remodeling of the tympanic membrane. In the future, a treatment aiming to modulate these gene expressions and/or regulation of the degradation of their protein products could be used as a new medical approach for patients with tympanosclerosis.

  13. Ric-8a, a guanine nucleotide exchange factor for heterotrimeric G proteins, regulates bergmann glia-basement membrane adhesion during cerebellar foliation.

    Science.gov (United States)

    Ma, Shang; Kwon, Hyo Jun; Huang, Zhen

    2012-10-24

    The cerebellum consists of an intricate array of lobules that arises during the process of foliation. Foliation not only increases surface area, but may also facilitate organization of cerebellar neural circuitry. Defects in cerebellar foliation are associated with a number of diseases. Yet, little is known about how foliation, a process involving large-scale and simultaneous movement of several different cell types, is coordinated by cell-cell signaling at the molecular level. Here we show that Ric-8a, a guanine nucleotide exchange factor in the G-protein-coupled receptor pathway, is specifically required in Bergmann glia during cerebellar foliation. We find that ric-8a mutation in mice results in disorganized Bergmann glial scaffolding, defective granule cell migration, and disrupted Purkinje cell positioning. These abnormalities result from primary defects in Bergmann glia since mutations in granule cells do not show similar effects. They first arise during late embryogenesis, at the onset of foliation, when ric-8a mutant Bergmann glia fail to maintain adhesion to the basement membrane specifically at emerging fissures. This suggests that Ric-8a is essential for the enhanced Bergmann glia-basement membrane adhesion required for fissure formation. Indeed, we find that ric-8a-deficient cerebellar glia show decreased affinity for basement membrane components. We also find that weakening Bergmann glia-basement membrane interaction by β1 integrin deletion results in a similar phenotype. These results thus reveal a novel role of Ric-8a in modulating Bergmann glia-basement membrane adhesion during foliation, and provide new insights into the signaling pathways that coordinate cellular movement during cerebellar morphogenesis.

  14. Synthesis and localization of two sulphated glycoproteins associated with basement membranes and the extracellular matrix

    DEFF Research Database (Denmark)

    Hogan, B L; Taylor, A; Kurkinen, M

    1982-01-01

    interactions and are not precursors or products of each other. They contain asparagine-linked oligosaccharides, but these are not the exclusive sites of sulphate labeling. Antiserum raised against the Mr 150,000 sgp C of Reichert's membranes has been used in an immunohistochemical analysis of rat skin...

  15. Anti-glomerular basement membrane disease: Case series from a tertiary center in North India

    Directory of Open Access Journals (Sweden)

    D Prabhakar

    2017-01-01

    Full Text Available Anti-glomerular basement (anti-GBM disease is an uncommon disorder with a bimodal age of presentation. Patients presenting with dialysis-dependent renal failure have poor renal outcomes. There is limited data regarding the clinical presentation and outcomes of anti-GBM disease from India. We conducted this prospective study to analyze the clinical presentation and outcomes of anti-GBM disease at a large tertiary care hospital in North India over 1½ years. Subjects with a biopsy proven anti-GBM disease (light microscopic examination showing crescents and immunofluorescence examination showing linear deposition of IgG with or without positive anti-GBM antibodies in serum were included in the study and followed-up for at least 12 months. All the patients were treated with steroids, cyclophosphamide, and plasma exchange. A total of 17 patients (nine males were included. The mean age at presentation was 39.11 ± 16.58 (range 11–72 years. Twelve patients (70% presented with rapidly progressive glomerulonephritis (RPGN, 4 (23.5% presented with Goodpasture syndrome, while 1 (5.8% had nephritic syndrome, 7 (41% were hypertensive, and 14 (82.3% required dialysis at the time of presentation. Four patients (23.5% had associated anti-neutrophil cytoplasmic antibody positivity (anti-myeloperoxidase antibodies in all. Fourteen (87.5% patients had crescentic glomerulonephritis, while 5 (31.25% showed necrotizing (n = 4 or granulomatous (n = 1 in the vasculitis. Of 16 patients who received treatment, four (23.25% achieved complete remission. In this single-center study, the majority of anti-GBM disease patients presented with RPGN and had crescentic glomerulonephritis on biopsy with poor treatment outcome.

  16. A direct contact between astrocyte and vitreous body is possible in the rabbit eye due to discontinuities in the basement membrane of the retinal inner limiting membrane

    Directory of Open Access Journals (Sweden)

    A. Haddad

    2003-02-01

    Full Text Available Different from most mammalian species, the optic nerve of the rabbit eye is initially formed inside the retina where myelination of the axons of the ganglion cells starts and vascularization occurs. Astrocytes are confined to these regions. The aforementioned nerve fibers known as medullated nerve fibers form two bundles that may be identified with the naked eye. The blood vessels run on the inner surface of these nerve fiber bundles (epivascularization and, accordingly, the accompanying astrocytes lie mostly facing the vitreous body from which they are separated only by the inner limiting membrane of the retina. The arrangement of the astrocytes around blood vessels leads to the formation of structures known as glial tufts. Fragments (N = 3 or whole pieces (N = 3 of the medullated nerve fiber region of three-month-old male rabbits (Orictolagus cuniculus were fixed in glutaraldehyde followed by osmium tetroxide, and their thin sections were examined with a transmission electron microscope. Randomly located discontinuities (up to a few micrometers long of the basement membrane of the inner limiting membrane of the retina were observed in the glial tufts. As a consequence, a direct contact between the astrocyte plasma membrane and vitreous elements was demonstrated, making possible functional interactions such as macromolecular exchanges between this glial cell type and the components of the vitreous body.

  17. Different collagen types define two types of idiopathic epiretinal membranes

    OpenAIRE

    Kritzenberger , Michaela; Junglas , Benjamin; Framme , Carsten; Helbig , Horst; Gabel , Veit-Peter; Fuchshofer , Rudolf; Tamm , Ernst R; Hillenkamp , Jost

    2011-01-01

    Abstract Aims: To identify differences in extracellular matrix contents between idiopathic epiretinal membranes (IEM) of cellophane macular reflex (CMRM) or preretinal macular fibrosis (PMFM) type. Methods and results: IEM were analyzed by light and quantitative transmission electron microscopy, immunohistochemistry, and Western blotting. Substantial differences between CMRM and PMFM were observed regarding the nature of extracellular fibrils. In CMRM, the fibrils were thin with...

  18. In vivo imaging of basement membrane movement: ECM patterning shapes Hydra polyps.

    Science.gov (United States)

    Aufschnaiter, Roland; Zamir, Evan A; Little, Charles D; Özbek, Suat; Münder, Sandra; David, Charles N; Li, Li; Sarras, Michael P; Zhang, Xiaoming

    2011-12-01

    Growth and morphogenesis during embryonic development, asexual reproduction and regeneration require extensive remodeling of the extracellular matrix (ECM). We used the simple metazoan Hydra to examine the fate of ECM during tissue morphogenesis and asexual budding. In growing Hydra, epithelial cells constantly move towards the extremities of the animal and into outgrowing buds. It is not known, whether these tissue movements involve epithelial migration relative to the underlying matrix or whether cells and ECM are displaced as a composite structure. Furthermore, it is unclear, how the ECM is remodeled to adapt to the shape of developing buds and tentacles. To address these questions, we used a new in vivo labeling technique for Hydra collagen-1 and laminin, and tracked the fate of ECM in all body regions of the animal. Our results reveal that Hydra 'tissue movements' are largely displacements of epithelial cells together with associated ECM. By contrast, during the evagination of buds and tentacles, extensive movement of epithelial cells relative to the matrix is observed, together with local ECM remodeling. These findings provide new insights into the nature of growth and morphogenesis in epithelial tissues.

  19. Type VII collagen in Alport syndrome.

    Science.gov (United States)

    Giannakakis, Konstantinos; Massella, Laura; Grassetti, Daniele; Dotta, Francesco; Perez, Marie; Muda, Andrea Onetti

    2007-12-01

    Absence or segmental distribution of the alpha5(IV) collagen chain along the epidermal basement membrane (EBM) is diagnostic of X-linked Alport syndrome (X-AS), but the typical morphologic alterations usually observed along the glomerular basement membrane (GBM) are lacking. However, several differences in protein composition exist between GBM and EBM, and such differences could account for a different phenotype with the same genetic defect. Type VII collagen is one of the major collagenous components of the EBM; the purpose of this study was to investigate the modifications of protein synthesis and expression of type VII collagen in the skin of patients with X-AS. The distribution of type VII collagen has been studied in 15 skin biopsies (10 from X-AS patients and 5 controls) by means of electron microscopy, immunofluorescence and confocal microscopy; type VII collagen mRNA expression was also measured by RT-PCR on the same skin fragments. Protein and mRNA amounts for type VII collagen were significantly higher in skin samples from X-AS patients than in controls (P < 0.001); highest values were in cases in which alpha5(IV) was completely absent. Our results indicate that lack of alpha5(IV) molecule significantly alters the assembly of extracellular matrix molecules other than alphax(IV) chains also at the EBM level. We suggest that the increased synthesis and deposition of type VII collagen is likely to balance the absence of stabilizing activity normally exerted by alpha5(IV).

  20. An immunohistochemical study of basement membrane heparan sulfate proteoglycan (perlecan) in oral epithelial dysplasia and squamous cell carcinoma.

    Science.gov (United States)

    Mishra, Mithilesh; Chandavarkar, Vidyadevi; Naik, Veena V; Kale, Alka D

    2013-01-01

    Basement membrane heparan sulfate proteoglycan (perlecan) has been demonstrated in precancer lesions and carcinomas of oral cavity. It helps in malignant transformation of epithelial cells. The aim of our study was to understand the immuno-localization of perlecan in oral dysplastic epithelium and oral carcinomas. A total of 50 cases comprising 10 normal mucosa, 20 dysplastic mucosa, and 20 oral squamous cell carcinomas (OSCC) were included in the retrospective study. They were examined for the presence of perlecan protein core by immunohistochemistry using monoclonal antibody. Interpretation of the pattern of staining was done, and majority of the observations were taken for statistical analysis. In normal epithelium, perlecan was found to be present in basal layer at the cell border. In dysplastic epithelium, it was present in suprabasal layers also. With the increase in severity of dysplasia, its expression was more in suprabasal layers, and the immuno-localization was found to be at cell border and cytoplasm. In OSCC cases, perlecan was present in stroma and tumor islands. It was deduced from the above results that perlecan helps potentially in dysplastic changes of epithelial cells. It gets accumulated within the cell and intercellular spaces and serves as a reservoir for various growth factors. In OSCC, it breaks down and releases growth factors, which help in tumor progression, angiogenesis, and metastasis of the carcinoma.

  1. Skin Basement Membrane: The Foundation of Epidermal Integrity—BM Functions and Diverse Roles of Bridging Molecules Nidogen and Perlecan

    Directory of Open Access Journals (Sweden)

    Dirk Breitkreutz

    2013-01-01

    Full Text Available The epidermis functions in skin as first defense line or barrier against environmental impacts, resting on extracellular matrix (ECM of the dermis underneath. Both compartments are connected by the basement membrane (BM, composed of a set of distinct glycoproteins and proteoglycans. Herein we are reviewing molecular aspects of BM structure, composition, and function regarding not only (i the dermoepidermal interface but also (ii the resident microvasculature, primarily focusing on the per se nonscaffold forming components perlecan and nidogen-1 and nidogen-2. Depletion or functional deficiencies of any BM component are lethal at some stage of development or around birth, though BM defects vary between organs and tissues. Lethality problems were overcome by developmental stage- and skin-specific gene targeting or by cell grafting and organotypic (3D cocultures of normal or defective cells, which allows recapitulating BM formation de novo. Thus, evidence is accumulating that BM assembly and turnover rely on mechanical properties and composition of the adjacent ECM and the dynamics of molecular assembly, including further “minor” local components, nidogens largely functioning as catalysts or molecular adaptors and perlecan as bridging stabilizer. Collectively, orchestration of BM assembly, remodeling, and the role of individual players herein are determined by the developmental, tissue-specific, or functional context.

  2. Basement membrane and vascular remodelling in smokers and chronic obstructive pulmonary disease: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Muller H Konrad

    2010-07-01

    Full Text Available Abstract Background Little is known about airway remodelling in bronchial biopsies (BB in smokers and chronic obstructive pulmonary disease (COPD. We conducted an initial pilot study comparing BB from COPD patients with nonsmoking controls. This pilot study suggested the presence of reticular basement membrane (Rbm fragmentation and altered vessel distribution in COPD. Methods To determine whether Rbm fragmentation and altered vessel distribution in BB were specific for COPD we designed a cross-sectional study and stained BB from 19 current smokers and 14 ex-smokers with mild to moderate COPD and compared these to 15 current smokers with normal lung function and 17 healthy and nonsmoking subjects. Results Thickness of the Rbm was not significantly different between groups; although in COPD this parameter was quite variable. The Rbm showed fragmentation and splitting in both current smoking groups and ex-smoker COPD compared with healthy nonsmokers (p Conclusions Airway remodelling in smokers and mild to moderate COPD is associated with fragmentation of the Rbm and altered distribution of vessels in the airway wall. Rbm fragmentation was also present to as great an extent in ex-smokers with COPD. These characteristics may have potential physiological consequences.

  3. Suppression of Apoptosis by Basement Membrane Requires three-dimensional Tissue Organization and Withdrawal from the Cell Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Boudreau, N.; Werb, Z.; Bissell, M.J.

    1995-12-28

    The basement membrane (BM) extracellular matrix induces differentiation and suppresses apoptosis in mammary epithelial cells, whereas cells lacking BM lose their differentiated phenotype and undergo apoptosis. Addition of purified BM components, which are known to induce {beta}-casein expression, did not prevent apoptosis, indicating that a more complex BM was necessary. A comparison of culture conditions where apoptosis would or would not occur allowed us to relate inhibition of apoptosis to a complete withdrawal from the cell cycle, which was observed only when cells acquired a three-dimensional alveolar structure in response to BM. In the absence of this morphology, both the G1 cyclin kinase inhibitor p21/WAF-I and positive proliferative signals including c-myc and cyclin Dl were expressed and the retinoblastoma protein (Rb) continued to be hyperphosphorylated. When we overexpressed either c-myc in quiescent cells or p21 when cells were still cycling, apoptosis was induced. In the absence of three-dimensional alveolar structures, mammary epithelial cells secrete a number of factors including transforming growth factor a and tenascin, which when added exogenously to quiescent cells induced expression of c-myc and interleukin-{beta}1-converting enzyme (ICE) mRNA and led to apoptosis. These experiments demonstrate that a correct tissue architecture is crucial for long-range homeostasis, suppression of apoptosis, and maintenance of differentiated phenotype.

  4. Giant cell tubulitis with tubular basement membrane immune deposits: a report of two cases after cardiac valve replacement surgery.

    Science.gov (United States)

    Chang, Anthony; Peutz-Kootstra, Carine J; Kowalewska, Jolanta; Logar, Christine M; Gitomer, Jeremy J; Davis, Connie L; Shankland, Stuart J; Alpers, Charles E; Smith, Kelly D

    2006-09-01

    This paper presents two elderly patients who had normal baseline renal function and had stenotic valvular lesions secondary to rheumatic fever and underwent aortic valve replacements with mechanical valves. Both patients developed acute renal failure after cardiac valve replacement procedures. The renal biopsies revealed acute granulomatous tubulointerstitial nephritis. The unique histologic features were tubular basement membrane (TBM) immune complex deposition detected by both immunofluorescence and electron microscopy and prominent multinucleated giant cells surrounding intact TBM. The temporal relationship to the surgical procedure and the subsequent recovery of the patients' renal functions upon therapy suggested that the renal failure may have been due to an allergic drug reaction from the perioperative exposure to unknown agents, such as prophylactic antibiotics and furosemide. The literature on TBM immune complex deposition was reviewed, and the pathophysiologic mechanisms that may account for the similarities between the clinicopathologic features of these two cases were examined. These two cases expand the histopathologic spectrum of previously described cases of putative drug-induced acute tubulointerstitial nephritis.

  5. Colorectal laterally spreading tumors show characteristic expression of cell polarity factors, including atypical protein kinase C λ/ι, E-cadherin, β-catenin and basement membrane component.

    Science.gov (United States)

    Ichikawa, Yasushi; Nagashima, Yoji; Morioka, Kaori; Akimoto, Kazunori; Kojima, Yasuyuki; Ishikawa, Takashi; Goto, Ayumu; Kobayashi, Noritoshi; Watanabe, Kazuteru; Ota, Mitsuyoshi; Fujii, Shoichi; Kawamata, Mayumi; Takagawa, Ryo; Kunizaki, Chikara; Takahashi, Hirokazu; Nakajima, Atsushi; Maeda, Shin; Shimada, Hiroshi; Inayama, Yoshiaki; Ohno, Shigeo; Endo, Itaru

    2014-09-01

    Colorectal flat-type tumors include laterally spreading tumors (LSTs) and flat depressed-type tumors. The former of which shows a predominant lateral spreading growth rather than an invasive growth. The present study examined the morphological characteristics of LSTs, in comparison with polypoid- or flat depressed-type tumors, along with the expression of atypical protein kinase C (aPKC) λ/ι, a pivotal cell polarity regulator, and the hallmarks of cell polarity, as well as with type IV collagen, β-catenin and E-cadherin. In total, 37 flat-type (24 LSTs and 13 flat depressed-type tumors) and 20 polypoid-type colorectal tumors were examined. The LSTs were classified as 15 LST adenoma (LST-A) and nine LST cancer in adenoma (LST-CA). An immunohistochemical examination was performed on aPKC λ/ι, type IV collagen, β-catenin and E-cadherin. The LST-A and -CA showed a superficial replacing growth pattern, with expression of β-catenin and E-cadherin in the basolateral membrane and type IV collagen along the basement membrane. In addition, 86.6% of LST-A and 55.6% of LST-CA showed aPKC λ/ι expression of 1+ (weak to normal intensity staining in the cytoplasm compared with the normal epithelium). Furthermore, ~45% of the polypoid-type adenomas showed 2+ (moderate intensity staining in the cytoplasm and/or nucleus) and 66.7% of the polypoid-type cancer in adenoma were 3+ (strong intensity staining in the cytoplasm and nucleus). A statistically significant positive correlation was observed between the expression of aPKC λ/ι and β-catenin (r=0.842; P<0.001), or type IV collagen (r=0.823; P<0.001). The LSTs showed a unique growth pattern, different from the expanding growth pattern presented by a polypoid tumor and invasive cancer. The growth characteristics of LST appear to be caused by adequate coexpression of β-catenin, type IV collagen and aPKC λ/ι.

  6. Guided bone regeneration with asymmetric collagen-chitosan membranes containing aspirin-loaded chitosan nanoparticles.

    Science.gov (United States)

    Zhang, Jiayu; Ma, Shiqing; Liu, Zihao; Geng, Hongjuan; Lu, Xin; Zhang, Xi; Li, Hongjie; Gao, Chenyuan; Zhang, Xu; Gao, Ping

    2017-01-01

    Membranes allowing the sustained release of drugs that can achieve cell adhesion are very promising for guided bone regeneration. Previous studies have suggested that aspirin has the potential to promote bone regeneration. The purpose of this study was to prepare a local drug delivery system with aspirin-loaded chitosan nanoparticles (ACS) contained in an asymmetric collagen-chitosan membrane (CCM). In this study, the ACS were fabricated using different concentrations of aspirin (5 mg, 25 mg, 50 mg, and 75 mg). The drug release behavior of ACS was studied. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to examine the micromorphology of ACS and aspirin-loaded chitosan nanoparticles contained in chitosan-collagen membranes (ACS-CCM). In vitro bone mesenchymal stem cells (BMSCs) were cultured and critical-sized cranial defects on Sprague-Dawley rats were made to evaluate the effect of the ACS-CCM on bone regeneration. Drug release behavior results of ACS showed that the nanoparticles fabricated in this study could successfully sustain the release of the drug. TEM showed the morphology of the nanoparticles. SEM images indicated that the asymmetric membrane comprised a loose collagen layer and a dense chitosan layer. In vitro studies showed that ACS-CCM could promote the proliferation of BMSCs, and that the degree of differentiated BMSCs seeded on CCMs containing 50 mg of ACS was higher than that of other membranes. Micro-computed tomography showed that 50 mg of ACS-CCM resulted in enhanced bone regeneration compared with the control group. This study shows that the ACS-CCM would allow the sustained release of aspirin and have further osteogenic potential. This membrane is a promising therapeutic approach to guiding bone regeneration.

  7. How to Study Basement Membrane Stiffness as a Biophysical Trigger in Prostate Cancer and Other Age-related Pathologies or Metabolic Diseases

    OpenAIRE

    Rodriguez-Teja, Mercedes; Breit, Claudia; Clarke, Mitchell; Talar, Kamil; Wang, Kai; Mohammad, Mohammad A.; Pickwell, Sage; Etchandy, Guillermina; Stasiuk, Graeme J.; Sturge, Justin

    2016-01-01

    Here we describe a protocol that can be used to study the biophysical microenvironment related to increased thickness and stiffness of the basement membrane (BM) during age-related pathologies and metabolic disorders (e.g. cancer, diabetes, microvascular disease, retinopathy, nephropathy and neuropathy). The premise of the model is non-enzymatic crosslinking of reconstituted BM (rBM) matrix by treatment with glycolaldehyde (GLA) to promote advanced glycation endproduct (AGE) generation via th...

  8. In vitro sealing of iatrogenic fetal membrane defects by a collagen plug imbued with fibrinogen and plasma.

    Science.gov (United States)

    Engels, A C; Hoylaerts, M F; Endo, M; Loyen, S; Verbist, G; Manodoro, S; DeKoninck, P; Richter, J; Deprest, J A

    2013-02-01

    We aimed to demonstrate local thrombin generation by fetal membranes, as well as its ability to generate fibrin from fibrinogen concentrate. Furthermore, we aimed to investigate the efficacy of collagen plugs, soaked with plasma and fibrinogen, to seal iatrogenic fetal membrane defects. Thrombin generation by homogenized fetal membranes was measured by calibrated automated thrombography. To identify the coagulation caused by an iatrogenic membrane defect, we analyzed fibrin formation by optical densitometry, upon various concentrations of fibrinogen. The ability of a collagen plug soaked with fibrinogen and plasma was tested in an ex vivo model for its ability to seal an iatrogenic fetal membrane defect. Fetal membrane homogenates potently induced thrombin generation in amniotic fluid and diluted plasma. Upon the addition of fibrinogen concentrate, potent fibrin formation was triggered. Measured by densiometry, fibrin formation was optimal at 1250 µg/mL fibrinogen in combination with 4% plasma. A collagen plug soaked with fibrinogen and plasma sealed an iatrogenic membrane defect about 35% better than collagen plugs without these additives (P = 0.037). These in vitro experiments suggest that the addition of fibrinogen and plasma may enhance the sealing efficacy of collagen plugs in closing iatrogenic fetal membrane defects. © 2013 John Wiley & Sons, Ltd.

  9. Collagen-chitosan-glycerol bio-composite as artificial tympanic membrane for ruptured inner ear organ

    Science.gov (United States)

    Widiyanti, Prihartini; Setya Angtika, Rara; Githanadi, Brillyana; Hanif Kharisma, Ditya; Asyraf, Tarikh Omar; Wardani, Adita

    2017-05-01

    WHO data in 2012 shows that 5.3% of world population highly suffers from hearing loss and deafness. One of the deafness causes is rupture of tympanic membrane. Tympanic membrane damage which occurs often is perforated tympanic membrane, and it is also commonly known in medical term as tympanic membrane perforation. The causes, for instance, are high frequency of using earphones, traumatic accidents, noise, bacteria, viruses, and infectious microorganism. Tympanoplasty becomes the only treatment that can be widely accepted despite of deficiencies in postoperative complications. Therefore, this research aims to create artificial tympanic membrane made of natural materials such as type I collagen composited with chitosan and made of addition of glycerol to improve its mechanical strength and biodegradability. The method included the process of dissolving acetic acid in distilled water and mixation with chitosan. The solution is next added with glycerol and stirred to be homogeneous. After that, it was minted in petri dish and aerated before characterized. The sample characterization included tensile strength of which tensile test results showed that the value of the elasticity modulus tended to decrease with an increase in collagen concentration. The elasticity modulus values in a row for the variations of 7: 3, 8: 2, and 9: 1 were 35.10 MPa, 54,52MPa, and 47,45MPa respectively. The morphological test with 1000x, 2500x, and 5000x magnification showed their interaction in the formation of pores. Cytotoxicity results, moreover, showed that those samples were non-toxic and safe for the body due to the percentage of living cells. The sound absorption coefficient was between 1000 Hz - 2000 Hz which means that it could use as sound absorbing material. The antibacterial test results showed that all the sample variations were anti-bacterial due to the diameter of the clear zone. In conclusion, collagen and chitosan composite with addition of glycerol could be used for

  10. Evaluating adhesion reduction efficacy of type I/III collagen membrane and collagen-GAG resorbable matrix in primary flexor tendon repair in a chicken model.

    Science.gov (United States)

    Turner, John B; Corazzini, Rubina L; Butler, Timothy J; Garlick, David S; Rinker, Brian D

    2015-09-01

    Reduction of peritendinous adhesions after injury and repair has been the subject of extensive prior investigation. The application of a circumferential barrier at the repair site may limit the quantity of peritendinous adhesions while preserving the tendon's innate ability to heal. The authors compare the effectiveness of a type I/III collagen membrane and a collagen-glycosaminoglycan (GAG) resorbable matrix in reducing tendon adhesions in an experimental chicken model of a "zone II" tendon laceration and repair. In Leghorn chickens, flexor tendons were sharply divided using a scalpel and underwent repair in a standard fashion (54 total repairs). The sites were treated with a type I/III collagen membrane, collagen-GAG resorbable matrix, or saline in a randomized fashion. After 3 weeks, qualitative and semiquantitative histological analysis was performed to evaluate the "extent of peritendinous adhesions" and "nature of tendon healing." The data was evaluated with chi-square analysis and unpaired Student's t test. For both collagen materials, there was a statistically significant improvement in the degree of both extent of peritendinous adhesions and nature of tendon healing relative to the control group. There was no significant difference seen between the two materials. There was one tendon rupture observed in each treatment group. Surgical handling characteristics were subjectively favored for type I/III collagen membrane over the collagen-GAG resorbable matrix. The ideal method of reducing clinically significant tendon adhesions after injury remains elusive. Both materials in this study demonstrate promise in reducing tendon adhesions after flexor tendon repair without impeding tendon healing in this model.

  11. Dynamic interplay between the collagen scaffold and tumor evolution

    DEFF Research Database (Denmark)

    Egeblad, Mikala; Rasch, Morten G; Weaver, Valerie M

    2010-01-01

    and remodeling of the ECM network regulate tissue tension, generate pathways for migration, and release ECM protein fragments to direct normal developmental processes such as branching morphogenesis. Collagens are major components of the ECM of which basement membrane type IV and interstitial matrix type I...... are the most prevalent. Here we discuss how abnormal expression, proteolysis and structure of these collagens influence cellular functions to elicit multiple effects on tumors, including proliferation, initiation, invasion, metastasis, and therapy response....

  12. Intraepithelial expression of perlecan, a basement membrane-type heparan sulfate proteoglycan reflects dysplastic changes of the oral mucosal epithelium.

    Science.gov (United States)

    Ikarashi, Terué; Ida-Yonemochi, Hiroko; Ohshiro, Kazufumi; Cheng, Jun; Saku, Takashi

    2004-02-01

    Intercellular deposition of perlecan, a major heparan sulfate proteoglycan (HSPG) of the basement membrane, is known to result in characteristic stellate reticulum-like structures in ameloblastomas or tooth germs. Although enlargement of the intercellular space is one of the histological characteristics of epithelial dysplasia of oral mucosa, the mode of expression of perlecan is poorly understood in these epithelial lesions. Eighty-two biopsy specimens consisting of normal and hyperplastic epithelium, epithelial dysplasia, and squamous cell carcinomas were examined for both perlecan core protein and heparan sulfate (HS) chains by immunohistochemistry and in situ hybridization. In normal and hyperplastic epithelium, perlecan core protein and HS chains were localized in the cell border of parabasal cells and lower prickle cells, and HS chains were also found in basal cells. With an increase in the severity of epithelial dysplasia, the core protein was heavily and extensively deposited in the interepithelial space as well as in the cytoplasm of epithelial cells from the basal to the surface layers. Its gene expression was confirmed in the cells around the protein deposits. On the other hand, HS chains were enhanced in mild dysplasia, but decreased in moderate and severe dysplasias. In squamous cell carcinomas, either the core protein or HS chains were found scarcely in tumor cells but abundantly in the stromal space. The findings indicate that perlecan is localized in the intercellular space of the oral epithelia, and that it is over-expressed in dysplastic epithelial cells and is deposited in their interepithelial space, which results in the histology of reduction of cellular cohesion.

  13. PF-1355, a mechanism-based myeloperoxidase inhibitor, prevents immune complex vasculitis and anti-glomerular basement membrane glomerulonephritis.

    Science.gov (United States)

    Zheng, Wei; Warner, Roscoe; Ruggeri, Roger; Su, Chunyan; Cortes, Christian; Skoura, Athanasia; Ward, Jessica; Ahn, Kay; Kalgutkar, Amit; Sun, Dexue; Maurer, Tristan S; Bonin, Paul D; Okerberg, Carlin; Bobrowski, Walter; Kawabe, Thomas; Zhang, Yanwei; Coskran, Timothy; Bell, Sammy; Kapoor, Bhupesh; Johnson, Kent; Buckbinder, Leonard

    2015-05-01

    Small vessel vasculitis is a life-threatening condition and patients typically present with renal and pulmonary injury. Disease pathogenesis is associated with neutrophil accumulation, activation, and oxidative damage, the latter being driven in large part by myeloperoxidase (MPO), which generates hypochlorous acid among other oxidants. MPO has been associated with vasculitis, disseminated vascular inflammation typically involving pulmonary and renal microvasculature and often resulting in critical consequences. MPO contributes to vascular injury by 1) catabolizing nitric oxide, impairing vasomotor function; 2) causing oxidative damage to lipoproteins and endothelial cells, leading to atherosclerosis; and 3) stimulating formation of neutrophil extracellular traps, resulting in vessel occlusion and thrombosis. Here we report a selective 2-thiouracil mechanism-based MPO inhibitor (PF-1355 [2-(6-(2,5-dimethoxyphenyl)-4-oxo-2-thioxo-3,4-dihydropyrimidin-1(2H)-yl)acetamide) and demonstrate that MPO is a critical mediator of vasculitis in mouse disease models. A pharmacokinetic/pharmacodynamic response model of PF-1355 exposure in relation with MPO activity was derived from mouse peritonitis. The contribution of MPO activity to vasculitis was then examined in an immune complex model of pulmonary disease. Oral administration of PF-1355 reduced plasma MPO activity, vascular edema, neutrophil recruitment, and elevated circulating cytokines. In a model of anti-glomerular basement membrane disease, formerly known as Goodpasture disease, albuminuria and chronic renal dysfunction were completely suppressed by PF-1355 treatment. This study shows that MPO activity is critical in driving immune complex vasculitis and provides confidence in testing the hypothesis that MPO inhibition will provide benefit in treating human vasculitic diseases. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

  14. Lack of collagen XVIII/endostatin exacerbates immune-mediated glomerulonephritis.

    Science.gov (United States)

    Hamano, Yuki; Okude, Takashi; Shirai, Ryota; Sato, Ikumi; Kimura, Ryota; Ogawa, Makoto; Ueda, Yoshihiko; Yokosuka, Osamu; Kalluri, Raghu; Ueda, Shiro

    2010-09-01

    Collagen XVIII is a component of the highly specialized extracellular matrix associated with basement membranes of epithelia and endothelia. In the normal kidney, collagen XVIII is distributed throughout glomerular and tubular basement membranes, mesangial matrix, and Bowman's capsule. Proteolytic cleavage within its C-terminal domain releases the fragment endostatin, which has antiangiogenic properties. Because damage to the glomerular basement membrane (GBM) accompanies immune-mediated renal injury, we investigated the role of collagen XVIII/endostatin in this disorder. We induced anti-GBM glomerulonephritis in collagen XVIII alpha1-null and wild-type mice and compared the resulting matrix accumulation, inflammation, and capillary rarefaction. Anti-GBM disease upregulated collagen XVIII/endostatin expression within the GBM and Bowman's capsule of wild-type mice. Collagen XVIII/endostatin-deficient mice developed more severe glomerular and tubulointerstitial injury than wild-type mice. Collagen XVIII/endostatin deficiency altered matrix remodeling, enhanced the inflammatory response, and promoted capillary rarefaction and vascular endothelial cell damage, but did not affect endothelial proliferation. Supplementing collagen XVIII-deficient mice with exogenous endostatin did not affect the progression of anti-GBM disease. Taken together, these results suggest that collagen XVIII/endostatin preserves the integrity of the extracellular matrix and capillaries in the kidney, protecting against progressive glomerulonephritis.

  15. PDGF-metronidazole-encapsulated nanofibrous functional layers on collagen membrane promote alveolar ridge regeneration

    Directory of Open Access Journals (Sweden)

    Ho MH

    2017-08-01

    Full Text Available Ming-Hua Ho,1 Hao-Chieh Chang,2,3 Yu-Chia Chang,3 Jeiannete Claudia,1 Tzu-Chiao Lin,2 Po-Chun Chang2,3 1Department of Chemical Engineering, College of Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan; 2Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan; 3Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan Abstract: This study aimed to develop a functionally graded membrane (FGM to prevent infection and promote tissue regeneration. Poly(L-lactide-co-D,L-lactide encapsulating platelet-derived growth factor (PDLLA-PDGF or metronidazole (PDLLA-MTZ was electrospun to form a nanofibrous layer on the inner or outer surface of a clinically available collagen membrane, respectively. The membrane was characterized for the morphology, molecule release profile, in vitro and in vivo biocompatibility, and preclinical efficiency for alveolar ridge regeneration. The PDLLA-MTZ and PDLLA-PDGF nanofibers were 800–900 nm in diameter, and the thicknesses of the functional layers were 20–30 µm, with sustained molecule release over 28 days. All of the membranes tested were compatible with cell survival in vitro and showed good tissue integration with minimal fibrous capsule formation or inflammation. Cell proliferation was especially prominent on the PDLLA-PDGF layer in vivo. On the alveolar ridge, all FGMs reduced wound dehiscence compared with the control collagen membrane, and the FGM with PDLLA-PDGF promoted osteogenesis significantly. In conclusion, the FGMs with PDLLA-PDGF and PDLLA-MTZ showed high biocompatibility and facilitated wound healing compared with conventional membrane, and the FGM with PDLLA-PDGF enhanced alveolar ridge regeneration in vivo. The design represents a beneficial modification, which may be easily adapted for future clinical use. Keywords: tissue engineering, platelet-derived growth factor, metronidazole, alveolar process

  16. Physiochemical properties and resorption progress of porcine skin-derived collagen membranes: In vitro and in vivo analysis.

    Science.gov (United States)

    An, Yin-Zhe; Kim, You-Kyoung; Lim, Su-Min; Heo, Yeong-Ku; Kwon, Mi-Kyung; Cha, Jae-Kook; Lee, Jung-Seok; Jung, Ui-Won; Choi, Seong-Ho

    2018-03-30

    The aim of the present study was to evaluate the physiochemical properties and resorption progress of two cross-linked, porcine skin-derived collagen membranes and compare their features with those of a membrane without cross-linking (Bio-Gide ® [BG], Geistlich Biomaterials, Wolhusen, Switzerland). Three porcine skin-derived collagen membranes, dehydrothermally (DHT) cross-linked (experimental), DHT and 1-ethyl-3(3-dimethylaminopropyl)-carbodiimide (DHT/EDC) cross-linked (experimental) and BG were investigated for their morphology, enzyme resistance, and tensile strength in vitro and biodegradation in vivo. DHT and DHT/EDC membranes exhibited irregular, interconnected macro- and micropores that formed a 3D mesh, whereas BG exhibited individual collagen fibrils interlaced to form coarse collagen strands. In enzyme resistance and tensile strength tests, DHT and DHT/EDC membranes demonstrated good resistance and mechanical properties compared with BG. In vivo, all three membranes were well integrated into the surrounding connective tissue. Thus, the DHT membrane exhibited its potential as a barrier membrane for guided bone and tissue regeneration.

  17. Ubiquitin-Proteasome-Collagen (CUP Pathway in Preterm Premature Rupture of Fetal Membranes

    Directory of Open Access Journals (Sweden)

    Xinliang Zhao

    2017-06-01

    Full Text Available Spontaneous preterm birth (sPTB occurs before 37 gestational weeks, with preterm premature rupture of the membranes (PPROM and spontaneous preterm labor (sPTL as the predominant adverse outcomes. Previously, we identified altered expression of long non-coding RNAs (lncRNAs and message RNAs (mRNAs related to the ubiquitin proteasome system (UPS in human placentas following pregnancy loss and PTB. We therefore hypothesized that similar mechanisms might underlie PPROM. In the current study, nine pairs of ubiquitin-proteasome-collagen (CUP pathway–related mRNAs and associated lncRNAs were found to be differentially expressed in PPROM and sPTL. Pathway analysis showed that the functions of their protein products were inter-connected by ring finger protein. Twenty variants including five mutations were identified in CUP-related genes in sPTL samples. Copy number variations were found in COL19A1, COL28A1, COL5A1, and UBAP2 of sPTL samples. The results reinforced our previous findings and indicated the association of the CUP pathway with the development of sPTL and PPROM. This association was due not only to the genetic variation, but also to the epigenetic regulatory function of lncRNAs. Furthermore, the findings suggested that the loss of collagen content in PPROM could result from degradation and/or suppressed expression of collagens.

  18. Ridge Preservation Comparing a Nonresorbable PTFE Membrane to a Resorbable Collagen Membrane: A Clinical and Histologic Study in Humans.

    Science.gov (United States)

    Arbab, Hussain; Greenwell, Henry; Hill, Margaret; Morton, Dean; Vidal, Ricardo; Shumway, Brian; Allan, Nicholas D

    2016-02-01

    The primary aim of this randomized, controlled, blinded clinical trial was to compare the effect of a resorbable collagen membrane (CM group) versus a nonresorbable high-density polytetrafluoroethylene membrane (PTFE group) on the clinical and histologic outcomes of a ridge preservation procedure. All 24 sites received an intrasocket cancellous allograft and a buccal overlay bovine derived xenograft. The change in horizontal crestal ridge width was -1.4 ± 1.2 mm for the CM group, whereas the PTFE group lost -2.2 ± 1.5 mm, which was not statistically significant between groups (P > 0.05). Vertical ridge height change was -1.2 ± 1.5 for the CM group, whereas the PTFE group lost -0.5 ± 1.6, which was not significantly different between groups (P > 0.05). The percent vital bone was similar and not significantly different between groups. Primary closure was not obtained and the exposed membrane portion over the socket opening healed with keratinized tissue. The choice of a resorbable versus a nonresorbable barrier membrane did not affect the clinical or the histologic outcome of ridge preservation treatment.

  19. In vitro aging of mineralized collagen-based composite as guided tissue regeneration membrane

    International Nuclear Information System (INIS)

    Pan, S.X.; Li, Y.; Feng, H.L.; Bai, W.; Gu, Y.Y.

    2006-01-01

    The technique of guided tissue regeneration (GTR) has been developed for the regeneration of periodontal tissues, bone around natural teeth and dental implants. The aim of this study is to investigate the biodegradability and mechanic behavior of a novel mineralized nano-hydroxyapatite/collagen/poly (lactic acid) (nHAC/PLA) composite as GTR membrane in vitro. The elastic modulus and maximum tensile strength of GTR film samples with different nHAC/PLA ratio were measured to get an optimal nHAC/PLA ratio. Thermogravimetric analysis was conducted to evaluate the change of the inorganic component in the samples during the process of in vitro aging. Morphology of samples was checked by using scanning electron microscopy. On the basis of the above results, it can be concluded that the GTR membranes maintained integrity and the original appearance throughout the 1-month in vitro aging. There is an active dissolution and deposition process of crystals which is propitious to the bone formation on the surface of the composite membrane. The optimal nHAC/PLA ratio of the novel membrane is 0.4:1. For a longer period of bone repair, PLA with higher molecular weight should be chosen as the scaffold for the GTR membrane

  20. cDNA cloning of the basement membrane chondroitin sulfate proteoglycan core protein, bamacan: a five domain structure including coiled-coil motifs

    DEFF Research Database (Denmark)

    Wu, R R; Couchman, J R

    1997-01-01

    obtained cDNA clones encoding the entire bamacan core protein of Mr = 138 kD, which reveal a five domain, head-rod-tail configuration. The head and tail are potentially globular, while the central large rod probably forms coiled-coil structures, with one large central and several very short interruptions....../translation product from a full-length bamacan cDNA. The unusual structure of this proteoglycan is indicative of specific functional roles in basement membrane physiology, commensurate with its distinct expression in development and changes in disease models....

  1. Distribution, ultrastructural localization, and ontogeny of the core protein of a heparan sulfate proteoglycan in human skin and other basement membranes

    DEFF Research Database (Denmark)

    Horiguchi, Y; Couchman, J R; Ljubimov, A V

    1989-01-01

    A variety of heparan sulfate proteoglycans (HSPG) have been identified on cell surfaces and in basement membrane (BM). To more fully characterize HSPG in human skin BM, we used two monoclonal antibodies (MAb) directed against epitopes of the core protein of a high molecular weight HSPG isolated...... from murine EHS tumor. Indirect immunofluorescence revealed linear distribution of HSPG within all skin BM, and within BM of all other human organs investigated. In a study of the ontogeny of HSPG in human skin BM, HSPG was detectable as early as 54 gestational days, comparable with other ubiquitous BM...

  2. Effects of the bilayer nano-hydroxyapatite/mineralized collagen-guided bone regeneration membrane on site preservation in dogs.

    Science.gov (United States)

    Sun, Yi; Wang, Chengyue; Chen, Qixin; Liu, Hai; Deng, Chao; Ling, Peixue; Cui, Fu-Zhai

    2017-08-01

    This study was aimed at assessing the effects of the porous mineralized collagen plug with or without the bilayer mineralized collagen-guided bone regeneration membrane on alveolar ridge preservation in dogs. The third premolars in the bilateral maxilla of mongrel dogs ( N = 12) were extracted. Twenty-four alveolar sockets were thus randomly divided into three groups: membrane + collagen plug (MP, n = 8), nonmembrane + collagen plug (NP, n = 8) and blank group without any implantation (BG, n = 8). Radiographic assessment was carried out immediately and in the 2nd, 6th, and 12th week after surgery. The bone-repairing effects of the two grafts were respectively evaluated by clinical observation, X-ray micro-computed tomography examination, and histological analysis in the 8th and 12th week after surgery. Three groups presented excellent osseointegration without any inflammation or dehiscence. X-ray micro-computed tomography and histological assessment indicated that the ratios of new bone formation of MP group were significantly higher than those of NP group and BG group in the 8th and 12th week after surgery ( P guided bone regeneration membrane could reduce the absorption of alveolar ridge compared to BG group, and the combined use of porous mineralized collagen plug and bilayer mineralized collagen-guided bone regeneration could further improve the activity of bone regeneration.

  3. Graphene oxide improves the biocompatibility of collagen membranes in an in vitro model of human primary gingival fibroblasts.

    Science.gov (United States)

    De Marco, Patrizia; Zara, Susi; De Colli, Marianna; Radunovic, Milena; Lazović, Vladimir; Ettorre, Valeria; Di Crescenzo, Antonello; Piattelli, Adriano; Cataldi, Amelia; Fontana, Antonella

    2017-09-13

    Commercial collagen membranes are used in oral surgical procedures as scaffolds for bone deposition in guided bone regeneration. Here, we have enriched them with graphene oxide (GO) via a simple non-covalent functionalization, exploiting the capacity of oxygenated carbon functional moieties of GO to interact through hydrogen bonding with collagen. In the present paper, the GO-coated membranes have been characterized in terms of stability, nano-roughness, biocompatibility and induction of inflammatory response in human primary gingival fibroblast cells. The obtained coated membranes are demonstrated not to leak GO in the bulk solution, and to change some features of the membrane, such as stiffness and adhesion between the membrane and the atomic force microscopy (AFM) tip. Moreover, the presence of GO increases the roughness and the total surface exposed to the cells, as demonstrated by AFM analyses. The obtained material is biocompatible, and does not induce inflammation in the tested cells.

  4. Stratum, a Homolog of the Human GEF Mss4, Partnered with Rab8, Controls the Basal Restriction of Basement Membrane Proteins in Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Olivier Devergne

    2017-02-01

    Full Text Available The basement membrane (BM, a sheet of extracellular matrix lining the basal side of epithelia, is essential for epithelial cell function and integrity, yet the mechanisms that control the basal restriction of BM proteins are poorly understood. In epithelial cells, a specialized pathway is dedicated to restrict the deposition of BM proteins basally. Here, we report the identification of a factor in this pathway, a homolog of the mammalian guanine nucleotide exchange factor (GEF Mss4, which we have named Stratum. The loss of Stratum leads to the missecretion of BM proteins at the apical side of the cells, forming aberrant layers in close contact with the plasma membrane. We found that Rab8GTPase acts downstream of Stratum in this process. Altogether, our results uncover the importance of this GEF/Rab complex in specifically coordinating the basal restriction of BM proteins, a critical process for the establishment and maintenance of epithelial cell polarity.

  5. Alveolar ridge preservation with deproteinized bovine bone graft and collagen membrane and delayed implants.

    Science.gov (United States)

    Pang, Chaoyuan; Ding, Yuxiang; Zhou, Hongzhi; Qin, Ruifeng; Hou, Rui; Zhang, Guoliang; Hu, Kaijin

    2014-09-01

    To evaluate clinically and radiographically an alveolar ridge, preservation technique with deproteinized bovine bone graft and absorbable collagen membrane and then restoration with delayed implants were done. The study included 30 patients. The trial group's sockets were filled with deproteinized bovine bone graft (Bio-Oss) and covered with absorbable collagen membrane (Bio-Gide). The control group's sockets healed without any treatment. Panoramic radiograph and computed tomography were taken immediately after graft and 3 and 6 months later to evaluate the height, width, and volume change of the alveolar ridge bone. Dental implants were inserted in all sockets at 6 months, and osseointegration condition was evaluated in the following 12 months. All sockets healed uneventfully. In the trial group, the mean (SD) height reduction of the alveolar ridge bone was 1.05 (0.24) mm at 3 months and 1.54 (0.25) mm at 6 months. The width reduction was 1.11 (0.13) mm at 3 months and 1.84 (0.35) mm at 6 months. Bone volume reduction was 193.79 (21.47) mm at 3 months and 262.06 (33.08) mm at 6 months. At the same trend, in the control group, the bone height reduction was 2.12 (0.15) mm at 3 months and 3.26 (0.29) mm at 6 months. The width reduction was 2.72 (0.19) mm at 3 months and 3.56 (0.28) mm at 6 months. Bone volume reduction was 252.19 (37.21) mm at 3 months and 342.32 (36.41) mm at 6 months. There was a significant difference in alveolar ridge bone height, width, and volume reduction in the 2 groups. The osseointegration condition had no significant difference between the 2 groups. This study suggested that the deproteinized bovine bone graft and absorbable collagen membrane were beneficial to preserve the alveolar ridge bone and had no influence on the osseointegration of delayed implant.

  6. Preparation and characterisation of Punica granatum pericarp aqueous extract loaded chitosan-collagen-starch membrane: role in wound healing process.

    Science.gov (United States)

    Amal, B; Veena, B; Jayachandran, V P; Shilpa, Joy

    2015-05-01

    Engineered scaffolds made from natural biomaterials are crucial elements in tissue engineering strategies. In this study, biological scaffold like chitosan-collagen-starch membrane (CCSM) loaded with the antibacterial agent, Punica granatum pericarp aqueous extract was explored for enhanced regeneration of epithelial tissue during wound healing. Collagen was extracted from Rachycentron canadum fish skin. Membranous scaffold was prepared by mixing collagen, starch and chitosan in a fixed proportion, loaded with aqueous extract of P. granatum and its anti-pseudomonal activity was studied. Morphological characterization by SEM and mechanical property like tensile strength of the membrane were studied. Excision wound of 2 cm(2) size was induced in Guinea pig and the effect of P. granatum extract loaded CCSM in wound healing was studied. The SEM image showed deep pores in the membrane and also possessed good tensile strength. Wound surface area was reduced prominently in the experimental group with P. granatum extract loaded CCSM when compared to the group with unloaded membrane and the one with no membrane. Punica granatum extract loaded CCSM has antipseudomonal property and supported enhanced epithelial cell proliferation without leaving a scar after wound healing. This has significant therapeutic application in membranous scaffold mediated skin repair and regeneration.

  7. Guided Bone Regeneration with Collagen Membranes and Particulate Graft Materials: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Wessing, Bastian; Lettner, Stefan; Zechner, Werner

    The aim of this meta-analysis was to evaluate different methods for guided bone regeneration using collagen membranes and particulate grafting materials in implant dentistry. An electronic database search and hand search were performed for all relevant articles dealing with guided bone regeneration in implant dentistry published between 1980 and 2014. Only randomized clinical trials and prospective controlled studies were included. The primary outcomes of interest were survival rates, membrane exposure rates, bone gain/defect reduction, and vertical bone loss at follow-up. A meta-analysis was performed to determine the effects of presence of membrane cross-linking, timing of implant placement, membrane fixation, and decortication. Twenty studies met the inclusion criteria. Implant survival rates were similar between simultaneous and subsequent implant placement. The membrane exposure rate of cross-linked membranes was approximately 30% higher than that of non-cross-linked membranes. The use of anorganic bovine bone mineral led to sufficient newly regenerated bone and high implant survival rates. Membrane fixation was weakly associated with increased vertical bone gain, and decortication led to higher horizontal bone gain (defect depth). Guided bone regeneration with particulate graft materials and resorbable collagen membranes is an effective technique for lateral alveolar ridge augmentation. Because implant survival rates for simultaneous and subsequent implant placement were similar, simultaneous implant placement is recommended when possible. Additional techniques like membrane fixation and decortication may represent beneficial implications for the practice.

  8. Chitosan nanoparticles enhance the antibacterial activity of chlorhexidine in collagen membranes used for periapical guided tissue regeneration.

    Science.gov (United States)

    Barreras, Uriel Soto; Méndez, Fernando Torres; Martínez, Rita Elizabeth Martínez; Valencia, Carolina Samano; Rodríguez, Panfilo Raymundo Martinez; Rodríguez, Juan Pablo Loyola

    2016-01-01

    Endodontic failure is mainly associated with the persistence of microbial infection in the root canal system and/or the periradicular area. Microorganisms and their toxins located in the root canal system may trigger apical periodontitis and tissue destruction. Tissue regeneration in periapical surgery by using membrane barriers has shown an improved healing and bone closure. However, bacterial membrane contamination is a main reason of failure. In this in vitro study, different brands of chlorhexidine, a combination of chitosan nanoparticles containing chlorhexidine were tested against Enterococcus faecalis on agar plate's cultures and infected collagen membranes. Our results indicated that chitosan nanoparticles acted synergistically with chlorhexidine, inhibiting and eliminating significantly a greater amount of colony former units in both BHI-agar cultures and infected collagen membranes. These results suggested that chitosan nanoparticles could be used to improve regenerative procedures in periapical surgery. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Patch tracheoplasty in body tissue engineering using collagenous connective tissue membranes (biosheets).

