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Sample records for subepithelial collagen deposition

  1. Collagenous Gastritis

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    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.

  2. Quantification of collagen and proteoglycan deposition in a murine model of airway remodelling

    Science.gov (United States)

    Reinhardt, Alistair K; Bottoms, Stephen E; Laurent, Geoffrey J; McAnulty, Robin J

    2005-01-01

    Background Sub-epithelial extracellular matrix deposition is a feature of asthmatic airway remodelling associated with severity of disease, decline in lung function and airway hyperresponsiveness. The composition of, and mechanisms leading to, this increase in subepithelial matrix, and its importance in the pathogenesis of asthma are unclear. This is partly due to limitations of the current models and techniques to assess airway remodelling. Methods In this study we used a modified murine model of ovalbumin sensitisation and challenge to reproduce features of airway remodelling, including a sustained increase in sub-epithelial matrix deposition. In addition, we have established techniques to accurately and specifically measure changes in sub-epithelial matrix deposition, using histochemical and immunohistochemical staining in conjunction with digital image analysis, and applied these to the measurement of collagen and proteoglycans. Results 24 hours after final ovalbumin challenge, changes similar to those associated with acute asthma were observed, including inflammatory cell infiltration, epithelial cell shedding and goblet cell hyperplasia. Effects were restricted to the bronchial and peribronchial regions with parenchymal lung of ovalbumin sensitised and challenged mice appearing histologically normal. By 12 days, the acute inflammatory changes had largely resolved and increased sub-epithelial staining for collagen and proteoglycans was observed. Quantitative digital image analysis confirmed the increased deposition of sub-epithelial collagen (33%, p proteoglycans (32%, p proteoglycan deposition in an animal model of airway remodelling. This model will be useful for measurement of other matrix components, as well as for assessment of the molecular mechanisms contributing to, and agents to modulate airway remodelling. PMID:15819978

  3. Comparative evaluation of management of gingival recession using subepithelial connective tissue graft and collagen membrane by periodontal microsurgical technique: A clinical study of 40 cases.

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    Thankkappan, Prasanth; Roy, Subrata; Mandlik, Vivek Bapurao

    2016-01-01

    New technologies, instruments, and surgical techniques are necessary to help the clinician ensure the best result and satisfy the patient's expectations, and surgical microscope has been thoroughly demonstrated as a useful tool. A clinical study was carried out to compare 2 different types of root coverage procedures using periodontal microsurgical procedure. Forty patients were selected and divided into Group A and Group B. Group A subjects were treated with subepithelial connective tissue graft (CTG) whereas Group B subjects were treated using a resorbable collagen membrane. The procedures were performed with the help of an operating microscope using 250 mm objective lens and ×6 magnification. A comparison between baseline, 1, 3, and 12 months have been done between groups among all parameters. It has been noticed that the root coverage was better in Group A subjects at all time. At 12 months, Group A showed 81.42% coverage where in Group B it was 70.08%. Similarly, increase in the width of keratinized gingiva and attached gingiva were more in Group A. The present study showed that use of microsurgical instrument helped to deliver precise incision, better visual acuity, and improved illumination which facilitate to gain a better final outcome. Root coverage was better in the patients using CTG.

  4. Soft tissue volume alterations after connective tissue grafting at teeth: the subepithelial autologous connective tissue graft versus a porcine collagen matrix - a pre-clinical volumetric analysis.

    Science.gov (United States)

    Schmitt, Christian M; Matta, Ragai E; Moest, Tobias; Humann, Julia; Gammel, Lisa; Neukam, Friedrich W; Schlegel, Karl A

    2016-07-01

    This study evaluates a porcine collagen matrix (CM) for soft tissue thickening in comparison to the subepithelial connective tissue graft (SCTG). In eight beagle dogs, soft tissue thickening was performed at the buccal aspects of the upper canines (SCTG and CM). Impressions were taken before augmentation (i1), after surgery (i2), after one (i3), three (i4) and ten month (i5). Casts were optically scanned with a 3D scanner and each augmented region (unit of analysis) evaluated (primary outcome variable: volume increase in mm(3) ; secondary outcome variables: volume increase in percent, mean and maximum thickness increases in mm). 3D tissue measurements after surgery revealed a significant higher volume increase in the CM (86.37 mm(3)  ± 35.16 mm(3) ) than in the SCTG group (47.65 mm(3)  ± 17.90 mm(3) ). After 10 months, volume increase was non-significant between groups (SCTG:11.36 mm(3)  ± 9.26 mm(3) ; CM: 8.67 mm(3)  ± 13.67 mm(3) ). Maximum soft tissue thickness increase (i1-i5) was 0.66 mm ± 0.29 mm (SCTG) and 0.79 mm ± 0.37 mm (CM) with no significant difference. Ten months after soft tissue thickening, the CM is statistically non-inferior to the SCTG in terms of soft tissue volume and thickness increase. Further 3D studies are needed to confirm the data. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Electrochemical deposition of mineralized BSA/collagen coating

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Junjun [School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); Lin, Jun; Li, Juan; Wang, Huiming [The First Affiliated Hospital of Medical College, Zhejiang University, Hangzhou 310003 (China); Cheng, Kui [School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); Weng, Wenjian, E-mail: wengwj@zju.edu.cn [School of Materials Science and Engineering, State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027 (China); The Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)

    2016-09-01

    In this work, mineralized collagen coatings with different loading quantity of bovine serum albumin (BSA) were prepared via in situ electrochemical deposition on titanium substrate. The microstructure and BSA loading quantity of the coatings could be controlled by the electrochemical deposition parameters, such as deposition potential, BSA concentration and its adding sequence in the electrolyte. The BSA loading quantity in the coatings was obtained in the range of 0.0170–0.173 mg/cm{sup 2}, enhancing the cell adhesion and proliferation of the coatings with the simultaneous release. The distinct release behaviors of BSA were attributed to their gradient distribution with different mineralization degrees, which could be adjusted by the deposition process. These results suggest that in situ electrochemical deposition is a promising way to incorporate functional molecules into the mineralized collagen coatings and the mineralized BSA/collagen coatings are highly promising for improving the rhBMP-2 loading capability (1.8-fold). - Highlights: • BSA is incorporated into mineralized collagen coating by electrochemical deposition. • The loading amount of BSA in coatings can be adjusted in the range of 0-173 ng. • The BSA/collagen coating shows good cytocompatibility with free-albumin culture. • The incorporation process is put forward for some other molecules deposition.

  6. Intestinal intraepithelial lymphocyte cytometric pattern is more accurate than subepithelial deposits of anti-tissue transglutaminase IgA for the diagnosis of celiac disease in lymphocytic enteritis.

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    Fernando Fernández-Bañares

    Full Text Available BACKGROUND & AIMS: An increase in CD3+TCRγδ+ and a decrease in CD3- intraepithelial lymphocytes (IEL is a characteristic flow cytometric pattern of celiac disease (CD with atrophy. The aim was to evaluate the usefulness of both CD IEL cytometric pattern and anti-TG2 IgA subepithelial deposit analysis (CD IF pattern for diagnosing lymphocytic enteritis due to CD. METHODS: Two-hundred and five patients (144 females who underwent duodenal biopsy for clinical suspicion of CD and positive celiac genetics were prospectively included. Fifty had villous atrophy, 70 lymphocytic enteritis, and 85 normal histology. Eight patients with non-celiac atrophy and 15 with lymphocytic enteritis secondary to Helicobacter pylori acted as control group. Duodenal biopsies were obtained to assess both CD IEL flow cytometric (complete or incomplete and IF patterns. RESULTS: Sensitivity of IF, and complete and incomplete cytometric patterns for CD diagnosis in patients with positive serology (Marsh 1+3 was 92%, 85 and 97% respectively, but only the complete cytometric pattern had 100% specificity. Twelve seropositive and 8 seronegative Marsh 1 patients had a CD diagnosis at inclusion or after gluten free-diet, respectively. CD cytometric pattern showed a better diagnostic performance than both IF pattern and serology for CD diagnosis in lymphocytic enteritis at baseline (95% vs 60% vs 60%, p = 0.039. CONCLUSIONS: Analysis of the IEL flow cytometric pattern is a fast, accurate method for identifying CD in the initial diagnostic biopsy of patients presenting with lymphocytic enteritis, even in seronegative patients, and seems to be better than anti-TG2 intestinal deposits.

  7. Resolution of Paraneoplastic Collagenous Enterocolitis after Resection of Colon Cancer

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    Hugh J Freeman

    2006-01-01

    Full Text Available A 52-year-old woman developed severe watery diarrhea, weight loss, anemia and hypoalbuminemia. A localized colon cancer was detected. Subsequently, extensive collagenous mucosal involvement of the small and large intestine was discovered. After resection of the colon cancer, her symptoms resolved. In addition, resolution of the inflammatory process occurred, including the subepithelial collagen deposits. Despite extensive small and large intestinal involvement, both clinical and histological resolution of collagenous inflammatory disease was evident. Collagenous enterocolitis is an inflammatory process that may represent a distinctive and reversible paraneoplastic phenomenon.

  8. Tenascin-x deficiency mimics ehlers-danlos syndrome in mice through alteration of collagen deposition

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    Mao, J.R.; Taylor, G.; Dean, W.B.; Wagner, D.R.; Afzal, V.; Lotz, J.C.; Rubin, E.M.; Bristow, J.

    2002-03-01

    Tenascin-X is a large extracellular matrix protein of unknown function1-3. Tenascin-X deficiency in humans is associated with Ehlers-Danlos syndrome4,5, a generalized connective tissue disorder resulting from altered metabolism of the fibrillar collagens6. Because TNXB is the first Ehlers-Danlos syndrome gene that does not encode a fibrillar collagen or collagen-modifying enzyme7-14, we suggested that tenascin-X might regulate collagen synthesis or deposition15. To test this hypothesis, we inactivated Tnxb in mice. Tnxb-/- mice showed progressive skin hyperextensibility, similar to individuals with Ehlers-Danlos syndrome. Biomechanical testing confirmed increased deformability and reduced tensile strength of their skin. The skin of Tnxb-/- mice was histologically normal, but its collagen content was significantly reduced. At the ultrastructural level, collagen fibrils of Tnxb-/- mice were of normal size and shape, but the density of fibrils in their skin was reduced, commensurate with the reduction in collagen content. Studies of cultured dermal fibroblasts showed that although synthesis of collagen I by Tnxb-/- and wildtype cells was similar, Tnxb-/- fibroblasts failed to deposit collagen I into cell-associated matrix. This study confirms a causative role for TNXB in human Ehlers-Danlos syndrome and suggests that tenascin-X is an essential regulator of collagen deposition by dermal fibroblasts.

  9. Blood flow changes using a 3D xenogeneic collagen matrix or a subepithelial connective tissue graft for root coverage procedures: a pilot study.

    Science.gov (United States)

    Tatarakis, Nikolaos; Gkranias, Nikolaos; Darbar, Ulpee; Donos, Nikolaos

    2017-10-27

    The study investigated the early healing process following the treatment of single Miller class I and II recessions with a 3D xenogeneic collagen matrix (CMX) or connective tissue graft (CTG). This pilot investigation was designed as a single-center randomized controlled parallel trial. A total of eight subjects (four per group) were treated with either CMX or CTG in the anterior maxilla. Vascular flow changes were assessed by laser Doppler flowmetry (LDF) before and after surgery and at days 1, 2, 3, 7, 14, and 30 while clinical evaluations took place at baseline and at days 60 and 180. Pain intensity perception was evaluated by the short-form McGill pain questionnaire (SF-MPQ), at days 1 and 14. The vascular flow fluctuated similarly in both groups pre- and post-operatively, but the CTG exhibited a more homogeneous pattern as opposed to CMX that showed a second phase of increased blood flow at 14 days. Clinically, the CTG led to greater change in mean root coverage and keratinized tissue gain but CMX was associated with lower early pain intensity scores. Within the limits of the study, the vascular flow alterations during the early healing of both graft types followed a similar pattern. The CMX was associated with a second peak of increased blood flow. The vascular flow changes after the application of CMX for single tooth recession root coverage did not show major differences from those observed after the use of a CTG. A trend for better clinical performance in terms of root coverage and keratinized tissue gain was noted for the CTG, but the initial patient morbidity was less for CMX.

  10. Cerebral demyelination in children with collagenous colitis

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    S Sankararaman

    2013-01-01

    Full Text Available Collagenous colitis (CC is a form of microscopic colitis characterized by the presence of inflammatory infiltrate and subepithelial deposition of collagen in the colon and it is a rare condition with a predominant prevalence in the adult population. Only few cases have been reported in children. We report two children with the CC with concomitant neurological manifestations. Both cases demonstrated variable neurological symptoms clinically and significant cerebral demyelination. In both patients, the gastrointestinal manifestations drastically improved with a short course of prednisolone. However, the neurological symptoms were persistent and progressive. To the best of our knowledge, similar association has not been reported in children.

  11. Gluten-free diet and steroid treatment are effective therapy for most patients with collagenous sprue.

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    Rubio-Tapia, Alberto; Talley, Nicholas J; Gurudu, Suryakanth R; Wu, Tsung-Teh; Murray, Joseph A

    2010-04-01

    Collagenous sprue (CS) is characterized by the presence of a distinctive band of subepithelial collagen deposition in the small bowel. We evaluated the clinical characteristics, treatments, and outcomes of patients with CS. Thirty patients with CS were identified at the 3 Mayo Clinic sites between 1993 and 2009. Clinical data from medical records were reviewed. The study cohort was 70% female (age range, 53-91 years). Most patients had severe diarrhea and weight loss. Hospitalization to treat dehydration was necessary in 16 (53%) patients. Associated immune-mediated diseases were noted in 70% of the patients; celiac disease was the most frequent. Other associated diseases were microscopic colitis, hypothyroidism, and autoimmune enteropathy. The median thickness of the layer of subepithelial collagen deposition in the small bowel was 29 mum (20-56.5 mum). Subepithelial collagen deposition in the colon or stomach was noted in 8 patients. A clinical response was observed in 24 (80%) patients after treatment with a combination of a gluten-free diet and immunosuppressive drugs. Histologic improvement was confirmed in 9 patients, with complete remission in 5. Two patients died (1 of complications of CS and 1 of another illness). Most patients with CS are treated effectively with a combination of gluten-free diet and steroids. CS is often associated with collagen deposition or chronic inflammation in other segments of the gastrointestinal tract as well as other immune-mediated disorders. Copyright 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.

  12. The association between seizures and deposition of collagen in the brain in porcine Taenia solium neurocysticercosis

    DEFF Research Database (Denmark)

    Christensen, Nina Møller; Trevisan, Chiara; Leifsson, Páll Skúli

    2016-01-01

    tissue sections from seven pigs were examined histopathologically i.e. two pigs with epileptic seizures and T. solium cysts, four pigs without seizures but with cysts, and one non-infected control pig. Pigs with epileptic seizures had a larger amount of collagen in their brain tissue, showing as large......Neurocysticercosis caused by infection with Taenia solium is a significant cause of epilepsy and seizures in humans. The aim of this study was to assess the association between seizures and the deposition of collagen in brain tissue in pigs with T. solium neurocysticercosis. In total 78 brain...... fibrotic scars and moderate amount of collagen deposited around cysts, compared to pigs without seizures and the negative control pig. Our results indicate that collagen is likely to play a considerable part in the pathogenesis of seizures in T. solium neurocysticercosis....

  13. The association between seizures and deposition of collagen in the brain in porcine Taenia solium neurocysticercosis.

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    Christensen, Nina M; Trevisan, Chiara; Leifsson, Páll S; Johansen, Maria V

    2016-09-15

    Neurocysticercosis caused by infection with Taenia solium is a significant cause of epilepsy and seizures in humans. The aim of this study was to assess the association between seizures and the deposition of collagen in brain tissue in pigs with T. solium neurocysticercosis. In total 78 brain tissue sections from seven pigs were examined histopathologically i.e. two pigs with epileptic seizures and T. solium cysts, four pigs without seizures but with cysts, and one non-infected control pig. Pigs with epileptic seizures had a larger amount of collagen in their brain tissue, showing as large fibrotic scars and moderate amount of collagen deposited around cysts, compared to pigs without seizures and the negative control pig. Our results indicate that collagen is likely to play a considerable part in the pathogenesis of seizures in T. solium neurocysticercosis. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Teflon Injection into the Trachea Causes Predictable Fibroblastic Response and Collagen Deposition: A Pilot Study.

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    Longoria, Javier A; Fujiwara, Miwa; Guerra, Catalina; Lee, Jeffrey L; Sassoon, Catherine S H; Mazdisnian, Farhad

    2016-10-01

    Expiratory central airway collapse is an increasingly recognized abnormality of the central airways and may be present in as many as 22% of patients evaluated for chronic obstructive pulmonary disease and/or asthma. Many current treatment options require invasive procedures that have been shown to cause significant morbidity and mortality. To test the hypothesis that Teflon injection will induce sufficient fibroblast proliferation and collagen deposition, we evaluated the time course on the effect of Teflon injection in the posterior membranous trachea on the histopathology of the tracheobronchial tree. Six Yucatan Pigs were assigned to undergo general anesthesia and injection of 0.3 to 0.5 mL of sterile Teflon paste in 50% glycerin into the posterior membranous tracheal wall. A control pig received an equivalent volume of glycerin. Animals were euthanized in predefined intervals and tracheas were excised and examined under light microscopy for identifying fibroblast proliferation and collagen deposition. Compared with the control pig, the Teflon injection site showed tissue reaction of fibrohistiocytic proliferation and subsequent collagen deposition in all animals. Furthermore, the increased fibroblast proliferation and collagen deposition were time dependent (PTeflon injection, comprised of increased fibroblast activity and collagen deposition that could be of potential use in creating greater airway rigidity in patients with sever diffuse excessive dynamic airway collapse.

  15. Abnormal deposition of type VII collagen in Kindler syndrome.

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    Wiebe, C B; Larjava, H S

    1999-01-01

    Kindler syndrome is an extremely rare genetic disorder with features of epidermolysis bullosa and poikiloderma congenitale. Approximately 70 cases have been documented in the past 50 years, but only a few investigations of the basement membrane components have been done on these patients. The aim of this study was to examine the components of the basement membrane zone in search of the pathobiological defect(s) responsible for the clinical findings from a female 16-year-old patient diagnosed with Kindler syndrome. This patient also suffered from advanced early-onset periodontal disease. Biopsies were taken from inflamed gingiva and noninflamed oral mucosa as part of periodontal treatment. The basement membrane zone was examined using immunofluorescence microscopy to bullous pemphigoid antigens 1 and 2, collagen types IV and VII, laminins-1 and -5, and integrins alpha3beta1 and alpha6beta4. The biopsies studied revealed blistering with trauma above the level of lamina densa based on distribution of type IV collagen and laminin-1 at the blister floor. In the noninflamed mucosa, discontinuous areas of the basement membrane zone were found. Expression of the basement membrane zone components and the integrins studied appeared otherwise normal with the exception of type VII collagen which was found in abnormal locations deep in the connective tissue stroma. Our results suggest that Kindler syndrome is associated with abnormalities in the construction of the basement membrane, especially in the expression of type VII collagen. These alterations are likely to play a role as etiological factors leading to blister formation and early onset periodontal disease.

  16. Absence of FKBP10 in Recessive Type XI Osteogenesis Imperfecta Leads to Diminished Collagen Cross-Linking and Reduced Collagen Deposition in Extracellular Matrix

    Science.gov (United States)

    Barnes, Aileen M.; Cabral, Wayne A.; Weis, MaryAnn; Makareeva, Elena; Mertz, Edward L.; Leikin, Sergey; Eyre, David; Trujillo, Carlos; Marini, Joan C.

    2012-01-01

    Recessive osteogenesis imperfecta (OI) is caused by defects in genes whose products interact with type I collagen for modification and/or folding. We identified a Palestinian pedigree with moderate and lethal forms of recessive OI caused by mutations in FKBP10 or PPIB, which encode endoplasmic reticulum resident chaperone/isomerases FKBP65 and CyPB, respectively. In one pedigree branch, both parents carry a deletion in PPIB (c.563_566delACAG), causing lethal type IX OI in their two children. In another branch, a child with moderate type XI OI has a homozygous FKBP10 mutation (c.1271_1272delCCinsA). Proband FKBP10 transcripts are 4% of control and FKBP65 protein is absent from proband cells. Proband collagen electrophoresis reveals slight band broadening, compatible with ≈10% overmodification. Normal chain incorporation, helix folding, and collagen Tm support a minimal general collagen chaperone role for FKBP65. However, there is a dramatic decrease in collagen deposited in culture despite normal collagen secretion. Mass spectrometry reveals absence of hydroxylation of the collagen telopeptide lysine involved in cross-linking, suggesting that FKBP65 is required for lysyl hydroxylase activity or access to type I collagen telopeptide lysines, perhaps through its function as a peptidylprolyl isomerase. Proband collagen to organics ratio in matrix is approximately 30% of normal in Raman spectra. Immunofluorescence shows sparse, disorganized collagen fibrils in proband matrix. PMID:22718341

  17. Endoscopic approach to subepithelial lesions.

    Science.gov (United States)

    Menon, Laila; Buscaglia, Jonathan M

    2014-05-01

    Endoscopy and endoscopic ultrasound (EUS) play a critical role in the detection and management of subepithelial lesions of the gastrointestinal tract. The most common subepithelial lesions detected by endoscopists are gastrointestinal stromal tumors (GISTs), leiomyomas, lipomas, granular cell tumors (GCTs), pancreatic rests and carcinoid tumors. These lesions can be classified based on unique histochemical staining and the gastrointestinal layer of origin. While the majority of the lesions are considered benign, some tumors such as GISTs and carcinoids have a strong propensity for malignant transformation. Therefore, appropriate endoscopic versus surgical management based on size and location is crucial in the prevention of malignant transformation and metastasis. In this review, we provide a systematic approach to the diagnosis, management and treatment of commonly encountered subepithelial lesions.

  18. Collagenous sprue: a clinicopathologic study of 12 cases.

    LENUS (Irish Health Repository)

    Maguire, Aoife A

    2012-02-01

    Collagenous sprue is a rare form of small bowel enteropathy characterized by chronic diarrhea and progressive malabsorption with little data available on its natural history. The pathologic lesion consists of subepithelial collagen deposition associated with variable alterations in villous architecture. The small bowel biopsies of 12 cases were reviewed. Clinical details, celiac serology, and T-cell receptor gene rearrangement study results, when available, were collated. There were 8 females and 4 males (age ranged from 41 to 84 y) who presented with chronic diarrhea and weight loss. Small intestinal biopsies showed subepithelial collagen deposition with varying degrees of villous atrophy and varying numbers of intraepithelial lymphocytes. Four patients had previous biopsies showing enteropathic changes without collagen deposition. Seven cases were associated with collagenous colitis and 1 also had features of lymphocytic colitis. Three patients also had collagen deposition in gastric biopsies. One case was associated with lymphocytic gastritis. Celiac disease (CD, gluten-sensitive enteropathy) was documented in 4 patients. Five patients made a clinical improvement with combinations of a gluten-free diet and immunosuppressive therapy. Two patients died of complications of malnutrition and 1 of another illness. Clonal T-cell populations were identified in 5 of 6 cases tested. Four of these patients improved clinically after treatment but 1 has died. Collagenous sprue evolved on a background of CD in 4 cases. There was no history of CD in others and these cases may be the result of a biologic insult other than gluten sensitivity. None has developed clinical evidence of lymphoma to date.

  19. Type V collagen induced tolerance suppresses collagen deposition, TGF-β and associated transcripts in pulmonary fibrosis.

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    Ragini Vittal

    Full Text Available Idiopathic pulmonary fibrosis (IPF is a fatal interstitial lung disease characterized by progressive scarring and matrix deposition. Recent reports highlight an autoimmune component in IPF pathogenesis. We have reported anti-col(V immunity in IPF patients. The objective of our study was to determine the specificity of col(V expression profile and anti-col(V immunity relative to col(I in clinical IPF and the efficacy of nebulized col(V in pre-clinical IPF models.Col(V and col(I expression profile was analyzed in normal human and IPF tissues. C57-BL6 mice were intratracheally instilled with bleomycin (0.025 U followed by col(V nebulization at pre-/post-fibrotic stage and analyzed for systemic and local responses.Compared to normal lungs, IPF lungs had higher protein and transcript expression of the alpha 1 chain of col(V and col(I. Systemic anti-col(V antibody concentrations, but not of anti-col(I, were higher in IPF patients. Nebulized col(V, but not col(I, prevented bleomycin-induced fibrosis, collagen deposition, and myofibroblast differentiation. Col(V treatment suppressed systemic levels of anti-col(V antibodies, IL-6 and TNF-α; and local Il-17a transcripts. Compared to controls, nebulized col(V-induced tolerance abrogated antigen-specific proliferation in mediastinal lymphocytes and production of IL-17A, IL-6, TNF-α and IFN-γ. In a clinically relevant established fibrosis model, nebulized col(V decreased collagen deposition. mRNA array revealed downregulation of genes specific to fibrosis (Tgf-β, Il-1β, Pdgfb, matrix (Acta2, Col1a2, Col3a1, Lox, Itgb1/6, Itga2/3 and members of the TGF-β superfamily (Tgfbr1/2, Smad2/3, Ltbp1, Serpine1, Nfkb/Sp1/Cebpb.Anti-col(V immunity is pathogenic in IPF, and col(V-induced tolerance abrogates bleomycin-induced fibrogenesis and down regulates TGF- β-related signaling pathways.

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

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    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 asthma control all improved (P ≤ 0.02). For patients with severe asthma, 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.

  1. Collagenous sprue: Don't forget connective tissue in chronic diarrhea evaluation

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    Victoria Busto-Bea

    2013-03-01

    Full Text Available Collagenous sprue is a rare disease of the small bowel characterized by mucosal atrophy and excessive subepithelial collagen deposition. The etiology remains unclear and the diagnosis is based upon patient's clinical picture and anatomopathological findings. Clinically, collagenous sprue is characterized by persistent diarrhoea, severe malabsorption, multiple nutrient deficiencies and progressive weight loss. Differential diagnosis includes celiac disease, which is mandatory to rule out because of their frequent association. Gluten-free diet is the first therapeutic step, but it usually is not effective. However, recent studies show high success rates with immunomodulators, mainly corticosteroids. We report the case of a patient presenting with chronic diarrhea and severe malabsorption who was diagnosed with collagenous sprue, with no response to gluten free diet, but with excellent response to budesonida.

  2. Deposition of collagen IV and aggrecan in leptomeningeal arteries of hereditary brain haemorrhage with amyloidosis.

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    Snorradottir, Asbjorg Osk; Isaksson, Helgi J; Kaeser, Stephan A; Skodras, Angelos A; Olafsson, Elias; Palsdottir, Astridur; Bragason, Birkir Thor

    2013-10-16

    Hereditary Cystatin C Amyloid Angiopathy (HCCAA) is a rare genetic disease in Icelandic families caused by a mutation in the cystatin C gene, CST3. HCCAA is classified as a cerebral amyloid angiopathy and mutant cystatin C forms amyloid deposits in cerebral arteries resulting in fatal haemorrhagic strokes in young adults. The aetiology of HCCAA pathology is not clear and there is, at present, no animal model of the disease. The aim of this study was to increase understanding of the cerebral vascular pathology of HCCAA patients with an emphasis on structural changes within the arterial wall of affected leptomeningeal arteries. Examination of post-mortem samples revealed extensive changes in the walls of affected arteries characterised by deposition of extracellular matrix constituents, notably collagen IV and the proteoglycan aggrecan. Other structural abnormalities were thickening of the laminin distribution, intimal thickening concomitant with a frayed elastic layer, and variable reduction in the integrity of endothelia. Our results show that excess deposition of extracellular matrix proteins in cerebral arteries of HCCAA is a prominent feature of the disease and may play an important role in its pathogenesis. © 2013 Elsevier B.V. All rights reserved.

  3. Endotoxemic myocardial dysfunction: subendocardial collagen deposition related to coronary driving pressure.

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    Soriano, Francisco Garcia; Guido, Maria Carolina; Barbeiro, Hermes Vieira; Caldini, Elia Garcia; Lorigados, Clara Batista; Nogueira, Antonio Carlos

    2014-11-01

    Sepsis impairs the autoregulation of myocardial microcirculatory blood flow, but whether this impairment is correlated with myocardial remodeling is unknown. This study investigated the role of coronary driving pressure (CDP) as a determinant of microcirculatory blood flow and myocardial fibrosis in endotoxemia and sepsis. The study is composed of two parts: a prospective experimental study and an observational clinical study. The experimental study was performed on male Wistar rats weighing 300 to 320 g. Endotoxemia was induced in rats by lipopolysaccharide (LPS) injection (10 mg·kg intraperitoneally). Hemodynamic evaluation was performed 1.5 to 24 h after LPS injection by measuring the mean arterial pressure, CDP, left ventricular end-diastolic pressure, dP/dtmax, and dP/dtmin. Microspheres were also infused into the left ventricle to measure myocardial blood flow, and myocardial tissue was histologically assessed to analyze collagen deposition. The CDP, mean arterial pressure, and myocardial blood flow were reduced by 55%, 30%, and 70%, respectively, in rats 1.5 h after LPS injection compared with phosphate buffer saline injection (P subendocardial blood flow (r = 0.73) and fibrosis (r = 0.8). Left ventricular function was significantly impaired in the LPS-treated rats, as demonstrated by dP/dtmax (6,155 ± 455 vs. 3,746 ± 406 mmHg·s, baseline vs. LPS; P subendocardial blood flow was positively correlated with CDP, and higher CDP was negatively correlated with myocardial collagen deposition. Thus, early reductions in myocardial blood flow and CDP facilitate late myocardial fibrosis in rats and likely in humans.

  4. Mesothelial Cell Autoantibodies Induce Collagen Deposition in vitro & Using a Case Study to Introduce Undergraduates to Bioinformatics

    Science.gov (United States)

    Serve, Kinta M.

    2013-01-01

    Part I. Pleural fibrosis, a non-malignant, asbestos-related respiratory disease characterized by excessive collagen deposition, is progressive, debilitating, and potentially fatal. Disease severity may be influenced by the type of asbestos fiber inhaled, with Libby amphibole (LA) a seemingly more potent mediator of pleural fibrosis than chrysotile…

  5. Pseudomembranous collagenous colitis with superimposed drug damage.

    Science.gov (United States)

    Villanacci, Vincenzo; Cristina, Silvia; Muscarà, Maurizio; Saettone, Silvia; Broglia, Laura; Antonelli, Elisabetta; Salemme, Marianna; Occhipinti, Pietro; Bassotti, Gabrio

    2013-11-01

    Pseudomembranous collagenous colitis is a rare pathological condition, not related to infectious agents, and characterized by thickening of the subepithelial collagen and formation of pseudomembranes. We report one such case, which responded to budesonide treatment after failures of previous approaches given, being unaware of the correct diagnosis. Copyright © 2013 Elsevier GmbH. All rights reserved.

  6. Collagenous Gastritis: A Rare Entity

    Directory of Open Access Journals (Sweden)

    Faten Limaiem

    2015-06-01

    Full Text Available Collagenous gastritis is a rare entity of unknown etiology characterized histologically by the presence of a thick subepithelial collagen band associated with an inflammatory infiltrate of gastric mucosa. A 40-year-old male presented with a history of chronic intermittent abdominal pain for about 6 months. Physical examination was unremarkable, and biological tests were within normal range. The patient underwent esophagogastroduodenoscopy and colonoscopy which showed a nodular mucosa of the stomach. Biopsies of the duodenum and colon were unremarkable. However, biopsies of the gastric fundus revealed a mild chronic gastritis characterized by lymphocytic and plasma cell infiltration of deep mucosa, without lymphoid follicle formation or active inflammation. No microorganisms were identified on routine hematoxylin and eosin or Giemsa-stained sections. Subepithelial collagen in the gastric biopsies was thickened and showed entrapped capillaries. Subepithelial collagen was highlighted by Masson's trichrome staining and was negative for amyloid by Congo Red. In the areas containing thickened collagen, there were no intraepithelial lymphocytes. The final pathological diagnosis was collagenous gastritis. Collagenous gastritis is an extremely rare disease, but it is important to recognize its characteristic endoscopic and pathologic findings to make a correct diagnosis. Specific therapy for this rare entity has not yet been established. [J Interdiscipl Histopathol 2015; 3(2.000: 68-70

  7. Automated image analysis in the study of collagenous colitis

    DEFF Research Database (Denmark)

    Fiehn, Anne-Marie Kanstrup; Kristensson, Martin; Engel, Ulla

    2016-01-01

    PURPOSE: The aim of this study was to develop an automated image analysis software to measure the thickness of the subepithelial collagenous band in colon biopsies with collagenous colitis (CC) and incomplete CC (CCi). The software measures the thickness of the collagenous band on microscopic...

  8. Immunogold fine structural localization of extracellular matrix components in aged human cornea. II. Collagen types V and VI.

    Science.gov (United States)

    Marshall, G E; Konstas, A G; Lee, W R

    1991-01-01

    Using immunogold immunocytochemical techniques we studied the distribution of collagen types V and VI in corneal tissue from seven enucleated human eyes (age range, 63-78 years). Results obtained by cryoultramicrotomy were marginally more intense than those obtained using London Resin white (LR white) embedding. Type V collagen was present in the striated collagen fibrils in Bowman's layer, in the stroma and in a thin, non-banded anterior zone of Descemet's membrane. Our results suggest that types I, III and V collagen co-distribute in striated collagen fibrils. By contrast, type VI collagen was located in fine filaments in the interfibrillar matrix of the stroma, in Bowman's layer and in the anchoring plaques of the sub-epithelial basement-membrane complex. This implies an importance in epithelial adhesion which was previously unsuspected. Keratocyte bodies were electron-dense, amorphous extracellular deposits of matrix-like material, and these were labelled with types III, V and VI collagen antibodies. Long-spacing collagen was observed in the corneal stroma, and this deposit did not contain any of the collagen types studied.

  9. Abnormal deposition of laminin and type IV collagen at corneal epithelial basement membrane during wound healing in diabetic rats.

    Science.gov (United States)

    Sato, N; Nakamura, M; Chikama, T; Nishida, T

    1999-01-01

    To understand the pathophysiology of the corneal basement membrane in diabetes, we compared the localization of laminin and type IV collagen in the epithelial basement membrane during corneal epithelial wound healing in diabetic and nondiabetic rats. Streptozotocin was used to induce diabetes in half the rats. Two weeks later, the whole corneal epithelium was debrided. Diabetic and healthy rats (3-5 per group) were sacrificed before debridement and 1, 3, and 7 days and 1 month afterwards. The localization of laminin and type IV collagen was observed in cryosections by epifluorescence microscopy. In unwounded corneas of both diabetic and normal rats, laminin and type IV collagen were localized in the corneal epithelial basement. The intensity of fluorescence, however, was clearly stronger in the diabetic rats. In normal rats, wounding initially removed laminin and type IV collagen, but during healing these two proteins reappeared beneath the resurfacing corneal epithelium. Although similar results were observed in diabetic rats, the expression of laminin and type IV collagen was delayed, and their deposition was fragmented and irregular. These results suggest that delayed corneal epithelial wound healing in diabetes might involve delayed reappearance and abnormal reformation of epithelial basement membrane proteins.

  10. Predictive features for histology of gastric subepithelial lesions

    OpenAIRE

    SCHULZ, Ricardo Teles; FABIO, Lizandra Castilho; FRANCO, Matheus Cavalcante; SIQUEIRA, Sheila A; SAKAI, Paulo; MALUF-FILHO, Fauze

    2017-01-01

    ABSTRACT BACKGROUND Gastric subepithelial lesion is a relatively common diagnosis after routine upper endoscopy. The diagnostic workup of an undetermined gastric subepithelial lesion should take into consideration clinical and endoscopic features. OBJECTIVE We aimed to investigate the association between patients' characteristics, endoscopic and echographic features with the histologic diagnosis of the gastric subepithelial lesions. METHODS This is a retrospective study with 55 patients, w...

  11. Collagen fibril assembly in the developing avian primary corneal stroma.

    Science.gov (United States)

    Fitch, J M; Linsenmayer, C M; Linsenmayer, T F

    1994-03-01

    The primary stroma of the developing avian cornea is a highly organized extracellular matrix composed largely of striated collagen fibrils synthesized by the epithelium. These fibrils are heterotypic structures consisting of at least two different fibrillar collagen types (I and II) and probably a fibril-associated collagen (type IX). The epithelial derivation and vectorial secretion of the components of this matrix provide an advantageous system to study the steps in the assembly of this developmentally regulated matrix, as well as in the assembly and maturation of heterotypic collagen fibrils in general. To ascertain when and where two of the collagens of the primary stroma (collagen types II and IX) are assembled into fibrils, monoclonal antibodies were used that bind to the newly deposited, "immature" (non-cross-linked) forms of these molecules, but not to ones that have been assembled into fibrils and have become cross-linked. The patterns of immunoreactivity for newly deposited versus total collagens were compared by immunofluorescence histochemistry on sections of corneas from developing chicken embryos. Pretreatments that affect collagen cross-linking and enzymatic digestions with collagenase also were used. In early corneas, immunoreactivity for the newly deposited forms of both collagen types II and IX was confined to a narrow subepithelial zone, their epitopes being masked in the deeper layers of the stroma. The masked immunoreactivity could be exposed in these layers by inhibiting cross-link formation with beta-aminopropionitrile. At later developmental stages, after the stroma has swollen and become invaded by mesenchymal cells, type IX collagen is no longer detectable either as an "immature" or as a fibril-associated form. During most of this period, the distribution of "immature" type II collagen is noticeably more restricted to the subepithelial zone than is total type II. Much of the undetectable immunoreactivity for collagen type II could be

  12. Hyperglycemic condition during puberty increases collagen fibers deposition in the prostatic stroma and reduces MMP-2 activity.

    Science.gov (United States)

    Santos, Sérgio Alexandre Alcantara Dos; Porto Amorim, Elaine Manoela; Ribeiro, Larissa Mayume; Rinaldi, Jaqueline Carvalho; Delella, Flávia Karina; Justulin, Luis Antonio; Felisbino, Sérgio Luis

    2017-12-02

    Puberty is an important period for the growth and maturation of the male reproductive system, and is also a critical window for endocrine or environmental interference. The physiological levels of circulating insulin and hyperglycemic control are important factors for a normal prostate growth. Hyperglycemia during puberty is reported to retard the growth of the prostate gland, with remarkable effects on the epithelial compartment. Here, we investigated the impact of hyperglycemia along with a simultaneous or late insulin replacement on the ventral prostate growth in rats during puberty, paying special attention to the deposition of collagen fibers and activities of gelatinase, matrix metalloproteinase-2 (MMP-2), and -9 (MMP-9). Hyperglycemia was induced by streptozotocin (STZ) administration in 40-day-old male Wistar rats. A subset of hyperglycemic rats underwent an early insulin replacement (three days after the STZ administration), and another subset underwent a late insulin replacement (twenty days after the STZ administration). Animals were euthanized at 60 and/or 80 days of age. The ventral prostatic lobe was processed for picrosirius red staining, type I and III collagen immunohistochemistry, and gelatin zymography. Hyperglycemic animals showed an increased area of collagen fibers in the prostate, which was composed both types of collagens. MMP-2 activity was significantly reduced in the hyperglycemic animals, while MMP-9 activity was very low and showed no alteration. The simultaneous and late insulin administration restored collagen content and MMP-2 activity. In conclusion, puberty is a critical window for prostate maturation and type-1 diabetes-induced hyperglycemia affects the ratio of the prostatic parenchymal and stromal growth, leading to fibrotic tissues by also MMP-2 down regulation. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Subepithelial connective tissue graft: a case report

    OpenAIRE

    Juliana Alcarás Saraiva; Edson Alves de Campos; Rodrigo Cavassim; Shelon Cristina de Souza Pinto; Lucas Amaral Fontanari; Guilherme José Pimentel Lopes Oliveira; José Eduardo Cezar Sampaio

    2011-01-01

    Introduction and objective: Marginal tissue recession represents a common condition in Periodontology. Miller's Classes I and II recessions, in which the etiological factors are well diagnosed and eliminated, show great predictability of total coverage when the technique of subepithelial connective tissue graft is used. This technique success has been mainly attributed to the double blood supply for graft's nutrition, originating from the connective tissue of both the periosteum and flap. Cas...

  14. Detection of subepithelial fibrosis associated with corneal stromal edema by second harmonic generation imaging microscopy.

    Science.gov (United States)

    Morishige, Naoyuki; Yamada, Naoyuki; Teranishi, Shinichiro; Chikama, Tai-ichiro; Nishida, Teruo; Takahara, Atsushi

    2009-07-01

    Human corneas with or without stromal edema were examined by second harmonic generation (SHG) imaging microscopy to characterize stromal collagen organization. Tissue buttons from 31 corneas with stromal edema and 8 normal corneas were fixed, and 3-mm(2) blocks were cut and stained with phalloidin, to visualize the cytoskeleton. The blocks were examined by SHG imaging with a laser confocal microscope and a mode-locked titanium:sapphire femtosecond laser. Samples were scanned to a depth of 150 microm from the surface of Bowman's layer, and SHG forward- and backscatter signals were collected. Phalloidin staining was detected by conventional laser confocal microscopy. The three-dimensional structure of the anterior segment of the cornea was reconstructed from stacked SHG images. Three-dimensional reconstruction of SHG signals showed adherence of interwoven collagen lamellae in the anterior stroma to Bowman's layer in both normal and edematous corneas. Abnormal SHG signals at the level of Bowman's layer were observed in edematous corneas; three-dimensional images revealed that these signals were actually localized above Bowman's layer and were indicative of subepithelial fibrosis. Phalloidin staining showed transdifferentiation of stromal cells into fibroblastic cells in edematous corneas. The incidence of subepithelial fibrosis or of fibroblastic cells increased beginning 12 months after the onset of clinical stromal edema. SHG imaging of the anterior segment of edematous corneas revealed a normal appearance of interwoven collagen lamellae in the anterior stroma. The development of subepithelial fibrosis beginning 12 months after the onset of edema suggests that stromal edema may be a progressive disease.

  15. Histologic and Clinical Study of Gingival Recession Treated with Subepithelial Connective Tissue Graft: A Case Report.

    Science.gov (United States)

    García-De-la-Fuente, Ana-María; Aguirre-Zorzano, Luis Antonio; Estefanía-Fresco, Ruth; Roig Ódena, Laia; Aguirre-Urizar, José-Manuel

    Subepithelial connective tissue graft (SCTG) is considered the gold standard for treatment of gingival recessions. For ethical reasons, most studies report only clinical and not histologic results. A 20-year-old woman presenting with a localized gingival recession of 5 mm in the mandibular left central incisor was treated with SCTG. According to the initial treatment plan, the tooth was extracted 11 months later and a histologic study was performed, revealing new attachment of connective tissue with collagen fibers that were directly inserted in a perpendicular way into dentin areas and new cement areas (1.37 mm).

  16. A Comparative Clinicopathologic Study of Collagenous Gastritis in Children and Adults: The Same Disorder With Associated Immune-mediated Diseases.

    Science.gov (United States)

    Ma, Changqing; Park, Jason Y; Montgomery, Elizabeth A; Arnold, Christina A; McDonald, Oliver G; Liu, Ta-Chiang; Salaria, Safia N; Limketkai, Berkeley N; McGrath, Kevin M; Musahl, Tina; Singhi, Aatur D

    2015-06-01

    Collagenous gastritis is a rare condition characterized by surface epithelial damage, subepithelial collagen deposition, and a lamina propria inflammatory infiltrate. Previous studies have proposed 2 clinicopathologic subtypes: (1) children (18 y of age or younger) presenting with severe anemia, nodular gastric mucosa, and isolated gastric disease; and (2) adults with chronic watery diarrhea that is associated with diffuse collagenous involvement of the gastrointestinal tract. However, notable exceptions exist. In fact, broad variability in clinical presentation, etiology, treatment and disease course has been reported. To better define the clinicopathologic features of collagenous gastritis, we have collected 10 pediatric and 21 adult cases and describe their clinical, endoscopic, pathologic, and follow-up findings. Both children and adults presented with similar clinical symptoms such as anemia (50%, 35%, respectively), epigastric/abdominal pain (50%, 45%), and diarrhea (40%, 55%). Concomitant immune disorders were identified in 2 (20%) children and 3 (14%) adults. Further, 7 of 17 (41%) adults were taking medications associated with other immune-related gastrointestinal diseases including olmesartan and antidepressants. Histologically, there were no differences between children and adults with collagenous gastritis in the location of gastric involvement, mean collagenous layer thickness, and prominence of eosinophils (P>0.05). Extragastric collagenous involvement was also seen with comparable frequencies in each cohort (44%, 59%). Follow-up information was available for 22 of 31 (71%) patients and ranged from 2 to 122 months (mean, 33.6 mo). Despite medical management in most cases, persistence of symptoms or collagenous gastritis on subsequent biopsies was seen in 100% of children and 82% of adults. Of note, treatment for 1 adult patient involved cessation of olmesartan resulting in resolution of both symptoms and subepithelial collagen deposition on subsequent

  17. Mesothelial Cell Autoantibodies Induce Collagen Deposition in vitro & Using a Case Study to Introduce Undergraduates to Bioinformatics

    Science.gov (United States)

    Serve, Kinta M.

    Part I. Pleural fibrosis, a non-malignant, asbestos-related respiratory disease characterized by excessive collagen deposition, is progressive, debilitating, and potentially fatal. Disease severity may be influenced by the type of asbestos fiber inhaled, with Libby amphibole (LA) a seemingly more potent mediator of pleural fibrosis than chrysotile (CH) asbestos. This difference in severity may be due to the reported immunological component associated with LA but not CH related diseases. Here, we report the potential mechanisms by which asbestos-associated mesothelial cell autoantibodies (MCAAs) contribute to pleural fibrosis development. MCAAs are shown to bind cultured human pleural mesothelial cells and induce the deposition of type I collagen proteins in the absence of phenotypic changes typically associated with fibrosis development. However, additional extracellular proteins seem to differentially contribute to LA and CH MCAA-associated collagen deposition. Our data also suggest that IgG subclass distributions differ between LA and CH MCAAs, potentially altering the antibody effector functions. Differences in MCAA mechanisms of action and effector functions may help explain the disparate clinical disease phenotypes noted between LA and CH-exposed populations and may provide insights for development of novel therapeutic strategies. Part II. As scientific research becomes increasingly reliant on computational tools, it is more important than ever before to train students to use these tools. While educators agree that biology students should gain experience with bioinformatics, there exists no consensus as to how to integrate these concepts into the already demanding undergraduate curriculum. The Portal-21 project offers a solution by utilizing on-line learning case studies to allow flexibility for classroom integration. Presented here are the results from two field tests of a case study developed to introduce the common bioinformatics tools pBLAST and PubMed to

  18. Arginase inhibition prevents bleomycin-induced pulmonary hypertension, vascular remodeling, and collagen deposition in neonatal rat lungs.