    Science.gov (United States)

    Satake, Ryosuke; Komura, Makoto; Komura, Hiroko; Kodaka, Tetsuro; Terawaki, Kan; Ikebukuro, Kenichi; Komuro, Hiroaki; Yonekawa, Hironobu; Hoshi, Kazuto; Takato, Tsuyoshi; Nakayama, Yasuhide

    2016-02-01

    Collagenous connective tissue membranes (biosheets) are useful for engineering cardiovascular tissue in tissue engineering. The aim was to evaluate the use of biosheets as a potential tracheal substitute material in vivo in a rabbit model. Group 1: Rectangular-shaped Gore-Tex (4×7mm) was implanted into a 3×6mm defect created in the midventral portion of the cervical trachea. Group 2: Rectangular-shaped dermis was implanted into a tracheotomy of similar size. Group 3: Biosheets were prepared by embedding silicone moulds in dorsal subcutaneous pouches in rabbits for 1month. Rectangular-shaped biosheets were implanted into a tracheotomy of similar size in an autologous fashion. All groups (each containing 10 animals) were sacrificed 4weeks after implantation. All materials maintained airway structure for up to 4weeks after implantation. Regenerative cartilage in implanted Biosheets in group 3 was confirmed by histological analysis. Tracheal epithelial regeneration occurred in the internal lumen of group 3. There were significant differences in the amounts of collagen type II and glycosaminoglycan between group 3 and group 1 or 2. We confirm that cartilage can self-regenerate onto an airway patch using Biosheets. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Periodontal Responses to Augmented Corticotomy with Collagen Membrane Application during Orthodontic Buccal Tipping in Dogs

    Science.gov (United States)

    Herr, Yeek; Kwon, Young-Hyuk; Kim, Seong-Hun; Kim, Eun-Cheol

    2014-01-01

    This prospective randomized split-mouth study was performed to examine the effects of absorbable collagen membrane (ACM) application in augmented corticotomy using deproteinized bovine bone mineral (DBBM), during orthodontic buccal tipping movement in the dog. After buccal circumscribing corticotomy and DBBM grafting into the decorticated area, flaps were repositioned and sutured on control sides. ACM was overlaid and secured with membrane tacks, on test sides only, and the flaps were repositioned and sutured. Closed coil springs were used to apply 200 g orthodontic force in the buccolingual direction on the second and third premolars, immediately after primary flap closure. The buccal tipping angles were 31.19 ± 14.60° and 28.12 ± 11.48° on the control and test sides, respectively. A mean of 79.5 ± 16.0% of the buccal bone wall was replaced by new bone on the control side, and on the test side 78.9 ± 19.5% was replaced. ACM application promoted an even bone surface. In conclusion, ACM application in augmented corticotomy using DBBM might stimulate periodontal tissue reestablishment, which is useful for rapid orthodontic treatment or guided bone regeneration. In particular, ACM could control the formation of mesenchymal matrix, facilitating an even bone surface. PMID:25276824

  11. Immunohistochemical localization of chondroitin sulfate, chondroitin sulfate proteoglycan, heparan sulfate proteoglycan, entactin, and laminin in basement membranes of postnatal developing and adult rat lungs

    DEFF Research Database (Denmark)

    Sannes, P L; Burch, K K; Khosla, J

    1993-01-01

    , and laminin. A monoclonal antibody specific for the glycosaminoglycan portion (CS) of CSPG and a monoclonal antibody against the core protein of CSPG were used in an immunoperoxidase sequence to stain extracellular matrix (ECM) components of pulmonary basement membranes (BMs). Anti-CS stained airway BM...... alveolar, airway, and vascular BMs, in addition to smooth muscle external laminae (EL), in the adult and developing rat. Immunostaining for CSPG required hyaluronidase digestion, whereas CS staining was lost with the same treatment. A polyclonal antibody to the core protein of HSPG was found...... with CSPG, except that entactin showed particular affinity for EL. These results offer a more detailed perspective on previous survey observations of CSPG, HSPG, and entactin in the rat lung, and describe the immunoreactivity of CS for the first time.(ABSTRACT TRUNCATED AT 250 WORDS)...

  12. In vitro blood-brain barrier models for drug research: state-of-the-art and new perspectives on reconstituting these models on artificial basement membrane platforms.

    Science.gov (United States)

    Banerjee, Jayati; Shi, Yejiao; Azevedo, Helena S

    2016-09-01

    In vitro blood-brain barrier (BBB) models are indispensable screening tools for obtaining early information about the brain-penetrating behaviour of promising drug candidates. Until now, in vitro BBB models have focused on investigating the interplay among cellular components of neurovascular units and the effect of fluidic sheer stress in sustaining normal BBB phenotype and functions. However, an area that has received less recognition is the role of the noncellular basement membrane (BM) in modulating BBB physiology. This review describes the state-of-the-art on in vitro BBB models relevant in drug discovery research and highlights their strengths, weaknesses and the utility potential of some of these models in testing the permeability of nanocarriers as vectors for delivering therapeutics to the brain. Importantly, our review also introduces a new concept of engineering artificial BM platforms for reconstituting BBB models in vitro. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Reciprocal interactions between Beta1-integrin and epidermal growth factor in three-dimensional basement membrane breast cultures: A different perspective in epithelial biology

    Energy Technology Data Exchange (ETDEWEB)

    Wang, F.; Weaver, V.M.; Petersen, O.W.; Larabell, C.A.; Dedhar, S.; Briand, P.; Lupu, R.; Bissell, M.J.

    1998-09-30

    Anchorage and growth factor independence are cardinal features of the transformed phenotype. Although it is logical that the two pathways must be coregulated in normal tissues to maintain homeostasis, this has not been demonstrated directly. We showed previously that down-modulation of {beta}1-integrin signaling reverted the malignant behavior of a human breast tumor cell line (T4-2) derived from phenotypically normal cells (HMT-3522) and led to growth arrest in a threedimensional (3D) basement membrane assay in which the cells formed tissue-like acini (14). Here, we show that there is a bidirectional cross-modulation of {beta}1-integrin and epidermal growth factor receptor (EGFR) signaling via the mitogenactivated protein kinase (MAPK) pathway. The reciprocal modulation does not occur in monolayer (2D) cultures. Antibodymediated inhibition of either of these receptors in the tumor cells, or inhibition of MAPK kinase, induced a concomitant downregulation of both receptors, followed by growth-arrest and restoration of normal breast tissue morphogenesis. Crossmodulation and tissue morphogenesis were associated with attenuation of EGF-induced transient MAPK activation. To specifically test EGFR and {beta}1-integrin interdependency, EGFR was overexpressed in nonmalignant cells, leading to disruption of morphogenesis and a compensatory up-regulation of {beta}1-integrin expression, again only in 3D. Our results indicate that when breast cells are spatially organized as a result of contact with basement membrane, the signaling pathways become coupled and bidirectional. They further explain why breast cells fail to differentiate in monolayer cultures in which these events are mostly uncoupled. Moreover, in a subset of tumor cells in which these pathways are misregulated but functional, the cells could be 'normalized' by manipulating either pathway.

  14. Effects of rhBMP-2 Loaded Titanium Reinforced Collagen Membranes on Horizontal Bone Augmentation in Dogs

    Directory of Open Access Journals (Sweden)

    Ki-Sun Lee

    2017-01-01

    Full Text Available The aim of this study was to evaluate the efficacy of growth factor loaded collagen membranes on new bone formation during horizontal bone augmentation. Mandibular defects (4 × 4 × 4 mm were surgically prepared in six male beagle dogs, which were then protected with one of three types of membranes: (1 titanium mesh, (2 titanium reinforced collagen, or (3 rhBMP-2 loaded titanium reinforced collagen. Animals were euthanized 8 and 16 weeks after surgery, and nondecalcified specimens were prepared and histomorphologically investigated to determine the degree of osteogenesis. Data were analyzed with Friedman test. With respect to the degree of osteogenesis at earlier stage (8 weeks after surgery, there was significantly higher new bone ratio in rhBMP-2 loaded membrane group (p>0.05. However, with respect to the long-term results (16 weeks after surgery, there were no significant differences among the three membranes (p>0.05. Based on histomorphometric analysis, there were no significant differences in horizontal bone gaining ratio (p>0.05.

  15. Evaluation and Comparison of the Biopathology of Collagen and Inflammation in the Extracellular Matrix of Oral Epithelial Dysplasias and Inflammatory Fibrous Hyperplasia Using Picrosirius Red Stain and Polarising Microscopy: A Preliminary Study

    OpenAIRE

    Varghese, Soma Susan; Sarojini, Sreenivasan Bargavan; George, Giju Baby; Vinod, Sankar; Mathew, Philips; Babu, Anulekh; Sebastian, Joseph

    2015-01-01

    Background: The role of tumour inflammation and the dysplastic epithelial-stromal interactions on the nature of collagen fibres in the extracellular matrix of dysplastic epithelium is not fully understood. The present study was aimed to evaluate and compare the inflammation and pathological stromal collagen (loosely packed thin disorganized collagen) present in mild, moderate and severe epithelial dysplasias with that of inflammatory fibrous hyperplasias. The basement membrane intactness of e...

  16. Toward guided tissue and bone regeneration: morphology, attachment, proliferation, and migration of cells cultured on collagen barrier membranes. A systematic review.

    NARCIS (Netherlands)

    Behring, J.; Junker, R.; Walboomers, X.F.; Chessnut, B.; Jansen, J.A.

    2008-01-01

    Collagen barrier membranes are frequently used in both guided tissue regeneration (GTR) and guided bone regeneration (GBR). Collagen used for these devices is available from different species and is often processed to alter the properties of the final product. This is necessary because unprocessed

  17. Products of the unc-52 gene in Caenorhabditis elegans are homologous to the core protein of the mammalian basement membrane heparan sulfate proteoglycan.

    Science.gov (United States)

    Rogalski, T M; Williams, B D; Mullen, G P; Moerman, D G

    1993-08-01

    Mutations in the unc-52 gene of Caenorhabditis elegans affect attachment of the myofilament lattice to the muscle cell membrane. Here, we demonstrate that the unc-52 gene encodes a nematode homolog of perlecan, the mammalian basement membrane heparan sulfate proteoglycan. The longest potential open reading frame of this gene encodes a 2482-amino-acid protein with a signal peptide and four domains. The first domain is unique to the unc-52 polypeptide, whereas the three remaining domains contain sequences found in the LDL receptor (domain II) laminin (domain III) and N-CAM (domain IV). We have identified three alternatively spliced transcripts that encode different carboxy-terminal sequences. The two larger transcripts encode proteins containing all or part of domain IV, whereas the smaller transcript encodes a shortened polypeptide that completely lacks domain IV. We have determined that the disorganized muscle phenotype observed in unc-52(st196) animals is caused by the insertion of a Tc1 transposon into domain IV. Two monoclonal antibodies that recognize an extracellular component of all contractile tissues in C. elegans fail to stain embryos homozygous for a lethal unc-52 allele. We have mapped the epitopes recognized by both monoclonal antibodies to a region of domain IV in the unc-52-encoded protein sequence.

  18. Use of a collagen membrane loaded with recombinant human bone morphogenetic protein-2 with collagen-binding domain for vertical guided bone regeneration.

    Science.gov (United States)

    Lai, Chun-Hua; Zhou, Lei; Wang, Zhong-Lei; Lu, Hai-Bin; Gao, Yan

    2013-07-01

    Vertical bone regeneration of severe atrophic alveolar ridges remains a challenging procedure in implant dentistry. The aim of this study, accordingly, is to use a rabbit vertical guided bone regeneration model to evaluate whether using a collagen membrane (CM) loaded with small doses of recombinant human bone morphogenetic protein-2 with collagen-binding domain (rhBMP-2/CBD) would enhance two-way vertical bone regeneration. In each of eight rabbits, four titanium cylinders were screwed in perforated slits made into the external cortical bones of the calvaria. The following four treatment modalities were randomly allocated: 1) cylinders filled with mineralized bone matrix and covered with CM/rhBMP-2/CBD; 2) cylinders filled with mineralized bone matrix and covered with CM/rhBMP-2; 3) cylinders filled with mineralized bone matrix and covered with CM alone; or 4) cylinders filled with mineralized bone matrix without a membrane cover. After 6 weeks, the new bones were examined by histologic analysis. Slender new bone trabeculae were observed in the superficial layer of the titanium cylinders covered with CM/rhBMP-2/CBD, and higher degrees of bone were observed in this group compared with the other three groups. The average area fraction of newly formed bone was significantly more in the CM/rhBMP-2/CBD group compared with the CM/rhBMP-2, CM, or the no membrane control groups (all P bone formation not only from the surface of the native bone, but also from the superficial structures. The augmented new bone, therefore, is improved in both quantity and quality.

  19. Evaluation of 3D printed PCL/PLGA/β-TCP versus collagen membranes for guided bone regeneration in a beagle implant model.

    Science.gov (United States)

    Won, J-Y; Park, C-Y; Bae, J-H; Ahn, G; Kim, C; Lim, D-H; Cho, D-W; Yun, W-S; Shim, J-H; Huh, J-B

    2016-10-07

    Here, we compared 3D-printed polycaprolactone/poly(lactic-co-glycolic acid)/β-tricalcium phosphate (PCL/PLGA/β-TCP) membranes with the widely used collagen membranes for guided bone regeneration (GBR) in beagle implant models. For mechanical property comparison in dry and wet conditions and cytocompatibility determination, we analyzed the rate and pattern of cell proliferation of seeded fibroblasts and preosteoblasts using the cell counting kit-8 assay and scanning electron microscopy. Osteogenic differentiation was verified using alizarin red S staining. At 8 weeks following implantation in vivo using beagle dogs, computed tomography and histological analyses were performed after sacrifice. Cell proliferation rates in vitro indicated that early cell attachment was higher in collagen than in PCL/PLGA/β-TCP membranes; however, the difference subsided by day 7. Similar outcomes were found for osteogenic differentiation, with approximately 2.5 times greater staining in collagen than PCL/PLGA/β-TCP, but without significant difference by day 14. In vivo, bone regeneration in the defect area, represented by new bone formation and bone-to-implant contact, paralleled those associated with collagen membranes. However, tensile testing revealed that whereas the PCL/PLGA/β-TCP membrane mechanical properties were conserved in both wet and dry states, the tensile property of collagen was reduced by 99% under wet conditions. Our results demonstrate in vitro and in vivo that PCL/PLGA/β-TCP membranes have similar levels of biocompatibility and bone regeneration as collagen membranes. In particular, considering that GBR is always applied to a wet environment (e.g. blood, saliva), we demonstrated that PCL/PLGA/β-TCP membranes maintained their form more reliably than collagen membranes in a wet setting, confirming their appropriateness as a GBR membrane.

  20. The collagen turnover profile is altered in patients with inguinal and incisional hernia

    DEFF Research Database (Denmark)

    Henriksen, Nadia A; Mortensen, Joachim H; Sorensen, Lars T

    2015-01-01

    BACKGROUND: Disturbed metabolism in the extracellular matrix (ECM) contributes to formation of abdominal wall hernias. The aim of this study was to gain deeper insight into the ECM turnover in hernia patients by analyzing serum biomarkers specifically reflecting collagen synthesis and breakdown......). Patients without hernias scheduled to undergo elective operation for gallstones (n = 18) served as controls. Whole venous blood was collected preoperatively. Biomarkers for synthesis of interstitial matrix (PINP, Pro-C3, P5CP) and basement membrane (P4NP) as well as corresponding degradation (C1M, C3M, C5M......, and C4M) were measured in serum by validated, solid-phase competitive assays. RESULTS: In inguinal hernia patients, the turnover of the interstitial matrix collagens type III (P turnover of the basement membrane collagen type IV...

  1. Cell cytoskeletal changes effected by static compressive stress lead to changes in the contractile properties of tissue regenerative collagen membranes

    Directory of Open Access Journals (Sweden)

    K Gellynck

    2013-06-01

    Full Text Available Static compressive stress can influence the matrix, which subsequently affects cell behaviour and the cell’s ability to further transform the matrix. This study aimed to assess response to static compressive stress at different stages of osteoblast differentiation and assess the cell cytoskeleton’s role as a conduit of matrix-derived stimuli. Mouse bone marrow mesenchymal stem cells (MSCs (D1 ORL UVA, osteoblastic cells (MC3T3-E1 and post-osteoblast/pre-osteocyte-like cells (MLO-A5 were seeded in hydrated and compressed collagen gels. Contraction was quantified macroscopically, and cell morphology, survival, differentiation and mineralisation assessed using confocal microscopy, alamarBlue® assay, real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR and histological stains, respectively. Confocal microscopy demonstrated cell shape changes and favourable microfilament organisation with static compressive stress of the collagen matrix; furthermore, cell survival was greater compared to the hydrated gels. The stage of osteoblast differentiation determined the degree of matrix contraction, with MSCs demonstrating the greatest amount. Introduction of microfilament disrupting inhibitors confirmed that pre-stress and tensegrity forces were under the influence of gel density, and there was increased survival and differentiation of the cells within the compressed collagen compared to the hydrated collagen. There was also relative stiffening and differentiation with time of the compressed cell-seeded collagen, allowing for greater manipulation. In conclusion, the combined collagen chemistry and increased density of the microenvironment can promote upregulation of osteogenic genes and mineralisation; MSCs can facilitate matrix contraction to form an engineered membrane with the potential to serve as a ‘pseudo-periosteum’ in the regeneration of bone defects.

  2. Zinc oxide-curcumin nanocomposite loaded collagen membrane as an effective material against methicillin-resistant coagulase-negative Staphylococci.

    Science.gov (United States)

    Soumya, K R; Snigdha, S; Sugathan, Sheela; Mathew, Jyothis; Radhakrishnan, E K

    2017-08-01

    Zinc oxide nanoparticles and curcumin are excellent antimicrobial agents. They have the potential to be used as alternative to antibiotics in wound infection management. In this study, ZnO-curcumin nanocomposite was synthesized and characterized. Physical adsorption of the nanocomposite onto collagen skin wound dressing was conducted and structural investigation was carried out by SEM. Antimicrobial assay, minimum inhibitory concentration (MIC), and viability assays of different concentrations of nanocomposite loaded collagen membrane were conducted against clinically isolated methicillin-resistant coagulase-negative Staphylococci (MRCoNS), such as S. epidermidis, S. hemolyticus, and S. saprophyticus. The nanocomposite showed excellent anti-CoNS activity on time kill assay with the MIC value of 195 µg/mL against S. epidermidis, S. hemolyticus and 390 µg/mL against S. saprophyticus. The nanocomposite loaded collagen membrane also showed excellent in vitro antistaphylococcal activity. This study may lead to the development of antibiotic alternate strategies to control and limit the MRCoNS in wound-related infections.

  3. Reduced fibulin-2 contributes to loss of basement membrane integrity and skin blistering in mice lacking integrin α3β1 in the epidermis.

    Science.gov (United States)

    Longmate, Whitney M; Monichan, Ruby; Chu, Mon-Li; Tsuda, Takeshi; Mahoney, My G; DiPersio, C Michael

    2014-06-01

    Deficient epidermal adhesion is a hallmark of blistering skin disorders and chronic wounds, implicating integrins as potential therapeutic targets. Integrin α3β1, a major receptor in the epidermis for adhesion to laminin-332 (LN-332), has critical roles in basement membrane (BM) organization during skin development. In the current study we identify a role for α3β1 in promoting stability of nascent epidermal BMs through induction of fibulin-2, a matrix-associated protein that binds LN-332. We demonstrate that mice lacking α3β1 in the epidermis display ruptured BM beneath neo-epidermis of wounds, characterized by extensive blistering. This junctional blistering phenocopies defects reported in newborn α3-null mice, as well as in human patients with α3 gene mutations, indicating that the developmental role of α3β1 in BM organization is recapitulated during wound healing. Mice lacking epidermal α3β1 also have reduced fibulin-2 expression, and fibulin-2-null mice display perinatal skin blisters similar to those in α3β1-deficient mice. Interestingly, α3-null wound epidermis or keratinocytes also show impaired processing of the LN-332 γ2 chain, although this defect was independent of reduced fibulin-2 and did not appear to cause blistering. Our findings indicate a role for integrin α3β1 in BM stability through fibulin-2 induction, both in neonatal skin and in adult wounds.

  4. A two-dimensional model of the colonic crypt accounting for the role of the basement membrane and pericryptal fibroblast sheath.

    Directory of Open Access Journals (Sweden)

    Sara-Jane Dunn

    Full Text Available The role of the basement membrane is vital in maintaining the integrity and structure of an epithelial layer, acting as both a mechanical support and forming the physical interface between epithelial cells and the surrounding connective tissue. The function of this membrane is explored here in the context of the epithelial monolayer that lines the colonic crypt, test-tube shaped invaginations that punctuate the lining of the intestine and coordinate a regular turnover of cells to replenish the epithelial layer every few days. To investigate the consequence of genetic mutations that perturb the system dynamics and can lead to colorectal cancer, it must be possible to track the emerging tissue level changes that arise in the crypt. To that end, a theoretical crypt model with a realistic, deformable geometry is required. A new discrete crypt model is presented, which focuses on the interaction between cell- and tissue-level behaviour, while incorporating key subcellular components. The model contains a novel description of the role of the surrounding tissue and musculature, based upon experimental observations of the tissue structure of the crypt, which are also reported. A two-dimensional (2D cross-sectional geometry is considered, and the shape of the crypt is allowed to evolve and deform. Simulation results reveal how the shape of the crypt may contribute mechanically to the asymmetric division events typically associated with the stem cells at the base. The model predicts that epithelial cell migration may arise due to feedback between cell loss at the crypt collar and density-dependent cell division, an hypothesis which can be investigated in a wet lab. This work forms the basis for investigation of the deformation of the crypt structure that can occur due to proliferation of cells exhibiting mutant phenotypes, experiments that would not be possible in vivo or in vitro.

  5. [Development of a novel absorbable nanofiber chitosan-collagen membrane by electrospinning and the preliminary study on guided bone regeneration].

    Science.gov (United States)

    Gao, B; Li, X J; Lin, M; Li, Y Y; Dong, Y

    2018-02-09

    Objective: To evaluate the application effect of nanofiber chitosan-collagen membrane (NCM) on guided bone regeneration (GBR). Methods: The mixture of collagen, chitosan, polyethylene oxide was used to make up the NCM by electrospinning, then the NCM was crosslinked by glutaraldehyde vapor. The physical property of the NCM was measured by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). MC3T3-E1 osteoblasts were cultured on NCM to characterize the biocompatibility. The effectiveness of four groups [contrast group, Bio-gide membrane (BGM), compressed chitosan-collagen menbrane (CCM), NCM/CCM] on bone regeneration were evaluated in critical-sized defects (diameter = 5 mm) in SD rats. Results: When the mixed solution consists of 4.0% collagen, 1.0% chitosan and 3.5% polyethylene oxide, the NCM could be validly fabricated by electrospinning. After cross-linking by glutaraldehyde vapor, the tensile strength and the stability of NCM in damp was enhanced. No cytotoxicity of the NCM was detected on MC3T3-E1 osteoblasts. In vivo study showed that the new bone regeneration ratio of NCM/CCM group was [(43.10±1.49)%], and this was similar to that of the group of BGM [(41.36±2.60)%] ( P> 0.05), but higher than that of the CCM group [(33.10±1.41)%] and the contrast group [(7.22±2.46)%] ( P< 0.05). Conclusions: The NCM can promote new bone regeneration effectively in GBR procedure.

  6. Membrane-associated 41-kDa GTP-binding protein in collagen-induced platelet activation

    International Nuclear Information System (INIS)

    Walker, G.; Bourguignon, L.Y.

    1990-01-01

    Initially we established that the binding of collagen to human blood platelets stimulates both the rapid loss of PIP2 and the generation of inositol-4,5-bisphosphate (IP2) and inositol-1,4,5-triphosphate (IP3). These results indicate that the binding of collagen stimulates inositol phospholipid-specific phospholipase C during platelet activation. The fact that GTP or GTP-gamma-S augments, and pertussis toxin inhibits, collagen-induced IP3 formation suggests that a GTP-binding protein or (or proteins) may be directly involved in the regulation of phospholipase C-mediated phosphoinositide turnover in human platelets. We have used several complementary techniques to isolate and characterize a platelet 41-kDa polypeptide (or polypeptides) that has a number of structural and functional similarities to the regulatory alpha i subunit of the GTP-binding proteins isolated from bovine brain. This 41-kDa polypeptide (or polypeptides) is found to be closely associated with at least four membrane glycoproteins (e.g., gp180, gp110, gp95, and gp75) in a 330-kDa complex that can be dissociated by treatment with high salt plus urea. Most important, we have demonstrated that antilymphoma 41-kDa (alpha i subunit of GTP-binding proteins) antibody cross-reacts with the platelet 41-kDa protein (or proteins) and the alpha i subunit of bovine brain Gi alpha proteins, and blocks GTP/collagen-induced IP3 formation. These data provide strong evidence that the 41-kDa platelet GTP-binding protein (or proteins) is directly involved in collagen-induced signal transduction during platelet activation

  7. Membrane-associated 41-kDa GTP-binding protein in collagen-induced platelet activation

    Energy Technology Data Exchange (ETDEWEB)

    Walker, G.; Bourguignon, L.Y. (Univ. of Miami Medical School, FL (USA))

    1990-08-01

    Initially we established that the binding of collagen to human blood platelets stimulates both the rapid loss of PIP2 and the generation of inositol-4,5-bisphosphate (IP2) and inositol-1,4,5-triphosphate (IP3). These results indicate that the binding of collagen stimulates inositol phospholipid-specific phospholipase C during platelet activation. The fact that GTP or GTP-gamma-S augments, and pertussis toxin inhibits, collagen-induced IP3 formation suggests that a GTP-binding protein or (or proteins) may be directly involved in the regulation of phospholipase C-mediated phosphoinositide turnover in human platelets. We have used several complementary techniques to isolate and characterize a platelet 41-kDa polypeptide (or polypeptides) that has a number of structural and functional similarities to the regulatory alpha i subunit of the GTP-binding proteins isolated from bovine brain. This 41-kDa polypeptide (or polypeptides) is found to be closely associated with at least four membrane glycoproteins (e.g., gp180, gp110, gp95, and gp75) in a 330-kDa complex that can be dissociated by treatment with high salt plus urea. Most important, we have demonstrated that antilymphoma 41-kDa (alpha i subunit of GTP-binding proteins) antibody cross-reacts with the platelet 41-kDa protein (or proteins) and the alpha i subunit of bovine brain Gi alpha proteins, and blocks GTP/collagen-induced IP3 formation. These data provide strong evidence that the 41-kDa platelet GTP-binding protein (or proteins) is directly involved in collagen-induced signal transduction during platelet activation.

  8. Extraction Socket Preservation Using Porcine-Derived Collagen Membrane Alone or Associated with Porcine-Derived Bone. Clinical Results of Randomized Controlled Study

    Directory of Open Access Journals (Sweden)

    Renzo Guarnieri

    2017-03-01

    Full Text Available Objectives: The aim of present randomized controlled clinical trial was to clinically evaluate hard tissue changes after extraction socket preservation procedures compared to natural spontaneous healing. Material and Methods: Thirty patients were enrolled in the present study and underwent single-tooth extraction in the premolar/molar areas. Ten sites were grafted with porcine-derived bone covered by collagen membrane, 10 covered by porcine-derived collagen membrane alone, and 10 underwent natural spontaneous healing. Vertical and horizontal bone changes after 3-month were evaluated at implant placement. Results: The vertical and horizontal bone changes at the extraction sockets treated with collagen membrane alone (vertical: -0.55 [SD 0.11] mm, and horizontal: -1.21 [SD 0.69] mm and collagen membrane plus porcine-derived bone (vertical: -0.37 [SD 0.7] mm, and horizontal: -0.91 [SD 0.53] mm were found significantly lower (P < 0.001, when compared to non-grafted sockets (vertical: -2.09 [SD 0.19] mm, and horizontal: -3.96 [SD 0.87] mm. In type 1 extraction sockets, in premolar sites, and in presence of vestibular bone thicknesses ≥ 1.5 mm, the use of collagen membrane alone revealed similar outcomes to those with additional graft material. Conclusions: At the re-entry surgery, extraction sockets grafted with porcine-derived bone and covered by collagen membrane, and extraction sockets covered by porcine-derived collagen membrane alone, showed significantly lower vertical and horizontal bone changes, compared to extraction sockets sites underwent natural spontaneous healing. However, a complete prevention of remodelling is not achievable, irrespective of the technique used.

  9. A novel urinary biomarker of type VI collagen formation and endotrophin is associated with loss of kidney function in patients with diabetic nephropathy

    DEFF Research Database (Denmark)

    Genovese, Federica; Rasmussen, Daniel; Nielsen, Signe Holm

    2017-01-01

    -stage renal disease. Fibrosis is characterized by a dysregulated remodeling of the extracellular matrix (ECM). Collagen type VI (COL VI) is a crucial ECM molecule for the control of tissue organization. It is present at the interface of the glomerular basement membrane and interstitial matrix and its levels...

  10. The association of HLA-DQB1, -DQA1 and -DPB1 alleles with anti- glomerular basement membrane (GBM disease in Chinese patients

    Directory of Open Access Journals (Sweden)

    Zhou Xu-Jie

    2011-05-01

    Full Text Available Abstract Background Human leukocyte antigen (HLA alleles are associated with many autoimmune diseases, including anti-glomerular basement membrane (GBM disease. In our previous study, it was demonstrated that HLA-DRB1*1501 was strongly associated with anti-GBM disease in Chinese. However, the association of anti-GBM disease and other HLA class II genes, including HLA-DQB1, -DQA1,-DPB1 alleles, has rarely been investigated in Asian, especially Chinese patients. The present study further analyzed the association between anti-GBM disease and HLA-DQB1, -DQA1, and -DPB1 genes. Apart from this, we tried to locate the potential risk amino acid residues of anti-GBM disease. Methods This study included 44 Chinese patients with anti-GBM disease and 200 healthy controls. The clinical and pathological data of the patients were collected and analyzed. Typing of HLA-DQB1, -DQA1 and -DPB1 alleles were performed by bi-directional sequencing of exon 2 using the SeCoreTM Sequencing Kits. Results Compared with normal controls, the prevalence of HLA-DPB1*0401 was significantly lower in patients with anti-GBM disease (3/88 vs. 74/400, p = 4.4 × 10-4, pc = 0.039. Comparing with normal controls, the combination of presence of DRB1*1501 and absence of DPB1*0401 was significantly prominent among anti-GBM patients (p = 2.0 × 10-12, pc = 1.7 × 10-10. Conclusions HLA-DPB1*0401 might be a protective allele to anti-GBM disease in Chinese patients. The combined presence of DRB1*1501 and absence of DPB1*0401 might have an even higher risk to anti-GBM disease than HLA-DRB1*1501 alone.

  11. Detection of gelatinolytic activity in developing basement membranes of the mouse embryo head by combining sensitive in situ zymography with immunolabeling.

    Science.gov (United States)

    Gkantidis, Nikolaos; Katsaros, Christos; Chiquet, Matthias

    2012-10-01

    Genetic evidence indicates that the major gelatinases MMP-2 and MMP-9 are involved in mammalian craniofacial development. Since these matrix metalloproteinases are secreted as proenzymes that require activation, their tissue distribution does not necessarily reflect the sites of enzymatic activity. Information regarding the spatial and temporal expression of gelatinolytic activity in the head of the mammalian embryo is sparse. Sensitive in situ zymography with dye-quenched gelatin (DQ-gelatin) has been introduced recently; gelatinolytic activity results in a local increase in fluorescence. Using frontal sections of wild-type mouse embryo heads from embryonic day 14.5-15.5, we optimized and validated a simple double-labeling in situ technique for combining DQ-gelatin zymography with immunofluorescence staining. MMP inhibitors were tested to confirm the specificity of the reaction in situ, and results were compared to standard SDS-gel zymography of tissue extracts. Double-labeling was used to show the spatial relationship in situ between gelatinolytic activity and immunostaining for gelatinases MMP-2 and MMP-9, collagenase 3 (MMP-13) and MT1-MMP (MMP-14), a major activator of pro-gelatinases. Strong gelatinolytic activity, which partially overlapped with MMP proteins, was confirmed for Meckel's cartilage and developing mandibular bone. In addition, we combined in situ zymography with immunostaining for extracellular matrix proteins that are potential gelatinase substrates. Interestingly, gelatinolytic activity colocalized precisely with laminin-positive basement membranes at specific sites around growing epithelia in the developing mouse head, such as the ducts of salivary glands or the epithelial fold between tongue and lower jaw region. Thus, this sensitive method allows to associate, with high spatial resolution, gelatinolytic activity with epithelial morphogenesis in the embryo.

  12. Poliomyelitis in MuLV-infected ICR-SCID mice after injection of basement membrane matrix contaminated with lactate dehydrogenase-elevating virus.

    Science.gov (United States)

    Carlson Scholz, Jodi A; Garg, Rohit; Compton, Susan R; Allore, Heather G; Zeiss, Caroline J; Uchio, Edward M

    2011-10-01

    The arterivirus lactate dehydrogenase-elevating virus (LDV) causes life-long viremia in mice. Although LDV infection generally does not cause disease, infected mice that are homozygous for the Fv1(n) allele are prone to develop poliomyelitis when immunosuppressed, a condition known as age-dependent poliomyelitis. The development of age-dependent poliomyelitis requires coinfection with endogenous murine leukemia virus. Even though LDV is a common contaminant of transplantable tumors, clinical signs of poliomyelitis after inadvertent exposure to LDV have not been described in recent literature. In addition, LDV-induced poliomyelitis has not been reported in SCID or ICR mice. Here we describe the occurrence of poliomyelitis in ICR-SCID mice resulting from injection of LDV-contaminated basement membrane matrix. After exposure to LDV, a subset of mice presented with clinical signs including paresis, which was associated with atrophy of the hindlimb musculature, and tachypnea; in addition, some mice died suddenly with or without premonitory signs. Mice presenting within the first 6 mo after infection had regions of spongiosis, neuronal necrosis and astrocytosis of the ventral spinal cord, and less commonly, brainstem. Axonal degeneration of ventral roots prevailed in more chronically infected mice. LDV was identified by RT-PCR in 12 of 15 mice with typical neuropathology; positive antiLDV immunolabeling was identified in all PCR-positive animals (n = 7) tested. Three of 8 mice with neuropathology but no clinical signs were LDV negative by RT-PCR. RT-PCR yielded murine leukemia virus in spinal cords of all mice tested, regardless of clinical presentation or neuropathology.

  13. Collagencin, an antibacterial peptide from fish collagen: Activity, structure and interaction dynamics with membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ennaas, Nadia [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada); Hammami, Riadh, E-mail: riadh.hammami@fsaa.ulaval.ca [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada); Gomaa, Ahmed [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada); Bédard, François; Biron, Éric [Faculty of Pharmacy, Université Laval and Laboratory of Medicinal Chemistry, CHU de Québec Research Centre, G1V 4G2 Québec, QC (Canada); Subirade, Muriel [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada); Beaulieu, Lucie, E-mail: lucie.beaulieu@fsaa.ulaval.ca [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada); Department of Biology, Chemistry and Geography, Université du Québec à Rimouski (UQAR), 300 Allée des Ursulines, Rimouski, QC G5L 3A1 (Canada); Fliss, Ismail, E-mail: ismail.fliss@fsaa.ulaval.ca [STELA Dairy Research Centre, Institute of Nutrition and Functional Foods, Université Laval, G1V 0A6 Québec, QC (Canada)

    2016-04-29

    In this study, we first report characterization of collagencin, an antimicrobial peptide identified from fish collagen hydrolysate. The peptide completely inhibited the growth of Staphylococcus aureus at 1.88 mM. Although non-toxic up to 470 μM, collagencin was hemolytic at higher concentrations. The secondary structure of collagencin was mainly composed by β-sheet and β-turn as determined by CD measurements and molecular dynamics. The peptide is likely to form β-sheet structure under hydrophobic environments and interacts with both anionic (phosphatidylglycerol) and zwitterionic (phosphoethanolamine and phosphatidylcholine) lipids as shown with CD spectroscopy and molecular dynamics. The peptide formed several hydrogen bonds with both POPG and POPE lipids and remained at membrane–water interface, suggesting that collagencin antibacterial action follows a carpet mechanism. Collagenous fish wastes could be processed by enzymatic hydrolysis and transformed into products of high value having functional or biological properties. Marine collagens are a promising source of antimicrobial peptides with new implications in food safety and human health. - Highlights: • Collagencin, an antibacterial (G+ & G-) peptide identified from fish collagen hydrolysate. • The peptide completely inhibited the growth of S. aureus at 1.88 mM and non-toxic at 470 μM. • The secondary structure was mainly composed by β-sheet and turn as determined by CD and MD. • Collagencin interacts with both anionic and zwitterionic lipids as shown with CD and MD. • Collagencin antibacterial action probably follows a carpet mechanism.

  14. Guided Bone Regeneration in Long-Bone Defects with a Structural Hydroxyapatite Graft and Collagen Membrane

    Science.gov (United States)

    2013-01-01

    collagen type I. The fibrous tissue area infiltration to total area was measured based on color mapping in BioquantOsteo to select the area of...to the differences in distribution of pulverized autograft across the defect space between different animals in the group. The wrap group showed...1885 suitable mechanical environment.23 In this study, we evalu- ate a strategy to improve the regenerative capacity of struc- tural osteoconductive

  15. How to Study Basement Membrane Stiffness as a Biophysical Trigger in Prostate Cancer and Other Age-related Pathologies or Metabolic Diseases.

    Science.gov (United States)

    Rodriguez-Teja, Mercedes; Breit, Claudia; Clarke, Mitchell; Talar, Kamil; Wang, Kai; Mohammad, Mohammad A; Pickwell, Sage; Etchandy, Guillermina; Stasiuk, Graeme J; Sturge, Justin

    2016-09-20

    Here we describe a protocol that can be used to study the biophysical microenvironment related to increased thickness and stiffness of the basement membrane (BM) during age-related pathologies and metabolic disorders (e.g. cancer, diabetes, microvascular disease, retinopathy, nephropathy and neuropathy). The premise of the model is non-enzymatic crosslinking of reconstituted BM (rBM) matrix by treatment with glycolaldehyde (GLA) to promote advanced glycation endproduct (AGE) generation via the Maillard reaction. Examples of laboratory techniques that can be used to confirm AGE generation, non-enzymatic crosslinking and increased stiffness in GLA treated rBM are outlined. These include preparation of native rBM (treated with phosphate-buffered saline, PBS) and stiff rBM (treated with GLA) for determination of: its AGE content by photometric analysis and immunofluorescent microscopy, its non-enzymatic crosslinking by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE) as well as confocal microscopy, and its increased stiffness using rheometry. The procedure described here can be used to increase the rigidity (elastic moduli, E) of rBM up to 3.2-fold, consistent with measurements made in healthy versus diseased human prostate tissue. To recreate the biophysical microenvironment associated with the aging and diseased prostate gland three prostate cell types were introduced on to native rBM and stiff rBM: RWPE-1, prostate epithelial cells (PECs) derived from a normal prostate gland; BPH-1, PECs derived from a prostate gland affected by benign prostatic hyperplasia (BPH); and PC3, metastatic cells derived from a secondary bone tumor originating from prostate cancer. Multiple parameters can be measured, including the size, shape and invasive characteristics of the 3D glandular acini formed by RWPE-1 and BPH-1 on native versus stiff rBM, and average cell length, migratory velocity and persistence of cell movement of 3D spheroids formed by PC3 cells under

  16. Pulmonary renal syndrome in a child with coexistence of anti-neutrophil cytoplasmic antibodies and anti-glomerular basement membrane disease: case report and literature review.

    Science.gov (United States)

    Bogdanović, Radovan; Minić, Predrag; Marković-Lipkovski, Jasmina; Stajić, Nataša; Savić, Nataša; Rodić, Milan

    2013-03-22

    Pulmonary renal syndrome (PRS), denoting the presence of diffuse alveolar hemorrhage and glomerulonephritis as manifestations of systemic autoimmune disease, is very rare in childhood. The coexistence of circulating anti-neutrophil cytoplasmic antibody (ANCA) and anti-glomerular basement membrane (GBM) disease in children affected by this syndrome is exceptional, with unfavorable outcome in five out of seven patients reported to date. We describe a child with PRS associated with both circulating anti-myeloperoxidase (anti-MPO) ANCA and anti-GBM disease on renal biopsy who was successfully treated with immunosuppressive therapy. A 10-year old girl presented with fever, fatigue, malaise, and pallor followed by hemoptysis and severe anemia. Diffuse alveolar hemorrhage was revealed on fiberoptic bronchoscopy. Renal findings consisted of microscopic hematuria, moderate proteinuria, and anti-GBM disease on renal biopsy. ANCA with anti-MPO specificity were present whereas anti-GBM antibodies were on borderline for positivity. Methyl-prednisolone pulses followed by prednisone led to cessation of hemoptysis, marked improvement of lung fuction, and normal finding on chest x-ray within 10 days. An immunosuppressive regimen was then given consisting of prednisone daily for 4 weeks with subsequent taper on alternate day, i.v. cyclophosphamide pulses monthly for 6 doses, followed by mycophenolate mofetil that resulted in normal lung function tests, hemoglobin concentration, and anti-MPO level within four subsequent weeks. During 10-months of follow-up she remained well, her blood pressure and renal function tests were normal, and proteinuria and hematuria gradually resolved. We report a child with an exceptionally rare coexistence of circulating ANCA and anti-GBM disease manifesting as PRS in whom renal disease was not the prominent part of clinical presentation, contrary to other reported pediatric patients. A review of literature on disease with double positive antibodies is

  17. RNAi functionalized collagen-chitosan/silicone membrane bilayer dermal equivalent for full-thickness skin regeneration with inhibited scarring.

    Science.gov (United States)

    Liu, Xing; Ma, Lie; Liang, Jun; Zhang, Bing; Teng, Jianying; Gao, Changyou

    2013-03-01

    Scar inhibition of dermal equivalent is one of the key issues for treatment of full thickness skin defects. To yield a bioactive RNAi functionalized matrix for skin regeneration with inhibited scarring, collagen-chitosan/silicone membrane bilayer dermal equivalent (BDE) was combined with trimetylchitosan (TMC)/siRNA complexes which could induce suppression of transforming growth factor-β1 (TGF-β1) pathway. The RNAi-BDE functioned as a reservoir for the incorporated TMC/siRNA complexes, enabling a prolonged siRNA release. The seeded fibroblasts in the RNAi-BDE showed good viability, internalized the TMC/siRNA complexes effectively and suppressed TGF-β1 expression constantly until 14 d. Application of the RNAi-BDE on the full-thickness skin defects of pig backs confirmed the in vivo inhibition of TGF-β1 expression by immunohistochemistry, real-time quantitative PCR and western blotting during 30 d post surgery. The levels of other scar-related factors such as collagen type I, collagen type III and α-smooth muscle actin (α-SMA) were also down-regulated. In combination with the ultra-thin skin graft transplantation for 73 d, the regenerated skin by RNAi-BDE had an extremely similar structure to that of the normal one. Our study reflects the latest paradigm of tissue engineering by incorporating the emerging biomolecule siRNA. The 3-D scaffolding materials for siRNA delivery may have general implications in generation of bioactive matrix as well. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. The Collagen Family

    Science.gov (United States)

    Ricard-Blum, Sylvie

    2011-01-01

    Collagens are the most abundant proteins in mammals. The collagen family comprises 28 members that contain at least one triple-helical domain. Collagens are deposited in the extracellular matrix where most of them form supramolecular assemblies. Four collagens are type II membrane proteins that also exist in a soluble form released from the cell surface by shedding. Collagens play structural roles and contribute to mechanical properties, organization, and shape of tissues. They interact with cells via several receptor families and regulate their proliferation, migration, and differentiation. Some collagens have a restricted tissue distribution and hence specific biological functions. PMID:21421911

  19. A novel approach revealing the effect of a collagenous membrane on osteoconduction in maxillary sinus floor elevation with β-tricalcium phosphate

    Directory of Open Access Journals (Sweden)

    EAJM Schulten

    2013-03-01

    Full Text Available Calcium phosphates are used in maxillary sinus floor elevation (MSFE procedures to increase bone height prior to dental implant placement. Whether a collagenous barrier membrane coverage of the lateral window affects bone formation within a bone substitute augmentation is currently an important matter of debate, since its benefit has not been irrefutably proven. Therefore, in this clinical study twelve patients underwent an MSFE procedure with β-tricalcium phosphate (β-TCP. The lateral window was either left uncovered, or covered with a resorbable collagenous barrier membrane. After a 6-months healing period, bone biopsies were retrieved during implant placement. Consecutive 1 mm regions of interest of these biopsies were assessed for bone formation, resorption parameters, as well as bone architecture using histology, histomorphometry and micro-computed tomography. Comparable outcomes between the groups with and without membrane were observed regarding osteoconduction rate, bone and graft volume, osteoclast number and structural parameters of newly formed bone per region of interest. However, osteoid volume in grafted maxillary sinus floors without membrane was significantly higher than with membrane. In conclusion, our results – obtained with a novel method employed using 1 mm regions of interest – demonstrate that the clinical application of a bioresorbable collagenous barrier membrane covering the lateral window, after an MSFE procedure with β-TCP, was not beneficial for bone regeneration and even decreased osteoid production which might lead to diminished bone formation in the long run.

  20. Maxillary sinus augmentation: collagen membrane over the osteotomy window. A pilot study

    Directory of Open Access Journals (Sweden)

    F.S. Marchionni

    2015-03-01

    Full Text Available Aim Implant rehabilitation has become a very reliable and safe procedure. However, in some cases, a small amount of bone could make implant surgery extremely difficult or even impossible. Hence, a surgical technique to augment sinus floor has been developed and improved. Nevertheless, there is still controversy over the use of a membrane over the osteotomy window. Therefore, the aim of this study was to investigate whether the use of a membrane could be beneficial in sinus floor augmentation. Materials and methods A group of 12 patients requiring sinus floor lift were recruited. The patients were randomly allocated to either control group (membrane or test group (no membrane and only one sinus for patient was augmented. After 6 months, a bone biopsy was harvested from the lateral window to be processed for histological analysis. Results The mean amount of newly formed bone in test group was 28.0±19.5%, the connective tissue accounted for a mean value of 59.2±15.6%, while 12.8±12.6% was the amount of residual graft particles. In the membrane group the newly formed bone counted for a mean value of 30.4±15.8%, the mean quantity of connective tissue was 50.3±18.9% and about residual graft particles a mean value of 18.2±20.4% was registered. Conclusion According to our data, the use of a membrane over the lateral bone wall in sinus lift surgery does not significantly influence healing. However, the membrane could influence the residual particles resorption rate as well as soft tissue ingrowth.

  1. Collagen-IV and laminin-1 regulate estrogen receptor alpha expression and function in mouse mammary epithelial cells.

    Science.gov (United States)

    Novaro, Virginia; Roskelley, Calvin D; Bissell, Mina J

    2003-07-15

    The expression level and functional activity of estrogen receptor alpha is an important determinant of breast physiology and breast cancer treatment. However, it has been difficult to identify the signals that regulate estrogen receptor because cultured mammary epithelial cells generally do not respond to estrogenic signals. Here, we use a combination of two- and three-dimensional culture systems to dissect the extracellular signals that control endogenous estrogen receptor alpha. Its expression was greatly reduced when primary mammary epithelial cells were placed on tissue culture plastic; however, the presence of a reconstituted basement membrane in combination with lactogenic hormones partially prevented this decrease. Estrogen receptor alpha expression in primary mammary fibroblasts was not altered by these culture conditions, indicating that its regulation is cell type specific. Moreover, estrogen receptor-dependent reporter gene expression, as well as estrogen receptor alpha levels, were increased threefold in a functionally normal mammary epithelial cell line when reconstituted basement membrane was added to the medium. This regulatory effect of reconstituted basement membrane was reproduced by two of its components, collagen-IV and laminin-1, and it was blocked by antibodies against alpha2, alpha6 and beta1 integrin subunits. Our results indicate that integrin-mediated response to specific basement membrane components, rather than cell rounding or cell growth arrest induced by reconstituted basement membrane, is critical in the regulation of estrogen receptor alpha expression and function in mammary epithelial cells.

  2. Collagen-IV and laminin-1 regulate estrogen receptor α expression and function in mouse mammary epithelial cells

    Science.gov (United States)

    Novaro, Virginia; Roskelley, Calvin D.; Bissell, Mina J.

    2010-01-01

    Summary The expression level and functional activity of estrogen receptor α is an important determinant of breast physiology and breast cancer treatment. However, it has been difficult to identify the signals that regulate estrogen receptor because cultured mammary epithelial cells generally do not respond to estrogenic signals. Here, we use a combination of two- and three-dimensional culture systems to dissect the extracellular signals that control endogenous estrogen receptor α. Its expression was greatly reduced when primary mammary epithelial cells were placed on tissue culture plastic; however, the presence of a reconstituted basement membrane in combination with lactogenic hormones partially prevented this decrease. Estrogen receptor α expression in primary mammary fibroblasts was not altered by these culture conditions, indicating that its regulation is cell type specific. Moreover, estrogen receptor-dependent reporter gene expression, as well as estrogen receptor α levels, were increased threefold in a functionally normal mammary epithelial cell line when reconstituted basement membrane was added to the medium. This regulatory effect of reconstituted basement membrane was reproduced by two of its components, collagen-IV and laminin-1, and it was blocked by antibodies against α2, α6 and β1 integrin subunits. Our results indicate that integrin-mediated response to specific basement membrane components, rather than cell rounding or cell growth arrest induced by reconstituted basement membrane, is critical in the regulation of estrogen receptor α expression and function in mammary epithelial cells. PMID:12808020

  3. Rapid Upregulation of Orai1 Abundance in the Plasma Membrane of Platelets Following Activation with Thrombin and Collagen Related Peptide

    Directory of Open Access Journals (Sweden)

    Guilai Liu

    2015-11-01

    Full Text Available Background: Blood platelets accomplish primary hemostasis following vascular injury and contribute to the orchestration of occlusive vascular disease. Platelets are activated by an increase of cytosolic Ca2+-activity ([Ca2+]i, which is accomplished by Ca2+-release from intracellular stores and subsequent store operated Ca2+ entry (SOCE through Ca2+ release activated Ca2+ channel moiety Orai1. Powerful activators of platelets include thrombin and collagen related peptide (CRP, which are in part effective by activation of small G- protein Rac1. The present study explored the influence of thrombin and CRP on Orai1 protein abundance and cytosolic Ca2+-activity ([Ca2+]i in platelets drawn from wild type mice. Methods: Orai1 protein surface abundance was quantified utilizing CF™488A conjugated antibodies, and [Ca2+]i was determined with Fluo3-fluorescence. Results: In resting platelets, Orai1 protein abundance and [Ca2+]i were low. Thrombin (0.02 U/ml and CRP (5ug/ml within 2 min increased [Ca2+]i and Orai1 protein abundance at the platelet surface. [Ca2+]i was further increased by Ca2+ ionophore ionomycin (1 µM and by store depletion with the sarcoendoplasmatic Ca2+ ATPase inhibitor thapsigargin (1 µM. However, Orai1 protein abundance at the platelet surface was not significantly affected by ionomycin and only slightly increased by thapsigargin. The effect of thrombin and CRP on Orai1 abundance and [Ca2+]i was significantly blunted by Rac1 inhibitor NSC23766 (50 µM. Conclusion: The increase of [Ca2+]i following stimulation of platelets with thrombin and collagen related peptide is potentiated by ultrarapid Rac1 sensitive translocation of Orai1 into the cell membrane.

  4. Estimation of the use of fibrin and collagen membranes as carriers for platelet-derived growth factor-BB (PDGF-BB) in the presence of amoxicillin.

    Science.gov (United States)

    Michalska, Marta; Kozakiewicz, Marcin; Bodek, Andrzej; Bodek, Kazimiera Henryka

    2015-04-01

    The effect of homogeneous fibrin (Fb), collagen (Coll) and composite fibrin-heparin (Fb-Hp), fibrin-collagen (Fb-Coll) membranes on in vitro release of platelet-derived growth factor (PDGF-BB) was evaluated in the presence or absence of amoxicillin using of the ELISA immunoassay test. Amoxicillin concentration was determined spectrophotometrically at 272 nm. The process of the PDGF-BB growth factor and amoxicillin release from the studied membranes was of a two-phase nature in the majority of the systems analysed. The PDGF-BB was released in the highest amount from the Coll membrane (M7) without the presence of amoxicillin--546.2 ± 7.47 pg, t0.5 = 0.88 h and 202.5 ± 6.83 pg, t0.5 = 26.65 h during the first phase and second phase, respectively. The lowest PDGF-BB release was observed from composite M4 (Fb-Hp) membrane--5.88 ± 0.81 pg, t0.5 = 1.69 h; and 110.2 ± 6.48 pg, t0.5 = 855.6 h during first and second phase respectively. An optimal release of amoxicillin was observed in the case of the composite M6 (Fb-Coll) membrane--only in the second phase: 64.2 ± 7.8 μg, t0.5 = 83.5 h. The lowest and delayed amoxicillin release was achieved for M4 membrane (approx. 17.1 ± 1.12 μg, t0.5 = 46.5 h). The results of the PDGF-BB release and amoxicillin from membranes indicated a correlation between the level of release and composition of the film. Our results suggested that fibrin and collagen membranes may be beneficial to enhance periodontal bone regeneration.

  5. Morphometric Changes of the Socket after Site Preservation Using Nanobone and Collagen Membrane or Stypro Versus Extraction Alone

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    Salahi S

    2015-06-01

    Full Text Available Statement of Problem: The long-term success of a dental implant relies on implant osseointegration into native and viable bone, implant placement in an ideal position, and optimal hard and soft tissue contour. This requires the presence of sufficient alveolar bone volume, good alveolar ridge (Practically with no sign of atrophy and good surgical technique. Objectives: The aim of this randomized controlled clinical study was to evaluate morphometric changes after different alveolar ridge preservation procedures. Materials and Methods: In this study, 33 patients who had single-rooted premolar, which needed to be extracted, were recruited. Patients were randomly divided into 3 groups and after tooth extraction the following treatments were administered: in group A: NanoBone and a collagen membrane; in group B: NanoBone and Stypro; and in group C: natural healing. The following clinical parameters were evaluated at baseline and 6 months after the extraction: buccolingual width, midbuccal height (with the use of a custom made stent and width of keratinized gingiva. For data analysis, Paired t-test,one-way ANOVA and Tukey’s tests were used. Results: The average reduction in the buccolingual width, midbuccal height and keratinized gingiva was as follows: group A: 1.18±0.6, 0.64±0.92 and 3.45±1.75 mm; group B: 2.18±0.75, 0.73±0.78 and 4.73±0.9 mm; and group C: 1±0.89, 2.36±1.21 and 5±0.63 mm, respectively. Moreover, a significantly reduced resorption was found in both the buccolingual width and the width of keratinized gingiva in group A as compared to groups B and C (p<0.05. Conclusions: This study showed that the use of collagen membrane+Nano bone (group A can significantly reduce the horizontal resorption of the alveolar ridge and keratinized tissue more effectively than stypro+Nano bone (group B and blood clot alone and natural healing (group C.

  6. Development of a human corneal epithelium model utilizing a collagen vitrigel membrane and the changes of its barrier function induced by exposing eye irritant chemicals.

    Science.gov (United States)

    Takezawa, Toshiaki; Nishikawa, Kazunori; Wang, Pi-Chao

    2011-09-01

    The brief TEER (trans-epithelial electrical resistance) assay after exposing chemicals to corneal epithelium in vivo is known as a suitable method for evaluating corneal irritancy and permeability quantitatively and continuously. A collagen vitrigel membrane we previously developed is a thin (about 20 μm thick) and transparent membrane composed of high density collagen fibrils equivalent to connective tissues in vivo, e.g. corneal Bowman's membrane. To develop such a TEER assay system in vitro utilizing a human corneal epithelial model, HCE-T cells (a human corneal epithelial cell line) were cultured on the collagen vitrigel membrane substratum prepared in a Millicell chamber suitable for TEER measurement. Human corneal epithelium model possessing 5-6 cell layers sufficient for TEER assay was successfully reconstructed on the substratum in the Millicell chamber by culturing the cells in monolayer for 2 days and subsequently in air-liquid interface for 7 days. The exposure of chemicals to the model induced the time-dependent relative changes of TEER in response to the characteristic of each chemical within a few minutes. These results suggest that the TEER assay using the human corneal epithelial model is very useful for an ocular irritancy evaluation as an alternative to the Draize eye irritation test. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Type IV collagen drives alveolar epithelial-endothelial association and the morphogenetic movements of septation.

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    Loscertales, Maria; Nicolaou, Fotini; Jeanne, Marion; Longoni, Mauro; Gould, Douglas B; Sun, Yunwei; Maalouf, Faouzi I; Nagy, Nandor; Donahoe, Patricia K

    2016-07-13

    Type IV collagen is the main component of the basement membrane that gives strength to the blood-gas barrier (BGB). In mammals, the formation of a mature BGB occurs primarily after birth during alveologenesis and requires the formation of septa from the walls of the saccule. In contrast, in avians, the formation of the BGB occurs rapidly and prior to hatching. Mutation in basement membrane components results in an abnormal alveolar phenotype; however, the specific role of type IV collagen in regulating alveologenesis remains unknown. We have performed a microarray expression analysis in late chick lung development and found that COL4A1 and COL4A2 were among the most significantly upregulated genes during the formation of the avian BGB. Using mouse models, we discovered that mutations in murine Col4a1 and Col4a2 genes affected the balance between lung epithelial progenitors and differentiated cells. Mutations in Col4a1 derived from the vascular component were sufficient to cause defects in vascular development and the BGB. We also show that Col4a1 and Col4a2 mutants displayed disrupted myofibroblast proliferation, differentiation and migration. Lastly, we revealed that addition of type IV collagen protein induced myofibroblast proliferation and migration in monolayer culture and increased the formation of mesenchymal-epithelial septal-like structures in co-culture. Our study showed that type IV collagen and, therefore the basement membrane, play fundamental roles in coordinating alveolar morphogenesis. In addition to its role in the formation of epithelium and vasculature, type IV collagen appears to be key for alveolar myofibroblast development by inducing their proliferation, differentiation and migration throughout the developing septum.

  8. Matrix-Induced Autologous Chondrocyte Implantation (MACI) Using a Cell-Seeded Collagen Membrane Improves Cartilage Healing in the Equine Model.

    Science.gov (United States)

    Nixon, Alan J; Sparks, Holly D; Begum, Laila; McDonough, Sean; Scimeca, Michael S; Moran, Nance; Matthews, Gloria L

    2017-12-06

    Autologous chondrocyte implantation (ACI) using a collagen scaffold (matrix-induced ACI; MACI) is a next-generation approach to traditional ACI that provides the benefit of autologous cells and guided tissue regeneration using a biocompatible collagen scaffold. The MACI implant also has inherent advantages including surgical implantation via arthroscopy or miniarthrotomy, the elimination of periosteal harvest, and the use of tissue adhesive in lieu of sutures. This study evaluated the efficacy of the MACI implant in an equine full-thickness cartilage defect model at 1 year. Autologous chondrocytes were seeded onto a collagen type-I/III membrane and implanted into one of two 15-mm defects in the femoral trochlear ridge of 24 horses. Control defects either were implanted with cell-free collagen type-I/III membrane (12 horses) or were left ungrafted as empty defects (12 horses). An additional 3 horses had both 15-mm defects remain empty as nonimplanted joints. The repair was scored by second-look arthroscopy (12 weeks), and necropsy examination (53 weeks). Healing was assessed by arthroscopic scoring, gross assessment, histology and immunohistology, cartilage matrix component assay, and gene expression determination. Toxicity was examined by prostaglandin E2 formation in joint fluid, and lymph node morphology combined with histologic screening of organs. MACI-implanted defects had improved gross healing and composite histologic scores, as well as increases in chondrocyte predominance, toluidine blue-stained matrix, and collagen type-II content compared with scaffold-only implanted or empty defects. There was minimal evidence of reaction to the implant in the synovial membrane (minor perivascular cuffing), subchondral bone, or cartilage. There were no adverse clinical effects, signs of organ toxicity, or evidence of chondrocytes or collagen type-I/III membrane in draining lymph nodes. The MACI implant appeared to improve cartilage healing in a critical-sized defect in

  9. Enhancement of tendon–bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt

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    Chou YC

    2016-08-01

    Full Text Available Ying-Chao Chou,1,2 Wen-Lin Yeh,2 Chien-Lin Chao,1 Yung-Heng Hsu,1,2 Yi-Hsun Yu,1,2 Jan-Kan Chen,3 Shih-Jung Liu1,2 1Department of Mechanical Engineering, Chang Gung University, 2Department of Orthopedic Surgery, Chang Gung Memorial Hospital, 3Department of Physiology and Pharmacology, Chang Gung University, Taoyuan, Taiwan Abstract: A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA bolt as the bone anchor and a poly(D,L-lactide-co-glycolide (PLGA nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon–bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon–bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon–bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon–bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. Keywords: polylactide–polyglycolide nanofibers, PLGA, collagen, 3D printing, polylactide, PLA, bone-anchoring bolts, tendon healing

  10. Clinical and radiographical evaluation of a bioresorbable collagen membrane of fish origin in the treatment of periodontal intrabony defects: A preliminary study

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    B B Santosh Kumar

    2013-01-01

    Full Text Available Background: Recently, there has been interest in non-mammalian collagen sources such as fish collagen in periodontal regeneration. In the present study, collagen barrier membrane of fish origin was assessed in the treatment of periodontal intrabony defects. Materials and Methods: Ten systemically healthy chronic periodontitis patients having a paired osseous defect in the mandibular posterior teeth were selected and randomly assigned to receive a collagen membrane (test or open flap debridement (control in a split mouth design. Clinical parameters such as Plaque index, Gingival bleeding index, Probing pocket depth, Relative attachment level, and Recession were recorded at baseline, 3, 6, and at 9 months, while radiographic evaluation was done to assess alveolar crestal bone level and percentage of defect fill at 6 and 9 months using autoCAD 2007 software. Student′s t test (two-tailed, dependent was used to find the significance of study parameters on continuous scale. Significance was set at 5% level of significance. Wilcoxon signed rank test was used to find the significance of percentage change of defect fill. Results: The comparison between the two groups did not show any statistically significant differences in the parameters assessed (P > 0.05 but, within each group, clinical parameters showed statistically significant differences from baseline to 9 months (P < 0.05. Conclusion: Within the limits of the study, it can be inferred that no significant differences were found either by using collagen membrane of fish origin or open flap debridement in the treatment of periodontal intrabony defects.

  11. Clinical and Radiographic Assessment of the Efficacy of a Collagen Membrane in Regenerative Endodontics: A Randomized, Controlled Clinical Trial.

    Science.gov (United States)

    Jiang, Xijun; Liu, He; Peng, Chufang

    2017-09-01

    Recent reviews confirm a general lack of randomized, controlled clinical studies on the efficacy of regenerative endodontics in immature teeth affected by pulp and periapical diseases. Moreover, we have no evidence of the curative efficacy of collagen membranes used as scaffolds in regenerative endodontics. Here, we evaluated whether a Bio-Gide collagen membrane (Geistlich Pharma AG, Wolhusen, Switzerland) has efficacy in promoting dentin formation in regenerative endodontics. Forty-three patients yielding a total of 46 nonvital immature teeth were divided randomly into 2 groups. Subsequent to chemomechanical preparation, regenerative endodontics with (the experimental group) and without (the control group) Bio-Gide were performed. All cases were followed up clinically and radiographically every 3 months for at least 6 months. Quantitative analyses using an imaging program yielded percentage changes in root dimensions based on a comparison between preoperative and recall radiographs. The results of 40 patients (43 teeth) were included in the final analyses. All patients from both groups showed clinical success with complete resolution of signs and symptoms. Radiographically, the thickness of the dentin wall at the middle third of the root was higher for the experimental group than the control group. However, other indicators were comparable between both groups. The use of the Bio-Gide collagen membrane promoted the development of the dentin wall in the middle third of the root in patients undergoing regenerative endodontic procedures. The convenience of operation and the assured positioning of the sealing material make the Bio-Gide collagen membrane especially suitable for handling wide root canals. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  12. Collagenous gastritis.

    Science.gov (United States)

    Jin, Xiaoyi; Koike, Tomoyuki; Chiba, Takashi; Kondo, Yutaka; Ara, Nobuyuki; Uno, Kaname; Asano, Naoki; Iijima, Katsunori; Imatani, Akira; Watanabe, Mika; Shirane, Akio; Shimosegawa, Tooru

    2013-09-01

    In the present paper, we report a case of rare collagenous gastritis. The patient was a 25-year-old man who had experienced nausea, abdominal distention and epigastralgia since 2005. Esophagogastroduodenoscopy (EGD) carried out at initial examination by the patient's local doctor revealed an extensively discolored depression from the upper gastric body to the lower gastric body, mainly including the greater curvature, accompanied by residual mucosa with multiple islands and nodularity with a cobblestone appearance. Initial biopsies sampled from the nodules and accompanying atrophic mucosa were diagnosed as chronic gastritis. In August, 2011, the patient was referred to Tohoku University Hospital for observation and treatment. EGD at our hospital showed the same findings as those by the patient's local doctor. Pathological findings included a membranous collagen band in the superficial layer area of the gastric mucosa, which led to a diagnosis of collagenous gastritis. Collagenous gastritis is an extremely rare disease, but it is important to recognize its characteristic endoscopic findings to make a diagnosis. © 2012 The Authors. Digestive Endoscopy © 2012 Japan Gastroenterological Endoscopy Society.

  13. Biology of Hsp47 (Serpin H1), a collagen-specific molecular chaperone.

    Science.gov (United States)

    Ito, Shinya; Nagata, Kazuhiro

    2017-02-01

    Hsp47, a collagen-specific molecular chaperone that localizes in the endoplasmic reticulum (ER), is indispensable for molecular maturation of collagen. Hsp47, which is encoded by the SERPINH1 gene, belongs to the serpin family and has the serpin fold; however, it has no serine protease inhibitory activity. Hsp47 transiently binds to procollagen in the ER, dissociates in the cis-Golgi or ER-Golgi intermediate compartment (ERGIC) in a pH-dependent manner, and is then transported back to the ER via its RDEL retention sequence. Hsp47 recognizes collagenous (Gly-Xaa-Arg) repeats on triple-helical procollagen and can prevent local unfolding and/or aggregate formation of procollagen. Gene disruption of Hsp47 in mice causes embryonic lethality due to impairments in basement membrane and collagen fibril formation. In Hsp47-knockout cells, the type I collagen triple helix forms abnormally, resulting in thin and frequently branched fibrils. Secretion of type I collagens is slow and plausible in making aggregates of procollagens in the ER of hsp47-knocked out fibroblasts, which are ultimately degraded by autophagy. Mutations in Hsp47 are causally associated with osteogenesis imperfecta. Expression of Hsp47 is strongly correlated with expression of collagens in multiple types of cells and tissues. Therefore, Hsp47 represents a promising target for treatment of collagen-related disorders, including fibrosis of the liver, lung, and other organs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Alveolar ridge preservation with an open-healing approach using single-layer or double-layer coverage with collagen membranes.

    Science.gov (United States)

    Choi, Ho-Keun; Cho, Hag-Yeon; Lee, Sung-Jo; Cho, In-Woo; Shin, Hyun-Seung; Koo, Ki-Tae; Lim, Hyun-Chang; Park, Jung-Chul

    2017-12-01

    The aim of this prospective pilot study was to compare alveolar ridge preservation (ARP) procedures with open-healing approach using a single-layer and a double-layer coverage with collagen membranes using radiographic and clinical analyses. Eleven molars from 9 healthy patients requiring extraction of the maxillary or mandibular posterior teeth were included and allocated into 2 groups. After tooth extraction, deproteinized bovine bone mineral mixed with 10% collagen was grafted into the socket and covered either with a double-layer of resorbable non-cross-linked collagen membranes (DL group, n=6) or with a single-layer (SL group, n=5). Primary closure was not obtained. Cone-beam computed tomography images were taken immediately after the ARP procedure and after a healing period of 4 months before implant placement. Radiographic measurements were made of the width and height changes of the alveolar ridge. All sites healed without any complications, and dental implants were placed at all operated sites with acceptable initial stability. The measurements showed that the reductions in width at the level 1 mm apical from the alveolar crest (including the bone graft) were -1.7±0.5 mm in the SL group and -1.8±0.4 mm in the DL group, and the horizontal changes in the other areas were also similar in the DL and SL groups. The reductions in height were also comparable between groups. Within the limitations of this study, single-layer and double-layer coverage with collagen membranes after ARP failed to show substantial differences in the preservation of horizontal or vertical dimensions or in clinical healing. Thus, both approaches seem to be suitable for open-healing ridge preservation procedures.

  15. Influence of basement membrane proteins and endothelial cell-derived factors on the morphology of human fetal-derived astrocytes in 2D.

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    Amanda F Levy

    Full Text Available Astrocytes are the most prevalent type of glial cell in the brain, participating in a variety of diverse functions from regulating cerebral blood flow to controlling synapse formation. Astrocytes and astrocyte-conditioned media are widely used in models of the blood-brain barrier (BBB, however, very little is known about astrocyte culture in 2D. To test the hypothesis that surface coating and soluble factors influence astrocyte morphology in 2D, we quantitatively analyzed the morphology of human fetal derived astrocytes on glass, matrigel, fibronectin, collagen IV, and collagen I, and after the addition soluble factors including platelet-derived growth factor (PDGF, laminin, basic fibroblast growth factor (bFGF, and leukemia inhibitory factor (LIF. Matrigel surface coatings, as well as addition of leukemia inhibitory factor (LIF to the media, were found to have the strongest effects on 2D astrocyte morphology, and may be important in improving existing BBB models. In addition, the novel set of quantitative parameters proposed in this paper provide a test for determining the influence of compounds on astrocyte morphology, both to screen for new endothelial cell-secreted factors that influence astrocytes, and to determine in a high-throughput way which factors are important for translation to more complex, 3D BBB models.

  16. Guided Bone Regeneration With or Without a Collagen Membrane in Rats with Induced Diabetes Mellitus: Histomorphometric and Immunolocalization Analysis of Angiogenesis and Bone Turnover Markers.

    Science.gov (United States)

    Jardini, Maria Aparecida; Tera, Tábata Mello; Meyer, Augusto Andrade; Moretto, Camilla Magnoni; Prado, Renata Falchete; Santamaria, Mauro Pedrine

    2016-01-01

    Diabetes mellitus (DM) affects the processes of repair, wound healing, and bone remodeling. This study was conducted to evaluate autologous bone graft integration, either with or without guided bone regeneration, through analyzing the expression of bone reabsorption markers and neovascularization in rats suffering from DM. Thirty adult Wistar rats were divided into two groups: The DM group received an injection of alloxan monohydrate (150 mg/kg), and the control group received an injection of sterile saline. Fifteen days afterward, an autologous bone grafting was performed in each of their arches, with the insertion of a membrane into the left arch. Euthanasia occurred in 7, 21, or 60 days after the surgery. Bone samples were processed for histomorphometric and immunohistochemical analyses. After a statistical analysis of the data, the presence of DM did not interfere negatively in the bone autograft repair. The collagen membrane favored the graft integration into the recipient bed and the bone neoformation around the graft. Greater vascularization was observed between 21 and 60 days after the surgery, which increased bone formation and resulted in the graft integration. Only the RANK marker showed a significant difference in the glycemic groups. Transglutaminase 2 was significant for the membrane presence and experimental time. It is hence concluded that diabetes mellitus does not interfere with bone reabsorption via the RANK/RANKL/OPG. The graft integration was similar between the groups; however, the results of hyperglycemia with the collagen membrane indicate greater bone growth after graft placement.

  17. Matrix metalloproteinase-2 and its correlation with basal membrane components laminin-5 and collagen type IV in paediatric burn patients measured with Surface Plasmon Resonance Imaging (SPRI) biosensors.

    Science.gov (United States)

    Weremijewicz, Artur; Matuszczak, Ewa; Sankiewicz, Anna; Tylicka, Marzena; Komarowska, Marta; Tokarzewicz, Anna; Debek, Wojciech; Gorodkiewicz, Ewa; Hermanowicz, Adam

    2018-01-30

    The purpose of this study was the determination of matrix metalloproteinase-2 and its correlation with basal membrane components laminin-5 and collagen type IV in the blood plasma of burn patients measured with Surface Plasmon Resonance Imaging (SPRI) biosensors. 31 children scalded by hot water who were managed at the Department of Paediatric Surgery between 2014-2015, after primarily presenting with burns in 4-20% TBSA were included into the study (age 9 months up to 14 years, mean age 2,5+1 years). There were 10 girls and 21 boys. Venous blood samples were drawn 2-6h, and 12-16h after the thermal injury, and on the subsequent days 3, 5 and 7. The matrix metalloproteinase-2, collagen type IV and laminin-5 concentrations were assessed using Surface Plasmon Resonance Imaging by the investigators blinded to the other data. The MMP-2, laminin-5 and collagen type IV concentrations in the blood plasma of patients with burns, were highest 12-16h after thermal injury, the difference was statistically significant. The MMP-2, laminin-5 and collagen type IV concentrations measured 3 days, 5 days and 7 days after the thermal injury, slowly decreased over time, and on the 7th day reached the normal range, when compared with the concentration measured in controls. Current work is the first follow-up study regarding MMP-2 in burns. MMP-2, laminin-5 and collagen type IV levels were elevated early after burn injury in the plasma of studied patients, and were highest 12-16h after the injury. MMP-2, laminin-5 and collagen type IV levels were not proportional to the severity of the burn. We believe in the possibility that the gradual decrease of MMP-2, collagen type IV and laminin-5 concentrations could be connected with the process of healing, but to prove it, more investigation is needed in this area. The SPR imaging biosensor is a good diagnostic tool for determination of MMP-2, laminin-5 and collagen type IV in blood plasma of patients with burns. Copyright © 2017 Elsevier Ltd

  18. In vitro cultivation of canine multipotent mesenchymal stromal cells on collagen membranes treated with hyaluronic acid for cell therapy and tissue regeneration

    International Nuclear Information System (INIS)

    Wodewotzky, T.I.; Lima-Neto, J.F.; Pereira-Júnior, O.C.M.; Sudano, M.J.; Lima, S.A.F.; Bersano, P.R.O.; Yoshioka, S.A.; Landim-Alvarenga, F.C.

    2012-01-01

    Support structures for dermal regeneration are composed of biodegradable and bioresorbable polymers, animal skin or tendons, or are bacteria products. The use of such materials is controversial due to their low efficiency. An important area within tissue engineering is the application of multipotent mesenchymal stromal cells (MSCs) to reparative surgery. The combined use of biodegradable membranes with stem cell therapy may lead to promising results for patients undergoing unsuccessful conventional treatments. Thus, the aim of this study was to test the efficacy of using membranes composed of anionic collagen with or without the addition of hyaluronic acid (HA) as a substrate for adhesion and in vitro differentiation of bone marrow-derived canine MSCs. The benefit of basic fibroblast growth factor (bFGF) on the differentiation of cells in culture was also tested. MSCs were collected from dog bone marrow, isolated and grown on collagen scaffolds with or without HA. Cell viability, proliferation rate, and cellular toxicity were analyzed after 7 days. The cultured cells showed uniform growth and morphological characteristics of undifferentiated MSCs, which demonstrated that MSCs successfully adapted to the culture conditions established by collagen scaffolds with or without HA. This demonstrates that such scaffolds are promising for applications to tissue regeneration. bFGF significantly increased the proliferative rate of MSCs by 63% when compared to groups without the addition of the growth factor. However, the addition of bFGF becomes limiting, since it has an inhibitory effect at high concentrations in culture medium

  19. In vitro cultivation of canine multipotent mesenchymal stromal cells on collagen membranes treated with hyaluronic acid for cell therapy and tissue regeneration

    Directory of Open Access Journals (Sweden)

    T.I. Wodewotzky

    2012-12-01

    Full Text Available Support structures for dermal regeneration are composed of biodegradable and bioresorbable polymers, animal skin or tendons, or are bacteria products. The use of such materials is controversial due to their low efficiency. An important area within tissue engineering is the application of multipotent mesenchymal stromal cells (MSCs to reparative surgery. The combined use of biodegradable membranes with stem cell therapy may lead to promising results for patients undergoing unsuccessful conventional treatments. Thus, the aim of this study was to test the efficacy of using membranes composed of anionic collagen with or without the addition of hyaluronic acid (HA as a substrate for adhesion and in vitro differentiation of bone marrow-derived canine MSCs. The benefit of basic fibroblast growth factor (bFGF on the differentiation of cells in culture was also tested. MSCs were collected from dog bone marrow, isolated and grown on collagen scaffolds with or without HA. Cell viability, proliferation rate, and cellular toxicity were analyzed after 7 days. The cultured cells showed uniform growth and morphological characteristics of undifferentiated MSCs, which demonstrated that MSCs successfully adapted to the culture conditions established by collagen scaffolds with or without HA. This demonstrates that such scaffolds are promising for applications to tissue regeneration. bFGF significantly increased the proliferative rate of MSCs by 63% when compared to groups without the addition of the growth factor. However, the addition of bFGF becomes limiting, since it has an inhibitory effect at high concentrations in culture medium.

  20. In vitro cultivation of canine multipotent mesenchymal stromal cells on collagen membranes treated with hyaluronic acid for cell therapy and tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Wodewotzky, T.I.; Lima-Neto, J.F. [Departamento de Reprodução Animal e Radiologia Veterinária, Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual de São Paulo, Botucatu, SP (Brazil); Pereira-Júnior, O.C.M. [Departamento de Reprodução Animal e Radiologia Veterinária, Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual de São Paulo, Botucatu, SP (Brazil); Departamento de Cirurgia e Anestesiologia Veterinária, Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual de São Paulo, Botucatu, SP (Brazil); Sudano, M.J.; Lima, S.A.F. [Departamento de Reprodução Animal e Radiologia Veterinária, Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual de São Paulo, Botucatu, SP (Brazil); Bersano, P.R.O. [Departamento de Patologia Veterinária, Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual de São Paulo, Botucatu, SP (Brazil); Yoshioka, S.A. [Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, SP (Brazil); Landim-Alvarenga, F.C. [Departamento de Reprodução Animal e Radiologia Veterinária, Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual de São Paulo, Botucatu, SP (Brazil)

    2012-09-21

    Support structures for dermal regeneration are composed of biodegradable and bioresorbable polymers, animal skin or tendons, or are bacteria products. The use of such materials is controversial due to their low efficiency. An important area within tissue engineering is the application of multipotent mesenchymal stromal cells (MSCs) to reparative surgery. The combined use of biodegradable membranes with stem cell therapy may lead to promising results for patients undergoing unsuccessful conventional treatments. Thus, the aim of this study was to test the efficacy of using membranes composed of anionic collagen with or without the addition of hyaluronic acid (HA) as a substrate for adhesion and in vitro differentiation of bone marrow-derived canine MSCs. The benefit of basic fibroblast growth factor (bFGF) on the differentiation of cells in culture was also tested. MSCs were collected from dog bone marrow, isolated and grown on collagen scaffolds with or without HA. Cell viability, proliferation rate, and cellular toxicity were analyzed after 7 days. The cultured cells showed uniform growth and morphological characteristics of undifferentiated MSCs, which demonstrated that MSCs successfully adapted to the culture conditions established by collagen scaffolds with or without HA. This demonstrates that such scaffolds are promising for applications to tissue regeneration. bFGF significantly increased the proliferative rate of MSCs by 63% when compared to groups without the addition of the growth factor. However, the addition of bFGF becomes limiting, since it has an inhibitory effect at high concentrations in culture medium.

  1. One-stage horizontal guided bone regeneration with autologous bone, anorganic bovine bone and collagen membranes: Follow-up of a prospective study 30 months after loading.

    Science.gov (United States)

    Meloni, Silvio Mario; Jovanovic, Sascha Alexander; Pisano, Milena; De Riu, Giacomo; Baldoni, Edoardo; Tallarico, Marco

    2018-01-01

    To present the medium-term results of one-stage guided bone regeneration (GBR) using autologous bone and anorganic bovine bone, placed in layers, in association with resorbable collagen membranes, for the reconstruction of horizontal bony defects. This study was designed as an uncontrolled prospective study. Partially edentulous patients, having less than 6.0 mm and more than 4.0 mm of residual horizontal bone width were selected and consecutively treated with simultaneously implant installation and bone regeneration by using 2.0 mm of autologous bone and 2.0 mm of anorganic bovine bone that was placed in layers and then covered with a resorbable collagen membrane. Outcome measures were: implant and prosthesis failures, any complications, peri-implant marginal bone level changes, probing pocket depth (PPD) and bleeding on probing (BOP). In total, 45 consecutive patients (20 male, 25 female) with a mean age of 52.1 years each received at least one GBR procedure, with contemporary placement of 63 implants. At the 3-year follow-up examination, no patient had dropped out and no deviation from the original protocol had occurred. No implant or prosthesis failed. In six patients (13.3%) the collagen membrane was slightly exposed 1 to 2 weeks after bone reconstruction. Four of these patients were moderate smokers. Post-hoc analysis using Fisher's exact test found significant association (P = 0.0139) between a smoking habit and early membrane exposure. Mean marginal bone loss experienced between initial loading and 30 months afterwards was 0.60 ± 0.20 mm (95% CI 0.54 - 0.66). The mean BOP values measured at the definitive restoration delivery were 1.23 ± 0.93, while 2 years later they were 1.17 ± 0.78. The difference was not statistically significant (-0.06 ± 0.76; P = 0.569). The mean PPD values measured at the definitive restoration delivery were 2.62 ± 0.59 mm, while 2 years later they were 2.60 ± 0.54 mm. The difference was not statistically significant (-0.03

  2. Quaternary epitopes of α345(IV) collagen initiate Alport post-transplant anti-GBM nephritis

    DEFF Research Database (Denmark)

    Olaru, Florina; Luo, Wentian; Wang, Xu-Ping

    2013-01-01

    Alport post-transplant nephritis (APTN) is an aggressive form of anti-glomerular basement membrane disease that targets the allograft in transplanted patients with X-linked Alport syndrome. Alloantibodies develop against the NC1 domain of α5(IV) collagen, which occurs in normal kidneys, including...... of alloantibodies against allogeneic collagen IV. Some alloantibodies targeted alloepitopes within α5NC1 monomers, shared by α345NC1 and α1256NC1 hexamers. Other alloantibodies specifically targeted alloepitopes that depended on the quaternary structure of α345NC1 hexamers. In Col4a5-null mice, immunization...... with native forms of allogeneic collagen IV exclusively elicited antibodies to quaternary α345NC1 alloepitopes, whereas alloimmunogens lacking native quaternary structure elicited antibodies to shared α5NC1 alloepitopes. These results imply that quaternary epitopes within α345NC1 hexamers may initiate...

  3. Synthesis and character investigation of new collagen Hydrolysate/polyvinyl alcohol/hydroxyapatite Polymer-Nano-Porous Membranes: I. Experimental design optimization in thermal and structural properties.

    Science.gov (United States)

    Imanieh, Hossein; Aghahosseini, Hamideh

    2013-12-01

    Development of bioorganic-inorganic composites has drawn eyes to extensive attention in biomedical fields and tissue engineering. So many attempts to prepare hydroxyapatite (HA), in conjunction with various binders including polyvinyl alcohol (PVA), and collagen has performed for late 20 years. We applied a method based on the phase separation for making of polymer porous membranes. This procedure is induced through the addition of a small quantity of water (polymer-rich phase) to a solution with HA precursors (polymer-poor phase). Thermal and structural composite properties of collagen Hydrolysate (CH)-PVA/HA Polymer-Nano-Porous Membranes were analyzed by Design of experiment that was undertaken using D-optimal approach, to select the optimal combination of nano composites precursor. The resulted composite characters were investigated by Fourier transform infrared, scanning electron microscopy (SEM) and thermal gravimetric analysis. Based on the SEM images, this new method could be clearly concluded to porous CH-PVA/HA hybrid materials. Finally the hemocompatibility of nanocomposite membranes were evaluated by the hemolysis study.

  4. Comparative evaluation of a bioabsorbable collagen membrane and connective tissue graft in the treatment of localized gingival recession: A clinical study

    Directory of Open Access Journals (Sweden)

    Harsha Mysore Babu

    2011-01-01

    Full Text Available Background: Gingival recession (GR can result in root sensitivity, esthetic concern to the patient, and predilection to root caries. The purpose of this randomized clinical study was to evaluate (1 the effect of guided tissue regeneration (GTR procedure using a bioabsorbable collagen membrane, in comparison to autogenous subepithelial connective tissue graft (SCTG for root coverage in localized gingival recession defects; and (2 the change in width of keratinized gingiva following these two procedures. Materials and Methods: A total of 10 cases, showing at least two localized Miller′s Class I or Class II gingival recession, participated in this study. In a split mouth design, the pairs of defects were randomly assigned for treatment with either SCTG (SCTG Group or GTR-based collagen membrane (GTRC Group. Both the grafts were covered with coronally advanced flap. Recession depth (RD, recession width (RW, width of keratinized gingiva (KG, probing depth (PD, relative attachment level (RAL, plaque index (PI, and gingival index (GI were recorded at baseline, 3 and 6 months postoperatively. Results: Six months following root coverage procedures, the mean root coverage was found to be 84.84% ± 16.81% and 84.0% ± 15.19% in SCTG Group and GTRC Group, respectively. The mean keratinized gingival width increase was 1.50 ± 0.70 mm and 2.30 ± 0.67 mm in the SCTG and GTRC group, respectively, which was not statistically significant. Conclusion: It may be concluded that resorbable collagen membrane can be a reliable alternative to autogenous connective tissue graft in the treatment of gingival recession.

  5. Clinical comparison of guided tissue regeneration, with collagen membrane and bone graft, versus connective tissue graft in the treatment of gingival recessions

    Directory of Open Access Journals (Sweden)

    Haghighati F

    2006-06-01

    Full Text Available Background and Aim: Increasing patient demands for esthetic, put the root coverage procedures in particular attention. Periodontal regeneration with GTR based root coverage methods is the most common treatment used. The purpose of this study was to compare guided tissue regeneration (GTR with collagen membrane and a bone graft, with sub-epithelial connective tissue graft (SCTG, in treatment of gingival recession. Materials and Methods: In this randomized clinical trial study, eleven healthy patients with no systemic diseases who had miller’s class I or II recession defects (gingival recession  2mm were treated with SCTG or GTR using a collagen membrane and a bone graft. Clinical measurements were obtained at baseline and 6 months after surgery. These clinical measurements included recession depth (RD, recession width (RW, probing depth (PD, and clinical attachment level (CAL. Data were analyzed using independent t test with p<0.05 as the limit of significance. Results: Both treatment methods resulted in a statistically significant reduction of recession depth (SCTG=2.3mm, GTR=2.1mm; P<0.0001. CAL gain after 6 months was also improved in both groups (SCG= 2.5mm, GTR=2.1mm, compared to baseline (P<0.0001. No statistical differences were observed in RD, RW, CAL between test and control groups. Root coverage was similar in both methods (SCTG= 74.2%, GTR= 62.6%, P=0.87. Conclusion: Based on the results of this study, the two techniques are clinically comparable. Therefore the use of collagen membrane and a bovine derived xenograft may alleviate the need for connective tissue graft.

  6. Col6a1 Null Mice as a Model to Study Skin Phenotypes in Patients with Collagen VI Related Myopathies: Expression of Classical and Novel Collagen VI Variants during Wound Healing

    Science.gov (United States)

    Lettmann, Sandra; Bloch, Wilhelm; Maaß, Tobias; Niehoff, Anja; Schulz, Jan-Niklas; Eckes, Beate; Eming, Sabine A.; Bonaldo, Paolo; Paulsson, Mats; Wagener, Raimund

    2014-01-01

    Patients suffering from collagen VI related myopathies caused by mutations in COL6A1, COL6A2 and COL6A3 often also display skin abnormalities, like formation of keloids or “cigarette paper” scars, dry skin, striae rubrae and keratosis pilaris (follicular keratosis). Here we evaluated if Col6a1 null mice, an established animal model for the muscle changes in collagen VI related myopathies, are also suitable for the study of mechanisms leading to the skin pathology. We performed a comprehensive study of the expression of all six collagen VI chains in unwounded and challenged skin of wild type and Col6a1 null mice. Expression of collagen VI chains is regulated in both skin wounds and bleomycin-induced fibrosis and the collagen VI α3 chain is proteolytically processed in both wild type and Col6a1 null mice. Interestingly, we detected a decreased tensile strength of the skin and an altered collagen fibril and basement membrane architecture in Col6a1 null mice, the latter being features that are also found in collagen VI myopathy patients. Although Col6a1 null mice do not display an overt wound healing defect, these mice are a relevant animal model to study the skin pathology in collagen VI related disease. PMID:25158062

  7. Col6a1 null mice as a model to study skin phenotypes in patients with collagen VI related myopathies: expression of classical and novel collagen VI variants during wound healing.

    Directory of Open Access Journals (Sweden)

    Sandra Lettmann

    Full Text Available Patients suffering from collagen VI related myopathies caused by mutations in COL6A1, COL6A2 and COL6A3 often also display skin abnormalities, like formation of keloids or "cigarette paper" scars, dry skin, striae rubrae and keratosis pilaris (follicular keratosis. Here we evaluated if Col6a1 null mice, an established animal model for the muscle changes in collagen VI related myopathies, are also suitable for the study of mechanisms leading to the skin pathology. We performed a comprehensive study of the expression of all six collagen VI chains in unwounded and challenged skin of wild type and Col6a1 null mice. Expression of collagen VI chains is regulated in both skin wounds and bleomycin-induced fibrosis and the collagen VI α3 chain is proteolytically processed in both wild type and Col6a1 null mice. Interestingly, we detected a decreased tensile strength of the skin and an altered collagen fibril and basement membrane architecture in Col6a1 null mice, the latter being features that are also found in collagen VI myopathy patients. Although Col6a1 null mice do not display an overt wound healing defect, these mice are a relevant animal model to study the skin pathology in collagen VI related disease.

  8. Collagen XII and XIV, New Partners of Cartilage Oligomeric Matrix Protein in the Skin Extracellular Matrix Suprastructure*

    Science.gov (United States)

    Agarwal, Pallavi; Zwolanek, Daniela; Keene, Douglas R.; Schulz, Jan-Niklas; Blumbach, Katrin; Heinegård, Dick; Zaucke, Frank; Paulsson, Mats; Krieg, Thomas; Koch, Manuel; Eckes, Beate

    2012-01-01

    The tensile and scaffolding properties of skin rely on the complex extracellular matrix (ECM) that surrounds cells, vasculature, nerves, and adnexus structures and supports the epidermis. In the skin, collagen I fibrils are the major structural component of the dermal ECM, decorated by proteoglycans and by fibril-associated collagens with interrupted triple helices such as collagens XII and XIV. Here we show that the cartilage oligomeric matrix protein (COMP), an abundant component of cartilage ECM, is expressed in healthy human skin. COMP expression is detected in the dermal compartment of skin and in cultured fibroblasts, whereas epidermis and HaCaT cells are negative. In addition to binding collagen I, COMP binds to collagens XII and XIV via their C-terminal collagenous domains. All three proteins codistribute in a characteristic narrow zone in the superficial papillary dermis of healthy human skin. Ultrastructural analysis by immunogold labeling confirmed colocalization and further revealed the presence of COMP along with collagens XII and XIV in anchoring plaques. On the basis of these observations, we postulate that COMP functions as an adapter protein in human skin, similar to its function in cartilage ECM, by organizing collagen I fibrils into a suprastructure, mainly in the vicinity of anchoring plaques that stabilize the cohesion between the upper dermis and the basement membrane zone. PMID:22573329

  9. Type XVII collagen coordinates proliferation in the interfollicular epidermis.

    Science.gov (United States)

    Watanabe, Mika; Natsuga, Ken; Nishie, Wataru; Kobayashi, Yasuaki; Donati, Giacomo; Suzuki, Shotaro; Fujimura, Yu; Tsukiyama, Tadasuke; Ujiie, Hideyuki; Shinkuma, Satoru; Nakamura, Hideki; Murakami, Masamoto; Ozaki, Michitaka; Nagayama, Masaharu; Watt, Fiona M; Shimizu, Hiroshi

    2017-07-11

    Type XVII collagen (COL17) is a transmembrane protein located at the epidermal basement membrane zone. COL17 deficiency results in premature hair aging phenotypes and in junctional epidermolysis bullosa. Here, we show that COL17 plays a central role in regulating interfollicular epidermis (IFE) proliferation. Loss of COL17 leads to transient IFE hypertrophy in neonatal mice owing to aberrant Wnt signaling. The replenishment of COL17 in the neonatal epidermis of COL17-null mice reverses the proliferative IFE phenotype and the altered Wnt signaling. Physical aging abolishes membranous COL17 in IFE basal cells because of inactive atypical protein kinase C signaling and also induces epidermal hyperproliferation. The overexpression of human COL17 in aged mouse epidermis suppresses IFE hypertrophy. These findings demonstrate that COL17 governs IFE proliferation of neonatal and aged skin in distinct ways. Our study indicates that COL17 could be an important target of anti-aging strategies in the skin.

  10. Collagen macromolecular drug delivery systems

    International Nuclear Information System (INIS)

    Gilbert, D.L.

    1988-01-01

    The objective of this study was to examine collagen for use as a macromolecular drug delivery system by determining the mechanism of release through a matrix. Collagen membranes varying in porosity, crosslinking density, structure and crosslinker were fabricated. Collagen characterized by infrared spectroscopy and solution viscosity was determined to be pure and native. The collagen membranes were determined to possess native vs. non-native quaternary structure and porous vs. dense aggregate membranes by electron microscopy. Collagen monolithic devices containing a model macromolecule (inulin) were fabricated. In vitro release rates were found to be linear with respect to t 1/2 and were affected by crosslinking density, crosslinker and structure. The biodegradation of the collagen matrix was also examined. In vivo biocompatibility, degradation and 14 C-inulin release rates were evaluated subcutaneously in rats

  11. Clinical evaluation of GEM 21S® and a collagen membrane with a coronally advanced flap as a root coverage procedure in the treatment of gingival recession defects: A comparative study

    Directory of Open Access Journals (Sweden)

    Preetinder Singh

    2012-01-01

    Full Text Available Aim: Clinical evaluation of efficacy of rhPDGF-BB plus beta tricalcium phosphate (GEM 21S ® along with a collagen membrane in root coverage using a coronally advanced flap. Materials and Methods: This human case series evaluated the clinical outcome of rhPDGF-BB with beta-tricalcium phosphate (GEM 21S® and a collagen membrane in the treatment of recession defects using a coronally advanced flap. Patients were followed postoperatively, and healing was evaluated at 1, 3, and 6 months, with recession depth as the primary outcome measure. Results : This pioneer case series revealed a favorable tissue response to GEM 21S® and collagen membrane from both clinical and esthetic point of view in regenerative periodontal surgery.

  12. Collagenous Gastritis

    OpenAIRE

    Freeman, Hugh J.; Piercy, James R.A.; Raine, Robert J.

    1989-01-01

    A 54-year-old woman presented with nausea, vomiting and weight loss associated with impaired gastric emptying necessitating institution of parenteral nutrition. Subsequent studies revealed an unusual gastric mucosa! inflammatory process characterized by unique subepithelial collagenous deposits. Collagenous gastritis appears to be a distinct, possibly immune-mediated, chronic disorder, pathologically reminiscent of collagenous sprue and collagenous colitis.

  13. Amino acid duplication in the coiled-coil structure of collagen XVII alters its maturation and trimerization causing mild junctional epidermolysis bullosa.

    Science.gov (United States)

    Kroeger, Jasmin K; Hofmann, Silke C; Leppert, Juna; Has, Cristina; Franzke, Claus-Werner

    2017-02-01

    The function and stability of collagens depend on the accurate triple helix formation of three distinct polypeptide chains. Disruption of this triple-helical structure can result in connective-tissue disorders. Triple helix formation is thought to depend on three-stranded coiled-coil oligomerization sites within non-collagenous domains. However, only little is known about the physiological relevance of these coiled-coil structures. Transmembrane collagen XVII, also known as 180 kDa bullous pemphigoid antigen provides mechanical stability through the anchorage of epithelial cells to the basement membrane. Mutations in the collagen XVII gene, COL17A1, cause junctional epidermolysis bullosa (JEB), characterized by chronic trauma-induced skin blistering. Here we exploited a novel naturally occurring COL17A1 mutation, leading to an in-frame lysine duplication within the coiled-coil structure of the juxtamembranous NC16A domain of collagen XVII, which resulted in a mild phenotype of JEB due to reduced membrane-anchored collagen XVII molecules. This mutation causes structural changes in the mutant molecule and interferes with its maturation. The destabilized coiled-coil structure of the mutant collagen XVII unmasks a furin cleavage site that results in excessive and non-physiological ectodomain shedding during its maturation. Furthermore, it decreases its triple-helical stability due to defective coiled-coil oligomerization, which makes it highly susceptible to proteolytic degradation. As a consequence of altered maturation and decreased stability of collagen XVII trimers, reduced collagen XVII is incorporated into the cell membrane, resulting in compromised dermal-epidermal adhesion. Taken together, using this genetic model, we provide the first proof that alteration of the coiled-coil structure destabilizes oligomerization and impairs physiological shedding of collagen XVII in vivo. © The Author 2016. Published by Oxford University Press. All rights reserved. For

  14. Type VII and XVII Collagen mRNA Expressions in Regenerated Epidermal Laminae in Chronic Equine Laminitis

    Science.gov (United States)

    KUWANO, Atsutoshi; HASEGAWA, Telhisa; ARAI, Katsuhiko

    2009-01-01

    To confirm ability forming the basement membrane of the regenerated laminar epidermis (rLE) in chronic laminitis, expression of type VII and type XVII collagen mRNAs in the rLE was studied applying sequences of two type of murine collagens. On northern blot analysis, complement DNA (cDNA) probes adjusted from the murine type VII and type XVII collagen could hybridize with the equine mRNAs, and each signal was detected as single-bands at approximately 9.5 kb and 5.6 kb, respectively. Contrasting with the expression level of equine glyceraldehyde-3-phosphate dehydrogenease mRNA, the band of type VII collagen mRNA in laminitis was stronger than normal, but the type XVII collagen mRNA in laminitis was less than normal. By in situ hybridization, positive signals in response to the murine type VII and type XVII collagen mRNA probes could be detected in the equine laminitic rLE region. From these results, it is concluded that the keratinocytes constructing the rLE in chronic stage of laminitis can express type VII and type XVII collagen mRNAs and these expression patterns were different from the normal. PMID:24833961

  15. A clinical stydy on the effectiveness of slow - resorbing collagen membrane barrier therapy to guide regeneration in mandibular class II furcations in human

    Directory of Open Access Journals (Sweden)

    Abolfazli N

    1998-09-01

    Full Text Available The present clinical trial was designed to evaluate the regenerative potential of periodontal tissues in degree II"nfurcation defects at mandibular molars of human using a slow-resorbing collagen membrane and a surgical treatment"ntechnique based on the principles of guided tissue regeneration."nThe patient sampleinclude 8 subjects who had periodontal lessions in right and left mandibular molars regions, including moderate to advance periodonal destruction within the radicular area. Following a baseline examination including recording the clinical measurements (PD, Al, HC, F.G.M , the furcation- involved molars were randomly assigned in each patient to either a test or a control treatment procedure. Included the evevation of mucoperiosteal flaps, recording measurement from the cemento enamel junction (C.E.J directly coronal to the furcation area to the alveolar crest and to the base of the defect-Horizontal furcation measurements were also made using a William's probe, finally a collagen membrrane placed on the involved area to cover the entrance of the furcation and adjucent root surfaces as well as a portion of the alveolar bone apical to the crest. The flaps were repositioned and secured with interdental sutures. A procedure identical to the one used at the test teeth was Performed at the control teeth region with the exception of the placement of the collagen membrance. Following surgery all patients were placed on a plaque control regimen. All Patients received normal postsurgical care and at 6 month post-surgery were scheduled for re-entry surgery. Before re-entry surgery all clinical parameters recorded again. The re-entry mucoperiosteal flaps were designed to expose the furcation area for measurements, as describedabove. There was clinical improvement in all measurements made in both the test and control patients (especially in test group over the 6 month period. The horizontal and vertical furcation measurements did yield a

  16. Rare mutations and potentially damaging missense variants in genes encoding fibrillar collagens and proteins involved in their production are candidates for risk for preterm premature rupture of membranes.

    Directory of Open Access Journals (Sweden)

    Bhavi P Modi

    Full Text Available Preterm premature rupture of membranes (PPROM is the leading identifiable cause of preterm birth with ~ 40% of preterm births being associated with PPROM and occurs in 1% - 2% of all pregnancies. We hypothesized that multiple rare variants in fetal genes involved in extracellular matrix synthesis would associate with PPROM, based on the assumption that impaired elaboration of matrix proteins would reduce fetal membrane tensile strength, predisposing to unscheduled rupture. We performed whole exome sequencing (WES on neonatal DNA derived from pregnancies complicated by PPROM (49 cases and healthy term deliveries (20 controls to identify candidate mutations/variants. Genotyping for selected variants from the WES study was carried out on an additional 188 PPROM cases and 175 controls. All mothers were self-reported African Americans, and a panel of ancestry informative markers was used to control for genetic ancestry in all genetic association tests. In support of the primary hypothesis, a statistically significant genetic burden (all samples combined, SKAT-O p-value = 0.0225 of damaging/potentially damaging rare variants was identified in the genes of interest-fibrillar collagen genes, which contribute to fetal membrane strength and integrity. These findings suggest that the fetal contribution to PPROM is polygenic, and driven by an increased burden of rare variants that may also contribute to the disparities in rates of preterm birth among African Americans.

  17. Rare mutations and potentially damaging missense variants in genes encoding fibrillar collagens and proteins involved in their production are candidates for risk for preterm premature rupture of membranes.

    Science.gov (United States)

    Modi, Bhavi P; Teves, Maria E; Pearson, Laurel N; Parikh, Hardik I; Chaemsaithong, Piya; Sheth, Nihar U; York, Timothy P; Romero, Roberto; Strauss, Jerome F

    2017-01-01

    Preterm premature rupture of membranes (PPROM) is the leading identifiable cause of preterm birth with ~ 40% of preterm births being associated with PPROM and occurs in 1% - 2% of all pregnancies. We hypothesized that multiple rare variants in fetal genes involved in extracellular matrix synthesis would associate with PPROM, based on the assumption that impaired elaboration of matrix proteins would reduce fetal membrane tensile strength, predisposing to unscheduled rupture. We performed whole exome sequencing (WES) on neonatal DNA derived from pregnancies complicated by PPROM (49 cases) and healthy term deliveries (20 controls) to identify candidate mutations/variants. Genotyping for selected variants from the WES study was carried out on an additional 188 PPROM cases and 175 controls. All mothers were self-reported African Americans, and a panel of ancestry informative markers was used to control for genetic ancestry in all genetic association tests. In support of the primary hypothesis, a statistically significant genetic burden (all samples combined, SKAT-O p-value = 0.0225) of damaging/potentially damaging rare variants was identified in the genes of interest-fibrillar collagen genes, which contribute to fetal membrane strength and integrity. These findings suggest that the fetal contribution to PPROM is polygenic, and driven by an increased burden of rare variants that may also contribute to the disparities in rates of preterm birth among African Americans.

  18. Evaluation and Comparison of the Biopathology of Collagen and Inflammation in the Extracellular Matrix of Oral Epithelial Dysplasias and Inflammatory Fibrous Hyperplasia Using Picrosirius Red Stain and Polarising Microscopy: A Preliminary Study.

    Science.gov (United States)

    Varghese, Soma Susan; Sarojini, Sreenivasan Bargavan; George, Giju Baby; Vinod, Sankar; Mathew, Philips; Babu, Anulekh; Sebastian, Joseph

    2015-12-01

    The role of tumour inflammation and the dysplastic epithelial-stromal interactions on the nature of collagen fibres in the extracellular matrix of dysplastic epithelium is not fully understood. The present study was aimed to evaluate and compare the inflammation and pathological stromal collagen (loosely packed thin disorganized collagen) present in mild, moderate and severe epithelial dysplasias with that of inflammatory fibrous hyperplasias. The basement membrane intactness of epithelial dysplasias was also evaluated to determine if dysplastic epithelial mesenchymal interaction has any role in the integrity of stromal collagen in epithelial dysplasia. Oral epithelial dysplasias, inflammatory fibrous hyperplasia and normal oral mucosal samples were used for the study. Packing, thickness and orientation of collagen fibres in mild, moderate and severe grades of oral epithelial dysplasias (n = 24), inflammatory fibrous hyperplasia (n = 8) and normal oral mucosal samples (n = 8) were analysed based on the polarisation of collagen fibres in picrosirius red polarising stain under polarising microscope. All the grades of epithelial dysplasias showed greenish yellow birefringence confirming the presence of loosely arranged pathological collagen in the presence of moderate inflammation. All the cases of inflammatory fibrous hyperplasia showed red polarisation hue and moderate inflammation. A statistically significant difference was found in the packing and orientation of collagen when epithelial dysplasias and inflammatory fibrous hyperplasia were compared (P epithelial dysplasia, a statistically significant result was obtained (P epithelial dysplasia suggests that tumourigenic factors are released to connective tissue stroma much earlier than expected. Hence we suggest considering the integrity of extracellular matrix collagen, intactness of basement membrane and inflammation associated with dysplasia along with the anaplasia of epithelial cells in the microscopic

  19. Mac-2 binding protein is a cell-adhesive protein of the extracellular matrix which self-assembles into ring-like structures and binds beta1 integrins, collagens and fibronectin

    DEFF Research Database (Denmark)

    Sasaki, T; Brakebusch, C; Engel, J

    1998-01-01

    Human Mac-2 binding protein (M2BP) was prepared in recombinant form from the culture medium of 293 kidney cells and consisted of a 92 kDa subunit. The protein was obtained in a native state as indicated by CD spectroscopy, demonstrating alpha-helical and beta-type structure, and by protease...... in solid-phase assays to collagens IV, V and VI, fibronectin and nidogen, but not to fibrillar collagens I and III or other basement membrane proteins. The protein also mediated adhesion of cell lines at comparable strength with laminin. Adhesion to M2BP was inhibited by antibodies to integrin beta1...