    Science.gov (United States)

    Grasemann, Hartmut; Dhaliwal, Rupinder; Ivanovska, Julijana; Kantores, Crystal; McNamara, Patrick J; Scott, Jeremy A; Belik, Jaques; Jankov, Robert P

    2015-03-15

    Arginase is an enzyme that limits substrate L-arginine bioavailability for the production of nitric oxide by the nitric oxide synthases and produces L-ornithine, which is a precursor for collagen formation and tissue remodeling. We studied the pulmonary vascular effects of arginase inhibition in an established model of repeated systemic bleomycin sulfate administration in neonatal rats that results in pulmonary hypertension and lung injury mimicking the characteristics typical of bronchopulmonary dysplasia. We report that arginase expression is increased in the lungs of bleomycin-exposed neonatal rats and that treatment with the arginase inhibitor amino-2-borono-6-hexanoic acid prevented the bleomycin-induced development of pulmonary hypertension and deposition of collagen. Arginase inhibition resulted in increased L-arginine and L-arginine bioavailability and increased pulmonary nitric oxide production. Arginase inhibition also normalized the expression of inducible nitric oxide synthase, and reduced bleomycin-induced nitrative stress while having no effect on bleomycin-induced inflammation. Our data suggest that arginase is a promising target for therapeutic interventions in neonates aimed at preventing lung vascular remodeling and pulmonary hypertension. Copyright © 2015 the American Physiological Society.

  19. Collagenous gastritis: a morphologic and immunohistochemical study of 40 patients.

    Science.gov (United States)

    Arnason, Thomas; Brown, Ian S; Goldsmith, Jeffrey D; Anderson, William; O'Brien, Blake H; Wilson, Claire; Winter, Harland; Lauwers, Gregory Y

    2015-04-01

    Collagenous gastritis is a rare condition defined histologically by a superficial subepithelial collagen layer. This study further characterizes the morphologic spectrum of collagenous gastritis by evaluating a multi-institutional series of 40 patients (26 female and 14 male). The median age at onset was 16 years (range 3-89 years), including 24 patients (60%) under age 18. Twelve patients (30%) had associated celiac disease, collagenous sprue, or collagenous colitis. Hematoxylin and eosin slides were reviewed in biopsies from all patients and tenascin, gastrin, eotaxin, and IgG4/IgG immunohistochemical stains were applied to a subset. The distribution of subepithelial collagen favored the body/fundus in pediatric patients and the antrum in adults. There were increased surface intraepithelial lymphocytes (>25 lymphocytes/100 epithelial cells) in five patients. Three of these patients had associated celiac and/or collagenous sprue/colitis, while the remaining two had increased duodenal lymphocytosis without specific etiology. An eosinophil-rich pattern (>30 eosinophils/high power field) was seen in 21/40 (52%) patients. Seven patients' biopsies demonstrated atrophy of the gastric corpus mucosa. Tenascin immunohistochemistry highlighted the subepithelial collagen in all 21 specimens evaluated and was a more sensitive method of collagen detection in biopsies from two patients with subtle subepithelial collagen. No increased eotaxin expression was identified in 16 specimens evaluated. One of the twenty-three biopsies tested had increased IgG4-positive cells (100/high power field) with an IgG4/IgG ratio of 55%. In summary, collagenous gastritis presents three distinct histologic patterns including a lymphocytic gastritis-like pattern, an eosinophil-rich pattern, and an atrophic pattern. Eotaxin and IgG4 were not elevated enough to implicate these pathways in the pathogenesis. Tenascin immunohistochemistry can be used as a sensitive method of collagen detection.

  20. Predictive features for histology of gastric subepithelial lesions

    Directory of Open Access Journals (Sweden)

    Ricardo Teles SCHULZ

    Full Text Available ABSTRACT BACKGROUND Gastric subepithelial lesion is a relatively common diagnosis after routine upper endoscopy. The diagnostic workup of an undetermined gastric subepithelial lesion should take into consideration clinical and endoscopic features. OBJECTIVE We aimed to investigate the association between patients' characteristics, endoscopic and echographic features with the histologic diagnosis of the gastric subepithelial lesions. METHODS This is a retrospective study with 55 patients, who were consecutively diagnosed with gastric subepithelial lesions, from October 2008 to August 2011. Patients' characteristics, endoscopic and echografic features of each gastric subepithelial lesion were analysed. Histologic diagnosis provided by EUS-guided fine needle aspiration or endoscopic/surgical resection was used as gold standard. RESULTS The probability of gastrointestinal stromal tumors to be located in the cardia was low (4.5%, while for leiomyoma it was high (>95%. In addition, there was a higher risk of gastrointestinal stromal tumors in patients older than 57 years (OR 8.9; 95% CI, with lesions ≥21 mm (OR 7.15; 95% CI, located at 4th layer (OR 18.8; 95% CI, with positive Doppler sign (OR 9; 95% CI, and irregular outer border (OR 7.75; 95% CI. CONCLUSION The location of gastric subepithelial lesions in the gastric cardia lowers the risk of gastrointestinal stromal tumors. While gastric subepithelial lesions occurring in elderly patients, located in the gastric body, with positive Doppler signal and irregular outer border increase the risk of gastrointestinal stromal tumors.

  1. Endocytic collagen degradation

    DEFF Research Database (Denmark)

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

    2012-01-01

    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...

  2. Auxiliary proteins that facilitate formation of collagen-rich deposits in the posterior knee capsule in a rabbit-based joint contracture model.

    Science.gov (United States)

    Steplewski, Andrzej; Fertala, Jolanta; Beredjiklian, Pedro K; Abboud, Joseph A; Wang, Mark L Y; Namdari, Surena; Barlow, Jonathan; Rivlin, Michael; Arnold, William V; Kostas, James; Hou, Cheryl; Fertala, Andrzej

    2016-03-01

    Post-traumatic joint contracture is a debilitating consequence of trauma or surgical procedures. It is associated with fibrosis that develops regardless of the nature of initial trauma and results from complex biological processes associated with inflammation and cell activation. These processes accelerate production of structural elements of the extracellular matrix, particularly collagen fibrils. Although the increased production of collagenous proteins has been demonstrated in tissues of contracted joints, researchers have not yet determined the complex protein machinery needed for the biosynthesis of collagen molecules and for their assembly into fibrils. Consequently, the purpose of our study was to investigate key enzymes and protein chaperones needed to produce collagen-rich deposits. Using a rabbit model of joint contracture, our biochemical and histological assays indicated changes in the expression patterns of heat shock protein 47 and the α-subunit of prolyl 4-hydroxylase, key proteins in processing nascent collagen chains. Moreover, our study shows that the abnormal organization of collagen fibrils in the posterior capsules of injured knees, rather than excessive formation of fibril-stabilizing cross-links, may be a key reason for observed changes in the mechanical characteristics of injured joints. This result sheds new light on pathomechanisms of joint contraction, and identifies potentially attractive anti-fibrotic targets. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  3. 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

  4. Synchronous Occurrence of Collagenous and Pseudomembranous Colitis

    Directory of Open Access Journals (Sweden)

    Z Vesoulis

    2000-01-01

    Full Text Available Synchronous collagenous and pseudomembranous colitis has not been previously reported. A 73-year-old woman presented with chronic watery diarrhea and abdominal cramping of six weeks’ duration. Biopsies of the colon revealed findings of collagenous colitis involving the endoscopically normal right colon, and superimposed collagenous and pseudomembranous colitis involving the rectosigmoid colon. Endoscopically, the left colon revealed discrete ulcerative plaques, and Clostridium difficile toxin A assay was positive. The patient partially responded to a three-week regimen of metronidazole, and symptoms resolved completely with subsequent steroid therapy. At follow-up endoscopy four months later, colon biopsies demonstrated persistence of subepithelial collagen but no pseudomembranes. The patient remained asymptomatic during this interval. Collagenous colitis has been reported in association with other inflammatory bowel diseases, including lymphocytic colitis, sprue and idiopathic inflammatory bowel disease. This unique association of collagenous colitis with an endotoxigenic inflammatory bowel disease is presented with a review of related disease features.

  5. Patterns of production of collagen-rich deposits in peripheral nerves in response to injury: A pilot study in a rabbit model.

    Science.gov (United States)

    Rivlin, Michael; Miller, Andrew; Tulipan, Jacob; Beredjiklian, Pedro K; Wang, Mark L; Fertala, Jolanta; Steplewski, Andrzej; Kostas, James; Fertala, Andrzej

    2017-07-01

    Although collagen-rich deposits are the main component of neural scars, the patterns of their formation are ill defined. Essential to the biosynthesis of collagen fibrils are enzymes catalyzing posttranslational modifications and chaperones that control the formation of the collagen triple helix. Prolyl-4-hydroxylase (P4H) and heat shock protein-47 (HSP47) play a key role, and their production is upregulated during scar formation in human tissues. Alpha smooth muscle actin (αSMA) is also produced during fibrotic processes in myofibroblasts that participate in fibrotic response. In injured peripheral nerves, however, the distribution of cells that produce these markers is poorly understood. The goal of this study was to determine the distribution of the αSMA-positive, HSP47-positive, and the P4H-positive cells to better understand the formation of collagen-rich fibrotic tissue (FT) in response to peripheral nerve injury. To reach this goal, we employed a rabbit model of crush-injury and partial-transection injury of the sciatic nerves. Our study demonstrated that αSMA is expressed in a relatively small number of cells seen in neural FT. In contrast, cells producing P4H and HSP47 are ubiquitously present in sites of injury of the sciatic nerves. We contemplate that these proteins may serve as valuable markers that define fibrotic activities in the injured peripheral nerves.

  6. Clinical evaluation of subepithelial connective tissue graft and guided tissue regeneration for treatment of Miller’s class 1 gingival recession (comparative, split mouth, six months study)

    Science.gov (United States)

    Bhavsar, Neeta-V.; Dulani, Kirti; Trivedi, Rahul

    2014-01-01

    Objectives: The present study aims to clinically compare and evaluate subepithelial connective tissue graft and the GTR based root coverage in treatment of Miller’s Class I gingival recession. Study Design: 30 patients with at least one pair of Miller’s Class I gingival recession were treated either with Subepithelial connective tissue graft (Group A) or Guided tissue regeneration (Group B). Clinical parameters monitored included recession RD, width of keratinized gingiva (KG), probing depth (PD), clinical attachment level (CAL), attached gingiva (AG), residual probing depth (RPD) and % of Root coverage(%RC). Measurements were taken at baseline, three months and six months. A standard surgical procedure was used for both Group A and Group B. Data were recorded and statistical analysis was done for both intergroup and intragroup. Results: At end of six months % RC obtained were 84.47% (Group A) and 81.67% (Group B). Both treatments resulted in statistically significant improvement in clinical parameters. When compared, no statistically significant difference was found between both groups except in RPD, where it was significantly greater in Group A. Conclusions: GTR technique has advantages over subepithelial connective tissue graft for shallow Miller’s Class I defects and this procedure can be used to avoid patient discomfort and reduce treatment time. Key words:Collagen membrane, comparative split mouth study, gingival recession, subepithelial connective tissue graft, guided tissue regeneration (GTR). PMID:25136420

  7. Clinical evaluation of subepithelial connective tissue graft and guided tissue regeneration for treatment of Miller's class 1 gingival recession (comparative, split mouth, six months study).

    Science.gov (United States)

    Trivedi, Sakshee-R; Bhavsar, Neeta-V; Dulani, Kirti; Trivedi, Rahul

    2014-07-01

    The present study aims to clinically compare and evaluate subepithelial connective tissue graft and the GTR based root coverage in treatment of Miller's Class I gingival recession. 30 patients with at least one pair of Miller's Class I gingival recession were treated either with Subepithelial connective tissue graft (Group A) or Guided tissue regeneration (Group B). Clinical parameters monitored included recession RD, width of keratinized gingiva (KG), probing depth (PD), clinical attachment level (CAL), attached gingiva (AG), residual probing depth (RPD) and % of Root coverage(%RC). Measurements were taken at baseline, three months and six months. A standard surgical procedure was used for both Group A and Group B. Data were recorded and statistical analysis was done for both intergroup and intragroup. At end of six months % RC obtained were 84.47% (Group A) and 81.67% (Group B). Both treatments resulted in statistically significant improvement in clinical parameters. When compared, no statistically significant difference was found between both groups except in RPD, where it was significantly greater in Group A. GTR technique has advantages over subepithelial connective tissue graft for shallow Miller's Class I defects and this procedure can be used to avoid patient discomfort and reduce treatment time. Key words:Collagen membrane, comparative split mouth study, gingival recession, subepithelial connective tissue graft, guided tissue regeneration (GTR).

  8. [Glycosaminoglycans in subepithelial opacity after excimer laser keratectomy].

    Science.gov (United States)

    Nakayasu, K; Gotoh, T; Ishikawa, T; Kanai, A

    1996-05-01

    We evaluated histochemically the characteristics of glycosaminoglycans and proteoglycans in the corneal subepithelial opacity after excimer laser keratectomy on rabbit corneas. We also performed the same evaluations on the cornea after mechanical keratectomy. Twenty days after the operations, the area immediately subjacent to the epithelium showed strong staining with toluidine blue, alcian blue, and colloidal iron. However, after treatment with chondroitinase ABC or chondroitinase AC, alcian blue staining in this area decreased dramatically. Antilarge proteoglycan antibody also reacted strongly in this area. Histochemical and immunohistochemical examination of the cornea where mechanical keratectomy was done showed basically similar findings with the cornea of excimer laser keratectomy. These results suggest that large-molecula proteoglycans with chondroitine sulfate side chains become localized in the subepithelial area after two different kinds of keratectomies. We presume from histochemical and immunohistochemical observations that the subepithelial opacity observed after excimer laser keratectomy is not a special reaction to excimer laser but simply a corneal scar formed after stromal resection.

  9. Polyvinylidene fluoride for proliferation and preservation of bovine corneal endothelial cells by enhancing type IV collagen production and deposition.

    Science.gov (United States)

    Wang, Tsung-Jen; Wang, I-Jong; Chen, Yi-Hsin; Lu, Jui-Nan; Young, Tai-Horng

    2012-01-01

    In this study, biomaterials with different hydrophobic properties including polyvinyl alcohol (PVA), poly(ethylene-co-vinyl alcohol) (EVAL), tissue culture polystyrene (TCPS), and polyvinylidene fluoride (PVDF) were examined in the bovine corneal endothelial cells (BCECs) culture system to elucidate their possible impact on clinical demand and scientific interest. It was found that BCECs were inhibited to attach onto the PVA surface. Conversely, relatively more hydrophobic biomaterials EVAL, TCPS, and PVDF successfully initiate BCEC adhesion. Compared to EVAL, cultured BCECs on TCPS and PVDF exhibited higher viability. Furthermore, fibroblastic transformation on EVAL and TCPS was observed at day 17, but BCECs maintained typical hexagonal shape on the PVDF surface at day 21. This phenomenon can be rescued by previously coating type IV collagen on TCPS but not on EVAL. In addition, when BCECs were cultured on PVDF, the expressions of gap junction connexin-43, differentiation marker N-cadherin, and tight junction ZO-1 were well-developed, resembling the physiological phenotypes. After examining the type IV collagen expression by Western blot analysis and protein absorption test, a possible explanation for the better proliferation and preservation of BCECs on the PVDF substrate is that PVDF is a bioactive substratum which enables BCECs to synthesize and reserve more extracellular matrix type IV collagen, paving an important way to provide a more preferential environment for BCEC cultures. Accordingly, promoting CEC growth effects after cell-biomaterial association may be applied to the tissue engineering of corneal endothelium. Copyright © 2011 Wiley Periodicals, Inc.

  10. Modified single incision technique to harvest subepithelial connective tissue graft.

    Science.gov (United States)

    Kumar, Ashish; Sood, Vishal; Masamatti, Sujata Surendra; Triveni, M G; Mehta, D S; Khatri, Manish; Agarwal, Vipin

    2013-09-01

    Dental therapy in general and periodontal therapy in particular is directed increasingly at the esthetic outcome for patients. Gingival recession is one of the most common esthetic concerns associated with periodontal tissues. Although various treatment modalities have been developed, subepithelial connective tissue grafting remains the most successful and predictable technique for treatment of gingival recession. Harvesting a connective tissue graft from the palate is many times not only traumatic, but also very painful for the patient. Use of single incision to harvest the subepithelial connective tissue graft is one of the least traumatic, but relatively difficult technique to accomplish. This article presents a modified single incision technique, which is not only less traumatic and painful, but comparatively simple to employ and master. Two new instruments have been introduced to make harvesting of the connective tissue graft easier.

  11. Clinical evaluation of papilla reconstruction using subepithelial connective tissue graft.

    Science.gov (United States)

    Kaushik, Alka; Pk, Pal; Jhamb, Kshitij; Chopra, Deepak; Chaurasia, Vishwajit Rampratap; Masamatti, Vinaykumar S; Dk, Suresh; Babaji, Prashant

    2014-09-01

    The aesthetics of the patient can be improved by surgical reconstruction of interdental papilla by using an advanced papillary flap interposed with subepithelial connective tissue graft. A total of fifteen sites from ten patients having black triangles/papilla recession in the maxillary anterior region were selected and subjected to presurgical evaluation. The sites were treated with interposed subepithelial connective tissue graft placed under a coronally advance flap. The integrity of the papilla was maintained by moving the whole of gingivopapillary unit coronally. The various parameters were analysed at different intervals. There was a mean decrease in the papilla presence index score and distance from contact point to gingival margin, but it was statistically not significant. Also, there is increase in the width of the keratinized gingiva which was statistically highly significant. Advanced papillary flap with interposed sub-epithelial connective tissue graft can offer predictable results for the reconstruction of interdental papilla. If papilla loss occurs solely due to soft-tissue damage, reconstructive techniques can completely restore it; but if due to periodontal disease involving bone loss, reconstruction is generally incomplete and multiple surgical procedures may be required.

  12. Total polysaccharide of Yupingfeng protects against bleomycin-induced pulmonary fibrosis via inhibiting transforming growth factor-β1-mediated type I collagen abnormal deposition in rats.

    Science.gov (United States)

    Xu, Liang; Li, Liu-cheng; Zhao, Ping; Qi, Lian-wen; Li, Ping; Gao, Jian; Fei, Guang-he

    2014-12-01

    This study was to explore the antifibrotic effect and the possible mechanism of total polysaccharides of Yupingfeng (YPF-P) on bleomycin (BLM)-induced pulmonary fibrosis in rats. Pulmonary fibrosis was induced in Sprague-Dawley rats by BLM (5 mg/kg), killed 14 and 28 days after BLM administration by abdominal aorta exsanguination and removed the lungs. Lung coefficient was counted at the same time. Besides, H&E and Masson's trichrome staining for histopathological changes of lung tissues were observed. Additionally, western blotting and immunohistochemical staining techniques were used to detect expression of transforming growth factor-β1 (TGF-β1), type I collagen (Col-I) and α-smooth muscle actin (α-SMA). Finally, the levels of Col-I and hydroxyproline (HYP) in lung tissues were also utilized. YPF-P alleviated the increase of lung coefficient induced by BLM instillation in pulmonary fibrosis rat, pathologic changes and collagen distribution were obviously ameliorated, while the increase of α-SMA-positive cells and TGF-β1 expression was prevented after YPF-P treatment. Moreover, the contents of HYP and Col-I were decreased in YPF-P group. YPF-P had antifibrotic effect in experiment, which may reduce the synthesis and promote the deposition of Col-I via suppressing the increase of TGF-β1-mediated activation of myofibroblasts. © 2014 Royal Pharmaceutical Society.

  13. Angiotensin-II inhibitor (olmesartan)-induced collagenous sprue with resolution following discontinuation of drug

    OpenAIRE

    Nielsen, Jennifer A; Steephen, Anita; Lewin, Matthew

    2013-01-01

    Collagenous sprue (CS) is a pattern of small-bowel injury characterized histologically by marked villous blunting, intraepithelial lymphocytes, and thickened sub-epithelial collagen table. Clinically, patients present with diarrhea, abdominal pain, malabsorption, and weight loss. Gluten intolerance is the most common cause of villous blunting in the duodenum; however, in a recent case series by the Mayo Clinic, it has been reported that olmesartan can have a similar effect. In this case repor...

  14. Organization of fibrillar collagen in the human and bovine cornea: collagen types V and III.

    Science.gov (United States)

    White, J; Werkmeister, J A; Ramshaw, J A; Birk, D E

    1997-01-01

    The localization and fibrillar organization of collagen types V and III in the human and bovine corneal stromas were studied. In the chicken cornea, type V co-assembles with type I collagen as heterotypic fibrils and this interaction is involved in the regulation of fibril diameter necessary for corneal transparency. To determine whether this is a regulatory mechanism common to the corneas of different species the human and bovine corneal stroma were studied. Collagen type V was found in the epithelium and Bowman's membrane in the untreated adult human and bovine cornea using immunofluorescence microscopy. In the absence of any treatment, there was no type V reactivity within the stroma. However, type V collagen was detected homogeneously throughout the corneal stroma after treatments that partially disrupt fibril structure. The reactivity was strongest in the cornea, weaker in the limbus and weakest in the sclera. Fetal corneas showed similar reactivity for type V collagen, but unlike the adult, the stroma was slightly reactive. Immunoelectron microscopy demonstrated that type V collagen was associated with disrupted, but not with intact, fibrils in both human and bovine corneal stroma. Type III collagen reactivity was not detected in the cornea, but was present subepithelially in the limbus and in the scleral stroma. These data indicate that type V collagen is a component of striated collagen fibrils throughout the human and bovine corneal stromas. The interaction of type I and V collagen as heterotypic fibrils masks the helical epitope recognized by the monoclonal antibody against type V collagen. The heterotypic interactions of collagen type V indicate a role in the regulation of fibril diameter analogous to that described in the avian cornea.

  15. 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 ...

  16. Dietary Salba (Salvia hispanica L) improves the altered metabolic fate of glucose and reduces increased collagen deposition in the heart of insulin-resistant rats.

    Science.gov (United States)

    Creus, Agustina; Benmelej, Adriana; Villafañe, Noelia; Lombardo, Yolanda B

    2017-06-01

    This study reports the effects of dietary Salba (chia) seeds on the mechanisms underlying impaired glucose metabolism in the heart of dyslipemic insulin-resistant rats fed a sucrose-rich diet (SRD). Wistar rats were fed a SRD for 3 months. Afterwards, half the animals continued with the SRD; in the other half's diet chia seeds replaced corn oil (CO) for three months (SRD+chia). In the control group, corn starch replaced sucrose. The replacement of CO by chia seeds in the SRD restored the activities of key enzymes involved in heart glucose metabolism decreasing fatty acid oxidation. Chia seeds normalized insulin stimulated GLUT-4 transporter, the abundance of IRS-1 and pAMPK, changed the profile of fatty acid phospholipids, reduced left-ventricle collagen deposition and normalized hypertension and dyslipidemia. New evidence is provided concerning the effects of dietary chia seeds in improving the altered metabolic fate of glucose in the heart of dyslipemic insulin-resistant rats. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. The versatile subepithelial connective tissue graft: a literature update.

    Science.gov (United States)

    Karthikeyan, B V; Khanna, Divya; Chowdhary, Kamedh Yashawant; Prabhuji, M Lv

    2016-01-01

    Harmony between hard and soft tissue morphologies is essential for form, function, and a good esthetic outlook. Replacement grafts for correction of soft tissue defects around the teeth have become important to periodontal plastic and implant surgical procedures. Among a multitude of surgical techniques and graft materials reported in literature, the subepithelial connective tissue graft (SCTG) has gained wide popularity and acceptance. The purpose of this article is to acquaint clinicians with the current understanding of the versatile SCTG. Key factors associated with graft harvesting as well as applications, limitations, and complications of SCTGs are discussed. This connective tissue has shown excellent short- and long-term stability, is easily available, and is economical to use. The SCTG should be considered as an alternative in all periodontal reconstruction surgeries.

  18. Use of subepithelial conjunctive tissue graft in root covering

    Directory of Open Access Journals (Sweden)

    Denis Clemente Rodrigues

    2010-04-01

    Full Text Available Gingival recession may cause cosmetic changes and root hypersensitivity, which can alter mastication and tooth brushing, and thus contribute to the progression of periodontal disease. Treatment of gingival recessions with subepithelial conjunctive tissue grafting is very predictable due to its bilaminar nature. However, some factors may influence the success of the procedure, among them: selection of the lesion; characteristics of the defect with regard to the depth and width of the recession, the deeper and wider the recession, the worse the prognosis, and also the presence of restorations. Furthermore, it is necessary to control the etiologic factors of recessions, such as inflammation and traumatic brushing, control of systemic factors, occlusal trauma, smoking and harmful habits, technical considerations and asepsis. The success of the procedure must be based on observing the possible factors that might influence their predictability, as well as respecting the basic principles of mucogingival surgery.

  19. Collagen abnormalities in conjunctiva of patients with cicatricial pemphigoid.

    Science.gov (United States)

    Dutt, J E; Ledoux, D; Baer, H; Foster, C S

    1996-11-01

    The purpose of this study was to analyze the distribution and types of collagen in the substantia propria of the conjunctiva of patients with ocular cicatricial pemphigoid (OCP). Biopsy specimens were collected from 10 patients with active OCP, five patients with active Behçet's disease, nine patients with atopic keratoconjunctivitis, five patients with chronic rosacea blepharoconjunctivitis, and six normal patients undergoing cataract surgery. Cryostat tissue sections were cut and stained using an indirect immunofluorescence technique, employing a panel of primary antibodies directed against seven collagen types. Differences between OCP, Behçet's, and normal conjunctiva were seen in the staining for collagen types III, IV, and VII. The intensity of staining for type III collagen was increased in the substantia propria of OCP conjunctiva as compared to the other groups. The basement membrane zone (BMZ) of OCP patients was typically disrupted and fragmented in appearance when stained for type IV collagen, a finding not seen in the non-OCP specimens. The BMZ staining pattern for type VII collagen in OCP conjunctiva was even more disrupted than that seen for type IV collagen, particularly on the posterior side, which was thickened and reduplicated with short fibers extending into the superficial stroma. The production of type III collagen by fibroblasts of the substantia propria is a common feature of diseases associated with subepithelial fibrosis. The damage to the epithelial BMZ and the subsequent attempt at repair with aberrant type IV and VII collagen production are unique to conjunctiva affected by OCP.

  20. Corneal collagens.

    Science.gov (United States)

    Robert, L; Legeais, J M; Robert, A M; Renard, G

    2001-05-01

    Cornea is a highly differentiated tissue rich in extracellular matrix (ECM) specifically distributed in space in order to insure its dual role--transparency and protection of inner eye-tissues. Corneal ECM is especially rich in collagens. Since the characterisation of a number of distinct collagen types it appeared that most of them are present in the cornea. Their synthesis follows a specific program of sequential expression of the different collagen types to be synthesised during the development and maturation of the cornea. The precise regulation of the diameter and orientation of fibers, and of the interfibrillar spaces is partially at least attributed to interactions between glycosaminoglycans and collagens. The 'program' of vectorial collagen synthesis and GAG-collagen interactions changes also with age and in several pathological conditions as corneal dystrophies and wound healing. The Maillard reaction, especially in diabetes, is one of these important factors involved in age-dependent modifications of corneal structure and function. Far from being inert, corneal collagens were shown to have relatively short half-lives. The biosynthesis of corneal collagens was studied also during wound healing. The refibrillation of wounded corneas does not follow the original 'program' of ECM-synthesis as shown by the comparative study of wound healing using biochemical and morphometric methods. This review recapitulates briefly previous and recent studies on corneal collagens in order to present to clinicians and scientists an overview of the state of the art of this important field at the intersection of eye research and matrix biology.

  1. [Relapse of bleeding ulcer in a 15 year-old boy with collagenous gastritis].

    Science.gov (United States)

    Haase, Anne-Mette; Kelsen, Jens

    2012-06-18

    Collagenous gastritis (CG) is a rare disorder. Two patient groups are known: 1) Children and young adults, presenting with anaemia and abdominal pain, and 2) adults presenting with watery diarrhoea. In the latter group, CG is frequently associated with collagenous colitis and/or coeliac disease. This case concerns a 15-year-old boy with a bleeding ulcer. The biopsies from corpus ventriculi showed a thickened subepithelial collagen band (> 10 micrometres), and the patient was diagnosed with CG. Ulcers are rarely linked to CG. CG should be considered when ulcers are found in children and young adults.

  2. Collagen in organ development

    Science.gov (United States)

    Hardman, P.; Spooner, B. S.

    1992-01-01

    It is important to know whether microgravity will adversely affect developmental processes. Collagens are macromolecular structural components of the extracellular matrix (ECM) which may be altered by perturbations in gravity. Interstitial collagens have been shown to be necessary for normal growth and morphogenesis in some embryonic organs, and in the mouse salivary gland, the biosynthetic pattern of these molecules changes during development. Determination of the effects of microgravity on epithelial organ development must be preceded by crucial ground-based studies. These will define control of normal synthesis, secretion, and deposition of ECM macromolecules and the relationship of these processes to morphogenesis.

  3. 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...

  4. Pulmonary expression of interleukin-13 causes inflammation, mucus hypersecretion, subepithelial fibrosis, physiologic abnormalities, and eotaxin production

    Science.gov (United States)

    Zhu, Zhou; Homer, Robert J.; Wang, Zhonde; Chen, Qingsheng; Geba, Gregory P.; Wang, Jingming; Zhang, Yong; Elias, Jack A.

    1999-01-01

    Interleukin (IL)-13 is a pleiotropic cytokine produced in large quantities by activated CD4+ Th2 lymphocytes. To define further its potential in vivo effector functions, the Clara cell 10-kDa protein promoter was used to express IL-13 selectively in the lung, and the phenotype of the resulting transgenic mice was characterized. In contrast to transgene-negative littermates, the lungs of transgene-positive mice contained an inflammatory response around small and large airways and in the surrounding parenchyma. It was mononuclear in nature and contained significant numbers of eosinophils and enlarged and occasionally multinucleated macrophages. Airway epithelial cell hypertrophy, mucus cell metaplasia, the hyperproduction of neutral and acidic mucus, the deposition of Charcot-Leyden–like crystals, and subepithelial airway fibrosis were also prominently noted. Eotaxin protein and mRNA were also present in large quantities in the lungs of the transgene-positive, but not the transgene-negative, mice. IL-4, IL-5, granulocyte-macrophage colony-stimulating factor, and monocyte chemoattractant protein-5 were not similarly detected. Physiological evaluations revealed significant increases in baseline airways resistance and airways hyperresponsiveness (AHR) to methacholine in transgene-positive animals. Thus, the targeted pulmonary expression of IL-13 causes a mononuclear and eosinophilic inflammatory response, mucus cell metaplasia, the deposition of Charcot-Leyden–like crystals, airway fibrosis, eotaxin production, airways obstruction, and nonspecific AHR. IL-13 may play an important role in the pathogenesis of similar responses in asthma or other Th2-polarized tissue responses. PMID:10079098

  5. Conservative treatment of keratoconus by riboflavin-uva-induced cross-linking of corneal collagen: qualitative investigation.

    Science.gov (United States)

    Mazzotta, C; Traversi, C; Baiocchi, S; Sergio, P; Caporossi, T; Caporossi, A

    2006-01-01

    To assess corneal tissue modifications after riboflavin-UVA-induced cross-linking of corneal collagen in patients with progressive keratoconus as well as regeneration of epithelium and subepithelial nerve plexus by in vivo HRT II system confocal microscopy in humans. Ten patients with progressive keratoconus were treated by riboflavin-UVA-induced cross-linking of corneal collagen, involving assessment of ultrastructural modifications of the corneal epithelium and subepithelial nerve plexus by HRT II system confocal microscopy. Treatment included instillation of 0.1% riboflavin-20% dextrane solution 5 minutes before UVA irradiation and every 5 minutes for a total of 30 minutes. Radiant energy was 3 mW/cm 2 or 5.4 Joule/cm 2 and the source was dual UVA (370 nm) light-emitting LED. The protocol included the operation followed by antibiotic medication and eye dressing with a soft therapeutic contact lens. Changes in epithelium and subepithelial and stromal nerve plexus were assessed by HRT II system confocal microscopy in vivo. After 5 days of soft contact lens wearing, corneal epithelium has a regular morphology and density. Disappearance of subepithelial stromal nerve fibers was observed in the central irradiated area where, 1 month after the operation, initial reinnervation was microscopically observed. No changes in nerve fibers were observed in the peripheral untreated with a clear lateral transition between the two areas. Six months after the operation, the anterior subepithelial stroma was recolonized by nerve fibers with restoration of corneal sensitivity. HRT II system confocal microscopy confirms corneal epithelium restore and re-innervation after riboflavin-UVA-induced collagen cross-linking directly in vivo in humans.

  6. A rare case of cystic subepithelial tumor in the stomach: Gastric adenomyoma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ho Seok; Jang, Yun Jin; Heo, Jun [Kyungpook National University Hospital, Daegu (Korea, Republic of)

    2015-12-15

    Gastric adenomyoma is a rare benign subepithelial tumor, characteristically composed of mucosal structures and a prominent smooth muscle stroma. Because of rarity and the nonspecific computed tomography (CT) features, it is difficult to diagnose gastric adenomyoma before operation. In our case, gastric adenomyoma showed a well-circumscribed cystic subepithelial mass with uneven wall thickness on a CT scan, similar to the findings of former reports. The radiologic differential diagnosis can be narrowed down to several diseases, including duplication cysts, gastritis cystica profunda, brunner's gland hyperplasia and solid tumors with cystic degeneration. Also, adenomyoma could be included in the differential diagnosis of gastric cystic subepithelial masses, especially in the distal part of the stomach.

  7. 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.

  8. Immunogold fine structural localization of extracellular matrix components in aged human cornea. I. Types I-IV collagen and laminin.

    Science.gov (United States)

    Marshall, G E; Konstas, A G; Lee, W R

    1991-01-01

    Using the immunogold technique combined with cryoultramicrotomy and London Resin white (LR white) embedding, we studied the fine structural distribution of types I-IV collagen and laminin in corneal tissue from seven enucleated human eyes (age range, 63-78 years). Type II collagen was not identified in any corneal layer. Type I and type III collagen were distributed in a similar fashion in striated collagen fibrils in Bowman's layer and in the stroma. Type IV collagen was located only in the posterior non-banded region of Descemet's membrane. Laminin was identified in subepithelial anchoring plaques and the sub-endothelial region of Descemet's membrane in accordance with its recognized adhesive function.

  9. The Role of Endoscopic Ultrasound in the Diagnostic Assessment of Subepithelial Lesions of the Upper Gastrointestinal Tract

    Directory of Open Access Journals (Sweden)

    Francisca Dias de Castro

    2016-11-01

    Conclusion: EUS is the method of choice in the study of subepithelial lesions of the upper gastrointestinal tract, in most cases defining a diagnosis. The need for a definitive diagnosis or therapeutic approaches can be based on ultrasound risk features, presented, in the majority, at presentation. This study shows that EUS is capable of safely and accurately define those subepithelial lesions that can be managed only with surveillance ultrasound while waiting for better results with fine needle aspiration.

  10. Endoscopic muscularis excavation for subepithelial tumors of the esophagogastric junction originating from the muscularis propria layer.

    Science.gov (United States)

    Zhang, Yu; Ye, Li-ping; Zhu, Lin-hong; Zhou, Xian-bin; Mao, Xin-li; Ding, Jin-xiu

    2013-05-01

    Because of complicating anatomic factors, endoscopic submucosal dissection is seldom performed in subepithelial tumors of the esophagogastric junction originating from the muscularis propria layer. This study was designed to evaluate the feasibility of endoscopic muscularis excavation for treating subepithelial tumors of the esophagogastric junction originating from the muscularis propria layer. Between December 2008 and December 2011, 68 patients with subepithelial tumors of the esophagogastric junction originating from the muscularis propria layer were treated with endoscopic muscularis excavation. Key steps of the procedure included the following: (1) injecting a mixture solution into the submucosal layer after making several dots around the tumor; (2) making a cross incision of the overlying mucosa, and excavating the tumor from the muscularis propria layer; (3) closing the artificial ulcer with clips after tumor removal. The mean tumor size was 16.2 mm (range 7-35 mm). Endoscopic muscularis excavation was successfully performed in 65 out of 68 cases (success rate 95.6 %). Pathological diagnosis of these tumors included leiomyoma (39 out of 68) and gastrointestinal stromal tumor (29 out of 68). Perforation occurred in seven patients (10.3 %). No massive bleeding or delayed bleeding occurred. The median follow-up period after the procedure was 23 months (range 6-42 months). No residual or recurrent tumor was detected and no stricture occurred in patients during the follow-up period. Endoscopic muscularis excavation is a safe, effective and feasible procedure for providing accurate histopathologic evaluation and curative treatment for subepithelial tumors of the esophagogastric junction originating from the muscularis propria layer.

  11. Endoscopic excavation for the treatment of small esophageal subepithelial tumors originating from the muscularis propria.

    Science.gov (United States)

    Ye, Li-ping; Zhu, Lin-hong; Zhou, Xian-bin; Mao, Xin-li; Zhang, Yu

    2015-01-01

    This study was designed to evaluate the safety and efficacy of endoscopic excavation for esophageal subepithelial tumors originating from the muscularis propria. Forty-five patients with esophageal subepithelial tumors originating from the muscularis propria were treated with endoscopic excavation between January 2010 and June 2012. The key steps were: (1) making several dots around the tumor; (2) incising the mucosa along with the marker dots, and then seperating the tumor from the muscularis propria by using a hook knife or an insulated-tip knife; (3) closing the artificial ulcer with clips after the tumor was removed. The mean tumor diameter was 1.1 ± 0.6 cm. Endoscopic excavation was successfully performed in 43 out of 45 cases (95.6%), the other 2 cases were ligated with nylon rope. During the procedure perforation occurred in 4 (8.9%) patients, who recovered after conservative treatment. No massive bleeding or delayed bleeding occurred. Histologic diagnosis was obtained from 43 (95.6%) patients. Pathological diagnoses of these tumors were leiomyomas (38/43) and gastrointestinal stromal tumors (5/43). Endoscopic excavation is a safe and effective method for the treatment of small esophageal subepithelial tumors originating from the muscularis propria.

  12. Increased collagen synthesis rate during wound healing in muscle.

    Directory of Open Access Journals (Sweden)

    Shaobo Zhou

    Full Text Available Wound healing in muscle involves the deposition of collagen, but it is not known whether this is achieved by changes in the synthesis or the degradation of collagen. We have used a reliable flooding dose method to measure collagen synthesis rate in vivo in rat abdominal muscle following a surgical incision. Collagen synthesis rate was increased by 480% and 860% on days 2 and 7 respectively after surgery in the wounded muscle compared with an undamaged area of the same muscle. Collagen content was increased by approximately 100% at both day 2 and day 7. These results demonstrate that collagen deposition during wound healing in muscle is achieved entirely by an increase in the rate of collagen synthesis.

  13. Nitric Oxide and Brazilian Propolis Combined Accelerates Tissue Repair by Modulating Cell Migration, Cytokine Production and Collagen Deposition in Experimental Leishmaniasis

    Science.gov (United States)

    Miranda, Milena Menegazzo; Panis, Carolina; Cataneo, Allan Henrique Depieri; da Silva, Suelen Santos; Kawakami, Natalia Yoshie; Lopes, Luiz Gonzaga de França; Morey, Alexandre Tadachi; Yamauchi, Lucy Megumi; Andrade, Célia Guadalupe Tardelli de Jesus; Cecchini, Rubens; da Silva, Jean Jerley Nogueira; Sforcin, José Maurício; Conchon-Costa, Ivete; Pavanelli, Wander Rogério

    2015-01-01

    The fact that drugs currently used in the treatment of Leishmania are highly toxic and associated with acquired resistance has promoted the search for new therapies for treating American tegumentary leishmaniasis (ATL). In this study, BALB/c mice were injected in the hind paw with Leishmania (Leishmania) amazonensis and subsequently treated with a combination of nitric oxide (NO) donor (cis-[Ru(bpy) 2imN(NO)](PF6)3) (Ru-NO), given by intraperitoneal injection, and oral Brazilian propolis for 30 days. Ru-NO reached the center of the lesion and increased the NO level in the injured hind paw without lesion exacerbation. Histological and immunological parameters of chronic inflammation showed that this combined treatment increased the efficacy of macrophages, determined by the decrease in the number of parasitized cells, leading to reduced expression of proinflammatory and tissue damage markers. In addition, these drugs in combination fostered wound healing, enhanced the number of fibroblasts, pro-healing cytokines and induced collagen synthesis at the lesion site. Overall, our findings suggest that the combination of the NO donor Ru-NO and Brazilian propolis alleviates experimental ATL lesions, highlighting a new therapeutic option that can be considered for further in vivo investigations as a candidate for the treatment of cutaneous leishmaniasis. PMID:25973801

  14. Automated image analysis in the study of collagenous colitis

    Directory of Open Access Journals (Sweden)

    Fiehn AM

    2016-04-01

    Full Text Available Anne-Marie Kanstrup Fiehn,1,2 Martin Kristensson,3 Ulla Engel,4 Lars Kristian Munck,5,6 Susanne Holck,4 Peter Johan Heiberg Engel1,6 1Department of Pathology, Roskilde Hospital, Roskilde, 2Department of Pathology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, 3Digital Pathology, Visiopharm, Hørsholm, 4Department of Pathology, Copenhagen University Hospital, Hvidovre, 5Department of Gastroenterology, Koege Hospital, Koege, 6Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Purpose: The aim of this study was to develop an automated image analysis software to measure the thickness of the subepithelial collagenous band in colon biopsies with collagenous colitis (CC and incomplete CC (CCi. The software measures the thickness of the collagenous band on microscopic slides stained with Van Gieson (VG. Patients and methods: A training set consisting of ten biopsies diagnosed as CC, CCi, and normal colon mucosa was used to develop the automated image analysis (VG app to match the assessment by a pathologist. The study set consisted of biopsies from 75 patients. Twenty-five cases were primarily diagnosed as CC, 25 as CCi, and 25 as normal or near-normal colonic mucosa. Four pathologists individually reassessed the biopsies and categorized all into one of the abovementioned three categories. The result of the VG app was correlated with the diagnosis provided by the four pathologists. Results: The interobserver agreement for each pair of pathologists ranged from Κ-values of 0.56–0.81, while the Κ-value for the VG app vs each of the pathologists varied from 0.63 to 0.79. The overall agreement between the four pathologists was Κ=0.69, while the overall agreement between the four pathologists and the VG app was Κ=0.71. Conclusion: In conclusion, the Visiopharm VG app is able to measure the thickness of a subepithelial collagenous band in colon biopsies with an accuracy comparable to the performance of

  15. Circulating antibodies to α-enolase and phospholipase A2 receptor and composition of glomerular deposits in Japanese patients with primary or secondary membranous nephropathy.

    Science.gov (United States)

    Kimura, Yukihiro; Miura, Naoto; Debiec, Hanna; Morita, Hiroyuki; Yamada, Harutaka; Banno, Shogo; Ronco, Pierre; Imai, Hirokazu

    2017-02-01

    Phospholipase A2 receptor (PLA2R) is recognized as a target antigen in primary membranous nephropathy (MN); Anti-α-enolase antibody in primary and secondary MN has been proposed, however, little is known about the potential contribution of α-enolase to the pathogenesis of MN. We evaluated circulating antibodies to α-enolase by a dot blotting system and PLA2R by indirect immunofluorescence, and glomerular deposition of these proteins in 25 patients with primary MN, 20 patients with secondary MN, 44 patients with collagen disease or severe infection, 60 patients with nephritis (each ten patients of IgA nephropathy, focal segmental gloemrulosclerosis, minimal change nephrotic syndrome, membranoproliferative glomeurlonephritis, diabetic glomerulosclerosis, and tubulointerstitial nephritis) as disease control, and 20 healthy subjects. In primary MN, 18 of 25 sera (72 %) showed anti-α-enolase antibody (IgG1 and IgG4, 11 pts; IgG4 alone, six pts; IgG1 alone, one pt). In secondary MN, 15 of 20 sera (75 %) contained anti-α-enolase antibody (IgG1 and IgG3, 13 pts; IgG3 alone, two pts). No circulating anti-α-enolase antibody was found in 44 collagen diseases or septic patients, 60 nephritis without MN, and 20 healthy subjects. Twelve of 25 sera (48 %) from patients with primary MN were positive for anti-PLA2R antibody, whereas all patients with secondary MN were negative. Eight of the 12 PLA2R-positive patients (67 %) with primary MN also had anti α-enolase antibody. Although PLA2R antigen was present in a subepithelial pattern in 10 of 19 (52 %) patients with primary MN, α-enolase was never detected in glomerular deposits in 19 and ten patients with primary and secondary MN, respectively. Circulating anti-α-enolase antibodies are highly present in both primary and secondary MN (about 70 %, respectively), while anti-PLA2R antibodies are specific for primary MN (48 %) with a prevalence apparently lower in the Japanese population than in Chinese and Caucasian

  16. Angiotensin-II inhibitor (olmesartan)-induced collagenous sprue with resolution following discontinuation of drug

    Science.gov (United States)

    Nielsen, Jennifer A; Steephen, Anita; Lewin, Matthew

    2013-01-01

    Collagenous sprue (CS) is a pattern of small-bowel injury characterized histologically by marked villous blunting, intraepithelial lymphocytes, and thickened sub-epithelial collagen table. Clinically, patients present with diarrhea, abdominal pain, malabsorption, and weight loss. Gluten intolerance is the most common cause of villous blunting in the duodenum; however, in a recent case series by the Mayo Clinic, it has been reported that olmesartan can have a similar effect. In this case report, a 62-year-old female with a history of hypothyroidism and hypertension managed for several years with olmesartan presented with abdominal pain, weight loss, and nausea. Despite compliance to a gluten-free diet, the patient’s symptoms worsened, losing 20 pounds in 3 wk. Endoscopy showed thickening, scalloping, and mosaiform changes of the duodenal mucosa. The biopsy showed CS characterized by complete villous atrophy, lymphocytosis, and thickened sub-epithelial collagen table. After 2 mo cessation of olmesartan, the patient’s symptoms improved, and follow-up endoscopy was normal with complete villous regeneration. These findings suggest that olmesartan was a contributing factor in the etiology of this patient’s CS. Clinicians should be aware of the possibility of drug-induced CS and potential reversibility after discontinuation of medication. PMID:24187471

  17. Angiotensin-II inhibitor (olmesartan)-induced collagenous sprue with resolution following discontinuation of drug.

    Science.gov (United States)

    Nielsen, Jennifer A; Steephen, Anita; Lewin, Matthew

    2013-10-28

    Collagenous sprue (CS) is a pattern of small-bowel injury characterized histologically by marked villous blunting, intraepithelial lymphocytes, and thickened sub-epithelial collagen table. Clinically, patients present with diarrhea, abdominal pain, malabsorption, and weight loss. Gluten intolerance is the most common cause of villous blunting in the duodenum; however, in a recent case series by the Mayo Clinic, it has been reported that olmesartan can have a similar effect. In this case report, a 62-year-old female with a history of hypothyroidism and hypertension managed for several years with olmesartan presented with abdominal pain, weight loss, and nausea. Despite compliance to a gluten-free diet, the patient's symptoms worsened, losing 20 pounds in 3 wk. Endoscopy showed thickening, scalloping, and mosaiform changes of the duodenal mucosa. The biopsy showed CS characterized by complete villous atrophy, lymphocytosis, and thickened sub-epithelial collagen table. After 2 mo cessation of olmesartan, the patient's symptoms improved, and follow-up endoscopy was normal with complete villous regeneration. These findings suggest that olmesartan was a contributing factor in the etiology of this patient's CS. Clinicians should be aware of the possibility of drug-induced CS and potential reversibility after discontinuation of medication.

  18. Is Sub-Epithelial Connective Tissue Graft Really a Gold Standard for the Treatment of Gingival Recession Defects?

    Directory of Open Access Journals (Sweden)

    Ajay Mahajan

    2011-04-01

    Full Text Available Gingival recession defects are one of the most common peri-odontal problems. In the past few decades there have been several attempts to treat the gingival recession defects. Among all the treatment options the sub-epithelial connective tis-sue graft is still the most widely used. The sub-epithelial connective tissue graft is considered to produce high percentage of root coverage and therefore considered to be the gold standard technique for the treatment of gingival reces-sion defects. Despite many research papers favoring the use of sub-epithelial connective tissue graft, recent data suggests no major difference in terms of percent root coverage when various other techniques for the treatment of gingival recession defects are compared with each other. In the light of present clinical evidence the criteria to determine whether sub-epithelial connective tissue graft technique should be considered a gold standard or not for be treatment of gingival recession must be re-evaluated. This article highlights some inherent drawbacks associated with sub-epithelial connective tissue graft and emphasizes the need to consider other available techniques for the treatment of gingival recession defects.

  19. GLP-2 stimulates colonic growth via KGF, released by subepithelial myofibroblasts with GLP-2 receptors

    DEFF Research Database (Denmark)

    Ørskov, Cathrine; Hartmann, Bolette; Poulsen, Steen Seier

    2005-01-01

    in rat, mouse, marmoset and human small and large intestine by immunohistochemistry and in situ hybridisation. By double labelling we found that these GLP-2 receptor immunoreactive cells also produce smooth muscle actin and keratinocyte growth factor (KGF). By subcutaneous infusion of either GLP-2 alone......, GLP-2 plus KGF antibody, KGF antibody alone or saline in mice, we found that KGF antibody abolished the growth promoting effect of GLP-2 in the large intestine, but not in the small intestine. CONCLUSIONS: Our findings suggest that GLP-2 in the gut acts by activating receptors on the subepithelial...... myofibroblasts, causing the release of growth factors, which in turn stimulate intestinal growth....

  20. Elastin development-associated extracellular matrix constituents of subepithelial connective tissue in human pterygium.

    Science.gov (United States)

    Pérez-Rico, Consuelo; Pascual, Gemma; Sotomayor, Sandra; Asúnsolo, Ángel; Cifuentes, Alberto; García-Honduvilla, Natalio; Buján, Julia

    2014-09-02

    We evaluated the expression of several extracellular matrix constituents implicated in the synthesis and reticulation of elastin in human pterygium, according to age and sex of the patients. Pterygia and normal conjunctiva samples were divided into groups according to age (extracellular matrix constituents, LOXs, FBN1, and FBLN5, implicated in the development of elastin, are overexpressed in the subepithelial connective tissue extracellular matrix of human pterygium, supporting our hypothesis that elastic synthesis and reticulation is dysregulated in this type of pathology. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  1. Collagen vascular disease

    Science.gov (United States)

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

  2. Validation of new AJCC exclusion criteria for subepithelial prostatic stromal invasion from pT4a bladder urothelial carcinoma.

    Science.gov (United States)

    Patel, Amit R; Cohn, Joshua A; Abd El Latif, Ahmed; Miocinovic, Ranko; Steinberg, Gary D; Paner, Gladell P; Hansel, Donna E

    2013-01-01

    In 2010 the AJCC (American Joint Committee on Cancer) excluded urothelial carcinoma with subepithelial prostatic stromal invasion from the pT4a bladder cancer staging class, which is otherwise defined by direct prostatic invasion transmurally from the bladder. We determined if the new guidelines were reflective of differences in survival between subepithelial prostatic stromal invasion and transmural pT4a disease. A retrospective, multi-institutional cohort of cystectomy cases with subepithelial prostatic stromal invasion from the University of Chicago and Cleveland Clinic were compared to a cohort with transmural pT4a disease. All pathological specimens were rereviewed at the respective institutions. Patients were excluded from the final cohort if variant bladder cancer histology, pT3 bladder disease or extraprostatic extension of urothelial carcinoma were identified. The primary end points were cancer specific and overall survival. Our study sample consisted of 48 patients with subepithelial prostatic stromal invasion and 49 patients with transmural pT4a disease. Median followup was 12.8 months (IQR 4.9 to 31.4). Patients with subepithelial prostatic stromal invasion had lower rates of lymph node involvement than those with transmural pT4a disease (14.6% vs 61.2%, p transmural pT4a groups, overall survival was 64.0 vs 9.8 months and median cancer specific survival was not achieved vs 16.5 months, respectively (p transmural pT4a disease. Our results support the exclusion of subepithelial prostatic stromal invasion from the pT4a bladder urothelial carcinoma staging class. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  3. Collagen based barrier membranes for periodontal guided bone regeneration applications.

    Science.gov (United States)

    Sheikh, Zeeshan; Qureshi, Javairia; Alshahrani, Abdullah M; Nassar, Heba; Ikeda, Yuichi; Glogauer, Michael; Ganss, Bernhard

    2017-01-01

    Certain cell populations within periodontal tissues possess the ability to induce regeneration, provided they have the opportunity to populate the wound or defect. Guided regeneration techniques have been investigated for regenerating periodontal tissues and such therapies usually utilize barrier membranes. Various natural and synthetic barrier membranes have been fabricated and tested to prevent epithelial and connective tissue cells from invading while allowing periodontal cells to selectively migrate into the defect. This paper focuses on the literature relevant to the use and potential of resorbable collagen membranes in GBR procedures, sites of periodontal and intrabony defects, in cases of socket and alveolar ridge preservation and at implant sites. The results of their use in GBR procedures has shown them to be effective and comparable with non-resorbable membranes with regards to clinical attachment gain, probing depth reduction and defect bone filling. They have also shown to prevent epithelial ingrowth into the defect space during the initial wound healing phase postsurgically. Collagen membranes have also been used for root coverage and GBR procedures and have shown good success rates comparable to subepithelial connective tissue grafts and expanded-polytetrafluoroethylene (e-PTFE) membranes. The future for periodontal tissue engineering is very exciting with the use of barrier membranes expected to continue playing a critical role. However, long-term clinical trials are required to further evaluate and confirm the efficacy of the available collagen barrier membranes for periodontal and bone regeneration use.

  4. Piezoelectric Collagen Hydrogels

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Piezoelectric 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 ...

  5. Is Sub-Epithelial Connective Tissue Graft Really a Gold Standard for the Treatment of Gingival Recession Defects?

    OpenAIRE

    Ajay Mahajan; Ashu Bhardwaj; Poonam Mahajan

    2011-01-01

    Gingival recession defects are one of the most common peri-odontal problems. In the past few decades there have been several attempts to treat the gingival recession defects. Among all the treatment options the sub-epithelial connective tis-sue graft is still the most widely used. The sub-epithelial connective tissue graft is considered to produce high percentage of root coverage and therefore considered to be the gold standard technique for the treatment of gingival reces-sion defects. Despi...

  6. Effects of fish collagen peptides on collagen post-translational modifications and mineralization in an osteoblastic cell culture system.

    Science.gov (United States)

    Yamada, Shizuka; Nagaoka, Hideaki; Terajima, Masahiko; Tsuda, Nobuaki; Hayashi, Yoshihiko; Yamauchi, Mitsuo

    2013-01-01

    Collagen is one of the most widely used biomaterials for tissue engineering and regenerative medicine. Fish collagen peptides (FCP) have been used as a dietary supplement, but their effects on the cellular function are still poorly understood. The objective of this study was to investigate the effects of FCP on collagen synthesis, quality and mineralization using an osteoblastic MC3T3-E1 cell culture system. Cells treated with FCP significantly upregulated the gene expression of several collagen modifying enzymes and more collagen was deposited in the cultures. Collagen in the treated group showed a greater extent of lysine hydroxylation, higher levels of hydroxylysine-aldehyde derived cross-links and accelerated cross-link maturation compared with the untreated group. Furthermore, the treated group showed accelerated matrix mineralization. These results indicate that FCP exerts a positive effect on osteoblastic cells in terms of collagen synthesis, quality and mineralization, thereby suggesting the potential utility of FCP for bone tissue engineering.

  7. Innervation of tissue-engineered recombinant human collagen-based corneal substitutes: a comparative in vivo confocal microscopy study.

    Science.gov (United States)

    Lagali, Neil; Griffith, May; Fagerholm, Per; Merrett, Kimberley; Huynh, Melissa; Munger, Rejean

    2008-09-01

    To compare reinnervation in recombinant human collagen-based corneal substitutes with allografts during a 1-year postimplantation follow-up period in pigs. A retrospective comparison to innervation in porcine collagen-based biosynthetic grafts was also performed. Pigs received a corneal allograft or a substitute made of either recombinant human type-I or -III collagen. In vivo confocal microscopic examination of the central cornea of surgical and untouched control eyes before surgery and at 2, 6, and 12 months after surgery was performed to quantify the number, density, and diameter of nerves at various corneal depths. By 12 months after surgery, the number and density of regenerated nerves in the anterior and deep anterior corneal stroma recovered to preoperative and control levels in both types of substitute grafts and in the allografts. In the subepithelial and subbasal regions, however, significantly fewer nerves were detected relative to those in control subjects at 12 months, regardless of graft type (P collagen-based biosynthetic grafts. An absence of thick stromal nerve trunks (diameter, >10 mum) in all grafts, irrespective of material type, indicated that nerve regeneration in grafts was accompanied by persistent morphologic changes. Nerve regeneration in recombinant human collagen-based biosynthetic corneal grafts proceeded similarly to that in allograft tissue, demonstrating the suitability of recombinant human collagen constructs as nerve-friendly corneal substitutes. Furthermore, only minor differences were noted between type-I and -III collagen grafts, indicating an insensitivity of nerve regeneration to initial collagen type.

  8. The role of subepithelial connective tissue graft for reconstruction of interdental papilla: Clinical study.

    Science.gov (United States)

    Sharma, Ena; Sharma, Anuj; Singh, Kamaljit

    2017-12-01

    The ideal goal of periodontal therapy is regeneration of the lost periodontium. However regeneration of the lost interdental papilla has been elusive. Therefore the ability of rebuilding lost papillae in the maxillary segment has become one of the major challenges in periodontal plastic surgery. To evaluate the success and predictability of surgical technique using a sub epithelial connective tissue graft interposed in a coronally displaced flap to reconstruct the lost interdental papillae. The purpose of this study is to evaluate the success and predictability of a surgical technique using a subepithelial connective tissue graft from the palate with coronally displaced flap to regenerate the lost interdental papilla in 11 systemically healthy patients. Post treatment follow up show statistically significant results from baseline to 3months and 6 months. The present study attempted a single surgical procedure to reconstruct the lost interdental papilla using subepithelial connective tissue graft interposed in coronally displaced flap in 11 patients with Tarnow's class-II papillary recessions. At the end of 6 months it was found that the sites demonstrated significantly superior results as determined by percentage of reduction in the area of the black triangle both clinically (60.26%) and on the model (54.29%). Although complete regeneration of interdental papilla was not achieved, the results of this study demonstrate that a predictable and an esthetically pleasing surgical outcome can be achieved in one attempt for class II papillary recessions. Copyright © 2017. Published by Elsevier B.V.

  9. The roles of types XII and XIV collagen in fibrillogenesis and matrix assembly in the developing cornea.

    Science.gov (United States)

    Young, Blanche B; Zhang, Guiyun; Koch, Manuel; Birk, David E

    2002-01-01

    Corneal transparency depends on the architecture of the stromal extracellular matrix, including fibril diameter, packing, and lamellar organization. The roles of collagen types XII and XIV in regulation of corneal fibrillogenesis and development were examined. The temporal and spatial expression patterns were analyzed using semi-quantitative RT-PCR, in situ hybridization, Western analysis, and immunohistochemistry. Expression of types XII and XIV collagens in cornea development demonstrated that type XII collagen mRNA levels are constant throughout development (10D-adult) while type XIV mRNA is highest in early embryonic stages (10D-14D), decreasing significantly by hatching. The spatial expression patterns of types XII and XIV collagens demonstrated a homogeneous signal in the stroma for type XIV collagen, while type XII collagen shows segregation to the sub-epithelial and sub-endothelial stroma during embryonic stages. The type XII collagen in the anterior stroma was an epithelial product during development while fibroblasts contributed in the adult. Type XIV collagen expression was highest early in development and was absent by hatching. Both types XII and type XIV collagen have different isoforms generated by alternative splicing that may alter specific interactions important in fibrillogenesis, fibril-fibril interactions, and higher order matrix assembly. Analysis of these splice variants demonstrated that the long XII mRNA levels were constant throughout development, while the short XII NC3 mRNA levels peaked early (12D) followed by a decrease. Both type XIV collagen NC1 splice variants are highest during early stages (12D-14D) decreasing by 17D of development. These data suggest type XII collagen may have a role in development of stromal architecture and maintenance of fibril organization, while type XIV collagen may have a role in regulation of fibrillogenesis. Copyright 2002 Wiley-Liss, Inc.

  10. Interproximal Papillae Reconstruction around Implant Using Subepithelial Connective Tissue Graft in Maxillary Anterior Region: A Case Series

    Directory of Open Access Journals (Sweden)

    Satish Gupta

    2012-04-01

    Full Text Available Objectives: The present study was undertaken to evaluate the effectiveness of interproximal papillae reconstruction around early loaded single implant using subepithelial connective tissue graft in maxillary anterior region.Material and Methods: Ten systemically healthy patients (mean age = 29.3 [SD 7.9] years in need of dental implants in maxillary anterior region were included in the study. Interproximal papillae reconstruction around single implant using subepithelial connective tissue graft was applied. The donor palatal tissue was harvested by a ‘trap door approach’. Subepithelial connective tissue graft was inserted in the pouch created on mesial and distal site of implant. Clinical and radiographic parameters were recorded around the each implant, including papillary height and papillary gingival contour, at baseline, 3 and 6 months after operation. Results: The mesial papilla height was increased by 1.9 (SD 0.87 mm, P = 0.005 at 3 month and maintained at 1.5 (SD 0.97 mm, P = 0.007 at 6 months. The distal papilla height was increased by 2 (SD 0.66 mm, P = 0.004 at 3 month and maintained at 1.2 (SD 0.78 mm, P = 0.010 at 6 months. Assessment of papilla contour index showed 90% aesthetic success both for mesial and distal papilla at 6 months.Conclusions: It can be concluded that subepithelial connective tissue graft may be used to successfully augment the gingival papillae adjacent to single tooth implant restoration.

  11. Interproximal Papillae Reconstruction around Implant Using Subepithelial Connective Tissue Graft in Maxillary Anterior Region: A Case Series.

    Science.gov (United States)

    Gupta, Satish; Deo, Vikas; Williams, Cecil

    2012-01-01

    The present study was undertaken to evaluate the effectiveness of interproximal papillae reconstruction around early loaded single implant using subepithelial connective tissue graft in maxillary anterior region. Ten systemically healthy patients (mean age = 29.3 [SD 7.9] years) in need of dental implants in maxillary anterior region were included in the study. Interproximal papillae reconstruction around single implant using subepithelial connective tissue graft was applied. The donor palatal tissue was harvested by a "trap door approach". Subepithelial connective tissue graft was inserted in the pouch created on mesial and distal site of implant. Clinical and radiographic parameters were recorded around the each implant, including papillary height and papillary gingival contour, at baseline, 3 and 6 months after operation. The mesial papilla height was increased by 1.9 (SD 0.87) mm, P = 0.005 at 3 month and maintained at 1.5 (SD 0.97) mm, P = 0.007 at 6 months. The distal papilla height was increased by 2 (SD 0.66) mm, P = 0.004 at 3 month and maintained at 1.2 (SD 0.78) mm, P = 0.010 at 6 months. Assessment of papilla contour index showed 90% aesthetic success both for mesial and distal papilla at 6 months. It can be concluded that subepithelial connective tissue graft may be used to successfully augment the gingival papillae adjacent to single tooth implant restoration.

  12. Pseudomembranous collagenous colitis.

    Science.gov (United States)

    Yuan, Shan; Reyes, Victoria; Bronner, Mary P

    2003-10-01

    The classic clinical and histologic features of collagenous colitis are well characterized; however, the acute or neutrophilic inflammatory changes that may accompany this entity are less well established. In this report of 10 patients, we describe the first series of pseudomembranous collagenous colitis. Because superimposed Clostridium difficile infection was only demonstrated in one patient and no other causes of pseudomembranous colitis were evident in the remaining nine patients, we conclude that pseudomembranes are part of the spectrum of collagenous colitis itself. This case series illustrates the importance of searching for collagenous colitis in the evaluation of pseudomembranous colitis. At the same time, superimposed infectious or ischemic etiologies need to be excluded clinically in any patient with superimposed pseudomembranes. The existence of pseudomembranes in collagenous colitis also lends support to the hypothesis that toxin- and/or ischemia-mediated injury may be involved in the pathogenesis of collagenous colitis.

  13. Immunohistochemical localization of collagen types I and II in the developing chick cornea and tibia by electron microscopy.

    Science.gov (United States)

    Hendrix, M J; Hay, E D; von der Mark, K; Linsenmayer, T F

    1982-03-01

    Monoclonal and conventional antibodies against collagen types I and II were used for immunofluorescence and immuno-electron microscopic studies of developing chick corneas (5-day-old embryos to adult) and embryonic limb cartilages. Secondary antibodies were labeled with rhodamine or ferritin. We found that the 5-day primary corneal stroma stains uniformly at the light microscope level with both monoclonal and rabbit antibodies to collagen types I and II. At the electron microscope level, the striated fibrils are stained by these antibodies. After invasion by fibroblasts (7-day-old embryos), type I collagen becomes the predominant collagen within most of the stroma, whereas type II becomes progressively localized in subepithelial (Bowman's membrane) and subendothelial (Descemet's membrane) regions. In the adult the only remaining type II reactivity is in Descemet's membrane. In this structure, both the nodes and strands stain positively for type II. In embryonic cartilage, on other hand, type II collagen is organized as nonstriated fibrils. Thus, during avian corneal development, radical changes occur both in the the types of collagens present and in their distribution. In addition, it seems that the same genetic type of collagen can take several morphologic forms, depending on the environment fibrils as well as in the nodes and strands of Descemet's membrane.

  14. Partial characterization of cell-type X collagen interactions.

    Science.gov (United States)

    Luckman, Steven P; Rees, Elaine; Kwan, Alvin P L

    2003-06-01

    Type X collagen is a short-chain non-fibrillar collagen that is deposited exclusively at sites of new bone formation. Although this collagen has been implicated in chondrocyte hypertrophy and endochondral ossification, its precise function remains unclear. One possible function could be to regulate the processes of chondrocyte hypertrophy through direct cell-type X collagen interactions. Adhesions of embryonic chick chondrocytes, and cell lines with known expression of collagen-binding integrins (MG63 and HOS), were assayed on chick type X collagen substrates, including the native, heat-denatured and pepsin-digested collagen, and the isolated C-terminal non-collagenous (NC1) domain. Type X collagen supported the greatest level of adhesion for all cell types tested. The involvement of the alpha2beta1 integrin in type X collagen-cell interaction was demonstrated by adhesion studies in the presence of Mg(2+) and Ca(2+) ions and integrin-function-blocking antibodies. Cells expressing alpha2beta1 integrin (chick chondrocytes and MG63 cells) also adhered to heat-denatured type X collagen and the isolated NC1 domain; however, removal of the non-collagenous domains by limited pepsinization of type X collagen resulted in very low levels of adhesion. Both focal contacts and actin stress-fibre formation were apparent in cells plated on type X collagen. The presence of alpha2 and beta1 integrin subunits in isolated chondrocytes and epiphyseal cartilage was also confirmed by immunolocalization. Our results demonstrate, for the first time, that type X collagen is capable of interacting directly with chondrocytes and other cells, primarily via alpha2beta1 integrin. These findings are atypical from the fibrillar collagen-cell interactions via collagen binding integrins in that: (1) the triple-helical conformation is not strictly required for cell adhesion; (2) the NC1 domain is also involved in the adhesion of alpha2beta1-expressing cells. These data form the basis for further

  15. Treatment of multiple gingival recessions adopting modified tunnel subepithelial connective tissue graft technique

    Directory of Open Access Journals (Sweden)

    Jagmohan Singh

    2014-01-01

    Full Text Available Gingival recession related to periodontal disease or developmental problems can result in root sensitivity, root caries, and esthetically unacceptable root exposures. In the past, multiple surgical procedures have been proposed to obtain root coverage on exposed buccal root surfaces. There has been great interest in the treatment of gingival recession defects, especially with subepithelial connective-tissue grafting (SCTG. Recent advances have focused on SCTG by the tunnel technique. This article highlights the esthetic results obtained by adopting a modification of the tunnel technique using a single vertical incision along with autologous SCTG in the management of multiple adjacent Miller Class-II gingival recessions. A single vertical incision was used along with tunnel preparation for the facile placement of SCTG into the prepared tunnel. After 6 months of follow-up, the clinical condition was stable with satisfactory root coverage outcome. An excellent esthetical outcome was achieved and the patient was satisfied with the result.

  16. The "washing line" suture technique for securing the Subepithelial Connective Tissue Graft.

    Science.gov (United States)

    McCrea, Shane J J

    2014-07-01

    Following tooth extraction, resorption of the buccal wall of the socket will occur; this will be true for both the maxilla and the mandible. Where the extraction site is surrounded by natural dentition, the loss of the buccal alveolar plate can degrade the visual aesthetics of an implant-supported prosthetic rehabilitation. To aid the harmonization of the hard and soft tissue morphology, both hard and soft tissue augmentation can be carried out either consecutively with an extraction/immediate implant placement or prior to an implant placement in the delayed scenario. The contemporary method of increasing soft tissue volume is to use the Subepithelial Connective Tissue (auto) Graft (the SCTG). The graft requires fixation, otherwise it can be extruded from the recipient site. This article presents a novel suturing technique which can confidently secure the SCTG, thus resisting its dislodgement.

  17. Removal of an amalgam tattoo using a subepithelial connective tissue graft and laser deepithelialization.

    Science.gov (United States)

    Campbell, Casey M; Deas, David E

    2009-05-01

    A 56-year-old female presented for periodontal treatment with a large amalgam tattoo located in alveolar mucosa on the facial aspect of her maxillary central incisors. The lesion had been present for 42 years since having endodontic surgery at teeth #8 and #9 after a traumatic childhood incident. A two-stage surgical approach was used to eliminate the lesion, beginning with a subepithelial connective tissue graft to increase tissue thickness subjacent to the amalgam tattoo. After 6 weeks of healing, the overlying pigmented tissue was removed using laser surgery to expose the underlying grafted connective tissue. After 2 months of healing following laser surgery, the amalgam pigmentation was completely removed, with good color match and an increased width of keratinized tissue at the surgical site. A relatively large amalgam tattoo in the esthetic zone can be adequately removed by a two-stage procedure using grafted palatal connective tissue and laser deepithelialization.

  18. A single-incision technique to harvest subepithelial connective tissue grafts from the palate.

    Science.gov (United States)

    Hürzeler, M B; Weng, D

    1999-06-01

    This article describes a new and simplified surgical approach to harvest subepithelial connective tissue grafts from the palate. For this procedure, only a single incision parallel to the gingival margin is used to access the donor site for graft preparation and harvesting. Grafts of variable size and thickness can be obtained. Since no band of epithelium is removed with the connective tissue graft the palatal donor site can heal with primary intention. No stents or hemostatic agents are necessary to cover the donor area postoperatively, and suturing can be reduced to a minimum. The harvesting technique is illustrated step by step, and the clinical application of connective tissue grafts harvested with the proposed method is demonstrated with the coverage of a gingival recession.

  19. Collagen and gelatin.

    Science.gov (United States)

    Liu, Dasong; Nikoo, Mehdi; Boran, Gökhan; Zhou, Peng; Regenstein, Joe M

    2015-01-01

    Collagen and gelatin have been widely used in the food, pharmaceutical, and cosmetic industries due to their excellent biocompatibility, easy biodegradability, and weak antigenicity. Fish collagen and gelatin are of renewed interest, owing to the safety and religious concerns of their mammalian counterparts. The structure of collagen has been studied using various modern technologies, and interpretation of the raw data should be done with caution. The structure of collagen may vary with sources and seasons, which may affect its applications and optimal extraction conditions. Numerous studies have investigated the bioactivities and biological effects of collagen, gelatin, and their hydrolysis peptides, using both in vitro and in vivo assay models. In addition to their established nutritional value as a protein source, collagen and collagen-derived products may exert various potential biological activities on cells in the extracellular matrix through the corresponding food-derived peptides after ingestion, and this might justify their applications in dietary supplements and pharmaceutical preparations. Moreover, an increasing number of novel applications have been found for collagen and gelatin. Therefore, this review covers the current understanding of the structure, bioactivities, and biological effects of collagen, gelatin, and gelatin hydrolysates as well as their most recent applications.

  20. Collagen markers in peritoneal dialysis patients

    DEFF Research Database (Denmark)

    Graff, J; Joffe, P; Fugleberg, S

    1995-01-01

    (PICP), aminoterminal propeptide of type III procollagen (PIIINP), and carboxyterminal telopeptide of type I collagen (ICTP)] were studied in 19 nondiabetic peritoneal dialysis patients. The absence of correlation between the mass appearance rates of the markers and the duration of dialysis treatment...... as well as the number of peritonitis episodes supports the concept that peritoneal dialysis does not cause persistent changes in the deposition and degradation rates of collagen. A correlation between the D/Pcreatinine 4 hr and the PICP mass appearance rates was found. Since it is unlikely...

  1. Periurethral injection of collagen in the treatment of urinary stress incontinence: ultrasonographic appearance

    Energy Technology Data Exchange (ETDEWEB)

    Leonhardt, C.; Krysl, J.; Arenson, A.M.; Herschorn, S. [Toronto Univ., ON (Canada). Faculty of Medicine

    1995-06-01

    Transvesical and transvaginal ultrasonography (US) was performed 26 times in 23 patients, 3 to 36 months after periurethral injection of collagen to treat symptomatic urinary stress incontinence. The appearance, location and volume of the collagen were recorded. In all the patients the injected collagen had the appearance of a well-circumscribed mass of variable size, located at the bladder base. Transvesical US demonstrated the collagen in only 17 of the patients, and allowed only limited visualization of the collagen in five of these 17 patients. However, transvaginal US demonstrated the collagen in all of them. The collagen collections showed various levels of echogenicity with both techniques. However, in patients with more than one deposit of collagen, the collections had similar echogenicity. The study indicated that US provides a rapid, noninvasive method of assessing collagen after periurethral injection, and that transvaginal US was the best method of visualizing such collections. 10 refs., 5 figs.

  2. A cell culture model using rat coronary artery adventitial fibroblasts to measure collagen production

    OpenAIRE

    Meszaros Gary; Doane Kathleen; Milsted Amy; Jenkins Cathleen; Toot Jonathan; Ely Daniel

    2007-01-01

    Abstract Background We have developed a rat cell model for studying collagen type I production in coronary artery adventitial fibroblasts. Increased deposition of adventitial collagen type I leads to stiffening of the blood vessel, increased blood pressure, arteriosclerosis and coronary heart disease. Although the source and mechanism of collagen deposition is yet unknown, the adventitia appears to play a significant role. To demonstrate the application of our cell model, cultured adventitial...

  3. Secretion of collagen types I and II by epithelial and endothelial cells in the developing chick cornea demonstrated by in situ hybridization and immunohistochemistry.

    Science.gov (United States)

    Hayashi, M; Ninomiya, Y; Hayashi, K; Linsenmayer, T F; Olsen, B R; Trelstad, R L

    1988-05-01

    Cells involved in the synthesis of collagen types I and II in the cornea of developing chick embryos have been studied by using in situ hybridization and immunohistochemistry. Corneas processed for in situ hybridization with the type I and II collagen probes demonstrated specific mRNAs in the epithelium of embryos at stage 18 with an increase at stages between 26 and 31, and then gradual decrease to the background level in the next several days. In the endothelium, a small amount of specific mRNA was recognized through these stages. In the stroma, only sections hybridized with the type I probe demonstrated mRNA in fibroblasts. Immunostaining demonstrated specific collagen types in the stroma at sites which were closely associated with cells containing specific mRNAs. Both collagens type I and II were present beneath the epithelium as narrow bands at stage 18; as the thicker primary stroma at stages 20 and 26; and as subepithelial, subendothelial and stromal staining at stage 31. Thereafter, type I collagen was increased in the stroma but it was also noted in the subepithelial and, to a lesser degree, subendothelial regions, whereas type II collagen was gradually confined to the subendothelial matrix. Electron microscopic examination of sections from 5-day-old (stage-27) embryo corneas using antibodies against the carboxyl propeptides of type I and II procollagens revealed the presence of these procollagens within the cisternae of the endoplasmic reticulum and Golgi vesicles in both epithelial and endothelial cells. In the epithelial cells both the periderm and basal cells contained these procollagens within the cytoplasmic organelles. These results indicate that not only the epithelial cells, but also the endothelial cells secrete collagen types I and II during the formation of the primary corneal stroma and for several days after invasion of fibroblasts.

  4. A histologic evaluation of various stages of palatal healing following subepithelial connective tissue grafting procedures: a comparison of eight cases.

    Science.gov (United States)

    Soileau, Kristi M; Brannon, Robert B

    2006-07-01

    It is often necessary to procure tissue from the same area of the palate in cases where connective autogenous grafting procedures are warranted due to limitations caused by anatomical features. The purpose of this study was to determine whether the length of time between a first procurement and a second would have any bearing on the quality of tissue available for recipient sites. Eight patients requiring more than one grafting procedure underwent surgery at baseline and again at various intervals ranging from 6 weeks to 11 months. Specimens were taken from the palate and evaluated microscopically, and photographs were taken for purposes of visual comparison. The 6.9- to 7.7-week specimens exhibited complete reepithelialization. The lamina propriae were composed of a cellular proliferation of fibroblasts with loosely arranged collagen deposition and an occasional thin vascular channel. However, remodeling of the wound appeared complete in the specimens removed at the 9-week interval and beyond. The lamina propria was, in general, composed of thick, dense, interlacing bundles of collagen. Small-caliber blood vessels were interspersed throughout the fibrous element. Reharvesting of tissue performed earlier than at 9 weeks may result in poorer autogenous graft quality due to indications that remodeling of the connective tissue is still progressing and not as mature as specimens noted at weeks 9 to 47.

  5. Proximal collagenous gastroenteritides:

    DEFF Research Database (Denmark)

    Nielsen, Ole Haagen; Riis, Lene Buhl; Danese, Silvio

    2014-01-01

    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...... of these disorders is presented. The prognosis of both collagenous gastritis and sprue seems not to be as dismal as considered previously. Data point to involvement of immune or autoimmune mechanisms potentially driven by luminal antigens initiating the fibroinflammatory condition. CONCLUSIONS: To reach...

  6. Cyclosporine a 0.05% eye drops for the treatment of subepithelial infiltrates after epidemic keratoconjunctivitis

    Directory of Open Access Journals (Sweden)

    Okumus Seydi

    2012-08-01

    Full Text Available Abstract Background To evaluate the treatment with topical 0.05% cyclosporine A (CsA in patients with subepithelial corneal infiltrates (SEI. Methods We reviewed 16 patients (22 eyes before and after the treatment with 0.05% CsA eye drops. All patients had been treated previously with topical corticosteroids without any improvement and also they had to stop the medication secondary to intraocular pressure elevation. The objective data recorded included best-corrected visual acuity (BCVA, evaluation of corneal subepithelial infiltrate scores (CSIS, intraocular pressure (IOP prior to treatment and the last follow-up visit. Results Six males (37.5% and 10 females (62.5%, mean age of 35.2 ± 16.6 years, were included. The patients’ average topical CsA use duration was 5.1 ± 3.5 months (1 – 13 months. The average follow up time of the patients was 9.2 ± 4.7 months (4 – 22 months. One patient, although he didn’t have a 0 scale of SCIS, did not show up for follow up examinations after six months. The mean BCVA (logarithm of the minimum angle of resolution before and after the treatment were 0.15 ± 0.15 and 0.07 ± 0.07 respectively, CSIS 1.68 ± 0.89 and 0.23 ± 0.53 respectively, IOP 18.50 ± 3.82 and 16.86 ± 2.76 mmHg respectively. There were statistically significant improvements in BCVA (p = 0.002, reduction of CSIS (p = 0.002 and reduction of IOP (p  Conclusions Topical 0.05% CsA is a safe and effective alternative treatment in patients with SEI who do not respond to other treatment modalities or have undesired side effects from topical steroids.

  7. Collagen XII Contributes to Epicardial and Connective Tissues in the Zebrafish Heart during Ontogenesis and Regeneration.

    Science.gov (United States)

    Marro, Jan; Pfefferli, Catherine; de Preux Charles, Anne-Sophie; Bise, Thomas; Jaźwińska, Anna

    2016-01-01

    Zebrafish heart regeneration depends on cardiac cell proliferation, epicardium activation and transient reparative tissue deposition. The contribution and the regulation of specific collagen types during the regenerative process, however, remain poorly characterized. Here, we identified that the non-fibrillar type XII collagen, which serves as a matrix-bridging component, is expressed in the epicardium of the zebrafish heart, and is boosted after cryoinjury-induced ventricular damage. During heart regeneration, an intense deposition of Collagen XII covers the outer epicardial cap and the interstitial reparative tissue. Analysis of the activated epicardium and fibroblast markers revealed a heterogeneous cellular origin of Collagen XII. Interestingly, this matrix-bridging collagen co-localized with fibrillar type I collagen and several glycoproteins in the post-injury zone, suggesting its role in tissue cohesion. Using SB431542, a selective inhibitor of the TGF-β receptor, we showed that while the inhibitor treatment did not affect the expression of collagen 12 and collagen 1a2 in the epicardium, it completely suppressed the induction of both genes in the fibrotic tissue. This suggests that distinct mechanisms might regulate collagen expression in the outer heart layer and the inner injury zone. On the basis of this study, we postulate that the TGF-β signaling pathway induces and coordinates formation of a transient collagenous network that comprises fibril-forming Collagen I and fiber-associated Collagen XII, both of which contribute to the reparative matrix of the regenerating zebrafish heart.

  8. Self assembled silicon nanowire Schottky junction assisted by collagen

    Science.gov (United States)

    Stievenard, Didier; Sahli, Billel; Coffinier, Yannick; Boukherroub, Rabah; Melnyk, Oleg

    2008-03-01

    We present results on self assembled silicon nanowire Schottky junction assisted by collagen fibrous. The collagen is the principle protein of connective human tissues. It presents the double interest to be a low cost biological material with the possibility to be combed as the DNA molecule. First, the collagen was combed on OTS modified surface with gold electrodes. Second, silicon nanowires were grown on silicon substrate by CVD of silane gas (SiH4) at high temperature (500 C) using a vapor-liquid-solid (VLS) process and gold particles as catalysts. In order to increase electrostatic interaction between the collagen and the nanowires, these latters were chemically modified by mercaptopropylmethoxysilane (MPTS), then chemically oxidized. Therefore, the nanowires were transferred from their substrate into water and a drop of it deposited on the surface. Nanowires are only bound to collagen and in particular, in electrode gaps. The formation of spontaneous Schotkty junction is demonstrated by current-voltage characteristics.

  9. Second-harmonic generation imaging of collagen in ancient bone

    Directory of Open Access Journals (Sweden)

    B. Thomas

    2017-12-01

    Full Text Available Second-harmonic generation imaging (SHG captures triple helical collagen molecules near tissue surfaces. Biomedical research routinely utilizes various imaging software packages to quantify SHG signals for collagen content and distribution estimates in modern tissue samples including bone. For the first time using SHG, samples of modern, medieval, and ice age bones were imaged to test the applicability of SHG to ancient bone from a variety of ages, settings, and taxa. Four independent techniques including Raman spectroscopy, FTIR spectroscopy, radiocarbon dating protocols, and mass spectrometry-based protein sequencing, confirm the presence of protein, consistent with the hypothesis that SHG imaging detects ancient bone collagen. These results suggest that future studies have the potential to use SHG imaging to provide new insights into the composition of ancient bone, to characterize ancient bone disorders, to investigate collagen preservation within and between various taxa, and to monitor collagen decay regimes in different depositional environments.

  10. Microbiologic study of soft contact lenses after laser subepithelial keratectomy for myopia.

    Science.gov (United States)

    Hondur, Ahmet; Bilgihan, Kamil; Cirak, Meltem Yalinay; Dogan, Ozgur; Erdinc, Alper; Hasanreisoglu, Berati

    2008-01-01

    To evaluate the extent and agents of bacterial contamination of bandage disposable soft contact lenses after laser subepithelial keratectomy (LASEK) and to correlate the findings with clinical data. Disposable soft contact lenses were collected from 52 eyes of 26 consecutive patients treated with LASEK for myopia. The patients were treated with a fixed combination of tobramycin and diclofenac until epithelial closure. The lenses were removed on the fourth or fifth postoperative day with sterile forceps and immediately placed in sterile tubes containing culture media brain-heart infusion broth. The lenses were evaluated for microbial colonization. Of the 52 contact lenses analyzed, six (11.5%) had positive cultures. However, no clinical finding of infection was noted. Isolated microorganisms were coagulase-negative staphylococci (two lenses), Stenotrophomonas maltophilia (two lenses), Acinetobacter species (one lens), and Aeromonas hydrophila (one lens). Except for one case, the microorganisms were sensitive to the administered antibiotic. The risk of infectious keratitis after LASEK seems to be low. Except for staphylococci, the isolated microorganisms have not been previously reported to colonize the ocular surface or cause keratitis after refractive surgery. These findings may suggest a changing trend of potentially infectious agents after surface ablation.

  11. Use of a subepithelial connective tissue graft to treat an area pigmented with graphite.

    Science.gov (United States)

    Phillips, Gregory E; John, Vanchit

    2005-09-01

    Pigmentations of the oral cavity are commonly noted in clinical practice and may have physiologic, non-physiologic, or pathologic etiologies. The most common non-physiologic localized pigmentation is the amalgam tattoo; another, less common, non-physiologic pigmentation is the graphite tattoo. Graphite tattoos may easily be confused with amalgam tattoos but have only infrequently been reported in the literature. This case report discusses a patient with a localized pigmented lesion involving the free gingiva, attached gingiva, and alveolar mucosa. The patient was referred for esthetic enhancement of the area in question. Dental history revealed trauma to the area involving falling on a pencil as a child. The lesion was excised and submitted for histologic examination; a subepithelial connective tissue graft was harvested and utilized to prevent an esthetic defect. Histologic evaluation confirmed graphite within the soft tissue as the etiology of the discoloration. At the 2-month postoperative appointment, a highly esthetic outcome was obtained utilizing a connective tissue graft. Although less common than the amalgam tattoo, the graphite tattoo may be encountered in the course of routine dental examinations and should be included in a differential diagnosis of any localized pigmented lesion. Although histologic evaluation is necessary to rule out pathology, if the dental history is consistent with the clinical impression of a nonpathologic lesion, such as the graphite tattoo in this case report, treatment with an autogenous connective tissue graft at the time of excision can produce a highly esthetic result and avoid additional surgical procedures in the future.

  12. Patient outcomes following subepithelial connective tissue graft and free gingival graft procedures.

    Science.gov (United States)

    Wessel, Jeffrey R; Tatakis, Dimitris N

    2008-03-01

    Subepithelial connective tissue grafts (CTGs) and free gingival grafts (FGGs) are common periodontal procedures with similar indications; however, they may differ regarding patient outcomes. Reports on postoperative periodontal patient outcomes are limited. The aim of this observational trial was to compare patient-based outcomes for CTGs and FGGs. Patients who received CTG or FGG completed postoperative questionnaires at 3 days and 3 weeks to assess pain, number of analgesic pills taken, and number of days pills were taken. Postoperative pain was assessed using a visual analog scale (VAS). Twenty-three subjects (12 CTGs and 11 FGGs) completed the study. Differences between CTG and FGG groups in VAS pain scores at 3 days did not reach statistical significance. The proportion of subjects reporting pain in the palate at 3 days was significantly greater for FGG (P FGG group, 3-week VAS pain scores were less than the 3-day ones (P FGG is associated with a greater incidence of donor site pain compared to CTG at the early postoperative period. Longer-term pain after soft tissue grafting is associated with greater analgesic usage. There is an opportunity to improve the postoperative protocols of soft tissue grafting, particularly for FGG.

  13. Dimensional changes during early healing after a subepithelial connective tissue graft procedure.

    Science.gov (United States)

    Rotenberg, Shaun A; Tatakis, Dimitris N

    2014-07-01

    The subepithelial connective tissue graft (CTG) is a popular means to treat gingival recession and augment keratinized tissue. Studies exist that examine long-term outcomes of this procedure; however, changes in tissue dimensions during early healing (0 to 21 days postoperatively) are unknown. The aim of this study is to examine bucco-lingual tissue dimension (gingival tissue thickness [GT]) changes during early CTG healing using a non-invasive technique. Thirteen patients who had treatment planned for CTG on a single tooth were recruited for the study. Using a customized acrylic stent, GT was measured preoperatively, at surgery completion, and at 3, 7, 14, and 21 days postoperatively. CTG was performed using an envelope technique. GT changes were analyzed by repeated-measures analysis of variance. All CTG procedures were considered successful with no postoperative complications. GT increased 1.5 mm immediately after surgery (baseline) compared to the preoperative measurement. GT increased on average 96%, 47%, and 2% compared to baseline at days 3, 7, and 14, respectively. Day 3 and day 7 measurements were significantly different from baseline (P tissue dimension. The observed increase in bucco-lingual tissue dimension subsides by the end of the second postoperative week.

  14. Subepithelial connective tissue grafts for the coverage of denuded root surfaces: A clinical report

    Directory of Open Access Journals (Sweden)

    Ahathya R

    2008-01-01

    Full Text Available Aims and Objectives: The aim of this study is to determine the effectiveness of subepithelial connective tissue grafts (SCTG in the coverage of denuded roots. Materials and Methods: A total of 16 sites with ≥2 mm of recession height were included in the study for treatment with SCTG. The clinical parameters, such as recession height, recession width, width of keratinized gingiva, probing pocket depth, and clinical attachment level were measured at the baseline, third month, and at the end of the study [sixth month]. The defects were treated with a coronally positioned pedicle graft combined with connective tissue graft. Results: Out of 16 sites treated with SCTG, 11 sites showed complete (100% root coverage; the mean root coverage obtained was 87.5%. There was a statistically significant reduction in recession height, recession width, and probing pocket depth. There was also a statistically significant increase in the width of keratinized gingiva and also a gain in clinical attachment level. The postoperative results were both clinically and statistically significant ( P 0.05. Conclusion: From this study, it may be concluded that SCTG is a safe and effective method for the coverage of denuded roots.

  15. Evaluation of alteration in mucogingival line location following use of subepithelial connective tissue graft

    Directory of Open Access Journals (Sweden)

    Saber Fariba

    2010-01-01

    Full Text Available Aim and Objective : The aim of this study is to evaluate the positional changes that occur in mucogingival line following the use of subepithelial connective tissue graft (SCTG. Materials and Methods : In 19 Miller class I or II gingival recession defects, distance between mucogingival line (MGL and cemento-enamel junction, also width of keratinized and attached gingiva, and clinical attachment level were measured. SCTG were used for covering the exposed roots. A fore mentioned parameters were repeated at 3, 6 and 12 months after surgery and alterations were measured. Paired t test was used to analyze the results. Results : MGL had been moved in coronal direction (4.39 ± 0.77 mm on average during surgical approach. After 1 year, MGL shifted 2.11 ± 0.7 mm apically. In accordance with this apical shift, a significant increase in the width of keratinized and attached gingival width (2.89 ± 0.63 mm and 2.82 ± 0.5 mm, respectively was seen (P < 0.05. Conclusion : MGL tended to revert back to its original position following the use of SCTG, and this reversion is accompanied with an increase in the keratinized and attached gingival width.

  16. Controlled Palatal Harvest Technique for Harvesting a Palatal Subepithelial Connective Tissue Graft.

    Science.gov (United States)

    Bhatavadekar, Neel B; Gharpure, Amit S

    2018-02-01

    Subepithelial connective tissue grafts (SCTGs) have been extensively used to augment soft-tissue volume on dental implants and natural teeth. The authors present a technique called the controlled palatal harvest (CPH) to obtain SCTGs. CPH provides an alternative to the trap-door and single-incision techniques currently utilized. The objective of this article is to describe this harvesting technique for SCTGs. A case report is presented in which the CPH technique was successfully used to obtain a SCTG. Contrary to current techniques where the SCTG is usually taken from the palatal (bone) side, this technique involves the dissection of a thick split-thickness flap in which the graft is harvested from the raised flap. Further, an L-shaped incision (with an anterior release) improves visibility and dexterity during dissection of the connective tissue graft. This technique enables the operator to maintain a certain minimum overlying flap thickness, and excellent control is ensured over the thickness of the harvested SCTG. The thickness of theremaining connective tissue overlying the palatal can also be controlled by the operator. Thus, the chances of leaving behind a thin tissue covering the palatal bone are reduced, minimizing necrosis and flap sloughing, which further improves grafting success. While the CPH can be used as an alternative to currently employed conventional harvest techniques, it may require greater operator skill. To the best of the authors' knowledge, this is the first report that documents such a technique.

  17. Preoperative predictive factors for gastrointestinal stromal tumors: analysis of 375 surgically resected gastric subepithelial tumors.

    Science.gov (United States)

    Min, Yang Won; Park, Ha Na; Min, Byung-Hoon; Choi, Dongil; Kim, Kyoung-Mee; Kim, Sung

    2015-04-01

    Gastrointestinal stromal tumors (GISTs) and non-GIST subepithelial tumors (SETs) account for about 75 and 25% of gastric hypoechoic SETs ≥2 cm, respectively. Therefore, identifying preoperative predictive factors for GISTs are required to refine surgical indications. We performed a retrospective review of 375 surgically resected gastric hypoechoic SETs ≥2 cm. Demographic data and tumor characteristics based on upper endoscopy and CT findings were compared between GIST and non-GIST SETs originating from muscularis propria layer (leiomyomas, Schwannomas, glomus tumors, and ectopic pancreas). In cardia, leiomyomas were found twice more frequently than GISTs (63.6 versus 31.8%). Perilesional lymph node enlargement (PLNE) was found only in patients with GIST or Schwannomas. Patients with GIST showed a significantly lower rate of PLNE than those with Schwannomas (3.5 versus 29.0%). In multivariate analysis, tumor site outside cardia (odds ratio, 9.157), absence of PLNE (odds ratio, 11.519), old age, large tumor size, exophytic growth pattern, and ulceration or dimpling were identified as independent preoperative predictive factors for GISTs versus non-GIST SETs. The effort for preoperative pathologic diagnosis such as endosonography-guided tissue sampling might be positively considered for SETs at cardia and SETs with PLNE where the possibility of GIST is low.