  20. Histological and histomorphometric analysis of animal experimental dehiscence defect treated with three bio absorbable GTR collagen membrane

    Directory of Open Access Journals (Sweden)

    Parichehr Behfarnia

    2012-01-01

    Conclusion: The membrane-treated groups had a statistically significant increase in bone formation and connective tissue attachment compared to control groups. However, there are some differences among experimental groups, which should be considered in GTR treatments.

  1. Modeling pulmonary fibrosis by abnormal expression of telomerase/apoptosis/collagen V in experimental usual interstitial pneumonia

    Energy Technology Data Exchange (ETDEWEB)

    Parra, E.R.; Pincelli, M.S. [Departamento de Patologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Teodoro, W.R.; Velosa, A.P.P. [Disciplina de Reumatologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Martins, V.; Rangel, M.P.; Barbas-Filho, J.V.; Capelozzi, V.L. [Departamento de Patologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil)

    2014-06-04

    Limitations on tissue proliferation capacity determined by telomerase/apoptosis balance have been implicated in pathogenesis of idiopathic pulmonary fibrosis. In addition, collagen V shows promise as an inductor of apoptosis. We evaluated the quantitative relationship between the telomerase/apoptosis index, collagen V synthesis, and epithelial/fibroblast replication in mice exposed to butylated hydroxytoluene (BHT) at high oxygen concentration. Two groups of mice were analyzed: 20 mice received BHT, and 10 control mice received corn oil. Telomerase expression, apoptosis, collagen I, III, and V fibers, and hydroxyproline were evaluated by immunohistochemistry, in situ detection of apoptosis, electron microscopy, immunofluorescence, and histomorphometry. Electron microscopy confirmed the presence of increased alveolar epithelial cells type 1 (AEC1) in apoptosis. Immunostaining showed increased nuclear expression of telomerase in AEC type 2 (AEC2) between normal and chronic scarring areas of usual interstitial pneumonia (UIP). Control lungs and normal areas from UIP lungs showed weak green birefringence of type I and III collagens in the alveolar wall and type V collagen in the basement membrane of alveolar capillaries. The increase in collagen V was greater than collagens I and III in scarring areas of UIP. A significant direct association was found between collagen V and AEC2 apoptosis. We concluded that telomerase, collagen V fiber density, and apoptosis evaluation in experimental UIP offers the potential to control reepithelization of alveolar septa and fibroblast proliferation. Strategies aimed at preventing high rates of collagen V synthesis, or local responses to high rates of cell apoptosis, may have a significant impact in pulmonary fibrosis.

  2. The Role of Type IV Collagen in Developing Lens in Mouse Fetuses

    Directory of Open Access Journals (Sweden)

    Mehdi Jalali

    2009-09-01

    Full Text Available Objective(sExtracellular matrix (ECM and basement membrane (BM play important roles in many developmental processes during development and after birth. Among the components of the BM, collagen fibers specially type IV are the most important parts. The aim of this study was to determine the time when collagen type IV appears in the BM of lens structure during mouse embryonic development.Materials and MethodsIn this experimental study, 22 female Balb/C mice were randomly selected and were kept under normal condition, finding vaginal plug was assumed as day zero of pregnancy. From embryonic day 10 to 20, all specimens were sacrificed by cervical dislocation and their heads were fixed, serially sectioned and immunohistochemistry study for tracing collagen type IV in lens were carried out.ResultsOur data revealed that collagen type IV appeared at the early stage of gestation day 12 in BM of anterior epithelial lens cells and the amount of this protein gradually increased until days 15-17 in ECM and posterior capsule epithelium. After this period, severe reaction was not observed in any part of the lens.ConclusionThese findings establish the important role of collagen IV in developing optic cup and any changes during critical period of pregnancy may be result in severe visual system defect

  3. Immunohistochmical Study of Glomerular Mesengial Collagen IV Expression in Diabetic Balb/c Mice

    Directory of Open Access Journals (Sweden)

    M. Jalali

    2006-04-01

    Full Text Available Introduction & Objective: Extra-cellular matrix and basement membrane play important roles in many developmental phenamenon during development and after birth. Among the components of the basement membrane, collagen fibers specially type IV, are the most important part of this area. As kidney is one of the target organs in diabetes mellitus and diabetic nephropathy is a major cause of end stage-renal disease and result an increase in morbidity and mortality of effected individuals, therefore early diagnosis leads to better treatment. The aim of this investigation was to study the primary diagnostic parameters by special regards to collagen IV fibers.Materials & Methods: In this study, 24 male balb/c mice were divided into experimental and control groups. In experimental group, the beta cells of Langerhance were chemically destroyed by an injection of 160 mg/kg alloxan and subdivided in experimental groups 1 and 2. Controls were kept untreated. Experimental group 1and 2 were sacrified 8 and 16 weeks after treatment with alloxan respectively. The same procedure was performed for control group. Immunohistochmical studies were carried out using monocolonal antibody against collagen type IV in Glomeruli. In addition, using morphometrical and stereological methods the volume of the glumerles was compared in all groups.Results: Our finding showed that in experimental groups with special regards in 16 weeks diabetic mice, the rate of collagen type IV in basement membrane around the parietal layer of Bowman capsule, mesangial cells and endothelium of capillary in glomerules increased significantly compared to controls and experimental group 1 (p<0.05, while there was not a significant difference among experimental group 2 and controls. Our data also revealed that the number of mesangial cells as well as glomerular volume increased significantly in experimental 2 (4.635±0.289×106µm3 compared to experimental 1 (3.504±0.189×106µm3 and controls (3.422

  4. Type III collagen disorders: A case report and review of literature.

    Science.gov (United States)

    Anitha, A; Vankalakunti, Mahesha; Siddini, Vishwanath; Babu, Kishore; Bonu, Ravishankar; Ballal, Sudarshan

    2016-01-01

    Collagen type III is a normal component of interstitium and blood vessels. Collagenofibrotic glomerulopathy (CG) and nail patella syndrome (NPS) are the diseases of abnormal type III collagen deposition. In spite of these curved frayed structures with a periodicity of 45-60 nm are deposited in subendothelium and mesangium in CG, they are found only in the basement membrane in NPS. The clinical features of CG are confined to the kidney, NPS has associated extra-renal manifestations. Electron microscopy is essential to make the renal diagnosis in both these rare diseases. Both the entities considered to be systemic diseases evidence to suggest similar deposition in other organs, understanding etiopathogenesis and disease progression await research.

  5. Type I collagen gel induces Madin-Darby canine kidney cells to become fusiform in shape and lose apical-basal polarity.

    Science.gov (United States)

    Zuk, A; Matlin, K S; Hay, E D

    1989-03-01

    In the embryo, epithelia give rise to mesenchyme at specific times and places. Recently, it has been reported (Greenburg, G., and E. D. Hay. 1986. Dev. Biol. 115:363-379; Greenberg, G., and E. D. Hay. 1988. Development (Camb.). 102:605-622) that definitive epithelia can give rise to fibroblast-like cells when suspended within type I collagen gels. We wanted to know whether Madin-Darby canine kidney (MDCK) cells, an epithelial line, can form mesenchyme under similar conditions. Small explants of MDCK cells on basement membrane were suspended within or placed on top of extracellular matrix gels. MDCK cells on basement membrane gel are tall, columnar in shape, and ultrastructurally resemble epithelia transporting fluid and ions. MDCK explants cultured on type I collagen gel give rise to isolated fusiform-shaped cells that migrate over the gel surface. The fusiform cells extend pseudopodia and filopodia, lose cell membrane specializations, and develop an actin cortex around the entire cell. Unlike true mesenchymal cells, which express vimentin and type I collagen, fusiform cells produce both keratin and vimentin, continue to express laminin, and do not turn on type I collagen. Fusiform cells are not apically-basally polarized, but show mesenchymal cell polarity. Influenza hemagglutinin and virus budding localize to the front end or entire cell surface. Na,K-ATPase occurs intracellularly and also symmetrically distributes on the cell surface. Fodrin becomes diffusely distributed along the plasma membrane, ZO-1 cannot be detected, and desmoplakins distribute randomly in the cytoplasm. The loss of epithelial polarity and acquisition of mesenchymal cell polarity and shape by fusiform MDCK cells on type I collagen gel was previously unsuspected. The phenomenon may offer new opportunities for studying cytoplasmic and nuclear mechanisms regulating cell shape and polarity.

  6. Intra-Articular Injection of Human Synovial Membrane-Derived Mesenchymal Stem Cells in Murine Collagen-Induced Arthritis: Assessment of Immunomodulatory Capacity In Vivo

    Directory of Open Access Journals (Sweden)

    Minglu Yan

    2017-01-01

    Full Text Available The aim of this study was to evaluate the efficacy of human synovial membrane-derived MSCs (SM-MSCs in murine collagen-induced arthritis (CIA. Male mice (age 7–9 weeks were injected intra-articularly with SM-MSCs obtained from patients with osteoarthritis, on days 28, 32, and 38 after bovine type II collagen immunization. The efficacy of SM-MSCs in CIA was evaluated clinically and histologically. Cytokine profile analyses were performed by real-time polymerase chain reaction and multiplex analyses. Splenic helper T (Th cell and regulatory B cell subsets were analyzed by flow cytometry. Intra-articular SM-MSC injection ameliorated the clinical and histological severity of arthritis. Decrease in tumor necrosis factor-α, interferon-γ, and interleukin- (IL- 17A and increase in IL-10 production were observed after SM-MSC treatment. Flow cytometry showed that Th1 and Th17 cells decreased, whereas Th2, regulatory T (Treg, and PD-1+CXCR5+FoxP3+ follicular Treg cells increased in the spleens of SM-MSC-treated mice. Regulatory B cell analysis showed that CD21hiCD23hi transitional 2 cells, CD23lowCD21hi marginal zone cells, and CD19+CD5+CD1d+IL-10+ regulatory B cells increased following SM-MSC treatment. Our results demonstrated that SM-MSCs injected in inflamed joints in CIA had a therapeutic effect and could prevent arthritis development and suppress immune responses via immunoregulatory cell expansion.

  7. Measure Guideline: Basement Insulation Basics

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R.; Mantha, P.; Puttagunta, S.

    2012-10-01

    This guideline is intended to describe good practices for insulating basements in new and existing homes, and is intended to be a practical resources for building contractors, designers, and also to homeowners.

  8. Viability of chondrocytes seeded onto a collagen I/III membrane for matrix-induced autologous chondrocyte implantation.

    Science.gov (United States)

    Hindle, Paul; Hall, Andrew C; Biant, Leela C

    2014-11-01

    Cell viability is crucial for effective cell-based cartilage repair. The aim of this study was to determine the effect of handling the membrane during matrix-induced autologous chondrocyte implantation surgery on the viability of implanted chondrocytes. Images were acquired under five conditions: (i) Pre-operative; (ii) Handled during surgery; (iii) Cut edge; (iv) Thumb pressure applied; (v) Heavily grasped with forceps. Live and dead cell stains were used. Images were obtained for cell counting and morphology. Mean cell density was 6.60 × 10(5) cells/cm(2) (5.74-7.11 × 10(5) ) in specimens that did not have significant trauma decreasing significantly in specimens that had been grasped with forceps (p < 0.001) or cut (p = 0.004). Cell viability on delivery grade membrane was 75.1%(72.4-77.8%). This dropped to 67.4%(64.1-69.7%) after handling (p = 0.002), 56.3%(51.5-61.6%) after being thumbed (p < 0.001) and 28.8%(24.7-31.2%) after crushing with forceps (p < 0.001). When cut with scissors there was a band of cell death approximately 275 µm in width where cell viability decreased to 13.7%(10.2-18.2%, p < 0.001). Higher magnification revealed cells without the typical rounded appearance of chondrocytes. We found that confocal laser-scanning microscope (CLSM) can be used to quantify and image the fine morphology of cells on a matrix-induced autologous chondrocyte implantation (MACI) membrane. Careful handling of the membrane is essential to minimise chondrocyte death during surgery. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  9. Preparation of a collagen/polymer hybrid gel designed for tissue membranes. Part I: controlling the polymer-collagen cross-linking process using an ethanol/water co-solvent.

    Science.gov (United States)

    Nam, Kwangwoo; Kimura, Tsuyoshi; Funamoto, Seiichi; Kishida, Akio

    2010-02-01

    The drawback with collagen/2-methacryloyloxyethyl phosphorylcholine (MPC) polymer hybrid gels (collagen/phospholipid polymer hybrid gels) prepared in alkaline morpholinoethane sulfonic acid (MES) aqueous solution is that the cross-linking rate between the polymer and the collagen is low. To solve this problem, ethanol has been adopted as the reaction solvent, to prevent 1-ethyl-3-(3-dimethylaminopropyl)-1-carbodiimide hydrochloride (EDC) hydrolysis. Alterations in the ethanol mole concentration changed the cross-linking rate between the MPC polymer and the collagen gel. Prevention of EDC hydrolysis is clearly observed; protonation of carboxyl groups implies that the ratio of ethanol to water should be controlled. The polymer shows signs of penetration into the collagen gel layer, thus forming a totally homogeneous phase gel. This affects the mechanical strength of the collagen gel, making the gel much stiffer and brittle with an increase in the swelling ratio, as compared with that prepared in MES buffer. However, it is possible to obtain a collagen/phospholipid polymer hybrid gel with a high polymer portion and the cross-linking rate can be successfully controlled.

  10. Viruses in the Oceanic Basement.

    Science.gov (United States)

    Nigro, Olivia D; Jungbluth, Sean P; Lin, Huei-Ting; Hsieh, Chih-Chiang; Miranda, Jaclyn A; Schvarcz, Christopher R; Rappé, Michael S; Steward, Grieg F

    2017-03-07

    Microbial life has been detected well into the igneous crust of the seafloor (i.e., the oceanic basement), but there have been no reports confirming the presence of viruses in this habitat. To detect and characterize an ocean basement virome, geothermally heated fluid samples (ca. 60 to 65°C) were collected from 117 to 292 m deep into the ocean basement using seafloor observatories installed in two boreholes (Integrated Ocean Drilling Program [IODP] U1362A and U1362B) drilled in the eastern sediment-covered flank of the Juan de Fuca Ridge. Concentrations of virus-like particles in the fluid samples were on the order of 0.2 × 10 5 to 2 × 10 5  ml -1 ( n = 8), higher than prokaryote-like cells in the same samples by a factor of 9 on average (range, 1.5 to 27). Electron microscopy revealed diverse viral morphotypes similar to those of viruses known to infect bacteria and thermophilic archaea. An analysis of virus-like sequences in basement microbial metagenomes suggests that those from archaeon-infecting viruses were the most common (63 to 80%). Complete genomes of a putative archaeon-infecting virus and a prophage within an archaeal scaffold were identified among the assembled sequences, and sequence analysis suggests that they represent lineages divergent from known thermophilic viruses. Of the clustered regularly interspaced short palindromic repeat (CRISPR)-containing scaffolds in the metagenomes for which a taxonomy could be inferred (163 out of 737), 51 to 55% appeared to be archaeal and 45 to 49% appeared to be bacterial. These results imply that the warmed, highly altered fluids in deeply buried ocean basement harbor a distinct assemblage of novel viruses, including many that infect archaea, and that these viruses are active participants in the ecology of the basement microbiome. IMPORTANCE The hydrothermally active ocean basement is voluminous and likely provided conditions critical to the origins of life, but the microbiology of this vast habitat is not

  11. Viruses in the Oceanic Basement

    Directory of Open Access Journals (Sweden)

    Olivia D. Nigro

    2017-03-01

    Full Text Available Microbial life has been detected well into the igneous crust of the seafloor (i.e., the oceanic basement, but there have been no reports confirming the presence of viruses in this habitat. To detect and characterize an ocean basement virome, geothermally heated fluid samples (ca. 60 to 65°C were collected from 117 to 292 m deep into the ocean basement using seafloor observatories installed in two boreholes (Integrated Ocean Drilling Program [IODP] U1362A and U1362B drilled in the eastern sediment-covered flank of the Juan de Fuca Ridge. Concentrations of virus-like particles in the fluid samples were on the order of 0.2 × 105 to 2 × 105 ml−1 (n = 8, higher than prokaryote-like cells in the same samples by a factor of 9 on average (range, 1.5 to 27. Electron microscopy revealed diverse viral morphotypes similar to those of viruses known to infect bacteria and thermophilic archaea. An analysis of virus-like sequences in basement microbial metagenomes suggests that those from archaeon-infecting viruses were the most common (63 to 80%. Complete genomes of a putative archaeon-infecting virus and a prophage within an archaeal scaffold were identified among the assembled sequences, and sequence analysis suggests that they represent lineages divergent from known thermophilic viruses. Of the clustered regularly interspaced short palindromic repeat (CRISPR-containing scaffolds in the metagenomes for which a taxonomy could be inferred (163 out of 737, 51 to 55% appeared to be archaeal and 45 to 49% appeared to be bacterial. These results imply that the warmed, highly altered fluids in deeply buried ocean basement harbor a distinct assemblage of novel viruses, including many that infect archaea, and that these viruses are active participants in the ecology of the basement microbiome.

  12. Collagenous sprue

    DEFF Research Database (Denmark)

    Soendergaard, Christoffer; Riis, Lene Buhl; Nielsen, Ole Haagen

    2014-01-01

    disease and together with frequent histological findings like mucosal thinning and intraepithelial lymphocytosis the diagnosis may be hard to reach without awareness of this condition. While coeliac disease is treated using gluten restriction, collagenous sprue is, however, not improved...... by this intervention. In cases of diet-refractory 'coeliac disease' it is therefore essential to consider collagenous sprue to initiate treatment at an early stage to prevent the fibrotic progression. Here, we report a case of a 78-year-old man with collagenous sprue and present the clinical and histological...

  13. Hybrid Membranes of PLLA/Collagen for Bone Tissue Engineering: A Comparative Study of Scaffold Production Techniques for Optimal Mechanical Properties and Osteoinduction Ability

    Directory of Open Access Journals (Sweden)

    Flávia Gonçalves

    2015-01-01

    Full Text Available Synthetic and natural polymer association is a promising tool in tissue engineering. The aim of this study was to compare five methodologies for producing hybrid scaffolds for cell culture using poly-l-lactide (PLLA and collagen: functionalization of PLLA electrospun by (1 dialkylamine and collagen immobilization with glutaraldehyde and by (2 hydrolysis and collagen immobilization with carbodiimide chemistry; (3 co-electrospinning of PLLA/chloroform and collagen/hexafluoropropanol (HFP solutions; (4 co-electrospinning of PLLA/chloroform and collagen/acetic acid solutions and (5 electrospinning of a co-solution of PLLA and collagen using HFP. These materials were evaluated based on their morphology, mechanical properties, ability to induce cell proliferation and alkaline phosphatase activity upon submission of mesenchymal stem cells to basal or osteoblastic differentiation medium (ODM. Methods (1 and (2 resulted in a decrease in mechanical properties, whereas methods (3, (4 and (5 resulted in materials of higher tensile strength and osteogenic differentiation. Materials yielded by methods (2, (3 and (5 promoted osteoinduction even in the absence of ODM. The results indicate that the scaffold based on the PLLA/collagen blend exhibited optimal mechanical properties and the highest capacity for osteodifferentiation and was the best choice for collagen incorporation into PLLA in bone repair applications.

  14. Evaluation of efficacy of a novel resorbable collagen membrane for root coverage of Miller's Class I and Class II recession in the maxillary anteriors and premolars

    Directory of Open Access Journals (Sweden)

    Krutika Kapare

    2016-01-01

    Full Text Available Background: There are several surgical techniques in literature that have been used to perform root coverage (RC. Currently, the use of a resorbable collagen membrane (RCM as a guided tissue regenerative material is one of the highly sought treatment modalities. The present study aimed at evaluating the clinical outcome of RC in the treatment of Miller's Class I and II recession defects in maxillary anteriors and premolars by coronally advanced flap (CAF with and without RCM. Materials and Methods: This split-mouth study (bilateral buccal recession defects was randomized to include 15 test (CAF + membrane and 15 control (CAF alone sites. Clinical parameters included gingival recession depth (RD, probing pocket depth (PPD, clinical attachment level (CAL, and keratinized tissue height (KTH measured at baseline and 9 months postoperatively. Results: Both test and control groups showed statistically significant (P < 0.05 reductions in RD (1.54 ± 0.46 mm and 1.60 ± 0.07 mm, PPD (0.53 ± 0.15 mm and 0.94 ± 0.10 mm, increase in KTH (0.67 ± 0.90 mm and 0.73 ± 0.14 mm and CAL (1.94 ± 0.27 mm and 2.60 ± 0.19 mm when comparing the 9-month data from baseline. The present study showed that mean improvement in RD was 1.60 ± 0.507 and 1.53 ± 0.64 mm in both test and control groups, respectively. Mean percent RC was 58.33% ±12.19% and 56.22% ±10.22% for test and control groups, respectively. However, there were no statistically significant differences between groups for RD, PPD, KTH, and CAL. Conclusion: The results of this study suggest that both the groups CAF (control and CAF and RCM (test could be successfully used to treat Miller's Class I and II gingival recession defects and also demonstrated an overall significant improvement in all the assessed clinical parameters. However, there was a greater reduction of gingival RD with the use of RCM when compared with the group of CAF alone.

  15. Development of a Neo-Epitope Specific Assay for Serological Assessment of Type VII Collagen Turnover and Its Relevance in Fibroproliferative Disorders.

    Science.gov (United States)

    Sand, Jannie M B; Lamy, Patricia; Juhl, Pernille; Siebuhr, Anne Sofie; Iversen, Line V; Nawrocki, Arkadiusz; Larsen, Martin R; Domsic, Robyn T; Franchimont, Nathalie; Chavez, Juan; Karsdal, Morten A; Leeming, Diana J

    2018-03-01

    Type VII collagen is the main component of the anchoring fibrils connecting the basement membrane to the underlying interstitial matrix. Mutations in the type VII collagen gene cause dystrophic epidermolysis bullosa. Increased levels of type VII collagen in the skin have been reported in patients with systemic sclerosis (SSc), whereas reduced levels in the airways have been related to asthma. This indicates that type VII collagen plays an important part in upholding tissue integrity and that its remodeling may lead to pathological states. The aim of this study was to investigate the role of type VII collagen remodeling in fibroproliferative disorders. We produced monoclonal antibody targeting a specific fragment of type VII collagen (C7M) released to the systemic circulation and developed a neo-epitope specific competitive enzyme-linked immunosorbent assay (ELISA). Biological relevance was evaluated in serum from patients with SSc or chronic obstructive pulmonary disease (COPD). The C7M ELISA was technically robust and specific for the C7M neo-epitope. Serum C7M levels were significantly elevated in two cohorts of patients with SSc and in patients with COPD as compared with healthy individuals (P collagen turnover in serum. Elevated serum C7M levels indicated that the turnover rate of type VII collagen was significantly increased in patients with SSc or COPD, suggesting a pathological role. Thus, the C7M ELISA may become useful in future investigations of type VII collagen turnover in fibroproliferative disorders, and it may prove a valuable tool for evaluating novel anti-fibrotic drugs.

  16. Persistence of collagen type II-specific T-cell clones in the synovial membrane of a patient with rheumatoid arthritis

    International Nuclear Information System (INIS)

    Londei, M.; Savill, C.M.; Verhoef, A.; Brennan, F.; Leech, Z.A.; Feldmann, M.; Duance, V.; Maini, R.N.

    1989-01-01

    Rheumatoid arthritis is an autoimmune disease characterized by T-cell infiltration of the synovium of joints. Analysis of the phenotype and antigen specificity of the infiltrating cells may thus provide insight into the pathogenesis of rheumatoid arthritis. T cells were cloned with interleukin 2, a procedure that selects for in vivo-activated cells. All clones had the CD4 CDW29 phenotype. Their antigen specificity was tested by using a panel of candidate joint autoantigens. Four of 17 reacted against autologous blood mononuclear cells. Two clones proliferated in response to collagen type II. After 21 months, another set of clones was derived from synovial tissue of the same joint. One of eight clones tested showed a strong proliferative response against collagen type II. The uncloned synovial T cells of a third operation from another joint also responded to collagen type II. The persistence of collagen type II-specific T cells in active rheumatoid joints over a period of 3 years suggests that collagen type II could be one of the autoantigens involved in perpetuating the inflammatory process in rheumatoid arthritis

  17. Mutations in collagen 18A1 (COL18A1 and their relevance to the human phenotype

    Directory of Open Access Journals (Sweden)

    Passos-Bueno Maria Rita

    2006-01-01

    Full Text Available Collagen XVIII, a proteoglycan, is a component of basement membranes (BMs. There are three distinct isoforms that differ only by their N-terminal, but with a specific pattern of tissue and developmental expression. Cleavage of its C-terminal produces endostatin, an inhibitor of angiogenesis. In its N-terminal, there is a frizzled motif which seems to be involved in Wnt signaling. Mutations in this gene cause Knobloch syndrome KS, an autosomal recessive disorder characterized by vitreoretinal and macular degeneration and occipital encephalocele. This review discusses the effect of both rare and polymorphic alleles in the human phenotype, showing that deficiency of one of the collagen XVIII isoforms is sufficient to cause KS and that null alleles causing deficiency of all collagen XVIII isoforms are associated with a more severe ocular defect. This review besides illustrating the functional importance of collagen XVIII in eye development and its structure maintenance throughout life, it also shows its role in other tissues and organs, such as nervous system and kidney.

  18. Comparative surface energetic study of Matrigel®and collagen I interactions with endothelial cells.

    Science.gov (United States)

    Hill, Michael J; Sarkar, Debanjan

    2017-07-01

    Understanding of the surface energetic aspects of the spontaneously deposited proteins on biomaterial surfaces and how this influences cell adhesion and differentiation is an area of regenerative medicine that has not received adequate attention. Current controversies surround the role of the biomaterial substratum surface chemistry, the range of influence of said substratum, and the effects of different surface energy components of the protein interface. Endothelial cells (ECs) are a highly important cell type for regenerative medicine applications, such as tissue engineering, and In-vivo they interact with collagen I based stromal tissue and basement membranes producing different behavioral outcomes. The surface energetic properties of these tissue types and how they control EC behavior is not well known. In this work we studied the surface energetic properties of collagen I and Matrigel ® on various previously characterized substratum polyurethanes (PU) via contact angle analysis and examined the subsequent EC network forming characteristics. A combinatorial surface energy approach was utilized that compared Zisman's critical surface tension, Kaelble's numerical method, and van Oss-Good-Chaudhury theory (vOGCT). We found that the unique, rapid network forming characteristics of ECs on Matrigel ® could be attributed to the apolar or monopolar basic interfacial characteristics according to Zisman/Kaelble or vOGCT, respectively. We also found a lack of significant substratum influence on EC network forming characteristics for Matrigel ® but collagen I showed a distinct influence where more apolar PU substrata tended to produce higher Lewis acid character collagen I interfaces which led to a greater interaction with ECs. Collagen I interfaces on more polar PU substrata lacked Lewis acid character and led to similar EC network characteristics as Matrigel ® . We hypothesized that bipolar character of the protein film favored cell-substratum over cell-cell adhesive

  19. Guided bone regeneration in standardized calvarial defects using beta-tricalcium phosphate and collagen membrane: a real-time in vivo micro-computed tomographic experiment in rats.

    Science.gov (United States)

    Ramalingam, Sundar; Al-Rasheed, Abdulaziz; ArRejaie, Aws; Nooh, Nasser; Al-Kindi, Mohammed; Al-Hezaimi, Khalid

    2016-05-01

    Guided bone regeneration (GBR) procedures using graft materials have been used for reconstruction of osseous defects. The aim of the present in vivo micro-computed tomographic (µCT) and histologic study was to assess in real time the bone regeneration at GBR sites in standardized experimental calvarial defects (diameter 3.3 mm) using β-tricalcium phosphate (β-TCP) with and without collagen membrane (CM). A single full-thickness calvarial defect was created on the left parietal bone in young female Wistar albino rats (n = 30) weighing approximately 300 g and aged about 6 weeks. The animals were randomly divided into three groups for treatment, based on calvarial defect filling material: (1) control group (n = 10); (2) β-TCP + CM group (n = 10); (3) β-TCP group (n = 10). Real-time in vivo µCT analyses were performed immediately after surgery and at 2, 4, 6 and 10 weeks to determine the volume and mineral density of the newly formed bone (BVNFB, MDNFB) and remaining β-TCP particles (VRBP, MDRBP). The animals were killed at 10 weeks and calvarial specimens were evaluated histologically. In the control group, MDNFB increased significantly at 6 weeks (0.32 ± 0.002 g/mm(3), P < 0.01) compared to that at baseline. In β-TCP + CM group, BVNFB (1.10 ± 0.12 mm(3), P < 0.01) and MDNFB (0.13 ± 0.02 g/mm(3), P < 0.01) significantly increased at the 4th week than baseline. In the β-TCP group, BVNFB (1.13 ± 0.12 mm(3), P < 0.01) and MDNFB (0.14 ± 0.01 g/mm(3), P < 0.01) significantly increased at 6 weeks compared to that at baseline. Significant reduction in VRBP was neither seen in the β-TCP + CM group nor in the β-TCP group. While in the β-TCP + CM group MDRBP was reduced significantly at 6 weeks (0.44 ± 0.9 g/mm(3), P < 0.01) from baseline (0.98 ± 0.03 g/mm(3)), similar significant reduction in MDRBP from baseline (0.92 ± 0.07 g/mm(3)) was seen only at 10 weeks (0.45 ± 0.06 g/mm(3), P < 0.05) in the β-TCP group. Histologic findings at 10 weeks revealed

  20. Evaluation of autogenous PRGF+β-TCP with or without a collagen membrane on bone formation and implant osseointegration in large size bone defects. A preclinical in vivo study.

    Science.gov (United States)

    Batas, Leonidas; Stavropoulos, Andreas; Papadimitriou, Serafim; Nyengaard, Jens R; Konstantinidis, Antonios

    2016-08-01

    The aim of this study was to evaluate whether the adjunctive use of a collagen membrane enhances bone formation and implant osseointegration in non-contained defects grafted with chair-side prepared autologous platelet-rich growth factor (PRGF) adsorbed on a β-TCP particulate carrier. Large box-type defects (10 × 6 mm; W × D) were prepared in the edentulated and completely healed mandibles of six Beagles dogs. An implant with moderately rough surface was placed in the center of each defect leaving the coronal 6 mm of the implant not covered with bone. The remaining defect space was then filled out with chair-side prepared autologous PRGF adsorbed on β-TCP particles and either covered with a collagen membrane (PRGF/β-TCP+CM) (6 defects) or left without a membrane (PRGF/β-TCP) (5 defects). Histology 4 months post-op showed new lamellar and woven bone formation encompassing almost entirely the defect and limited residual β-TCP particles. Extent of osseointegration of the previously exposed portion of the implants varied, but in general was limited. Within the defect, new mineralized bone (%) averaged 43.2 ± 9.86 vs. 39.9 ± 13.7 in the PRGF/β-TCP+CM and PRGF/β-TCP group (P = 0.22) and relative mineralized bone-to-implant contact (%) averaged 26.2 ± 16.45 vs. 35.91 ± 24.45, respectively (P = 0.5). First, bone-to-implant contact from the implant top was 4.1 ± 1.5 and 3.2 ± 2.3 (P = 0.9), in the PRGF/β-TCP+CM and PRGF/β-TCP group, respectively. Implantation of chair-side prepared autologous PRGF adsorbed on a β-TCP carrier in non-contained peri-implant defects resulted in large amounts of bone regeneration, but osseointegration was limited. Provisions for GBR with a collagen membrane did not significantly enhance bone regeneration or implant osseointegration. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Normal skin and hypertrophic scar fibroblasts differentially regulate collagen and fibronectin expression as well as mitochondrial membrane potential in response to basic fibroblast growth factor.

    Science.gov (United States)

    Song, Rui; Bian, Hui-Ning; Lai, Wen; Chen, Hua-De; Zhao, Ke-Seng

    2011-05-01

    Basic fibroblast growth factor (bFGF) regulates skin wound healing; however, the underlying mechanism remains to be defined. In the present study, we determined the effects of bFGF on the regulation of cell growth as well as collagen and fibronectin expression in fibroblasts from normal human skin and from hypertrophic scars. We then explored the involvement of mitochondria in mediating bFGF-induced effects on the fibroblasts. We isolated and cultivated normal and hypertrophic scar fibroblasts from tissue biopsies of patients who underwent plastic surgery for repairing hypertrophic scars. The fibroblasts were then treated with different concentrations of bFGF (ranging from 0.1 to 1000 ng/mL). The growth of hypertrophic scar fibroblasts became slower with selective inhibition of type I collagen production after exposure to bFGF. However, type III collagen expression was affected in both normal and hypertrophic scar fibroblasts. Moreover, fibronectin expression in the normal fibroblasts was up-regulated after bFGF treatment. bFGF (1000 ng/mL) also induced mitochondrial depolarization in hypertrophic scar fibroblasts (P fibroblasts (P fibroblasts following treatment with bFGF (P fibroblasts of the normal skin and hypertrophic scars, indicating that bFGF may play a role in the early phase of skin wound healing and post-burn scar formation.

  2. Marine-derived collagen biomaterials from echinoderm connective tissues.

    Science.gov (United States)

    Ferrario, Cinzia; Leggio, Livio; Leone, Roberta; Di Benedetto, Cristiano; Guidetti, Luca; Coccè, Valentina; Ascagni, Miriam; Bonasoro, Francesco; La Porta, Caterina A M; Candia Carnevali, M Daniela; Sugni, Michela

    2017-07-01

    The use of marine collagens is a hot topic in the field of tissue engineering. Echinoderms possess unique connective tissues (Mutable Collagenous Tissues, MCTs) which can represent an innovative source of collagen to develop collagen barrier-membranes for Guided Tissue Regeneration (GTR). In the present work we used MCTs from different echinoderm models (sea urchin, starfish and sea cucumber) to produce echinoderm-derived collagen membranes (EDCMs). Commercial membranes for GTR or soluble/reassembled (fibrillar) bovine collagen substrates were used as controls. The three EDCMs were similar among each other in terms of structure and mechanical performances and were much thinner and mechanically more resistant than the commercial membranes. Number of fibroblasts seeded on sea-urchin membranes were comparable to the bovine collagen substrates. Cell morphology on all EDCMs was similar to that of structurally comparable (reassembled) bovine collagen substrates. Overall, echinoderms, and sea urchins particularly, are alternative collagen sources to produce efficient GTR membranes. Sea urchins display a further advantage in terms of eco-sustainability by recycling tissues from food wastes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Marine-derived collagen biomaterials from echinoderm connective tissues

    KAUST Repository

    Ferrario, Cinzia

    2016-03-31

    The use of marine collagens is a hot topic in the field of tissue engineering. Echinoderms possess unique connective tissues (Mutable Collagenous Tissues, MCTs) which can represent an innovative source of collagen to develop collagen barrier-membranes for Guided Tissue Regeneration (GTR). In the present work we used MCTs from different echinoderm models (sea urchin, starfish and sea cucumber) to produce echinoderm-derived collagen membranes (EDCMs). Commercial membranes for GTR or soluble/reassembled (fibrillar) bovine collagen substrates were used as controls. The three EDCMs were similar among each other in terms of structure and mechanical performances and were much thinner and mechanically more resistant than the commercial membranes. Number of fibroblasts seeded on sea-urchin membranes were comparable to the bovine collagen substrates. Cell morphology on all EDCMs was similar to that of structurally comparable (reassembled) bovine collagen substrates. Overall, echinoderms, and sea urchins particularly, are alternative collagen sources to produce efficient GTR membranes. Sea urchins display a further advantage in terms of eco-sustainability by recycling tissues from food wastes.

  4. Evaluation of biodegradation and biocompatibility of collagen ...

    Indian Academy of Sciences (India)

    decreases, the COL–CHI–ALP membrane being in the non-haemolytic domain, while the COL–CHI–ALP–GA membrane has a haemolytic index greater than 2, and is slightly haemolytic. Keywords. Collagen; chitosan; biocompatibility; adsorption. 1. Introduction. Immobilization of biomolecules on biopolymeric supports is.

  5. A multicenter randomized controlled clinical trial using a new resorbable non-cross-linked collagen membrane for guided bone regeneration at dehisced single implant sites: interim results of a bone augmentation procedure.

    Science.gov (United States)

    Wessing, Bastian; Urban, Istvan; Montero, Eduardo; Zechner, Werner; Hof, Markus; Alández Chamorro, Javier; Alández Martin, Nuria; Polizzi, Giovanni; Meloni, Silvio; Sanz, Mariano

    2017-11-01

    To compare clinical performance of a new resorbable non-cross-linked collagen membrane, creos xenoprotect (CXP), with a reference membrane (BG) for guided bone regeneration at dehisced implant sites. This randomized controlled clinical trial enrolled patients with expected dehiscence defects following implant placement to restore single teeth in the maxillary and mandibular esthetic zone and premolar area. Implants were placed using a two-stage surgical protocol with delayed loading. Bone augmentation material placed at the implant surface was immobilized with CXP or BG membrane. Soft tissue health was followed during the healing period, and the defect size was measured at reentry and 6 months after implant placement. Of the 49 included patients, 24 were treated with CXP and 25 with BG. Patient characteristics did not differ between the two arms. In the CXP arm, the defect height at implant insertion was (mean ± SD) 5.1 ± 2.1 mm (n = 24) and reduced at reentry by 81% to 1.0 ± 1.3 mm (n = 23). In the BG arm, the defect height at implant insertion was 4.9 ± 1.9 mm (n = 25) and reduced at reentry by 62% to 1.7 ± 2.1 mm (n = 24). Assuming a margin of non-inferiority of 1 mm, CXP was non-inferior to BG. Membrane exposure rate was highest at week 3 in both arms, reaching 16.7% for BG and 8.7% for CXP. The new resorbable non-cross-linked collagen membrane facilitates bone gain to support implant placement in expected dehiscence defects. The observed trend toward higher mean bone gain and lower exposure rate with CXP compared to BG should be further investigated. © 2016 The Authors. Clinical Oral Implants Research Published by John Wiley & Sons Ltd.

  6. Location and distribution of non-collagenous matrix proteins in musculoskeletal tissues of rat.

    Science.gov (United States)

    Kannus, P; Jozsa, L; Järvinen, T A; Järvinen, T L; Kvist, M; Natri, A; Järvinen, M

    1998-11-01

    The study assessed immunohistochemically the location and distribution of various non-collagenous matrix proteins (fibronectin, laminin, tenascin-C, osteocalcin, thrombospondin-1, vitronectin and undulin) in musculoskeletal tissues of rat. Fibronectin and thrombospondin-1 were found to be ubiquitous in the studied tissues. High immunoreactivity of these proteins was found in the extracellular matrix of the anatomical sites where firm bindings are needed, i.e. between muscle fibres and fibre bundles, between the collagen fibres of a tendon and at myotendinous junctions, osteotendinous junctions and articular cartilage. Tenascin-C was found in the extracellular matrix of regions where especially high forces are transmitted from one tissue component to the other, such as myotendinous junctions and osteotendinous junctions. Laminin was demonstrated in the basement membranes of the muscle cells and capillaries of the muscle-tendon units. Osteocalcin immunoreactivity concentrated in the extracellular matrix of areas of newly formed bone tissue, i.e. in the subperiosteal and subchondral regions, osteoid tissue and mineralized fibrocartilage zone of the osteotendinous junction. Mild vitronectin activity could be seen in the extracellular matrix of the osteotendinous and myotendinous junctions, and high activity around the bone marrow cells. Undulin could be demonstrated in the extracellular matrix (i.e. on the collagen fibres) of the tendon and epimysium only. However, it was co-distributed with fibronectin and tenascin-C. Together, these findings on the normal location and distribution of these non-collagenous proteins in the musculoskeletal tissues help to form the basis of knowledge against which the location and distribution of the these proteins in various pathological processes could be compared.

  7. Irradiation Alters MMP-2/TIMP-2 System and Collagen Type IV Degradation in Brain

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Hee [School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia (United States); Warrington, Junie P.; Sonntag, William E. [Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma (United States); Lee, Yong Woo, E-mail: ywlee@vt.edu [School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia (United States); Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia (United States)

    2012-04-01

    Purpose: Blood-brain barrier (BBB) disruption is one of the major consequences of radiation-induced normal tissue injury in the central nervous system. We examined the effects of whole-brain irradiation on matrix metalloproteinases (MMPs)/tissue inhibitors of metalloproteinases (TIMPs) and extracellular matrix (ECM) degradation in the brain. Methods and Materials: Animals received either whole-brain irradiation (a single dose of 10 Gy {gamma}-rays or a fractionated dose of 40 Gy {gamma}-rays, total) or sham-irradiation and were maintained for 4, 8, and 24 h following irradiation. mRNA expression levels of MMPs and TIMPs in the brain were analyzed by real-time reverse transcriptase-polymerase chain reaction (PCR). The functional activity of MMPs was measured by in situ zymography, and degradation of ECM was visualized by collagen type IV immunofluorescent staining. Results: A significant increase in mRNA expression levels of MMP-2, MMP-9, and TIMP-1 was observed in irradiated brains compared to that in sham-irradiated controls. In situ zymography revealed a strong gelatinolytic activity in the brain 24 h postirradiation, and the enhanced gelatinolytic activity mediated by irradiation was significantly attenuated in the presence of anti-MMP-2 antibody. A significant reduction in collagen type IV immunoreactivity was also detected in the brain at 24 h after irradiation. In contrast, the levels of collagen type IV were not significantly changed at 4 and 8 h after irradiation compared with the sham-irradiated controls. Conclusions: The present study demonstrates for the first time that radiation induces an imbalance between MMP-2 and TIMP-2 levels and suggests that degradation of collagen type IV, a major ECM component of BBB basement membrane, may have a role in the pathogenesis of brain injury.

  8. Irradiation Alters MMP-2/TIMP-2 System and Collagen Type IV Degradation in Brain

    International Nuclear Information System (INIS)

    Lee, Won Hee; Warrington, Junie P.; Sonntag, William E.; Lee, Yong Woo

    2012-01-01

    Purpose: Blood-brain barrier (BBB) disruption is one of the major consequences of radiation-induced normal tissue injury in the central nervous system. We examined the effects of whole-brain irradiation on matrix metalloproteinases (MMPs)/tissue inhibitors of metalloproteinases (TIMPs) and extracellular matrix (ECM) degradation in the brain. Methods and Materials: Animals received either whole-brain irradiation (a single dose of 10 Gy γ-rays or a fractionated dose of 40 Gy γ-rays, total) or sham-irradiation and were maintained for 4, 8, and 24 h following irradiation. mRNA expression levels of MMPs and TIMPs in the brain were analyzed by real-time reverse transcriptase-polymerase chain reaction (PCR). The functional activity of MMPs was measured by in situ zymography, and degradation of ECM was visualized by collagen type IV immunofluorescent staining. Results: A significant increase in mRNA expression levels of MMP-2, MMP-9, and TIMP-1 was observed in irradiated brains compared to that in sham-irradiated controls. In situ zymography revealed a strong gelatinolytic activity in the brain 24 h postirradiation, and the enhanced gelatinolytic activity mediated by irradiation was significantly attenuated in the presence of anti-MMP-2 antibody. A significant reduction in collagen type IV immunoreactivity was also detected in the brain at 24 h after irradiation. In contrast, the levels of collagen type IV were not significantly changed at 4 and 8 h after irradiation compared with the sham-irradiated controls. Conclusions: The present study demonstrates for the first time that radiation induces an imbalance between MMP-2 and TIMP-2 levels and suggests that degradation of collagen type IV, a major ECM component of BBB basement membrane, may have a role in the pathogenesis of brain injury.

  9. Periodontal Regenerative Therapy of Intrabony Defects Using Deproteinized Bovine Bone Mineral in Combination with Collagen Barrier Membrane: A Multicenter Prospective Case-Series Study.

    Science.gov (United States)

    Irokawa, Daisuke; Okubo, Nobuki; Nikaido, Masahiko; Shimizu, Hiroyasu; Konobu, Hiroyuki; Matsui, Tokuo; Fujita, Takahisa; Goto, Hiroaki; Takeuchi, Takahiro; Ishii, Yoshihito; Saito, Atsushi

    This multicenter prospective case series study aimed to evaluate the outcome of periodontal regenerative therapy using a deproteinized bovine bone mineral (DBBM) in combination with a collagen barrier (CB) in the treatment of intrabony defects. A total of 36 nonsmoking patients with chronic periodontitis were recruited in five centers in Japan. All patients had at least one intrabony defect of ≥ 3 mm. The surgical procedures included access for debridement using a papilla preservation technique. Defects were filled with DBBM and covered with CB. Clinical evidence after 6 months supported the effectiveness of the combination therapy in the treatment of intrabony defects.

  10. Molecular characterization of collagen IV evidences early transcription expression related to the immune response against bacterial infection in the red abalone (Haliotis rufescens).

    Science.gov (United States)

    Chovar-Vera, Ornella; Valenzuela-Muñoz, Valentina; Gallardo-Escárate, Cristian

    2015-02-01

    Collagen IV has been described as a structural protein of the basement membrane, which as a whole forms a specialized extracellular matrix. Recent studies have indicated a possible relationship between collagen IV and the innate immune response of invertebrate organisms. The present study characterized the alpha-1 chain of collagen IV in the red abalone Haliotis rufescens (Hr-ColIV) and evaluated its association with the innate immune response against Vibrio anguillarum. To further evidence the immune response, the matrix metalloproteinase-1 (Hr-MMP-1) and C-type lectin (Hr-CLEC) genes were also assessed. The complete sequence of Hr-ColIV was composed of 6658 bp, with a 5'UTR of 154 bp, a 3'UTR of 1177 bp, and an ORF of 5327 bp that coded for 1776 amino acids. The innate immune response generated against V. anguillarum resulted in a significant increase in the transcript levels of Hr-ColIV between 3 and 6 hpi, whereas Hr-MMP-1 and Hr-CLEC had the highest transcript activity 6 and 12 hpi, respectively. The results obtained in this study propose a putative biological function for collagen IV involved in the early innate immune response of the red abalone H. rufescens. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Molecular and Genetic Analyses of Collagen Type IV Mutant Mouse Models of Spontaneous Intracerebral Hemorrhage Identify Mechanisms for Stroke Prevention.

    Science.gov (United States)

    Jeanne, Marion; Jorgensen, Jeff; Gould, Douglas B

    2015-05-05

    Collagen type IV alpha1 (COL4A1) and alpha2 (COL4A2) form heterotrimers critical for vascular basement membrane stability and function. Patients with COL4A1 or COL4A2 mutations suffer from diverse cerebrovascular diseases, including cerebral microbleeds, porencephaly, and fatal intracerebral hemorrhage (ICH). However, the pathogenic mechanisms remain unknown, and there is a lack of effective treatment. Using Col4a1 and Col4a2 mutant mouse models, we investigated the genetic complexity and cellular mechanisms underlying the disease. We found that Col4a1 mutations cause abnormal vascular development, which triggers small-vessel disease, recurrent hemorrhagic strokes, and age-related macroangiopathy. We showed that allelic heterogeneity, genetic context, and environmental factors such as intense exercise or anticoagulant medication modulated disease severity and contributed to phenotypic heterogeneity. We found that intracellular accumulation of mutant collagen in vascular endothelial cells and pericytes was a key triggering factor of ICH. Finally, we showed that treatment of mutant mice with a US Food and Drug Administration-approved chemical chaperone resulted in a decreased collagen intracellular accumulation and a significant reduction in ICH severity. Our data are the first to show therapeutic prevention in vivo of ICH resulting from Col4a1 mutation and imply that a mechanism-based therapy promoting protein folding might also prevent ICH in patients with COL4A1 and COL4A2 mutations. © 2015 American Heart Association, Inc.

  12. Piezoelectric Collagen Hydrogels

    Indian Academy of Sciences (India)

    ... Collagen Hydrogels. Stress-induced potential in bone is produced by shear piezoelectricity in collagen fibers and streaming potential in canaliculae. The growth of bone is regulated to best resist external force. Piezo electrical property of collagen has come to be gainfully manipulated in collagen based biomaterial devices.

  13. Engineering multi-layered skeletal muscle tissue by using 3D microgrooved collagen scaffolds.

    Science.gov (United States)

    Chen, Shangwu; Nakamoto, Tomoko; Kawazoe, Naoki; Chen, Guoping

    2015-12-01

    Preparation of three-dimensional (3D) micropatterned porous scaffolds remains a great challenge for engineering of highly organized tissues such as skeletal muscle tissue and cardiac tissue. Two-dimensional (2D) micropatterned surfaces with periodic features (several nanometers to less than 100 μm) are commonly used to guide the alignment of muscle myoblasts and myotubes and lead to formation of pre-patterned cell sheets. However, cell sheets from 2D patterned surfaces have limited thickness, and harvesting the cell sheets for implantation is inconvenient and can lead to less alignment of myotubes. 3D micropatterned scaffolds can promote cell alignment and muscle tissue formation. In this study, we developed a novel type of 3D porous collagen scaffolds with concave microgrooves that mimic muscle basement membrane to engineer skeletal muscle tissue. Highly aligned and multi-layered muscle bundle tissues were engineered by controlling the size of microgrooves and cell seeding concentration. Myoblasts in the engineered muscle tissue were well-aligned and had high expression of myosin heavy chain and synthesis of muscle extracellular matrix. The microgrooved collagen scaffolds could be used to engineer organized multi-layered muscle tissue for implantation to repair/restore the function of diseased tissues or be used to investigate the cell-cell interaction in 3D microscale topography. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Clinical evaluation of porous hydroxyapatite bone graft (Periobone G with and without collagen membrane (Periocol in the treatment of bilateral grade II furcation defects in mandibular first permanent molars

    Directory of Open Access Journals (Sweden)

    Sruthy Prathap

    2013-01-01

    Full Text Available Background: Furcation invasions represent one of the most demanding therapeutic challenges in periodontics. This investigation assessed and compared the clinical efficacy of hydroxyapatite bone graft material when used alone and with collagen membrane in the treatment of grade II furcation defects. Materials and Methods: Ten patients with comparable bilateral furcation defects in relation to mandibular first molars were selected and treated in a split-mouth design. After the hygiene phase of therapy was completed, the groups were selected randomly either for treatment with hydroxyapatite bone graft (Periobone G alone or with a combination of bone graft and guided tissue regeneration (GTR membrane (Periocol. Clinical parameters like plaque index, gingival index, vertical probing depth, horizontal probing depth, clinical attachment level, position of marginal gingiva, and the amount of bone fill were used at baseline and at 3 and 6 months postoperatively. Results: At 6 months, both surgical procedures resulted in statistically significant reduction in vertical and horizontal probing depths and gain in the clinical attachment level. Conclusion: The use of combination technique yielded superior results compared to sites treated with bone graft alone. However, the difference was not statistically significant.

  15. Slow Muscle Precursors Lay Down a Collagen XV Matrix Fingerprint to Guide Motor Axon Navigation.

    Science.gov (United States)

    Guillon, Emilie; Bretaud, Sandrine; Ruggiero, Florence

    2016-03-02

    The extracellular matrix (ECM) provides local positional information to guide motoneuron axons toward their muscle target. Collagen XV is a basement membrane component mainly expressed in skeletal muscle. We have identified two zebrafish paralogs of the human COL15A1 gene, col15a1a and col15a1b, which display distinct expression patterns. Here we show that col15a1b is expressed and deposited in the motor path ECM by slow muscle precursors also called adaxial cells. We further demonstrate that collagen XV-B deposition is both temporally and spatially regulated before motor axon extension from the spinal cord in such a way that it remains in this region after the adaxial cells have migrated toward the periphery of the myotome. Loss- and gain-of-function experiments in zebrafish embryos demonstrate that col15a1b expression and subsequent collagen XV-B deposition and organization in the motor path ECM depend on a previously undescribed two-step mechanism involving Hedgehog/Gli and unplugged/MuSK signaling pathways. In silico analysis predicts a putative Gli binding site in the col15a1b proximal promoter. Using col15a1b promoter-reporter constructs, we demonstrate that col15a1b participates in the slow muscle genetic program as a direct target of Hedgehog/Gli signaling. Loss and gain of col15a1b function provoke pathfinding errors in primary and secondary motoneuron axons both at and beyond the choice point where axon pathway selection takes place. These defects result in muscle atrophy and compromised swimming behavior, a phenotype partially rescued by injection of a smyhc1:col15a1b construct. These reveal an unexpected and novel role for collagen XV in motor axon pathfinding and neuromuscular development. In addition to the archetypal axon guidance cues, the extracellular matrix provides local information that guides motor axons from the spinal cord to their muscle targets. Many of the proteins involved are unknown. Using the zebrafish model, we identified an

  16. Collagen vascular disease

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001223.htm Collagen vascular disease To use the sharing features on ... were previously said to have "connective tissue" or "collagen vascular" disease. We now have names for many ...