  18. Porcine collagen matrix for treating gingival recession. Randomized clinical trial.

    Directory of Open Access Journals (Sweden)

    Yuri Castro

    2014-03-01

    Full Text Available Achieving root coverage after exposure caused by gingival recession is one of the main goals of reconstructive periodontal surgery. Even though a large variety of techniques and mucogingival grafting procedures are available, their long-term results are not clear yet. Therefore, this study aimed to compare clinical effectiveness of the porcine collagen matrix with subepithelial connective graft for treating Miller class I and II gingival recessions. Materials and methods: The randomized clinical trial included twelve patients assigned to two groups. In the first group (experimental, six patients were treated using collagen matrix (mean age, 54.3±5.6 years; mean recession 2. 67±1.03mm. Another group (control of six patients was treated using connective grafts (mean age, 57.1± 2.7 years; mean recession 4.33±1.03mm. All patients underwent periodontal evaluation and pre-surgical preparation including oral hygiene instruction and supragingival scaling. Gingival recessions were exposed through partial thickness flaps where the grafts and matrices were placed. Patients were assessed periodically until complete healing of tissue. Results: Root coverage parameters, amount of keratinized gingiva, gingival biotype and clinical attachment level were evaluated. The root coverage percentage for the group using connective graft was 24.7±13.5% and 16.6±26.8% for the one treated with the matrix. The amount of increased keratinized tissue was 4.33±2.06mm and 4.5±0.83mm for the control and experimental group respectively. Both groups increased gingival biotypes from thin to thick at 100%. The final clinical attachment level was 4.17±3.17±04mm for the control group and 0.98mm for the experimental group. There were significant differences between the outcome of gingival recession and clinical attachment. Conclusion: Results indicate both techniques, besides being predictable, are useful for improving clinical parameters when treating gingival recessions

  19. 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...

  20. Deep biopsy via endoscopic submucosal dissection in upper gastrointestinal subepithelial tumors: a prospective study.

    Science.gov (United States)

    Tae, Hye Jin; Lee, Hang Lak; Lee, Kang Nyeong; Jun, Dae Won; Lee, Oh Young; Han, Dong Soo; Yoon, Byung Chul; Choi, Ho Soon; Hahm, Joon Soo

    2014-10-01

    Preoperative pathological diagnosis may improve clinical management decisions in patients with upper gastrointestinal subepithelial tumors (SETs). The aims of this study were to evaluate the diagnostic yield of deep biopsy via an endoscopic submucosal dissection (ESD) technique, the complications associated with the procedure, and the impact on management of patients with upper gastrointestinal SETs. A total of 68 patients with SETs in the stomach or esophagus were voluntarily assigned to two groups. One group underwent endoscopic ultrasound (EUS) and endoscopic deep biopsy using the ESD technique (40 patients), and the other group (28 patients) underwent surgical resection after EUS without obtaining preoperative pathological diagnosis, in accordance with accepted clinical management algorithms. The diagnostic yield of deep biopsy was 90 % (36/40). The results of deep biopsy changed the treatment plans in 14/40 patients (35 %). One patient with lymphoepithelial carcinoma was scheduled for surgical resection, and 13 patients with benign SETs of diameter ≥  2 cm avoided surgery. Of the 28 patients who underwent surgical resection without preoperative pathological diagnosis, 12 (42.9 %) were confirmed to have benign lesions. The mean procedure time for deep biopsy was 13.7 minutes. There were no procedure-related complications in the deep biopsy group.  Deep biopsy by the ESD technique is a safe, high-yield, diagnostic method in patients with upper gastrointestinal SETs. Pathologic confirmation could improve clinical decision making in the management of patients with upper gastrointestinal SETs. NCT 01993199. © Georg Thieme Verlag KG Stuttgart · New York.

  1. Root surface modifiers and subepithelial connective tissue graft for treatment of gingival recessions: a systematic review.

    Science.gov (United States)

    Karam, P S B H; Sant'Ana, A C P; de Rezende, M L R; Greghi, S L A; Damante, C A; Zangrando, M S R

    2016-04-01

    Many techniques and flap designs have been used to treat gingival recession by root coverage, but subepithelial connective tissue graft (SCTG) seems to be the gold standard procedure. In an attempt to improve the healing process and increase the success rate of root coverage, some authors have used root modifiers, including different root conditioners, lasers, EMD, recombinant human growth factors and platelet-rich plasma (PRP). The aim of this systematic review was to evaluate the effects of root biomodification in clinical outcomes of gingival recessions treated with SCTG. Studies reporting SCTG associated with any form of root surface biomodification for root coverage of gingival recessions (Miller Class I and Class II) were considered as eligible for inclusion. Studies needed to have data of clinical outcomes in a follow up of at least 6 months. Screening of the articles, data extraction and quality assessment were conducted independently and in duplicate. None of the products evaluated (citric acid, EDTA, PRP, lasers and EMD) showed evident benefits in clinical outcomes. Test and control groups presented similar outcomes related to root coverage and periodontal parameters, with no statistical differences between them. The exception was root biomodification with the neodymium-doped yttrium aluminium garnet (Nd:YAG) laser, which impaired root coverage and had a detrimental effect on clinical outcomes. Based on the present clinical data, the use of root surface modifiers to improve clinical outcomes in gingival recessions treated with SCTG is not justified. More in vivo studies, and randomized clinical trials with larger sample sizes and extended follow up, are necessary. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Clinical comparision of semilunar coronally positional flap and subepithelial connective tissue graft in root coverage procedure

    Directory of Open Access Journals (Sweden)

    Saave G.

    2009-11-01

    Full Text Available "nBackground and Aim: Several surgical approaches have been used to achieve root coverage. The Subepithelial Connective Tissue Graft (SCTG procedure has been shown to be a predictable means to treat gingival recession. Semilunar Coronally Positioned Flap (SCPF is a simple mucogingival surgery to cover the exposed root surface without harvesting the palatal connective tissue. The purpose of this study is to compare the outcome of gingival recession therapy using SCTG and SCPF. "nMaterials and Methods: Forty Miller class I buccal gingival recessions (≥2mm were selected. Recessions were randomly assigned to receive either the SCPF or SCTG. Recession Height (RH, Recession Width (RW, Width of Keratinized Tissue (WKT, Probing Depth (PD, Clinical Attachment Level (CAL, were measured at baseline, 1, 3, and 6 months after surgery. The data were analyzed using independent t-test and Repeated Measure ANOVA. "nResults: The average percentages of root coverage for SCPF and SCTG were 88% and 71%, respectively; and the complete root coverage observed were 55% and 45%, respectively. There were no significance differences between the two groups with regard to RW, PD, CAL, WKT (except in the third month after surgery which was slightly greater in SCPF group. RH was significantly decreased from 2 to 6 months after surgery in SCPF group. "nConclusion: The findings from this study indicate that if the tissue thickness and initial width of keratinized tissue are sufficient, SCPF may be a good substitute for SCTG in treatment of Miller class I gingival recessions.

  3. Intestinal subepithelial myofibroblasts support the growth of intestinal epithelial stem cells.

    Directory of Open Access Journals (Sweden)

    Nan Ye Lei

    Full Text Available Intestinal epithelial stem cells (ISCs are the focus of recent intense study. Current in vitro models rely on supplementation with the Wnt agonist R-spondin1 to support robust growth, ISC self-renewal, and differentiation. Intestinal subepithelial myofibroblasts (ISEMFs are important supportive cells within the ISC niche. We hypothesized that co-culture with ISEMF enhances the growth of ISCs in vitro and allows for their successful in vivo implantation and engraftment. ISC-containing small intestinal crypts, FACS-sorted single ISCs, and ISEMFs were procured from C57BL/6 mice. Crypts and single ISCs were grown in vitro into enteroids, in the presence or absence of ISEMFs. ISEMFs enhanced the growth of intestinal epithelium in vitro in a proximity-dependent fashion, with co-cultures giving rise to larger enteroids than monocultures. Co-culture of ISCs with supportive ISEMFs relinquished the requirement of exogenous R-spondin1 to sustain long-term growth and differentiation of ISCs. Mono- and co-cultures were implanted subcutaneously in syngeneic mice. Co-culture with ISEMFs proved necessary for successful in vivo engraftment and proliferation of enteroids; implants without ISEMFs did not survive. ISEMF whole transcriptome sequencing and qPCR demonstrated high expression of specific R-spondins, well-described Wnt agonists that supports ISC growth. Specific non-supportive ISEMF populations had reduced expression of R-spondins. The addition of ISEMFs in intestinal epithelial culture therefore recapitulates a critical element of the intestinal stem cell niche and allows for its experimental interrogation and biodesign-driven manipulation.

  4. Age-dependent changes of the immunohistochemical distribution of various collagen types and structural glycoproteins in the human uterine tube.

    Science.gov (United States)

    Schultka, R; Göpel, C; Schuppan, D; Schmidt, T

    1993-12-01

    This immunohistochemical investigation deals with the age-dependent localization and distribution of types I, III, IV, V, and VI collagen and the structural glycoproteins undulin, fibronectin, laminin, tenascin, and vitronectin in the connective tissue of the human uterine tube. The stroma of this oviductal region consisted of all collagen types. Collagen types I and VI were distributed throughout the connective tissue of the mucosa reaching the basal membrane. The findings suggest that the amount of these collagen types and type III collagen increases in relation to age, since the coarser fibres of the mucosal stroma in the uterine tubes of older women were strongly labelled by immunohistochemistry. The pattern of undulin reactivity was similar to that of types I and VI collagen. The exact quantitative proportions of age-related oviductal changes for types I, III, and VI as well as of undulin are still unknown. Type V collagen was associated with a fine fibre meshwork in the mucosal stroma. The fibres reached the subepithelial zone which appeared membrane-like. The location of type V collagen-associated fibres and aldehyde fuchsin-positive fibres characterized in our previous studies appears to be identical. Moreover, the structural glycoproteins undulin, fibronectin, laminin, tenascin, and vitronectin were detected in the mucosal stroma. The staining of fibronectin was less pronounced than that of undulin. Laminin was located in the zone of the basal membrane, whereas tenascin was mainly found in the mucosal vessels. Contrary to these findings, tenascin showed a unique distribution in the region near the basis of the mucosal folds in the isthmic part. Vitronectin could be observed in the same region of the isthmic part of uterine tubes obtained from younger women. However, the zonal localization of vitronectin reactivity was absent in the isthmic part of older women.

  5. The effects of orthodontic movement on a subepithelial connective tissue graft in the treatment of gingival recession.

    Science.gov (United States)

    Tanaka, Orlando Motohiro; Avila, Ana Leticia Rocha; Silva, Gabriela Molina; Añez, Maria Cecilia Galacini; Taffarel, Ivan Pedro

    2010-12-01

    The purpose of this article is to report on the five-year follow-up of a case involving treatment of gingival recession with a subepithelial connective tissue graft prior to orthodontic tooth movement. Gingival recession has a global prevalence that varies from 3 to 100 percent depending on the population studied and the method of analysis. In addition, the frequency of recession seems to be positively correlated with age. Planned orthodontic tooth movement is not necessarily an etiological factor for gingival recession, so long as it does not move the tooth out of its alveolar process. When the tooth is shifted without adequate biomechanical control, bone dehiscence can develop, and the recession can occur as a consequence of the orthodontic treatment. A 19.6-year-old female patient was referred for orthodontic treatment due to severe anterior-inferior dental crowding and a mandibular right lateral incisor in linguoverson and 4.0 mm of gingival recession on the labial surface. Normal gingival architecture was restored with a subepithelial connective tissue graft used to cover the 4.0 mm defect, after which orthodontic treatment repositioned the malposed incisor into its correct occlusal alignment. Individualized torque was applied to the mandibular right central incisor during the orthodontic treatment. The patient was reevaluated five years after completion of the orthodontic treatment. At the five-year recall appointment, the patient exhibited normal tooth alignment and generalized normal gingival architecture; however, 2 mm of gingival recession was noted on the graft site. This case demonstrated that periodontal surgical correction of facial gingival recession with a subepithelial graft may be performed prior to initiating orthodontic treatment.

  6. Surgical treatment of localized gingival recessions using coronally advanced flaps with or without subepithelial connective tissue graft.

    Science.gov (United States)

    Bellver-Fernández, Ricardo; Martínez-Rodriguez, Ana-María; Gioia-Palavecino, Claudio; Caffesse, Raul-Guillermo; Peñarrocha, Miguel

    2016-03-01

    A coronally advanced flap with subepithelial connective tissue graft is the gold standard surgical treatment of gingival recessions, since it offers a higher probability of achieving complete root coverage compared with other techniques. However, optimum short- and middle-term clinical results have also been obtained with coronally advanced flaps alone. The aim of the present study was to evaluate the results obtained by the surgical treatment of localized gingival recessions using coronally advanced flaps with or without subepithelial connective tissue graft. The reduction of recession height was assessed, together with the gain in gingival attachment apical to the recession, and total reduction of recession, in a comparative study of two techniques. Twenty-two gingival recessions were operated upon: 13 in the control group (coronally advanced flap) and 9 in the test group (coronally advanced flap associated to subepithelial connective tissue graft). After 18 months, the mean reduction of recession height was 2.2 ± 0.8 mm in the control group and 2.3 ± 0.7 mm in the test group, with a mean gain in gingival attachment of 1.3 ± 0.9 mm and 2.3 ± 1.3 mm, respectively. In percentage terms, the mean reduction of recession height was 84.6 ± 19.6% in the control group and 81.7 ± 17.8% in the test group, with a mean gain in gingival attachment of 20.5 ± 37.4% and 184.4 ± 135.5%, respectively. Significant reduction of gingival recession was achieved with both techniques, though the mean gain in gingival attachment (in mm and as a %) was greater in test group.

  7. Diagnostic yield and safety of jumbo biopsy forceps in patients with subepithelial lesions of the upper and lower GI tract.

    Science.gov (United States)

    Buscaglia, Jonathan M; Nagula, Satish; Jayaraman, Vijay; Robbins, David H; Vadada, Deepak; Gross, Seth A; DiMaio, Christopher J; Pais, Shireen; Patel, Kal; Sejpal, Divyesh V; Kim, Michelle K

    2012-06-01

    EUS-FNA often fails to make a definitive diagnosis in the evaluation of subepithelial lesions. The addition of jumbo biopsy forceps has the potential to improve diagnostic yield, but published series are limited. To assess the likelihood of definitive diagnosis for subepithelial lesions by using jumbo biopsy forceps during EUS examination. Pooled retrospective analysis. 6 tertiary referral centers. All patients having undergone EUS examination for a subepithelial lesion in which jumbo biopsy forceps were used for tissue acquisition. Diagnostic yield of jumbo biopsy forceps use, complication rates, and comparison of diagnostic yield with that of EUS-FNA. A total of 129 patients underwent EUS with jumbo biopsy forceps; 31 patients (24%) had simultaneous EUS-FNA. The lesion locations were stomach (n = 98), esophagus (n = 14), duodenum (n = 11), colon (n = 5), and jejunum (n = 1). The average lesion size was 14.9 mm ± 9.3 mm. Overall, definitive diagnosis was obtained in 87 of 129 patients (67.4%) by using either method. A definitive diagnosis was provided by jumbo biopsy forceps use in 76 of 129 patients (58.9%) and by FNA in 14 of 31 patients (45.1%) (P = .175). The results in third-layer lesions were definitive with jumbo biopsy forceps in 56 of 86 lesions (65.1%) and with FNA in 6 of 16 lesions (37.5%) (P = .047). For fourth-layer lesions, the results with jumbo biopsy forceps were definitive in 10 of 25 (40.0%) and with FNA in 8 of 14 (57.1%) (P = .330). Forty-five of 129 patients (34.9%) experienced significant bleeding after biopsy with jumbo forceps and required some form of endoscopic hemostasis. Retrospective study. Jumbo forceps are a useful tool for the definitive diagnosis of subepithelial lesions. The greatest benefit appears to be with third-layer (submucosal) lesions. The risk of bleeding is significant. Copyright © 2012 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

  8. Modified Double-Papillae Flap Technique With Subepithelial Connective Tissue Graft for Root Coverage in the Esthetic Zone: Case Report.

    Science.gov (United States)

    Littuma, Gustavo Javier Salazar; Bez, Leonardo; Lopez, Camilo Andres Villabona; Benfatti, Cesar Augusto Magalhães; Magini, Ricardo de Souza

    2017-03-01

    Gingival recession can compromise the esthetic appearance, leading to functional problems, hypersensitivity, and root caries. Several techniques have been implicated for root coverage, which includes pedicle grafts, free gingival grafts, connective tissue grafts, and guided-tissue regeneration. The double-papillae flap associated with subepithelial connective tissue is a predictable technique to cover isolated areas with insufficient attached gingiva apical to a recession. This case report demonstrates a surgical alternative to the technique using a sling periosteal suture to stabilize the connective tissue and pedicle flap during the initial phase of healing, increasing the potential of this periodontal procedure for gingival recession coverage.

  9. 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

  10. Neutrophils drive accelerated tumor progression in the collagen-dense mammary tumor microenvironment

    OpenAIRE

    Garc?a-Mendoza, Mar?a G.; Inman, David R.; Ponik, Suzanne M.; Jeffery, Justin J; Sheerar, Dagna S.; Van Doorn, Rachel R.; Keely, Patricia J.

    2016-01-01

    Background High mammographic density has been correlated with a 4-fold to 6-fold increased risk of developing breast cancer, and is associated with increased stromal deposition of extracellular matrix proteins, including collagen I. The molecular and cellular mechanisms responsible for high breast tissue density are not completely understood. Methods We previously described accelerated tumor formation and metastases in a transgenic mouse model of collagen-dense mammary tumors (type I collagen...

  11. Compression therapy affects collagen type balance in hypertrophic scar.

    Science.gov (United States)

    Tejiram, Shawn; Zhang, Jenny; Travis, Taryn E; Carney, Bonnie C; Alkhalil, Abdulnaser; Moffatt, Lauren T; Johnson, Laura S; Shupp, Jeffrey W

    2016-04-01

    The effects of pressure on hypertrophic scar are poorly understood. Decreased extracellular matrix deposition is hypothesized to contribute to changes observed after pressure therapy. To examine this further, collagen composition was analyzed in a model of pressure therapy in hypertrophic scar. Hypertrophic scars created on red Duroc swine (n = 8) received pressure treatment (pressure device mounting and delivery at 30 mm Hg), sham treatment (device mounting and no delivery), or no treatment for 2 wk. Scars were assessed weekly and biopsied for histology, hydroxyproline quantification, and gene expression analysis. Transcription levels of collagen precursors COL1A2 and COL3A1 were quantified using reverse transcription-polymerase chain reaction. Masson trichrome was used for general collagen quantification, whereas immunofluorescence was used for collagen types I and III specific quantification. Total collagen quantification using hydroxyproline assay showed a 51.9% decrease after pressure initiation. Masson trichrome staining showed less collagen after 1 (P < 0.03) and 2 wk (P < 0.002) of pressure application compared with sham and untreated scars. Collagen 1A2 and 3A1 transcript decreased by 41.9- and 42.3-fold, respectively, compared with uninjured skin after pressure treatment, whereas a 2.3- and 1.3-fold increase was seen in untreated scars. This decrease was seen in immunofluorescence staining for collagen types I (P < 0.001) and III (P < 0.04) compared with pretreated levels. Pressure-treated scars also had lower levels of collagen I and III after pressure treatment (P < 0.05) compared with sham and untreated scars. These results demonstrate the modulation of collagen after pressure therapy and further characterize its role in scar formation and therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. 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...

  13. Collagen markers in peritoneal dialysis patients

    DEFF Research Database (Denmark)

    Graff, J; Joffe, P; Fugleberg, S

    1995-01-01

    Possible relationships between the dialysate-to-plasma creatinine equilibration ratio (D/Pcreatinine 4 hour), duration of peritoneal dialysis treatment, number of peritonitis episodes, and mass appearance rates of three connective tissue markers [carboxyterminal propeptide of type I procollagen...... (PICP), aminoterminal propeptide of type III procollagen (PIIINP), and carboxyterminal telopeptide of type I collagen (ICTP)] were studied in 19 nondiabetic peritoneal dialysis patients. The absence of correlation between the mass appearance rates of the markers and the duration of dialysis treatment...... as well as the number of peritonitis episodes supports the concept that peritoneal dialysis does not cause persistent changes in the deposition and degradation rates of collagen. A correlation between the D/Pcreatinine 4 hr and the PICP mass appearance rates was found. Since it is unlikely...

  14. Bacterial contaminants of bandage contact lenses used after laser subepithelial or photorefractive keratectomy.

    Science.gov (United States)

    Liu, Xiaowei; Wang, Peng; Kao, Andrew A; Jiang, Yang; Li, Ying; Long, Qin

    2012-07-01

    To compare the locations and types of bacterial contamination of bandage disposable soft contact lenses after laser subepithelial keratectomy (LASEK) and photorefractive keratectomy (PRK). Bandage disposable soft contact lenses were collected with sterile forceps from 30 eyes of 15 consecutive patients treated with LASEK (LASEK group) and 30 eyes of 15 consecutive patients who underwent PRK (PRK group) to correct myopia. Immediately after collection, each lens was cut in two parts with sterile scissors and placed onto chocolate agar with one piece outer face down and the inner face down for the other piece. The lenses were analyzed for bacterial colonization and evaluated for the amount of growth on the inner face and outer face, respectively. The antibiotic susceptibility tests were performed for the isolates using disk diffusion. Five positive cultures (16.7%) were found in LASEK group: 4 appeared in the inner face of the lens and1 appeared in the outer face. In PRK group, 2 of the 30 contact lenses (6.67%) had positive cultures; both of them appeared in the outer face of the lens. The difference of positive culture rate in the two groups was not statistically significant (χ=1.46, P=0.228). When comparing the positive colonization rate in location, the positive culture rate in the inner face of LASEK group was statistically significantly higher than that of PRK group (13.3% vs. 0%, χ=4.29, P=0.038); however, no clinical finding of infection was noted. In both groups, methicillin-sensitive coagulase-negative staphylococci (MSSCoN) were the most common isolate. Besides MSSCoN, the growth of methicillin-resistant coagulase-negative staphylococci, Corynebacterium, and Micrococcus were also present in this study. All the microorganisms were sensitive to tobramycin, which was used in conjunction with dexamethasone to treat the cases. Previous literature reports that the risk of infectious keratitis after LASEK or PRK is relatively low. However, within this study, the

  15. Clinical study of two kinds of bandage contact lenses after laser-assisted subepithelial keratectomy

    Directory of Open Access Journals (Sweden)

    Wan-Ting Zhang

    2016-07-01

    Full Text Available AIM: To investigate the clinical safety and effectiveness of the two kind of bandage contact lenses: Senofilcon A(Johnson & Johnson Acuvue Oasysand Balafilcon A(Bausch& Lomb pure visionafter laser-assisted subepithelial keratectomy(LASEK. METHODS: Thirty-eight patients(76 eyeswho had undergone the LASEK were divided into two groups. One group of patients wore Balafilcon A, the other group of patients fitted with Senofilcon A. The lenses were worn continuously for 7d. This was a seven-day experience and the patients scored for the symptom of the eyes(sore eyes, foreign body sensation and tearingon the third day and the seventh day. Both of the two groups of patients taken off the soft contact lens on the seventh day and let their vision and corneal staining checked.RESULTS: The symptoms of eye sore and tearing of the two groups patients were different. The patients who wore the Senofilcon A were better. The pain of eyes were also different at 3 and 7d after surgeries(Z=-4.146, P=0.000; Z=-2.814, P=0.005. The difference on tearing between the two groups at 3 and 7d after surgeries were significant(Z=-2.309, P=0.021; Z=-3.276, P=0.001. There was no difference on sensation of dryness between the two groups at 3 and 7d after surgeries(Z=-0.447, P=0.655; Z=-0.966, P=0.334. After the lenses were taken off, the visual acuity of patients wearing Senofilcon A was better(t=3.800, P=0.001; corneal staining showed limited spots in 1-2 quadrants with significant difference(Z=-2.384,P=0.017. CONCLUSION: The Senofilcon A(Johnson & Johnson Acuvue Oasysand Balafilcon A(Bausch& Lomb pure visionbandage contact lenses are safe and effective after LASEK, and the former is better than the latter in epithelial regeneration.

  16. Image analyses of collagen types and thickness in oral sub mucous fibrosis stained with picrosirius red under polarizing microscope

    Directory of Open Access Journals (Sweden)

    Venkatesh V Kamath

    2013-01-01

    Full Text Available Context: Oral submucous fibrosis (OSF is a potentially malignant oral disorder leading to increased fibrosis in the sub-epithelial layer. The collagen in the condition has been a subject of intense scrutiny in an attempt to understand the pathogenesis of the disease. Aim: The present study aims to quantify and qualify the collagen fibers in different histological grades of OSF using picrosirius red stain under the polarizing microscope. The quantification of the fibrosis was carried out using image analysis software and the fibers were graded according to staining hue and intensity into their respective subtypes. Comparison was done with normal mucosa, scar/keloid tissue samples. Materials and Methods: The present study included OSF (n = 50 of differing histological grades, keloid/scar (n = 4 and normal mucosa (n = 6 as control cases. Histological assessment was performed on hematoxylin and eosin stained sections. Picrosirius red stained slides were observed under a polarizing microscope for assessment of collagen subtypes. Quantification of collagen was done under polarizing microscope and image parameters were analyzed using ProReg® Capture Pro 2.8.8 (Lawrence and Mayo India Pvt Ltd, 2011 image analysis software. Results: The epithelial thickness in OSF, scar and keloid is less than that of normal mucosa and progressive decrease in the epithelial thickness is seen in the successive stages of OSF. The fibrosis increases with increasing grades of OSF, was higher in scar and keloid and was highly statistically significant. Type I collagen was more predominant in all stages of OSF, in normal oral mucosa and scar/keloid tissue samples as compared with type III. Though quantitative analysis of the collagen types I and III is possible, with picrosirius red qualitative analysis is an arduous task. The specificity of detection of collagen subtypes was acceptable with the picrosirius red stain, but the sensitivity left a lot to be desired.

  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....... 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...

  18. A Novel Antifibrotic Mechanism of Nintedanib and Pirfenidone. Inhibition of Collagen Fibril Assembly.

    Science.gov (United States)

    Knüppel, Larissa; Ishikawa, Yoshihiro; Aichler, Michaela; Heinzelmann, Katharina; Hatz, Rudolf; Behr, Jürgen; Walch, Axel; Bächinger, Hans Peter; Eickelberg, Oliver; Staab-Weijnitz, Claudia A

    2017-07-01

    Idiopathic pulmonary fibrosis (IPF) is characterized by excessive deposition of extracellular matrix, in particular, collagens. Two IPF therapeutics, nintedanib and pirfenidone, decelerate lung function decline, but their underlying mechanisms of action are poorly understood. In this study, we sought to analyze their effects on collagen synthesis and maturation at important regulatory levels. Primary human fibroblasts from patients with IPF and healthy donors were treated with nintedanib (0.01-1.0 μM) or pirfenidone (100-1,000 μM) in the absence or presence of transforming growth factor-β1. Effects on collagen, fibronectin, FKBP10, and HSP47 expression, and collagen I and III secretion, were analyzed by quantitative polymerase chain reaction and Western blot. The appearance of collagen fibrils was monitored by scanning electron microscopy, and the kinetics of collagen fibril assembly was assessed using a light-scattering approach. In IPF fibroblasts, nintedanib reduced the expression of collagen I and V, fibronectin, and FKBP10 and attenuated the secretion of collagen I and III. Pirfenidone also down-regulated collagen V but otherwise showed fewer and less pronounced effects. By and large, the effects were similar in donor fibroblasts. For both drugs, electron microscopy of IPF fibroblast cultures revealed fewer and thinner collagen fibrils compared with untreated controls. Finally, both drugs dose-dependently delayed fibril formation of purified collagen I. In summary, both drugs act on important regulatory levels in collagen synthesis and processing. Nintedanib was more effective in down-regulating profibrotic gene expression and collagen secretion. Importantly, both drugs inhibited collagen I fibril formation and caused a reduction in and an altered appearance of collagen fibril bundles, representing a completely novel mechanism of action for both drugs.

  19. 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

  20. The composition of wide-spaced collagen in normal and diseased Descemet's membrane.

    Science.gov (United States)

    Levy, S G; Moss, J; Sawada, H; Dopping-Hepenstal, P J; McCartney, A C

    1996-01-01

    Descemet's membrane, the specialised basement membrane of the corneal endothelium, contains a form of extracellular matrix described as wide-spaced collagen. In healthy human Descemet's membrane, wide-spaced collagen forms a highly ordered array in a region called the anterior banded zone. However, in corneal endotheliopathies such as Fuchs' endothelial dystrophy and the iridocorneal-endothelial syndrome large amounts of wide-spaced collagen are deposited posterior to Descemet's membrane in a grotesque parody of the anterior banded zone termed a posterior collagenous layer. The purpose of this study was to identify the composition of the wide-spaced collagen found in the Descemet's membrane of normal and diseased human corneas. Tissue from three normal human corneas, three from patients with Fuchs' endothelial dystrophy and five from patients with the iridocorneal-endothelial syndrome was prepared for immuno-electron microscopy by freezing or embedding in Lowicryl K4M resin. Immunocytochemistry on ultrathin sections was performed with antibodies to collagen Types I, III, V, VI and VIII, fibronectin, laminin, P component and tenascin. Ultrastructural labelling of the wide-spaced collagen in the anterior banded zone of normal and diseased corneas and also of the wide-spaced collagen in the posterior collagenous layer of all the diseased corneas was demonstrated with antibody to collagen Type VIII. Wide-spaced collagen was not labelled by any of the other antibodies used. Large amounts of Type VIII collagen are present in discrete regions of healthy and diseased Descemet's membrane. The deposition of Type VIII collagen may significantly influence the pathobiology of the corneal endotheliopathies.

  1. Heterogeneity of collagens in rabbit cornea: type VI collagen

    National Research Council Canada - National Science Library

    Cintron, C; Hong, BS

    1988-01-01

    .... These physical characteristics, together with the susceptibility of these polypeptides to collagenase and their amino acid composition, identified the high molecular weight aggregate as type VI collagen...

  2. Topography-guided customized laser-assisted subepithelial keratectomy for the treatment of postkeratoplasty astigmatism.

    Science.gov (United States)

    Rajan, Madhavan S; O'Brart, David P S; Patel, Parul; Falcon, Mike G; Marshall, John

    2006-06-01

    To assess topography-assisted corneal wavefront excimer laser surface ablation for the correction of ametropia and irregular astigmatism after keratoplasty. Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. In this pilot study, 15 patients (16 eyes) who were intolerant of spectacle and contact lens correction due to astigmatic anisometropia after keratoplasty (15 penetrating and 1 lamellar) had topography-assisted customized excimer laser treatments. Corneal topographic data using a Keratron Scout, Placido disk system allowed for preoperative analysis of wavefront anomalies of the anterior corneal surface from which a customized excimer laser correction of both lower-order aberrations (LOAs) and higher-order aberrations (HOAs) was prepared (ORK software) for treatment with a Schwind Esiris flying-spot laser. All eyes had laser-assisted subepithelial keratectomy (LASEK) using 15% alcohol with a 20-second to 30-second application. Four eyes received an application of mitomycin-C (MMC) 0.2 mg/mL for 1 minute after stromal ablation. The mean preoperative spherical equivalent (SE) was -3.50 diopters (D) +/- 3.97 (SD) (range +1.625 to -9.25 D). The preoperative cylindrical error was -7.2 D (range -2.75 to -13.5 D). The programmed laser correction was -3.14 D (range +1.62 to -9 D) with a maximum attempted cylindrical correction of -7 D. Adherent LASEK epithelial flaps along suture lines and the graft-host junction were noted in 9 eyes (56%), although it was possible to obtain and replace a partial flap. A follow-up of 18 months was achieved in all eyes. At the final follow-up visit, the mean postoperative SE was -1.08 +/- 1.85 D (range +3 to -4.78 D) (P<.01, F<.01). Ten eyes (62.5%) were within +/-1 D of the intended correction. The mean postoperative cylindrical error was -2.72 D (range -0.5 to -6.5 D) (P<.001), with vector analysis demonstrating a mean 6.23 D correction. Analysis of HOAs using a 6.0 mm pupil size demonstrated a significant

  3. A cell culture model using rat coronary artery adventitial fibroblasts to measure collagen production

    Directory of Open Access Journals (Sweden)

    Meszaros Gary

    2007-05-01

    Full Text Available Abstract Background We have developed a rat cell model for studying collagen type I production in coronary artery adventitial fibroblasts. Increased deposition of adventitial collagen type I leads to stiffening of the blood vessel, increased blood pressure, arteriosclerosis and coronary heart disease. Although the source and mechanism of collagen deposition is yet unknown, the adventitia appears to play a significant role. To demonstrate the application of our cell model, cultured adventitial fibroblasts were treated with sex hormones and the effect on collagen production measured. Methods Hearts (10–12 weeks were harvested and the left anterior descending coronary artery (LAD was isolated and removed. Tissue explants were cultured and cells (passages 2–4 were confirmed as fibroblasts using immunohistochemistry. Optimal conditions were determined for cell tissue harvest, timing, proliferation and culture conditions. Fibroblasts were exposed to 10-7 M testosterone or 10-7 M estrogen for 24 hours and either immunostained for collagen type I or subjected to ELISA. Results Results showed increased collagen staining in fibroblasts treated with testosterone compared to control and decreased staining with estrogen. ELISA results showed that testosterone increased collagen I by 20% whereas estrogen decreased collagen I by 15%. Conclusion Data demonstrates the usefulness of our cell model in studying the specific role of the adventitia apart from other blood vessel tissue in rat coronary arteries. Results suggest opposite effects of testosterone and estrogen on collagen synthesis in the rat coronary artery adventitial fibroblasts.

  4. Shear stress-induced collagen XII expression is associated with atherogenesis.

    Science.gov (United States)

    Jin, Xin; Iwasa, Satoshi; Okada, Kyoko; Ooi, Akishi; Mitsui, Kazuhiro; Mitsumata, Masako

    2003-08-15

    Fluid shear stress has been shown to modulate various endothelial functions. We selected a shear stress-specific clone, identified as collagen XII, from a bovine aortic endothelial cell (BAEC) cDNA library. We confirmed that shear stress induces collagen XII expression at both the mRNA and protein levels in cultured BAECs and human umbilical vein ECs (HUVECs) by stimulating transcription. When HUVECs were exposed to shear stress, they secreted collagen XII protein and it was deposited underneath them. Strong expression of collagen XII was found in the intima of human aortic wall lacking atherosclerotic lesions, whereas weak expression was seen in the intima of atherosclerotic plagues. Furthermore, the downstream portion of atherosclerotic plaques showed apparently weak collagen XII expression compared with the upstream portion. These results suggest that collagen XII expression induced by fluid shear stress may play a role in stabilizing the vascular structure and preventing the formation of atherosclerotic lesions.

  5. Differential expression of type XIV collagen/undulin by human mammary gland intralobular and interlobular fibroblasts.

    Science.gov (United States)

    Atherton, A J; Warburton, M J; O'Hare, M J; Monaghan, P; Schuppan, D; Gusterson, B A

    1998-03-01

    Immunolocalisation of type XIV collagen/undulin in the human mammary gland revealed greater deposition in the interlobular stroma than in the intralobular stroma. The interlobular stroma is located between the breast lobules and their associated intralobular stroma. Fibroblasts isolated from the interlobular stroma synthesised 3- to 5-fold more type XIV collagen/undulin than intralobular fibroblasts, but synthesised type I and type IV collagens in similar amounts. The differential expression of type XIV collagen/undulin was maintained with passage in culture. The results suggest a role for type XIV collagen/undulin in stabilising dense collagen fibrils. The maintenance of two types of structurally distinct stromas may be important during developmental processes in the mammary gland.

  6. Type I collagen as an extracellular matrix for the in vitro growth of human small intestinal epithelium.

    Directory of Open Access Journals (Sweden)

    Ziyad Jabaji

    Full Text Available We previously reported in vitro maintenance and proliferation of human small intestinal epithelium using Matrigel, a proprietary basement membrane product. There are concerns over the applicability of Matrigel-based methods for future human therapies. We investigated type I collagen as an alternative for the culture of human intestinal epithelial cells.Human small intestine was procured from fresh surgical pathology specimens. Small intestinal crypts were isolated using EDTA chelation. Intestinal subepithelial myofibroblasts were isolated from a pediatric sample and expanded in vitro. After suspension in Matrigel or type I collagen gel, crypts were co-cultured above a confluent layer of myofibroblasts. Crypts were also grown in monoculture with exposure to myofibroblast conditioned media; these were subsequently sub-cultured in vitro and expanded with a 1∶2 split ratio. Cultures were assessed with light microscopy, RT-PCR, histology, and immunohistochemistry.Collagen supported viable human epithelium in vitro for at least one month in primary culture. Sub-cultured epithelium expanded through 12 passages over 60 days. Histologic sections revealed polarized columnar cells, with apical brush borders and basolaterally located nuclei. Collagen-based cultures gave rise to monolayer epithelial sheets at the gel-liquid interface, which were not observed with Matrigel. Immunohistochemical staining identified markers of differentiated intestinal epithelium and myofibroblasts. RT-PCR demonstrated expression of α-smooth muscle actin and vimentin in myofibroblasts and E-Cadherin, CDX2, villin 1, intestinal alkaline phosphatase, chromogranin A, lysozyme, and Lgr5 in epithelial cells. These markers were maintained through several passages.Type I collagen gel supports long-term in vitro maintenance and expansion of fully elaborated human intestinal epithelium. Collagen-based methods yield familiar enteroid structures as well as a new pattern of sheet

  7. Epithelial Inclusions Following a Bilaminar Root Coverage Procedure with a Subepithelial Connective Tissue Graft: A Histologic and Clinical Study.

    Science.gov (United States)

    Romano, Federica; Perotto, Stefano; Cricenti, Luca; Gotti, Stefano; Aimetti, Mario

    The aim of this study was to histologically examine any epithelial cell inclusions in submerged subepithelial connective tissue graft (SCTG) after clinical healing was achieved. A total of 16 patients with Miller Class I or II gingival recessions were consecutively treated with a bilaminar procedure. At 2 months after surgery, a gingival tissue specimen was harvested from all SCTG-treated sites and stained with hematoxylin-eosin. The histologic evaluation revealed connective tissue in active reorganization without epithelial inclusions in 14 of the 16 tissue specimens. In the remaining 2 specimens, epithelial islands were observed deep in the connective tissue. In one case they developed in a solid cystic space, while in the second case they were strictly integrated in the lamina propria. Complete recession coverage was obtained in 14 of the 16 treated defects, with a mean root coverage of 95.1% ± 14.2% at 12 months.

  8. 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...

  9. 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....

  10. Collagen: Benefits in wound Healing

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Collagen: Benefits in wound Healing. As substrate for haemostasis. As chemotactic to cellular elements. As scaffold for transition to mature collagen production & alignment. Resistant to degradation. As template for cellular attachment, migration and proliferation.

  11. Collagen structure regulates fibril mineralization in osteogenesis as revealed by cross-link patterns in calcifying callus

    NARCIS (Netherlands)

    Wassen, M.H.M.; Lammens, J.; Tekoppele, J.M.; Sakkers, R.J.B.; Liu, Z.; Verbout, A.J.; Bank, R.A.

    2000-01-01

    Although >80% of the mineral in mammalian bone is present in the collagen fibrils, limited information is available about factors that determine a proper deposition of mineral. This study investigates whether a specific collagen matrix is required for fibril mineralization. Calcifying callus from

  12. Stability of collagen during denaturation.

    Science.gov (United States)

    Penkova, R; Goshev, I; Gorinstein, S; Nedkov, P

    1999-05-01

    The stability of calf skin collagen (CSC) type I during thermal and chemical denaturation in the presence of glycerol was investigated. Thermal denaturation of type I collagen was performed in the presence of glycerol or in combination with urea and sodium chloride. The denaturation curves obtained in the presence of urea or sodium chloride retained their original shape without glycerol. These curves were shifted upward proportionally to the glycerol concentration in the reaction medium. This means that glycerol and the denaturants act independently. The explanation is based on the difference in the mechanism of their action on the collagen molecule.

  13. Aesthetic management of gingival recession by root biomodification with carbon dioxide laser and subepithelial connective tissue graft with lateral repositioned flap technique

    Science.gov (United States)

    Rastogi, Pavitra Kumar; Lal, Nand; Garg, Nimit; Anand, Vishal; Singhal, Rameshwari

    2012-01-01

    Localised gingival recessions continue to represent an important aesthetic condition requiring treatment in periodontics. Various techniques have been tried to treat exposed root surfaces to improve aesthetics with high percentage of success and minimal discomfort. Root biomodification is done to improve the predictability of these procedures. This clinical report describes periodontal plastic procedure involving subepithelial connective tissue graft with lateral repositioned flap technique and root biomodification with CO2 laser for the management of gingival recession. PMID:22778454

  14. Type-1 Collagen differentially alters [beta]-catenin accumulation in primary Dupuytren's Disease cord and adjacent palmar fascia cells

    National Research Council Canada - National Science Library

    Vi, Linda; Njarlangattil, Anna; Wu, Yan; Gan, Bing Siang; O'Gorman, David B

    2009-01-01

    Dupuytren's Disease (DD) is a debilitating contractile fibrosis of the palmar fascia characterised by excess collagen deposition, contractile myofibroblast development, increased Transforming Growth Factor-[beta] levels and [beta...

  15. Protein release from collagen matrices.

    Science.gov (United States)

    Sano; Hojo; Maeda; Fujioka

    1998-05-04

    The effective delivery of protein drugs is an important research subject in the field of pharmacology, and to prolong the effect of protein drugs, many studies are being conducted to control the release of proteins from various carrier materials. Collagen is one of the most useful candidates for this purpose, and many studies have been reported; pharmaceutical formulations containing collagen in gel, film and sponge form are used to incorporate low-molecular-weight compounds such as antibiotics and carcinostatics, and the release of these compounds is controlled by the concentration of the gel as well as the shape and degree of crosslinking of the matrix. However, it is still difficult to retain protein drugs in the collagen. In this article, we report on the controlled release of protein drugs using collagen which exhibits good biocompatibility as a carrier, focusing on a new drug delivery system, the Minipellet, which we have developed.

  16. Characterization of fibrillar collagens and extracellular matrix of glandular benign prostatic hyperplasia nodules.

    Directory of Open Access Journals (Sweden)

    Tyler M Bauman

    Full Text Available Recent studies have associated lower urinary tract symptoms (LUTS in men with prostatic fibrosis, but a definitive link between collagen deposition and LUTS has yet to be demonstrated. The objective of this study was to evaluate ECM and collagen content within normal glandular prostate tissue and glandular BPH, and to evaluate the association of clinical parameters of LUTS with collagen content.Fibrillar collagen and ECM content was assessed in normal prostate (48 patients and glandular BPH nodules (24 patients using Masson's trichrome stain and Picrosirius red stain. Second harmonic generation (SHG imaging was used to evaluate collagen content. Additional BPH tissues (n = 47 were stained with Picrosirius red and the association between clinical parameters of BPH/LUTS and collagen content was assessed.ECM was similar in normal prostate and BPH (p = 0.44. Total collagen content between normal prostate and glandular BPH was similar (p = 0.27, but a significant increase in thicker collagen bundles was observed in BPH (p = 0.045. Using SHG imaging, collagen content in BPH (mean intensity = 62.52; SEM = 2.74 was significantly higher than in normal prostate (51.77±3.49; p = 0.02. Total collagen content was not associated with treatment with finasteride (p = 0.47 or α-blockers (p = 0.52, pre-TURP AUA symptom index (p = 0.90, prostate-specific antigen (p = 0.86, post-void residual (PVR; p = 0.32, prostate size (p = 0.21, or post-TURP PVR (p = 0.51. Collagen content was not associated with patient age in patients with BPH, however as men aged normal prostatic tissue had a decreased proportion of thick collagen bundles.The proportion of larger bundles of collagen, but not total collagen, is increased in BPH nodules, suggesting that these large fibers may play a role in BPH/LUTS. Total collagen content is independent of clinical parameters of BPH and LUTS. If fibrosis and overall ECM deposition are

  17. Analysis of human collagen sequences.

    Science.gov (United States)

    Nassa, Manisha; Anand, Pracheta; Jain, Aditi; Chhabra, Aastha; Jaiswal, Astha; Malhotra, Umang; Rani, Vibha

    2012-01-01

    The extracellular matrix is fast emerging as important component mediating cell-cell interactions, along with its established role as a scaffold for cell support. Collagen, being the principal component of extracellular matrix, has been implicated in a number of pathological conditions. However, collagens are complex protein structures belonging to a large family consisting of 28 members in humans; hence, there exists a lack of in depth information about their structural features. Annotating and appreciating the functions of these proteins is possible with the help of the numerous biocomputational tools that are currently available. This study reports a comparative analysis and characterization of the alpha-1 chain of human collagen sequences. Physico-chemical, secondary structural, functional and phylogenetic classification was carried out, based on which, collagens 12, 14 and 20, which belong to the FACIT collagen family, have been identified as potential players in diseased conditions, owing to certain atypical properties such as very high aliphatic index, low percentage of glycine and proline residues and their proximity in evolutionary history. These collagen molecules might be important candidates to be investigated further for their role in skeletal disorders.

  18. Ameloblasts express type I collagen during amelogenesis.

    Science.gov (United States)

    Assaraf-Weill, N; Gasse, B; Silvent, J; Bardet, C; Sire, J Y; Davit-Béal, T

    2014-05-01

    Enamel and enameloid, the highly mineralized tooth-covering tissues in living vertebrates, are different in their matrix composition. Enamel, a unique product of ameloblasts, principally contains enamel matrix proteins (EMPs), while enameloid possesses collagen fibrils and probably receives contributions from both odontoblasts and ameloblasts. Here we focused on type I collagen (COL1A1) and amelogenin (AMEL) gene expression during enameloid and enamel formation throughout ontogeny in the caudate amphibian, Pleurodeles waltl. In this model, pre-metamorphic teeth possess enameloid and enamel, while post-metamorphic teeth possess enamel only. In first-generation teeth, qPCR and in situ hybridization (ISH) on sections revealed that ameloblasts weakly expressed AMEL during late-stage enameloid formation, while expression strongly increased during enamel deposition. Using ISH, we identified COL1A1 transcripts in ameloblasts and odontoblasts during enameloid formation. COL1A1 expression in ameloblasts gradually decreased and was no longer detected after metamorphosis. The transition from enameloid-rich to enamel-rich teeth could be related to a switch in ameloblast activity from COL1A1 to AMEL synthesis. P. waltl therefore appears to be an appropriate animal model for the study of the processes involved during enameloid-to-enamel transition, especially because similar events probably occurred in various lineages during vertebrate evolution.

  19. Oriented Collagen Scaffolds for Tissue Engineering

    OpenAIRE

    Shohta Kodama; Taro Saku; Hiroshi Mikami; Go Kuwahara; Toru Kosaka; Yoshihiro Isobe

    2012-01-01

    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...

  20. A microfabricated, optically accessible device to study the effects of mechanical cues on collagen fiber organization.

    Science.gov (United States)

    Winkler, Moritz; Simon, Melinda G; Vu, Timothy; Gartner, Trevor L; Jester, James V; Lee, Abraham P; Brown, Donald J

    2014-04-01

    As the primary structural protein of our bodies, fibrillar collagen and its organizational patterns determine the biomechanics and shape of tissues. While the molecular assembly of individual fibrils is well understood, the mechanisms determining the arrangement of fibers and thus the shape and form of tissues remain largely unknown. We have developed a cell culture model that successfully recapitulates early tissue development and the de novo deposition of collagen fibers to investigate the role of mechanical cues on collagen fiber alignment. The devices used a thin, collagen-coated deformable PDMS membrane inside a tissue culture well built on microscope-grade coverslips. Deformations and strains in the PDMS membrane were quantified by tracking fluorescent bead displacement and through the use of a COMSOL model. Cyclical strains were applied to serum-cultured rabbit corneal cells at 0.5 Hz for 24-48 h and showed a preferred alignment after 36 h of cyclical loading. Cells cultured with ascorbic acid under methylcellulose serum-free conditions deposited a collagenous matrix that was visible under live second harmonic generation microscopy at week 4. Our microfabricated tissue culture system allows for the controllable application of a wide range of stress profiles to cells, and for the observation and quantification of cells and de novo collagen formation in vitro. Future studies will involve the fabrication of models to study the formation and organization of collagen in ocular diseases.

  1. Granular and lattice deposits in corneal dystrophy caused by R124C mutation of TGFBIp.

    Science.gov (United States)

    Patel, Dhara A; Chang, Shu-Hong; Harocopos, George J; Vora, Smita C; Thang, Diep Huu; Huang, Andrew J W

    2010-11-01

    Both granular and lattice deposits are present in Avellino corneal dystrophy (ACD), primarily associated with the R124H mutation of transforming growth factor-β-induced (TGFBIp). We investigated the presence of these deposits in other TGFBI mutations and the use of Thioflavin-T (ThT), a fluorescent amyloid stain for characterizing corneal amyloid deposits. Surgical corneal specimens of 3 unrelated patients clinically diagnosed with ACD were studied. Corneal sections from normal individuals and patients with prior lattice corneal dystrophy (LCD) were used as controls. Histochemical studies were performed with Congo red and Masson trichrome stains, and fluorescent imaging with scanning laser confocal microscopy was performed for ThT and anti-TGFBIp antibody staining. Clinical and histopathological findings supported the diagnoses of ACD in these 3 cases in whom granular deposits stained with Masson trichrome and lattice deposits stained with ThT and Congo red showed birefringence and dichroism as expected. However, genotyping revealed a heterozygous R124C mutation in each case. In addition to classical stromal deposits, unique subepithelial TGFBIp aggregates, which stain with neither ThT nor trichrome, were observed. In control LCD sections, stromal deposits were stained with ThT but not with trichrome, confirming lack of granular deposits. Our results demonstrate that both granular and lattice corneal deposits can be associated with R124C mutation in addition to the more common R124H mutation. An additional feature of nonhyaline, nonamyloid, TGFBIp subepithelial deposits might substantiate the categorization of such cases as a variant form of ACD. This study further validates ThT staining for detection of amyloid TGFBIp deposits.

  2. Human corneal fibrillogenesis. Collagen V structural analysis and fibrillar assembly by stromal fibroblasts in culture.

    Science.gov (United States)

    Ruggiero, F; Burillon, C; Garrone, R

    1996-08-01

    The stroma of the developing cornea is a highly organized extracellular matrix formed essentially by uniform, small-diameter collagen fibrils with constant interfibrillar spacing. Unlike the fibrillogenesis of chicken cornea, the assembly and maturation of human corneal fibrils have been poorly investigated. In the current study, the authors aimed to ascertain the heterotypic organization (collagens I and V) of the human corneal fibrils at the supramolecular level. To gain more insight into the molecular structure of collagen V, its cellular source, and its role in fibrillogenesis, the authors used cultured human corneal fibroblasts. The structure of human corneal stroma after brief homogenization of the tissue was analyzed by immunogold labeling using specific polyclonal antibodies and rotary shadowing. Biochemical, electron microscopic, and immunolabeling approaches were used to investigate the collagen fibril formation and the extracellular matrix synthesis using human corneal fibroblasts grown in culture as a model system. The authors showed that in human corneal stroma, collagen I is distributed uniformly along the striated fibrils, in contrast to collagen V, which could be identified only at sites at which the fibrils partially were disrupted. Rotary shadowing observations of the homogenate revealed that collagen VI, a major component of the human cornea, was associated closely with the collagen fibril surface. Corneal fibroblasts synthesize and deposit a collagenous matrix with fibrils resembling those of the human cornea in appearance and collagen composition. Biochemical data indicate that a high concentration (20% to 30%) of collagen V is synthesized by stromal fibroblasts and that collagen V molecules are processed similarly to matrix forms in which the extension peptides are retained on the molecules. The heterotypic nature (collagens I and V) of human corneal fibrils was determined. Results indicate that human corneal fibroblasts synthesize the major

  3. The lupus band: do the autoantibodies target collagen VII?

    Science.gov (United States)

    Alahlafi, A M; Wordsworth, P; Wojnarowska, F

    2004-03-01

    Circulating autoantibodies directed against basement membrane zone (BMZ) components from patients with bullous pemphigoid and epidermolysis bullosa acquisita have been used to identify their target antigen in the skin and to confirm pathogenicity. Although the pattern of immunofluorescence in those diseases is similar to the lupus band, little is known about the origin and pathogenesis of the lupus band. Identifying the binding sites of the lupus band could provide a clue to the nature of the autoantigen that stimulates autoantibody formation in the skin of patients with systemic lupus erythematosus (SLE) and might provide valuable insight into the factors that influence the localization and pathogenicity of the lupus band. To investigate the relation between the lupus band and the main BMZ components and to identify the target epitopes of autoantibodies deposited in the skin of patients with SLE. Colocalization of the main components of the skin BMZ in nonlesional SLE skin with the lupus band was investigated using conventional immunofluorescence and confocal laser scanning microscopy. The effect of collagenase and pepsin on the expression of the lupus band was correlated with the differential sensitivity of these proteases on the collagenous and noncollagenous (NC) domains of collagen VII. Reactivity of sera from patients with SLE to a complete recombinant human NC1 domain of type VII collagen was then investigated by enzyme-linked immunosorbent assay (ELISA). Near complete colocalization of the lupus band with collagen VII was found in this study, and chemical degradation of the skin attenuated the expression of the lupus band. Collectively, the NC1 domain of collagen VII was suggested as the target antigen of the lupus band, but none of the sera from patients with SLE reacted with recombinant NC1 domain-coated ELISA plates. Alternative explanations for the results of the colocalization of the lupus band with collagen VII are discussed. The lupus band

  4. Fabrication of Compositionally and Topographically Complex Robust Tissue Forms by 3D-Electrochemical Compaction of Collagen

    Science.gov (United States)

    Younesi, Mousa; Islam, Anowarul; Kishore, Vipuil; Panit, Stefi; Akkus, Ozan

    2015-01-01

    Collagen solutions are phase-transformed to mechanically robust shell structures with curviplanar topographies using electrochemically induced pH gradients. The process enables rapid layer-by-layer deposition of collagen-rich mixtures over the entire field simultaneously to obtain compositionally diverse multilayered structures. In-plane tensile strength and modulus of the electrocompacted collagen sheet samples were 5200 -fold and 2300 -fold greater than that of uncompacted collagen samples. Out of plane compression tests showed 27 -fold and fold increase in compressive stress and 46 -fold increase in compressive modulus compared to uncompacted collagen sheets. Cells proliferated 4.9 times faster, and cellular area spread was 2.7 times greater on compacted collagen sheets. Electrocompaction also resulted in 2.9 times greater focal adhesion area than on regular collagen hydrogel. The reported improvements in the cell-matrix interactions with electrocompaction would serve to expedite the population of electrocompacted collagen scaffolds by cells. The capacity of the method to fabricate nonlinear curved topographies with compositional heterogeneous layers is demonstrated by sequential deposition of collagenhydroxyapatite layer over a collagen layer. The complex curved topography of the nasal structure is replicated by the electrochemical compaction method. The presented electrochemical compaction process is an enabling modality which holds significant promise for reconstruction of a wide spectrum of topographically complex systems such as joint surfaces, craniofacial defects, ears, nose or urogenital forms. PMID:26069162

  5. 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.

  6. Adrenomedullin alleviates pulmonary artery collagen accumulation in rats with pulmonary hypertension induced by high blood flow.

    Science.gov (United States)

    Pang, Lulu; Qi, Jianguang; Gao, Yang; Jin, Hongfang; Du, Junbao

    2014-04-01

    Collagen accumulation is one of the important pathologic changes in the development of pulmonary hypertension. Previous research showed that adrenomedullin (ADM) mitigates the development of pulmonary hypertension. The present study explored the role of ADM in the development of pulmonary artery collagen accumulation induced by high pulmonary blood flow, by investigating the effect of ADM [1.5 μg/(kg h)] subcutaneously administered by mini-osmotic pump on pulmonary hemodynamics, pulmonary vascular structure and pulmonary artery collagen accumulation and synthesis in rats with high pulmonary blood flow induced by aortocaval shunting. The results showed that ADM significantly decreased mean pulmonary artery pressure (mPAP) and the ratio of right ventricular mass to left ventricular plus septal mass [RV/(LV+SP)], attenuated the muscularization of small pulmonary vessels and relative medial thickness (RMT) of pulmonary arteries in rats with high pulmonary blood flow. Meanwhile, ADM ameliorated pulmonary artery collagen deposition represented by a decrease in lung tissue hydroxyproline, collagens I and III content and pulmonary artery collagens I and III expression, reduced collagen synthesis represented by a decrease in lung tissue procollagens I and III mRNA expression. The results suggest that ADM plays a protective role in the development of pulmonary hypertension induced by high blood flow, by inhibiting pulmonary procollagen synthesis and alleviating pulmonary artery collagen accumulation. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Collagen crosslink location: a molecular marker for fibrosis in lungs of rats with experimental silicosis

    Energy Technology Data Exchange (ETDEWEB)

    Gerriets, J.E.; Reiser, K.M.; Last, J.A.

    1986-05-01

    Collagen content is increased in lungs of animals with experimental silicosis. They hypothesize that the collagen deposited in such fibrotic lungs differs structurally from normal lung collagen. Silicotic lung collagen shows an increase in lysine hydroxylation. In addition, the ratio of the difunctional crosslinks DHLNL (dihydroxylysinonorleucine) to HLNL (hydroxylysinonorleucine) is sharply elevated compared to that in control lungs. The peptide ..cap alpha..1(I)CB7 x ..cap alpha..2(I)CB1 crosslinked by HLNL was demonstrated in NaB/sup 3/H/sub 4/-reduced, CNBr-digested collagen from rat tail tendon by peptide purification, followed by periodate oxidation and amino acid analysis. Further structural analysis of this peptide was obtained by digestion of the crosslinked peptide with trypsin and purification of the tryptic peptide containing this crosslink followed by amino acid analysis. They then examined the analogous collagenous peptide in normal and silicotic lungs and analyzed the crosslink it contained. They observed that DHLNL was present at specific sites previously containing HLNL; that is, the collagen in fibrotic lungs is altered at specific sites by post-translational modification of a lysine residue by hydroxylation in a predictable way. They conclude that such unusual hydroxylation of a specific lysine residue in the ..cap alpha..2 chain provides a molecular marker for fibrotic lung collagen.

  8. Effect of Postoperative Diclofenac on Anastomotic Healing, Skin Wounds and Subcutaneous Collagen Accumulation

    DEFF Research Database (Denmark)

    Klein, M; Krarup, Peter-Martin; Kongsbak, Mikkel

    2012-01-01

    diclofenac treatment significantly inhibited collagen deposition in subcutaneous granulation tissue. Anastomotic strength and skin wound strength were not significantly affected. The ePTFE model is suitable for assessing the effect of various drugs on collagen formation and thus on wound healing....... and an expanded polytetrafluoroethylene (ePTFE) tube was placed subcutaneously. Incisional and anastomotic wound breaking strength and hydroxyproline content in the ePTFE tubes were measured 7 days after the operation. Results: We found no significant differences in any of the breaking strength measurements......, but showed a median 38% reduction in hydroxyproline deposition as a result of diclofenac treatment (p = 0.03). In the placebo group, subcutaneous collagen deposition tended to correlate positively with skin incisional but negatively with anastomotic bio-mechanical strength. Conclusion: Postoperative...

  9. Collagen types I, III and IV in the placentome and interplacentomal maternal and fetal tissues in normal cows and in cattle with retention of fetal membranes.

    Science.gov (United States)

    Boos, A; Stelljes, A; Kohtes, J

    2003-01-01

    The increase in uterine mass during pregnancy requires the establishment of sufficient blood supply to and strong supportive elements within the uterus. These needs are correlated with the remodelling and production of ECM materials. Therefore, placentomes and interplacentomal parts of the uterine walls and adherent allantochorion were collected from 45 cows at slaughter. Additional placentomes were obtained from 5 cows at premature cesarean section and at term in 5 cows releasing their fetal membranes in time or in 5 animals with retention of the fetal membranes, i.e. in total 60 pregnancies. Unfixed cryostat sections from 4 animals per month of pregnancy and 5 animals per peripartal group (in total 51 pregnancies) were used to immunolocalize collagen types I, III, and IV by an indirect FITC method. Collagen types I and III co-localize within the uterus. The tensile strength of the pregnant uterus is mainly represented by high contents of collagen type I within the allantochorion and subepithelial endometrial and subserosal meshes. Chorionic villi are fixed within caruncular crypts by two mechanisms: crypt openings are narrow and supplied with thick edges containing collagen types I and III. Collagen type IV contributes to all basement membranes and encloses connective tissue cells within the maternal crypt stroma, the stratum compactum and the perimetrial connective tissue. At term, fetal membranes and placentomes are edematous and at the light-microscopic level no distinct differences are visible between connective tissue fibers of placentomes from animals retaining the fetal membranes and those releasing them in time. In conclusion, collagen types I, III and IV exhibit type- and location-specific distribution patterns within the uterus of the pregnant cow. These may additionally be influenced by the stage of pregnancy, thus reflecting the dynamic processes at the stromal level. Copyright 2003 S. Karger AG, Basel

  10. A case of in vivo iontophoresis-assisted corneal collagen cross-linking for keratoconus: An immunohistochemical study.

    Science.gov (United States)

    Manetti, Mirko; Favuzza, Eleonora; Sgambati, Eleonora; Mencucci, Rita; Marini, Mirca

    2017-04-01

    The standard corneal collagen cross-linking (CXL), that includes the removal of corneal epithelium to permit adequate penetration of riboflavin in the stroma, is an established procedure to halting keratoconus progression. However, as epithelial removal may cause postoperative pain and an increased risk of corneal infection, new therapeutic approaches have been proposed. Iontophoresis is a recently developed non-invasive technique which provides the use of electrical current during CXL to enhance transepithelial penetration of riboflavin into the corneal stroma. Here, we describe for the first time the morphological changes of the corneal stromal compartment in a patient with keratoconus who underwent in vivo iontophoresis-assisted CXL (ionto-CXL) before full-thickness corneal transplantation. Immunohistochemistry for type I collagen and CD34 was performed to investigate the stromal distribution of collagen fibers and keratocytes, respectively. The histology of ionto-CXL-treated keratoconic cornea, collected 6 months after the intervention, was compared with that of healthy corneas and either untreated or standard CXL-treated keratoconic corneas. An attempt to restore a normal stromal architecture was observed in the ionto-CXL-treated cornea compared with untreated keratoconic corneas. In particular, the ionto-CXL-treated cornea showed a parallel distribution of type I collagen fibers, although fiber interweaving appeared less organized than in healthy corneas and standard CXL-treated keratoconic corneas. Moreover, the distribution of CD34-positive keratocytes was improved in keratoconic corneas following ionto-CXL treatment, though a scattered CD34 immunoreactivity was still noticeable in the subepithelial stroma. This study provides histological evidence that ionto-CXL may represent a non-invasive alternative in the management of progressive keratoconus in adults. Copyright © 2017 Elsevier GmbH. All rights reserved.

  11. Oriented Collagen Scaffolds for Tissue Engineering

    Science.gov (United States)

    Isobe, Yoshihiro; Kosaka, Toru; Kuwahara, Go; Mikami, Hiroshi; Saku, Taro; Kodama, Shohta

    2012-01-01

    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. PMID:28817059

  12. 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.

  13. Oriented Collagen Scaffolds for Tissue Engineering.

    Science.gov (United States)

    Isobe, Yoshihiro; Kosaka, Toru; Kuwahara, Go; Mikami, Hiroshi; Saku, Taro; Kodama, Shohta

    2012-03-16

    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.

  14. Laser-assisted subepithelial keratectomy and photorefractive keratectomy for post-penetrating keratoplasty myopia and astigmatism in adults.

    Science.gov (United States)

    Huang, Paul Y C; Huang, Peter T; Astle, William F; Ingram, April D; Hèbert, Ania; Huang, John; Ruddell, Stacy

    2011-02-01

    To evaluate whether laser-assisted subepithelial keratectomy (LASEK) and photorefractive keratectomy (PRK) achieve effective targeted correction and the extent of post-treatment corneal haze after corneal transplantation. Nonhospital surgical facility, Calgary, Alberta, Canada. Evidence-based manuscript. This study evaluated visual acuity, refractive error correction, and potential complications after LASEK or PRK to eliminate refractive error differences after penetrating keratoplasty in adults. A Nidek EC-5000 or Technolas 217 excimer laser was used in all treatments. At last follow-up (mean 20.50 months post laser), the mean spherical equivalent (SE) decreased from -2.71 diopters (D) ± 4.17 (SD) to -0.54 ± 3.28 D in the LASEK group and from -4.87 ± 3.90 D to -1.82 ± 3.34 D in the PRK group. The mean preoperative uncorrected distance visual acuity (UDVA) was 1.63 ± 0.53 and 1.45 ± 0.64, respectively, and the mean postoperative UDVA, 0.83 ± 0.54 and 0.90 ± 0.55, respectively. The improvement in SE and UDVA was statistically significant in both groups (P < .01). The mean haze (0 to 3 scale) at the last follow-up was 0.46 ± 0.708 in the LASEK group and 0.58 ± 0.776 in the PRK group. The UDVA improved and refractive errors were effectively reduced after LASEK or PRK in eyes with previous PKP. There was no significant difference in the change in SE, UDVA, or corrected distance visual acuity between LASEK and PRK. Some patients had evidence of corneal haze, although the difference between the groups was not significant. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  15. A Comparative 6-Month Clinical Study of Acellular Dermal Matrix Allograft and Subepithelial Connective Tissue Graft for Root Coverage

    Directory of Open Access Journals (Sweden)

    S. Sadat Mansouri

    2010-09-01

    Full Text Available Objective: Different surgical procedures have been proposed for the treatment of gingival recessions. The goal of this study was to compare the clinical results of gingival recession treatment using Subepithelial Connective Tissue Graft and an Acellular Dermal MatrixAllograft.Materials and Methods: The present study was performed on 5 patients with 9 bilateral Miller`s class I or II gingival recessions. This included 15 premolars and 3 canines. In each patient the teeth were randomly divided in two groups of test (ADMA and control (SCTG.Clinical parameters including recession height (RH, recession width (RW, keratinized gingiva (KG, clinical attachment level (CAL and probing depth (PD were measured at baseline, 2, 4 and 6 months after surgery and data analysis was performed using the Wilcoxon signed rank test.Results: The mean changes (mm from baseline to 6 months in SCTG and ADMA were 2.22±0.83 and 1.77±0.66 decrease in RH, 2.55±0.88 and 2.33±0.86 decrease in RW,1.44±0.88 and 2.0±1.11 increase in KG, 2.33±1.22 and 2.11±0.6 decrease in CAL and finally 0.22±0.66 and 0.33±0.7 decrease in PD, respectively. The differences in meanchanges were not significant between the two groups in any of the parameters. The percentage of root coverage was 85.7% and 71.1% for the control and test group,respectively. The changes from baseline to the 6 month visit were significant for both groups in all parameters but PD.Conclusion: Alloderm may be suggested as an acceptable substitute for connective tissue graft considering the root coverage effect and KG width increase.

  16. Sub-epithelial connective tissue graft for root coverage in nonsmokers and smokers: A pilot comparative clinical study

    Directory of Open Access Journals (Sweden)

    Chini Doraswamy Dwarakanath

    2016-01-01

    Full Text Available Background: Gingival recession is a common condition and is more prevalent in smokers. It is widely believed that root coverage procedures in smokers result in less desirable outcome compared to nonsmokers', and there are few controlled studies in literature to support this finding. Therefore, the purpose of this study was to evaluate and compare the outcome of root coverage with sub-epithelial connective tissue graft (SCTG in nonsmokers and smokers. Materials and Methods: A sample of twenty subjects, 10 nonsmokers and 10 smokers were selected each with at least 1 Miller's Class I or II recession on a single rooted tooth. Clinical measurements of probing depth, clinical attachment level (CAL, gingival recession total surface area (GRTSA, depth of recession (RD, width of recession (RW, and width of keratinized tissue were determined at baseline, 3, and 6 months after surgery. Results: The treatment of gingival recession with SCTG and coronally advanced flap showed a decrease in the GRTSA, RD, RW, and an increase in CAL and width of keratinized gingiva in both the groups. However, the intergroup comparison of the clinical parameters showed no statistical significance. About 6 out of 10 nonsmokers (60% and 3 smokers (30% showed complete root coverage. The mean percentage of root coverage of 71.2% in nonsmokers and 38% in smokers was observed. Conclusion: The results of the present study suggest that smoking may negatively influence gingival recession reduction and CAL gain. In addition, smokers may exhibit fewer chances of complete root coverage. Overall, nonsmokers showed better improvements in all the parameters compared to smokers at the end of 6 months.

  17. Sub-epithelial connective tissue graft for root coverage in nonsmokers and smokers: A pilot comparative clinical study.

    Science.gov (United States)

    Dwarakanath, Chini Doraswamy; Divya, Bheemavarapu; Sruthima, Gottumukkala Naga Venkata Satya; Penmetsa, Gautami Subadra

    2016-01-01

    Gingival recession is a common condition and is more prevalent in smokers. It is widely believed that root coverage procedures in smokers result in less desirable outcome compared to nonsmokers', and there are few controlled studies in literature to support this finding. Therefore, the purpose of this study was to evaluate and compare the outcome of root coverage with sub-epithelial connective tissue graft (SCTG) in nonsmokers and smokers. A sample of twenty subjects, 10 nonsmokers and 10 smokers were selected each with at least 1 Miller's Class I or II recession on a single rooted tooth. Clinical measurements of probing depth, clinical attachment level (CAL), gingival recession total surface area (GRTSA), depth of recession (RD), width of recession (RW), and width of keratinized tissue were determined at baseline, 3, and 6 months after surgery. The treatment of gingival recession with SCTG and coronally advanced flap showed a decrease in the GRTSA, RD, RW, and an increase in CAL and width of keratinized gingiva in both the groups. However, the intergroup comparison of the clinical parameters showed no statistical significance. About 6 out of 10 nonsmokers (60%) and 3 smokers (30%) showed complete root coverage. The mean percentage of root coverage of 71.2% in nonsmokers and 38% in smokers was observed. The results of the present study suggest that smoking may negatively influence gingival recession reduction and CAL gain. In addition, smokers may exhibit fewer chances of complete root coverage. Overall, nonsmokers showed better improvements in all the parameters compared to smokers at the end of 6 months.

  18. Tunneling endoscopic muscularis dissection for subepithelial tumors originating from the muscularis propria of the esophagus and gastric cardia.

    Science.gov (United States)

    Liu, Bing-Rong; Song, Ji-Tao; Kong, Ling-Jian; Pei, Feng-Hua; Wang, Xin-Hong; Du, Ya-Ju

    2013-11-01

    Endoscopic resection of esophageal or cardial subepithelial tumors (SETs) originating from the muscularis propria (MP) is rarely done due to the high risk of perforation, fistula formation, and secondary infection. The aim of this study was to evaluate the preliminary clinical feasibility and safety of tunneling endoscopic muscularis dissection (tEMD) for resection of SETs located in the esophagus and gastric cardia Twelve patients with SETs originating from the MP of the esophagus (n = 7) or cardia (n = 5) were treated by tEMD. The procedure included creation of a submucosal tunnel to reach the tumor, dissection of the tumor from the surrounding submucosal tissue and the unaffected MP layer, full-thickness resection of the tumor and affected MP, and subsequent closure of the tunnel mucosal entry with endoscopic clips. The en bloc resection rate was 100 % (seven lesions affected the deep MP so complete MP resection was performed; five lesions affected the superficial MP for a partial MP resection). The average tumor size was 18.5 ± 6.9 (range 10-30) mm. The mean operating time was 78.3 ± 25.5 (range 50-130) min. The histological diagnoses were two gastrointestinal stromal tumors with very low risk, nine leiomyomas, and one schwannoma. Air leakage and effusion included subcutaneous and mediastinal emphysema in eight patients (66.7 %), pneumothorax in four (33.3 %), pneumoperitoneum in three (25.0 %), and small pleural effusion in two (16.7 %). All air leakage and effusion cases were resolved with conservative management. No patient developed delayed hemorrhage and chronic fistula after tEMD. During the mean follow-up time of 7.1 ± 4.3 (range 2-15) months, no tumor recurrence was found in any patient. tEMD appears to be a feasible minimally invasive and effective treatment for patients with SETs originating from the MP layer of the esophagus and cardia.

  19. Clinical Comparison of Subepithelial Connective Tissue Grafts and Coronally Advanced Flaps with Emdogain in the Treatment of Gingival Recessions

    Directory of Open Access Journals (Sweden)

    F. Haghighati

    2007-03-01

    Full Text Available Objective: The aim of this study was to compare subepithelial connective tissue grafts (SCTG and coronally advanced flaps (CAF with the addition of Emdogain in the treatment of gingival recession.Materials and Methods: This interventional randomized controlled clinical trial involved eleven patients and 31 teeth demonstrating facial recessions of > 2 mm identified as Miller’s class I or II. Recession depth (RD, recession width (RW, probing depth (PD, clinical attachment level (CAL, and keratinized tissue (KT, weremeasured at baseline and at 4, 12 and 24 weeks postoperation. Before surgery the samples were randomized to receive either a CAF with Emdogain (test group or a connective tissue graft (control group. Data were analyzed using independent t-test and univariate analysis of variance.Results: Twenty-four weeks after therapy, the mean root coverage in the test and control cases was 50.24% and 65.82%, respectively. There was no significant difference between the two groups (P=0.759. Within the 24-week follow-up period both procedures resulted in statistically significant improvement in RD, RW and CAL, but not in PD. KT increased 0.7 mm in the SCTG group while it decreased 0.5 mm in the Emdogain group (P<0.05.Conclusion: The SCTG procedure provided better results in comparison to CAF with Emdogain. However the later method is easier and less technique-sensitive. Therefore it can be considered as a possible substitute for the treatment of gingival recessions,especially when increasing KT is not required.

  20. Mammoth and Mastodon collagen sequences; survival and utility

    Science.gov (United States)

    Buckley, M.; Larkin, N.; Collins, M.

    2011-04-01

    Near-complete collagen (I) sequences are proposed for elephantid and mammutid taxa, based upon available African elephant genomic data and supported with LC-MALDI-MS/MS and LC-ESI-MS/MS analyses of collagen digests from proboscidean bone. Collagen sequence coverage was investigated from several specimens of two extinct mammoths ( Mammuthus trogontherii and Mammuthus primigenius), the extinct American mastodon ( Mammut americanum), the extinct straight-tusked elephant ( Elephas ( Palaeoloxodon) antiquus) and extant Asian ( Elephas maximus) and African ( Loxodonta africana) elephants and compared between the two ionization techniques used. Two suspected mammoth fossils from the British Middle Pleistocene (Cromerian) deposits of the West Runton Forest Bed were analysed to investigate the potential use of peptide mass spectrometry for fossil identification. Despite the age of the fossils, sufficient peptides were obtained to identify these as elephantid, and sufficient sequence variation to discriminate elephantid and mammutid collagen (I). In-depth LC-MS analyses further failed to identify a peptide that could be used to reliably distinguish between the three genera of elephantids ( Elephas, Loxodonta and Mammuthus), an observation consistent with predicted amino acid substitution rates between these species.

  1. Imaging of collagen deposition disorders using optical coherence tomography

    DEFF Research Database (Denmark)

    Ring, H C; Mogensen, M; Hussain, A A

    2015-01-01

    images from scleroderma patients, both systemic and morphea (10 patients), keloid patients (10 patients) and healthy skin adjacent to keloids (10 patients). RESULTS: OCT images of scarring diseases showed varying degrees of disruption to the skin architecture. OCT characteristics were identified for each...... with ordinary scars, hypertrophic scars, keloid scarring, lichen sclerosus et atrophicus and localized or systemic scleroderma were recruited for this pilot study. Affected tissue and adjacent healthy skin were scanned using OCT and digitally photographed. Density measurements were performed in ImageJ on OCT...... of scleroderma, keloid and healthy skin (P = 0.07). CONCLUSION: The OCT imaging appears to identify different scarring mechanisms, and therefore be of potential use in the assessment of outcomes following non-invasive therapy of e.g. early or progressive lesions....

  2. A comparative clinical study of the efficacy of subepithelial connective tissue graft and acellular dermal matrix graft in root coverage: 6-month follow-up observation.

    Science.gov (United States)

    Thomas, Libby John; Emmadi, Pamela; Thyagarajan, Ramakrishnan; Namasivayam, Ambalavanan

    2013-07-01

    The purpose of this study was to compare the clinical efficacy of subepithelial connective tissue graft and acellular dermal matrix graft associated with coronally repositioned flap in the treatment of Miller's class I and II gingival recession, 6 months postoperatively. Ten patients with bilateral Miller's class I or class II gingival recession were randomly divided into two groups using a split-mouth study design. Group I (10 sites) was treated with subepithelial connective tissue graft along with coronally repositioned flap and Group II (10 sites) treated with acellular dermal matrix graft along with coronally repositioned flap. Clinical parameters like recession height and width, probing pocket depth, clinical attachment level, and width of keratinized gingiva were evaluated at baseline, 90(th) day, and 180(th) day for both groups. The percentage of root coverage was calculated based on the comparison of the recession height from 0 to 180(th) day in both Groups I and II. Intragroup parameters at different time points were measured using the Wilcoxon signed rank test and Mann-Whitney U test was employed to analyze the differences between test and control groups. There was no statistically significant difference in recession height and width, gain in CAL, and increase in the width of keratinized gingiva between the two groups on the 180(th) day. Both procedures showed clinically and statistically significant root coverage (Group I 96%, Group II 89.1%) on the 180(th) day. The results indicate that coverage of denuded root with both subepithelial connective tissue autograft and acellular dermal matrix allograft are very predictable procedures, which were stable for 6 months postoperatively.

  3. Collagen crosslinks in chondromalacia of the patella.

    Science.gov (United States)

    Väätäinen, U; Kiviranta, I; Jaroma, H; Arokosi, J; Tammi, M; Kovanen, V

    1998-02-01

    The aim of the study was to determine collagen concentration and collagen crosslinks in cartilage samples from chondromalacia of the patella. To study the extracellular matrix alterations associated to chondromalacia, we determined the concentration of collagen (hydroxyproline) and its hydroxylysylpyridinoline and lysylpyridinoline crosslinks from chondromalacia foci of the patellae in 12 patients and 7 controls from apparently normal cadavers. The structure of the collagen network in 8 samples of grades II-IV chondromalacia was examined under polarized light microscopy. The full-thickness cartilage samples taken with a surgical knife from chondromalacia lesions did not show changes in collagen, hydroxylysylpyridinoline and lysylpyridinoline concentration as compared with the controls. Polarized light microscopy showed decreased birefringence in the superficial cartilage of chondromalacia lesions, indicating disorganization or disappearance of collagen fibers in this zone. It is concluded that the collagen network shows gradual disorganization with the severity of chondromalacia lesion of the patella without changes in the concentration or crosslinks of collagen.

  4. Clinical Comparison of the Subepithelial Connective Tissue versus Platelet-Rich Fibrin for the Multiple Gingival Recession Coverage on Anterior Teeth Using the Tunneling Technique

    Directory of Open Access Journals (Sweden)

    Victor Fabrizio Cabrera Pazmiño

    2017-01-01

    Full Text Available The aim of this study was to evaluate and compare, clinically, the efficiency of the subepithelial connective tissue graft (SCTG and platelet-rich fibrin (L-PRF using the tunnel technique to cover the multiple gingival recessions on anterior teeth, in the same patient. Within the limits of this study, we conclude that both SCTG and L-PRF proved to be reliable options for the treatment of gingival recessions, efficiently supporting the biological and aesthetic demand, stimulating the periodontal tissues’ health, and bringing reliable and highly predictable results.

  5. Clinical Comparison of the Subepithelial Connective Tissue versus Platelet-Rich Fibrin for the Multiple Gingival Recession Coverage on Anterior Teeth Using the Tunneling Technique

    Science.gov (United States)

    Rodas, Miguel Agusto Riquelme; Cáceres, Carlos David Barrios; Duarte, Guillermo Gustavo Renault; Azuaga, Melanie Vanesa Cano; de Paula, Bruna Luísa; Caliente, Eliana Aparecida; Soares, Simone; Silveira, Elcia Maria Varize

    2017-01-01

    The aim of this study was to evaluate and compare, clinically, the efficiency of the subepithelial connective tissue graft (SCTG) and platelet-rich fibrin (L-PRF) using the tunnel technique to cover the multiple gingival recessions on anterior teeth, in the same patient. Within the limits of this study, we conclude that both SCTG and L-PRF proved to be reliable options for the treatment of gingival recessions, efficiently supporting the biological and aesthetic demand, stimulating the periodontal tissues' health, and bringing reliable and highly predictable results. PMID:28695021

  6. 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.

  7. Fracture mechanics of collagen fibrils

    DEFF Research Database (Denmark)

    Svensson, Rene B; Mulder, Hindrik; Kovanen, Vuokko

    2013-01-01

    Tendons are important load-bearing structures, which are frequently injured in both sports and work. Type I collagen fibrils are the primary components of tendons and carry most of the mechanical loads experienced by the tissue, however, knowledge of how load is transmitted between and within fib...

  8. Kinetic hysteresis in collagen folding.

    Science.gov (United States)

    Mizuno, Kazunori; Boudko, Sergei P; Engel, Jürgen; Bächinger, Hans Peter

    2010-06-16

    The triple helix of collagen shows a steep unfolding transition upon heating, whereas less steep and more gradual refolding is observed upon cooling. The shape of the hysteresis loop depends on the rate of temperature change as well as the peptide concentration. Experimental heating and cooling rates are usually much faster than rates of unfolding and refolding. In this work, collagen model peptides were used to study hysteresis quantitatively. Their unfolding and refolding profiles were recorded at different heating and cooling rates, and at different peptide concentrations. Data were fitted assuming kinetic mechanisms in which three chains combine to a helix with or without an intermediate that acts as a nucleus. A quantitative fit was achieved with the same kinetic model for the forward and backward reactions. Transitions of exogenously trimerized collagen models were also analyzed with a simplified kinetic mechanism. It follows that true equilibrium transitions can only be measured at high concentrations of polypeptide chains with slow scanning rates, for example, 0.1 degrees C/h at 0.25 mM peptide concentration of (Gly-Pro-Pro)(10). (Gly-Pro-4(R)Hyp)(10) folds approximately 2000 times faster than (Gly-Pro-Pro)(10). This was explained by a more stable nucleus, whereas the rate of propagation was almost equal. The analysis presented here can be used to derive kinetic and thermodynamic data for collagenous and other systems with kinetically controlled hysteresis. (c) 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  9. Collagen content and types in trachomatous conjunctivitis.

    Science.gov (United States)

    Abu el-Asrar, A M; Geboes, K; al-Kharashi, S A; Tabbara, K F; Missotten, L

    1998-01-01

    To study alterations in conjunctival collagen in the conjunctiva of patients with active trachoma. We studied conjunctival biopsy specimens obtained from nine subjects with active trachoma and from four control subjects. We used immunohistochemical techniques and a panel of monoclonal and polyclonal antibodies directed against types I, III, IV and V collagen. In normal conjunctiva, the staining for types I and III collagen was localised to the substantia propria. Type IV collagen was located in the epithelial and capillary endothelial basement membranes. The staining for type V collagen was absent. In trachoma biopsy specimens, staining for types I and III collagen showed collagen fibrils among epithelial cells, patchy increase in staining intensity in the upper stroma, and thicker and irregularly arranged collagen fibrils in the substantia propria. Staining for type IV collagen showed irregularly thickened epithelial basement membrane. Staining for type V collagen showed patchy staining in the upper substantia propria; it was also noted in the cytoplasm of fibroblasts, in the walls of blood vessels in the substantia propria, and in the walls of accessory lacrimal glands. Our data indicate new type V collagen formation, and increased types I, III and IV collagen content, in the conjunctiva from patients with active trachoma.

  10. Contact activation of blood coagulation on a defined kaolin/collagen surface in a microfluidic assay.

    Science.gov (United States)

    Zhu, Shu; Diamond, Scott L

    2014-12-01

    Generation of active Factor XII (FXIIa) triggers blood clotting on artificial surfaces and may also enhance intravascular thrombosis. We developed a patterned kaolin (0 to 0.3 pg/μm(2))/type 1 collagen fibril surface for controlled microfluidic clotting assays. Perfusion of whole blood (treated only with a low level of 4 μg/mL of the XIIa inhibitor, corn trypsin inhibitor) drove platelet deposition followed by fibrin formation. At venous wall shear rate (100 s(-1)), kaolin accelerated onset of fibrin formation by ~100 sec when compared to collagen alone (250 sec vs. 350 sec), with little effect on platelet deposition. Even with kaolin present, arterial wall shear rate (1000 s(-1)) delayed and suppressed fibrin formation compared to venous wall shear rate. A comparison of surfaces for extrinsic activation (tissue factor TF/collagen) versus contact activation (kaolin/collagen) that each generated equal platelet deposition at 100 s(-1) revealed: (1) TF surfaces promoted much faster fibrin onset (at 100 sec) and more endpoint fibrin at 600 sec at either 100 s(-1) or 1000 s(-1), and (2) kaolin and TF surfaces had a similar sensitivity for reduced fibrin deposition at 1000 s(-1) (compared to fibrin formed at 100 s(-1)) despite differing coagulation triggers. Anti-platelet drugs inhibiting P2Y1, P2Y12, cyclooxygenase-1 or activating IP-receptor or guanylate cyclase reduced platelet and fibrin deposition on kaolin/collagen. Since FXIIa or FXIa inhibition may offer safe antithrombotic therapy, especially for biomaterial thrombosis, these defined collagen/kaolin surfaces may prove useful in drug screening tests or in clinical diagnostic assays of blood under flow conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Site-specific immunostaining for type X collagen in noncalcified articular cartilage of canine stifle knee joint.

    Science.gov (United States)

    Lammi, P E; Lammi, M J; Hyttinen, M M; Panula, H; Kiviranta, I; Helminen, H J

    2002-12-01

    Type X collagen is a short-chain collagen that is strongly expressed in hypertrophic chondrocytes. In this study, we used an immunohistochemical technique exploiting a prolonged hyaluronidase unmasking of type X collagen epitopes to show that type X collagen is not restricted to calcified cartilage, but is also present in normal canine noncalcified articular cartilage. A 30 degrees valgus angulation procedure of the right tibia was performed in 15 dogs at the age of 3 months, whereas their nonoperated sister dogs served as controls. Samples were collected 7 and 18 months after the surgery and immunostained for type X collagen. The deposition of type X collagen increased during maturation from age 43 weeks to 91 weeks. In the patella, most of the noncalcified cartilage stained for type X collagen, whereas, in the patellar surface of the femur, it was present mainly in the femoral groove close to cartilage surface. In femoral condyles, the staining localized mostly in the superficial cartilage on the lateral and medial sides, but not in the central weight-bearing area. In tibial condyles, type X collagen was often observed close to the cartilage surface in medial parts of the condyles, although staining could also be seen in the deep zone of the cartilage. Staining for type X collagen appeared strongest at sites where the birefringence of polarized light was lowest, suggesting a colocalization of type X collagen with the collagen fibril arcades in the intermediate zone. No significant difference in type X collagen immunostaining was observed in lesion-free articular cartilage between controls and dogs that underwent a 30 degrees valgus osteotomy. In osteoarthritic lesions, however, there was strong immunostaining for both type X collagen and collagenase-induced collagen cleavage products. The presence of type X collagen in the transitional zone of cartilage in the patella, femoropatellar groove, and in tibial cartilage uncovered by menisci suggests that it may

  12. Post-translational control of collagen fibrillogenesis in mineralizing cultures of chick osteoblasts

    Science.gov (United States)

    Gerstenfeld, L. C.; Riva, A.; Hodgens, K.; Eyre, D. R.; Landis, W. J.

    1993-01-01

    Cultured osteoblasts from chick embryo calvaria were used as a model system to investigate the post-translational extracellular mechanisms controlling the macroassembly of collagen fibrils. The results of these studies demonstrated that cultured osteoblasts secreted a collagenous extracellular matrix that assembled and mineralized in a defined temporal and spatial sequence. The assembly of collagen occurred in a polarized fashion, such that successive orthogonal arrays of fibrils formed between successive cell layers proceeding from the culture surface toward the media. Mineralization followed in the same manner, being observed first in the deepest and oldest fibril layers. Collagen fibrillogenesis, the kinetics of cross-link formation, and collagen stability in the extracellular matrix of the cultures were examined over a 30 day culture period. Between days 8 and 12 in culture, collagen fibril diameters increased from lysyl pyridinoline (LP), showed that these mature cross-links increased from undetectable levels to concentrations found in normal chick bone. Analysis of the kinetics of their formation by pulse-chase labeling the cultures with [3H]lysine showed a doubling time of approximately 5 days. The relationships between cross-link formation, fibrillogenesis, and collagen stability were examined in cultures treated with beta-aminopropionitrile (beta-APN), a potent inhibitor of lysyl oxidase and cross-link formation. In beta-APN-treated cultures, total collagen synthesis was increased twofold, with no change in mRNA levels for type I collagen, whereas the amount of collagen accumulated in the cell layer was decreased by 50% and mineral deposition was reduced. The rate of collagen retention in the matrix was assessed by pulse-chase analysis of [3H]proline over a 16 day period in control and beta-APN-treated cultures. In control cultures, about 20% of the labeled collagen was lost from the cell layers over a 16 day period compared with > 80% in the presence of

  13. Prognostic significance of the expression of MUC1 and collagen type IV in advanced gastric carcinoma.

    Science.gov (United States)

    Ando, H; Aihara, R; Ohno, T; Ogata, K; Mochiki, E; Kuwano, H

    2009-08-01

    Scirrhous gastric carcinoma is characterized by excessive deposition of collagen in the stroma. However, the clinical significance of this fibrosis of the stomach has not been clarified. The aim of this study was to examine the fibrotic mechanism in several histological types of gastric carcinoma, and the combination of MUC1 and collagen type IV as a possible predictor of patient survival. One hundred and two paraffin-embedded specimens of gastric carcinoma were examined by immunohistochemical staining using monoclonal antibodies against collagen type IV and MUC1. Collagen type IV-positive expression was significantly associated with depth of wall penetration (P = 0.025) and stage (P = 0.023). There was a significant relationship between MUC1-positive expression and interstitial collagen type IV-positive expression (P = 0.035). Survival was shorter for patients with the combination of MUC1-positive expression and interstitial collagen type IV-negative expression than for those with other expression patterns. In patients with differentiated-type advanced gastric carcinoma, the combination of MUC1-positive and interstitial collagen type IV-negative expression may be a marker of unfavourable prognosis. Copyright 2009 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

  14. Fabrication of nano-hydroxyapatite/collagen/osteonectin composites for bone graft applications

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Susan; Ngiam, Michelle; Chan, Casey K; Ramakrishna, S [Division of Bioengineering, Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, 117576 (Singapore)

    2009-04-15

    Mineralized type I collagen (collagen I) nanofibers and their nanofibril bundles make up the microstructure of natural bone tissue, which range from nanometers to micrometers. However, attempts to achieve this hierarchically assembled structure in vitro have been unsuccessful. In this study, we added osteonectin into the collagen I solution, either at a high or low weight ratio (osteonectin: collagen I = 1:30 or 1:90) before co-precipitation. Results indicated that spindle-like nano-hydroxyapatite (nano-HA) was deposited on collagen/osteonectin and pure osteonectin (control) groups. Furthermore, transmission electron microscope (TEM) and scanning electron microscope (SEM) results showed that the assembled mineralized fiber bundles were formed randomly at different levels from 50 nm, 250 nm to 1100 nm. However, when we replaced collagen I with collagen II, osteonectin addition did not induce the formation of mineralized fiber bundles. The participation of osteonectin in the assembly of the mineralized fibers could provide new insights into the novel mineralization function of osteonectin for bone development in vivo and advancing new biomimetic methods for bone graft applications.

  15. Changes in histoanatomical distribution of types I, III and V collagen promote adaptative remodeling in posterior tibial tendon rupture

    Directory of Open Access Journals (Sweden)

    Érika Satomi

    2008-01-01

    Full Text Available INTRODUCTION: Posterior tibial tendon dysfunction is a common cause of adult flat foot deformity, and its etiology is unknown. PURPOSE: In this study, we characterized the morphologic pattern and distribution of types I, III and V collagen in posterior tibial tendon dysfunction. METHOD: Tendon samples from patients with and without posterior tibial tendon dysfunction were stained by immunofluorescence using antibodies against types I, III and V collagen. RESULTS: Control samples showed that type V deposited near the vessels only, while surgically obtained specimens displayed type V collagen surrounding other types of collagen fibers in thicker adventitial layers. Type III collagen levels were also increased in pathological specimens. On the other hand, amounts of collagen type I, which represents 95% of the total collagen amount in normal tendon, were decreased in pathological specimens. CONCLUSION: Fibrillogenesis in posterior tibial tendon dysfunction is altered due to higher expression of types III and V collagen and a decreased amount of collagen type I, which renders the originating fibrils structurally less resistant to mechanical forces.

  16. Collagens in the aged human macular sclera.

    Science.gov (United States)

    Marshall, G E; Konstas, A G; Lee, W R

    1993-02-01

    Scleral tissue from the region of the human macula was studied by the immunogold labeling technique (cryoultramicrotomy and LR white resin embedding) in an attempt to identify the fine structural distribution of collagen types I-VI. Labeling of the striated collagen fibrils suggested colocalisation of collagen types I, III and V with type V occurring at the fibril surface. Both types V and VI collagen were localised to filamentous strands in the interfibrillar matrix. Collagen types II and IV were absent from the scleral stroma.