  17. Biochemical and biophysical characterization of collagens of marine sponge, Ircinia fusca (Porifera: Demospongiae: Irciniidae).

    Science.gov (United States)

    Pallela, Ramjee; Bojja, Sreedhar; Janapala, Venkateswara Rao

    2011-07-01

    Collagens were isolated and partially characterized from the marine demosponge, Ircinia fusca from Gulf of Mannar (GoM), India, with an aim to develop potentially applicable collagens from unused and under-used resources. The yield of insoluble, salt soluble and acid soluble forms of collagens was 31.71 ± 1.59, 20.69 ± 1.03, and 17.38 ± 0.87 mg/g dry weight, respectively. Trichrome staining, Scanning & Transmission Electron microscopic (SEM & TEM) studies confirmed the presence of collagen in the isolated, terminally globular irciniid filaments. The partially purified (gel filtration chromatography), non-fibrillar collagens appeared as basement type collagenous sheets under light microscopy whereas the purified fibrillar collagens appeared as fibrils with a repeated band periodicity of 67 nm under Atomic Force Microscope (AFM). The non-fibrillar and fibrillar collagens were seen to have affinity for anti-collagen type IV and type I antibodies raised against human collagens, respectively. The macromolecules, i.e., total protein, carbohydrate and lipid contents within the tissues were also quantified. The present information on the three characteristic irciniid collagens (filamentous, fibrillar and non-fibrillar) could assist the future attempts to unravel the therapeutically important, safer collagens from marine sponges for their use in pharmaceutical and cosmeceutical industries. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Clinical outcome of periodontal regenerative therapy using collagen membrane and deproteinized bovine bone mineral: a 2.5-year follow-up study.

    Science.gov (United States)

    Irokawa, Daisuke; Takeuchi, Takahiro; Noda, Katsuya; Goto, Hiroaki; Egawa, Masahiro; Tomita, Sachiyo; Sugito, Hiroki; Nikaido, Masahiko; Saito, Atsushi

    2017-02-17

    This study aimed to evaluate, longitudinally, the outcome of periodontal regenerative therapy using a deproteinized bovine bone mineral (DBBM) in combination with a collagen barrier (CB) for the treatment of intrabony defects. Patients with chronic periodontitis who have completed initial periodontal therapy participated in this study. They had at least one 2- or 3-wall intrabony periodontal defect of ≥3 mm in depth. During surgery, defects were filled with DBBM and covered with CB. Ten patients completed 2.5-year reevaluation. At baseline, mean clinical attachment level (CAL) of the treated site was 8.0 mm and mean probing depth (PD) was 7.5 mm. Mean depth of intrabony component was 4.6 mm. Mean gains in CAL at 6 months and 2.5 years were 2.8 ± 1.0 and 1.4 ± 1.5 mm, respectively, both showing a significant improvement from baseline. CAL gains at 1 and 2.5 years were significantly reduced from that at 6 months. A significant improvement in PD was also noted: mean reductions in PD at 6 months and 2.5 years were 4.0 ± 0.8 and 3.2 ± 0.8 mm, respectively. The combination therapy using DBBM and CB yielded statistically significant effects such as CAL gain and PD reduction, up to 2.5 years in the treatment of intrabony defects. However, the trend for decrease in CAL gain over time calls for the need for careful maintenance care.

  19. Fabrication and characterization of chitosan nanoparticles and collagen-loaded polyurethane nanocomposite membrane coated with heparin for atrial septal defect (ASD) closure.

    Science.gov (United States)

    Kaiser, Eva; Jaganathan, Saravana Kumar; Supriyanto, Eko; Ayyar, Manikandan

    2017-07-01

    Atrial septal defect (ASD) constitutes 30-40% of all congenital heart diseases in adults. The most common complications in the treatment of ASD are embolization of the device and thrombosis formation. In this research, an occluding patch was developed for ASD treatment using a well-known textile technology called electrospinning. For the first time, a cardiovascular occluding patch was fabricated using medical grade polyurethane (PU) loaded with bioactive agents namely chitosan nanoparticles (Cn) and collagen (Co) which is then coated with heparin (Hp). Fourier transform infrared spectrum showed characteristic vibrations of several active constituents and changes in the absorbance due to the inclusion of active ingredients in the patch. The contact angle analysis demonstrated no significant decrease in contact angle compared to the control and the composite patches. The structure of the electrospun nanocomposite (PUCnCoHp) was examined through scanning electron microscopy. A decrease in nanofiber diameter between control PU and PUCnCoHp nanocomposite was observed. Water uptake was found to be decreased for the PUCnCoHp nanocomposite against the control. The hemocompatibility properties of the PUCnCoHp ASD occluding patch was inferred through in vitro hemocompatibility tests like activated partial thromboplastin time (APTT), prothrombin time (PT) and hemolysis assay. It was found that the PT and APTT time was significantly prolonged for the fabricated PUCnCoHp ASD occluding patch compared to the control. Likewise, the hemolysis percentage was also decreased for the PUCnCoHp ASD patch against the control. In conclusion, the developed PUCnCoHp patch demonstrates potential properties to be used for ASD occlusion.

  20. Deformation and fracture of echinoderm collagen networks.

    Science.gov (United States)

    Ovaska, Markus; Bertalan, Zsolt; Miksic, Amandine; Sugni, Michela; Di Benedetto, Cristiano; Ferrario, Cinzia; Leggio, Livio; Guidetti, Luca; Alava, Mikko J; La Porta, Caterina A M; Zapperi, Stefano

    2017-01-01

    Collagen networks provide the main structural component of most tissues and represent an important ingredient for bio-mimetic materials for bio-medical applications. Here we study the mechanical properties of stiff collagen networks derived from three different echinoderms and show that they exhibit non-linear stiffening followed by brittle fracture. The disordered nature of the network leads to strong sample-to-sample fluctuations in elasticity and fracture strength. We perform numerical simulations of a three dimensional model for the deformation of a cross-linked elastic fibril network which is able to reproduce the macroscopic features of the experimental results and provide insights into the internal mechanics of stiff collagen networks. Our numerical model provides an avenue for the design of collagen membranes with tunable mechanical properties. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. A Simple Alkaline Method for Decellularizing Human Amniotic Membrane for Cell Culture

    Science.gov (United States)

    Saghizadeh, Mehrnoosh; Winkler, Michael A.; Kramerov, Andrei A.; Hemmati, David M.; Ghiam, Chantelle A.; Dimitrijevich, Slobodan D.; Sareen, Dhruv; Ornelas, Loren; Ghiasi, Homayon; Brunken, William J.; Maguen, Ezra; Rabinowitz, Yaron S.; Svendsen, Clive N.; Jirsova, Katerina; Ljubimov, Alexander V.

    2013-01-01

    Human amniotic membrane is a standard substratum used to culture limbal epithelial stem cells for transplantation to patients with limbal stem cell deficiency. Various methods were developed to decellularize amniotic membrane, because denuded membrane is poorly immunogenic and better supports repopulation by dissociated limbal epithelial cells. Amniotic membrane denuding usually involves treatment with EDTA and/or proteolytic enzymes; in many cases additional mechanical scraping is required. Although ensuring limbal cell proliferation, these methods are not standardized, require relatively long treatment times and can result in membrane damage. We propose to use 0.5 M NaOH to reliably remove amniotic cells from the membrane. This method was used before to lyse cells for DNA isolation and radioactivity counting. Gently rubbing a cotton swab soaked in NaOH over the epithelial side of amniotic membrane leads to nearly complete and easy removal of adherent cells in less than a minute. The denuded membrane is subsequently washed in a neutral buffer. Cell removal was more thorough and uniform than with EDTA, or EDTA plus mechanical scraping with an electric toothbrush, or n-heptanol plus EDTA treatment. NaOH-denuded amniotic membrane did not show any perforations compared with mechanical or thermolysin denuding, and showed excellent preservation of immunoreactivity for major basement membrane components including laminin α2, γ1-γ3 chains, α1/α2 and α6 type IV collagen chains, fibronectin, nidogen-2, and perlecan. Sodium hydroxide treatment was efficient with fresh or cryopreserved (10% dimethyl sulfoxide or 50% glycerol) amniotic membrane. The latter method is a common way of membrane storage for subsequent grafting in the European Union. NaOH-denuded amniotic membrane supported growth of human limbal epithelial cells, immortalized corneal epithelial cells, and induced pluripotent stem cells. This simple, fast and reliable method can be used to standardize

  2. A simple alkaline method for decellularizing human amniotic membrane for cell culture.

    Directory of Open Access Journals (Sweden)

    Mehrnoosh Saghizadeh

    Full Text Available Human amniotic membrane is a standard substratum used to culture limbal epithelial stem cells for transplantation to patients with limbal stem cell deficiency. Various methods were developed to decellularize amniotic membrane, because denuded membrane is poorly immunogenic and better supports repopulation by dissociated limbal epithelial cells. Amniotic membrane denuding usually involves treatment with EDTA and/or proteolytic enzymes; in many cases additional mechanical scraping is required. Although ensuring limbal cell proliferation, these methods are not standardized, require relatively long treatment times and can result in membrane damage. We propose to use 0.5 M NaOH to reliably remove amniotic cells from the membrane. This method was used before to lyse cells for DNA isolation and radioactivity counting. Gently rubbing a cotton swab soaked in NaOH over the epithelial side of amniotic membrane leads to nearly complete and easy removal of adherent cells in less than a minute. The denuded membrane is subsequently washed in a neutral buffer. Cell removal was more thorough and uniform than with EDTA, or EDTA plus mechanical scraping with an electric toothbrush, or n-heptanol plus EDTA treatment. NaOH-denuded amniotic membrane did not show any perforations compared with mechanical or thermolysin denuding, and showed excellent preservation of immunoreactivity for major basement membrane components including laminin α2, γ1-γ3 chains, α1/α2 and α6 type IV collagen chains, fibronectin, nidogen-2, and perlecan. Sodium hydroxide treatment was efficient with fresh or cryopreserved (10% dimethyl sulfoxide or 50% glycerol amniotic membrane. The latter method is a common way of membrane storage for subsequent grafting in the European Union. NaOH-denuded amniotic membrane supported growth of human limbal epithelial cells, immortalized corneal epithelial cells, and induced pluripotent stem cells. This simple, fast and reliable method can be used to

  3. Effects of Bronchial Thermoplasty on Airway Smooth Muscle and Collagen Deposition in Asthma.

    Science.gov (United States)

    Chakir, Jamila; Haj-Salem, Ikhlass; Gras, Delphine; Joubert, Philippe; Beaudoin, Ève-Léa; Biardel, Sabrina; Lampron, Noel; Martel, Simon; Chanez, Pascal; Boulet, Louis-Philippe; Laviolette, Michel

    2015-11-01

    The aim of bronchial thermoplasty is to improve asthma symptoms by reducing central airway smooth muscle mass. Up to now, the reduction of smooth muscle mass has been documented for only 1 group of 10 patients who had 15% or more of their pretreatment total bronchial biopsy area occupied by smooth muscle. To evaluate the effects of bronchial thermoplasty on airway smooth muscle mass and airway collagen deposition in adult patients with asthma, regardless of pretreatment smooth muscle area. Seventeen patients with asthma underwent bronchial thermoplasty over the course of three visits. At Visit 1, bronchial biopsies were taken from the lower lobe that was not treated during this session. At Visit 2 (3-14 wk after the first visit), all 17 patients underwent biopsy of the lower lobe treated during the first procedure. At Visit 3 (7-22 wk after the first visit), nine patients agreed to undergo biopsy of the same lower lobe. Histological and immunohistochemical analyses were performed on the biopsy specimens. Bronchial thermoplasty decreased airway smooth muscle from 12.9 ± 1.2% of the total biopsy surface at Visit 1 to 4.6 ± 0.8% at Visit 2 (P Bronchial thermoplasty also decreased Type I collagen deposition underneath the basement membrane from 6.8 ± 0.3 μm at Visit 1 to 4.3 ± 0.2 μm at Visit 2 (P bronchial thermoplasty reduced the smooth muscle mass of treated airway segments, regardless of the baseline level of muscle mass. Treatment also altered the deposition of collagen. At follow-up, bronchial thermoplasty improved asthma control; however, the limited number of subjects did not allow us to evaluate possible correlations between these improvements and the studied histological parameters. Further studies are needed to confirm these results and evaluate their persistence.

  4. Evaluation of biodegradation and biocompatibility of collagen ...

    Indian Academy of Sciences (India)

    The aim of this study was to develop a new variant of membranes based on collagen (COL), chitosan (CHI) and alkaline phosphatase (ALP) immobilized and cross-linking with glutaraldehyde (GA) at different concentrations. The biodegradation in the presence of collagenase was investigated. Biocompatibility was ...

  5. Does Alport syndrome affect the basement membrane of peritoneal vessels?

    NARCIS (Netherlands)

    Sampimon, Denise E.; Vlijm, Anniek; Struijk, Dirk G.; Krediet, Raymond T.

    2010-01-01

    Alport syndrome and encapsulating peritoneal sclerosis (EPS) are both rare diseases. Their joint occurrence is highly unlikely. Two patients at our center with Alport syndrome developed EPS. We therefore hypothesized that Alport syndrome might predispose to the development of EPS and that this

  6. Endocytic collagen degradation

    DEFF Research Database (Denmark)

    Madsen, Daniel H.; Jürgensen, Henrik J.; Ingvarsen, Signe Ziir

    2012-01-01

    Fibrosis of the liver and its end-stage, cirrhosis, represent major health problems worldwide. In these fibrotic conditions, activated fibroblasts and hepatic stellate cells display a net deposition of collagen. This collagen deposition is a major factor leading to liver dysfunction, thus making...... it crucially important to understand both the collagen synthesis and turnover mechanisms in this condition. Here we show that the endocytic collagen receptor, uPARAP/Endo180, is a major determinant in governing the balance between collagen deposition and degradation. Cirrhotic human livers displayed a marked...... importance of this collagen receptor in vivo, liver fibrosis was induced in uPARAP/Endo180-deficient mice and littermate wild-type mice by chronic CCl(4) administration. A strong up-regulation of uPARAP/Endo180 was observed in wild-type mice, and a quantitative comparison of collagen deposits in the two...

  7. The collagen receptor uPARAP/Endo180

    DEFF Research Database (Denmark)

    Engelholm, Lars H; Ingvarsen, Signe; Jürgensen, Henrik J

    2009-01-01

    The uPAR-associated protein (uPARAP/Endo180), a type-1 membrane protein belonging to the mannose receptor family, is an endocytic receptor for collagen. Through this endocytic function, the protein takes part in a previously unrecognized mechanism of collagen turnover. uPARAP/Endo180 can bind...... and internalize both intact and partially degraded collagens. In some turnover pathways, the function of the receptor probably involves an interplay with certain matrix-degrading proteases whereas, in other physiological processes, redundant mechanisms involving both endocytic and pericellular collagenolysis seem...... in collagen breakdown seems to be involved in invasive tumor growth Udgivelsesdato: 2009...

  8. Immuno-localization of type-IV collagen in the blood-gas barrier and the epithelial-epithelial cell connections of the avian lung.

    Science.gov (United States)

    Jimoh, S A; Maina, J N

    2013-02-23

    The terminal respiratory units of the gas exchange tissue of the avian lung, the air capillaries (ACs) and the blood capillaries (BCs), are small and rigid: the basis of this mechanical feature has been highly contentious. Because the strength of the blood-gas barrier (BGB) of the mammalian lung has been attributed to the presence of type-IV collagen (T-IVc), localization of T-IVc in the basement membranes (BM) of the BGB and the epithelial-epithelial cell connections (E-ECCs) of the exchange tissue of the lung of the avian (chicken) lung was performed in order to determine whether it may likewise contribute to the strength of the BGB. T-IVc was localized in both the BM and the E-ECCs. As part of an integrated fibroskeletal scaffold on the lung, T-IVc may directly contribute to the strengths of the ACs and the BCs.

  9. Immuno-localization of type-IV collagen in the blood-gas barrier and the epithelial–epithelial cell connections of the avian lung

    Science.gov (United States)

    Jimoh, S. A.; Maina, J. N.

    2013-01-01

    The terminal respiratory units of the gas exchange tissue of the avian lung, the air capillaries (ACs) and the blood capillaries (BCs), are small and rigid: the basis of this mechanical feature has been highly contentious. Because the strength of the blood-gas barrier (BGB) of the mammalian lung has been attributed to the presence of type-IV collagen (T-IVc), localization of T-IVc in the basement membranes (BM) of the BGB and the epithelial–epithelial cell connections (E-ECCs) of the exchange tissue of the lung of the avian (chicken) lung was performed in order to determine whether it may likewise contribute to the strength of the BGB. T-IVc was localized in both the BM and the E-ECCs. As part of an integrated fibroskeletal scaffold on the lung, T-IVc may directly contribute to the strengths of the ACs and the BCs. PMID:23193049

  10. Basement Construction of Measurement Standardization for Thermal Property and Basement Preparation of Industrial Technology

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kweon Ho; Song, Kee Chan; Park, Chang Je

    2007-02-15

    There are three main categories in this report : 1)Basement construction of measurement standardization for nuclear material thermal property, 2) Reliability evaluation of measurement instrument, and 3) Standardization and industrial propagation.

  11. 4-Hydroxy-2-nonenal Alkylated and Peroxynitrite Nitrated Proteins Localize to the Fused Mitochondria in Malpighian Epithelial Cells of Type IV Collagen Drosophila Mutants

    Directory of Open Access Journals (Sweden)

    András A. Kiss

    2018-01-01

    Full Text Available Background. Human type IV collagenopathy is associated with mutations within the COL4A1 and to a less extent the COL4A2 genes. The proteins encoded by these genes form heterotrimers and are the highest molar ratio components of the ubiquitous basement membrane. The clinical manifestations of the COL4A1/A2 mutations are systemic affecting many tissues and organs among these kidneys. In order to uncover the cellular and biochemical alterations associated with aberrant type IV collagen, we have explored the phenotype of the Malpighian tubules, the secretory organ and insect kidney model, in col4a1 collagen gene mutants of the fruit fly Drosophila melanogaster. In Malpighian epithelial cells of col4a1 mutants, robust mitochondrial fusion indicated mutation-induced stress. Immunohistochemistry detected proteins nitrated by peroxynitrite that localized to the enlarged mitochondria and increased level of membrane peroxidation, assessed by the amount of proteins alkylated by 4-hydroxy-2-nonenal that similarly localized to the fused mitochondria. Nuclei within the Malpighian epithelium showed TUNEL-positivity suggesting cell degradation. The results demonstrated that col4a1 mutations affect the epithelia and, consequently, secretory function of the Malpighian tubules and provide mechanistic insight into col4a1 mutation-associated functional impairments not yet reported in human patients and in mouse models with mutant COL4A1.

  12. Proximal collagenous gastroenteritides:

    DEFF Research Database (Denmark)

    Nielsen, Ole Haagen; Riis, Lene Buhl; Danese, Silvio

    2014-01-01

    AIM: While collagenous colitis represents the most common form of the collagenous gastroenteritides, the collagenous entities affecting the proximal part of the gastrointestinal tract are much less recognized and possibly overlooked. The aim was to summarize the latest information through...... a systematic review of collagenous gastritis, collagenous sprue, and a combination thereof. METHOD: The search yielded 117 studies which were suitable for inclusion in the systematic review. Excluding repeated cases, 89 case reports and 28 case series were reported, whereas no prospective studies...... with or without control groups were identified. Further, no randomized, controlled trials were identified. The total number of patients with proximal collagenous gastroenteritides reported was 330. RESULTS: An overview of clinical presentations, prognosis, pathophysiology and histopathology, as well as management...

  13. Structural and Geophysical Characterization of Oklahoma Basement

    Science.gov (United States)

    Morgan, C.; Johnston, C. S.; Carpenter, B. M.; Reches, Z.

    2017-12-01

    Oklahoma has experienced a large increase in seismicity since 2009 that has been attributed to wastewater injection. Most earthquakes, including four M5+ earthquakes, nucleated at depths > 4 km, well within the pre-Cambrian crystalline basement, even though wastewater injection occurred almost exclusively in the sedimentary sequence above. To better understand the structural characteristics of the rhyolite and granite that makeup the midcontinent basement, we analyzed a 150 m long core recovered from a basement borehole (Shads 4) in Rogers County, NE Oklahoma. The analysis of the fracture network in the rhyolite core included measurements of fracture inclination, aperture, and density, the examination fracture surface features and fill minerology, as well as x-ray diffraction analysis of secondary mineralization. We also analyzed the highly fractured and faulted segments of the core with a portable gamma-ray detector, magnetometer, and rebound hammer. The preliminary analysis of the fractures within the rhyolite core showed: (1) Fracture density increasing with depth by a factor of 10, from 4 fractures/10m in the upper core segment to 40 fracture/10m at 150 m deeper. (2) The fractures are primarily sub-vertical, inclined 10-20° from the axis of the vertical core. (3) The secondary mineralization is dominated by calcite and epidote. (4) Fracture aperture ranges from 0.35 to 2.35mm based on the thickness of secondary filling. (5) About 8% of the examined fractures display slickenside striations. (6) Increases of elasticity (by rebound hammer) and gamma-ray emissions are systematically correlated with a decrease in magnetic susceptibility in core segments of high fracture density and/or faulting; this observation suggests diagenetic fracture re-mineralization.

  14. Membrane-type-3 matrix metalloproteinase (MT3-MMP functions as a matrix composition-dependent effector of melanoma cell invasion.

    Directory of Open Access Journals (Sweden)

    Olga Tatti

    Full Text Available In primary human melanoma, the membrane-type matrix metalloproteinase, MT3-MMP, is overexpressed in the most aggressive nodular-type tumors. Unlike MT1-MMP and MT2-MMP, which promote cell invasion through basement membranes and collagen type I-rich tissues, the function of MT3-MMP in tumor progression remains unclear. Here, we demonstrate that MT3-MMP inhibits MT1-MMP-driven melanoma cell invasion in three-dimensional collagen, while yielding an altered, yet MT1-MMP-dependent, form of expansive growth behavior that phenocopies the formation of nodular cell colonies. In melanoma cell lines originating from advanced primary or metastatic lesions, endogenous MT3-MMP expression was associated with limited collagen-invasive potential. In the cell lines with highest MT3-MMP expression relative to MT1-MMP, collagen-invasive activity was increased following stable MT3-MMP gene silencing. Consistently, MT3-MMP overexpression in cells derived from less advanced superficially spreading melanoma lesions, or in the MT3-MMP knockdown cells, reduced MT1-MMP-dependent collagen invasion. Rather than altering MT1-MMP transcription, MT3-MMP interacted with MT1-MMP in membrane complexes and reduced its cell surface expression. By contrast, as a potent fibrinolytic enzyme, MT3-MMP induced efficient invasion of the cells in fibrin, a provisional matrix component frequently found at tumor-host tissue interfaces and perivascular spaces of melanoma. Since MT3-MMP was significantly upregulated in biopsies of human melanoma metastases, these results identify MT3-MMP as a matrix-dependent modifier of the invasive tumor cell functions during melanoma progression.

  15. Characterization of three-dimensional cancer cell migration in mixed collagen-Matrigel scaffolds using microfluidics and image analysis.

    Directory of Open Access Journals (Sweden)

    María Anguiano

    Full Text Available Microfluidic devices are becoming mainstream tools to recapitulate in vitro the behavior of cells and tissues. In this study, we use microfluidic devices filled with hydrogels of mixed collagen-Matrigel composition to study the migration of lung cancer cells under different cancer invasion microenvironments. We present the design of the microfluidic device, characterize the hydrogels morphologically and mechanically and use quantitative image analysis to measure the migration of H1299 lung adenocarcinoma cancer cells in different experimental conditions. Our results show the plasticity of lung cancer cell migration, which turns from mesenchymal in collagen only matrices, to lobopodial in collagen-Matrigel matrices that approximate the interface between a disrupted basement membrane and the underlying connective tissue. Our quantification of migration speed confirms a biphasic role of Matrigel. At low concentration, Matrigel facilitates migration, most probably by providing a supportive and growth factor retaining environment. At high concentration, Matrigel slows down migration, possibly due excessive attachment. Finally, we show that antibody-based integrin blockade promotes a change in migration phenotype from mesenchymal or lobopodial to amoeboid and analyze the effect of this change in migration dynamics, in regards to the structure of the matrix. In summary, we describe and characterize a robust microfluidic platform and a set of software tools that can be used to study lung cancer cell migration under different microenvironments and experimental conditions. This platform could be used in future studies, thus benefitting from the advantages introduced by microfluidic devices: precise control of the environment, excellent optical properties, parallelization for high throughput studies and efficient use of therapeutic drugs.

  16. Reliability of residential basements as blast shelters

    International Nuclear Information System (INIS)

    Longinow, A.; Mohammadi, J.

    1983-01-01

    This paper describes an analysis method for predicting the probability of failure of a wood-framed basement when subjected to a static, uniformly distributed load. The analysis considers the primary failure modes of each framing member and determines the probability of failure for each mode acting alone. The failure probability of the system as a whole is then bounded. The upper bound is determined on the assumption that the failure modes are independent, while the lower bound is determined on the assumption that the failure modes are perfectly correlated. The analysis is described with reference to an example problem

  17. Design and synthesis of collagen mimetic peptide derivatives for studying triple helix assembly and collagen mimetic peptide-collagen binding interaction

    Science.gov (United States)

    Mo, Xiao

    2008-10-01

    region, one of the thermally unstable domains in the collagen molecule. The binding results at various temperatures were in good agreement with our hypothesis that CMP-collagen binding occurs through strand invasion reaction of the thermally unstable collagen domain. In addition, purple membrane (PM), a protein crystal patch from halobacteria cell membrane, was genetically engineered to display cysteine or histidine groups on the membrane surface with defined nanoscale symmetry. X-ray diffraction results showed that the engineered PM formed a stable 2D PM-like hexagonal crystal lattice (unit cell: 6.2 mm). We utilized the genetically engineered PM as a bio-template for inorganic nanoparticle nucleation and assembly. The specific functional groups (cysteine or histidine) on the surfaces of genetically engineered PMs exhibited designed reactivity for inorganic nanoparticles while promoting the formation of nanoscale 2D particle assembly.

  18. Transmembrane collagen XVII modulates integrin dependent keratinocyte migration via PI3K/Rac1 signaling.

    Directory of Open Access Journals (Sweden)

    Stefanie Löffek

    Full Text Available The hemidesmosomal transmembrane component collagen XVII (ColXVII plays an important role in the anchorage of the epidermis to the underlying basement membrane. However, this adhesion protein seems to be also involved in the regulation of keratinocyte migration, since its expression in these cells is strongly elevated during reepithelialization of acute wounds and in the invasive front of squamous cell carcinoma, while its absence in ColXVII-deficient keratinocytes leads to altered cell motility. Using a genetic model of murine Col17a1⁻/⁻ keratinocytes we elucidated ColXVII mediated signaling pathways in cell adhesion and migration. Col17a1⁻/⁻ keratinocytes exhibited increased spreading on laminin 332 and accelerated, but less directed cell motility. These effects were accompanied by increased expression of the integrin subunits β4 and β1. The migratory phenotype, as evidenced by formation of multiple unstable lamellipodia, was associated with enhanced phosphoinositide 3-kinase (PI3K activity. Dissection of the signaling pathway uncovered enhanced phosphorylation of the β4 integrin subunit and the focal adhesion kinase (FAK as activators of PI3K. This resulted in elevated Rac1 activity as a downstream consequence. These results provide mechanistic evidence that ColXVII coordinates keratinocyte adhesion and directed motility by interfering integrin dependent PI3K activation and by stabilizing lamellipodia at the leading edge of reepithelializing wounds and in invasive squamous cell carcinoma.

  19. Different assembly of type IV collagen on hydrophilic and hydrophobic substrata alters endothelial cells interaction

    Directory of Open Access Journals (Sweden)

    NM Coelho

    2010-06-01

    Full Text Available Considering the structural role of type IV collagen (Col IV in the assembly of the basement membrane (BM and the perspective of mimicking its organization for vascular tissue engineering purposes, we studied the adsorption pattern of this protein on model hydrophilic (clean glass and hydrophobic trichloro(octadecylsilane (ODS surfaces known to strongly affect the behavior of other matrix proteins. The amount of fluorescently labeled Col IV was quantified showing saturation of the surface for concentration of the adsorbing solution of about 50μg/ml, but with approximately twice more adsorbed protein on ODS. AFM studies revealed a fine – nearly single molecular size – network arrangement of Col IV on hydrophilic glass, which turns into a prominent and growing polygonal network consisting of molecular aggregates on hydrophobic ODS. The protein layer forms within minutes in a concentration-dependent manner. We further found that human umbilical vein endothelial cells (HUVEC attach less efficiently to the aggregated Col IV (on ODS, as judged by the significantly altered cell spreading, focal adhesions formation and the development of actin cytoskeleton. Conversely, the immunofluorescence studies for integrins revealed that the fine Col IV network formed on hydrophilic substrata is better recognized by the cells via both α1 and α2 heterodimers which support cellular interaction, apart from these on hydrophobic ODS where almost no clustering of integrins was observed.

  20. Magnetotelluric inversion for depth-to-basement estimation

    DEFF Research Database (Denmark)

    Cai, Hongzhu; Zhdanov, Michael

    2015-01-01

    The magnetotelluric (MT) method can be effectively applied for depth-to-basement estimation, because there exists a strong contrast in resistivity between a conductive sedimentary basin and a resistive crystalline basement. Conventional inversions of MT data are usually aimed at determining...... the volumetric distribution of the conductivity within the inversion domain. By the nature of the MT method, the recovered distribution of the subsurface conductivity is typically diffusive, which makes it difficult to select the sediment-basement interface. This paper develops a novel approach to 3D MT...... inversion for the depth-to-basement estimate. The key to this approach is selection of the model parameterization with the depth to basement being the major unknown parameter. In order to estimate the depth to the basement, the inversion algorithm recovers both the thickness and the conductivities...

  1. Geochemistry of the Puna Austral and Cordillera Oriental basement

    International Nuclear Information System (INIS)

    Becchio, Raul; Lucassen, Friedrich; Franz, Gerhard; Kasemann, Simone

    1998-01-01

    Major and trace elements, rare earths, and 143 Nd/ 147 Nd and, 147 Sm/ 144 Nd isotope ratios have been determined in the Puna Austral and Cordillera Oriental basement. The basement is formed by high temperature amphibolite facies rocks ranulites (750-550 degrees C) and green schists. They are represented by schists, paragneiss, orthogneiss, migmatites, few metabasites, marbles and chalcosilicatic banks. Hypotheses on the formation and evolution of the basement are presented

  2. Role of collagens and perlecan in microvascular stability: exploring the mechanism of capillary vessel damage by snake venom metalloproteinases.

    Directory of Open Access Journals (Sweden)

    Teresa Escalante

    Full Text Available Hemorrhage is a clinically important manifestation of viperid snakebite envenomings, and is induced by snake venom metalloproteinases (SVMPs. Hemorrhagic and non-hemorrhagic SVMPs hydrolyze some basement membrane (BM and associated extracellular matrix (ECM proteins. Nevertheless, only hemorrhagic SVMPs are able to disrupt microvessels; the mechanisms behind this functional difference remain largely unknown. We compared the proteolytic activity of the hemorrhagic P-I SVMP BaP1, from the venom of Bothrops asper, and the non-hemorrhagic P-I SVMP leucurolysin-a (leuc-a, from the venom of Bothrops leucurus, on several substrates in vitro and in vivo, focusing on BM proteins. When incubated with Matrigel, a soluble extract of BM, both enzymes hydrolyzed laminin, nidogen and perlecan, albeit BaP1 did it at a faster rate. Type IV collagen was readily digested by BaP1 while leuc-a only induced a slight hydrolysis. Degradation of BM proteins in vivo was studied in mouse gastrocnemius muscle. Western blot analysis of muscle tissue homogenates showed a similar degradation of laminin chains by both enzymes, whereas nidogen was cleaved to a higher extent by BaP1, and perlecan and type IV collagen were readily digested by BaP1 but not by leuc-a. Immunohistochemistry of muscle tissue samples showed a decrease in the immunostaining of type IV collagen after injection of BaP1, but not by leuc-a. Proteomic analysis by LC/MS/MS of exudates collected from injected muscle revealed higher amounts of perlecan, and types VI and XV collagens, in exudates from BaP1-injected tissue. The differences in the hemorrhagic activity of these SVMPs could be explained by their variable ability to degrade key BM and associated ECM substrates in vivo, particularly perlecan and several non-fibrillar collagens, which play a mechanical stabilizing role in microvessel structure. These results underscore the key role played by these ECM components in the mechanical stability of

  3. A urokinase receptor-associated protein with specific collagen binding properties

    DEFF Research Database (Denmark)

    Behrendt, N; Jensen, O N; Engelholm, L H

    2000-01-01

    membrane-bound lectin with hitherto unknown function. The human cDNA was cloned and sequenced. The protein, designated uPARAP, is a member of the macrophage mannose receptor protein family and contains a putative collagen-binding (fibronectin type II) domain in addition to 8 C-type carbohydrate recognition...... domains. It proved capable of binding strongly to a single type of collagen, collagen V. This collagen binding reaction at the exact site of plasminogen activation on the cell may lead to adhesive functions as well as a contribution to cellular degradation of collagen matrices....

  4. New skin-equivalent model from de-epithelialized amnion membrane.

    Science.gov (United States)

    Yang, Lujun; Shirakata, Yuji; Shudou, Masachika; Dai, Xiuju; Tokumaru, Sho; Hirakawa, Satoshi; Sayama, Koji; Hamuro, Junji; Hashimoto, Koji

    2006-10-01

    The presence of pre-existing basement membrane (BM) components improves the morphogenesis of epidermis and BM in constructing a human living skin-equivalent (LSE). De-epithelialized amniotic membrane (AM) retains key BM components. We have therefore investigated the usefulness of AM for constructing LSE. De-epithelialized AM was overlaid on type I collagen gel embedded with fibroblasts. Normal human keratinocytes (NHKs) were then seeded onto the epithelial side of the AM to construct an AM-LSE. A conventional LSE was constructed by seeding NHKs on a fibroblast-populated type I collagen gel. When the keratinocytes reached confluence, the LSE was lifted to the air-liquid interface and cultured for up to 3 weeks. Samples were harvested at various times and investigated morphologically, immunohistochemically, and ultrastructurally. In AM-LSE, the epidermis was better stratified, with more compact, polarized, columnar basal cells, and the expression of differentiation and proliferation markers was more similar to that of normal human skin than was that of LSE without AM. A more continuous BM and better-developed hemidesmosomes were found in AM-LSE. The epidermis of AM-LSE outgrew much faster than that of LSE without AM. When transplanted onto nude mice, both LSEs took well; however, the AM-LSE graft showed better morphogenesis of the epidermis, BM, and hemidesmosomes. The better epidermal morphology and better-developed BM in AM-LSE in vitro and in vivo indicates its superiority over LSE without AM for clinical applications.

  5. Depth-To-Basement Mapping Using Fractal Technique: Application ...

    African Journals Online (AJOL)

    ... and can thus be obtained at source level. Application to aeromagnetic data from the Chad basin north eastern Nigeria produced a basement relief which range from depths of 2.47 km to 5.40 km with an average of 3.92 +- 0.66 km. Keywords: Fractal, depth, basement, spectra, aeromagnetic. Nigerian Journal of Physics Vol ...

  6. Investigation of the subsurface features of the basement complex of ...

    African Journals Online (AJOL)

    3D seismic reflection survey was recently carried out within the Zaria area of the basement complex of northern Nigeria, in order to investigate the complexity of the subsurface features within the basement. The geology of the survey area was characterized by gneisses and low grade meta-sedimentary rocks that form the ...

  7. Potential Development of Hydrocarbon in Basement Reservoirs In Indonesia

    Directory of Open Access Journals (Sweden)

    D. Sunarjanto

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v8i3.165Basement rocks, in particular igneous and metamorphic rocks are known to have porosity and permeability which should not be ignored. Primary porosity of basement rocks occurs as the result of rock formation. The porosity increases by the presence of cracks occurring as the result of tectonic processes (secondary porosity. Various efforts have been carried out to explore hydrocarbon in basement rocks. Some oil and gas fields proved that the basement rocks are as reservoirs which so far have provided oil and gas in significant amount. A review using previous research data, new data, and observation of igneous rocks in some fields has been done to see the development of exploration and basement reservoirs in Indonesia. A review on terminology of basement rock up till the identification of oil and gas exploration in basement rocks need to be based on the latest technology. An environmental approach is suggested to be applied as an alternative in analyzing the policy on oil and gas exploration development, especially in basement reservoirs.

  8. Basement and alluvial aquifers of Malawi: An overview of ...

    African Journals Online (AJOL)

    This paper highlights the quality of groundwater in basement and alluvial aquifers of Malawi through literature assessment. Groundwater in these aquifers serves about 60% of Malawian population. Alluvial aquifers yield high groundwater in excess of 10 L/s and more mineralized than basement aquifers. The values from ...

  9. Estimation of Magnetic Basement Depth of Oyo Area from ...

    African Journals Online (AJOL)

    The digitized magnetic intensity data of Oyo area, south western Nigeria was analyzed to estimate depths to magnetic sources as well as source locations. The total magnetic intensity values ranges from -143.8 nT to 147.0 nT suggesting contrasting rock types in the basement complex. The magnetic basement depth results ...

  10. Evidence of basement controlled faulting of cretaceous strata in the ...

    African Journals Online (AJOL)

    Evidence of basement controlled faulting of cretaceous strata in the Middle Benue Trough, Nigeria from lineament analysis of gravity data. ... anomaly map of part of the Middle Benue Trough, Nigeria, was used to investigate the genetic relationship between the basement and intra-sedimentary structures in the study area.

  11. A biomimetic strategy to form calcium phosphate crystals on type I collagen substrate

    Energy Technology Data Exchange (ETDEWEB)

    Xu Zhang [Department of Restorative Dentistry, Faculty of Dentistry, National University of Singapore, 5 Lower Kent Ridge Road 119074, Singapore (Singapore); Neoh, Koon Gee [Department of Chemical and Biomolecular Engineering, National University of Singapore, Kent Ridge 119260, Singapore (Singapore); Kishen, Anil, E-mail: anil.kishen@utoronto.ca [Discipline of Endodontics, Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON (Canada)

    2010-07-20

    Objective: The aim of this study is to induce mineralization of collagen by introducing phosphate groups onto type I collagen from eggshell membrane (ESM) by treating with sodium trimetaphosphate (STMP). This strategy is based on the hypothesis that phosphate groups introduced on collagen can mimic the nucleating role of phosphorylated non-collagenous proteins bound to collagen for inducing mineralization in natural hard tissue. Method: The collagen membrane was phosphorylated by treating it with a solution of STMP and saturated calcium hydroxide. The phosphorylated collagen was subsequently exposed to a mineralization solution and the pattern of mineralization on the surface of phosphorylated collagen substrate was analyzed. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), field emission electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and microhardness test were used to characterize the collagen substrate and the pattern of minerals formed on the collagen surface. Results: The FTIR and EDX results indicated that the phosphate groups were incorporated onto the collagen surface by treatment with STMP. During the mineralization process, the plate-like mineral, octacalcium phosphate (OCP), which was initially formed on the surface of ESM, was later transformed into needle-like hydroxyapatite (HAP) as indicated by the SEM, FESEM, EDX and XRD findings. The microhardness test displayed significant increase in the Knoop hardness number of the mineralized collagen. Conclusions: Phosphate groups can be introduced onto type I collagen surface by treating it with STMP and such phosphorylated collagen can induce the mineralization of type I collagen.

  12. Corneal collagen crosslinking for keratoconus. A review

    Directory of Open Access Journals (Sweden)

    M. M. Bikbov

    2014-10-01

    Full Text Available Photochemical crosslinking is widely applied in ophthalmology. Its biochemical effect is due to the release of singlet oxygen that promotes anaerobic photochemical reaction. Keratoconus is one of the most common corneal ectasia affecting 1 in 250 to 250 000 persons. Currently, the rate of iatrogenic ectasia following eximer laser refractive surgery increases due to biomechanical weakening of the cornea. Morphologically and biochemically, ectasia is characterized by corneal layers thinning, contact between the stroma and epithelium resulting from Bowman’s membrane rupture, chromatin fragmentation in keratocyte nuclei, phagocytosis, abnormal staining and arrangement of collagen fibers, enzyme system disorders, and keratocyte apoptosis. In corneal ectasia, altered enzymatic processes result in the synthesis of abnormal collagen. Collagen packing is determined by the activity of various extracellular matrix enzymes which bind amines and aldehydes of collagen fiber amino acids. In the late stage, morphological changes of Descemet’s membrane (i.e., rupture and detachment develop. Abnormal hexagonal-shaped keratocytes and their apoptosis are the signs of endothelial dystrophy. The lack of analogs in domestic ophthalmology encouraged the scientists of Ufa Eye Research Institute to develop a device for corneal collagen crosslinking. The parameters of ultraviolet (i.e., wavelength, exposure time, power to achieve the desired effect were identified. The specifics of some photosensitizers in the course of the procedure were studied. UFalink, a device for UV irradiation of cornea, and photosensitizer Dextralink were developed and adopted. Due to the high risk of endothelial damage, this treatment is contraindicated in severe keratoconus (CCT less than 400 microns. Major effects of corneal collagen crosslinking are the following: Young’s modulus (modulus of elasticity increase by 328.9 % (on average, temperature tolerance increase by 5

  13. Possibilities of seismic exploration for crystalline basement study

    Directory of Open Access Journals (Sweden)

    А. Н. Телегин

    2017-03-01

    Full Text Available Possibilities of seismic methods of reflected and refracted waves have been examined for the purposes of detailed study on crystalline basement structure. Investigation of depth and structure of the basement plays an important role in the exploration of various deposits. Sedimentary cover is usually associated with oil and gas reserves. Ore deposits are formed in the basement rocks, basement splits and structure of its surface have a genetic relation not only to ore minerals, but also to oil resources. Reflection seismology is one of the main seismic methods of investigating structural geometry of the sedimentation mass, forecasting its material composition and possible hydrocarbon reserves. However, its possibilities for investigating crystalline basement are limited. Basing on many years’ experience of reflection seismology and physical modeling it has been identified that actual roughness of basement surface limits the obtainable amount of waves reflected from it. Possibilities of reflection seismology for basement structure study are mostly related to investigation of discontinuous faults as diffraction objects using diffracted waves. Method of refracted waves combined with modern procedures and material processing aimed at getting dynamic seismic sections holds much significance for the basement study, especially in the process of surface mapping and, to a lesser extent, in investigating discontinuous faults. Combining seismic methods of reflected and refracted waves in basement study increases reliability of forecasting its geological structure: in particular, its surface can be well defined by means of refraction seismology, and zones of discontinuous faults are identified from diffraction objects using both reflection and refraction methods. As a result of applying both reflection and refraction seismology, an opportunity arises to carry out detailed analysis of basement structure and to predict its oil and gas content.

  14. Collagen metabolism in obesity

    DEFF Research Database (Denmark)

    Rasmussen, M H; Jensen, L T; Andersen, T

    1995-01-01

    OBJECTIVE: To investigate the impact of obesity, fat distribution and weight loss on collagen turnover using serum concentrations of the carboxyterminal propeptide of type I procollagen (S-PICP) and the aminoterminal propeptide of type III pro-collagen (S-PIIINP) as markers for collagen turnover...... (r = 0.37; P = 0.004), height (r = 0.27; P = 0.04), waist circumference (r = 0.35; P = 0.007), as well as with WHR (r = 0.33; P = 0.01) and was inversely correlated to age (r = -0.40; P = 0.002). Compared with randomly selected controls from a large pool of healthy volunteers, the obese patients had...... restriction (P obesity and associated with body fat distribution, suggesting...

  15. Cancer risk in collagenous colitis

    NARCIS (Netherlands)

    Chan, J. L.; Tersmette, A. C.; Offerhaus, G. J.; Gruber, S. B.; Bayless, T. M.; Giardiello, F. M.

    1999-01-01

    Collagenous colitis is a recently described form of chronic inflammatory bowel disease. Other inflammatory bowel disorders are associated with increased risk of colorectal and extracolonic malignancies, but this has not been evaluated in collagenous colitis. Colorectal and extracolonic malignancies

  16. Modelling collagen diseases: STRUCTURAL BIOLOGY

    OpenAIRE

    Brodsky, Barbara; Baum, Jean

    2008-01-01

    Mutations in collagen lead to hereditary disorders such as brittle-bone disease. Peptide models for aberrant collagens are beginning to clarify how these amino-acid replacements lead to clinical problems.

  17. Collagen turnover after tibial fractures

    DEFF Research Database (Denmark)

    Joerring, S; Krogsgaard, M; Wilbek, H

    1994-01-01

    Collagen turnover after tibial fractures was examined in 16 patients with fracture of the tibial diaphysis and in 8 patients with fracture in the tibial condyle area by measuring sequential changes in serological markers of turnover of types I and III collagen for up to 26 weeks after fracture...... collagen. A group comparison showed characteristic sequential changes in the turnover of types I and III collagen in fractures of the tibial diaphysis and tibial condyles. The turnover of type III collagen reached a maximum after 2 weeks in both groups. The synthesis of type I collagen reached a maximum...... after 2 weeks in the diaphyseal fractures and after 6 weeks in the condylar fractures. The degradation of type I collagen increased after 4 days and reached a maximum at 2 weeks in both groups. The interindividual variation was wide. On a group basis, the turnover of types I and III collagen had...

  18. Collagen Homeostasis and Metabolism

    DEFF Research Database (Denmark)

    Magnusson, S Peter; Heinemeier, Katja M; Kjaer, Michael

    2016-01-01

    The musculoskeletal system and its collagen rich tissue is important for ensuring architecture of skeletal muscle, energy storage in tendon and ligaments, joint surface protection, and for ensuring the transfer of muscular forces into resulting limb movement. Structure of tendon is stable and the...

  19. Genetic disorders of collagen.

    OpenAIRE

    Tsipouras, P; Ramirez, F

    1987-01-01

    Osteogenesis imperfecta, Ehlers-Danlos syndrome, and Marfan syndrome form a group of genetic disorders of connective tissue. These disorders exhibit remarkable clinical heterogeneity which reflects their underlying biochemical and molecular differences. Defects in collagen types I and III have been found in all three syndromes.

  20. Rheology of Heterotypic Collagen Networks

    NARCIS (Netherlands)

    Piechocka, I.K.; van Oosten, A.S.G.; Breuls, R.G.M.; Koenderink, G.H.

    2011-01-01

    Collagen fibrils are the main structural element of connective tissues. In many tissues, these fibrils contain two fibrillar collagens (types I and V) in a ratio that changes during tissue development, regeneration, and various diseases. Here we investigate the influence of collagen composition on

  1. Collagen hydrolysate based collagen/hydroxyapatite composite materials

    Science.gov (United States)

    Ficai, Anton; Albu, Madalina Georgiana; Birsan, Mihaela; Sonmez, Maria; Ficai, Denisa; Trandafir, Viorica; Andronescu, Ecaterina

    2013-04-01

    The aim of this study was to study the influence of collagen hydrolysate (HAS) on the formation of ternary collagen-hydrolysate/hydroxyapatite composite materials (COLL-HAS/HA). During the precipitation process of HA, a large amount of brushite is resulted at pH = 7 but, practically pure HA is obtained at pH ⩾ 8. The FTIR data reveal the duplication of the most important collagen absorption bands due to the presence of the collagen hydrolysate. The presence of collagen hydrolysate is beneficial for the management of bone and joint disorders such as osteoarthritis and osteoporosis.

  2. Sodium fire in the ILONA basement

    International Nuclear Information System (INIS)

    Klemm, H.

    1993-05-01

    The report describes the reasons, the course, the fire fighting measures and the consequences of the sodium fire, which damaged severely the 5 MW sodium test facility ILONA in Bergisch-Gladbach, Germany, in 1990. The accident occurred in the process of transferring Na from one tank containing 0.5 m''3 Na into another one with 6 m''3 Na, which were connected via sodium and gas exchange pipes. The 6 m''3 tank was also fitted with a dipping-pipe for the later purpose of filling or evacuation. The pipe was closed by a plug. The two tanks were flooded with argon. The leakage with consequent Na fire started during the preheating process of the 6 m''3 tank, and later investigations showed that Na had leaked from the dipping-pipe after a too high pressure built-up. Whether that happened because of the failure of a pressure compensation valve or because of a blockage of the pipe connecting the two tanks, could not be clarified after the accident because of the damages caused by the fire. The later analysis showed that about 4500 kg out of the originally 5820 kg had leaked from the tank during a time of about 5 hours. A total of 1344 kg Na were deposited as combustion product aerosols (carbonate and bi-carbonate) in the building and about 930 kg Na were released from the building to the atmosphere. On the basis of the temperature difference between 400 deg C in the basement and 20 deg C at the outlet and a height difference of 30 m, the gas stream was estimated to 4 m''3 per sec. The aerosol clouds left the building via the natural draught stack. They were quickly transformed into carbonate and bi-carbonate, which do not represent a risk for the people, the animals or the vegetation in the surroundings

  3. Effects of sodium hyaluronate and carboxymethylcellulose membrane on collagen and fibroblast formation in bowel suture healing: experimental study in rats Efeitos da membrana de hialuronato de sódio e carboximetilcelulose na formação de colágeno e fibroblastos no processo de cicatrização de colorrafias: estudo experimental em ratos

    Directory of Open Access Journals (Sweden)

    Antônio Carlos Perez

    2005-02-01

    Full Text Available PURPOSE: To analyze the effects of sodium hyaluronate and carboxymethylcellulose membrane on collagen and fibroblast formation in bowel suture healing in rats. METHODS: 48 male Wistar rats, weighing 250 to 343g, were randomized into two groups: group I - bowel suture without applying a biologically absorbable membrane and group II - bowel suture with application of an absorbable membrane. The two groups were divided into subgroups of 3, 14 and 30 days of observation, with 8 rats in each subgroup. All were sacrificed after the end of the observation period. RESULTS: No morbidity or mortality was observed during the experiment. The amounts of collagen in group I were 23.4%, 72.1% and 67.6% and in group II were 22.5%, 52.5% and 51.6%, for the subgroups of 3, 14 and 30 days, respectively. Comparison between groups showed that the 14-day (p=0.0013 and 30-day (p=0.0587 subgroups had significant variance, with larger collagen zones in animals in which the membrane was not applied. However, with regard to fibroblasts, group I had 2%, 13% and 8% and group II had 2%, 10% and 8%, for the 3-day (p=1.0, 14-day (p=0.3184 and 30-day (p=0.5995 subgroups, respectively, showing no significant variance. CONCLUSION: The use of the biologically absorbable membrane cause a decrease in collagen formation, while not altering the number of fibroblasts, in bowel suture healing in rats, without increased morbidity and mortality.OBJETIVO: Analisar os efeitos da membrana de hialuronato de sódio e carboximetilcelulose, na formação de colágeno e fibroblastos na colorrafia de ratos. MÉTODOS: Foram utilizados 48 ratos machos da linhagem Wistar, com peso entre 250 e 343g, distribuídos em dois grupos: grupo I colorrafia sem aplicação de membrana bioabsorvível e grupo II colorrafia com aplicação de membrana bioabsorvível; tendo sido divididos em subgrupos de 3, 14 e 30 dias de observação, com 8 animais em cada um dos subgrupos, todos submetidos à eutanásia após o

  4. Prognostic value of glomerular collagen IV immunofluorescence studies in male patients with X-linked Alport syndrome.

    Science.gov (United States)

    Massella, Laura; Gangemi, Concetta; Giannakakis, Kostas; Crisafi, Antonella; Faraggiana, Tullio; Fallerini, Chiara; Renieri, Alessandra; Muda, Andrea Onetti; Emma, Francesco

    2013-05-01

    X-linked Alport syndrome (X-AS) is caused by mutations of the COL4A5 gene, which encodes for the collagen IV α5 chain (α5[COLIV]), resulting in structural and functional abnormalities of the glomerular basement membrane (GBM) and leading to CKD. The aim of the present study was to evaluate the prognostic value of residual collagen IV chain expression in the GBM of patients with X-AS. The medical records of 22 patients with X-AS from 21 unrelated families collected between 1987 and 2009 were reviewed (median age at last follow-up, 19.9 years; range, 5.4-35.1 years); GBM expression of α1, α3, and α5(COLIV) chains was assessed by immunofluorescence microscopy. GBM distribution of the α5(COLIV) chain was diffuse in 1 and segmental or absent in 21 of the 22 patients; the expression of the α3(COLIV) chain was diffuse in 5 of 22 patients and segmental or absent in 17 of 22 patients. Patients with diffuse staining for the α3(COLIV) chain presented with proteinuria significantly later (median age, 16.9 versus 6.1 years; P=0.02) and reached an estimated GFR < 90 ml/min per 1.73 m(2) at an older age (median age, 27.0 versus 14.9 years; P=0.01) compared with patients with segmental or absent staining. Two thirds of patients with abnormal α3(COLIV) expression by immunofluorescence studies had null or truncating COL4A5 mutations, as opposed to none of the 4 tested patients with diffuse α3(COLIV) chain glomerular distribution. These results indicate that maintained expression of the α3(COLIV) chain is an early positive prognostic marker in patients with X-linked Alport symdrome.