  17. Predictability and stability of laser-assisted subepithelial keratectomy with mitomycin C for the correction of high myopia.

    Science.gov (United States)

    Iu, Lawrence P L; Fan, Michelle C Y; Chen, Ivan N; Lai, Jimmy S M

    2017-06-01

    The purpose of this study was to evaluate the predictability and stability of laser-assisted subepithelial keratectomy (LASEK) with mitomycin C (MMC) in correction of high myopia (≤-6.0 diopters [D]) as compared to low-to-moderate myopia (>-6.0 D).This is a retrospective, comparative, cohort study which included 43 eyes of 43 consecutive patients who underwent LASEK with MMC in a private hospital in Hong Kong by a single surgeon. Twenty-five eyes had high myopia (mean spherical equivalent [SE] = -8.53 ± 1.82 D) and 18 eyes had low-to-moderate myopia (mean SE = -3.99 ± 1.37 D) before surgery.In terms of refractive predictability, mean SE was significantly better in eyes with preoperative low-to-moderate myopia than high myopia at 6 months (0.04 ± 0.23 vs 0.31 ± 0.52 D, P = .035). In terms of refractive stability, between 1 and 3 months, both groups had mean absolute change of SE of around 0.25 D. Between 3 and 6 months, preoperative low-to-moderate myopia group had significantly less absolute change of SE compared to high myopia group (0.07 vs 0.23 D, P = .003). More eyes with preoperative high myopia changed SE by more than 0.25 D than those with low-to-moderate myopia between 3 and 6 months (32.0% vs 5.6%, P = .057).In conclusion, LASEK with MMC is more unpredictable and unstable in correction of high myopia than low-to-moderate myopia. The refractive outcome of most low-to-moderate myopia correction stabilizes at 3 months. Stability is not achieved until after 6 months in high myopia correction.

  18. Differentiation of large (≥5 cm) gastrointestinal stromal tumors from benign subepithelial tumors in the stomach: Radiologists’ performance using CT

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ye Ra [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Kim, Se Hyung, E-mail: shkim7071@gmail.com [Department of Radiology, Seoul National University Hospital (Korea, Republic of); The Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of); Kim, Sun-Ah [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Shin, Cheong-il [Department of Radiology, Seoul National University Hospital (Korea, Republic of); The Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of); Kim, Hyung Jin; Kim, Seong Ho [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Han, Joon Koo; Choi, Byung Ihn [Department of Radiology, Seoul National University Hospital (Korea, Republic of); The Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of)

    2014-02-15

    Purpose: To identify significant CT findings for the differentiation of large (≥5 cm) gastric gastrointestinal stromal tumors (GIST) from benign subepithelial tumors and to assess whether radiologists’ performance in differentiation is improved with knowledge of significant CT criteria. Materials and methods: One-hundred twenty patients with pathologically proven large (≥5 cm) GISTs (n = 99), schwannomas (n = 16), and leiomyomas (n = 5) who underwent CT were enrolled. Two radiologists (A and B) retrospectively reviewed their CT images in consensus for the location, size, degree and pattern of enhancement, contour, growth pattern and the presence of calcification, necrosis, surface ulceration, or enlarged lymph nodes. CT findings considered significant for differentiation were determined using uni- and multivariate statistical analyses. Thereafter, two successive review sessions for the differentiation of GIST from non-GIST were independently performed by two other reviewers (C and D) with different expertise of 2 and 9 years using a 5-point confidence scale. At the first session, reviewers interpreted CT images without knowledge of significant CT findings. At the second session, the results of statistical analyses were provided to the reviewers. To assess improvement in radiologists’ performance, a pairwise comparison of receiver operating curves (ROC) was performed. Results: Heterogeneous enhancement, presence of necrosis, absence of lymph nodes, and mean size of ≥6 cm were found to be significant for differentiating GIST from schwannoma (P < 0.05). Non-cardial location, heterogeneous enhancement, and presence of necrosis were differential CT features of GIST from leiomyoma (P < 0.05). Multivariate analyses indicated that absence of enlarged LNs was the only statistically significant variable for GIST differentiating from schwannoma. The area under the curve of both reviewers obtained using ROC significantly increased from 0.682 and 0.613 to 0.903 and 0

  19. Sequential adhesion of platelets and leukocytes from flowing whole blood onto a collagen-coated surface: requirement for a GpVI-binding site in collagen.

    Science.gov (United States)

    Butler, Lynn M; Metson-Scott, Tom; Felix, Jo; Abhyankar, Anita; Rainger, G Ed; Farndale, Richard W; Watson, Stephen P; Nash, Gerard B

    2007-05-01

    The adhesion of leukocytes to immobilised platelets may contribute to inflammatory and thrombotic responses in damaged tissue. To investigate the conditions under which platelets and leukocytes might be deposited together in vessels, we perfused fluorescently-labelled whole blood through glass capillaries coated with various collagen preparations. Video-microscopic observations of the surface showed that platelets formed numerous, individual, rolling and stationary attachments to surfaces coated with acid-soluble, monomeric collagen. However, leukocyte interactions with the deposited platelets were rare. If the blood was washed out, the adherent platelets became more activated, and many rolling adherent leukocytes were observed if a second bolus of blood was perfused over them. This suggested that platelet activation had initially been inadequate to support leukocyte capture. Next, fibrillar collagen was adsorbed to the capillaries to present an ordered array of peptide motifs to platelet receptor glycoprotein (Gp)VI and transduce an activating signal. In this case, platelets were deposited in discrete, stable aggregates and the bound platelets captured many flowing leukocytes. Alternatively, acid-soluble collagen was seeded with collagen-related peptide (CRP) known to contain a GpVI-binding motif. Again, platelet adhesion became stable, and numerous flowing leukocytes were captured. Addition of antibody against GpVI or against P-selectin greatly reduced leukocyte adhesion to the platelets. Thus, in whole blood, platelets binding to exposed collagen need to be activated through GpVI in order to expose sufficient P-selectin to allow efficient capture of flowing leukocytes to take place.

  20. A modified collagen scaffold facilitates endogenous neurogenesis for acute spinal cord injury repair.

    Science.gov (United States)

    Fan, Caixia; Li, Xing; Xiao, Zhifeng; Zhao, Yannan; Liang, Hui; Wang, Bin; Han, Sufang; Li, Xiaoran; Xu, Bai; Wang, Nuo; Liu, Sumei; Xue, Weiwei; Dai, Jianwu

    2017-03-15

    Due to irreversible neuronal loss and glial scar deposition, spinal cord injury (SCI) ultimately results in permanent neurological dysfunction. Neuronal regeneration of neural stem cells (NSCs) residing in the spinal cord could be an ideal strategy for replenishing the lost neurons and restore function. However, many myelin-associated inhibitors in the SCI microenvironment limit the ability of spinal cord NSCs to regenerate into neurons. Here, a linearly ordered collagen scaffold was used to prevent scar deposition, guide nerve regeneration and carry drugs to neutralize the inhibitory molecules. A collagen-binding EGFR antibody Fab fragment, CBD-Fab, was constructed to neutralize the myelin inhibitory molecules, which was demonstrated to promote neuronal differentiation and neurite outgrowth under myelin in vitro. This fragment could also specifically bind to the collagen and undergo sustained release from collagen scaffold. Then, the scaffolds modified with CBD-Fab were transplanted into an acute rat SCI model. The robust neurogenesis of endogenous injury-activated NSCs was observed, and these NSCs could not only differentiate into neurons but further mature into functional neurons to reconnect the injured gap. The results indicated that the modified collagen scaffold could be an ideal candidate for spinal cord regeneration after acute SCI. A linearly ordered collagen scaffold was specifically modified with collagen-binding EGFR antibody, allowed for sustained release of this EGFR neutralizing factor, to block the myelin associated inhibitory molecules and guide spinal cord regeneration along its linear fibers. Dorsal root ganglion neurons and neural stem cells induced by CBD-Fab exhibited enhanced neurite outgrowth and neuronal differentiation rate under myelin in vitro. Transplantation of the modified collagen scaffold with moderate EGFR neutralizing proteins showed greatest advantage on endogenous neurogenesis of injury-activated neural stem cells for acute

  1. Subepithelial connective tissue graft associated with apicoectomy and root-end fillings in the treatment of deep localized gingival recession with apex root exposure: case report.

    Science.gov (United States)

    Kahn, Sergio; Egreja, Andre Medina Coeli; Barceleiro, Marcos de Oliveira

    2009-08-01

    Periodontal reconstructive surgery procedures seek to correct mucogingival defects, including gingival recession. This case report describes the use of a subepithelial connective tissue graft (SCTG) associated with root-end fillings using mineral trioxide aggregate (MTA) for the treatment of Miller Class II recession with root apex exposure. A partial-thickness double pedicle flap was made, followed by root preparation with curette and bur finishing. The exposed root apex was removed and the canal was filled with MTA. An SCTG taken from the palate was placed over the root surface and covered with the double pedicle flap. Twelve months after treatment, a reduction from 11 mm to 1 mm in gingival recession was achieved, covering 91% of the root. Repair in the periapical region was determined with radiographs. A 1.0-mm probing depth was measured, and no bleeding was observed on probing. There was an adequate keratinized tissue band, along with esthetic tissue contour and coloration. This case report serves as an example of how the grafting of subepithelial connective tissue can be successfully accomplished in tandem with MTA for the treatment of isolated Miller Class II gingival recession with root apex exposure. (Int J Periodontics Restorative Dent 2009;29:445-449.).

  2. Detection of collagen by second harmonic microscopy as a diagnostic tool for liver fibrosis

    Science.gov (United States)

    Banavar, Maruth; Kable, Eleanor P. W.; Braet, Filip; Wang, X. M.; Gorrell, M. D.; Cox, Guy

    2006-02-01

    Liver fibrosis has many causes, including hepatitis C, alcohol abuse, and non-alcoholic steatohepatitis. It is characterized by abnormal deposition of extracellular matrix proteins, mainly collagen. The deposition of these proteins results in impaired liver function caused by distortion of the hepatic architecture by fibrous scar tissue. The unique triple helix structure of collagen and high level of crystallinity make it very efficient for generating second harmonic signals. In this study we have set out to see if second harmonic imaging of collagen can be used as a non-biased quantitative tool for classification of fibrosis levels in liver biopsies and if it can detect early fibrosis formation not detected by current methods.

  3. 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.

  4. Collagen XXIV, a vertebrate fibrillar collagen with structural features of invertebrate collagens: selective expression in developing cornea and bone.

    Science.gov (United States)

    Koch, Manuel; Laub, Friedrich; Zhou, Peihong; Hahn, Rita A; Tanaka, Shizuko; Burgeson, Robert E; Gerecke, Donald R; Ramirez, Francesco; Gordon, Marion K

    2003-10-31

    Tissue-specific assembly of fibers composed of the major collagen types I and II depends in part on the formation of heterotypic fibrils, using the quantitatively minor collagens V and XI. Here we report the identification of a new fibrillar-like collagen chain that is related to the fibrillar alpha1(V), alpha1(XI), and alpha2(XI) collagen polypeptides and which is coexpressed with type I collagen in the developing bone and eye. The new collagen was designated the alpha1(XXIV) chain and consists of a long triple helical domain flanked by typical propeptide-like sequences. The carboxyl propeptide is classic, with 8 conserved cysteine residues. The amino-terminal peptide contains a thrombospodin-N-terminal-like (TSP) motif and a highly charged segment interspersed with several tyrosine residues, like the fibril diameter-regulating collagen chains alpha1(V) and alpha1(XI). However, a short imperfection in the triple helix makes alpha1(XXIV) unique from other chains of the vertebrate fibrillar collagen family. The triple helical interruption and additional select features in both terminal peptides are common to the fibrillar chains of invertebrate organisms. Based on these data, we propose that collagen XXIV is an ancient molecule that may contribute to the regulation of type I collagen fibrillogenesis at specific anatomical locations during fetal development.

  5. Immunostimulation effect of jellyfish collagen.

    Science.gov (United States)

    Sugahara, Takuya; Ueno, Masashi; Goto, Yoko; Shiraishi, Ryusuke; Doi, Mikiharu; Akiyama, Koichi; Yamauchi, Satoshi

    2006-09-01

    Certain edible large jellyfishes belonging to the order Rhizostomeae are consumed in large quantities in China and Japan. The exumbrella part of the edible jellyfish Stomolophus nomurai was cut and soaked in dilute hydrochloric acid solution (pH 3.0) for 12 h, and heated at 121 degrees C for 20 min. The immunostimulation effects of the jellyfish extract were examined. The jellyfish extract enhanced IgM production of human hybridoma HB4C5 cells 34-fold. IgM and IgG production of human peripheral blood lymphocytes (PBL) were also accelerated, 2.8- and 1.4-fold respectively. Moreover, production of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha by human PBL was stimulated 100- and 17-fold respectively. Collagenase treatment inactivated the immunostimulation activity of the jellyfish extract. In addition, purified collagen from bovine Achilles' tendon accelerated IgM production of hybridoma cells. These facts mean that collagen has an immunostimulation effect, and that the active substance in jellyfish extract is collagen.

  6. Collagen telopeptides (cross-linking sites) play a role in collagen gel lattice contraction

    Science.gov (United States)

    Woodley, D. T.; Yamauchi, M.; Wynn, K. C.; Mechanic, G.; Briggaman, R. A.

    1991-01-01

    Solubilized interstitial collagens will form a fibrillar, gel-like lattice when brought to physiologic conditions. In the presence of human dermal fibroblasts the collagen lattice will contract. The rate of contraction can be determined by computer-assisted planemetry. The mechanisms involved in contraction are as yet unknown. Using this system it was found that the rate of contraction was markedly decreased when collagen lacking telopeptides was substituted for native collagen. Histidinohydroxylysinonorleucine (HHL) is a major stable trifunctional collagen cross-link in mature skin that involves a carboxyl terminal, telopeptide site 16c, the sixteenth amino acid residue from the carboxy terminal of the telopeptide region of alpha 1 (I) in type I collagen. Little, if any, HHL was present in native, purified, reconstituted, soluble collagen fibrils from 1% acetic acid-extracted 2-year-old bovine skin. In contrast, HHL cross-links were present (0.22 moles of cross-link per mole of collagen) in lattices of the same collagen contracted by fibroblasts. However, rat tail tendon does not contain HHL cross-links, and collagen lattices made of rat tail tendon collagen are capable of contraction. This suggests that telopeptide sites, and not mature HHL cross-links per se, are essential for fibroblasts to contract collagen lattices. Beta-aminopropionitrile fumarate (BAPN), a potent lathyrogen that perturbs collagen cross-linking by inhibition of lysyl oxidase, also inhibited the rate of lattice cell contraction in lattices composed of native collagen. However, the concentrations of BAPN that were necessary to inhibit the contraction of collagen lattices also inhibited fibroblast growth suggestive of cellular toxicity. In accordance with other studies, we found no inhibition of the rate of lattice contraction when fibronectin-depleted serum was used. Electron microscopy of contracted gels revealed typical collagen fibers with a characteristic axial periodicity. The data

  7. DSC Study of Collagen in Disc Disease

    Directory of Open Access Journals (Sweden)

    S. Skrzyński

    2009-01-01

    Full Text Available Differential scanning calorimetry (DSC has been used to estimate the effect of disc disease on the collagen helix-coil transition and morphology for tissue extracted from patients during surgical operation. Forty discs were obtained from patients with degenerative disc disease undergoing surgery for low back pain. The patients were in the age between 20 and 70 years old. The specimens were kept wet during DSC experiment. The data allow the comparison between thermal stability of collagen tissue from healthy patients and from patients suffering from disc disease. In the paper the comparison between thermal helix-coil transition for collagen fibers from patients suffering from disc disease and collagen fibers from healthy organisms has been discussed. The heating rate has an influence on the position on denaturation temperatures of collagen in disc tissues. Higher helix-coil transition temperature of collagen in degenerated disc suggests that additional intermolecular cross linking of collagen fibers occurs. Denaturation temperatures of collagen in degenerated male disc possess smaller values than in female ones. Disc disease induces changes in collagen structure and leads to formation of additional crosslinks between collagen fibers.

  8. Stress controls the mechanics of collagen networks

    Science.gov (United States)

    Licup, Albert James; Münster, Stefan; Sharma, Abhinav; Sheinman, Michael; Jawerth, Louise M.; Fabry, Ben; Weitz, David A.; MacKintosh, Fred C.

    2015-01-01

    Collagen is the main structural and load-bearing element of various connective tissues, where it forms the extracellular matrix that supports cells. It has long been known that collagenous tissues exhibit a highly nonlinear stress–strain relationship, although the origins of this nonlinearity remain unknown. Here, we show that the nonlinear stiffening of reconstituted type I collagen networks is controlled by the applied stress and that the network stiffness becomes surprisingly insensitive to network concentration. We demonstrate how a simple model for networks of elastic fibers can quantitatively account for the mechanics of reconstituted collagen networks. Our model points to the important role of normal stresses in determining the nonlinear shear elastic response, which can explain the approximate exponential relationship between stress and strain reported for collagenous tissues. This further suggests principles for the design of synthetic fiber networks with collagen-like properties, as well as a mechanism for the control of the mechanics of such networks. PMID:26195769

  9. A novel functional role of collagen glycosylation

    DEFF Research Database (Denmark)

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

    2011-01-01

    Collagens make up the most abundant component of interstitial extracellular matrices and basement membranes. Collagen remodeling is a crucial process in many normal physiological events and in several pathological conditions. Some collagen subtypes contain specific carbohydrate side chains......, 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...

  10. IGF-II and collagen expression by keratocytes during postnatal development.

    Science.gov (United States)

    Kane, Bradley P; Jester, James V; Huang, Jiying; Wahlert, Andrew; Hassell, John R

    2009-08-01

    Keratocytes produce the extensive stromal matrix of the cornea during the late embryonic and neonatal time periods. We propose to test the hypothesis that their biosynthetic activity declines during this process. Keratocytes were isolated from corneas of 6-8-week-old rabbits and corneas of 1-2-year-old cows and their ability to proliferate and synthesize collagen in serum-free media was determined. Rabbit keratocyte cultures increased 38% in DNA content after one week and deposited collagen type I and IGF-II in the media. Bovine keratocyte cultures, in contrast, did not increase in DNA or produce detectable collagen and IGF-II. Bovine keratocytes cultured in media previously conditioned by rabbit keratocytes, however, increased 56% in DNA content, and deposited collagen type I into the media. Microarray analysis of mRNA from neonatal and adult mouse keratocytes was used to confirm these differences. Compared to adult mouse keratocytes, neonatal keratocytes showed high expression levels of IGF-I, IGF-II and collagen types III and V. Since previous studies showed that IGFs stimulate bovine keratocytes to proliferate and to synthesize procollagen type I, we therefore propose that the results of this study suggests that the IGFs may play an important role in regulating early corneal growth in vivo.

  11. Alginate-Collagen Fibril Composite Hydrogel

    Directory of Open Access Journals (Sweden)

    Mahmoud Baniasadi

    2015-02-01

    Full Text Available We report on the synthesis and the mechanical characterization of an alginate-collagen fibril composite hydrogel. Native type I collagen fibrils were used to synthesize the fibrous composite hydrogel. We characterized the mechanical properties of the fabricated fibrous hydrogel using tensile testing; rheometry and atomic force microscope (AFM-based nanoindentation experiments. The results show that addition of type I collagen fibrils improves the rheological and indentation properties of the hydrogel.

  12. Fabrication of polycaprolactone collagen hydrogel constructs seeded with mesenchymal stem cells for bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Reichert, J C; Berner, A [Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane (Australia); Heymer, A; Eulert, J; Noeth, U, E-mail: johannes.reichert@qut.edu.a [Orthopaedic Institute, Division of Tissue Engineering, Koenig-Ludwig-Haus, Julius-Maximilians-University, Wuerzburg (Germany)

    2009-12-15

    The osteogenic differentiation of bone marrow-derived human mesenchymal stem cells (MSCs) in a collagen I hydrogel was investigated. Collagen hydrogels with 7.5 x 10{sup 5} MSCs ml{sup -1} were fabricated and cultured for 6 weeks in a defined, osteogenic differentiation medium. Histochemistry revealed morphologically distinct, chondrocyte-like cells, surrounded by a sulfated proteoglycan-rich extracellular matrix in the group treated with bone morphogenetic protein 2 (BMP-2), while cells cultured with dexamethasone, ascorbate-2-phosphate, and beta-glycerophosphate displayed a spindle-shaped morphology and deposited a mineralized matrix. Real-time polymerase chain reaction (RT-PCR) analyses revealed a specific chondrogenic differentiation with the expression of cartilage-specific markers in the BMP-2-treated group and a distinct expression pattern of the osteogenic markers alkaline phosphatase (ALP), type I collagen, osteocalcin (OC), and cbfa-1 in the group treated with an osteogenic standard medium. The collagen gels were used to engineer a cell laden medical grade epsilon-polycaprolactone (PCL)-hydrogel construct for segmental bone repair showing good bonding at the scaffold hydrogel interface and even cell distribution. The results show that MSCs cultured in a collagen I hydrogel are able to undergo a distinct osteogenic differentiation pathway when stimulated with specific differentiation factors and suggest that collagen I hydrogels are a suitable means to facilitate cell seeding of scaffolds for bone tissue engineering applications.

  13. Fluoride alters type I collagen expression in the early stages of odontogenesis.

    Science.gov (United States)

    Maciejewska, I; Spodnik, J H; Domaradzka-Pytel, B; Sidor-Kaczmarek, J; Bereznowski, Z

    2006-11-01

    Fluoride alters the expression and post-translational modifications of extracellular matrix proteins in dentin. The aim of our study was to determine the effects of fluoride on type I collagen expression during the early stages of tooth germ development in rats. Pregnant dams were divided into three groups and fed a standard diet. From the fifth day of pregnancy the three groups received tap water with, respectively, trace amounts of fluoride (C), a low fluoride concentration (FL) or and a high fluoride concentration (FH). Changes in type I collagen expression and distribution were evaluated. The expression of type I collagen was restricted to the extracellular spaces of cells of mesenchymal origin. In the youngest animals the most intense immunoreactivity for type I collagen was detected in predentin of the FL group. Although the intensity of immunostaining increased in proportion to the age of the animals, the largest increase in the groups investigated was detected in the FL group. We concluded that a low concentration of fluoride can act as a stimulator of type I collagen deposition in the extracellular matrix of dentin, while high concentrations of fluoride have an opposite effect, acting as an inhibitor of type I collagen formation in dentin.

  14. Quantification of collagen fibers in canine uteri treated with medroxyprogesterone acetate

    Directory of Open Access Journals (Sweden)

    Paulo Salinas

    Full Text Available ABSTRACT: Collagen plays essential roles in remodeling uterine tissue during decidualization, implantation, pregnancy and involution. To understand whether the progestational agent medroxyprogesterone acetate (MPA can modify the organization and deposit of collagen in the uteri of normal bitches (Canis Tlupus familiaris, we assessed uterine tissues by histochemistry. Uteri were grouped as: nulliparous (n=11, multiparous (n=11 and treated with MPA (n=11; nulliparous with two treatments; 5mg/kg; i.m.. The amount, location and birefringence of interstitial collagen types I and III in the fold and base of the endometrial stroma and the myometrial muscular layers were studied on sections stained with Picrosirius Red by polarized light microscopy and evaluated by ANOVA. No differences were observed in the endometrium. In the myometrium, differences were observed in collagen type I between MPA-treated and nulliparous uteri vs. multiparous (p<0.05, and differences in collagen type III between nulliparous and multiparous uteri vs. MPA-treated (p=0.0001. In conclusion, two doses of MPA had no significant effect on the investigated collagens in the extracellular matrix.

  15. 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.

  16. Regulation of migratory activity of human keratinocytes by topography of multiscale collagen-containing nanofibrous matrices.

    Science.gov (United States)

    Fu, Xiaoling; Xu, Meng; Liu, Jie; Qi, Yanmei; Li, Shaohua; Wang, Hongjun

    2014-02-01

    Nanofibrous matrices hold great promise in skin wound repair partially due to their capability of recapturing the essential attributes of native extracellular matrix (ECM). With regard to limited studies on the effect of nanofibrous matrices on keratinocytes, the present study was aimed to understand how the topographical feature of nanofibrous matrices regulates keratinocyte motility by culturing keratinocytes on polycaprolactone (PCL)/collagen nanofibrous matrices (rough surface with fiber diameters of 331 ± 112 nm) or the matrices coated with a thin layer of collagen gel to form a secondary ultrafine fibrous network (smooth surface with ultrafine fiber diameters of 55 ± 26 nm). It was found that the PCL/collagen nanofibrous matrices alone did not stimulate cell migration, while collagen gel coating could significantly increase cell motility. Further studies demonstrated that the ultrafine fibrous network of collagen gel coating significantly activated integrin β1, Rac1 and Cdc42, facilitated the deposition of laminin-332 (formerly called laminin-5), and promoted the expression of active matrix metalloproteinases (MMPs) (i.e., MMP-2 and 9). Neutralization of integrin β1 activity abrogated the gel coating-induced keratinocyte migration. These findings provide important evidence on the role of topographical features of nanofibrous matrices in regulating the phenotypic alteration of keratinocytes and suggest the possible utility of collagen-containing nanofibrous matrices for skin regeneration especially in re-epithelialization. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Fibrin binds to collagen and provides a bridge for αVβ3 integrin-dependent contraction of collagen gels

    Science.gov (United States)

    Reyhani, Vahid; Seddigh, Pegah; Guss, Bengt; Gustafsson, Renata; Rask, Lars; Rubin, Kristofer

    2014-01-01

    The functional significance of fibrin deposits typically seen in inflammatory lesions, carcinomas and in healing wounds is not fully understood. In the present study, we demonstrate that fibrinogen/fibrin specifically bound to native Col I (collagen type I) and used the Col I fibre network as a base to provide a functional interface matrix that connects cells to the Col I fibres through αVβ3 integrins. This allowed murine myoblast C2C12 cells to contract the collagenous composite gel via αVβ3 integrin. We show that fibrinogen specifically bound to immobilized native Col I at the site known to bind matrix metalloproteinase-1, discoidin domain receptor-2 and fibronectin, and that binding had no effect on Col I fibrillation. A specific competitive inhibitor blocking the Col-I-binding site for fibrinogen abolished the organization of fibrin into discernable fibrils, as well as the C2C12-mediated contraction of Col I gels. Our data show that fibrin can function as a linkage protein between Col I fibres and cells, and suggest that fibrin at inflammatory sites indirectly connects αVβ3 integrins to Col I fibres and thereby promotes cell-mediated contraction of collagenous tissue structures. PMID:24840544

  18. Direct detection of collagenous proteins by fluorescently labeled collagen mimetic peptides

    Science.gov (United States)

    Li, Yang; Ho, Daniel; Meng, Huan; Chan, Tania R.; An, Bo; Yu, Hanry; Brodsky, Barbara; Jun, Albert S.; Yu, S. Michael

    2013-01-01

    Although fibrous collagens are major structural components of extracellular matrix in mammals, collagen overproduction is associated with many human diseases including cancers and fibrosis. Collagen is typically identified in biomedical research by western blot and immunohistochemistry; however anti-collagen antibodies employed in these analyses are difficult to prepare and their affinities to collagen can diminish if collagen becomes denatured during analyses. Previously, we discovered that single-stranded collagen mimetic peptides [CMPs, sequence: (GlyProHyp)9] can bind to denatured collagen chains by triple helix hybridization. Here we present collagen-specific staining methods using simple CMPs conjugated to common fluorophores (e.g. carboxyfluorescein), which allow direct detection of collagens and collagen-like proteins in SDS-PAGE and in various mammalian tissue sections. By directly staining SDS-PAGE gels with fluorescently labeled CMPs, both intact (type I, II, and IV) and MMP-1 cleaved collagen (type I) chains as well as complement factor C1q were detected. Collagen bands containing as little as 5 ng were optically visualized while no staining was observed for fibronectin, laminin, and a collection of proteins from mammalian cell lysate. The CMP was unable to stain collagen-like bacterial protein which contains numerous charged amino acids that are believed to stabilize triple helix in place of Hyp. We also show that fluorescently labeled CMPs can specifically visualize collagens in fixed tissue sections (e.g., skin, cornea, and bone) more effectively than anti-collagen I antibody, and allow facile identification of pathologic conditions in fibrotic liver tissues. PMID:23253177

  19. [Peritoneal splenosis 26 years after traumatic splenic rupture--rare differential diagnosis of a subepithelial gastric mass--case report and review of the literature].

    Science.gov (United States)

    Garlipp, B; Zeh, M; Scheidbach, H; Kuester, D; Lippert, H

    2011-03-01

    Differential diagnoses of subepithelial gastric masses include benign (leiomyoma, lipoma, haemangioma, lymphangioma, neurogenic tumours, glomus tumour) and malignant (leiomyosarcoma, gastric Kaposi's sarcoma, metastases) neoplastic lesions, gastrointestinal stromal tumours (GIST) and lesions of non-neoplastic origin (heterotopic pancreatic tissue, intramural pseudocysts, intramural haematoma). Occasionally, however, suspected gastric wall tumours are caused by extragastral lesions that are not always easily distinguished from genuine gastric wall lesions by endoscopy or radiological imaging. We report the case of a 77-year-old patient undergoing laparoscopy for suspected gastric GIST in our institution in whom splenectomy had been performed 26 years prior to presentation due to traumatic splenic rupture. The tumour revealed to be ectopic splenic tissue located at the parietal peritoneum of the ventral abdominal wall, thereby fulfilling the definition of splenosis. Epidemiology, pathogenesis, diagnostics and therapy of splenosis are discussed in the context of a review of the relevant literature. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Subepithelial Connective Tissue Graft in Combination with a Tunnel Technique for the Treatment of Miller Class II and III Gingival Recessions in Mandibular Incisors: Clinical and Esthetic Results.

    Science.gov (United States)

    Nart, Jose; Valles, Cristina

    2016-01-01

    There is limited evidence regarding the effect of the subepithelial connective tissue graft (SCTG) on root coverage in the mandibular anterior region. A sample of 15 Miller Class II and III recessions were treated in 15 patients using a SCTG with a tunnel technique. After a mean follow-up of 20.53 months, the mean percentage of root coverage was 83.25% for all treated recessions. Furthermore, a statistically significant increase of keratinized tissue was observed at the end of the evaluation period (2.66 mm; P = .001). The combination of tunnel technique and SCTG should be considered a treatment option to obtain root coverage in mandibular incisors with Class II and III recession defects.

  1. Interstitial Perfusion Culture with Specific Soluble Factors Inhibits Type I Collagen Production from Human Osteoarthritic Chondrocytes in Clinical-Grade Collagen Sponges.

    Science.gov (United States)

    Mayer, Nathalie; Lopa, Silvia; Talò, Giuseppe; Lovati, Arianna B; Pasdeloup, Marielle; Riboldi, Stefania A; Moretti, Matteo; Mallein-Gerin, Frédéric

    2016-01-01

    Articular cartilage has poor healing ability and cartilage injuries often evolve to osteoarthritis. Cell-based strategies aiming to engineer cartilaginous tissue through the combination of biocompatible scaffolds and articular chondrocytes represent an alternative to standard surgical techniques. In this context, perfusion bioreactors have been introduced to enhance cellular access to oxygen and nutrients, hence overcoming the limitations of static culture and improving matrix deposition. Here, we combined an optimized cocktail of soluble factors, the BIT (BMP-2, Insulin, Thyroxin), and clinical-grade collagen sponges with a bidirectional perfusion bioreactor, namely the oscillating perfusion bioreactor (OPB), to engineer in vitro articular cartilage by human articular chondrocytes (HACs) obtained from osteoarthritic patients. After amplification, HACs were seeded and cultivated in collagen sponges either in static or dynamic conditions. Chondrocyte phenotype and the nature of the matrix synthesized by HACs were assessed using western blotting and immunohistochemistry analyses. Finally, the stability of the cartilaginous tissue produced by HACs was evaluated in vivo by subcutaneous implantation in nude mice. Our results showed that perfusion improved the distribution and quality of cartilaginous matrix deposited within the sponges, compared to static conditions. Specifically, dynamic culture in the OPB, in combination with the BIT cocktail, resulted in the homogeneous production of extracellular matrix rich in type II collagen. Remarkably, the production of type I collagen, a marker of fibrous tissues, was also inhibited, indicating that the association of the OPB with the BIT cocktail limits fibrocartilage formation, favoring the reconstruction of hyaline cartilage.

  2. Investigation on the effect of collagen and vitamins on biomimetic hydroxyapatite coating formation on titanium surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ciobanu, Gabriela, E-mail: gciobanu03@yahoo.co.uk [“Gheorghe Asachi” Technical University of Iasi, Faculty of Chemical Engineering and Environmental Protection, Prof. dr. docent Dimitrie Mangeron Rd., no. 63, zip: 700050, Iasi (Romania); Ciobanu, Octavian [“Grigore T. Popa” University of Medicine and Pharmacy, Faculty of Medical Bioengineering, Universitatii Str., no. 16, zip: 700115, Iasi (Romania)

    2013-04-01

    This study uses an in vitro experimental approach to investigate the roles of collagen and vitamins in regulating the deposition of hydroxyapatite layer on the pure titanium surface. Titanium implants were coated with a hydroxyapatite layer under biomimetic conditions by using a supersaturated calcification solution (SCS), modified by adding vitamins A and D{sub 3}, and collagen. The hydroxyapatite deposits on titanium were investigated by means of scanning electron microscopy (SEM) coupled with X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy. The results obtained have shown that hydroxyapatite coatings were produced in vitro under vitamins and collagen influence. - Highlights: ► Hydroxyapatite was grown on Ti using a modified supersaturated calcification solution (M-SCS). ► Vitamins (A and D3) and collagen in M-SCS have a significant effect on apatite precipitation. ► M-SCS stimulates a biomimetic apatite deposition with 0.5–1 μm thickness in a short time. ► Hydroxyapatite crystallites have thin plate morphologies and size below 1 μm.

  3. Lysyl oxidase interacts with AGE signalling to modulate collagen synthesis in polycystic ovarian tissue.

    Science.gov (United States)

    Papachroni, Katerina K; Piperi, Christina; Levidou, Georgia; Korkolopoulou, Penelope; Pawelczyk, Leszek; Diamanti-Kandarakis, Evanthia; Papavassiliou, Athanasios G

    2010-10-01

    Connective tissue components--collagen types I, III and IV--surrounding the ovarian follicles undergo drastic changes during ovulation. Abnormal collagen synthesis and increased volume and density of ovarian stroma characterize the polycystic ovary syndrome (PCOS). During the ovulatory process, collagen synthesis is regulated by prolyl hydroxylase and lysyl oxidase (LOX) activity in ovarian follicles. LOX catalyzes collagen and elastin cross-linking and plays essential role in coordinating the control of ovarian extracellular matrix (ECM) during follicular development. We have recently shown accumulation of advanced glycation end products (AGEs), molecules that stimulate ECM production and abnormal collagen cross-linking, in ovarian tissue. However, the possible link between LOX and AGEs-induced signalling in collagen production and stroma formation in ovarian tissue from PCOS remains elusive. The present study investigates the hypothesis of AGE signalling pathway interaction with LOX gene activity in polycystic ovarian (PCO) tissue. We show an increased distribution and co-localization of LOX, collagen type IV and AGE molecules in the PCO tissue compared to control, as well as augmented expression of AGE signalling mediators/effectors, phospho(p)-ERK, phospho(p)-c-Jun and nuclear factor κB (NF-κB) in pathological tissue. Moreover, we demonstrate binding of AGE-induced transcription factors, NF-κB and activator protein-1 (AP-1) on LOX promoter, indicating a possible involvement of AGEs in LOX gene regulation, which may account for the documented increase in LOX mRNA and protein levels compared to control. These findings suggest that deposition of excess collagen in PCO tissue that induces cystogenesis may, in part, be due to AGE-mediated stimulation of LOX activity. © 2009 The Authors Journal compilation © 2010 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

  4. 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.

  5. Genetics Home Reference: collagen VI-related myopathy

    Science.gov (United States)

    ... Twitter Home Health Conditions Collagen VI-related myopathy Collagen VI-related myopathy Printable PDF Open All Close ... Javascript to view the expand/collapse boxes. Description Collagen VI-related myopathy is a group of disorders ...

  6. Dimensional Changes of Collagen: with thermo mechanical stress

    Indian Academy of Sciences (India)

    Thermo gram of collagen displays multiples of heat inducted transitions and relaxation of collagen fibers exhibit multiple processes. Multiplicity of pressure and temperature induced processes offers special attributes for the use of collagen as a biomaterial.

  7. Collagen gene interactions and endurance running performance

    African Journals Online (AJOL)

    Furthermore, variants within the COL5A1 3'-UTR, including rs12722, are proposed to alter the expression of type V collagen, thereby modulating normal fibrillogenesis and resulting in changes to the collagen fibril architecture, structure and mechanical properties. [9] Simi- larly, COL6A1 rs35796750 is proposed to result in ...

  8. The collagens of the developing bovine cornea.

    Science.gov (United States)

    Lee, R E; Davison, P F

    1984-11-01

    The morphology of the developing bovine eye has been examined and the collagens in fetal bovine eyes from three months' gestation to maturity have been solubilized by pepsin treatment and analyzed to determine the ratios of the predominant types of collagen. The type I collagen decreased, while the type V collagen increased with age. Type III collagen comprised less than 1% of all the corneas, except for the three-month fetal calf. The anterior to posterior thickness of the paraffin-embedded fetal calf cornea increased from the third to the seventh month, decreased from the seventh month to birth, and then increased after birth. Descemet's membrane increased in thickness with age. Analysis of dissected regions of the calf cornea showed a uniform distribution of the collagen populations from the center to the limbus (89% type I, 10% type V and less than 1% type III collagen) and uniformity through the depth of the stroma, except that type III was concentrated around Bowman's layer, and type IV in Descement's membrane. The localization of the different collagens was consistent with the immunofluorescent staining studies with anticollagen antibodies, but the ratios of the intensities of the fluorescence did not correspond to the quantitative analyses. These results are concordant with other studies that have shown that antibody binding may be masked or diminished in certain tissues and therefore immunofluorescence cannot be used reliably for quantitative measurements.

  9. A novel benign solution for collagen processing

    Science.gov (United States)

    Arnoult, Olivier

    Collagen is the main protein constituting the extracellular matrix (ECM) of tissues in the body (skin, cartilage, blood vessels...). It exists many types of collagen, this work studies only fibrillar collagen (e.g. collagen type I contained in the skin) that exhibits a triple helical structure composed of 3 alpha-helical collagen chains. This particular and defined hierarchical structure is essential to the biological and mechanical properties of the collagen. Processing collagen into scaffolds to mimic the ECM is crucial for successful tissue engineering. Recently collagen was processed into fibrous and porous scaffold using electrospinning process. However the solvent (HFIP) used for electrospinning is extremely toxic for the user and expensive. This work shows that HFIP can be replaced by a benign mixture composed of water, salt and alcohol. Yet only three alcohols (methanol, ethanol and iso-propanol) enable the dissolution of large quantity of collagen in the benign mixture, with a wide range of alcohol to buffer ratio, and conserve the collagen hierarchical structure at least as well as the HFIP. Collagen can be electrospun from the benign mixture into sub-micron fibers with concentrations as low as 6 wt-% for a wide range of alcohol to buffer ratio, with at least 10wt-% of salt, and any of the three alcohols. Specific conditions yield nano size fibers. After processing from HFIP or a benign mixture, collagen is water soluble and needs to be chemically crosslink for tissue engineering application. Post-crosslinking with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) results in the loss of the scaffold fibrous aspect and porosity, hence it is useless for tissue engineering. Such issue could be prevented by incorporating the crosslinker into the mixture prior to electrospinning. When EDC is used alone, collagen forms a gel in the mixture within minutes, preventing electrospinning. The addition of N-hydroxysuccinimide (NHS) in excess to EDC

  10. Collagen types I, III, and V constitute the thick collagen fibrils of the mouse decidua.

    Science.gov (United States)

    Spiess, Karin; Zorn, Telma Maria Tenório

    2007-01-01

    A mammal's endometrium is deeply remodeled while receiving and implanting an embryo. In addition to cell proliferation and growth, endometrial remodeling also comprises synthesis and degradation of several molecular components of the extracellular matrix. All of these events are orchestrated by a precise sequence of ovarian hormones and influenced by several types of cytokines. As we have previously reported, an intriguing and rapid increase in collagen fibril diameter occurs in the decidualized areas of the endometrium, surrounding the implantation crypt, whereas collagen fibrils situated far from the embryo remain unchanged. Collagen fibrilogenesis is a complex molecular process coordinated by a number of factors, such as the types and amounts of glycosaminoglycans and proteoglycans associated with collagen molecules. Collagen genetic type, mechanical stress, aging, and other factors not yet identified also contribute to this development. A recent study suggests that thick fibrils from mouse decidua are formed, at least in part, by aggregation of thin fibrils existing in the stroma before the onset of decidualization. In the present ultrastructural study using single and double immunogold localization, we showed that both thin and thick collagen fibrils present in the mouse pregnant endometrium endometrium are heterotypic structures formed at least by type I, type III, and type V collagens. However, type V collagen predominates in the thick collagen fibrils, whereas it is almost absent of the thin collagen fibrils. The putative role of type V homotrimer in the rapid increase of the diameter of collagen fibrils of the mouse decidua is discussed.

  11. 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...

  12. Bioengineered collagens: emerging directions for biomedical materials.

    Science.gov (United States)

    Ramshaw, John A M; Werkmeister, Jerome A; Dumsday, Geoff J

    2014-01-01

    Mammalian collagen has been widely used as a biomedical material. Nevertheless, there are still concerns about the variability between preparations, particularly with the possibility that the products may transmit animal-based diseases. Many groups have examined the possible application of bioengineered mammalian collagens. However, translating laboratory studies into large-scale manufacturing has often proved difficult, although certain yeast and plant systems seem effective. Production of full-length mammalian collagens, with the required secondary modification to give proline hydroxylation, has proved difficult in E. coli. However, recently, a new group of collagens, which have the characteristic triple helical structure of collagen, has been identified in bacteria. These proteins are stable without the need for hydroxyproline and are able to be produced and purified from E. coli in high yield. Initial studies indicate that they would be suitable for biomedical applications.

  13. Laser-assisted subepithelial keratectomy (LASEK) versus laser-assisted in-situ keratomileusis (LASIK) for correcting myopia.

    Science.gov (United States)

    Kuryan, Jocelyn; Cheema, Anjum; Chuck, Roy S

    2017-02-15

    Near-sightedness, or myopia, is a condition in which light rays entering the eye along the visual axis focus in front of the retina, resulting in blurred vision. Myopia can be treated with spectacles, contact lenses, or refractive surgery. Options for refractive surgery include laser-assisted subepithelial keratectomy (LASEK) and laser-assisted in-situ keratomileusis (LASIK). Both procedures utilize a laser to shape the corneal tissue (front of the eye) to correct refractive error, and both create flaps before laser treatment of corneal stromal tissue. Whereas the flap in LASEK is more superficial and epithelial, in LASIK it is thicker and also includes some anterior stromal tissue. LASEK is considered a surface ablation procedure, much like its predecessor, photorefractive keratectomy (PRK). LASEK was developed as an alternative to PRK to address the issue of pain associated with epithelial debridement used for PRK. Assessing the relative benefits and risks/side effects of LASEK and LASIK warrants a systematic review. To assess the effects of LASEK versus LASIK for correcting myopia. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Trials Register (2016, Issue 10); MEDLINE Ovid (1946 to 24 October 2016); Embase.com (1947 to 24 October 2016); PubMed (1948 to 24 October 2016); LILACS (Latin American and Caribbean Health Sciences Literature Database; 1982 to 24 October 2016); the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), last searched 20 June 2014; ClinicalTrials.gov (www.clinicaltrials.gov); searched 24 October 2016; and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 24 October 2016. We did not use any date or language restrictions in the electronic searches for trials. We considered only randomized controlled trials (RCTs) for the purposes of this review. Eligible RCTs were those in which myopic participants were

  14. 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

  15. Effect of nicotinamide on amino acids content in bone collagen depending on biological availability of vitamins in diabetic rats.

    Science.gov (United States)

    Guzyk, M M; Sergiichuk, Iu T; Dyakun, K O; Yanitska, L V; Kuchmerovska, T M

    2014-01-01

    Connective tissue is highly susceptible to imbalances induced by diabetes. Diabetes-related osteopenia, decreased bone strength etc. may be associated with altered metabolism of various collagens: Although it is assumed that alterations in collagen amino acids (AA) may strongly affect protein properties andphysiological functions, however, very limited evidences are present at the moment regarding AA composition of bone type I collagen and its relevance to abnormal availability of vitamins which are necessary for collagen synthesis in diabetes. We have tested whether nicotinamide (NAm) can influence type Icollagen formation and AA composition as well as vitamins availability in diabetes. After 4 weeks of STZ-induced diabetes (60 mg/ kg) male Wistar rats were injected for 2 weeks with/without NAm (200 mg/kg b. w). Acid extraction of type I collagen from the bones was performed with following stepwise salting out. The content of type I collagen after its acid extraction from the bones was estimated by the amounts of hydroxyproline. Amino acids were assayed by cation exchange chromatography Diabetes-associated changes in AA composition of type I collagen mainly affect those amino acids which are known to be involved in helix formation and cross-linking of the molecules. Diabetes was found to significantly reduce bone collagen contents of o-Pro, Gly, Ala, o-Lys and Pro, whereas Lys, His, Arg, Glu, Thr, Leu, Phe contents were elevated (P vitamin C and B3 contents were shown to be significantly lowered, whereas a-tocopherol was slightly increased compared with control (P vitamin C and B3 was observed. The data demonstrate the close relationship between the diabetes-associated decrease in type I collagen deposition, altered amino acids metabolism and impaired availability of vitamins, which are necessary for collagen synthesis. Thus, NAm might be a useful agent for treatment of bone failures related to diabetes.

  16. Proportion of types I and III collagen in longissimus collagen from bulls and steers.

    Science.gov (United States)

    Burson, D E; Hunt, M C; Unruh, J A; Dikeman, M E

    1986-08-01

    The proportion of types I and III intramuscular collagen in longissimus muscles of Simmental bulls (n = 8) and steers (n = 8) 17 mo of age was studied. Longissimus samples taken 7 d after slaughter were evaluated for total collagen, types I and III collagen, heat-soluble collagen, sensory panel traits and Warner-Bratzler shear force. Intramuscular collagen (IMC) was isolated and digested with cyanogen bromide, and peptides were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Percentage of type III IMC was calculated from the total of types I and III collagen as determined from the peak area of densitometric scans of the cyanogen bromide peptides alpha 1(I)CB8 and alpha 1(III)CB8. Longissimus muscles from steers had lower (P less than .05) Warner-Bratzler shear values, less (P less than .05) sensory panel-detectable connective tissue and more (P less than .05) tender panel ratings for muscle fiber tenderness and overall tenderness. Muscles from steers had more (P less than .05) heat-soluble collagen than those from bulls, but no differences (P greater than .05) were found for total collagen and percentage of type III collagen. Some intramuscular-collagen characteristics may have contributed to the less tender muscle of bulls. However, the proportion of types I and III collagen did not account entirely for the tenderness difference between steer and bull muscles. Because there were differences in collagen solubility in muscles from steers and bulls, other collagen characteristics such as crosslinking or fiber size may have been more important than collagen type.

  17. Collagen fibrillogenesis in vitro: interaction of types I and V collagen regulates fibril diameter.

    Science.gov (United States)

    Birk, D E; Fitch, J M; Babiarz, J P; Doane, K J; Linsenmayer, T F

    1990-04-01

    The small-diameter fibrils of the chick corneal stroma are heterotypic, composed of both collagen types I and V. This tissue has a high concentration of type V collagen relative to other type I-containing tissues with larger-diameter fibrils, suggesting that heterotypic interactions may have a regulatory role in the control of fibril diameter. The interactions of collagen types I and V were studied using an in vitro self-assembly system. Collagens were purified from lathyritic chick embryos in the presence of protease inhibitors. The type V collagen preparations contained higher molecular weight forms of the alpha 1(V) and alpha 2(V) chains constituting 60-70% of the total. Rotary-shadow electron micrographs showed a persistence of a small, pepsin-sensitive terminal region in an amount consistent with that seen by electrophoresis. In vitro, this purified type V collagen formed thin fibrils with no apparent periodicity, while type I collagen fibrils had a broad distribution of large diameters. However, when type I collagen was mixed with increasing amounts of type V collagen a progressive and significant decrease in both the mean fibril diameter and the variance was observed for D periodic fibrils. The amino-terminal domain of the type V collagen molecule was required for this regulatory effect and in its absence little diameter reducing activity was observed. Electron microscopy using collagen type-specific monoclonal antibodies demonstrated that the fibrils formed were heterotypic, containing both collagen types I and V. These data indicate that the interaction of type V with type I collagen is one mechanism modulating fibril diameter and is at least partially responsible for the regulation of collagen fibril formation.

  18. Resorbable collagen membranes: histopathologic features.

    Science.gov (United States)

    Almazrooa, Soulafa A; Noonan, Vikki; Woo, Sook-Bin

    2014-08-01

    Resorbable collagen membranes (RCMs) are commonly used by oral surgeons, periodontists, and endodontists for multiple purposes. We report 6 cases of RCMs that did not resorb as expected and describe the histopathologic features. Cases of an unusual fibrillar foreign material were noted in biopsy specimens curetted from bone. Hematoxylin-eosin and Masson trichrome stains were performed. Clinicians were contacted for detailed clinical information. There were 3 men and 3 women. RCMs presented as hyalinized, paucicellular, delicate eosinophilic fibrils or a meshwork without a foreign body reaction. They were refractile and stained for Masson trichrome as expected. These RCMs persisted longer than expected (2-6 weeks) in 3 cases and may have retarded healing in 5 cases. Although RCM is supposed to be fairly rapidly resorbable, this material sometimes persists within wound sites without any obvious foreign body reaction and may retard healing. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Microscopic distribution patterns of microspheres deposited by inhalation in lungs of rats, guinea pigs, and dogs

    Energy Technology Data Exchange (ETDEWEB)

    Snipes, M.B.; Guilmette, R.A.; Nikula, K.J.

    1995-12-01

    Acute inhalation exposures of mammalian species to small amounts of poorly soluble particles result in deposition of the particles in the head airways, tracheobronchial region, and pulmonary region of the respiratory tract. Most of the particles that deposit in the head airways and tracheobronchial region are believed to clear rapidly, but some as yet undefined fraction of the particles is retained in the airway epithelium or subepithelial interstitium for extended times. This long-term retention has important implications for the new respiratory tract dosimetry model of the International Commission on Radiological Protection because particles retained within the region can result in long-term exposure of airway epithelial cells. Preliminary results from this study demonstrate that a substantial fraction of the PSL microspheres inhaled by these rats, guinea pigs, and dogs was incorporated into the epithelium and interstitium of the tracheobronchial region.

  20. 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.

  1. The Mineral–Collagen Interface in Bone

    Science.gov (United States)

    2015-01-01

    The interface between collagen and the mineral reinforcement phase, carbonated hydroxyapatite (cAp), is essential for bone’s remarkable functionality as a biological composite material. The very small dimensions of the cAp phase and the disparate natures of the reinforcement and matrix are essential to the material’s performance but also complicate study of this interface. This article summarizes what is known about the cAp-collagen interface in bone and begins with descriptions of the matrix and reinforcement roles in composites, of the phases bounding the interface, of growth of cAp growing within the collagen matrix, and of the effect of intra- and extrafibrilar mineral on determinations of interfacial properties. Different observed interfacial interactions with cAp (collagen, water, non-collagenous proteins) are reviewed; experimental results on interface interactions during loading are reported as are their influence on macroscopic mechanical properties; conclusions of numerical modeling of interfacial interactions are also presented. The data suggest interfacial interlocking (bending of collagen molecules around cAp nanoplatelets) and water-mediated bonding between collagen and cAp are essential to load transfer. The review concludes with descriptions of areas where new research is needed to improve understanding of how the interface functions. PMID:25824581

  2. 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.

  3. 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.

  4. Bioglass incorporation improves mechanical properties and enhances cell-mediated mineralization on electrochemically aligned collagen threads.

    Science.gov (United States)

    Nijsure, Madhura P; Pastakia, Meet; Spano, Joseph; Fenn, Michael B; Kishore, Vipuil

    2017-09-01

    Bone tissue engineering mandates the development of a functional scaffold that mimics the physicochemical properties of native bone. Bioglass 45S5 (BG) is a highly bioactive material known to augment bone formation and restoration. Hybrid scaffolds fabricated using collagen type I and BG resemble the organic and inorganic composition of the bone extracellular matrix and hence have been extensively investigated for bone tissue engineering applications. However, collagen-BG scaffolds developed thus far do not recapitulate the aligned structure of collagen found in native bone. In this study, an electrochemical fabrication method was employed to synthesize BG-incorporated electrochemically aligned collagen (BG-ELAC) threads that are compositionally similar to native bone. Further, aligned collagen fibrils within BG-ELAC threads mimic the anisotropic arrangement of collagen fibrils in native bone. The effect of BG incorporation on the mechanical properties and cell-mediated mineralization on ELAC threads was investigated. The results indicated that BG can be successfully incorporated within ELAC threads, without disturbing collagen fibril alignment. Further, BG incorporation significantly increased the ultimate tensile stress (UTS) and modulus of ELAC threads (p < 0.05). SBF conditioning showed extensive mineralization on BG-ELAC threads that increased over time demonstrating the bone bioactivity of BG-ELAC threads. Additionally, BG incorporation into ELAC threads resulted in increased cell proliferation (p < 0.05) and deposition of a highly dense and continuous mineralized matrix. In conclusion, incorporation of BG into ELAC threads is a viable strategy for the development of an osteoconductive material for bone tissue engineering applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2429-2440, 2017. © 2017 Wiley Periodicals, Inc.

  5. Stromal assemblies containing collagen types IV and VI and fibronectin in the developing embryonic avian cornea.

    Science.gov (United States)

    Fitch, J M; Birk, D E; Linsenmayer, C; Linsenmayer, T F

    1991-04-01

    The morphogenesis of type IV collagen-containing structures in the stromal matrix of the developing avian cornea was investigated using immunofluorescence and immunoelectron microscopic histochemistry. Two forms of type IV collagen-containing structures were seen; these differed in their probable origin, structure, molecular composition, and developmental fate. The major form of stromal type IV collagen-containing material, termed "strings," was observed only after swelling of the primary stroma and the onset of mesenchymal invasion. These strings are presumed to be products of the stromal cells. In immunofluorescence histochemistry they appeared as linear segments of type IV collagen-specific immunoreactivity. In immunoelectron microscopy, they appeared initially as electron-dense sausages of variable length and orientation. They frequently were associated with cell surfaces and, in fortuitous sections, appeared to connect adjacent cells. The strings also contained type VI collagen and fibronectin, but very little, if any, of the basement membrane components laminin and heparin sulfate proteoglycan (HSPG). As the stroma continued to expand in thickness, more of these structures were observed in a radial orientation, becoming quite long and less tortuous. Later in development, as stromal condensation proceeded, they disappeared. We suggest that the strings function to stabilize the stromal matrix, and perhaps to limit the rate and/or extent of stromal expansion, during a phase of rapid swelling and matrix deposition. The other form of type IV collagen-containing stromal material appeared as irregularly shaped plaques of basement membrane-like material identical to those previously described in mature corneas. These are likely derived from the corneal endothelial cells. They contained other basement membrane-associated components (laminin, HSPG) and fibronectin, but not type VI collagen. This material persists in mature corneas as sparse irregular stromal plaques

  6. Collagen plug occlusion of Molteno tube shunts.

    Science.gov (United States)

    Stewart, W; Feldman, R M; Gross, R L

    1993-01-01

    We report five patients in whom collagen lacrimal plugs were used to temporarily occlude the lumen of Molteno shunts to prevent early postoperative hypotony. Only one eye, with a double plate, developed hypotony and a flat anterior chamber that required reformation. However, in three patients, the collagen plugs did not dissolve and had to be removed surgically to lower the intraocular pressure. Although the semipermeability of collagen is desirable, its unpredictable degradation renders it unsuitable for temporary occlusion of tube shunts. Other biodegradable materials may be more appropriate for this purpose.

  7. A modified elliptical formula to estimate kidney collagen content in a model of chronic kidney disease.

    Science.gov (United States)

    Nieto, Jake A; Zhu, Janice; Duan, Bin; Li, Jingsong; Zhou, Ping; Paka, Latha; Yamin, Michael A; Goldberg, Itzhak D; Narayan, Prakash

    2018-01-01

    The extent of scarring or renal interstitial collagen deposition in chronic kidney disease (CKD) can only be ascertained by highly invasive, painful and sometimes risky, tissue biopsy. Interestingly, while CKD-related abnormalities in kidney size can often be visualized using ultrasound, not only does the ellipsoid formula used today underestimate true renal size, but the calculated renal size does not inform tubulointerstitial collagen content. We used coronal kidney sections from healthy mice and mice with kidney disease to develop a new formula for estimating renal parenchymal area. While treating the kidney as an ellipse with the major axis (a) the polar distance, this technique involves extending the minor axis (b) into the renal pelvis to obtain a new minor axis, be. The calculated renal parenchymal area is remarkably similar to the true or measured area. Biochemically determined kidney collagen content revealed a strong and positive correlation with the calculated renal parenchymal area. Picrosirius red staining for tubulointerstitial collagen also correlated with calculated renal parenchymal area. The extent of renal scarring, i.e. kidney interstitial collagen content, can now be computed by making just two axial measurements which can easily be accomplished via noninvasive imaging of this organ.

  8. Utility of an optically-based, micromechanical system for printing collagen fibers

    Science.gov (United States)

    Paten, Jeffrey A.; Tilburey, Graham E.; Molloy, Eileen A.; Zareian, Ramin; Trainor, Christopher V.

    2013-01-01

    Collagen's success as the principal structural element in load-bearing, connective tissue has motivated the development of numerous engineering approaches designed to recapitulate native fibril morphology and strength. It has been shown recently that collagen fibers can be drawn from monomeric solution through a fiber forming buffer (FFB), followed by numerous additional treatments in a complex serial process. However, internal fibril alignment, packing and resultant mechanical behavior of the fibers have not been optimized and remain inferior to native tissue. Further, no system has been developed which permits simultaneous application of molecular crowding, measurement of applied load, and direct observation of polymerization dynamics during fiber printing. The ability to perform well-controlled investigations early in the process of fiber formation, which vary single input parameters (i.e. collagen concentration, crowding agent concentration, draw rate, flow rate, temperature, pH, etc.) should substantially improve fiber morphology and strength. We have thus designed, built, and tested a versatile, in situ, optically-based, micromechanical assay and fiber printing system which permits the correlation of parameter changes with mechanical properties of fibers immediately after deposition into an FFB. We demonstrate the sensitivity of the assay by detecting changes in the fiber mechanics in response to draw rate, collagen type, small changes in the molecular crowding agent concentration and to variations in pH. In addition we found the ability to observe fiber polymerization dynamics leads to intriguing new insights into collagen assembly behavior. PMID:23352045

  9. Collagen Matrix Density Drives the Metabolic Shift in Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Brett A. Morris

    2016-11-01

    Full Text Available Increased breast density attributed to collagen I deposition is associated with a 4–6 fold increased risk of developing breast cancer. Here, we assessed cellular metabolic reprogramming of mammary carcinoma cells in response to increased collagen matrix density using an in vitro 3D model. Our initial observations demonstrated changes in functional metabolism in both normal mammary epithelial cells and mammary carcinoma cells in response to changes in matrix density. Further, mammary carcinoma cells grown in high density collagen matrices displayed decreased oxygen consumption and glucose metabolism via the tricarboxylic acid (TCA cycle compared to cells cultured in low density matrices. Despite decreased glucose entry into the TCA cycle, levels of glucose uptake, cell viability, and ROS were not different between high and low density matrices. Interestingly, under high density conditions the contribution of glutamine as a fuel source to drive the TCA cycle was significantly enhanced. These alterations in functional metabolism mirrored significant changes in the expression of metabolic genes involved in glycolysis, oxidative phosphorylation, and the serine synthesis pathway. This study highlights the broad importance of the collagen microenvironment to cellular expression profiles, and shows that changes in density of the collagen microenvironment can modulate metabolic shifts of cancer cells.

  10. 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

  11. 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...

  12. The comparison of modified semilunar technique in conjunction with connective tissue and subepithelial connective tissue graft for root coverage: a randomized controlled trial.

    Science.gov (United States)

    Jenabian, Niloofar; Khanjani, Nafiseh; Bijani, Ali

    2017-02-01

    Gingival recession may result in aesthetically unfavourable effects, difficulty in plaque control, increased susceptibility to root caries, and dentin hypersensitivity. The aim of this study was to compare the use of modified semilunar techniques with connective tissue and subepithelial connective tissue grafts (Langer) for denuded root surface coverage. In this randomized clinical trial, fourteen localized recessions of Miller class I to II were treated in 5 subjects. Recessions were randomly treated with modified semilunar techniques (test group) and a subepithelial connective tissue graft (control group). Clinical parameters such as clinical attachment level (CAL), keratinized tissue width (KTW), probing pocket depth (PPD), vertical recession depth (VRD) and recession width (RW)were recorded at base line, 1, 3 and 6 months after surgery and healing index and the subject's satisfaction was evaluated. The repeated measure test and paired-sample t-test were used for statistical analyses by SPSS. Both methods showed significant improvement in clinical parameters. The healing index (HI) in the test group was a slightly more than the control group in Day 10. Aesthetic VAS (Visual Analogue Scale) levels in the test group were more than the control group in 1, 3 and 6 months (test group, in 1 month 6.57±1.13, in 3 month 7.86±1.07, in 6 month 8.00±0.81. control group in 1 month 5.57±1.13, in 3 month 7.00±1.00, in 6 month 7.14±0.90). The KTW, CAL, VRD and RW level's difference in the test and control group was significant in 6 month compared to the base line (p=0.000). The present study shows that treatment of Miller Class I and II gingival recession by the modified semilunar technique is acceptable. The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the Irct ID: IRCT201512021760N43. Date registered: December 27, 2015. The authors received no financial support for the research, authorship, and/or publication of this article.

  13. Type III collagen can be present on banded collagen fibrils regardless of fibril diameter

    OpenAIRE

    1987-01-01

    Monoclonal antibodies that recognize an epitope within the triple helix of type III collagen have been used to examine the distribution of that collagen type in human skin, cornea, amnion, aorta, and tendon. Ultrastructural examination of those tissues indicates antibody binding to collagen fibrils in skin, amnion, aorta, and tendon regardless of the diameter of the fibril. The antibody distribution is unchanged with donor age, site of biopsy, or region of tissue examined. In contrast, antibo...

  14. A continuum mechanics framework and a constitutive model for remodelling of collagen gels and collagenous tissues

    Science.gov (United States)

    Kroon, Martin

    2010-06-01

    Collagen is a very important protein of the human body and is responsible for the structural stability of many body components. Furthermore, collagen fibre networks are able to grow and remodel themselves, which enables them to adjust to varying physiological conditions. This remodelling is accomplished by fibre-producing cells, such as fibroblasts. The ability to adjust to new physiological conditions is very important, for example in wound healing. In the present paper, a theoretical framework for modelling collagenous tissues and collagen gels is proposed. Continuum mechanics is employed to describe the kinematics of the collagen, and affine deformations of fibres are assumed. Biological soft tissues can be approximated as being hyperelastic, and the constitutive model for the collagen fabric is therefore formulated in terms of a strain energy function. This strain energy function includes a density function that describes the distribution of the collagen fibre orientation. The density function evolves according to an evolution law, where fibres tend to reorient towards the direction of maximum Cauchy stress. The remodelling of the collagen network is also assumed to include a pre-stretching of collagen fibres, accomplished by fibroblasts. The theoretical framework is applied to experiments performed on collagen gels, where gels were exposed to remodelling under both biaxial and uniaxial constraints. The proposed model was able to predict both the resulting collagen distribution and the resulting stress-strain relationships obtained for the remodelled collagen gels. The influence of the most important model parameters is demonstrated, and it appears that there is a fairly unique set of model parameters that gives an optimal fit to the experimental data.

  15. Collagen based Biomaterials from CLRI: An Inspiration from the ...

    Indian Academy of Sciences (India)

    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. What followed later is history. Triple helical structure of collagen was reported on 7 August 1954. A tall scientific contribution emerged ...

  16. Mechanical connections between elastin and collagen.

    Science.gov (United States)

    Brown, R E; Butler, J P; Rogers, R A; Leith, D E

    1994-01-01

    The ligament supporting the leading edge of birds' wings is a connective tissue structure with unusual morphologic and elastic features. Its center section is made of a highly extensible composite of elastin and collagen fibers and its two end sections of nearly inextensible pure collagen; these are joined end-to-end in short interdigitating junctions. Substantial forces are transmitted through the junctions showing that collagen and elastin are mechanically connected. The junctions and elastic segment are sufficiently strong that when the intact ligament is maximally strained, the point of failure is commonly in the collagenous segments or their attachments to the tissues of origin or insertion. Here we outline the morphology and describe static force-length properties of this ligament.

  17. The minor collagens in articular cartilage

    DEFF Research Database (Denmark)

    Luo, Yunyun

    2017-01-01

    Articular cartilage is a connective tissue consisting of a specialized extracellular matrix (ECM) that dominates the bulk of its wet and dry weight. Type II collagen and aggrecan are the main ECM proteins in cartilage. However, little attention has been paid to less abundant molecular components......, 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...... 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...

  18. 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.

  19. 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.

  20. 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.

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

    Science.gov (United States)

    Babu, Harsha Mysore; Gujjari, Sheela Kumar; Prasad, Deepak; Sehgal, Praveen Kumar; Srinivasan, Aishwarya

    2011-01-01

    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. PMID:22368359

  2. Correlating rheological properties and printability of collagen bioinks: the effects of riboflavin photocrosslinking and pH.

    Science.gov (United States)

    Diamantides, Nicole; Wang, Louis; Pruiksma, Tylar; Siemiatkoski, Joseph; Dugopolski, Caroline; Shortkroff, Sonya; Kennedy, Stephen; Bonassar, Lawrence J

    2017-07-05

    Collagen has shown promise as a bioink for extrusion-based bioprinting, but further development of new collagen bioink formulations is necessary to improve their printability. Screening these formulations by measuring print accuracy is a costly and time consuming process. We hypothesized that rheological properties of the bioink before, during, and/or after gelation can be used to predict printability. In this study, we investigated the effects of riboflavin photocrosslinking and pH on type I collagen bioink rheology before, during, and after gelation and directly correlated these findings to the printability of each bioink formulation. From the riboflavin crosslinking study, results showed that riboflavin crosslinking increased the storage moduli of collagen bioinks, but the degree of improvement was less pronounced at higher collagen concentrations. Dots printed with collagen bioinks with riboflavin crosslinking exhibited smaller dot footprint areas than those printed with collagen bioinks without riboflavin crosslinking. From the pH study, results showed that gelation kinetics and final gel moduli were highly pH dependent and both exhibited maxima around pH 8. The shape fidelity of printed lines was highest at pH 8-9.5. The effect of riboflavin crosslinking and pH on cell viability was assessed using bovine chondrocytes. Cell viability in collagen gels was found to decrease after blue light activated riboflavin crosslinking but was not affected by pH. Correlations between rheological parameters and printability showed that the modulus associated with the bioink immediately after extrusion and before deposition was the best predictor of bioink printability. These findings will allow for the more rapid screening of collagen bioink formulations.

  3. Immunohistochemical investigation of alpha1 (IV) and alpha5 (IV) collagen chains in a broad spectrum of melanocytic tumours.

    Science.gov (United States)

    Quatresooz, Pascale; Piérard, Gérald E

    2005-06-01

    Cells of melanocytic naevi and cutaneous malignant melanomas (MM) are surrounded by a basement membrane (BM). To scrutinize any difference between the deposits of alpha1 (IV) and alpha5 (IV) collagen chains in melanocytic naevi and MM. A total of 27 common melanocytic naevi, 11 dysplastic naevi, 21 atypical naevi (melanocytomas) including Spitz and non-Spitz types, as well as 24 MM were studied. Their phenotypic and functional characteristics defined by immunohistochemistry using a panel of antibodies, including those directed to the alpha1 (IV), alpha3 (IV) and alpha5 (IV) collagen chains. Almost all naevi and half the melanocytomas exhibited a strong positivity for the alpha1 (IV) collagen chain. By contrast, the remaining melanocytomas and MM presented a heterogeneous staining pattern for the alpha1 (IV) collagen chain. One third of the naevi, 23% of the MM without cutaneous micrometastasis and 83% of MM with cutaneous micrometastasis showed discrete cytoplasmic positivity for the alpha5 (IV) collagen chain. All other melanocytic tumours were negative for this antibody. Rare MM cells in transepidermal migration were stained with the anti-alpha1 (IV) or alpha5 (IV) collagen chain antibodies. No immunoreactivity for the alpha3 (IV) collagen chain was disclosed in any of the samples. We report the expression of alpha1 (IV) and alpha5 (IV) collagen chains in naevi and MM. The inconsistent staining pattern for alpha1 (IV) collagen chain in phenotypically atypical melanocytomas and in MM highlight the heterogeneity in both cell differentiation and stroma-tumour interactions. This biological aspect may be related to neoplastic progression and influence metastatic potential.

  4. 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).

  5. Interactions between bovine cornea proteoglycans and collagen.

    OpenAIRE

    Speziale, P.; Bardoni, A; Balduini, C.

    1980-01-01

    Two types of proteoglycan subunits were obtained from bovine cornea, the first mainly composed of proteochondroitin sulphate and the second of proteokeratan sulphate. These two fractions can be obtained from the tissue as an aggregate, and are able to recombine each other after separation, to re-form the original structure. In order to investigate collagen-proteoglycan interactions, type-I collagen was isolated from bovine cornea by pepsin digestion followed by 3.5% (w/v) NaCl precipitation, ...

  6. 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.

  7. Imaging Prostate Cancer Microenvironment by Collagen Hybridization

    Science.gov (United States)

    2016-10-01

    transconjugated dye-labeled serum proteins . 13   Future Plans The PCa imaging in animal model was mainly conducted in the lab of Dr. Pomper at the Johns...the dye can transfer from CMP onto serum proteins (e.g. albumin) resulting in an unexpected drop in signal during serum stability assays and off...specifically target digested collagens with unfolded and partially denatured collagen triple helices. 2. Demonstration of ex vivo and in vivo targeting

  8. Crosslinking of collagen gels by transglutaminase.

    Science.gov (United States)

    Orban, Janine M; Wilson, Lorri B; Kofroth, Jessica A; El-Kurdi, Mohammed S; Maul, Timothy M; Vorp, David A

    2004-03-15

    Collagen is commonly used as a tissue-engineering scaffold, yet its in vivo applications are limited by a deficiency in mechanical strength. The purpose of this work was to explore the utilization of a unique enzymatic crosslinking procedure aimed at improving the mechanical properties of collagen-based scaffold materials. Type I bovine collagen gel was crosslinked by transglutaminase, which selectively mediates the chemical reaction between glutamine and lysine residues on adjacent protein fibers, thus providing covalent amide bonds that serve to reinforce the three-dimensional matrix. The degree of crosslinking was verified by thermal analysis and amine group content. The denaturation temperature of crosslinked collagen reached a maximum of 66 +/- 1 degrees C. The chemical reaction was confirmed to be noncytotoxic with respect to bone marrow stromal cells acquired from New Zealand White rabbits. Tube-shaped cellular constructs fashioned from crosslinked collagen and bone marrow stromal cells were found to have burst pressures significantly higher than their noncrosslinked analogs (71 +/- 4 mmHg vs. 46 +/- 3 mmHg; p collagen gels while remaining benign toward cells. Copyright 2004 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 756-762, 2004

  9. Cardiopulmonary Manifestations of Collagen Vascular Diseases.

    Science.gov (United States)

    Jawad, Hamza; McWilliams, Sebastian R; Bhalla, Sanjeev

    2017-10-09

    The study aimed to illustrate the cardiopulmonary findings of the following collagen vascular diseases on cross-sectional imaging: rheumatoid arthritis, scleroderma (progressive systemic sclerosis), systemic lupus erythematosus, the inflammatory myopathies (polymyositis/dermatomyositis), and Sjögren's syndrome. Although collagen vascular diseases can affect any part of the body, interstitial lung disease and pulmonary hypertension are the two most important cardiopulmonary complications and are responsible for the majority of morbidity and mortality in this patient population. Interstitial pneumonia with autoimmune features (IPAF) is a newly described entity that encompasses interstitial lung disease in patients with clinical, serologic, or morphologic features suggestive of but not diagnostic of collagen vascular disease; these patients are thought to have better outcomes than idiopathic interstitial pneumonias. Interstitial lung disease and pulmonary hypertension determine the prognosis in collagen vascular disease patients. IPAF is a new term to label patients with possible collagen vascular disease-related interstitial lung disease. Collagen vascular disease patients are at increased risk for various malignancies.

  10. Inhibition of collagen synthesis by select calcium and sodium channel blockers can be mitigated by ascorbic acid and ascorbyl palmitate.

    Science.gov (United States)

    Ivanov, Vadim; Ivanova, Svetlana; Kalinovsky, Tatiana; Niedzwiecki, Aleksandra; Rath, Matthias

    2016-01-01

    Calcium, sodium and potassium channel blockers are widely prescribed medications for a variety of health problems, most frequently for cardiac arrhythmias, hypertension, angina pectoris and other disorders. However, chronic application of channel blockers is associated with numerous side effects, including worsening cardiac pathology. For example, nifedipine, a calcium-channel blocker was found to be associated with increased mortality and increased risk for myocardial infarction. In addition to the side effects mentioned above by different channel blockers, these drugs can cause arterial wall damage, thereby contributing to vascular wall structure destabilization and promoting events facilitating rupture of plaques. Collagen synthesis is regulated by ascorbic acid, which is also essential for its optimum structure as a cofactor in lysine and proline hydroxylation, a precondition for optimum crosslinking of collagen and elastin. Therefore, the main objective in this study was to evaluate effects of various types of channel blockers on intracellular accumulation and cellular functions of ascorbate, specifically in relation to formation and extracellular deposition of major collagen types relevant for vascular function. Effects of select Na- and Ca- channel blockers on collagen synthesis and deposition were evaluated in cultured human dermal fibroblasts and aortic smooth muscle cells by immunoassay. All channel blockers tested demonstrated inhibitory effects on collagen type I deposition to the ECM by fibroblasts, each to a different degree. Ascorbic acid significantly increased collagen I ECM deposition. Nifedipine (50 µM), a representative of channel blockers tested, significantly reduced ascorbic acid and ascorbyl palmitate-dependent ECM deposition of collagen type l and collagen type lV by cultured aortic smooth muscle cells. In addition, nifedipine (50 µM) significantly reduced ascorbate-dependent collagen type l and type lV synthesis by cultured aortic smooth

  11. Low-Level Light Therapy with 410 nm Light Emitting Diode Suppresses Collagen Synthesis in Human Keloid Fibroblasts: An In Vitro Study

    OpenAIRE

    Lee, Hyun Soo; Jung, Soo-Eun; Kim, Sue Kyung; Kim, You-Sun; Sohn, Seonghyang; Kim, You Chan

    2017-01-01

    Background Keloids are characterized by excessive collagen deposition in the dermis, in which transforming growth factor ? (TGF-?)/Smad signaling plays an important role. Low-level light therapy (LLLT) is reported as effective in preventing keloids in clinical reports, recently. To date, studies investigating the effect of LLLT on keloid fibroblasts are extremely rare. Objective We investigated the effect of LLLT with blue (410 nm), red (630 nm), and infrared (830 nm) light on the collagen sy...

  12. Construction of a collagen-based, split-thickness cornea substitute.

    Science.gov (United States)

    Acun, A; Hasirci, V

    2014-01-01

    Tissue-engineered corneas may become a promising alternative to allografts in the treatment of serious cornea defects because of the tunable characteristics of the biomaterials, biomimetic designs, and incorporation of patient's own cells. In this study, collagen foam was coated with a fibrous mat to mimic the stromal layer and the Bowman's layer. The stromal layer substitute was made of N-ethyl-N-(3-dimethyl aminopropyl)carbodiimide/N-hydroxysuccinimide-cross-linked collagen-chondroitin sulfate foam and seeded with primary human corneal keratocytes (HK). Retinal pigment epithelium (RPE) cells served as the epithelial layer after seeding on a dehydrothermally cross-linked collagen type I fibrous mat deposited directly on top of the foams by electrospinning. The physical characterization and the in vitro studies showed that the designed cornea replacement was suitable for cell attachment and growth, and co-culture of the two cell types induced more extracellular matrix (ECM) deposition than the single cell-seeded constructs. The fiber layer was shown to be successful in separating the HK and RPE cells, and still allowed them to maintain cell-cell communication as the increase in ECM deposition and the maintenance of the high transparency (~80%) suggested. This split-thickness corneal substitute was also shown to be readily suturable without any major tears at the end of a short co-culture of 30 days.

  13. Comparison of wavefront aberration changes in the anterior corneal surface after laser-assisted subepithelial keratectomy and laser in situ keratomileusis: preliminary study.

    Science.gov (United States)

    Buzzonetti, Luca; Iarossi, Giancarlo; Valente, Paola; Volpi, Marzia; Petrocelli, Gianni; Scullica, Luigi

    2004-09-01

    To compare changes in anterior corneal wavefront aberrations after myopic laser-assisted subepithelial keratectomy (LASEK) and laser in situ keratomileusis (LASIK). Institute of Ophthalmology, Catholic University, Rome, Italy. This prospective study included 36 eyes of 25 myopic patients: 18 eyes of 12 patients had LASEK and 18 eyes of 13 patients, LASIK. The topography data (CSO EyeMap, version 6.2) were used to calculate corneal aberrations with 3.0 mm and 7.0 mm pupils before and 3 months after surgery. Total corneal aberrations increased similarly after LASEK and LASIK with the 7.0 mm pupil but did not change with the 3.0 mm pupil. Coma-like and spherical-like aberrations changed similarly after both procedures, but spherical-like aberrations increased after LASEK with the 3.0 mm pupil (P.05, independent t test), in individual eyes with an achieved correction less than 7.50 diopters (D), spherical-like aberrations increased more after LASEK than after LASIK. In this preliminary study, myopic LASEK and LASIK changed total and higher-order corneal aberrations. In both procedures, changes in spherical-like aberrations were dependent on the achieved correction. However, in individual eyes, spherical-like aberrations increased more after LASEK than after LASIK for low-moderate achieved correction, suggesting that these procedures may induce the same optical changes in the anterior corneal surface in different ways.

  14. Implant associated soft tissue defects in the anterior maxilla: a randomized control trial comparing subepithelial connective tissue graft and acellular dermal matrix allograft.

    Science.gov (United States)

    Anderson, Lauren E; Inglehart, Marita R; El-Kholy, Karim; Eber, Robert; Wang, Hom-Lay

    2014-08-01

    This randomized controlled clinical pilot trial compared the efficacy of 2 soft tissue grafting methods for correcting esthetic discrepancies associated with definitively restored implant crowns. Thirteen patients presenting with implants displaying recession, thin biotype, concavity defects, or a combination thereof associated with single crowned dental implants randomly received subepithelial connective tissue grafts (SCTG) in the control group (N = 7) or acellular dermal matrix (ADM) allografts in the test group (N = 6), both under coronally positioned flaps. Data regarding soft tissue, hard tissue, esthetics, and quality of life (QoL) parameters were collected over 6 months. Both groups gained tissue thickness (SCTG: 63% and ADM: 105%), reduced concavity measures (SCTG: 82% and ADM: 96%), and improved recessions (SCTG: 40% and ADM: 28%) from baseline to 6 months. Clinicians determined improvement in esthetics for both groups (P = 0.001), unlike patients who did not change their esthetic ratings. No statistical differences were noted for QoL assessment; however, ADM subjects had more eventful wound healing (P = 0.021). Within the limitations of this study, both SCTG and ADM result in increased mucosal thickness, reduction in concavity dimensions, and have a potential for recession reduction on definitively restored dental implants.

  15. Comparative evaluation of Subepithelial Connective Tissue Graft (SCTG and Acellular Dermal Matrix Allograft (ADMA in the treatment of localized gingival recession- A clinical study

    Directory of Open Access Journals (Sweden)

    A B Tarun Kumar

    2009-01-01

    Full Text Available Gingival recession is the one of the commonest clinical features of chronic periodontitis and poses a great esthetic and functional problem to the patient. Several treatment modalities have been described in the dental literature to treat the localized gingival recession. In the present study, the efficacy of subepithelial connective tissue graft (SCTG and the acellular dermal matrix allograft (ADMA was evaluated and compared in the treatment of localized gingival recession. Nine patients with bilateral identical Miller′s class I or II were selected and randomly assigned to treatment with either SCTG or the ADMA. Six months follow-up result showed significant clinical outcome in both the treatment groups in terms of improvement in recession depth, root coverage percentage, probing depth, clinical attachment level and the width of keratinized tissue. However on comparison between the two groups, no significant difference was found in relation to any of the parameters. Hence, it can be concluded that both the techniques (SCTG & ADMA are equally effective in the treatment of localized gingival recession and restoring the esthetic and function.

  16. A 12 Months Clinical and Radiographic Study to Assess the Efficacy of Open Flap Debridement and Subepithelial Connective Tissue Graft in Management of Supracrestal Defects

    Science.gov (United States)

    Chhina, Shivjot

    2015-01-01

    Background: An improvement in clinical parameters along with regeneration is the desired outcome of periodontal therapy. The aim of this study was to analyze and contrast the efficaciousness of combined open flap debridement (OFD) and subepithelial connective tissue graft (SECTG) to OFD in the management of periodontal supracrestal defects. Materials and Methods: Totally, 20 paired sites exhibiting supracrestal defects were subjected to surgical treatment adopting the split mouth design. The defects were divided randomly for treatment with OFD and SECTG (test) or OFD alone (control). The clinical effectiveness of the two arms of treatment was evaluated at 6 months and 12 months post-operatively by assessing clinical and radiographic parameters. The measurements carried out included probing pocket depth (PPD), relative attachment level (RAL), gingival marginal level, radiographic bone level (BL). Results: The mean reduction in PPD at 0-12 months was 3.20 ± 0.82 mm and RAL gain of 3.10 ± 1.51 mm was observed, the OFD and SECTG (test) group; corresponding observations for OFD (control) were 2.10 ± 0.63 mm and 1.90 ± 0.57 mm. However, BL changes did not follow the pattern of clinical improvement on the radiographic assessment of either treatment group. Post-operative evaluation was made. Improvement in different clinical parameters was statistically significant (P < 0.01). Conclusion: Treatment of supracrestal defects with a combination of OFD and SECTG led to significantly better clinical results compared to OFD alone. PMID:26464551

  17. Effect of physical therapy on joint range of motion and muscle collagen deposition in the golden retriever muscular dystrophy (GRMD model Efeito da fisioterapia na amplitude de movimento articular e deposição de colágeno muscular no modelo golden retriever muscular dystrophy (GRMD

    Directory of Open Access Journals (Sweden)

    TP Gaiad

    2009-06-01

    Full Text Available OBJECTIVE: To elucidate the effect of physical therapy on joint range of motion (ROM and muscle fibrosis in GRMD animals. METHODS: This was a nonrandomized blinded study with a control group, with six months of intervention evaluated beforehand and afterwards. Six dystrophic male Golden Retrievers of mean age 10.16±3.46 months and weight 17.75±6.01 kg were divided into a treated group (n=3 and an untreated group. These groups of dogs were named: G1=treated group before treatment; G2=treated group after treatment; G3=untreated group before treatment; and G4=untreated group after treatment. G1 underwent a physical therapy program that consisted of a 300-meter circuit with obstacles. Stifle, tarsal, elbow and carpal ROM were assessed using a goniometer before and after treatment. The area of collagen in the vastus lateralis muscle was measured using histomorphometry. The locations of collagen types I, III and IV were studied using immunohistochemistry. RESULTS: The tarsal ROM values in G2 presented an increasing trend. The area of muscle collagen differed between the groups after treatment and an increasing trend in these values was observed in G4. Collagen types I and III were the ones most frequently observed, forming broad bands in the perimysium of both G2 and G4. Type I collagen was observed in the endomysium more than type III collagen. Type IV collagen was observed only in the basal layer. CONCLUSION: Physical Therapy seemed to improve tarsal ROM in the treated group without increasing muscular fibrosis.OBJETIVO: Elucidar o efeito da fisioterapia na Amplitude de Movimento Articular (ADM e na fibrose muscular em animais GRMD. MÉTODOS: Estudo não randomizado, com grupo controle, cego, seis meses de intervenção, avaliação antes e depois da intervenção. Seis animais da raça Golden Retriever, distróficos, machos, média de idade 10,16±3,46 meses e peso de 17,75±6,01 kg foram separados em grupo tratado (n=3 e não tratado. Esses

  18. Immunohistochemical localisation of amelogenin-like proteins and type I collagen and histochemical demonstration of sulphated glycoconjugates in developing enameloid and enamel matrices of the larval urodele (Triturus pyrrhogaster) teeth.

    Science.gov (United States)

    Kogaya, Y

    1999-10-01

    The presence of collagen in enameloid distinguishes it clearly from true enamel, but little is known about the phylogenetic relationship between these 2 tissues. It has previously been reported that amelogenins are the principal proteins of the enamel matrix, that type I collagen and chondroitin sulphates are the predominant matrices in dentine, and that amphibian and reptilian aprismatic enamels, contain no sulphated glycoconjugates, although certain sulphated substances are secreted into mammalian prismatic enamel during matrix formation. The larval urodele (Triturus pyrrhogaster) teeth are known to be composed of enameloid, dentine, and enamel-like tissue. To characterise the tooth matrices, the localisation of amelogenin-like proteins, type I collagen, and sulphated glycoconjugates was investigated. Chondroitin sulphates and fine fibrils immunoreactive for type I collagen were elaborated as the enameloid matrix inside the dental basement membrane. After the matrix had been deposited in full thickness, coarse collagen fibrils also immunoreactive for type I collagen and chondroitin sulphates were deposited below as the first dentine matrix. Further, enamel-like matrix with no collagen fibrils or sulphated glycoconjugates but strongly immunoreactive for amelogenins was deposited on the dentine. Although no immunolabelling for amelogenins was found over the enameloid matrix, at least at the formation stage, the zone of coarse collagen fibrils of dentine was partially immunoreactive as observed in mammalian mantle dentine. From the ontogeny and matrix constituents of larval urodele teeth, it is suggested that enameloid is originally a dentine-like tissue.

  19. Characterization of collagen gel solutions and collagen matrices for cell culture.

    Science.gov (United States)

    Sheu, M T; Huang, J C; Yeh, G C; Ho, H O

    2001-07-01

    The influence of glutaraldehyde as a crosslinking agent to increase the strength of collagen matrices for cell culture was examined in this study. Collagen solutions of 1% were treated with different concentrations (0-0.2%) of glutaraldehyde for 24 h. The viscoelasticity of the resulting collagen gel solution was measured using dynamic mechanical analysis (DMA), which demonstrated that all collagen gel solutions examined followed the same model pattern. The creep compliance model of Voigt-Kelvin satisfactorily described the change of viscoelasticity expressed by these collagen gel solutions. These crosslinked collagen gel solutions were freeze-dried to form a matrix with a thickness of about 0.2-0.3 mm. The break modulus of these collagen matrices measured by DMA revealed that the higher the degree of crosslinking. the higher the break modulus. The compatibility of fibroblasts isolated from nude mouse skin with these collagen matrices was found to be acceptable at a cell density of 3 x 10(5) cells/cm2 with no contraction, even when using a concentration of glutaraldehyde of up to 0.2%.

  20. 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.

  1. 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

  2. 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

  3. Lysylhydroxylation and non-reducible crosslinking of human supraspinatus tendon collagen: changes with age and in chronic rotator cuff tendinitis.

    Science.gov (United States)

    Bank, R A; TeKoppele, J M; Oostingh, G; Hazleman, B L; Riley, G P

    1999-01-01

    To investigate age related and site specific variations in turnover and chemistry of the collagen network in healthy tendons as well as the role of collagen remodelling in the degeneration of the supraspinatus tendon (ST-D) in rotator cuff tendinitis. Collagen content and the amount of hydroxylysine (Hyl), hydroxy-lysylpyridinoline (HP), lysylpyridinoline (LP), and the degree of non-enzymatic glycation (pentosidine) were investigated in ST-D and in normal human supraspinatus (ST-N) and biceps brachii tendons (BT-N) by high-performance liquid chromatography. In BT-N, tendons that served as control tissue as it shows rarely matrix abnormalities, pentosidine levels rise linearly with age (20-90 years), indicating little tissue remodelling (resulting in an undisturbed accumulation of pentosidine). A similar accumulation was observed in ST-N up to 50 years. At older ages, little pentosidine accumulation was observed and pentosidine levels showed large interindividual variability. This was interpreted as remodelling of collagen in normal ST after age 50 years because of microruptures (thus diluting old collagen with newly synthesised collagen). All degenerate ST samples showed decreased pentosidine levels compared with age matched controls, indicating extensive remodelling in an attempt to repair the tendon defect. Collagen content and the amount of Hyl, HP, and LP of ST-N and BT-N did not change with age. With the exception of collagen content, which did not differ, all parameters were significantly (p collagen content and had higher Hyl, HP, and LP levels than ST-N (p collagen. On the other hand, the clearly different profile of post-translational modifications in ST-D indicates that the newly deposited collagen network in degenerated tendons is qualitatively different. It is concluded that in ST-D the previously functional and carefully constructed matrix is replaced by aberrant collagen. This may result in a mechanically less stable tendon; as the supraspinatus is

  4. Collagen mineralization in human aortic valve stenosis: a field emission scanning electron microscopy and energy dispersive spectroscopy analysis.

    Science.gov (United States)

    Perrotta, Ida; Davoli, Mariano

    2014-08-01

    Abstract Calcific aortic stenosis is a slowly progressive disorder characterized by an important extracellular matrix remodeling with fibrosis and massive deposition of minerals (primarily calcium) in the valve leaflet. The main structural components of human aortic valve are the large, thick collagen bundles that withstand the diastolic loading. Collagen has been studied in a number of reports that aim to clarify the mechanisms underlying the structural deterioration of heart valve substitutes, however to date, little is known regarding the morphological interaction between collagen and mineral crystals in the calcifying tissue of native aortic valve. Here, we have analyzed a total of 12 calcified native aortic valves by using scanning electron microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX) to depict the morphological appearance of mineralized collagen and to determine the location of calcium phosphate minerals in the collagen matrix of the valve cusp. Our results demonstrate that crystals probably nucleate and grow in the interior of the collagen fibers in the absence of surface events.

  5. Relevance of omental pericellular adipose tissue collagen in the pathophysiology of human abdominal obesity and related cardiometabolic risk.

    Science.gov (United States)

    Michaud, A; Tordjman, J; Pelletier, M; Liu, Y; Laforest, S; Noël, S; Le Naour, G; Bouchard, C; Clément, K; Tchernof, A

    2016-12-01

    Adipose tissue fibrosis is a relatively new notion and its relationship with visceral obesity and cardiometabolic alterations remains unclear, particularly in moderate obesity. Our objective was to examine if total and pericellular collagen accumulation are relevant for the pathophysiology of visceral obesity and related cardiometabolic risk. Surgical omental (OM) and subcutaneous (SC) fat samples were obtained in 56 women (age: 47.2±5.8 years; body mass index (BMI): 27.1±4.4 kg/m2). Body composition and fat distribution were measured by dual-energy X-ray absorptiometry and computed tomography, respectively. Total and pericellular collagen were measured using picrosirius red staining. CD68+ cells (total macrophages) and CD163+ cells (M2-macrophages) were identified using immunohistochemistry. We found that only pericellular collagen percentage, especially in OM fat, was associated with higher BMI, body fat mass and adipose tissue areas as well as lower radiologic attenuation of visceral adipose tissue and altered cardiometabolic risk variables. Strong correlations between peri-adipocyte collagen percentage and total or M2-macrophage percentages were observed in both depots. Total collagen percentage in either compartment was not related to adiposity, fat distribution or cardiometabolic risk. As opposed to whole tissue-based assessments of adipose tissue fibrosis, collagen deposition around the adipocyte, especially in the OM fat compartment is related to total and regional adiposity as well as altered cardiometabolic risk profile.