  5. Native type IV collagen induces an epithelial to mesenchymal transition-like process in mammary epithelial cells MCF10A.

    Science.gov (United States)

    Espinosa Neira, Roberto; Salazar, Eduardo Perez

    2012-12-01

    Basement membrane (BM) is a complex network of interacting proteins, including type IV collagen (Col IV) that acts as a scaffold that stabilizes the physical structures of tissues and regulates cellular processes. In the mammary gland, BM is a continuous deposit that separates epithelial cells from stroma, and its degradation is related with an increased potential for invasion and metastasis. Epithelial to mesenchymal transition (EMT) is a process by which epithelial cells are transdifferentiated to one mesenchymal state, and is a normal process during embryonic development, tissue remodeling and wound healing, as well as it has been implicated during cancer progression. In breast cancer cells, native Col IV induces migration and gelatinases secretion. However, the role of native Col IV on the EMT process in human mammary epithelial cells remains to be investigated. In the present study, we demonstrate that native Col IV induces down-regulation of E-cadherin expression, accompanied with an increase of Snail1, Snail2 and Sip1 transcripts. Native Col IV also induces an increase in N-cadherin and vimentin expression, an increase of MMP-2 secretion, the activation of FAK and NFκB, cell migration and invasion in MCF10A cells. In summary, these findings demonstrate, for the first time, that native Col IV induces an EMT-like process in MCF10A human mammary non-tumorigenic epithelial cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Building America Top Innovations 2012: Basement Insulation Systems

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-01-01

    This Building America Top Innovations profile describes research on basement insulation, which identifies the wall installation methods and materials that perform best in terms of insulation and water resistance.

  7. Groundwater Exploration in the Basement Complex Around Chibok ...

    African Journals Online (AJOL)

    admin

    ABSTRACT: A geophysical survey employing Schlumberger electrode configuration using vertical electrical sounding (VES) method ... Keywords: Hydrogeology, Basement Complex, Alluvium, Colluviums, Electric resistivity, Chibok. INTRODUCTION .... unconcentrated surface runoff or sheet erosion. It is not concentrated ...

  8. Basement configuration of KG offshore basin from magnetic anomalies

    Digital Repository Service at National Institute of Oceanography (India)

    Subrahmanyam, V.; Swamy, K.V.; Raj, N.

    basement is faulted along the NW-SE direction with the upthrown side lying to the north of the anomaly trend of this region. The coincidence of magnetizations observed through the present interpretation with that of charnockites of neighbouring EGMB...

  9. Collagen turnover after tibial fractures

    DEFF Research Database (Denmark)

    Joerring, S; Krogsgaard, M; Wilbek, H

    1994-01-01

    Collagen turnover after tibial fractures was examined in 16 patients with fracture of the tibial diaphysis and in 8 patients with fracture in the tibial condyle area by measuring sequential changes in serological markers of turnover of types I and III collagen for up to 26 weeks after fracture....... The markers were the carboxy-terminal extension peptide of type I procollagen (PICP), the amino-terminal extension peptide of type III procollagen (PIIINP), and the pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen (ICTP). The latter is a new serum marker of degradation of type I...... collagen. A group comparison showed characteristic sequential changes in the turnover of types I and III collagen in fractures of the tibial diaphysis and tibial condyles. The turnover of type III collagen reached a maximum after 2 weeks in both groups. The synthesis of type I collagen reached a maximum...

  10. Frictional Behavior of Altered Basement Approaching the Nankai Trough

    Science.gov (United States)

    Saffer, D. M.; Ikari, M.; Rooney, T. O.; Marone, C.

    2017-12-01

    The frictional behavior of basement rocks plays an important role in subduction zone faulting and seismicity. This includes earthquakes seaward of the trench, large megathrust earthquakes where seamounts are subducting, or where the plate interface steps down to basement. In exhumed subduction zone rocks such as the Shimanto complex in Japan, slivers of basalt are entrained in mélange which is evidence of basement involvement in the fault system. Scientific drilling during the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) recovered basement rock from two reference sites (C0011 and C0012) located seaward of the trench offshore the Kii Peninsula during Integrated Ocean Discovery Program (IODP) Expeditions 322 and 333. The basement rocks are pillow basalts that appear to be heterogeneously altered, resulting in contrasting dense blue material and more vesicular gray material. Major element geochemistry shows differences in silica, calcium oxides and loss-on-ignition between the two types of samples. Minor element geochemistry reveals significant differences in vanadium, chromium, and barium. X-ray diffraction on a bulk sample powder representing an average composition shows a phyllosilicate content of 20%, most of which is expandable clays. We performed laboratory friction experiments in a biaxial testing apparatus as either intact sample blocks, or as gouge powders. We combine these experiments with measurements of Pennsylvania slate for comparison, including a mixed-lithology intact block experiment. Intact Nankai basement blocks exhibit a coefficient of sliding friction of 0.73; for Nankai basement powder, slate powder, slate blocks and slate-on-basement blocks the coefficient of sliding friction ranges from 0.44 to 0.57. At slip rates ranging from 3x10-8 to 3x10-4 m/s we observe predominantly velocity-strengthening frictional behavior, indicating a tendency for stable slip. At rates of < 1x10-6 m/s some velocity-weakening was observed, specifically in

  11. Basement Fault Reactivation by Fluid Injection into Sedimentary Reservoirs

    Science.gov (United States)

    Peter, Eichhubl; Fan, Zhiqiang; Zhu, Cheng

    2017-04-01

    Many suspected injection-induced earthquakes occur in crystalline basement rather than in the overlying sedimentary injection reservoir. To address why earthquakes nucleate in the basement rather than the injection layer we investigate the relationship between pore pressure diffusion, rock matrix deformation, and induced fault reactivation through 3D fully coupled poroelastic finite element models. These models simulate the temporal and spatial perturbation of pore pressure and solid stresses within a basement fault that extends into overlying sedimentary layers and that is conductive for flow along the fault but a barrier for flow across. We compare the effects of direct pore pressure communication and indirect poroelastic stress transfer from the injection reservoir to the fault on increasing the Coulomb failure stress that could reactivate the basement fault for normal, reverse, and strike-slip faulting stress regimes. Our numerical results demonstrate that volumetric expansion of the reservoir causes a bending of the fault near the injector and induces shear tractions along the downdip direction of the fault in the basement. These induced shear tractions act to increase the Coulomb failure stress for a normal faulting stress regime, and decrease the Coulomb failure stress for a reverse faulting regime. For a strike-slip faulting stress regime, the induced shear tractions increase the Coulomb failure stress both in the reservoir and basement. The induced normal traction on the fault reduces the Coulomb failure stress in all three tectonic regimes, but is larger in the reservoir than in the basement due to the more pronounced poroelastic effect in the reservoir. As a result, strike-slip stress regimes favor fault reactivation in the basement. Whereas the magnitude of the direct pore pressure increase exceeds the magnitude of induced poroelastic stress change, the poroelastic stress change increases the Coulomb failure stress in the basement fault for the normal

  12. Discussion on the basement topography and its relation with the uranium mineralization in Xiangshan basin

    International Nuclear Information System (INIS)

    Long Qihua; Liu Qingcheng

    2002-01-01

    The depth of the basement and the relation between the basement relief shape and uranium mineralization are discussed by forward and inverse computation for large-scale gravity data in Xiangshan basin. The difference of basement topography result in the inhomogeneous distribution of uranium mineralization. The margin of the basement upheaval section and the variation place of basement topography are the favorable place for uranium mineralization. It's helpful to prospect deep and blind uranium deposit in Xiangshan basin

  13. Basement depressurization using dwelling mechanical exhaust ventilation system

    International Nuclear Information System (INIS)

    Collignan, B.; O'Kelly, P.; Pilch, E.

    2004-01-01

    The mechanical ventilation exhaust system is commonly used in France to generate air renewal into building and especially into dwelling. It consists of a permanent mechanical air extraction from technical rooms (kitchen, bathrooms and toilets) using a unique fan connected to exhaust ducts. Natural air inlets in living room and bed rooms ensure an air flow from living spaces towards technical rooms. To fight against radon into building, the most recognised efficient technique is the Soil Depressurization System (S.D.S.) consisting in depressurizing the house basement. The aim of this study is to test the ability of the dwelling mechanical ventilation system to depressurize the basement in conjunction with air renewal of a house. For that purpose, a S.D.S. has been installed in an experimental house at CSTB during its construction. At first, tests undertaken with a variable velocity fan connected to the S.D.S. have characterised the permeability of the basement. It is shown that basement can be depressurized adequately with a relatively low air flow rate. At a second stage, S.D.S. has been connected to the exhaust ventilation fan used for the mechanical ventilation of the house. Results obtained show the ability of such ventilation system to generate sufficient depressurization in the basement and to ensure simultaneously adequate air change rate in the dwelling. (author)

  14. Reevaluation of the role of the polar groups of collagen in the platelet-collagen interaction.

    OpenAIRE

    Chesney, C. M.; Pifer, D. D.; Crofford, L. J.; Huch, K. M.

    1983-01-01

    Chemical modification of collagen is a tool for exploring the platelet-collagen interaction. Since collagen must polymerize prior to the initiation of platelet aggregation and secretion, modification must be shown to affect platelet-collagen interaction and not collagen-collagen interaction. To address this point, the authors carried out the following chemical modifications on soluble monomeric collagen and preformed fibrillar collagen in parallel: 1) N-and O-acetylation, 2) esterification of...

  15. Basement structures over Rio Grande Rise from gravity inversion

    Science.gov (United States)

    Constantino, Renata; Hackspacker, Peter Christian; Anderson de Souza, Iata; Sousa Lima Costa, Iago

    2017-04-01

    In this study, we show that from satellite-derived gravity field, bathymetry and sediment thicknesses, it is possible to give a 3-D model of the basement over oceanic areas, and for this purpose, we have chosen the Rio Grande Rise, in South Atlantic Ocean, to build a gravity-equivalent basement topography. The advantages of the method applied in this study are manifold: does not depend directly on reflection seismic data; can be applied quickly and with fewer costs for acquiring and interpreting the data; and as the main result, presents the physical surface below the sedimentary layer, which may be different from the acoustic basement. We evaluated the gravity effect of the sediments using the global sediment thickness model of NOAA, fitting a sediment compaction model to observed density values from Deep Sea Drilling Program (DSDP) reports. The Global Relief Model ETOPO1 and constraining data from seismic interpretation on crustal thickness are integrated in the gravity inversion procedure. The modeled Moho depth values vary between 6 to 27 km over the area, being thicker under the Rio Grande Rise and also in the direction of São Paulo Plateau. The inversion for the gravity-equivalent basement topography is applied for a gravity residual data, which is free from the gravity effect of sediments and from the gravity effect of the estimated Moho interface. A description of the basement depth over Rio Grande Rise area is unprecedented in the literature, however, our results could be compared to in situ data, provided by DSDP, and a small difference of only 9 m between our basement depth and leg 516 F was found. Our model shows a rift crossing the entire Rio Grande Rise deeper than previously presented in literature, with depths up to 5 km in the East Rio Grande Rise (ERGR) and deeper in the West Rio Grande Rise (WRGR), reaching 6.4 km. We find several short-wavelengths structures not present in the bathymetry data. Seamounts, guyots and fracture zones are much more

  16. Collagen Conduit Versus Microsurgical Neurorrhaphy

    DEFF Research Database (Denmark)

    Boeckstyns, Michel; Sørensen, Allan Ibsen; Viñeta, Joaquin Fores

    2013-01-01

    To compare repair of acute lacerations of mixed sensory-motor nerves in humans using a collagen tube versus conventional repair.......To compare repair of acute lacerations of mixed sensory-motor nerves in humans using a collagen tube versus conventional repair....

  17. Evaluation of chondrocyte behavior in a new equine collagen scaffold useful for cartilage repair.

    Science.gov (United States)

    Grigolo, B; Desando, G; Cavallo, C; Zini, N; Ghisu, S; Facchini, A

    2011-01-01

    Association of biomaterials with autologous cells can provide a new generation of implantable devices for cartilage repair. An ideal scaffold should possess a preformed three-dimensional shape, fix the cells to the damaged area and prevent their migration into the articular cavity. Furthermore, the constructs should have sufficient mechanical strength to facilitate handling in a clinical setting and stimulate the uniform spreading of cells and a phenotype re-differentiation process. The aim of this study was to verify the ability of an equine collagen membrane to support the growth of human chondrocytes and to allow the re-expression of their original phenotype. This ability was assessed by the evaluation of collagen type I, II and aggrecan mRNA expression by Real-Time PCR. Immunohistochemical analyses were performed to evaluate collagen type I, II and proteoglycans synthesis. Electron microscopy was utilized to highlight the structure of the biomaterial and its interactions with the cells. Our data indicate that human chondrocytes seeded onto a collagen membrane express and produce collagen type II and aggrecan and downregulate the production of collagen type I during the experimental times analyzed. These results provide an in vitro demonstration for the therapeutic potential of autologous chondrocyte transplantation by an equine collagen membrane as a delivery vehicle in a tissue-engineered approach towards the repair of articular cartilage defects.

  18. Novel Vanadium-Loaded Ordered Collagen Scaffold Promotes Osteochondral Differentiation of Bone Marrow Progenitor Cells

    Directory of Open Access Journals (Sweden)

    Ana M. Cortizo

    2016-01-01

    Full Text Available Bone and cartilage regeneration can be improved by designing a functionalized biomaterial that includes bioactive drugs in a biocompatible and biodegradable scaffold. Based on our previous studies, we designed a vanadium-loaded collagen scaffold for osteochondral tissue engineering. Collagen-vanadium loaded scaffolds were characterized by SEM, FTIR, and permeability studies. Rat bone marrow progenitor cells were plated on collagen or vanadium-loaded membranes to evaluate differences in cell attachment, growth and osteogenic or chondrocytic differentiation. The potential cytotoxicity of the scaffolds was assessed by the MTT assay and by evaluation of morphological changes in cultured RAW 264.7 macrophages. Our results show that loading of VOAsc did not alter the grooved ordered structure of the collagen membrane although it increased membrane permeability, suggesting a more open structure. The VOAsc was released to the media, suggesting diffusion-controlled drug release. Vanadium-loaded membranes proved to be a better substratum than C0 for all evaluated aspects of BMPC biocompatibility (adhesion, growth, and osteoblastic and chondrocytic differentiation. In addition, there was no detectable effect of collagen or vanadium-loaded scaffolds on macrophage viability or cytotoxicity. Based on these findings, we have developed a new ordered collagen scaffold loaded with VOAsc that shows potential for osteochondral tissue engineering.

  19. Petrology and geotechnic setting of the basement comple rocks ...

    African Journals Online (AJOL)

    The basement complex, located at the south-eastern borders of Ogoja town in the south-eastern part of Nigeria, consists of two varieties of migmatitic gneisses, namely banded and augen gneisses, which, in some cases, are inter-layered with amphibolite. Many concordant to discordant quartzofeldspathic veins in these ...

  20. Groundwater Exploration in the Basement Complex Around Chibok ...

    African Journals Online (AJOL)

    A geophysical survey employing Schlumberger electrode configuration using vertical electrical sounding (VES) method was carried out around Chibok area within the Basement Complex of north-eastern Nigeria using an ABEM SAS 300C Terrameter with a view to exploring groundwater within the study area.

  1. Source parameter imaging from areomagnetic data of the basement ...

    African Journals Online (AJOL)

    Source parameter imaging from areomagnetic data of the basement rocks in part of the middle Benue trough, Nigeria. GC Onyedim, EA Ariyibi, MO Awoyemi, JB Arubayi, OM Afolabi. Abstract. No Abstract. Journal of Mining and Geology Vol. 42 (2) 2006: pp. 165-173. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT

  2. Aeromagnetic imaging of the basement morphology in part of the ...

    African Journals Online (AJOL)

    Aeromagnetic imaging of the basement morphology in part of the middle Benue trough, Nigeria. GC Onyedim, MO Awoyemi, EA Ariyibi, JB Arubayi. Abstract. No Abstract. Journal of Mining and Geology Vol. 42 (2) 2006: pp. 157-163. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD ...

  3. Geoelectric characterization of Aquifer types in the basement ...

    African Journals Online (AJOL)

    Geoelectric characterization of Aquifer types in the basement complex terrain of parts of Osun state,Nigeria. S Bayode, JS Ojo, MO Olorunfemi. Abstract. No Abstract. Global Journal of Pure and Applied Sciences Vol. 12(3) 2006: 377-385. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT ...

  4. Hydraulic characteristics of a typical basement complex aquifer in ...

    African Journals Online (AJOL)

    Hydraulic characteristics of a typical basement complex aquifer in Ajaokuta, southwestern Nigeria. CC Osadebe, JO Fatoba, S Obrike. Abstract. No Abstract. Ife Journal of Science Vol. 7(2) 2005: 297-303. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  5. an investigation of basement fracture pattern in a part of ...

    African Journals Online (AJOL)

    DR ANIFOWOSE

    The basement complex of southwestern Nigeria has undergone severe tectonic deformation over the geologic past, resulting in various degrees of fracturing and folding, even to the extent of complete obliteration of primary structures except for some places. This study focuses on Akoko area which is dominated by hills of ...

  6. Magnetic basement in the central Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, K.V.L.N.S.; Ramana, M.V.; Ramprasad, T.; Desa, M.; Subrahmanyam, V.; Krishna, K.S.; Rao, M.M.M.

    . The N10-12 degrees W trending subsurface 85 degrees E Ridge buried under 2 to 3 km thick sediments is a prominent tectonic feature. Offshore basins characterised by deeper magnetic basement (approx. 9 km) and 100-200 km wide are present on either sides...

  7. Basement configuration of KG offshore basin from magnetic anomalies

    Indian Academy of Sciences (India)

    Marine magnetic anomalies along three representative profiles falling between shelf break and continent–ocean boundary in the offshore Krishna–Godavari basin were quantitatively interpreted for understandingthe nature and structure of the magnetic basement using inversion technique. The interpretation of ...

  8. Is vitamin C able to prevent premature rupture of membranes?

    OpenAIRE

    Citra Aryanti

    2016-01-01

    Premature rupture of membranes (PROM) is leakage of amniotic fluid through ruptured chorioamniotic membranes that occur before starting the labor pain at any gestational age. This is one of the most common problems in obstetrics with many adverse pregnancy outcomes. Main and final mechanisms of membrane rupture is disturbances in its collagen content metabolism. Vitamin C is found to stabilize the cross link triple helix collagen structure and scavange oxidant that involved in PPROM. Associat...

  9. Stimulation of MMP-11 (stromelysin-3) expression in mouse fibroblasts by cytokines, collagen and co-culture with human breast cancer cell lines

    International Nuclear Information System (INIS)

    Selvey, Saxon; Haupt, Larisa M; Thompson, Erik W; Matthaei, Klaus I; Irving, Michael G; Griffiths, Lyn R

    2004-01-01

    Matrix metalloproteinases (MMPs) are central to degradation of the extracellular matrix and basement membrane during both normal and carcinogenic tissue remodeling. MT1-MMP (MMP-14) and stromelysin-3 (MMP-11) are two members of the MMP family of proteolytic enzymes that have been specifically implicated in breast cancer progression. Expressed in stromal fibroblasts adjacent to epithelial tumour cells, the mechanism of MT1-MMP and MMP-11 induction remains unknown. To investigate possible mechanisms of induction, we examined the effects of a number of plausible regulatory agents and treatments that may physiologically influence MMP expression during tumour progression. Thus NIH3T3 and primary mouse embryonic fibroblasts (MEFs) were: a) treated with the cytokines IL-1β, IL-2, IL-6, IL-8 and TGF-β for 3, 6, 12, 24, and 48 hours; b) grown on collagens I, IV and V; c) treated with fibronectin, con-A and matrigel; and d) co-cultured with a range of HBC (human breast cancer) cell lines of varied invasive and metastatic potential. Competitive quantitative RT-PCR indicated that MMP-11 expression was stimulated to a level greater than 100%, by 48 hour treatments of IL-1β, IL-2, TGF-β, fibronectin and collagen V. No other substantial changes in expression of MMP-11 or MT1-MMP in either tested fibroblast culture, under any treatment conditions, were observed. We have demonstrated significant MMP-11 stimulation in mouse fibroblasts using cytokines, matrix constituents and HBC cell lines, and also some inhibition of MT1-MMP. Our data suggest that the regulation of these genes in the complex stromal-epithelial interactions that occur in human breast carcinoma, is influenced by several mechanisms

  10. Stimulation of MMP-11 (stromelysin-3 expression in mouse fibroblasts by cytokines, collagen and co-culture with human breast cancer cell lines

    Directory of Open Access Journals (Sweden)

    Matthaei Klaus I

    2004-07-01

    Full Text Available Abstract Background Matrix metalloproteinases (MMPs are central to degradation of the extracellular matrix and basement membrane during both normal and carcinogenic tissue remodeling. MT1-MMP (MMP-14 and stromelysin-3 (MMP-11 are two members of the MMP family of proteolytic enzymes that have been specifically implicated in breast cancer progression. Expressed in stromal fibroblasts adjacent to epithelial tumour cells, the mechanism of MT1-MMP and MMP-11 induction remains unknown. Methods To investigate possible mechanisms of induction, we examined the effects of a number of plausible regulatory agents and treatments that may physiologically influence MMP expression during tumour progression. Thus NIH3T3 and primary mouse embryonic fibroblasts (MEFs were: a treated with the cytokines IL-1β, IL-2, IL-6, IL-8 and TGF-β for 3, 6, 12, 24, and 48 hours; b grown on collagens I, IV and V; c treated with fibronectin, con-A and matrigel; and d co-cultured with a range of HBC (human breast cancer cell lines of varied invasive and metastatic potential. Results Competitive quantitative RT-PCR indicated that MMP-11 expression was stimulated to a level greater than 100%, by 48 hour treatments of IL-1β, IL-2, TGF-β, fibronectin and collagen V. No other substantial changes in expression of MMP-11 or MT1-MMP in either tested fibroblast culture, under any treatment conditions, were observed. Conclusion We have demonstrated significant MMP-11 stimulation in mouse fibroblasts using cytokines, matrix constituents and HBC cell lines, and also some inhibition of MT1-MMP. Our data suggest that the regulation of these genes in the complex stromal-epithelial interactions that occur in human breast carcinoma, is influenced by several mechanisms.

  11. The concept of an artificial tympanic membrane

    NARCIS (Netherlands)

    Feenstra, L.; Kohn, F.E.; Feijen, Jan

    1984-01-01

    A review is given of the development of the concept of an artifical tympanic membrane. Starting with homologous tympanic membranes we compared biodegradable collagen materials (homologous and heterologous) and biodegradable synthetic materials, poly-glycolic acid, poly-lactic acid and poly-α-amino

  12. Ultrastructural immunocytochemical localization of chondroitin sulfate proteoglycan in Bruch's membrane of the rat

    DEFF Research Database (Denmark)

    Lin, W L; Essner, E; McCarthy, K J

    1992-01-01

    Two monoclonal antibodies (Mab 4D5 and 2D6) raised against the core protein of a basement membrane chondroitin sulfate proteoglycan from Reichert's membrane of the rat, were used for ultrastructural immunoperoxidase localization of this protein in Bruch's membrane of the rat. Immunoreactivity for...

  13. Increasing extracellular matrix collagen level and MMP activity induces cyst development in polycystic kidney disease

    Directory of Open Access Journals (Sweden)

    Liu Bin

    2012-09-01

    Full Text Available Abstract Background Polycystic Kidney Disease (PKD kidneys exhibit increased extracellular matrix (ECM collagen expression and metalloproteinases (MMPs activity. We investigated the role of these increases on cystic disease progression in PKD kidneys. Methods We examined the role of type I collagen (collagen I and membrane bound type 1 MMP (MT1-MMP on cyst development using both in vitro 3 dimensional (3D collagen gel culture and in vivo PCK rat model of PKD. Results We found that collagen concentration is critical in controlling the morphogenesis of MDCK cells cultured in 3D gels. MDCK cells did not form 3D structures at collagen I concentrations lower than 1 mg/ml but began forming tubules when the concentration reaches 1 mg/ml. Significantly, these cells began to form cyst when collagen I concentration reached to 1.2 mg/ml, and the ratios of cyst to tubule structures increased as the collagen I concentration increased. These cells exclusively formed cyst structures at a collagen I concentration of 1.8 mg/ml or higher. Overexpression of MT1-MMP in MDCK cells significantly induced cyst growth in 3D collagen gel culture. Conversely, inhibition of MMPs activity with doxycycline, a FDA approved pan-MMPs inhibitor, dramatically slowed cyst growth. More importantly, the treatment of PCK rats with doxycycline significantly decreased renal tubule cell proliferation and markedly inhibited the cystic disease progression. Conclusions Our data suggest that increased collagen expression and MMP activity in PKD kidneys may induce cyst formation and expansion. Our findings also suggest that MMPs may serve as a therapeutic target for the treatment of human PKD.

  14. Chondrogenic differentiation of mesenchymal stem cells in a leakproof collagen sponge

    International Nuclear Information System (INIS)

    Chen Guoping; Akahane, Daisuke; Kawazoe, Naoki; Yamamoto, Katsuyuki; Tateishi, Tetsuya

    2008-01-01

    A three-dimensional culture of mesenchymal stem cells (MSCs) in a porous scaffold has been developed as a promising strategy for cartilage tissue engineering. The chondrogenic differentiation of MSCs derived from human bone marrow was studied by culturing the cells in a novel scaffold constructed of leakproof collagen sponge. All the surfaces of the collagen sponge except the top were wrapped with a membrane that has pores smaller than the cells to protect against cell leakage during cell seeding. The cells adhered to the collagen, distributed evenly, and proliferated to fill the spaces in the sponge. Cell seeding efficiency was greater than 95%. The MSCs cultured in the collagen sponge in the presence of TGF-β3 and BMP6 expressed a high level of genes encoding type II and type X collagen, sox9, and aggrecan. Histological examination by HE staining indicated that the differentiated cells showed a round morphology. The extracellular matrices were positively stained by safranin O and toluidine blue. Immunostaining with anti-type II collagen and anti-cartilage proteoglycan showed that type II collagen and cartilage proteoglycan were detected around the cells. These results suggest the chondrogenic differentiation of MSCs when cultured in the collagen sponge in the presence of TGF-β3 and BMP6

  15. Reconstituted collagen fibrils. Fibrillar and molecular stability of the collagen upon maturation in vitro.

    OpenAIRE

    Danielsen, C C

    1984-01-01

    During the maturation in vitro of reconstituted collagen fibrils prepared from rat skin, the mechanical and thermal stability of collagen increased and the pepsin-solubility decreased. At the same time a larger fraction of the pepsin-soluble collagen attained a lower molecular thermal stability that resulted in a biphasic thermal transition of the soluble collagen. Type-I collagen, with a similar biphasic thermal transition, was isolated from acid-insoluble rat skin collagen.

  16. Oriented Collagen Scaffolds for Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Shohta Kodama

    2012-03-01

    Full Text Available Oriented collagen scaffolds were developed in the form of sheet, mesh and tube by arraying flow-oriented collagen string gels and dehydrating the arrayed gels. The developed collagen scaffolds can be any practical size with any direction of orientation for tissue engineering applications. The birefringence of the collagen scaffolds was quantitatively analyzed by parallel Nicols method. Since native collagen in the human body has orientations such as bone, cartilage, tendon and cornea, and the orientation has a special role for the function of human organs, the developed various types of three-dimensional oriented collagen scaffolds are expected to be useful biomaterials for tissue engineering and regenerative medicines.

  17. Geoelectrical characterisation of basement aquifers: the case of Iberekodo, southwestern Nigeria

    Science.gov (United States)

    Aizebeokhai, Ahzegbobor P.; Oyeyemi, Kehinde D.

    2018-03-01

    Basement aquifers, which occur within the weathered and fractured zones of crystalline bedrocks, are important groundwater resources in tropical and subtropical regions. The development of basement aquifers is complex owing to their high spatial variability. Geophysical techniques are used to obtain information about the hydrologic characteristics of the weathered and fractured zones of the crystalline basement rocks, which relates to the occurrence of groundwater in the zones. The spatial distributions of these hydrologic characteristics are then used to map the spatial variability of the basement aquifers. Thus, knowledge of the spatial variability of basement aquifers is useful in siting wells and boreholes for optimal and perennial yield. Geoelectrical resistivity is one of the most widely used geophysical methods for assessing the spatial variability of the weathered and fractured zones in groundwater exploration efforts in basement complex terrains. The presented study focuses on combining vertical electrical sounding with two-dimensional (2D) geoelectrical resistivity imaging to characterise the weathered and fractured zones in a crystalline basement complex terrain in southwestern Nigeria. The basement aquifer was delineated, and the nature, extent and spatial variability of the delineated basement aquifer were assessed based on the spatial variability of the weathered and fractured zones. The study shows that a multiple-gradient array for 2D resistivity imaging is sensitive to vertical and near-surface stratigraphic features, which have hydrological implications. The integration of resistivity sounding with 2D geoelectrical resistivity imaging is efficient and enhances near-surface characterisation in basement complex terrain.

  18. A fall-out shelter or basement structure

    International Nuclear Information System (INIS)

    Blatchford, J.M.A.

    1982-01-01

    A strong structure of precast concrete for use as a fallout shelter, tank, basement structure, blast-proof garage is described. It consists of several upright, concrete wall elements, including L-shaped sections, and at least one concrete roof element. The concrete elements are preferably encased in, and may also be supported on, a concrete surround which is formed in situ and which may be secured to the elements by projecting links. The structure may be assembled as an underground or above-ground building. This invention provides a strong structure of quite large span which is relatively simple in construction and can be rapidly assembled. (U.K.)

  19. Air exchange rates and migration of VOCs in basements and residences.

    Science.gov (United States)

    Du, L; Batterman, S; Godwin, C; Rowe, Z; Chin, J-Y

    2015-12-01

    Basements can influence indoor air quality by affecting air exchange rates (AERs) and by the presence of emission sources of volatile organic compounds (VOCs) and other pollutants. We characterized VOC levels, AERs, and interzonal flows between basements and occupied spaces in 74 residences in Detroit, Michigan. Flows were measured using a steady-state multitracer system, and 7-day VOC measurements were collected using passive samplers in both living areas and basements. A walk-through survey/inspection was conducted in each residence. AERs in residences and basements averaged 0.51 and 1.52/h, respectively, and had strong and opposite seasonal trends, for example, AERs were highest in residences during the summer, and highest in basements during the winter. Airflows from basements to occupied spaces also varied seasonally. VOC concentration distributions were right-skewed, for example, 90th percentile benzene, toluene, naphthalene, and limonene concentrations were 4.0, 19.1, 20.3, and 51.0 μg/m(3), respectively; maximum concentrations were 54, 888, 1117, and 134 μg/m(3). Identified VOC sources in basements included solvents, household cleaners, air fresheners, smoking, and gasoline-powered equipment. The number and type of potential VOC sources found in basements are significant and problematic, and may warrant advisories regarding the storage and use of potentially strong VOCs sources in basements. Few IAQ studies have examined basements. A sizable volume of air can flow between the basement and living area, and AERs in these two zones can differ considerably. In many residences, the basement contains significant emission sources and contributes a large fraction of VOC concentrations found in the living area. Exposures can be lowered by removing VOC sources from the basement; other exposure management options, such as local ventilation or isolation, are unlikely to be practical. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Real-time-guided bone regeneration around standardized critical size calvarial defects using bone marrow-derived mesenchymal stem cells and collagen membrane with and without using tricalcium phosphate: an in vivo micro-computed tomographic and histologic experiment in rats

    Science.gov (United States)

    Al-Hezaimi, Khalid; Ramalingam, Sundar; Al-Askar, Mansour; ArRejaie, Aws S; Nooh, Nasser; Jawad, Fawad; Aldahmash, Abdullah; Atteya, Muhammad; Wang, Cun-Yu

    2016-01-01

    The aim of the present real time in vivo micro-computed tomography (µCT) and histologic experiment was to assess the efficacy of guided bone regeneration (GBR) around standardized calvarial critical size defects (CSD) using bone marrow-derived mesenchymal stem cells (BMSCs), and collagen membrane (CM) with and without tricalcium phosphate (TCP) graft material. In the calvaria of nine female Sprague-Dawley rats, full-thickness CSD (diameter 4.6 mm) were created under general anesthesia. Treatment-wise, rats were divided into three groups. In group 1, CSD was covered with a resorbable CM; in group 2, BMSCs were filled in CSD and covered with CM; and in group 3, TCP soaked in BMSCs was placed in CSD and covered with CM. All defects were closed using resorbable sutures. Bone volume and bone mineral density of newly formed bone (NFB) and remaining TCP particles and rate of new bone formation was determined at baseline, 2, 4, 6, and 10 weeks using in vivo µCT. At the 10th week, the rats were killed and calvarial segments were assessed histologically. The results showed that the hardness of NFB was similar to that of the native bone in groups 1 and 2 as compared to the NFB in group 3. Likewise, values for the modulus of elasticity were also significantly higher in group 3 compared to groups 1 and 2. This suggests that TCP when used in combination with BMSCs and without CM was unable to form bone of significant strength that could possibly provide mechanical “lock” between the natural bone and NFB. The use of BMSCs as adjuncts to conventional GBR initiated new bone formation as early as 2 weeks of treatment compared to when GBR is attempted without adjunct BMSC therapy. PMID:27025260

  1. Micromechanical bending of single collagen fibrils using atomic force microscopy

    NARCIS (Netherlands)

    Yang, Lanti; van der Werf, Kees O; Koopman, Bart F J M; Subramaniam, Vinod; Bennink, Martin L; Dijkstra, Pieter J; Feijen, Jan

    A new micromechanical technique was developed to study the mechanical properties of single collagen fibrils. Single collagen fibrils, the basic components of the collagen fiber, have a characteristic highly organized structure. Fibrils were isolated from collagenous materials and their mechanical

  2. Biology, chemistry and pathology of collagen

    Energy Technology Data Exchange (ETDEWEB)

    Fleischmajer, R.; Olsen, B.R.; Kuhn, K.

    1985-01-01

    This book consists of five parts and a section of poster papers. Some of the articles are: Structure of the Type II Collagen Gene; Structural and Functional Analysis of the Genes for ..cap alpha..2(1) and ..cap alpha..1(III) collagens; Structure and Expression of the Collagen Genes of C. Elegans; Molecular Basis of Clinical Heterogeneity in the Ehlers-Danlos Syndrome; and Normal and Mutant Human Collagen Genes.

  3. Building blocks of Collagen based biomaterial devices

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Building blocks of Collagen based biomaterial devices. Collagen as a protein. Collagen in tissues and organs. Stabilizing and cross linking agents. Immunogenicity. Hosts (drugs). Controlled release mechanisms of hosts. Biodegradability, workability into devices ...

  4. Collagen breakdown products and lung collagen metabolism: an in vitro study on fibroblast cultures.

    OpenAIRE

    Gardi, C.; Calzoni, P.; Marcolongo, P.; Cavarra, E.; Vanni, L.; Lungarella, G.

    1994-01-01

    BACKGROUND--In fibrotic diseases such as pulmonary fibrosis there is evidence suggesting enhanced synthesis and degradation of lung connective tissue components, including collagen. It has therefore been hypothesised that products of collagen degradation may have a role in the promotion of collagen deposition. In support of this hypothesis, it has recently been shown that intravenous injection of lung collagen degradation products in experimental animals stimulated collagen synthesis leading ...

  5. Tectonic and neotectonic implications of a new basement map of the Lower Tagus Valley, Portugal

    OpenAIRE

    Carvalho, João P. G.; Rabeh, Taha; Dias, Rui; Dias, Ruben P.; Pinto, Carlos C.; Oliveira, José Tomás; Cunha, Teresa Arriaga; Borges, José Fernando

    2014-01-01

    In this paper we present a new basement (defined here as Paleozoic, Precambrian and Mesozoic igneous rocks) map of the Lower Tagus Valley area. This map is a contribution to the understanding of the structural evolution of the top of the basement in the Lower Tagus Valley area during the Mesozoic and Cenozoic Eras. The map was produced using aeromagnetic, well, seismic reflection and geological outcrop data. It shows unprecedented details of the geometry of the basement rock's sur...

  6. X-linked Alport syndrome associated with a synonymous p.Gly292Gly mutation alters the splicing donor site of the type IV collagen alpha chain 5 gene.

    Science.gov (United States)

    Fu, Xue Jun; Nozu, Kandai; Eguchi, Aya; Nozu, Yoshimi; Morisada, Naoya; Shono, Akemi; Taniguchi-Ikeda, Mariko; Shima, Yuko; Nakanishi, Koichi; Vorechovsky, Igor; Iijima, Kazumoto

    2016-10-01

    X-linked Alport syndrome (XLAS) is a progressive hereditary nephropathy caused by mutations in the type IV collagen alpha chain 5 gene (COL4A5). Although many COL4A5 mutations have previously been identified, pathogenic synonymous mutations have not yet been described. A family with XLAS underwent mutational analyses of COL4A5 by PCR and direct sequencing, as well as transcript analysis of potential splice site mutations. In silico analysis was also conducted to predict the disruption of splicing factor binding sites. Immunohistochemistry (IHC) of kidney biopsies was used to detect α2 and α5 chain expression. We identified a hemizygous point mutation, c.876A>T, in exon 15 of COL4A5 in the proband and his brother, which is predicted to result in a synonymous amino acid change, p.(Gly292Gly). Transcript analysis showed that this mutation potentially altered splicing because it disrupted the splicing factor binding site. The kidney biopsy of the proband showed lamellation of the glomerular basement membrane (GBM), while IHC revealed negative α5(IV) staining in the GBM and Bowman's capsule, which is typical of XLAS. This is the first report of a synonymous COL4A5 substitution being responsible for XLAS. Our findings suggest that transcript analysis should be conducted for the future correct assessment of silent mutations.

  7. Structural analysis of a fractured basement reservoir, central Yemen

    Science.gov (United States)

    Veeningen, Resi; Rice, Hugh; Schneider, Dave; Grasemann, Bernhard; Decker, Kurt

    2013-04-01

    The Pan-African Arabian-Nubian Shield (ANS), within which Yemen lies, formed as a result of Neoproterozoic collisional events between c. 870-550 Ma. Several subsequent phases of extension occurred, from the Mesozoic (due to the breakup of Gondwana) to the Recent (forming the Gulf of Aden and the Red Sea). These resulted in the formation of numerous horst- and-graben structures and the development of fractured basement reservoirs in the southeast part of the ANS. Two drill cores from the Mesozoic Marib-Shabwa Basin, central Yemen, penetrated the upper part of the Pan-African basement. The cores show both a lithological and structural inhomogeneity, with variations in extension-related deformation structures such as dilatational breccias, open fractures and closed veins. At least three deformation events have been recognized: D1) Ductile to brittle NW-SE directed faulting during cooling of a granitic pluton. U-Pb zircon ages revealed an upper age limit for granite emplacement at 627±3.5 Ma. As these structures show evidence for ductile deformation, this event must have occurred during the Ediacaran, shortly after intrusion, since Rb/Sr and (U-Th)/He analyses show that subsequent re-heating of the basement did not take place. D2) The development of shallow dipping, NNE-SSW striking extensional faults that formed during the Upper Jurassic, simultaneously with the formation of the Marib-Shabwa Basin. These fractures are regularly cross-cut by D3. D3) Steeply dipping NNE-SSW to ENE-WSW veins that are consistent with the orientation of the opening of the Gulf of Aden. These faults are the youngest structures recognized. The formation of ductile to brittle faults in the granite (D1) resulted in a hydrothermally altered zone ca. 30 cm wide replacing (mainly) plagioclase with predominantly chlorite, as well as kaolinite and heavy element minerals such as pyrite. The alteration- induced porosity has an average value of 20%, indicating that the altered zone is potentially a

  8. Collagen cross linking: Current perspectives

    Directory of Open Access Journals (Sweden)

    Srinivas K Rao

    2013-01-01

    Full Text Available Keratoconus is a common ectatic disorder occurring in more than 1 in 1,000 individuals. The condition typically starts in adolescence and early adulthood. It is a disease with an uncertain cause and its progression is unpredictable, but in extreme cases, vision deteriorates and can require corneal transplant surgery. Corneal collagen cross-linking (CCL with riboflavin (C3R is a recent treatment option that can enhance the rigidity of the cornea and prevent disease progression. Since its inception, the procedure has evolved with newer instrumentation, surgical techniques, and is also now performed for expanded indications other than keratoconus. With increasing experience, newer guidelines regarding optimization of patient selection, the spectrum of complications and their management, and combination procedures are being described. This article in conjunction with the others in this issue, will try and explore the uses of collagen cross-linking (CXL in its current form.

  9. Rac1 is essential for basement membrane-dependent epiblast survival

    DEFF Research Database (Denmark)

    He, Xiaowen; Liu, Jie; Qi, Yanmei

    2010-01-01

    biological process are largely unknown. Here we demonstrate that Rac1 ablation in embryonic stem cell-derived embryoid bodies (EBs) leads to massive apoptosis of epiblast cells in contact with the BM. Expression of wild-type Rac1 in the mutant EBs rescues the BM-contacting epiblast, while expression...... of a constitutively active Rac1 additionally blocks the apoptosis of inner cells and cavitation, indicating that the spatially regulated activation of Rac1 is required for epithelial cyst formation. We further show that Rac1 is activated through integrin-mediated recruitment of the Crk-DOCK180 complex and mediates BM...

  10. Autoantibodies to myeloperoxidase aggravate mild anti-glomerular-basement-membrane-mediated glomerular injury in the rat

    NARCIS (Netherlands)

    Heeringa, P.; Brouwer, E.; Klok, P. A.; Huitema, M. G.; van den Born, J.; Weening, J. J.; Kallenberg, C. G.

    1996-01-01

    Autoantibodies to myeloperoxidase (MPO) are present in sera from patients with various forms of vasculitis-associated glomerulonephritis. Evidence for a pathogenic role of anti-MPO antibodies has been provided mainly by in vitro studies. We studied the pathogenic role of autoantibodies to MPO in a

  11. Structural analysis of how podocytes detach from the glomerular basement membrane under hypertrophic stress

    Directory of Open Access Journals (Sweden)

    Wilhelm eKriz

    2014-12-01

    Full Text Available Podocytes are lost by detachment from the GBM as viable cells; details are largely unknown. We studied this process in the rat after growth stimulation with FGF-2. Endothelial and mesangial cells responded by hyperplasia, podocytes underwent hypertrophy, but, in the long run, developed various changes that could either be interpreted showing progressing stages in detachment from the GBM or stages leading to a tighter attachment by foot process effacement (FPE. This occurred in microdomains within the same podocyte; thus features of detachment and of reinforced attachment may simultaneously be found in the same podocyte.(1 Initially, hypertrophied podocytes underwent cell body attenuation and formed large pseudocysts, i.e. expansions of the subpodocyte space.(2 Podocytes entered the process of FPE starting with the retraction of foot processes and the replacement of the slit diaphragm by occluding junctions thereby sealing the filtration slits. Successful completion of this process led to broad attachments of podocyte cell bodies to the GBM. (3 Failure of sealing the slits led to gaps of varying width between retracting foot processes facilitating the outflow of the filtrate from the GBM.(4 Since those gaps are frequently overarched by broadened primary processes the drainage of the filtrate into the Bowman's space may be hindered leading to the formation of small pseudocysts associated with bare areas of GBM.(5 The merging of pseudocysts created a system of communicating chambers through which the filtrate has to pass to reach Bowman's space. Multiple flow resistances in series likely generated an expansile force on podocytes contributing to detachment.(6 Such a situation appears to proceed to complete disconnection generally of a group of podocytes owing to the junctional connections between them. (7 Since such groups of detaching podocytes generally make contact to parietal cells, they start the formation of tuft adhesions to Bowman's capsule.

  12. Histopathological and ultrastructural analysis of vestibular endorgans in Meniere's disease reveals basement membrane pathology

    Directory of Open Access Journals (Sweden)

    McCall Andrew A

    2009-06-01

    Full Text Available Abstract Background We report the systematic analysis of the ultrastructural and cytological histopathology of vestibular endorgans acquired from labyrinthectomy in Meniere's disease. Methods 17 subjects with intractable Meniere's disease and ipsilateral non-serviceable hearing presenting to the Neurotology Clinic from 1997 to 2006 who chose ablative labyrinthectomy (average age = 62 years; range 29–83 years participated. The average duration of symptoms prior to surgery was 7 years (range 1–20 years. Results Nearly all vestibular endorgans demonstrated varying degrees of degeneration. A monolayer of epithelial cells occurred significantly more frequently in the horizontal cristae (12/13 = 92% (p Conclusion Systematic histopathological analysis of the vestibular endorgans from Meniere's disease demonstrated neuroepithelial degeneration which was highly correlated with an associated BM thickening. Other findings included hair cell and supporting cell microvessicles, increased intercellular clear spaces in the stroma, and endothelial cell vacuolization and stromal perivascular BM thickening.

  13. Lack of endothelial nitric oxide synthase aggravates murine accelerated anti-glomerular basement membrane glomerulonephritis

    NARCIS (Netherlands)

    Heeringa, P; van Goor, H; Itoh-Lindstrom, Y; Maeda, N; Falk, RJ; Assmann, KJM; Kallenberg, CGM; Jennette, JC

    Nitric oxide (NO) radicals generated by endothelial nitric oxide synthase (eNOS) are involved in the regulation of vascular tone. In addition, NO radicals derived from eNOS inhibit platelet aggregation and leukocyte adhesion to the endothelium and, thus, may have anti-inflammatory effects. To study

  14. FIBROBLAST GROWTH FACTOR-2 DURING POSTNATAL DEVELOPMENT OF THE TRACHEAL BASEMENT MEMBRANE ZONE. (R827442)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  15. Matrigel Basement Membrane Matrix influences expression of microRNAs in cancer cell lines

    International Nuclear Information System (INIS)

    Price, Karina J.; Tsykin, Anna; Giles, Keith M.; Sladic, Rosemary T.; Epis, Michael R.; Ganss, Ruth; Goodall, Gregory J.; Leedman, Peter J.

    2012-01-01

    Highlights: ► Matrigel alters cancer cell line miRNA expression relative to culture on plastic. ► Many identified Matrigel-regulated miRNAs are implicated in cancer. ► miR-1290, -210, -32 and -29b represent a Matrigel-induced miRNA signature. ► miR-32 down-regulates Integrin alpha 5 (ITGA5) mRNA. -- Abstract: Matrigel is a medium rich in extracellular matrix (ECM) components used for three-dimensional cell culture and is known to alter cellular phenotypes and gene expression. microRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression and have roles in cancer. While miRNA profiles of numerous cell lines cultured on plastic have been reported, the influence of Matrigel-based culture on cancer cell miRNA expression is largely unknown. This study investigated the influence of Matrigel on the expression of miRNAs that might facilitate ECM-associated cancer cell growth. We performed miRNA profiling by microarray using two colon cancer cell lines (SW480 and SW620), identifying significant differential expression of miRNAs between cells cultured in Matrigel and on plastic. Many of these miRNAs have previously been implicated in cancer-related processes. A common Matrigel-induced miRNA signature comprised of up-regulated miR-1290 and miR-210 and down-regulated miR-29b and miR-32 was identified using RT-qPCR across five epithelial cancer cell lines (SW480, SW620, HT-29, A549 and MDA-MB-231). Experimental modulation of these miRNAs altered expression of their known target mRNAs involved in cell adhesion, proliferation and invasion, in colon cancer cell lines. Furthermore, ITGA5 was identified as a novel putative target of miR-32 that may facilitate cancer cell interactions with the ECM. We propose that culture of cancer cell lines in Matrigel more accurately recapitulates miRNA expression and function in cancer than culture on plastic and thus is a valuable approach to the in vitro study of miRNAs.

  16. FLUORESCENCE OVERLAY ANTIGEN MAPPING OF THE EPIDERMAL BASEMENT-MEMBRANE ZONE .1. GEOMETRIC ERRORS

    NARCIS (Netherlands)

    BRUINS, S; DEJONG, MCJM; HEERES, K; WILKINSON, MHF; JONKMAN, MF; VANDERMEER, JB

    To identify in tissue sections the relative positions of antigen distributions close to the resolving power of the microscope, we have developed the fluorescence overlay antigen mapping (FOAM) procedure. As this technique makes high demands on the geometric fidelity of the overlay image, it is

  17. FLUORESCENCE OVERLAY ANTIGEN MAPPING OF THE EPIDERMAL BASEMENT-MEMBRANE ZONE .2. COLOR FIDELITY

    NARCIS (Netherlands)

    BRUINS, S; DEJONG, MCJM; HEERES, K; WILKINSON, MHF; JONKMAN, MF; VANDERMEER, JB

    In this second report on the fluorescence overlay antigen mapping (FOAM) technique, we highlight some of the errors that may influence faithful color rendition of slide preparations using triple antigen immunofluorescence staining. Reliable interpretation of multicolor fluorescence images requires

  18. Dye Transport across the Retinal Basement Membrane of the Blowfly Calliphora erythrocephala

    NARCIS (Netherlands)

    Weyrauther, E.; Roebroek, J.G.H.; Stavenga, D.G.

    In the blowfly, Calliphora erythrocephala, transport of dye into or out of the retina, following injection into the eye or thorax, was investigated, mainly by microspectrophotometry and fluorimetry. After injection into the eye, Phenol Red, Trypan Blue, Lucifer Yellow and 9-amino-acridine were

  19. CORRELATIVE LIGHT AND IMMUNOHISTOLOGICAL STUDY OF THE BASEMENT MEMBRANE OF THE HUMAN SQUAMOUS CERVICAL CARCINOMA

    OpenAIRE

    Masato, YAMASAKI; Gaiko, UEDA; Masaki, INOUE; Yoshiaki, TANAKA; IKeiichi, KURACH; Department of Obstetrics and Gynecology, Osaha University Medical School; Department of Obstetrics and Gynecology, Osaha University Medical School; Department of Obstetrics and Gynecology, Osaha University Medical School; Department of Obstetrics and Gynecology, Osaha University Medical School; Department of Obstetrics and Gynecology, Osaha University Medical School

    1980-01-01

    子宮頚部扁平上皮癌に基底膜は存在するか否か光顕・電顕的に多くの研究がなされてきた.1968年Beutner et al.はbullous pemphigioid患者血清が扁平上皮に対する抗基底膜抗体を含むことが明らかにされた.今回,我々は子宮頚部の上皮内癌3例,微小浸潤癌1例,浸潤癌27例を用い,凍結切片を作製し,抗基底膜抗体を含むbullous pemphigioid患者血清を用い蛍光抗体法による基底膜の観察を行なった.更に同一症例について,PAS及びMucin染色を行なった.蛍光抗体法による基底膜の観察では上皮内癌3例及び正常上皮では全て連続した蛍光の線が認められた.浸潤癌27例中7例に陽性で,keratinizing type 1/3, large cell type 6/23, small cell type 1/1例に陽性所見を認めた.CPL分類ではC型3/9,P型5/16,L型0/2が陽性であった.間質細胞反応との関連では細胞浸潤の軽度のもの5/16例,中等度・高度のもの3/11例に陽性であった.PAS及びMucin染色との比較検討を行なうと,PAS陽性基底膜例では3...

  20. Formation evaluation of fractured basement, Cambay Basin, India

    International Nuclear Information System (INIS)

    Gupta, Saurabh Datta; Farooqui, M Y; Chatterjee, Rima

    2012-01-01

    Unconventional reservoirs such as fractured basalts, shale gas and tight sand are currently playing an important role in producing a significant amount of hydrocarbon. The Deccan Trap basaltic rocks form the basement of the Cambay Basin, India, and hold commercially producible hydrocarbon. In this study two wells drilled through fractured basalts are chosen for evaluating the lithology, porosity and oil saturation of the reservoir sections. Well logs, such as gamma ray, high resolution resistivity, litho density, compensated neutron and elemental capture spectroscopy, have been used in cross-plotting techniques for lithology and mineral identification. Formation micro imagery log data have been analysed to quantify the fractures and porosity in the fractured reservoirs for a well in the south Ahmedabad block of the Cambay Basin. The results of the analysis of two wells are presented and discussed and they are found to be in good agreement with geological and production data. (paper)

  1. ENFORCEMENT OF FINANCIAL BASEMENTS AS A FACTOR OF TERRITORIES DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    E.N. Sidorova

    2007-06-01

    Full Text Available Article contains description of structure of regional finance resources, discloses the sources of financing, describes the role of budgeting. Problems and possible ways of solution of inter-budget relationships optimisation are described with the purpose of increasing of financial prosperity of territories. Overall role of optimisation as one of the most important factors of strengthening of financial basement of territories is described along with the necessity of considering the budget process as stimulated factor for regional economic systems development. Suggestions on substitution of cost method of budget resources management by the model of outcomes management and further development of mechanisms of territorial bodies interaction with economic entities on the base of state-private partnership were proposed.

  2. Age of Izu-Bonin-Mariana arc basement

    Science.gov (United States)

    Ishizuka, Osamu; Hickey-Vargas, Rosemary; Arculus, Richard J.; Yogodzinski, Gene M.; Savov, Ivan P.; Kusano, Yuki; McCarthy, Anders; Brandl, Philipp A.; Sudo, Masafumi

    2018-01-01

    Documenting the early tectonic and magmatic evolution of the Izu-Bonin-Mariana (IBM) arc system in the Western Pacific is critical for understanding the process and cause of subduction initiation along the current convergent margin between the Pacific and Philippine Sea plates. Forearc igneous sections provide firm evidence for seafloor spreading at the time of subduction initiation (52 Ma) and production of "forearc basalt". Ocean floor drilling (International Ocean Discovery Program Expedition 351) recovered basement-forming, low-Ti tholeiitic basalt crust formed shortly after subduction initiation but distal from the convergent margin (nominally reararc) of the future IBM arc (Amami Sankaku Basin: ASB). Radiometric dating of this basement gives an age range (49.3-46.8 Ma with a weighted average of 48.7 Ma) that overlaps that of basalt in the present-day IBM forearc, but up to 3.3 m.y. younger than the onset of forearc basalt activity. Similarity in age range and geochemical character between the reararc and forearc basalts implies that the ocean crust newly formed by seafloor spreading during subduction initiation extends from fore- to reararc of the present-day IBM arc. Given the age difference between the oldest forearc basalt and the ASB crust, asymmetric spreading caused by ridge migration might have taken place. This scenario for the formation of the ASB implies that the Mesozoic remnant arc terrane of the Daito Ridges comprised the overriding plate at subduction initiation. The juxtaposition of a relatively buoyant remnant arc terrane adjacent to an oceanic plate was more favourable for subduction initiation than would have been the case if both downgoing and overriding plates had been oceanic.

  3. Effects of solid acellular type-I/III collagen biomaterials on in vitro and in vivo chondrogenesis of mesenchymal stem cells.

    Science.gov (United States)

    Gao, Liang; Orth, Patrick; Cucchiarini, Magali; Madry, Henning

    2017-09-01

    Type-I/III collagen membranes are advocated for clinical use in articular cartilage repair as being able of inducing chondrogenesis, a technique termed autologous matrix-induced chondrogenesis (AMIC). Area covered: The current in vitro and translational in vivo evidence for chondrogenic effects of solid acellular type-I/III collagen biomaterials. Expert commentary: In vitro, mesenchymal stem cells (MSCs) adhere to the fibers of the type-I/III collagen membrane. No in vitro study provides evidence that a type-I/III collagen matrix alone may induce chondrogenesis. Few in vitro studies compare the effects of type-I and type-II collagen scaffolds on chondrogenesis. Recent investigations suggest better chondrogenesis with type-II collagen scaffolds. A systematic review of the translational in vivo data identified one long-term study showing that covering of cartilage defects treated by microfracture with a type-I/III collagen membrane significantly enhanced the repair tissue volume compared with microfracture alone. Other in vivo evidence is lacking to suggest either improved histological structure or biomechanical function of the repair tissue. Taken together, there is a paucity of in vitro and preclinical in vivo evidence supporting the concept that solid acellular type-I/III collagen scaffolds may be superior to classical approaches to induce in vitro or in vivo chondrogenesis of MSCs.

  4. AUTOANTIBODIES TO THE LAMININ P1 FRAGMENT IN HGCL2-INDUCED MEMBRANOUS GLOMERULOPATHY

    NARCIS (Netherlands)

    ATEN, J; VENINGA, A; COERS, W; SONNENBERG, A; TIMPL, R; CLAESSEN, N; VANEENDENBURG, JDH; DEHEER, E; WEENING, JJ

    Exposure to mercuric chloride induces the development of a membranous glomerulopathy with high proteinuria in DZB rats, in which immunoglobulin (Ig)G1 and IgG2a bound in the glomeruli were previously found to react with laminin of the EHS tumor and several unidentified glomerular basement membrane

  5. Geology of the Pan-African basement Complex in Ube-Wulko area ...

    African Journals Online (AJOL)

    The Ube-Wulko area of southeast Akwanga falls within the Pan-African remobilized Basement Complex of northcentral Nigeria. It consists of intensely multi-deformed high grade polymetamorphic basement rocks, predominantly composed of migmatitic gneisses and schists and subordinate quartzites, marbles, and ...

  6. Basement radon entry and stack driven moisture infiltration reduced by active soil depressurization

    Science.gov (United States)

    C.R. Boardman; Samuel V. Glass

    2015-01-01

    This case study presents measurements of radon and moisture infiltration from soil gases into the basement of an unoccupied research house in Madison, Wisconsin, over two full years. The basement floor and exterior walls were constructed with preservative-treated lumber and plywood. In addition to continuous radon monitoring, measurements included building air...

  7. Basement Surface Faulting and Topography for Savannah River Site and Vicinity

    International Nuclear Information System (INIS)

    Cumbest, R.J.

    1998-01-01

    This report integrates the data from more than 60 basement borings and over 100 miles of seismic reflection profiling acquired on the Savannah River Site to map the topography of the basement (unweathered rock) surface and faulting recorded on this surface

  8. Three-Dimensional Inversion of Magnetotelluric Data for the Sediment–Basement Interface

    DEFF Research Database (Denmark)

    Cai, Hongzhu; Zhdanov, Michael

    2016-01-01

    and a resistive basement. Conventional inversions of MT data are aimed at determining the volumetric distribution of the conductivity within the inversion domain. The recovered distribution of the subsurface conductivity is typically diffusive, which makes it difficult to select the sediment-basement interface....... This letter develops a novel approach to 3-D MT inversion for the depth-to-basement estimate. The key to this approach is selection of the model parameterization, with the depth to basement being the major unknown parameter. In order to estimate the depth to the basement, the inversion algorithm recovers both...... the thickness and the conductivities of the sedimentary basin. The forward modeling is based on the integral equation approach. The inverse problem is solved using a regularized conjugate gradient method. The Fréchet derivative matrix is calculated based on quasi-Born approximation. The developed method...

  9. Ultrastructural and biochemical characterization of mechanically adaptable collagenous structures in the edible sea urchin Paracentrotus lividus.

    Science.gov (United States)

    Barbaglio, Alice; Tricarico, Serena; Ribeiro, Ana R; Di Benedetto, Cristiano; Barbato, Marta; Dessì, Desirèe; Fugnanesi, Valeria; Magni, Stefano; Mosca, Fabio; Sugni, Michela; Bonasoro, Francesco; Barbosa, Mario A; Wilkie, Iain C; Candia Carnevali, M Daniela

    2015-06-01

    The viscoelastic properties of vertebrate connective tissues rarely undergo significant changes within physiological timescales, the only major exception being the reversible destiffening of the mammalian uterine cervix at the end of pregnancy. In contrast to this, the connective tissues of echinoderms (sea urchins, starfish, sea cucumbers, etc.) can switch reversibly between stiff and compliant conditions in timescales of around a second to minutes. Elucidation of the molecular mechanism underlying such mutability has implications for the zoological, ecological and evolutionary field. Important information could also arise for veterinary and biomedical sciences, particularly regarding the pathological plasticization or stiffening of connective tissue structures. In the present investigation we analyzed aspects of the ultrastructure and biochemistry in two representative models, the compass depressor ligament and the peristomial membrane of the edible sea urchin Paracentrotus lividus, compared in three different mechanical states. The results provide further evidence that the mechanical adaptability of echinoderm connective tissues does not necessarily imply changes in the collagen fibrils themselves. The higher glycosaminoglycan (GAG) content registered in the peristomial membrane with respect to the compass depressor ligament suggests a diverse role of these molecules in the two mutable collagenous tissues. The possible involvement of GAG in the mutability phenomenon will need further clarification. During the shift from a compliant to a standard condition, significant changes in GAG content were detected only in the compass depressor ligament. Similarities in terms of ultrastructure (collagen fibrillar assembling) and biochemistry (two alpha chains) were found between the two models and mammalian collagen. Nevertheless, differences in collagen immunoreactivity, alpha chain migration on SDS-PAGE and BLAST alignment highlighted the uniqueness of sea urchin

  10. Physiological type I collagen organization induces the formation of a novel class of linear invadosomes

    Science.gov (United States)

    Juin, Amélie; Billottet, Clotilde; Moreau, Violaine; Destaing, Olivier; Albiges-Rizo, Corinne; Rosenbaum, Jean; Génot, Elisabeth; Saltel, Frédéric

    2012-01-01

    Invadosomes are F-actin structures capable of degrading the matrix through the activation of matrix metalloproteases. As fibrillar type I collagen promotes pro-matrix metalloproteinase 2 activation by membrane type 1 matrix metalloproteinase, we aimed at investigating the functional relationships between collagen I organization and invadosome induction. We found that fibrillar collagen I induced linear F-actin structures, distributed along the fibrils, on endothelial cells, macrophages, fibroblasts, and tumor cells. These structures share features with conventional invadosomes, as they express cortactin and N-WASP and accumulate the scaffold protein Tks5, which proved essential for their formation. On the basis of their ability to degrade extracellular matrix elements and their original architecture, we named these structures “linear invadosomes.” Interestingly, podosomes or invadopodia were replaced by linear invadosomes upon contact of the cells with fibrillar collagen I. However, linear invadosomes clearly differ from classical invadosomes, as they do not contain paxillin, vinculin, and β1/β3 integrins. Using knockout mouse embryonic fibroblasts and RGD peptide, we demonstrate that linear invadosome formation and activity are independent of β1 and β3 integrins. Finally, linear invadosomes also formed in a three-dimensional collagen matrix. This study demonstrates that fibrillar collagen I is the physiological inducer of a novel class of invadosomes. PMID:22114353

  11. Parametric study of effects of collagen turnover on the natural history of abdominal aortic aneurysms.

    Science.gov (United States)

    Wilson, J S; Baek, S; Humphrey, J D

    2013-02-08

    Abdominal aortic aneurysms (AAAs) are characterized by significant changes in the architecture of the aortic wall, notably, loss of functional elastin and smooth muscle. Because collagen is the principal remaining load-bearing constituent of the aneurysmal wall, its turnover must play a fundamental role in the natural history of the lesion. Nevertheless, detailed investigations of the effects of different aspects of collagen turnover on AAA development are lacking. A finite-element membrane model of the growth and remodelling of idealized AAAs was thus used to investigate parametrically four of the primary aspects of collagen turnover: rates of production, half-life, deposition stretch (prestretch) and material stiffness. The predicted rates of aneurysmal expansion and spatio-temporal changes in wall thickness, biaxial stresses and maximum collagen fibre stretch at the apex of the lesion depended strongly on all four factors, as did the predicted clinical endpoints (i.e. arrest, progressive expansion or rupture). Collagen turnover also affected the axial expansion, largely due to mechanical changes within the shoulder region of the lesion. We submit, therefore, that assessment of rupture risk could be improved by future experiments that delineate and quantify different aspects of patient-specific collagen turnover and that such understanding could lead to new targeted therapeutics.

  12. Complete Histological Resolution of Collagenous Sprue

    Directory of Open Access Journals (Sweden)

    Hugh J Freeman

    2004-01-01

    Full Text Available A 65-year-old woman developed a watery diarrhea syndrome with collagenous colitis. Later, weight loss and hypoalbuminemia were documented. This prompted small bowel biopsies that showed pathological changes of collagenous sprue. An apparent treatment response to a gluten-free diet and prednisone resulted in reduced diarrhea, weight gain and normalization of serum albumin. Later repeated biopsies from multiple small and large bowel sites over a period of over three years, however, showed reversion to normal small intestinal mucosa but persistent collagenous colitis. These results indicate that collagenous inflammatory disease may be a far more extensive process in the gastrointestinal tract than is currently appreciated. Moreover, collagenous colitis may be a clinical signal that occult small intestinal disease is present. Finally, collagenous sprue may, in some instances, be a completely reversible small intestinal disorder.

  13. Electrospun gelatin/PCL and collagen/PLCL scaffolds for vascular tissue engineering

    Directory of Open Access Journals (Sweden)

    Fu W

    2014-05-01

    Full Text Available Wei Fu,1,2,* Zhenling Liu,1,* Bei Feng,1,2 Renjie Hu,1 Xiaomin He,1 Hao Wang,1 Meng Yin,1 Huimin Huang,1 Haibo Zhang,1 Wei Wang11Department of Pediatric Cardiothoracic Surgery, 2Institute of Pediatric Translational Medicine, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China*These authors contributed equally to this workAbstract: Electrospun hybrid nanofibers prepared using combinations of natural and synthetic polymers have been widely investigated in cardiovascular tissue engineering. In this study, electrospun gelatin/polycaprolactone (PCL and collagen/poly(l-lactic acid-co-ε-caprolactone (PLCL scaffolds were successfully produced. Scanning electron micrographs showed that fibers of both membranes were smooth and homogeneous. Water contact angle measurements further demonstrated that both scaffolds were hydrophilic. To determine cell attachment and migration on the scaffolds, both hybrid scaffolds were seeded with human umbilical arterial smooth muscle cells. Scanning electron micrographs and MTT assays showed that the cells grew and proliferated well on both hybrid scaffolds. Gross observation of the transplanted scaffolds revealed that the engineered collagen/PLCL scaffolds were smoother and brighter than the gelatin/PCL scaffolds. Hematoxylin and eosin staining showed that the engineered blood vessels constructed by collagen/PLCL electrospun membranes formed relatively homogenous vessel-like tissues. Interestingly, Young's modulus for the engineered collagen/PLCL scaffolds was greater than for the gelatin/PCL scaffolds. Together, these results indicate that nanofibrous collagen/PLCL membranes with favorable mechanical and biological properties may be a desirable scaffold for vascular tissue engineering.Keywords: electrospinning, gelatin, collagen, polycaprolactone, poly(l-lactic acid-co-ε-caprolactone

  14. Permeability testing of biomaterial membranes

    Energy Technology Data Exchange (ETDEWEB)

    Dreesmann, L; Hajosch, R; Nuernberger, J Vaz; Schlosshauer, B [NMI Natural and Medical Sciences Institute at University Tuebingen, Markwiesenstr. 55, D-72770 Reutlingen (Germany); Ahlers, M [GELITA AG, Gammelsbacher Str. 2, D-69412 Eberbach (Germany)], E-mail: schlosshauer@nmi.de

    2008-09-01

    The permeability characteristics of biomaterials are critical parameters for a variety of implants. To analyse the permeability of membranes made from crosslinked ultrathin gelatin membranes and the transmigration of cells across the membranes, we combined three technical approaches: (1) a two-chamber-based permeability assay, (2) cell culturing with cytochemical analysis and (3) biochemical enzyme electrophoresis (zymography). Based on the diffusion of a coloured marker molecule in conjunction with photometric quantification, permeability data for a gelatin membrane were determined in the presence or absence of gelatin degrading fibroblasts. Cytochemical evaluation after cryosectioning of the membranes was used to ascertain whether fibroblasts had infiltrated the membrane inside. Zymography was used to investigate the potential release of proteases from fibroblasts, which are known to degrade collagen derivatives such as gelatin. Our data show that the diffusion equilibrium of a low molecular weight dye across the selected gelatin membrane is approached after about 6-8 h. Fibroblasts increase the permeability due to cavity formation in the membrane inside without penetrating the membrane for an extended time period (>21 days in vitro). Zymography indicates that cavity formation is most likely due to the secretion of matrix metalloproteinases. In summary, the combination of the depicted methods promises to facilitate a more rational development of biomaterials, because it provides a rapid means of determining permeability characteristics and bridges the gap between descriptive methodology and the mechanistic understanding of permeability alterations due to biological degradation.

  15. Permeability testing of biomaterial membranes

    International Nuclear Information System (INIS)

    Dreesmann, L; Hajosch, R; Nuernberger, J Vaz; Schlosshauer, B; Ahlers, M

    2008-01-01

    The permeability characteristics of biomaterials are critical parameters for a variety of implants. To analyse the permeability of membranes made from crosslinked ultrathin gelatin membranes and the transmigration of cells across the membranes, we combined three technical approaches: (1) a two-chamber-based permeability assay, (2) cell culturing with cytochemical analysis and (3) biochemical enzyme electrophoresis (zymography). Based on the diffusion of a coloured marker molecule in conjunction with photometric quantification, permeability data for a gelatin membrane were determined in the presence or absence of gelatin degrading fibroblasts. Cytochemical evaluation after cryosectioning of the membranes was used to ascertain whether fibroblasts had infiltrated the membrane inside. Zymography was used to investigate the potential release of proteases from fibroblasts, which are known to degrade collagen derivatives such as gelatin. Our data show that the diffusion equilibrium of a low molecular weight dye across the selected gelatin membrane is approached after about 6-8 h. Fibroblasts increase the permeability due to cavity formation in the membrane inside without penetrating the membrane for an extended time period (>21 days in vitro). Zymography indicates that cavity formation is most likely due to the secretion of matrix metalloproteinases. In summary, the combination of the depicted methods promises to facilitate a more rational development of biomaterials, because it provides a rapid means of determining permeability characteristics and bridges the gap between descriptive methodology and the mechanistic understanding of permeability alterations due to biological degradation

  16. Collagen mimetic peptide engineered M13 bacteriophage for collagen targeting and imaging in cancer.

    Science.gov (United States)

    Jin, Hyo-Eon; Farr, Rebecca; Lee, Seung-Wuk

    2014-11-01

    Collagens are over-expressed in various human cancers and subsequently degraded and denatured by proteolytic enzymes, thus making them a target for diagnostics and therapeutics. Genetically engineered bacteriophage (phage) is a promising candidate for the development of imaging or therapeutic materials for cancer collagen targeting due to its promising structural features. We genetically engineered M13 phages with two functional peptides, collagen mimetic peptide and streptavidin binding peptide, on their minor and major coat proteins, respectively. The resulting engineered phage functions as a therapeutic or imaging material to target degraded and denatured collagens in cancerous tissues. We demonstrated that the engineered phages are able to target and label abnormal collagens expressed on A549 human lung adenocarcinoma cells after the conjugation with streptavidin-linked fluorescent agents. Our engineered collagen binding phage could be a useful platform for abnormal collagen imaging and drug delivery in various collagen-related diseases. Published by Elsevier Ltd.

  17. A novel COL4A1 frameshift mutation in familial kidney disease: the importance of the C-terminal NC1 domain of type IV collagen.

    Science.gov (United States)

    Gale, Daniel P; Oygar, D Deren; Lin, Fujun; Oygar, P Derin; Khan, Nadia; Connor, Thomas M F; Lapsley, Marta; Maxwell, Patrick H; Neild, Guy H

    2016-11-01

    Hereditary microscopic haematuria often segregates with mutations of COL4A3, COL4A4 or COL4A5 but in half of families a gene is not identified. We investigated a Cypriot family with autosomal dominant microscopic haematuria with renal failure and kidney cysts. We used genome-wide linkage analysis, whole exome sequencing and cosegregation analyses. We identified a novel frameshift mutation, c.4611_4612insG:p.T1537fs, in exon 49 of COL4A1. This mutation predicts truncation of the protein with disruption of the C-terminal part of the NC1 domain. We confirmed its presence in 20 family members, 17 with confirmed haematuria, 5 of whom also had stage 4 or 5 chronic kidney disease. Eleven family members exhibited kidney cysts (55% of those with the mutation), but muscle cramps or cerebral aneurysms were not observed and serum creatine kinase was normal in all individuals tested. Missense mutations of COL4A1 that encode the CB3 [IV] segment of the triple helical domain (exons 24 and 25) are associated with HANAC syndrome (hereditary angiopathy, nephropathy, aneurysms and cramps). Missense mutations of COL4A1 that disrupt the NC1 domain are associated with antenatal cerebral haemorrhage and porencephaly, but not kidney disease. Our findings extend the spectrum of COL4A1 mutations linked with renal disease and demonstrate that the highly conserved C-terminal part of the NC1 domain of the α1 chain of type IV collagen is important in the integrity of glomerular basement membrane in humans. © The Author 2016. Published by Oxford University Press on behalf of ERA-EDTA.

  18. RESEARCH ON REDUCING PREMATURITY RUPTURE OF MEMBRANE

    OpenAIRE

    Maria URSACHI (BOLOTA); Emil ANTON; Sorana Caterina ANTON

    2016-01-01

    The membranes surrounding the amniotic cavity are composed from amnion and chorion, tightly adherent layers which are composed of several cell types, including epithelial cells, trophoblasts cells and mesenchyme cells, embedded in a collagenous matrix. They retain amniotic fluid, secret substances into the amniotic fluid, as well as to the uterus and protect the fetus against upward infections from urogenital tract. Normally, the membranes it breaks during labor. Premature rupture of the amn...

  19. Fracture mechanics of collagen fibrils

    DEFF Research Database (Denmark)

    Svensson, Rene B; Mulder, Hindrik; Kovanen, Vuokko

    2013-01-01

    technique to measure the mechanical behavior of individual collagen fibrils loaded to failure. Fibrils from human patellar tendons, rat-tail tendons (RTTs), NaBH₄ reduced RTTs, and tail tendons of Zucker diabetic fat rats were tested. We found a characteristic three-phase stress-strain behavior in the human...... and the plateau continued until failure. The importance of cross-link lability was investigated by NaBH₄ reduction of the rat-tail fibrils, which did not alter their behavior. These findings shed light on the function of cross-links at the fibril level, but further studies will be required to establish...

  20. Collagen based Biomaterials from CLRI: An Inspiration from the ...

    Indian Academy of Sciences (India)

    Focus of Research on the Collagen-based Biomaterials in CLRI: Patient care and pain reduction · People at CLRI: for Whom Collagen matters as a Biomaterial · Skin as an organ: Is it smart? Collagen: Emerging Role as a Smart material · Building blocks of Collagen based biomaterial devices · Collagen: its Organizational ...

  1. A BMP responsive transcriptional region in the chicken type X collagen gene.

    Science.gov (United States)

    Volk, S W; Luvalle, P; Leask, T; Leboy, P S

    1998-10-01

    Bone morphogenetic proteins (BMPs) were originally identified by their ability to induce ectopic bone formation and have been shown to promote both chondrogenesis and chondrocyte hypertrophy. BMPs have recently been found to activate a membrane serine/threonine kinase signaling mechanism in a variety of cell types, but the downstream effectors of BMP signaling in chondrocyte differentiation remain unidentified. We have previously reported that BMP-2 markedly stimulates type X collagen expression in prehypertrophic chick sternal chondrocytes, and that type X collagen mRNA levels in chondrocytes cultured under serum-free (SF) conditions are elevated 3- to 5-fold within 24 h. To better define the molecular mechanisms of induction of chondrocyte hypertrophy by BMPs, we examined the effect of BMPs on type X collagen production by 15-day chick embryo sternal chondrocytes cultured under SF conditions in the presence or absence of 30 ng/ml BMP-2, BMP-4, or BMP-7. Two populations of chondrocytes were used: one representing resting cartilage isolated from the caudal third of the sterna and the second representing prehypertrophic cartilage from the cephalic third of the sterna. BMP-2, BMP-4, and BMP-7 all effectively promoted chondrocyte maturation of cephalic sternal chondrocytes as measured by high levels of alkaline phosphatase, diminished levels of type II collagen, and induction of the hypertrophic chondrocyte-specific marker, type X collagen. To test whether BMP control of type X collagen expression occurs at the transcriptional level, we utilized plasmid constructs containing the chicken collagen X promoter and 5' flanking regions fused to a reporter gene. Constructs were transiently transfected into sternal chondrocytes cultured under SF conditions in the presence or absence of 30 ng/ml BMP-2, BMP-4, or BMP-7. A 533 bp region located 2.4-2.9 kb upstream from the type X collagen transcriptional start site was both necessary and sufficient for strong BMP responsiveness

  2. Membrane dynamics

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    Current topics include membrane-protein interactions with regard to membrane deformation or curvature sensing by BAR domains. Also, we study the dynamics of membrane tubes of both cells and simple model membrane tubes. Finally, we study membrane phase behavior which has important implications...

  3. Collagen XII: Protecting bone and muscle integrity by organizing collagen fibrils.

    Science.gov (United States)

    Chiquet, Matthias; Birk, David E; Bönnemann, Carsten G; Koch, Manuel

    2014-08-01

    Collagen XII, largest member of the fibril-associated collagens with interrupted triple helix (FACIT) family, assembles from three identical α-chains encoded by the COL12A1 gene. The molecule consists of three threadlike N-terminal noncollagenous NC3 domains, joined by disulfide bonds and a short interrupted collagen triple helix toward the C-terminus. Splice variants differ considerably in size and properties: "small" collagen XIIB (220 kDa subunit) is similar to collagen XIV, whereas collagen XIIA (350 kDa) has a much larger NC3 domain carrying glycosaminoglycan chains. Collagen XII binds to collagen I-containing fibrils via its collagenous domain, whereas its large noncollagenous arms interact with other matrix proteins such as tenascin-X. In dense connective tissues and bone, collagen XII is thought to regulate organization and mechanical properties of collagen fibril bundles. Accordingly, recent findings show that collagen XII mutations cause Ehlers-Danlos/myopathy overlap syndrome associated with skeletal abnormalities and muscle weakness in mice and humans. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Basement geology of Taranaki and Wanganui basins, New Zealand

    International Nuclear Information System (INIS)

    Mortimer, N.; Tulloch, A.J.; Ireland, T.R.

    1997-01-01

    We present a revised interpretation of the basement geology beneath Late Cretaceous to Cenozoic Taranaki and Wanganui basins of central New Zealand, based on new petrographic, geochemical, and geochronological data from 30 oil exploration wells. Recently published structural and magnetic interpretations of the area assist in the interpolation and extrapolation of geological boundaries. Torlesse and Waipapa terranes have been identified in Wanganui Basin, and Murihiku Terrane in eastern Taranaki Basin, but Maitai and Brook Street terrane rocks have not been recognised. Separation Point Suite, Karamea Suite, and Median Tectonic Zone igneous rocks are all identified on the basis of characteristic petrography, geochemistry, and/or age. SHRIMP U-Pb zircon measurements on igneous samples from western Taranaki wells do not give precise ages but do provide useful constraints: Motueka-1 granite is latest Devonian - earliest Carboniferous; Tangaroa-1 and Toropuihi-1 are Carboniferous; and Surville-1 is Cretaceous (cf. Separation Point Suite). Our interpretation of sub-basin geology is compatible with previously observed onland relationships in the North and South Islands. (author). 47 refs., 6 figs

  5. Laser welding and collagen crosslinks

    Energy Technology Data Exchange (ETDEWEB)

    Reiser, K.M.; Last, J.A. [California Univ., Davis, CA (United States). Dept. of Medicine; Small, W. IV; Maitland, D.J.; Heredia, N.J.; Da Silva, L.B.; Matthews, D.L. [Lawrence Livermore National Lab., CA (United States)

    1997-02-20

    Strength and stability of laser-welded tissue may be influenced, in part, by effects of laser exposure on collagen crosslinking. We therefore studied effects of diode laser exposure (805 nm, 1-8 watts, 30 seconds) + indocyanine green dye (ICG) on calf tail tendon collagen crosslinks. Effect of ICG dye alone on crosslink content prior to laser exposure was investigated; unexpectedly, we found that ICG-treated tissue had significantly increased DHLNL and OHP, but not HLNL. Laser exposure after ICG application reduced elevated DHLNL and OHP crosslink content down to their native levels. The monohydroxylated crosslink HLNL was inversely correlated with laser output (p<0.01 by linear regression analysis). DHLNL content was highly correlated with content of its maturational product, OHP, suggesting that precursor-product relations are maintained. We conclude that: (1)ICG alone induces DHLNL and OHP crosslink formation; (2)subsequent laser exposure reduces the ICG-induced crosslinks down to native levels; (3)excessive diode laser exposure destroys normally occurring HLNL crosslinks.

  6. Depth of magnetic basement in Iran based on fractal spectral analysis of aeromagnetic data

    Science.gov (United States)

    Teknik, Vahid; Ghods, Abdolreza

    2017-06-01

    To estimate the shape of sedimentary basins, a critical parameter in hydrocarbon exploration, we calculated the depth of magnetic basement by applying a fractal spectral method to the aeromagnetic map of Iran. The depth of magnetic basement is a close proxy for the shape of sedimentary basins provided that igneous basement is strongly magnetized relative to the overlying sediments and there is no interbedding magnetic layer in the sediments. The shape of the power spectrum of magnetic anomalies is sensitive to the depth of magnetic basement, the thickness of the magnetic layer, the fractal parameter of magnetization and the size of the window used for the calculation of the power spectrum. Using a suite of synthetic tests, we have shown that the estimation of the depth of magnetic basement of up to 20 km is not very sensitive to the often unknown fractal parameter and thus the spectral method is a reliable tool to calculate the depth of magnetic basement. The depth of magnetic basement is in the range of 7-16 km in the Zagros, east Alborz, Tabas, Jazmurian and Makran regions, showing a close correlation with depths estimated from the maximum thickness of stratigraphic columns. We have also found new sedimentary basins in Bostan Abad, Bijar and south of Orumiyeh Lake. The significant depth of the magnetic basement in the Makran, Jazmurain depression, southeast Caspian Sea, Tabas, Great Kavir, south of Orumiyeh Lake, Bostan Abad and Bijar sedimentary basins makes them future prospects for hydrocarbon explorations. The depth of magnetic basement is strongly reduced over the Neyriz and Kermanshah Ophiolites, but it does not show any meaningful correlation with other outcrops of ophiolitic rocks in Iran.

  7. Novel bioresorbable strontium hydroxyapatite membrane for guided bone regeneration.

    Science.gov (United States)

    Hao, J; Acharya, A; Chen, K; Chou, J; Kasugai, S; Lang, N P

    2015-01-01

    Membrane materials have been widely used for guided bone regeneration (GBR). However, due to bio-functional limitation of the current membranes, the ideal resorbable membrane that can stimulate bone regeneration has yet to be developed. This study seeks to investigate the effects of a strontium hydroxyapatite (SrHA)-containing membrane for GBR. Strontium hydroxyapatite powder was synthesized and mixed with gelatin solution to the final concentration of 10 mg/ml (Sr10) and 20 mg/ml (Sr20). Approximately 100-μm-thick membranes were fabricated, and the mechanical properties and strontium ion release pattern were analyzed. Rat bone marrow stromal cell (BMSC) responses were investigated in vitro. Bilaterial rat calvarial defects were used in vivo to compare the SrHA membranes against commercially available collagen membranes and evaluated radiologically and histologically. Strontium hydroxyapatite membranes exhibited higher elasticity and strength than the collagen membrane, and slow strontium ion release was also confirmed. No BMSC cytotoxicity was found on the SrHA membranes, and the alkaline phosphatase positively stained area was significantly greater than the collagen membrane at earlier time point. At 4 weeks, both micro-CT and histological analyses revealed that the Sr20 group yielded significantly greater bone formation. The SrHA-containing membrane developed in this study was found to be a biocompatible material that can stimulate BMSC differentiation as well as bone regeneration and maturation in rat calvarial defects at early time point compared with collagen membrane. The best result was observed in Sr20 group, which can be potentially effective for GBR. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Preventive and therapeutic effects of antler collagen on osteoporosis ...

    African Journals Online (AJOL)

    MTPS) were observed in antler collagen-treated groups. The extracted collagen was found to play a role in the prevention and treatment of osteoporosis in ovariectomized rats. Key words: Antler, collagen, osteoporosis, preventive, therapeutic ...

  9. Exploiting oleuropein for inhibiting collagen fibril formation.

    Science.gov (United States)

    Bharathy, H; Fathima, N Nishad

    2017-08-01

    Collagen fibrils accumulate in excessive amounts and impair the normal functioning of the organ; therefore it stimulates the interest for identifying the compounds that could prevent the formation of fibrils. Herein, inhibition of self-assembly of collagen using oleuropein has been studied. The changes in the physico-chemical characteristics of collagen on interaction with increasing concentration of oleuropein has been studied using techniques like viscosity, UV-vis, CD and FT-IR. The inhibitory effect of oleuropein on fibril formation of collagen was proved using SEM. Circular dichroism and FT-IR spectra elucidates the alterations in the secondary structure of collagen suggesting non-covalent interactions between oleuropein and collagen. The decreased rate of collagen fibril formation also confirms the inhibition in the self-assembly of collagen. Hence, our study suggests that inhibition of the self-assembly process using oleuropein may unfold new avenues to treat fibrotic diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Glycine functionalized alumina nanoparticles stabilize collagen in ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... ... with collagen fibres was demonstrated using HRSEM, EDX, differential scanning calorimetry and FT-IR analysis. The thermal stability of collagen is enhanced to 74°C upon interaction with Gly@Al2O3 nanoparticles thereby suggesting applications in leather making, biomedicine and cosmetic fields.

  11. Imaging Prostate Cancer Microenvironment by Collagen Hybridization

    Science.gov (United States)

    2013-10-01

    Scl2.28CL, derived from the cell-surface protein (Scl2) of Streptococcus pyogenes previously reported to form collagen-like triple helices.37 The...Self-association of streptococcus pyogenes collagen-like constructs into higher order structures. Protein Sci. 18, 1241−1251. (44) Bac̈hinger, H. P

  12. Glycine functionalized alumina nanoparticles stabilize collagen in ...

    Indian Academy of Sciences (India)

    perse well in organic solvents rather than in water. SiO2 nanoparticles were used to crosslink the collagen and enhance the thermal stability significantly [14]. The use of functionalized iron oxide nanoparticles for collagen stabi- lization both in aqueous and non-aqueous media was in recent times [15,16]. Castaneda et al ...

  13. A novel functional role of collagen glycosylation

    DEFF Research Database (Denmark)

    Jürgensen, Henrik J; Madsen, Daniel H; Ingvarsen, Signe

    2011-01-01

    , the function of which is poorly known. The endocytic collagen receptor urokinase plasminogen activator receptor-associated protein (uPARAP)/Endo180 plays an important role in matrix remodeling through its ability to internalize collagen for lysosomal degradation. uPARAP/Endo180 is a member of the mannose....... The molecular basis for this interaction is known to involve the fibronectin type II domain but nothing is known about the function of the lectin domains in this respect. In this study, we have investigated a possible role of the single active lectin domain of uPARAP/Endo180 in the interaction with collagens....... By expressing truncated recombinant uPARAP/Endo180 proteins and analyzing their interaction with collagens with high and low levels of glycosylation we demonstrated that this lectin domain interacts directly with glycosylated collagens. This interaction is functionally important because it was found to modulate...

  14. Chondroitin Sulfate Perlecan Enhances Collagen Fibril Formation

    DEFF Research Database (Denmark)

    Kvist, A. J.; Johnson, A. E.; Mörgelin, M.

    2006-01-01

    in collagen type II fibril assembly by perlecan-null chondrocytes. Cartilage perlecan is a heparin sulfate or a mixed heparan sulfate/chondroitin sulfate proteoglycan. The latter form binds collagen and accelerates fibril formation in vitro, with more defined fibril morphology and increased fibril diameters...... produced in the presence of perlecan. Interestingly, the enhancement of collagen fibril formation is independent on the core protein and is mimicked by chondroitin sulfate E but neither by chondroitin sulfate D nor dextran sulfate. Furthermore, perlecan chondroitin sulfate contains the 4,6-disulfated...... disaccharides typical for chondroitin sulfate E. Indeed, purified glycosaminoglycans from perlecan-enriched fractions of cartilage extracts contain elevated levels of 4,6-disulfated chondroitin sulfate disaccharides and enhance collagen fibril formation. The effect on collagen assembly is proportional...

  15. Determination of collagen fibril size via absolute measurements of second-harmonic generation signals

    Science.gov (United States)

    Bancelin, Stéphane; Aimé, Carole; Gusachenko, Ivan; Kowalczuk, Laura; Latour, Gaël; Coradin, Thibaud; Schanne-Klein, Marie-Claire

    2014-09-01

    The quantification of collagen fibril size is a major issue for the investigation of pathological disorders associated with structural defects of the extracellular matrix. Second-harmonic generation microscopy is a powerful technique to characterize the macromolecular organization of collagen in unstained biological tissues. Nevertheless, due to the complex coherent building of this nonlinear optical signal, it has never been used to measure fibril diameter so far. Here we report absolute measurements of second-harmonic signals from isolated fibrils down to 30 nm diameter, via implementation of correlative second-harmonic-electron microscopy. Moreover, using analytical and numerical calculations, we demonstrate that the high sensitivity of this technique originates from the parallel alignment of collagen triple helices within fibrils and the subsequent constructive interferences of second-harmonic radiations. Finally, we use these absolute measurements as a calibration for ex vivo quantification of fibril diameter in the Descemet’s membrane of a diabetic rat cornea.

  16. Guided bone regeneration in rat mandibular defects using resorbable poly(trimethylene carbonate) barrier membranes

    NARCIS (Netherlands)

    van Leeuwen, A.C.; Huddelston Slater, J.J.R.; Gielkens, P.F.M.; de Jong, J.R.; Grijpma, Dirk W.; Bos, R.R.M.

    2012-01-01

    The present study evaluates a new synthetic degradable barrier membrane based on poly(trimethylene carbonate) (PTMC) for use in guided bone regeneration. A collagen membrane and an expanded polytetrafluoroethylene (e-PTFE) membrane served as reference materials. In 192 male Sprague–Dawley rats, a

  17. Guided bone regeneration in rat mandibular defects using resorbable poly(trimethylene carbonate) barrier membranes

    NARCIS (Netherlands)

    van Leeuwen, A. C.; Huddleston Slater, J. J. R.; Gielkens, P. F. M.; de Jong, J. R.; Grijpma, D. W.; Bos, R. R. M.

    The present study evaluates a new synthetic degradable barrier membrane based on poly(trimethylene carbonate) (PTMC) for use in guided bone regeneration. A collagen membrane and an expanded polytetrafluoroethylene (e-PTFE) membrane served as reference materials. In 192 male Sprague-Dawley rats, a

  18. Collagen Structure of Tendon Relates to Function

    Directory of Open Access Journals (Sweden)

    Marco Franchi

    2007-01-01

    Full Text Available A tendon is a tough band of fibrous connective tissue that connects muscle to bone, designed to transmit forces and withstand tension during muscle contraction. Tendon may be surrounded by different structures: 1 fibrous sheaths or retinaculae; 2 reflection pulleys; 3 synovial sheaths; 4 peritendon sheaths; 5 tendon bursae. Tendons contain a few cells, mostly represented by tenoblasts along with endothelial cells and some chondrocytes; b proteoglycans (PGs, mainly decorin and hyaluronan, and c collagen, mostly type I. Tendon is a good example of a high ordered extracellular matrix in which collagen molecules assemble into filamentous collagen fibrils (formed by microfibrils which aggregate to form collagen fibers, the main structural components. It represents a multihierarchical structure as it contains collagen molecules arranged in fibrils then grouped in fibril bundles, fascicles and fiber bundles that are almost parallel to the long axis of the tendon, named as primary, secondary and tertiary bundles. Collagen fibrils in tendons show prevalently large diameter, a D-period of about 67 nm and appear built of collagen molecules lying at a slight angle (< 5°. Under polarized light microscopy the collagen fiber bundles appear crimped with alternative dark and light transverse bands. In recent studies tendon crimps observed via SEM and TEM show that the single collagen fibrils suddenly changing their direction contain knots. These knots of collagen fibrils inside each tendon crimp have been termed “fibrillar crimps”, and even if they show different aspects they all may fulfil the same functional role. As integral component of musculoskeletal system, the tendon acts to transmit muscle forces to the skeletal system. There is no complete understanding of the mechanisms in transmitting/absorbing tensional forces within the tendon; however it seems likely that a flattening of tendon crimps may occur at a first stage of tendon stretching

  19. Modeling Spatial and Temporal Fault Zone Evolution in Basement Rocks

    Science.gov (United States)

    Lunn, R. J.; Moir, H.; Shipton, Z. K.; Willson, J. P.

    2007-05-01

    There is considerable industrial interest in assessing the permeability of faults for the purpose of oil and gas production, deep well injection of waste liquids, underground storage of natural gas and disposal of radioactive waste. Deterministic prior estimation of fault hydraulic properties is highly error prone. Faults zones are formed through a complex interaction of mechanical, hydraulic and chemical processes and their permeability varies considerably over both space and time. Algorithms for predicting fault seal potential using throw and host rock property data exist for clay-rich fault seals but are contentious. In the case of crystalline rocks and sand-sand contacts, no such algorithms exist. In any case, the study of fault growth processes does not suggest that there is a clear or simple relationship between fault throw and the fault zone permeability. To improve estimates of fault zone permeability, it is important to understand the underlying hydro-mechanical processes of fault zone formation. In this research, we explore the spatial and temporal evolution of fault zones through development and application of a 2D hydro-mechanical finite element model. The temporal development of fault zone damage is simulated perpendicular to the main slip surface using Navier's equation for mechanical deformation. The model is applied to study development of fault zones in basement rocks. We simulate the evolution of fault zones from pre-existing joints and explore controls on the growth rate and locations of multiple splay fractures which link-up to form complex damage zones. We explore the temporal evolution of the stress field surrounding the fault tip for both propagation of isolated small faults and for fault linkage Results from these simulations have been validated using outcrop data.

  20. Fault distribution in the Precambrian basement of South Norway

    Science.gov (United States)

    Gabrielsen, Roy H.; Nystuen, Johan Petter; Olesen, Odleiv

    2018-03-01

    Mapping of the structural pattern by remote sensing methods (Landsat, SPOT, aerial photography, potential field data) and field study of selected structural elements shows that the cratonic basement of South Norway is strongly affected by a regular lineament pattern that encompasses fault swarms of different orientation, age, style, attitude and frequency. Albeit counting numerous fault and fracture populations, the faults are not evenly distributed and N-S to NNE-SSW/NNW-SSE and NE-SE/ENE-WSW-systems are spatially dominant. N-S to NNW-SSE structures can be traced underneath the Caledonian nappes to the Western Gneiss Region in western and central South Norway, emphasizing their ancient roots. Dyke swarms of different ages are found within most of these zones. Also, the Østfold, Oslo-Trondheim and the Mandal-Molde lineament zones coincide with trends of Sveconorwegian post-collision granites. We conclude that the N-S-trend includes the most ancient structural elements, and that the trend can be traced back to the Proterozoic (Svecofennian and Sveconorwegian) orogenic events. Some of the faults may have been active in Neoproterozoic times as marginal faults of rift basins at the western margin of Baltica. Remnants of such fault activity have survived in the cores of many of the faults belonging to this system. The ancient systems of lineaments were passively overridden by the Caledonian fold-and-thrust system and remained mostly, but note entirely inactive throughout the Sub-Cambrian peneplanation and the Caledonian orogenic collapse in the Silurian-Devonian. The system was reactivated in extension from Carboniferous times, particularly in the Permian with the formation of the Oslo Rift and parts of it remain active to the Present, albeit by decreasing extension and fault activity.

  1. Protein nanocoatings on synthetic polymeric nanofibrous membranes designed as carriers for skin cells.

    Science.gov (United States)

    Bacakova, Marketa; Pajorova, Julia; Stranska, Denisa; Hadraba, Daniel; Lopot, Frantisek; Riedel, Tomas; Brynda, Eduard; Zaloudkova, Margit; Bacakova, Lucie

    2017-01-01

    Protein-coated resorbable synthetic polymeric nanofibrous membranes are promising for the fabrication of advanced skin substitutes. We fabricated electrospun polylactic acid and poly(lactide- co -glycolic acid) nanofibrous membranes and coated them with fibrin or collagen I. Fibronectin was attached to a fibrin or collagen nanocoating, in order further to enhance the cell adhesion and spreading. Fibrin regularly formed a coating around individual nanofibers in the membranes, and also formed a thin noncontinuous nanofibrous mesh on top of the membranes. Collagen also coated most of the fibers of the membrane and randomly created a soft gel on the membrane surface. Fibronectin predominantly adsorbed onto a thin fibrin mesh or a collagen gel, and formed a thin nanofibrous structure. Fibrin nanocoating greatly improved the attachment, spreading, and proliferation of human dermal fibroblasts, whereas collagen nanocoating had a positive influence on the behavior of human HaCaT keratinocytes. In addition, fibrin stimulated the fibroblasts to synthesize fibronectin and to deposit it as an extracellular matrix. Fibrin coating also showed a tendency to improve the ultimate tensile strength of the nanofibrous membranes. Fibronectin attached to fibrin or to a collagen coating further enhanced the adhesion, spreading, and proliferation of both cell types.

  2. Characteristics of the crystalline basement beneath the Ordos Basin: Constraint from aeromagnetic data

    Directory of Open Access Journals (Sweden)

    Zhentao Wang

    2015-05-01

    Full Text Available Aeromagnetic anomaly zonation of the Ordos Basin and adjacent areas was obtained by processing high-precision and large-scale aeromagnetic anomalies with an approach of reduction to the pole upward continuation. Comparative study on aeromagnetic and seismic tomography suggests that aeromagnetic anomalies in this area are influenced by both the magnetic property of the rock and the burial depth of the Precambrian crystalline basement. Basement depth might be the fundamental control factor for aeromagnetic anomalies because the positive and negative anomalies on the reduction to the pole-upward-continuation anomaly maps roughly coincide with the uplifts and depressions of the crystalline basement in the basin. The results, together with the latest understanding of basement faults, SHRIMP U-Pb zircon dating of metamorphic rock and granite, drilling data, detrital zircon ages, and gravity data interpretation, suggest that the Ordos block is not an entirety of Archean.

  3. Dynamic culture of a thermosensitive collagen hydrogel as an extracellular matrix improves the construction of tissue-engineered peripheral nerve.

    Science.gov (United States)

    Huang, Lanfeng; Li, Rui; Liu, Wanguo; Dai, Jin; Du, Zhenwu; Wang, Xiaonan; Ma, Jianchao; Zhao, Jinsong

    2014-07-15

    Tissue engineering technologies offer new treatment strategies for the repair of peripheral nerve injury, but cell loss between seeding and adhesion to the scaffold remains inevitable. A thermosensitive collagen hydrogel was used as an extracellular matrix in this study and combined with bone marrow mesenchymal stem cells to construct tissue-engineered peripheral nerve composites in vitro. Dynamic culture was performed at an oscillating frequency of 0.5 Hz and 35° swing angle above and below the horizontal plane. The results demonstrated that bone marrow mesenchymal stem cells formed membrane-like structures around the poly-L-lactic acid scaffolds and exhibited regular alignment on the composite surface. Collagen was used to fill in the pores, and seeded cells adhered onto the poly-L-lactic acid fibers. The DNA content of the bone marrow mesenchymal stem cells was higher in the composites constructed with a thermosensitive collagen hydrogel compared with that in collagen I scaffold controls. The cellular DNA content was also higher in the thermosensitive collagen hydrogel composites constructed with the thermosensitive collagen hydrogel in dynamic culture than that in static culture. These results indicate that tissue-engineered composites formed with thermosensitive collagen hydrogel in dynamic culture can maintain larger numbers of seeded cells by avoiding cell loss during the initial adhesion stage. Moreover, seeded cells were distributed throughout the material.

  4. Changes in collagenous tissue microstructures and distributions of cathepsin L in body wall of autolytic sea cucumber (Stichopus japonicus).

    Science.gov (United States)

    Liu, Yu-Xin; Zhou, Da-Yong; Ma, Dong-Dong; Liu, Yan-Fei; Li, Dong-Mei; Dong, Xiu-Ping; Tan, Ming-Qian; Du, Ming; Zhu, Bei-Wei

    2016-12-01

    The autolysis of sea cucumber (Stichopus japonicus) was induced by ultraviolet (UV) irradiation, and the changes of microstructures of collagenous tissues and distributions of cathepsin L were investigated using histological and histochemical techniques. Intact collagen fibers in fresh S. japonicus dermis were disaggregated into collagen fibrils after UV stimuli. Cathepsin L was identified inside the surface of vacuoles in the fresh S. japonicus dermis cells. After the UV stimuli, the membranes of vacuoles and cells were fused together, and cathepsin L was released from cells and diffused into tissues. The density of cathepsin L was positively correlated with the speed and degree of autolysis in different layers of body wall. Our results revealed that lysosomal cathepsin L was released from cells in response to UV stimuli, which contacts and degrades the extracellular substrates such as collagen fibers, and thus participates in the autolysis of S. japonicus. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Membrane fusion

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    At Stanford University, Boxer lab, I worked on membrane fusion of small unilamellar lipid vesicles to flat membranes tethered to glass surfaces. This geometry closely resembles biological systems in which liposomes fuse to plasma membranes. The fusion mechanism was studied using DNA zippering...... between complementary strands linked to the two apposing membranes closely mimicking the zippering mechanism of SNARE fusion complexes....

  6. Biobased Membrane

    NARCIS (Netherlands)

    Koenders, E.A.B.; Zlopasa, J.; Picken, S.J.

    2015-01-01

    The present invention is in the field of a composition for forming a bio-compatible membrane applicable to building material, such as concrete, cement, etc., to a meth od of applying said composition for forming a bio-compatible membrane, a biocompatible membrane, use of said membrane for various

  7. Contribution To The Geology Of Basement Rocks In The South Western Desert Of Egypt

    International Nuclear Information System (INIS)

    Sadek, M.F.; Khyamy, A.A.

    2003-01-01

    Three major Precambrian basement inliers are exposed in the South Western Desert of Egypt between Long. 29 degree E and the River Nile within the Uweinat-Bir Safsaf-Aswan E-W uplift system. These are Bir Safsaf, Gabal EI-Asr and Gabal Umm Shaghir areas. Smaller outcrops include Gabal EI-Gara El-Hamra and Gabal El-Gara EI-Soda, Gabal Siri, GabaI EI-Fantas and Aswan-Kalabsha area as well as the scattered outcrops around Darb El-Arbain road. Band ratios 5/7, 5/1, 4 of Landsat TM images were applied to delineate the borders, the lithologic units and structural features of low relief basement outcrops within the surrounding flat lying sedimentary rocks and sand plains. These basement rocks comprise ortho gneisses (assumed by many authors as related to old continent pre Pan-African rocks), G 1 tonalite-granodiorite, and G2 monzogranite-alkali feldspar granite intruded by variable dykes. The boundaries between the basement exposures and the sedimentary rocks are marked by nonconformity surfaces or sets of faults. Both basement and sedimentary rocks are intruded by Mesozoic syenite-G3 granites, rhyolite, trachytic plugs and Upper Cretaceous to Tertiary basalts. The basement exposures are structurally controlled by major E- W fault systems. Their vertical uplifting is overprinted by folding the overlying sedimentary rocks. This study revealed that, the different basement exposures in the SE of the Western Desert of Egypt are similar in appearance and field relations to the Pan-African basement rocks extending towards the east of the River Nile and exposed everywhere in the Eastern Desert of Egypt

  8. Guided Bone Regeneration Using Collagen Scaffolds, Growth Factors, and Periodontal Ligament Stem Cells for Treatment of Peri-Implant Bone Defects In Vivo

    Directory of Open Access Journals (Sweden)

    Peer W. Kämmerer

    2017-01-01

    Full Text Available Introduction. The aim of the study was an evaluation of different approaches for guided bone regeneration (GBR of peri-implant defects in an in vivo animal model. Materials and Methods. In minipigs (n=15, peri-implant defects around calcium phosphate- (CaP-; n=46 coated implants were created and randomly filled with (1 blank, (2 collagen/hydroxylapatite/β-tricalcium phosphate scaffold (CHT, (3 CHT + growth factor cocktail (GFC, (4 jellyfish collagen matrix, (5 jellyfish collagen matrix + GFC, (6 collagen powder, and (7 collagen powder + periodontal ligament stem cells (PDLSC. Additional collagen membranes were used for coverage of the defects. After 120 days of healing, bone growth was evaluated histologically (bone to implant contact (BIC;%, vertical bone apposition (VBA; mm, and new bone height (NBH; %. Results. In all groups, new bone formation was seen. Though, when compared to the blank group, no significant differences were detected for all parameters. BIC and NBH in the group with collagen matrix as well as the group with the collagen matrix + GFC were significantly less when compared to the collagen powder group (all: p<0.003. Conclusion. GBR procedures, in combination with CaP-coated implants, will lead to an enhancement of peri-implant bone growth. There was no additional significant enhancement of osseous regeneration when using GFC or PDLSC.

  9. Flightless I interacts with NMMIIA to promote cell extension formation, which enables collagen remodeling

    Science.gov (United States)

    Arora, Pamma D.; Wang, Yongqiang; Bresnick, Anne; Janmey, Paul A.; McCulloch, Christopher A.

    2015-01-01

    We examined the role of the actin-capping protein flightless I (FliI) in collagen remodeling by mouse fibroblasts. FliI-overexpressing cells exhibited reduced spreading on collagen but formed elongated protrusions that stained for myosin10 and fascin and penetrated pores of collagen-coated membranes. Inhibition of Cdc42 blocked formation of cell protrusions. In FliI-knockdown cells, transfection with constitutively active Cdc42 did not enable protrusion formation. FliI-overexpressing cells displayed increased uptake and degradation of exogenous collagen and strongly compacted collagen fibrils, which was blocked by blebbistatin. Mass spectrometry analysis of FliI immunoprecipitates showed that FliI associated with nonmuscle myosin IIA (NMMIIA), which was confirmed by immunoprecipitation. GFP-FliI colocalized with NMMIIA at cell protrusions. Purified FliI containing gelsolin-like domains (GLDs) 1–6 capped actin filaments efficiently, whereas FliI GLD 2–6 did not. Binding assays showed strong interaction of purified FliI protein (GLD 1–6) with the rod domain of NMMIIA (kD = 0.146 μM), whereas FliI GLD 2–6 showed lower binding affinity (kD = 0.8584 μM). Cells expressing FliI GLD 2–6 exhibited fewer cell extensions, did not colocalize with NMMIIA, and showed reduced collagen uptake compared with cells expressing FliI GLD 1–6. We conclude that FliI interacts with NMMIIA to promote cell extension formation, which enables collagen remodeling in fibroblasts. PMID:25877872

  10. The morphology and nature of the East Arctic ocean acoustic basement

    Science.gov (United States)

    Rekant, Pavel

    2017-04-01

    As the result of the thorough interpretation and cross-correlation of the large seismic dataset (>150000 km and >600 seismic lines), the depth structure map of the acoustic basement was constrained. Tectonic framework, basement surface morphology and linkage of the deep basin structures with shelves ones, was significantly clarified based on the map. It becomes clear that most morphostructures presently located within deep-water basin are tectonically connected with shelf structures. Acoustic basement contains a number of pre-Cambrian, Caledonian and Mesozoic consolidated blocks. The basement heterogeneity is highlighted by faults framework and basement surface morphology differences, as well thickness and stratigraphy of the sediment cover. The deepest basins of the East Arctic - Hanna Trough, North Chukchi and Podvodnikov Basins form a united mega-depression, wedged between pre-Cambrian continental blocks (Chukchi Borderland - Mendeleev Rise - Toll Saddle) from the north and the Caledonian deformation front from the south. The basement age/origin speculations are consistent with paleontological and U-Pb zircon ages from dredged rock samples. Most of morphological boundaries in the modern Arctic differ considerably from the tectonic framework. Only part of the Arctic morphostructures is constrained by tectonic boundaries. They are: eastern slope of the Lomonosov Ridge, continental slope in the Laptev Sea, upper continental slope in the Podvodnikov Basin, southern slope of the North Chukchi Basin and borders of the Chukchi Borderland. The rest significant part of modern morphological boundaries are caused by sedimentation processes.

  11. Age Increases Monocyte Adhesion on Collagen

    Science.gov (United States)

    Khalaji, Samira; Zondler, Lisa; Kleinjan, Fenneke; Nolte, Ulla; Mulaw, Medhanie A.; Danzer, Karin M.; Weishaupt, Jochen H.; Gottschalk, Kay-E.

    2017-05-01

    Adhesion of monocytes to micro-injuries on arterial walls is an important early step in the occurrence and development of degenerative atherosclerotic lesions. At these injuries, collagen is exposed to the blood stream. We are interested whether age influences monocyte adhesion to collagen under flow, and hence influences the susceptibility to arteriosclerotic lesions. Therefore, we studied adhesion and rolling of human peripheral blood monocytes from old and young individuals on collagen type I coated surface under shear flow. We find that firm adhesion of monocytes to collagen type I is elevated in old individuals. Pre-stimulation by lipopolysaccharide increases the firm adhesion of monocytes homogeneously in older individuals, but heterogeneously in young individuals. Blocking integrin αx showed that adhesion of monocytes to collagen type I is specific to the main collagen binding integrin αxβ2. Surprisingly, we find no significant age-dependent difference in gene expression of integrin αx or integrin β2. However, if all integrins are activated from the outside, no differences exist between the age groups. Altered integrin activation therefore causes the increased adhesion. Our results show that the basal increase in integrin activation in monocytes from old individuals increases monocyte adhesion to collagen and therefore the risk for arteriosclerotic plaques.

  12. Cosmetic Potential of Marine Fish Skin Collagen

    Directory of Open Access Journals (Sweden)

    Ana L. Alves

    2017-10-01

    Full Text Available Many cosmetic formulations have collagen as a major component because of its significant benefits as a natural humectant and moisturizer. This industry is constantly looking for innovative, sustainable, and truly efficacious products, so marine collagen based formulations are arising as promising alternatives. A solid description and characterization of this protein is fundamental to guarantee the highest quality of each batch. In the present study, we present an extensive characterization of marine-derived collagen extracted from salmon and codfish skins, targeting its inclusion as component in cosmetic formulations. Chemical and physical characterizations were performed using several techniques such as sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE, Fourier Transformation Infrared (FTIR spectroscopy rheology, circular dichroism, X-ray diffraction, humidity uptake, and a biological assessment of the extracts regarding their irritant potential. The results showed an isolation of type I collagen with high purity but with some structural and chemical differences between sources. Collagen demonstrated a good capacity to retain water, thus being suitable for dermal applications as a moisturizer. A topical exposure of collagen in a human reconstructed dermis, as well as the analysis of molecular markers for irritation and inflammation, exhibited no irritant potential. Thus, the isolation of collagen from fish skins for inclusion in dermocosmetic applications may constitute a sustainable and low-cost platform for the biotechnological valorization of fish by-products.

  13. Nanoscale Mechanics of Type I Collagen

    Science.gov (United States)

    Harper, H.; Cropper, E.; Bulger, A.; Choksi, U.; Koob, T. J.; Pandit, S.; Matthews, W. G.

    2009-03-01

    Collagen is the most abundant protein in the body by mass. Type I collagen fibrils provide mechanical strength and cellular housing within tissues exhibiting a broad range of mechanical properties. This diversity in the mechanics of tissues with similar underlying components warrants detailed study of the process by which structure and mechanics develop. While collagen mechanics have been studied at the tissue level for decades, surprising little is known about collagen mechanics at the fibril and molecular level. Presented herein is a multi-scale experimental and computational investigation of collagen I mechanics, bridging the single molecule and fibril hierarchal forms. The mechanics of single collagen molecules are explored using AFM and force spectroscopy. Moreover, atomistic molecular-dynamics simulations are performed to provide structural information not accessible to the experimental system. Fibrils then are grown from molecular collagen, and the mechanics of these fibrils are investigated using AFM. Based upon the single molecule and fibril results, a coarse-grain computational model is being developed. The outcomes include a better understanding of how the mechanics of filamentous self-organizing systems are derived and how their hierarchical forms are established.

  14. Association of collagen architecture with glioblastoma patient survival.

    Science.gov (United States)

    Pointer, Kelli B; Clark, Paul A; Schroeder, Alexandra B; Salamat, M Shahriar; Eliceiri, Kevin W; Kuo, John S

    2017-06-01

    OBJECTIVE Glioblastoma (GBM) is the most malignant primary brain tumor. Collagen is present in low amounts in normal brain, but in GBMs, collagen gene expression is reportedly upregulated. However, to the authors' knowledge, direct visualization of collagen architecture has not been reported. The authors sought to perform the first direct visualization of GBM collagen architecture, identify clinically relevant collagen signatures, and link them to differential patient survival. METHODS Second-harmonic generation microscopy was used to detect collagen in a GBM patient tissue microarray. Focal and invasive GBM mouse xenografts were stained with Picrosirius red. Quantitation of collagen fibers was performed using custom software. Multivariate survival analysis was done to determine if collagen is a survival marker for patients. RESULTS In focal xenografts, collagen was observed at tumor brain boundaries. For invasive xenografts, collagen was intercalated with tumor cells. Quantitative analysis showed significant differences in collagen fibers for focal and invasive xenografts. The authors also found that GBM patients with more organized collagen had a longer median survival than those with less organized collagen. CONCLUSIONS Collagen architecture can be directly visualized and is different in focal versus invasive GBMs. The authors also demonstrate that collagen signature is associated with patient survival. These findings suggest that there are collagen differences in focal versus invasive GBMs and that collagen is a survival marker for GBM.

  15. Characterization of Genipin-Modified Dentin Collagen

    Directory of Open Access Journals (Sweden)

    Hiroko Nagaoka

    2014-01-01

    Full Text Available Application of biomodification techniques to dentin can improve its biochemical and biomechanical properties. Several collagen cross-linking agents have been reported to strengthen the mechanical properties of dentin. However, the characteristics of collagen that has undergone agent-induced biomodification are not well understood. The objective of this study was to analyze the effects of a natural cross-linking agent, genipin (GE, on dentin discoloration, collagen stability, and changes in amino acid composition and lysyl oxidase mediated natural collagen cross-links. Dentin collagen obtained from extracted bovine teeth was treated with three different concentrations of GE (0.01%, 0.1%, and 0.5% for several treatment times (0–24 h. Changes in biochemical properties of NaB3H4-reduced collagen were characterized by amino acid and cross-link analyses. The treatment of dentin collagen with GE resulted in a concentration- and time-dependent pigmentation and stability against bacterial collagenase. The lysyl oxidase-mediated trivalent mature cross-link, pyridinoline, showed no difference among all groups while the major divalent immature cross-link, dehydro-dihydroxylysinonorleucine/its ketoamine in collagen treated with 0.5% GE for 24 h, significantly decreased compared to control (P< 0.05. The newly formed GE-induced cross-links most likely involve lysine and hydroxylysine residues of collagen in a concentration-dependent manner. Some of these cross-links appear to be reducible and stabilized with NaB3H4.

  16. Modelling Spatial and Temporal Fault Zone Evolution in Basement Rocks

    Science.gov (United States)

    Lunn, R. J.; Willson, J. P.; Shipton, Z. K.

    2006-12-01

    There is considerable industrial interest in assessing the permeability of faults for the purpose of oil and gas production, deep well injection of waste liquids, underground storage of natural gas and disposal of radioactive waste. Prior estimation of fault hydraulic properties is highly error prone. Faults zones are formed through a complex interaction of mechanical, hydraulic and chemical processes and their permeability varies considerably over both space and time. Algorithms for predicting fault seal potential using throw and host rock property data exist for clay-rich fault seals but are contentious. In the case of crystalline rocks and sand-sand contacts, no such algorithms exist. In any case, the study of fault growth processes does not suggest that there is a clear or simple relationship between fault throw and the fault zone permeability. To improve estimates of fault zone permeability, it is important to understand the underlying hydro-mechanical processes of fault zone formation. In this research, we explore the spatial and temporal evolution of fault zones through development and application of a 2D hydro-mechanical finite element model. The development of fault zone damage is simulated perpendicular to the main slip surface using a fully coupled solution of Navier's equation for mechanical deformation and Darcy's Law/conservation of fluid mass for subsurface fluid flow. The model is applied to study development of fault zones in basement rocks, based on the conceptual model of S. J. Martell, J. Struct. Geol. 12(7):869-882, 1990. We simulate the evolution of fault zones from pre-existing joints and explore controls on the growth rate and locations of multiple splay fractures which link-up to form complex damage zones. We are the first researchers to successfully simulate the temporal and spatial evolution of multiple wing cracks, tertiary fracturing, antithetic fractures propagating into the compressive region, infill fracturing between faults and

  17. Direct immunofluorescence testing in the diagnosis of immunobullous disease, collagen vascular disease, and vascular injury syndromes.

    Science.gov (United States)

    Magro, Cynthia M; Roberts-Barnes, Jennifer; Crowson, A Neil

    2012-10-01

    Direct and indirect immunofluorescence (IF) plays a role in the evaluation of immunobullous diseases and their mimics, and in the investigation of vascular injury syndromes and autoimmune connective tissue disease (CTD). IF mapping may be an important adjunct in the assessment of congenital epidermolysis bullosa syndromes and in Alport disease, in which antibodies are directed at certain components of the basement membrane zone to assay for their deficiency. In many cases of immunobullous and autoimmune CTDs, correlation with direct IF results is useful and often decisive in lesional evaluation and thus in patient management. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Nitrated type III collagen as a biological marker of nitric oxide-mediated synovial tissue metabolism in osteoarthritis

    DEFF Research Database (Denmark)

    Richardot, P; Charni-Ben Tabassi, N; Toh, L

    2009-01-01

    OBJECTIVES: Nitric oxide (NO) is a major mediator of joint tissue inflammation and damage in osteoarthritis (OA) and mediates the nitration of tyrosine (Y*) residues in proteins. We investigated the nitration of type III collagen, a major constituent of synovial membrane, in knee OA. METHODS: A p...... investigation of oxidative-related alterations of synovial tissue metabolism in OA....

  19. Transplantation of amniotic membrane to the subretinal space in pigs

    DEFF Research Database (Denmark)

    Kiilgaard, Jens Folke; Scherfig, Erik; Prause, Jan Ulrik

    2012-01-01

    Purpose. To investigate the effect of transplanted amniotic membrane (AM) on subretinal wound healing. Methods. Nine Danish Landrace pigs had surgical removal of retinal pigment epithelium (RPE) and mechanical damage of Bruch's membrane (BM) and served as a control group. 15 pigs additionally had...... is well tolerated in the subretinal space, causes only limited inflammation, and is covered with a monolayer of pigmented cells when in contact with the host RPE. Conclusions. AM modifies choroidal neovascularisation after BM damage and may serve as a basement membrane substitute for the RPE....

  20. Asporin competes with decorin for collagen binding, binds calcium and promotes osteoblast collagen mineralization

    DEFF Research Database (Denmark)

    Kalamajski, Sebastian; Aspberg, Anders; Lindblom, Karin

    2009-01-01

    The interactions of the ECM (extracellular matrix) protein asporin with ECM components have previously not been investigated. Here, we show that asporin binds collagen type I. This binding is inhibited by recombinant asporin fragment LRR (leucine-rich repeat) 10-12 and by full-length decorin......, but not by biglycan. We demonstrate that the polyaspartate domain binds calcium and regulates hydroxyapatite formation in vitro. In the presence of asporin, the number of collagen nodules, and mRNA of osteoblastic markers Osterix and Runx2, were increased. Moreover, decorin or the collagen-binding asporin fragment...... LRR 10-12 inhibited the pro-osteoblastic activity of full-length asporin. Our results suggest that asporin and decorin compete for binding to collagen and that the polyaspartate in asporin directly regulates collagen mineralization. Therefore asporin has a role in osteoblast-driven collagen...

  1. Daily consumption of the collagen supplement Pure Gold Collagen® reduces visible signs of aging

    Directory of Open Access Journals (Sweden)

    Borum

    2014-10-01

    Full Text Available Maryam Borumand, Sara Sibilla Minerva Research Labs Ltd., London, UK Abstract: With age, changes in the metabolic processes of structural components of the skin lead to visible signs of aging, such as increased dryness and wrinkle formation. The nutritional supplement, Pure Gold Collagen®, which consists of hydrolyzed collagen, hyaluronic acid, vitamins, and minerals, was developed to counteract these signs. An open-label study was conducted to investigate the effects of this nutritional supplement on skin properties. Supplementation with 50 mL of Pure Gold Collagen on a daily basis for 60 days led to a noticeable reduction in skin dryness, wrinkles, and nasolabial fold depth. In addition, a significant increase in collagen density and skin firmness was observed after 12 weeks. The data from this study suggest that Pure Gold Collagen can counteract signs of natural aging. Keywords: hydrolyzed collagen, antiaging, wrinkles, firmness, skin

  2. Efficacy of supraspinatus tendon repair using mesenchymal stem cells along with a collagen I scaffold

    OpenAIRE

    Tornero-Esteban, Pilar; Hoyas, Jos? Antonio; Villafuertes, Esther; Rodr?guez-Bobada, Cruz; L?pez-Gordillo, Yamila; Rojo, Francisco J.; Guinea, Gustavo V.; Paleczny, Anna; L?piz-Morales, Yaiza; Rodriguez-Rodriguez, Luis; Marco, Fernando; Fern?ndez-Guti?rrez, Benjam?n

    2015-01-01

    Objectives: Our main objective was to biologically improve rotator cuff healing in an elderly rat model using mesenchymal stem cells (MSCs) in combination with a collagen membrane and compared against other current techniques. Methods: A chronic rotator cuff tear injury model was developed by unilaterally detaching the supraspinatus (SP) tendons of Sprague-Dawley rats. At 1 month postinjury, the tears were repaired using one of the following techniques: (a) classical surgery using sutures...

  3. Umbilical Cord Mesenchymal Stem Cells Combined With a Collagenfibrin Double-layered Membrane Accelerates Wound Healing.

    Science.gov (United States)

    Nan, Wenbin; Liu, Rui; Chen, Hongli; Xu, Zhihao; Chen, Jiannan; Wang, Manman; Yuan, Zhiqing

    2015-05-01

    The aim of this study was to examine the effects of human umbilical cord mesenchymal stem cells (hUCMSCs) in combination with a collagen-fibrin double-layered membrane on wound healing in mice. A collagen-fibrin double-layered membrane was prepared, and the surface properties of the support material were investigated using a scanning electron microscope. Twenty-four mice were prepared for use as full-thickness skin wound models and randomly divided into 3 groups: group A, a control group in which the wounds were bound using a conventional method; group B, a group treated with hUCMSCs combined with a collagen membrane; and group C, a group treated with hUCMSCs combined with a collagen-fibrin double-layered membrane. The postoperative concrescence of the wounds was observed daily to evaluate the effects of the different treatments. Scanning electron microscope observation showed the collagen-fibrin scaffolds exhibited a highly porous and interconnected structure, and wound healing in the double-layered membrane group was better than in groups A or B. Treatment with hUCMSCs combined with a collagen-fibrin double-layered membrane accelerated wound healing.

  4. Collagen based Biomaterials from CLRI: An Inspiration from the ...

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Collagen based Biomaterials from CLRI: An Inspiration from the master. In 1950's, Collagen attracted Prof GN Ramachandran. He had a neighbor (CLRI) for whom collagen formed the substrate. He sought a sample of pure collagen from CLRI. This was provided.

  5. Chitosan: collagen sponges. In vitro mineralization

    International Nuclear Information System (INIS)

    Martins, Virginia da C.A.; Silva, Gustavo M.; Plepis, Ana Maria G.

    2011-01-01

    The regeneration of bone tissue is a problem that affects many people and scaffolds for bone tissue growth has been widely studied. The aim of this study was the in vitro mineralization of chitosan, chitosan:native collagen and chitosan:anionic collagen sponges. The sponges were obtained by lyophilization and mineralization was made by soaking the sponges in alternating solutions containing Ca 2+ and PO 4 3- . The mineralization was confirmed by infrared spectroscopy, energy dispersive X-ray and X-ray diffraction observing the formation of phosphate salts, possibly a carbonated hydroxyapatite since Ca/P=1.80. The degree of mineralization was obtained by thermogravimetry calculating the amount of residue at 750 deg C. The chitosan:anionic collagen sponge showed the highest degree of mineralization probably due to the fact that anionic collagen provides additional sites for interaction with the inorganic phase. (author)

  6. The minor collagens in articular cartilage

    DEFF Research Database (Denmark)

    Luo, Yunyun; Sinkeviciute, Dovile; He, Yi

    2017-01-01

    , especially minor collagens, including type IV, VI, IX, X, XI, XII, XIII, and XIV, etc. Although accounting for only a small fraction of the mature matrix, these minor collagens not only play essential structural roles in the mechanical properties, organization, and shape of articular cartilage, but also...... these minor collagens. The generation and release of fragmented molecules could generate novel biochemical markers with the capacity to monitor disease progression, facilitate drug development and add to the existing toolbox for in vitro studies, preclinical research and clinical trials....... fulfil specific biological functions. Genetic studies of these minor collagens have revealed that they are associated with multiple connective tissue diseases, especially degenerative joint disease. The progressive destruction of cartilage involves the degradation of matrix constituents including...

  7. Properties of Chitosan-Laminated Collagen Film

    Directory of Open Access Journals (Sweden)

    Vera Lazić

    2012-01-01

    Full Text Available The objective of this study is to determine physical, mechanical and barrier properties of chitosan-laminated collagen film. Commercial collagen film, which is used for making collagen casings for dry fermented sausage production, was laminated with chitosan film layer in order to improve the collagen film barrier properties. Different volumes of oregano essential oil per 100 mL of filmogenic solution were added to chitosan film layer: 0, 0.2, 0.4, 0.6 and 0.8 mL to optimize water vapour barrier properties. Chitosan layer with 0.6 or 0.8 % of oregano essential oil lowered the water vapour transmission rate to (1.85±0.10·10–6 and (1.78±0.03·10–6 g/(m2·s·Pa respectively, compared to collagen film ((2.51±0.05·10–6 g/(m2·s·Pa. However, chitosan-laminated collagen film did not show improved mechanical properties compared to the collagen one. Tensile strength decreased from (54.0±3.8 MPa of the uncoated collagen film to (36.3±4.0 MPa when the film was laminated with 0.8 % oregano essential oil chitosan layer. Elongation at break values of laminated films did not differ from those of collagen film ((18.4±2.7 %. Oxygen barrier properties were considerably improved by lamination. Oxygen permeability of collagen film was (1806.8±628.0·10–14 cm3/(m·s·Pa and values of laminated films were below 35·10–14 cm3/(m·s·Pa. Regarding film appearance and colour, lamination with chitosan reduced lightness (L and yellowness (+b of collagen film, while film redness (+a increased. These changes were not visible to the naked eye.

  8. Collagen Accumulation in Osteosarcoma Cells lacking GLT25D1 Collagen Galactosyltransferase*

    Science.gov (United States)

    Baumann, Stephan

    2016-01-01

    Collagen is post-translationally modified by prolyl and lysyl hydroxylation and subsequently by glycosylation of hydroxylysine. Despite the widespread occurrence of the glycan structure Glc(α1–2)Gal linked to hydroxylysine in animals, the functional significance of collagen glycosylation remains elusive. To address the role of glycosylation in collagen expression, folding, and secretion, we used the CRISPR/Cas9 system to inactivate the collagen galactosyltransferase GLT25D1 and GLT25D2 genes in osteosarcoma cells. Loss of GLT25D1 led to increased expression and intracellular accumulation of collagen type I, whereas loss of GLT25D2 had no effect on collagen secretion. Inactivation of the GLT25D1 gene resulted in a compensatory induction of GLT25D2 expression. Loss of GLT25D1 decreased collagen glycosylation by up to 60% but did not alter collagen folding and thermal stability. Whereas cells harboring individually inactivated GLT25D1 and GLT25D2 genes could be recovered and maintained in culture, cell clones with simultaneously inactive GLT25D1 and GLT25D2 genes could be not grown and studied, suggesting that a complete loss of collagen glycosylation impairs osteosarcoma cell proliferation and viability. PMID:27402836

  9. CREATION OF COLLAGEN PRODUCTS FISH RAW MATERIAL

    Directory of Open Access Journals (Sweden)

    L. V. Antipova

    2015-01-01

    Full Text Available Purposeful use of proteins of connecting fabrics is based first of all on structural and mechanical and physical and chemical properties of collagen, his physiology to a human body. Traditional source of collagen is the split of skins of the cattle, but in view of the objective reasons (spongy encephalopathy, reduction of a livestock of cattle, there was a need for search of alternative sources. The particular interest and popularity represent collagenic proteins in biomedical technologies, when receiving surgical sutural materials, wound healing means, prolongator of medicines, artificial organs and fabrics, implatant. New data on use the collagen containing of sources are directly connected with expansion of a source of raw materials of processing industries of agrarian and industrial complex on the basis of deep processing of biological resources and their maximum involvement in the main and special production with significant growth in an exit of useful products from raw materials unit. In this regard, researches of a microstructure of skins and fractional composition of proteins of objects of research are conducted; data on the general chemical composition and the content of collagen in them are received. Experimental data showed that the most perspective source of collagen from the studied fishes of internal reservoirs is the skin of a silver carp that is caused by the high content of target substance collagen, the low content of fat. The technology of receiving collagenic substances with the high technical characteristics allowing to apply them in production of medical materials is proved and realized in vitro. The comparative analysis showed that substances from a split of skins of cattle and a silver carp have an identical set of amino acids, but are characterized by the different content of separate amino acid s.

  10. Oriented collagen fibers direct tumor cell intravasation

    KAUST Repository

    Han, Weijing

    2016-09-24

    In this work, we constructed a Collagen I-Matrigel composite extracellular matrix (ECM). The composite ECM was used to determine the influence of the local collagen fiber orientation on the collective intravasation ability of tumor cells. We found that the local fiber alignment enhanced cell-ECM interactions. Specifically, metastatic MDA-MB-231 breast cancer cells followed the local fiber alignment direction during the intravasation into rigid Matrigel (∼10 mg/mL protein concentration).

  11. Unusual Fragmentation Pathways in Collagen Glycopeptides

    Science.gov (United States)

    Perdivara, Irina; Perera, Lalith; Sricholpech, Marnisa; Terajima, Masahiko; Pleshko, Nancy; Yamauchi, Mitsuo; Tomer, Kenneth B.

    2013-07-01

    Collagens are the most abundant glycoproteins in the body. One characteristic of this protein family is that the amino acid sequence consists of repeats of three amino acids -(X—Y—Gly)n. Within this motif, the Y residue is often 4-hydroxyproline (HyP) or 5-hydroxylysine (HyK). Glycosylation in collagen occurs at the 5-OH group in HyK in the form of two glycosides, galactosylhydroxylysine (Gal-HyK) and glucosyl galactosylhydroxylysine (GlcGal-HyK). In collision induced dissociation (CID), collagen tryptic glycopeptides exhibit unexpected gas-phase dissociation behavior compared to typical N- and O-linked glycopeptides (i.e., in addition to glycosidic bond cleavages, extensive cleavages of the amide bonds are observed). The Gal- or GlcGal- glycan modifications are largely retained on the fragment ions. These features enable unambiguous determination of the amino acid sequence of collagen glycopeptides and the location of the glycosylation site. This dissociation pattern was consistent for all analyzed collagen glycopeptides, regardless of their length or amino acid composition, collagen type or tissue. The two fragmentation pathways—amide bond and glycosidic bond cleavage—are highly competitive in collagen tryptic glycopeptides. The number of ionizing protons relative to the number of basic sites (i.e., Arg, Lys, HyK, and N-terminus) is a major driving force of the fragmentation. We present here our experimental results and employ quantum mechanics calculations to understand the factors enhancing the labile character of the amide bonds and the stability of hydroxylysine glycosides in gas phase dissociation of collagen glycopeptides.

  12. Collagen Fibrils: Nature's Highly Tunable Nonlinear Springs.

    Science.gov (United States)

    Andriotis, Orestis G; Desissaire, Sylvia; Thurner, Philipp J

    2018-03-21

    Tissue hydration is well known to influence tissue mechanics and can be tuned via osmotic pressure. Collagen fibrils are nature's nanoscale building blocks to achieve biomechanical function in a broad range of biological tissues and across many species. Intrafibrillar covalent cross-links have long been thought to play a pivotal role in collagen fibril elasticity, but predominantly at large, far from physiological, strains. Performing nanotensile experiments of collagen fibrils at varying hydration levels by adjusting osmotic pressure in situ during atomic force microscopy experiments, we show the power the intrafibrillar noncovalent interactions have for defining collagen fibril tensile elasticity at low fibril strains. Nanomechanical tensile tests reveal that osmotic pressure increases collagen fibril stiffness up to 24-fold in transverse (nanoindentation) and up to 6-fold in the longitudinal direction (tension), compared to physiological saline in a reversible fashion. We attribute the stiffening to the density and strength of weak intermolecular forces tuned by hydration and hence collagen packing density. This reversible mechanism may be employed by cells to alter their mechanical microenvironment in a reversible manner. The mechanism could also be translated to tissue engineering approaches for customizing scaffold mechanics in spatially resolved fashion, and it may help explain local mechanical changes during development of diseases and inflammation.

  13. Membranous nephropathy

    Science.gov (United States)

    ... check for hepatitis B, hepatitis C, and syphilis Complement levels Cryoglobulin test Treatment The goal of treatment ... not as helpful for people with membranous nephropathy. Medicines used treat membranous nephropathy include: Angiotensin-converting enzyme ( ...

  14. Fault assessment for basement reservoir compartmentalization: Case study at Northeast Betara gas field, South Sumatra Basin

    Science.gov (United States)

    Risyad, M.; Suta, I. N.; Haris, A.

    2017-07-01

    Northeast Betara field is situated on the northern part of prolific South Sumatra Basin. It has produced gas from Lower Talang Akar Formation sandstone and over 90 wells have been drilled. A 3D seismic data was acquired in 2000 and reprocessed in 2012 to enhance the subsurface image. In 2013 an exploratory well NEB Base-1 was drilled and made gas and condensate discovery from the subsequent pre-tertiary basement which is confirmed as granite. The well proved fractured basement reservoir play on paleo high of the structure. The absence of full-diameter conventional core prompts well logs and seismic data analysis by using a workstation. Main methods for fracture prediction have been seismic attributes extraction and structural geology studies of basement provided by image logs on a few exploration wells. Ant tracking attribute is widely employed to image seismic event discontinuities due to extensive faults which generated the natural fractures. Delineations well NEB Base-2 was drilled on second paleo high and unfortunately, it did not find any gas indication from pre-tertiary basement target. Seismic structural interpretation and seismic attributes are conducted to image distribution of event discontinuities related to faults or fracture. We found that compartmentalization on basement involved old faults and both paleo high have undergone different structural history and stress character which resulted in separated fractures distribution.

  15. BASECALC - software for residential basement and slab-on-grade heat-loss analysis

    Energy Technology Data Exchange (ETDEWEB)

    Beausoleil-Morrison, I. [Natural Resources Canada, Ottawa, ON (Canada). Office of Energy Efficiency

    1999-11-01

    BASECALC models heat losses from residential building basements and slabs-on-grade by calculating heat loss based on thermal and physical properties of individual construction, insulation type and location, ground properties and weather. BASECALC provides bilingual software and numerical, graphical and parametric output. It can model above-grade and below-grade heat losses and include the effects of thermal bridging between the basement and the main-floor envelope. This is then validated against the National Research Council of Canada`s Mitalas method. The software can calculate insulation configurations with code implications and carry out batch processing for multiple runs. It includes libraries of common insulation and construction materials. BASECALC has the potential in other applications to develop more accurate basement algorithms for building simulation programs, establish building and energy code requirements for basement and slab-on-grade insulation, assess and demonstrate the performance of new products and novel insulation placements, and validate and calibrate basement heat-loss predictions from building simulation programs.

  16. The metamorphic basement of the Cordillera Frontal of Mendoza: New geochronologic and isotopic data

    International Nuclear Information System (INIS)

    Basei, Miguel; Ramos, Victor A.; Vujovich, Graciela I.; Poma, Stella

    1998-01-01

    The metamorphic rocks of the Cordillera Frontal exposed in the Cordon del Portillo, Mendoza were examined by Rb/Sr geochronology and Nd/Sm isotopic analysis. The Rb/Sr data defined a Devonian age for the last metamorphic episode, similar to the previous K/Ar and Ar/Ar ages obtained in this region and western Precordillera. The isotopic analysis identified three sets of model ages: 1.- The oldest corresponds to a set of meta sedimentary rocks with a model age of 1,400 to 1,700 Ma; 2.- A monzogranodiorite with a model age of 1,000 Ma; and 3.- Metabasites with model ages between 577 and 330 Ma. These rocks are interpreted as 1.- A typical Grenvillian derived basement; 2.- Late Paleozoic granitoids derived from a different Proterozoic basement; and 3.- Some Eopaleozoic metabasites tectonically inter fingered with the Grenvillian basement. These new data are coherent with the existence of a Laurentia derived terrane, Chilenia, that was separated by oceanic rocks from the basement of Pre cordillera during Eopaleozoic times. This last basement known as the Cuyania terrane, was also derived from Laurentia. (author)

  17. Structure of corneal layers, collagen fibrils, and proteoglycans of tree shrew cornea.

    Science.gov (United States)

    Almubrad, Turki; Akhtar, Saeed

    2011-01-01

    The stroma is the major part of the cornea, in which collagen fibrils and proteoglycans are distributed uniformly. We describe the ultrastructure of corneal layers, collagen fibrils (CF), and proteoglycans (PGs) in the tree shrew cornea. Tree shrew corneas (5, 6, and 10 week old animals) and normal human corneas (24, 25, and 54 years old) were fixed in 2.5% glutaraldehyde containing cuprolinic blue in a sodium acetate buffer. The tissue was processed for electron microscopy. The 'iTEM Olympus Soft Imaging Solutions GmbH' program was used to measure the corneal layers, collagen fibril diameters and proteoglycan areas. The tree shrew cornea consists of 5 layers: the epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium. The epithelium was composed of squamous cells, wing cells and basal cells. The Bowman's layer was 5.5±1.0 µm thick and very similar to a normal human Bowman's layer. The stroma was 258±7.00 µm thick and consisted of collagen fibril lamellae. The lamellae were interlaced with one another in the anterior stroma, but ran parallel to one another in the middle and posterior stroma. Collagen fibrils were decorated with proteoglycan filaments with an area size of 390 ±438 nm(2). The collagen fibril had a minimum diameter of 39±4.25 nm. The interfibrillar spacing was 52.91±6.07 nm. Within the collagen fibrils, very small electron-dense particles were present. The structure of the tree shrew cornea is very similar to that of the normal human cornea. As is the case with the human cornea, the tree shrew cornea had a Bowman's layer, lamellar interlacing in the anterior stroma and electron-dense particles within the collagen fibrils. The similarities of the tree shrew cornea with the human cornea suggest that it could be a good structural model to use when studying changes in collagen fibrils and proteoglycans in non-genetic corneal diseases, such as ectasia caused after LASIK (laser-assisted in situ keratomileusis).

  18. Structure of corneal layers, collagen fibrils, and proteoglycans of tree shrew cornea

    Science.gov (United States)

    Almubrad, Turki

    2011-01-01

    Purpose The stroma is the major part of the cornea, in which collagen fibrils and proteoglycans are distributed uniformly. We describe the ultrastructure of corneal layers, collagen fibrils (CF), and proteoglycans (PGs) in the tree shrew cornea. Methods Tree shrew corneas (5, 6, and 10 week old animals) and normal human corneas (24, 25, and 54 years old) were fixed in 2.5% glutaraldehyde containing cuprolinic blue in a sodium acetate buffer. The tissue was processed for electron microscopy. The ‘iTEM Olympus Soft Imaging Solutions GmbH’ program was used to measure the corneal layers, collagen fibril diameters and proteoglycan areas. Results The tree shrew cornea consists of 5 layers: the epithelium, Bowman’s layer, stroma, Descemet’s membrane, and endothelium. The epithelium was composed of squamous cells, wing cells and basal cells. The Bowman’s layer was 5.5±1.0 µm thick and very similar to a normal human Bowman’s layer. The stroma was 258±7.00 µm thick and consisted of collagen fibril lamellae. The lamellae were interlaced with one another in the anterior stroma, but ran parallel to one another in the middle and posterior stroma. Collagen fibrils were decorated with proteoglycan filaments with an area size of 390 ±438 nm2. The collagen fibril had a minimum diameter of 39±4.25 nm. The interfibrillar spacing was 52.91±6.07 nm. Within the collagen fibrils, very small electron-dense particles were present. Conclusions The structure of the tree shrew cornea is very similar to that of the normal human cornea. As is the case with the human cornea, the tree shrew cornea had a Bowman's layer, lamellar interlacing in the anterior stroma and electron-dense particles within the collagen fibrils. The similarities of the tree shrew cornea with the human cornea suggest that it could be a good structural model to use when studying changes in collagen fibrils and proteoglycans in non-genetic corneal diseases, such as ectasia caused after LASIK (laser

  19. Characteristic aerial and ground radioactives of basement and sedimentary rocks in (Egypt): relations and natural cycles across geologic time

    International Nuclear Information System (INIS)

    Ammar, A.A.

    1998-01-01

    Each geologic unit, exposure, formation or rock group of the exposed precambrian I (igneous and metamorphic) basement complex (Upper proterozoic) and phanerozoic cover sediments in an area covering about 4500 km2 located in the central eastern desert of egypt, has been found to possess certain radioactivity characteristics and levels. Minimum values of radiation are generally associated with the first basement volcanics, maximum values are correlated are correlated with the third basement plutonites and phosphate formation (upper cretaceous), while intermedialte values are connected with the first basement sediments and upper eocene-quaternary fifth detrital-calcareous-evaporite sediments. Therefore, the radioactivities of various rock groups of the precambrian I basement complex - except the first basement sediments sediments- correlate progressively well with their chronology. Generally, the increase of radioactivity within this complex is connected with the transition into final stages of the magmatic evolution

  20. Dissolution of biogenic ooze over basement edifices in the equatorial Pacific with implications for hydrothermal ventilation of the oceanic crust

    Science.gov (United States)

    Bekins, B.A.; Spivack, A.J.; Davis, E.E.; Mayer, L.A.

    2007-01-01

    Recent observations indicate that curious closed depressions in carbonate sediments overlying basement edifices are widespread in the equatorial Pacific. A possible mechanism for their creation is dissolution by fluids exiting basement vents from off-axis hydrothermal flow. Quantitative analysis based on the retrograde solubility of calcium carbonate and cooling of basement fluids during ascent provides an estimate for the dissolution capacity of the venting fluids. Comparison of the dissolution capacity and fluid flux with typical equatorial Pacific carbonate mass accumulation rates shows that this mechanism is feasible. By maintaining sediment-free basement outcrops, the process may promote widespread circulation of relatively unaltered seawater in the basement in an area where average sediment thicknesses are 300-500 m. The enhanced ventilation can explain several previously puzzling observations in this region, including anomalously low heat flux, relatively unaltered seawater in the basement, and aerobic and nitrate-reducing microbial activity at the base of the sediments. ?? 2007 The Geological Society of America.

  1. RESEARCH ON REDUCING PREMATURITY RUPTURE OF MEMBRANE

    Directory of Open Access Journals (Sweden)

    Maria URSACHI (BOLOTA

    2016-12-01

    Full Text Available The membranes surrounding the amniotic cavity are composed from amnion and chorion, tightly adherent layers which are composed of several cell types, including epithelial cells, trophoblasts cells and mesenchyme cells, embedded in a collagenous matrix. They retain amniotic fluid, secret substances into the amniotic fluid, as well as to the uterus and protect the fetus against upward infections from urogenital tract. Normally, the membranes it breaks during labor. Premature rupture of the amniotic sac (PRAS is defined as rupture of membranes before the onset of labor. Premature rupture of the fetal membrane, which occurs before 37 weeks of gestation, usually, refers to preterm premature rupture of membranes. Despite advances in the care period, premature rupture of membranes and premature rupture of membranes preterm continue to be regarded as serious obstetric complications. On the term 8% - 10% of pregnant women have premature rupture of membranes; these women are at increased risk of intrauterine infections, where the interval between membrane rupture and expulsion is rolled-over. Premature rupture of membranes preterm occurs in approximately 1% of all pregnancies and is associated with 30% -40% of preterm births. Thus, it is important to identify the cause of pre-term birth (after less than 37 completed weeks of "gestation" and its complications, including respiratory distress syndrome, neonatal infection and intraventricular hemorrhage. Objectives: the development of the protocol of the clinical trial on patients with impending preterm birth, study clinical and statistical on the socio-demographic characteristics of patients with imminent preterm birth; clinical condition of patients and selection of cases that could benefit from the application of interventional therapy; preclinical investigation (biological and imaging of patients with imminent preterm birth; the modality therapy; clinical investigation of the effectiveness of short

  2. The preosteoblast response of electrospinning PLGA/PCL nanofibers: effects of biomimetic architecture and collagen I

    Directory of Open Access Journals (Sweden)

    Qian YZ

    2016-08-01

    Full Text Available Yunzhu Qian,1,2 Hanbang Chen,1 Yang Xu,1 Jianxin Yang,2 Xuefeng Zhou,3 Feimin Zhang,1 Ning Gu3 1Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, 2Center of Stomatology, The Second Affiliated Hospital of Soochow University, Suzhou, 3School of Biological Science and Medical Engineering, Southeast University, Nanjing, People’s Republic of China Abstract: Constructing biomimetic structure and incorporating bioactive molecules is an effective strategy to achieve a more favorable cell response. To explore the effect of electrospinning (ES nanofibrous architecture and collagen I (COL I-incorporated modification on tuning osteoblast response, a resorbable membrane composed of poly(lactic-co-glycolic acid/poly(caprolactone (PLGA/PCL; 7:3 w/w was developed via ES. COL I was blended into PLGA/PCL solution to prepare composite ES membrane. Notably, relatively better cell response was delivered by the bioactive ES-based membrane which was fabricated by modification of 3,4-dihydroxyphenylalanine and COL I. After investigation by field emission scanning electron microscopy, Fourier transform infrared spectroscopy, contact angle measurement, and mechanical test, polyporous three-dimensional nanofibrous structure with low tensile force and the successful integration of COL I was obtained by the ES method. Compared with traditional PLGA/PCL membrane, the surface hydrophilicity of collagen-incorporated membranes was largely enhanced. The behavior of mouse preosteoblast MC3T3-E1 cell infiltration and proliferation on membranes was studied at 24 and 48 hours. The negative control was fabricated by solvent casting. Evaluation of cell adhesion and morphology demonstrated that all the ES membranes were more favorable for promoting the cell adhesion and spreading than the casting membrane. Cell Counting Kit-8 assays revealed that biomimetic architecture, surface topography, and bioactive properties of membranes were favorable for cell

  3. Inversion of gravity data in the Big Bear Lake Area to recover depth to basement using Cauchy-type integrals

    DEFF Research Database (Denmark)

    Cai, Hongzhu; Zhdanov, Michael

    2014-01-01

    One of the important applications of the gravity method is evaluation of the depth to the basement, which is characterized by a significant density contrast with the sedimental layeres. We have introduced recently a new method of modeling and inversion of potential field data generated by a density...... response caused by sediment-basement interface with variable density in depth. We have also developed the inversion of gravity data to recover the depth to basement given the density profile with depth....

  4. Membrane Biophysics

    CERN Document Server

    Ashrafuzzaman, Mohammad

    2013-01-01

    Physics, mathematics and chemistry all play a vital role in understanding the true nature and functioning of biological membranes, key elements of living processes. Besides simple spectroscopic observations and electrical measurements of membranes we address in this book the phenomena of coexistence and independent existence of different membrane components using various theoretical approaches. This treatment will be helpful for readers who want to understand biological processes by applying both simple observations and fundamental scientific analysis. It provides a deep understanding of the causes and effects of processes inside membranes, and will thus eventually open new doors for high-level pharmaceutical approaches towards fighting membrane- and cell-related diseases.

  5. Effects of 3D-Printed Polycaprolactone/β-Tricalcium Phosphate Membranes on Guided Bone Regeneration

    OpenAIRE

    Jin-Hyung Shim; Joo-Yun Won; Jung-Hyung Park; Ji-Hyeon Bae; Geunseon Ahn; Chang-Hwan Kim; Dong-Hyuk Lim; Dong-Woo Cho; Won-Soo Yun; Eun-Bin Bae; Chang-Mo Jeong; Jung-Bo Huh

    2017-01-01

    This study was conducted to compare 3D-printed polycaprolactone (PCL) and polycaprolactone/?-tricalcium phosphate (PCL/?-TCP) membranes with a conventional commercial collagen membrane in terms of their abilities to facilitate guided bone regeneration (GBR). Fabricated membranes were tested for dry and wet mechanical properties. Fibroblasts and preosteoblasts were seeded into the membranes and rates and patterns of proliferation were analyzed using a kit-8 assay and by scanning electron micro...

  6. Thrombin induces epithelial-mesenchymal transition and collagen production by retinal pigment epithelial cells via autocrine PDGF-receptor signaling.

    Science.gov (United States)

    Bastiaans, Jeroen; van Meurs, Jan C; van Holten-Neelen, Conny; Nagtzaam, Nicole M A; van Hagen, P Martin; Chambers, Rachel C; Hooijkaas, Herbert; Dik, Willem A

    2013-12-19

    De-differentiation of RPE cells into mesenchymal cells (epithelial-mesenchymal transition; EMT) and associated collagen production contributes to development of proliferative vitreoretinopathy (PVR). In patients with PVR, intraocular coagulation cascade activation occurs and may play an important initiating role. Therefore, we examined the effect of the coagulation proteins factor Xa and thrombin on EMT and collagen production by RPE cells. Retinal pigment epithelial cells were stimulated with factor Xa or thrombin and the effect on zonula occludens (ZO)-1, α-smooth muscle actin (α-SMA), collagen, and platelet-derived growth factor (PDGF)-B were determined by real-time quantitative-polymerase chain reaction (RQ-PCR), immunofluorescence microscopy, and HPLC and ELISA for collagen and PDGF-BB in culture supernatants, respectively. PDGF-receptor activation was determined by phosphorylation analysis and inhibition studies using the PDGF-receptor tyrosine kinase inhibitor AG1296. Thrombin reduced ZO-1 gene expression (P production of α-SMA and collagen increased. In contrast to thrombin, factor Xa hardly stimulated EMT by RPE. Thrombin clearly induced PDGF-BB production and PDGF-Rβ chain phosphorylation in RPE. Moreover, AG1296 significantly blocked the effect of thrombin on EMT and collagen production. Our findings demonstrate that thrombin is a potent inducer of EMT by RPE via autocrine activation of PDGF-receptor signaling. Coagulation cascade-induced EMT of RPE may thus contribute to the formation of fibrotic retinal membranes in PVR and should be considered as treatment target in PVR.

  7. Adherence, proliferation and collagen turnover by human fibroblasts seeded into different types of collagen sponges

    NARCIS (Netherlands)

    Middelkoop, E.; de Vries, H. J.; Ruuls, L.; Everts, V.; Wildevuur, C. H.; Westerhof, W.

    1995-01-01

    We describe an in vitro model that we have used to evaluate dermal substitutes and to obtain data on cell proliferation, the rate of degradation of the dermal equivalent, contractibility and de novo synthesis of collagen. We tested three classes of collagenous materials: (1) reconstituted

  8. ADHERENCE, PROLIFERATION AND COLLAGEN TURNOVER BY HUMAN FIBROBLASTS SEEDED INTO DIFFERENT TYPES OF COLLAGEN SPONGES

    NARCIS (Netherlands)

    MIDDELKOOP, E; DEVRIES, HJC; RUULS, L; EVERTS, [No Value; WILDEVUUR, CHR; WESTERHOF, W

    We describe an in vitro model that we have used to evaluate dermal substitutes and to obtain data on cell proliferation, the rate of degradation of the dermal equivalent, contractibility and de novo synthesis of collagen. We tested three classes of collagenous materials: (1) reconstituted

  9. Collagen-binding peptidoglycans inhibit MMP mediated collagen degradation and reduce dermal scarring.

    Directory of Open Access Journals (Sweden)

    Kate Stuart

    Full Text Available Scarring of the skin is a large unmet clinical problem that is of high patient concern and impact. Wound healing is complex and involves numerous pathways that are highly orchestrated, leaving the skin sealed, but with abnormal organization and composition of tissue components, namely collagen and proteoglycans, that are then remodeled over time. To improve healing and reduce or eliminate scarring, more rapid restoration of healthy tissue composition and organization offers a unique approach for development of new therapeutics. A synthetic collagen-binding peptidoglycan has been developed that inhibits matrix metalloproteinase-1 and 13 (MMP-1 and MMP-13 mediated collagen degradation. We investigated the synthetic peptidoglycan in a rat incisional model in which a single dose was delivered in a hyaluronic acid (HA vehicle at the time of surgery prior to wound closure. The peptidoglycan treatment resulted in a significant reduction in scar tissue at 21 days as measured by histology and visual analysis. Improved collagen architecture of the treated wounds was demonstrated by increased tensile strength and transmission electron microscopy (TEM analysis of collagen fibril diameters compared to untreated and HA controls. The peptidoglycan's mechanism of action includes masking existing collagen and inhibiting MMP-mediated collagen degradation while modulating collagen organization. The peptidoglycan can be synthesized at low cost with unique design control, and together with demonstrated preclinical efficacy in reducing scarring, warrants further investigation for dermal wound healing.

  10. The osteoinductive effect of chitosan-collagen composites around pure titanium implant surfaces in rats.

    Science.gov (United States)

    Kung, S; Devlin, H; Fu, E; Ho, K-Y; Liang, S-Y; Hsieh, Y-D

    2011-02-01

    The enhancing effects of chitosan on activation of platelets and differentiation of osteoprogenitor cells have been demonstrated in vitro. The purpose of this study was to evaluate the in vivo osteoinductive effect of chitosan-collagen composites around pure titanium implant surfaces. Chitosan-collagen composites containing chitosan of different molecular weights (450 and 750 kDa) were wrapped onto titanium implants and embedded into the subcutaneous area on the back of 15 Sprague-Dawley rats. The control consisted of implants wrapped with plain collagen type I membranes. Implants and surrounding tissues were retrieved 6 wks after surgery and identified by Alizarin red and Alcian blue whole mount staining. The newly formed structures in the test groups were further analyzed by Toluidine blue and Masson-Goldner trichrome staining, and immunohistochemical staining with osteopontin and alkaline phosphotase. The bone formation parameters of the new bone in the two test groups were measured and compared. New bone formed ectopically in both chitosan-collagen groups, whereas no bone induction occurred in the negative control group. These newly formed bone-like structures were further confirmed by immunohistochemical staining. Comparison of bone parameters of the newly induced bone revealed no statistically significant differences between the 450 and 750 kDa chitosan-collagen groups. Our results demonstrated that chitosan-collagen composites might induce in vivo new bone formation around pure titanium implant surfaces. Different molecular weights of chitosan did not show significantly different effects on the osteoinductive potential of the test materials. © 2010 John Wiley & Sons A/S.

  11. Modeling and process optimization of electrospinning of chitosan-collagen nanofiber by response surface methodology

    Science.gov (United States)

    Amiri, Nafise; Moradi, Ali; Abolghasem Sajjadi Tabasi, Sayyed; Movaffagh, Jebrail

    2018-04-01

    Chitosan-collagen composite nanofiber is of a great interest to researchers in biomedical fields. Since the electrospinning is the most popular method for nanofiber production, having a comprehensive knowledge of the electrospinning process is beneficial. Modeling techniques are precious tools for managing variables in the electrospinning process, prior to the more time- consuming and expensive experimental techniques. In this study, a central composite design of response surface methodology (RSM) was employed to develop a statistical model as well as to define the optimum condition for fabrication of chitosan-collagen nanofiber with minimum diameter. The individual and the interaction effects of applied voltage (10–25 kV), flow rate (0.5–1.5 mL h‑1), and needle to collector distance (15–25 cm) on the fiber diameter were investigated. ATR- FTIR and cell study were done to evaluate the optimized nanofibers. According to the RSM, a two-factor interaction (2FI) model was the most suitable model. The high regression coefficient value (R 2 ≥ 0.9666) of the fitted regression model and insignificant lack of fit (P = 0.0715) indicated that the model was highly adequate in predicting chitosan-collagen nanofiber diameter. The optimization process showed that the chitosan-collagen nanofiber diameter of 156.05 nm could be obtained in 9 kV, 0.2 ml h‑1, and 25 cm which was confirmed by experiment (155.92 ± 18.95 nm). The ATR-FTIR and cell study confirmed the structure and biocompatibility of the optimized membrane. The represented model could assist researchers in fabricating chitosan-collagen electrospun scaffolds with a predictable fiber diameter, and optimized chitosan-collagen nanofibrous mat could be a potential candidate for wound healing and tissue engineering.

  12. Fracture Analysis of basement rock: A case example of the Eastern Part of the Peninsular Malaysia

    International Nuclear Information System (INIS)

    Shamsuddin, A; Ghosh, D

    2015-01-01

    In general, reservoir rocks can be defined into carbonates, tight elastics and basement rocks. Basement rocks came to be highli