  6. Triple-helical collagen hydrogels via covalent aromatic functionalization with 1,3-Phenylenediacetic acid.

    Science.gov (United States)

    Tronci, Giuseppe; Doyle, Amanda; Russell, Stephen J; Wood, David J

    2013-10-28

    Chemical crosslinking of collagen is a general strategy to reproduce macroscale tissue properties in physiological environment. However, simultaneous control of protein conformation, material properties and biofunctionality is highly challenging with current synthetic strategies. Consequently, the potentially-diverse clinical applications of collagen-based biomaterials cannot be fully realised. In order to establish defined biomacromolecular systems for mineralised tissue applications, type I collagen was functionalised with 1,3-Phenylenediacetic acid (Ph) and investigated at the molecular, macroscopic and functional levels. Preserved triple helix conformation was observed in obtained covalent networks via ATR-FTIR ( A III /A 1450 ~ 1) and WAXS, while network crosslinking degree ( C : 87-99 mol.-%) could be adjusted based on specific reaction conditions. Decreased swelling ratio ( SR : 823-1285 wt.-%) and increased thermo-mechanical ( T d : 80-88 °C; E : 28-35 kPa; σ max : 6-8 kPa; ε b : 53-58 %) properties were observed compared to state-of-the-art carbodiimide (EDC)-crosslinked collagen controls, likely related to the intermolecular covalent incorporation of the aromatic segment. Ph-crosslinked hydrogels displayed nearly intact material integrity and only a slight mass decrease ( M R : 5-11 wt. %) following 1-week incubation in either PBS or simulated body fluid (SBF), in contrast to EDC-crosslinked collagen ( M R : 33-58 wt. %). Furthermore, FTIR, SEM and EDS revealed deposition of a calcium-phosphate phase on SBF-retrieved samples, whereby an increased calcium phosphate ratio ( Ca/P : 0.84-1.41) was observed in hydrogels with higher Ph content. 72-hour material extracts were well tolerated by L929 mouse fibroblasts, whereby cell confluence and metabolic activity (MTS assay) were comparable to those of cells cultured in cell culture medium (positive control). In light of their controlled structure-function properties, these biocompatible collagen hydrogels

  7. Atorvastatin Improves Ventricular Remodeling after Myocardial Infarction by Interfering with Collagen Metabolism.

    Science.gov (United States)

    Reichert, Karla; Pereira do Carmo, Helison Rafael; Galluce Torina, Anali; Diógenes de Carvalho, Daniela; Carvalho Sposito, Andrei; de Souza Vilarinho, Karlos Alexandre; da Mota Silveira-Filho, Lindemberg; Martins de Oliveira, Pedro Paulo; Petrucci, Orlando

    2016-01-01

    Therapeutic strategies that modulate ventricular remodeling can be useful after acute myocardial infarction (MI). In particular, statins may exert effects on molecular pathways involved in collagen metabolism. The aim of this study was to determine whether treatment with atorvastatin for 4 weeks would lead to changes in collagen metabolism and ventricular remodeling in a rat model of MI. Male Wistar rats were used in this study. MI was induced in rats by ligation of the left anterior descending coronary artery (LAD). Animals were randomized into three groups, according to treatment: sham surgery without LAD ligation (sham group, n = 14), LAD ligation followed by 10mg atorvastatin/kg/day for 4 weeks (atorvastatin group, n = 24), or LAD ligation followed by saline solution for 4 weeks (control group, n = 27). After 4 weeks, hemodynamic characteristics were obtained by a pressure-volume catheter. Hearts were removed, and the left ventricles were subjected to histologic analysis of the extents of fibrosis and collagen deposition, as well as the myocyte cross-sectional area. Expression levels of mediators involved in collagen metabolism and inflammation were also assessed. End-diastolic volume, fibrotic content, and myocyte cross-sectional area were significantly reduced in the atorvastatin compared to the control group. Atorvastatin modulated expression levels of proteins related to collagen metabolism, including MMP1, TIMP1, COL I, PCPE, and SPARC, in remote infarct regions. Atorvastatin had anti-inflammatory effects, as indicated by lower expression levels of TLR4, IL-1, and NF-kB p50. Treatment with atorvastatin for 4 weeks was able to attenuate ventricular dysfunction, fibrosis, and left ventricular hypertrophy after MI in rats, perhaps in part through effects on collagen metabolism and inflammation. Atorvastatin may be useful for limiting ventricular remodeling after myocardial ischemic events.

  8. Immunostimulatory effects of collagen from jellyfish in vivo.

    Science.gov (United States)

    Morishige, Hitoshi; Sugahara, Takuya; Nishimoto, Sogo; Muranaka, Ayako; Ohno, Fumi; Shiraishi, Ryusuke; Doi, Mikiharu

    2011-10-01

    We focused on the biological activity of the collagen extracts obtained from the giant edible jellyfish, Nemopilema nomurai. Jellyfish collagen extracts stimulates the production of immunoglobulins (Igs) and cytokines by human hybridoma cells and human peripheral blood lymphocytes. Therefore, we examined the immunoregulatory function of jellyfish collagen extracts in mice. Intake of jellyfish collagen extracts facilitated the Ig production activity of lymphocytes from spleen and Peyer's patch. Furthermore, the levels of Igs in the serum clearly increased after the administration of jellyfish collagen extracts. Intake of bovine collagen from Achilles' tendon also activated lymphocytes activity in mice. The activity of total and antigen-specific Ig production in splenocytes from OVA-challenged mice was also enhanced by collagen intake. However, the total and OVA-specific IgE levels in the serum were not affected by the collagen intake. These results suggested that jellyfish collagen extracts stimulates an immune response in vivo, without inducing allergic complications.

  9. In vitro collagen fibril assembly: thermodynamic studies.

    Science.gov (United States)

    Na, G C; Phillips, L J; Freire, E I

    1989-09-05

    The in vitro fibril assembly of calf skin collagen was examined as a function of ionic strength and temperature. In a 0.03 M NaPi, pH 7.0, buffer, fibril assembly required a minimum critical concentration of collagen. At nearly physiological ionic strengths and temperatures, the critical concentration was less than 1 microgram/mL and required a very sensitive method for measurement. Raising the ionic strength of the buffer resulted first in higher and then lower critical concentrations. Raising the temperature led to lower critical concentrations. A van't Hoff plot of the fibril growth constant calculated from the critical concentration gave positive enthalpy changes and positive heat capacity changes which indicate that the fibril growth is driven by both hydrophobic and ionic inter-collagen interactions. Sedimentation equilibrium studies showed the collagen to be monomeric at subcritical concentrations. Differential scanning microcalorimetric studies showed only one very sharp heat absorption peak for the fibril assembly which coincided with the appearance of solution turbidity. Within experimental error, the enthalpy changes of the fibril assembly measured with the microcalorimeter were of the same magnitude as the van't Hoff enthalpy changes. These results are discussed in light of a cooperative nucleation-growth mechanism of collagen fibril assembly proposed earlier.

  10. Myofibroblasts are responsible for collagen synthesis in the stroma of human hepatocellular carcinoma: an in vivo and in vitro study.

    Science.gov (United States)

    Faouzi, S; Le Bail, B; Neaud, V; Boussarie, L; Saric, J; Bioulac-Sage, P; Balabaud, C; Rosenbaum, J

    1999-02-01

    Marked changes in extracellular matrix occur in the stroma of hepatocellular carcinoma, as compared to normal or cirrhotic liver. The cell types responsible for extracellular matrix synthesis within hepatocellular carcinoma have not been clearly identified. In vivo collagen synthesis was studied by in situ hybridization and immunohistochemistry for types I, IV, V and VI collagen, together with immunolabeling of alpha-smooth muscle actin, a myofibroblast marker, and CD34, an endothelial cell marker. In vitro, extracellular matrix deposition by cultured myofibroblasts was studied by reticulin staining, immunocytochemistry and RNase protection. All collagens studied were expressed in the stroma of the tumor, with a higher level of type VI and IV collagens than of type I and V. The majority of the cells expressing collagen transcripts in human hepatocellular carcinoma stroma were alpha-actin positive and CD 34 negative. In vitro experiments demonstrated that the hepatocellular carcinoma cell lines HepG2, HuH7 and Hep3B markedly increased extracellular matrix deposition by human liver myofibroblasts. This increase was mediated by a soluble mediator present in tumor cell conditioned medium. It was not explained by an increase in mRNA levels of extracellular matrix components, nor by a decrease in the secretion of matrix-degrading proteinases by myofibroblasts. Myofibroblasts are the main source of collagens in the stroma of hepatocellular carcinoma. Our data also indicate that tumoral hepatocytes increase extracellular matrix deposition by cultured myofibroblasts, probably by post-transcriptional mechanisms. The generation of hepatocellular carcinoma stroma by myofibroblasts could thus be under control of tumoral cells.

  11. Insulin Modulates Cytokine Release, Collagen and Mucus Secretion in Lung Remodeling of Allergic Diabetic Mice

    Directory of Open Access Journals (Sweden)

    Sabrina S. Ferreira

    2017-06-01

    Full Text Available IntroductionThe role of insulin in lung remodeling in a model of asthma in healthy and diabetic mice was evaluated.Material and methodsDiabetic male BALB/c mice (alloxan, 50 mg/kg, intravenous and controls were sensitized by subcutaneous (s.c. injection of ovalbumin (OA, 20 µg in aluminum hydroxide (Al(OH3, 2 mg 10 days after the alloxan injection and received the same dose 12 days later. Six days after the last sensitization, animals were nebulized with OA solution for 7 days. The first set of diabetic and control mice received 2 and 1 IU, respectively, of s.c. neutral protamine Hagedorn (NPH insulin and were analyzed 8 h later. The second set of diabetic and control mice received 2 and 1 IU, respectively, of insulin 12 h before the OA challenge and half doses of insulin 2 h before each the seven OA challenges. Twenty-four hours after the last challenge, the following analyses were performed: (a quantification of the cells in the bronchoalveolar lavage fluid (BALF, the white cell count, and blood glucose; (b morphological analysis of lung tissues by hematoxylin and eosin staining; (c quantification of collagen deposition in lung tissues and mucus by morphometric analysis of histological sections stained with Masson’s trichrome and periodic acid-Schiff (PAS, respectively; and (d quantification of the cytokine concentrations (IL-4, IL-5, and IL-13 in the BALF supernatant.ResultsCompared to controls, diabetic mice had significantly reduced inflammatory cells (81% in the BALF, no eosinophils in the BALF and peripheral blood and reduced collagen deposition and mucus in the lungs. BALF concentrations of IL-4 (48% and IL-5 (31% decreased and IL-13 was absent. A single dose of insulin restored peripheral blood eosinophils and BALF mononuclear cells but not BALF eosinophils, collagen deposition, and mucus levels. However, multiple doses of insulin restored both total cells and eosinophils in the BALF and peripheral blood, BALF

  12. Insulin Modulates Cytokine Release, Collagen and Mucus Secretion in Lung Remodeling of Allergic Diabetic Mice.

    Science.gov (United States)

    Ferreira, Sabrina S; Nunes, Fernanda P B; Casagrande, Felipe B; Martins, Joilson O

    2017-01-01

    The role of insulin in lung remodeling in a model of asthma in healthy and diabetic mice was evaluated. Diabetic male BALB/c mice (alloxan, 50 mg/kg, intravenous) and controls were sensitized by subcutaneous (s.c.) injection of ovalbumin (OA, 20 µg) in aluminum hydroxide (Al(OH)3, 2 mg) 10 days after the alloxan injection and received the same dose 12 days later. Six days after the last sensitization, animals were nebulized with OA solution for 7 days. The first set of diabetic and control mice received 2 and 1 IU, respectively, of s.c. neutral protamine Hagedorn (NPH) insulin and were analyzed 8 h later. The second set of diabetic and control mice received 2 and 1 IU, respectively, of insulin 12 h before the OA challenge and half doses of insulin 2 h before each the seven OA challenges. Twenty-four hours after the last challenge, the following analyses were performed: (a) quantification of the cells in the bronchoalveolar lavage fluid (BALF), the white cell count, and blood glucose; (b) morphological analysis of lung tissues by hematoxylin and eosin staining; (c) quantification of collagen deposition in lung tissues and mucus by morphometric analysis of histological sections stained with Masson's trichrome and periodic acid-Schiff (PAS), respectively; and (d) quantification of the cytokine concentrations (IL-4, IL-5, and IL-13) in the BALF supernatant. Compared to controls, diabetic mice had significantly reduced inflammatory cells (81%) in the BALF, no eosinophils in the BALF and peripheral blood and reduced collagen deposition and mucus in the lungs. BALF concentrations of IL-4 (48%) and IL-5 (31%) decreased and IL-13 was absent. A single dose of insulin restored peripheral blood eosinophils and BALF mononuclear cells but not BALF eosinophils, collagen deposition, and mucus levels. However, multiple doses of insulin restored both total cells and eosinophils in the BALF and peripheral blood, BALF cytokines, and collagen deposition and mucus

  13. Raman spectroscopy enables noninvasive biochemical identification of the collagen regeneration in cutaneous wound healing of diabetic mice treated with MSCs.

    Science.gov (United States)

    Yan, Wenxia; Liu, Hanping; Deng, Xiaoyuan; Jin, Ying; Sun, Huimin; Li, Caiyun; Wang, Ning; Chu, Jing

    2017-07-01

    Mesenchymal stem cells (MSCs) had been reported as a novel therapeutic strategy for non-healing diabetic cutaneous wound mainly by promoting the formation of extracellular matrix (ECM) and neovasculature. Collagen regeneration is one of the key processes of ECM remodeling in wound healing. Accordingly, rapid assessment of the collagen content in a noninvasive manner can promptly provide objective evaluation for MSC therapy of cutaneous wound healing and strength evidence to adjust therapeutic regimen. In the present study, noninvasive Raman microspectroscopy was used for tracing the regeneration status of collagen during diabetic wound healing with MSCs. Wound tissues of normal mice, diabetic mice, and MSC-treated diabetic mice were subjected to Masson trichrome staining assay and submitted to spectroscopic analysis by Raman microspectroscopy after wounding 7, 14, and 21 days. Masson trichrome staining demonstrated that there was more collagen deposition in diabetic + MSCs group relative to diabetic group. The relative intensity of Raman collagen peak positions at 937, 1004, 1321, 1452, and 1662 cm-1 increased in MSC-treated diabetic group compared to diabetic group, although normal mice group had the highest relative intensity of collagen peak bands. Correlation analysis suggested that the spectral bands had a high positive correlation with the collagen intensity detected by Masson trichrome staining in wound tissues of three groups. Our results demonstrate that Raman microspectroscopy has potential application in rapidly and quantitatively assessing diabetic wound healing with MSCs by monitoring collagen variation, which may provide a novel method for the study of skin regeneration.

  14. Collagenous hydrolysates from untraditional sources of proteins.

    Science.gov (United States)

    Langmaier, F; Mladek, M; Kolomaznik, K; Sukop, S

    2001-08-01

    Sufficiently pure collagenous hydrolysates, suitable for application in skin and hair care cosmetics, have been prepared through biotechnological methods with the use of commercially available enzymatic preparations from short cattle tendons (musculus extensor communis, musculus flexor digitorum, musculus flexor digitorum profundis). These hydrolysates contain neither lipoid nor aminosaccharide components, content of primary amino groups reaches around 1.1 mmol g(-1) and the average molecular weight of the resulting collagenous hydrolysates does not exceed 2000 g mol(-1) (2.0 kDa). Short cattle tendons represent a relatively pure and easily available source of collagens and are, despite their generally known low nutritional value, used only as a feeding mixture component.

  15. Effect of collagen crosslinking on collagen-water interactions (a DSC investigation).

    Science.gov (United States)

    Kopp, J; Bonnet, M; Renou, J P

    1989-01-01

    The effect of collagen cross-linking state on the collagen-water interaction was studied, using Differential Scanning Calorimetry (DSC) which allows the determination of unfreezable water, the variation of enthalpy (delta H) and temperatures of denaturation of collagen to gelatin transition. DSC was performed on intramuscular connective tissue purified with trypsin (control C), depolymerized with penicillamin (P), and reduced with borohydride (B); samples were adjusted with different water contents. For the three tissues, unfreezable water (Wu) and denaturation enthalpy change (delta H) increased with increasing moisture level (Wt); whereas, maximum denaturation temperature (phi M) decreased. The ability of this calorimetric method of investigation to characterize the collagen crosslink state is discussed: maximum limit values of delta H and of Wu decreased significantly with increasing collagen cross-linking degree. Minimum Wt necessary to reach the maximum delta H decreased with crosslinking degree. Likewise significantly different limit values of unfreezable water Wu were reached for smaller Wt the greater the crosslinking of collagen. These results show that the less connective tissues were cross-linked, the more they could bind water. They also demonstrated that the water of collagen hydration can be classified into four states, whose limits vary according to the degree of crosslinking.

  16. Distinct Characteristics of Mandibular Bone Collagen Relative to Long Bone Collagen: Relevance to Clinical Dentistry

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    Takashi Matsuura

    2014-01-01

    Full Text Available Bone undergoes constant remodeling throughout life. The cellular and biochemical mechanisms of bone remodeling vary in a region-specific manner. There are a number of notable differences between the mandible and long bones, including developmental origin, osteogenic potential of mesenchymal stem cells, and the rate of bone turnover. Collagen, the most abundant matrix protein in bone, is responsible for determining the relative strength of particular bones. Posttranslational modifications of collagen, such as intermolecular crosslinking and lysine hydroxylation, are the most essential determinants of bone strength, although the amount of collagen is also important. In comparison to long bones, the mandible has greater collagen content, a lower amount of mature crosslinks, and a lower extent of lysine hydroxylation. The great abundance of immature crosslinks in mandibular collagen suggests that there is a lower rate of cross-link maturation. This means that mandibular collagen is relatively immature and thus more readily undergoes degradation and turnover. The greater rate of remodeling in mandibular collagen likely renders more flexibility to the bone and leaves it more suited to constant exercise. As reviewed here, it is important in clinical dentistry to understand the distinctive features of the bones of the jaw.

  17. Reprogramming cellular phenotype by soft collagen gels.

    Science.gov (United States)

    Ali, M Yakut; Chuang, Chih-Yuan; Saif, M Taher A

    2014-11-28

    A variety of cell types exhibit phenotype changes in response to the mechanical stiffness of the substrate. Many cells excluding neurons display an increase in the spread area, actin stress fiber formation and larger focal adhesion complexes as substrate stiffness increases in a sparsely populated culture. Cell proliferation is also known to directly correlate with these phenotype changes/changes in substrate stiffness. Augmented spreading and proliferation on stiffer substrates require nuclear transcriptional regulator YAP (Yes associated protein) localization in the cell nucleus and is tightly coupled to larger traction force generation. In this study, we show that different types of fibroblasts can exhibit spread morphology, well defined actin stress fibers, and larger focal adhesions even on very soft collagen gels (modulus in hundreds of Pascals) as if they are on hard glass substrates (modulus in GPa, several orders of magnitude higher). Strikingly, we show, for the first time, that augmented spreading and other hard substrate cytoskeleton architectures on soft collagen gels are not correlated with the cell proliferation pattern and do not require YAP localization in the cell nucleus. Finally, we examine the response of human colon carcinoma (HCT-8) cells on soft collagen gels. Recent studies show that human colon carcinoma (HCT-8) cells form multicellular clusters by 2-3 days when cultured on soft polyacrylamide (PA) gels with a wide range of stiffness (0.5-50 kPa) and coated with an extracellular matrix, ECM (collagen monomer/fibronectin). These clusters show limited spreading/wetting on PA gels, form 3D structures at the edges, and eventually display a remarkable, dissociative metastasis like phenotype (MLP), i.e., epithelial to rounded morphological transition after a week of culture on PA gels only, but not on collagen monomer coated stiff polystyrene/glass where they exhibit enhanced wetting and form confluent monolayers. Here, we show that HCT-8 cell

  18. Tenascin-X, Collagen, Elastin and the Ehlers-Danlos Syndrome

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    Bristow, James; Carey, William; Schalkwijk, Joost

    2005-08-31

    Tenascin-X is an extracellular matrix protein initially identified because of its overlap with the human CYP21B gene. Because studies of gene and protein function of other tenascins had been poorly predictive of essential functions in vivo, we used a genetic approach that critically relied on an understanding of the genomic locus to uncover an association between inactivating tenascin-X mutations and novel recessive and dominant forms of Ehlers-Danlos syndrome. Tenascin-X provides the first example of a gene outside of the fibrillar collagens and their processing enzymes that causes Ehlers-Danlos syndrome. Tenascin-X null mice recapitulate the skin findings of the human disease, confirming a causative role for this gene in Ehlers-Danlos syndrome. Further evaluation of these mice showed that tenascin-X is an important regulator of collagen deposition in vivo, suggesting a novel mechanism of disease in this form of Ehlers-Danlos syndrome. Further studies suggest that tenascin-X may do this through both direct and indirect interactions with the collagen fibril. Recent studies show that TNX effects on matrix extend beyond the collagen to the elastogenic pathway and matrix remodeling enzymes. Tenascin-X serves as a compelling example of how human experiments of nature can guide us to an understanding of genes whose function may not be evident from their sequence or in vitro studies of their encoded proteins.

  19. Mechanical & cell culture properties of elastin-like polypeptide, collagen, bioglass, and carbon nanosphere composites.

    Science.gov (United States)

    Wheeler, Tyler S; Sbravati, Nathanael D; Janorkar, Amol V

    2013-10-01

    Collagen, the most commonly used extra-cellular matrix protein for tissue engineering applications, displays poor mechanical properties. Here, we report on the preparation and characterization of novel multi-component composite systems that incorporate a genetically engineered, biocompatible polymer (elastin-like polypeptide, ELP), biodegradable ceramic (45S5 bioglass), carbon nanosphere chains (CNSC), and minimal amount (~25% w/w) of collagen. We hypothesized that incorporation of bioglass and CNSC would improve mechanical properties of the composites. Our results showed that the tensile strength and elastic modulus nearly doubled after addition of the bioglass and CNSC compared to the control ELP-collagen hydrogels. Further, MC3T3-E1 pre-osteoblasts were cultured within the composite hydrogels and a thorough biochemical and morphological characterization was performed. Live/dead assay confirmed high cell viability (>95%) for all hydrogels by day 21 of culture. Alkaline phosphatase (ALP) activity and osteocalcin (OCN) production assessed the pre-osteoblast differentiation. Normalized ALP activity was highest for the cells cultured within ELP-bioglass-collagen hydrogels, while normalized OCN production was equivalent for all hydrogels. Alizarin red staining confirmed the mineral deposition by the cells within all hydrogels. Thus, the multi-component composite hydrogels displayed improved mechanical and cell culture properties and may be suitable scaffold materials for bone tissue engineering.

  20. Biomineralization of bone: a fresh view of the roles of non-collagenous proteins

    Science.gov (United States)

    Gorski, Jeffrey Paul

    2015-01-01

    The impact of genetics has dramatically affected our understanding of the functions of non-collagenous proteins. Specifically, mutations and knockouts have defined their cellular spectrum of actions. However, the biochemical mechanisms mediated by non-collagenous proteins in biomineralization remain elusive. It is likely that this understanding will require more focused functional testing at the protein, cell, and tissue level. Although initially viewed as rather redundant and static acidic calcium binding proteins, it is now clear that non-collagenous proteins in mineralizing tissues represent diverse entities capable of forming multiple protein-protein nteractions which act in positive and negative ways to regulate the process of bone mineralization. Several new examples from the author’s laboratory are provided which illustrate this theme including an apparent activating effect of hydroxyapatite crystals on metalloproteinases. This review emphasizes the view that secreted non-collagenous proteins in mineralizing bone actively participate in the mineralization process and ultimately control where and how much mineral crystal is deposited, as well as determining the quality and biomechanical properties of the mineralized matrix produced. PMID:21622198

  1. Blocking collagen fibril formation in injured knees reduces flexion contracture in a rabbit model.

    Science.gov (United States)

    Steplewski, Andrzej; Fertala, Jolanta; Beredjiklian, Pedro K; Abboud, Joseph A; Wang, Mark L Y; Namdari, Surena; Barlow, Jonathan; Rivlin, Michael; Arnold, William V; Kostas, James; Hou, Cheryl; Fertala, Andrzej

    2017-05-01

    Post-traumatic joint contracture is a frequent orthopaedic complication that limits the movement of injured joints, thereby severely impairing affected patients. Non-surgical and surgical treatments for joint contracture often fail to improve the range of motion. In this study, we tested a hypothesis that limiting the formation of collagen-rich tissue in the capsules of injured joints would reduce the consequences of the fibrotic response and improve joint mobility. We targeted the formation of collagen fibrils, the main component of fibrotic deposits formed within the tissues of injured joints, by employing a relevant rabbit model to test the utility of a custom-engineered antibody. The antibody was delivered directly to the cavities of injured knees in order to block the formation of collagen fibrils produced in response to injury. In comparison to the non-treated control, mechanical tests of the antibody-treated knees demonstrated a significant reduction of flexion contracture. Detailed microscopic and biochemical studies verified that this reduction resulted from the antibody-mediated blocking of the assembly of collagen fibrils. These findings indicate that extracellular processes associated with excessive formation of fibrotic tissue represent a valid target for limiting post-traumatic joint stiffness. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1038-1046, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  2. Incorporation of chitosan nanospheres into thin mineralized collagen coatings for improving the antibacterial effect.

    Science.gov (United States)

    Kong, Ziqiang; Yu, Mengfei; Cheng, Kui; Weng, Wenjian; Wang, Huiming; Lin, Jun; Du, Piyi; Han, Gaorong

    2013-11-01

    It is desired that the coatings on metallic implants have both excellent biological responses and good loading-release capacities of biological factors or drugs. So far, the challenge still remains, because the morphology and composition of the bioactive coatings are usually not favorable for accommodating drug molecules. In this study, we adopted an approach of incorporating chitosan nanospheres into a thin mineralized collagen coating; this approach is based on the good loading-release behavior of the nanospheres and the good cytocompatibility of the thin coating. The incorporation of chitosan nanospheres into the mineralized collagen coatings was realized by electrolytic co-deposition. The morphologies and microstructures of the resulting coatings were characterized by SEM, and the phase and chemical compositions of the coatings were measured by XRD and FTIR. The loading-release capacity for vancomycin hydrochloride (VH) was determined by ultraviolet spectrophotometry. MTS assay was used to evaluate cytocompatibility, and in vitro bacterial adhesion was tested for assessing the antibacterial effects of the VH-loaded coatings. The chitosan nanospheres adhered tightly to collagen fibrils. The incorporated coatings facilitated the sustained release of VH, and had a clear antibacterial effect. The incorporation of chitosan nanospheres into mineralized collagen coatings demonstrates an effective way to improve the drug loading-release capacity for the thin coatings. This formulation had a highly effective biological response. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Safety and efficacy of endoscopic excavation for gastric subepithelial tumors originating from the muscularis propria layer: results from a large study in China.

    Science.gov (United States)

    Zhang, Yu; Ye, Li-Ping; Zhou, Xian-Bin; Mao, Xin-Li; Zhu, Lin-Hong; He, Bi-Li; Huang, Qin

    2013-09-01

    In this retrospective study, we investigated the safety and efficacy of endoscopic excavation of gastric subepithelial tumors (SETs) originating from the muscularis propria (MP) layer. Between November 2007 and June 2012, 212 patients with gastric SETs originating from the MP layer were treated via endoscopic excavation. The key procedures were: (1) injecting a mixture solution (100 mL saline+2 mL indigo carmine+1 mL epinephrine) into the submucosa around the tumor; (2) making a cross-incision of the mucosa and then excavating the tumor by the technique of endoscopic excavation. After the tumor was completely excavated from the MP layer, it was removed using a snare; (3) closing the artificial ulcer with clips. The mean diameter of the 212 tumors was 16.5 mm. Complete resection by endoscopic excavation was achieved in 204 cases (96.2%). The rate of complete resection was significantly higher for tumors 2 cm (91.9%) (P=0.035). Perforation occurred in 32 cases (15.1%), and massive bleeding occurred in 9 cases (4.2%) during the procedure. The rate of perforation was significantly higher for the fundus and the body than for antrum (21.5%, 11.5%, 0%, respectively; P=0.036), and also differed significantly in relation to histologic diagnosis (23.7% for gastrointestinal stromal tumors vs. 7.8% for leiomyoma; P=0.001). Histologic diagnosis showed that the density of gastrointestinal stromal tumors located in the fundus and the body of the stomach was significantly higher than in the antrum (44.1%, 51.9%, 13.3%, respectively; P=0.036). Endoscopic excavation is a safe and efficient method for resecting small (>3.5 cm) gastric SETs originating from the MP layer.

  4. Comparative clinical evaluation of laterally positioned pedicle graft and subepithelial connective tissue graft in the treatment of Miller's Class I and II gingival recession: A 6 months study.

    Science.gov (United States)

    Dulani, Kirti Satish; Bhavsar, Neeta Vijay; Trivedi, Sakshee Rahul; Trivedi, Rahul Anil

    2015-01-01

    The purpose of the study was to compare clinical outcomes of laterally positioned pedicle graft (LPPG) and subepithelial connective tissue graft (SCTG) for treatment of Miller's Class I and II gingival recession defects, at the end of 6 months. Sixty Miller's Class I or II gingival recession defects (≥3 mm) (n = 30 each) on the labial aspect of anterior teeth were treated by either of the above techniques. Clinical parameters including recession depth (RD), width of keratinized gingiva (WKG), percentage of root coverage (%RC), and complete RC were recorded at baseline and 6 months postoperatively. Data were recorded and statistical analysis was done for both intergroup and intragroup. Paired t-test intragroup and Student's t-test intergroup. In LPPG, RD decreased from 4.9 ± 0.99 mm to 1.1 ± 0.3 mm and WKG increased from 0.7 ± 0.87 to 4.5 ± 0.86 mm at 6 months, while in SCTG, RD decreased from 4.67 ± 1.12 mm to 0.46 ± 0.68 mm and WKG increased from 1.1 ± 0.99 to 5.33 ± 0.72 mm at 6 months postoperatively. The values of the soft tissue coverage remained stable for 6 months. Highly significant and effective soft tissue coverage was obtained by both techniques. LPPG resulted in effective soft tissue coverage for isolated deep narrow defects while SCTG in isolated and multiple, deep narrow and wide defects.

  5. Comparative evaluation of recession coverage with sub-epithelial connective tissue graft using macrosurgical and microsurgical approaches: A randomized split mouth study

    Directory of Open Access Journals (Sweden)

    Uditi Jindal

    2015-01-01

    Full Text Available Aims: The aim was to compare the recession coverage outcomes when done macrosurgically and microsurgically. Background: Increasing interest in esthetics and the related problems such as hypersensitivity and root caries have favored the development of many root coverage procedures. Recession coverage up to a certain extent has solved these problems, but these procedures need good maintenance after the surgery for long-term benefits. With increasing advances in the field of recession coverage, microscope has added another dimension in undertaking the surgical procedure. Materials and Methods: Thirty Miller′s Class I and II recession were treated using the sub-epithelial connective tissue graft from the palate. In 15 sites, the graft was placed at the recipient site with unaided eye (Group A and in other 15 sites the graft was placed using surgical microscope (Group B. Clinical evaluation was done at baseline, 12 weeks and 24 weeks postoperatively using plaque index, gingival index, vertical recession (VR, probing depth, clinical attachment level (CAL, width of attached gingiva, papilla height (PH and width, malalignment index (MI and esthetic appearance. Statistical Analysis Used: Paired and unpaired Student′s t-test along with Wilcoxon Z-test were used to analyze the results and probability of P < 0.05 were accepted to reject the null hypothesis. Pearson correlation was used to correlate two parameters such as VR and CAL and MI and VR. Results: Both the techniques demonstrated predictable mean root coverage (Group A 61.78% and Group B 67.58% at 6 months postsurgery. CAL gain was slightly better in Group B patients when compared to Group A patients. A moderate positive correlation for Group A while a mild correlation in Group B was seen between the MI and VR. Conclusion: The use of the microscope enhances the results, but obtaining an expertise in using needs a lot of practice. The periodontal healing by both techniques should be evaluated

  6. A comparative evaluation of the effectiveness of subpedicle acellular dermal matrix allograft with subepithelial connective tissue graft in the treatment of isolated marginal tissue recession: A clinical study

    Science.gov (United States)

    Shori, Tony; Kolte, Abhay; Kher, Vishal; Dharamthok, Swarup; Shrirao, Tushar

    2013-01-01

    Introduction: The most common problem encountered in our day to day practice is exposed root surface or a tooth getting long. The main indication for root coverage procedures are esthetics and/or cosmetic demands followed by the management of root hypersensitivity, root caries or when it hampers proper plaque removal. Over the years, various techniques have been used to achieve root coverage. Aim and Objectives: The aim of this study was to compare the effectiveness of subpedicle acellular dermal matrix allograft (ADMA) with subepithelial connective tissue graft (SCTG) in the treatment of isolated marginal tissue recession. Materials and Methods: Twenty systemically healthy patients aged between 18 to 50 years (mean age29.7±4.35 years) with a recession defect on the labial and the buccal surfaces of any teeth were selected for the study. Ten patients received the test treatment (ADMA), ten patients received the control treatment (SCTG). Clinical recordings assessed at baseline, three months and six months post surgery, included Plaque index (PI), Papillary bleeding index (PBI), Gingival recession (REC), Probing pocket depth (PPD), Clinical attachment level (CAL) and Width of keratinized gingival (WKG). Results: Test group (ADMA) showed 86.93% mean root coverage while control group (SCTG) showed 84.72% at six months post surgery. Mean increase in the width of keratinized gingiva was significantly greater in the SCTG group (3.3±0.48mm) compared to ADMA group (2.4±0.51mm). Conclusion: Both the treatment produced a significant reduction in gingival recession and probing pocket depth and significant gain in clinical attachment level and width of keratinised gingiva. PMID:23633778

  7. The Use of Platelet-Rich Fibrin Versus Subepithelial Connective Tissue Graft in Treatment of Multiple Gingival Recessions: A Randomized Clinical Trial.

    Science.gov (United States)

    Öncü, Elif

    The objective of this study was to evaluate the clinical effectiveness of platelet-rich fibrin (PRF) membrane used in combination with a modified coronally advanced flap (MCAF) and to compare it with the use of a subepithelial connective tissue graft (SCTG) in combination with a MCAF in treatment of Miller Class I and II bilateral multiple gingival recessions. A total of 20 patients with multiple Miller Class I and II maxillary gingival recession defects participated in this randomized, split-mouth, controlled study. A total of 60 defects received either PRF + MCAF (test group, n = 30) or MCAF with SCTG (control group, n = 30). Gingival recession depth (RD), keratinized tissue width (KTW), probing depth (PD), clinical attachment level (CAL), and gingival thickness (GT) were evaluated at baseline and after 6 months. Patients' discomfort postsurgery was measured by comparing visual analog scale scores. The percentage of root coverage was 84% in the control group and 77.12% in the test group (P = .007). Complete root coverage of the control and test groups was 60% and 50%, respectively (P = .112). KTW and GT increased in both groups from baseline to 6 months (P < .001). At 6 months postoperative, KTW was greater in the control group (P = .024) and GT was higher in the test group (P = .005). Use of a PRF membrane in gingival recession treatment decreased postoperative discomfort compared to SCTG-treated gingival recessions (P < .001). Within the limitations of the present study, it was concluded that localized gingival recessions could be successfully treated with MCAF + PRF as well as MCAF + SCTG. The PRF technique has the bonus advantage of being more comfortable during the postoperative period. The author suggests that the use of PRF is a valid alternative to SCTG for the treatment of localized gingival recessions.

  8. Root coverage using subepithelial connective tissue graft with platelet-rich plasma in the treatment of gingival recession: A clinical study.

    Science.gov (United States)

    Srinivas, B V V; Rupa, N; Halini Kumari, K V; Prasad, S S V; Varalakshmi, U; Sudhakar, K

    2015-08-01

    The presence of gingival recession associated with an insufficient amount of keratinized tissue may indicate gingival augmentation procedure. It is a multifaceted problem for which several treatment options are available. The most predictable technique used for gingival augmentation is the subepithelial connective tissue graft (SCTG). Platelet-rich plasma (PRP) is an enhanced source of growth factors and helps in accelerated periodontal repair and regeneration. The aim of this study was to evaluate the efficacy of SCTG along with PRP in the treatment of Miller's class I and II gingival recessions. Eleven subjects with Miller's class I and II gingival recessions were treated using SCTG with PRP. Clinical variables, including plaque index, gingival index, recession depth (RD), Recession width (RW), width of the keratinized gingiva, probing pocket depth (PD) and clinical attachment level (CAL) were recorded. Patients were recalled at baseline, 3 months, 6 months and 1-year after surgery and clinical recordings were taken. Root coverage percentage (%) was measured at the end of 1-year. The clinical parameters were analyzed during the follow-up period by repeated measures ANOVA test. Twelve months follow-up results showed significant improvements in all the clinical parameters. Reduction of recession resulted in a significant decrease in CAL, PD, RW and RD at the end of 12 months. A statistically significant gain in width of keratinized gingiva and a mean root coverage of 84.72 ± 19.10 was obtained at the end of 12 months. From the results of this study, it may be concluded that SCTG with PRP is an effective and predictable method to treat miller's class I and II gingival recession.

  9. Comparative evaluation of recession coverage with sub-epithelial connective tissue graft using macrosurgical and microsurgical approaches: A randomized split mouth study.

    Science.gov (United States)

    Jindal, Uditi; Pandit, Nymphea; Bali, Deepika; Malik, Rajvir; Gugnani, Shalini

    2015-01-01

    The aim was to compare the recession coverage outcomes when done macrosurgically and microsurgically. Increasing interest in esthetics and the related problems such as hypersensitivity and root caries have favored the development of many root coverage procedures. Recession coverage up to a certain extent has solved these problems, but these procedures need good maintenance after the surgery for long-term benefits. With increasing advances in the field of recession coverage, microscope has added another dimension in undertaking the surgical procedure. Thirty Miller's Class I and II recession were treated using the sub-epithelial connective tissue graft from the palate. In 15 sites, the graft was placed at the recipient site with unaided eye (Group A) and in other 15 sites the graft was placed using surgical microscope (Group B). Clinical evaluation was done at baseline, 12 weeks and 24 weeks postoperatively using plaque index, gingival index, vertical recession (VR), probing depth, clinical attachment level (CAL), width of attached gingiva, papilla height (PH) and width, malalignment index (MI) and esthetic appearance. Paired and unpaired Student's t-test along with Wilcoxon Z-test were used to analyze the results and probability of P < 0.05 were accepted to reject the null hypothesis. Pearson correlation was used to correlate two parameters such as VR and CAL and MI and VR. Both the techniques demonstrated predictable mean root coverage (Group A 61.78% and Group B 67.58%) at 6 months postsurgery. CAL gain was slightly better in Group B patients when compared to Group A patients. A moderate positive correlation for Group A while a mild correlation in Group B was seen between the MI and VR. The use of the microscope enhances the results, but obtaining an expertise in using needs a lot of practice. The periodontal healing by both techniques should be evaluated histologically.

  10. Enamel matrix proteins (Emdogain) in combination with coronally advanced flap or subepithelial connective tissue graft in the treatment of shallow gingival recessions.

    Science.gov (United States)

    Berlucchi, Ignazio; Francetti, Luca; Del Fabbro, Massimo; Testori, Tiziano; Weinstein, Roberto L

    2002-12-01

    This article describes two different surgical techniques of root coverage using Emdogain and shows preliminary results on 26 shallow recessions in 14 patients. For the treatment of 13 recessions, Emdogain was used in combination with a coronally advanced flap (CAF+EMD group). In the other 13 recessions, Emdogain and the flap were used in combination with a subepithelial connective tissue graft (CAF+CTG+EMD group). For the CAF+EMD group, the root coverage at 6 months was 93.97%, with an attachment gain of 3.2 mm; for the CAF+CTG+EMD group, the root coverage was 93.59%, with an attachment gain of 3.4 mm (no statistically significant difference between groups). When complete root coverage was not achieved, the residual recession was 1 mm in four cases and 2 mm in one case. Keratinized gingiva was increased for both groups, but more for the CAF+CTG+EMD group (1.38 mm versus 0.69 mm; statistically significant difference). Clinical attachment level decreased significantly in both groups, from 4.46 to 1.23 mm in the CAF+EMD group, and from 4.62 to 1.23 mm in the CAF+CTG+EMD group. Preliminary results show that Emdogain, in combination with CAF or CAF+CTG for the treatment of Miller Class I or II gingival recessions, displays good clinical results, with percentage of root coverage comparable or superior to other techniques. Further experimental studies on the dynamics of wound healing are needed to prove that EMD is really responsible for improving the percentage of regenerated versus repaired tissues with respect to other techniques.

  11. Extract of feverfew inhibits interactions of human platelets with collagen substrates

    Energy Technology Data Exchange (ETDEWEB)

    Loesche, W.M.; Mazurov, A.V.; Heptinstall, S.; Groenewegen, W.A.; Repin, V.S.; Till, U.

    1987-12-01

    The interaction of platelets with surfaces coated with collagens of type III (C III) or IV (C IV) has been studied by measuring the deposition of /sup 51/Cr-labeled platelets and by scanning electron microscopy (SEM). Experiments were performed using platelet-rich plasma (PRP) and suspensions of gel-filtered platelets (GFP). Platelets were deposited on C III mainly as surface-bound aggregates. In contrast they were deposited on C IV mainly as spread forms of individual cells. Formation of aggregates on C III was more extensive for PRP than for GFP; in contrast platelet spreading on C IV was more extensive for GFP than for PRP. The effects of an extract of the plant feverfew on platelet-collagen interactions were determined. Feverfew extract inhibited the deposition of /sup 51/Cr-labeled platelets on both C III and C IV in a dose-dependent way. Similar concentrations of extract were needed to inhibit the formation of surface-bound aggregates and to inhibit platelet spreading in both PRP and GFP.

  12. Membranoproliferative glomerulonephritis with isolated C3 deposits: case report and literature review.

    Science.gov (United States)

    Darouich, Sihem; Goucha, Rym; Jaafoura, Mohamed Habib; Zekri, Semy; Kheder, Adel; Ben Maiz, Hédi

    2011-02-01

    Membranoproliferative glomerulonephritis with isolated C3 deposits (MPGNC3) is an uncommon condition characterized by overt glomerular C3 deposits in the absence of immunoglobulins and intramembranous dense deposits. Here the authors describe the clinical and morphological features of primary MPGNC3 in a 13-year-old boy and critically review the previously published cases. The patient presented with nephrotic syndrome and microscopic hematuria. Blood tests revealed very low circulating C3 levels. The renal biopsy exhibited subendothelial, subepithelial, and mesangial deposits, with C3 but not immunoglobulins seen on immunofluorescence. This case and the review of the literature indicate that the serum complement profile with decreased levels of C3 and normal levels of classical pathway components together with glomerular deposits containing exclusively complement C3 is highly suggestive of alternative pathway activation. The diagnosis of acquired and/or genetic complement abnormalities in some cases supports that complement dysregulation is implicated in the pathogenesis of MPGNC3. Such data show great promise to provide new therapy strategies based on modulation of the complement system activity.

  13. Expression of VEGF and collagen using a latex biomembrane as bladder replacement in rabbits

    Directory of Open Access Journals (Sweden)

    André Luís Alonso Domingos

    2012-08-01

    Full Text Available OBJECTIVE: To investigate the VEGF expression and collagen deposition using a latex biomembrane as bladder replacement in rabbits. MATERIALS AND METHODS: After partial cystectomy, a patch of a non-vulcanized latex biomembrane (2 x 2 cm was sewn to the bladder of rabbits with 5/0 monofilament polydioxanone sulfate sutures in a watertight manner. Groups of 5 animals were killed at 15, 45 and 90 days after surgery and the bladder was removed. Sections of 5µm were cut and stained with picrosirius-red in order to estimate the amount of extracellular matrix in the graft. To confirm the presence of VEGF in tissues, protein expression was determined by immunohistochemistry. RESULTS: No death, urinary leakage or graft extrusion occurred in any group. All bladders showed a spherical shape. A progressive reduction in the amount of collagen occurred in the graft area and was negatively and linearly correlated with time (p < 0.001. VEGF expression was higher in grafted areas when compared to controls at 15 and 45 days after surgery and decreased with time (p < 0.001. CONCLUSION: The latex biomembrane as a matrix for partial bladder replacement in rabbits promotes temporary collagen deposition and stimulates the angiogenic process.

  14. Crosslinked collagen/chitosan matrix for artificial livers

    NARCIS (Netherlands)

    Wang, X.H.; Li, D.P.; Wang, W.J.; Feng, Q.L.; Cui, F.Z.; Xu, Y.X.; Song, X.H.; van der Werf, Mark

    2003-01-01

    Matrices composed of collagen and chitosan may create an appropriate environment for the regeneration of livers. In this study, we have prepared, characterized and evaluated a new collagen/chitosan matrix (CCM). The CCM was made by using crosslinking agent

  15. Changes in scleral collagen organization in murine chronic experimental glaucoma.

    Science.gov (United States)

    Pijanka, Jacek K; Kimball, Elizabeth C; Pease, Mary E; Abass, Ahmed; Sorensen, Thomas; Nguyen, Thao D; Quigley, Harry A; Boote, Craig

    2014-09-16

    The organization of scleral collagen helps to determine the eye's biomechanical response to intraocular pressure (IOP), and may therefore be important in glaucoma. This study provides a quantitative assessment of changes in scleral collagen fibril organization in bead-induced murine experimental glaucoma. Wide-angle X-ray scattering was used to study the effect of bead-induced glaucoma on posterior scleral collagen organization in one eye of 12 CD1 mice, with untreated fellow eyes serving as controls. Three collagen parameters were measured: the local preferred fibril directions, the degree of collagen anisotropy, and the total fibrillar collagen content. The mouse sclera featured a largely circumferential orientation of fibrillar collagen with respect to the optic nerve head canal. Localized alteration to fibril orientations was evident in the inferior peripapillary sclera of bead-treated eyes. Collagen anisotropy was significantly (Pglaucoma in mice, and potentially in human glaucoma. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  16. Mechanical qualification of collagen membranes used in dentistry

    OpenAIRE

    Emanuela Ortolani; Fabrizio Quadrini; Denise Bellisario; Loredana Santo; Antonella Polimeni; Anna Santarsiero

    2015-01-01

    AIM. The aim of this work is the qualification of commercially available collagen membranes in a comparative manner. The natural origin of collagen makes standardization difficult. Nevertheless, through dimensional and mechanical measures it is possible to mechanically qualify collagen membranes, and compare them. METHODS. Three commercially available collagen membranes used in Guided Bone Regeneration (GBR) and in Guided Tissue Regeneration (GTR) techniques, namely Bio-Gide, Collprotect and ...

  17. Imaging Cells in Three-Dimensional Collagen Matrix

    OpenAIRE

    Artym, Vira V.; Matsumoto, Kazue

    2010-01-01

    The use of in vitro three-dimensional (3D) collagen matrices to mimic an in vivo cellular environment has become increasingly popular and is broadening our understanding of cellular processes and cell - ECM interactions. To study cells in in vitro 3D collagen matrices, both cellular proteins and the collagen matrix must be visualized. In this unit, the authors describe the protocol and provide troubleshooting for immuno-labeling of cells in 3D collagen gels to localize and visualize cellular ...

  18. Cytological diagnosis of collagenous spherulosis of breast

    Directory of Open Access Journals (Sweden)

    Uday A Gokhale

    2014-01-01

    Full Text Available Collagenous spherulosis is a rare entity usually seen in association with benign breast lesions. It is often picked up incidentally with a reported incidence of about 0.2% in cytological material. There are very few reports describing cytomorphological features of collagenous spherulosis. To the best of our knowledge this is the only case reported from the middle-east region. The presence of hyaline spherules surrounded by a single layer of benign myoepithelial cells is the hallmark of collagenous spherulosis on FNA. However, due to close cytological resemblance, it can be misdiagnosed as adenoid cystic carcinoma of the breast. A 40-year-old woman presented with a history of a painless lump in the infraareolar region of left breast for a year. Fine needle aspiration was performed. The smears showed scanty cellularity comprising of cohesive clusters and a few branching fragments of benign ductal epithelial cells closely intermingled with many spherical, acellular homogenous hyaline globules. Few bare bipolar nuclei were noted in the background. A diagnosis of collagenous spherulosis associated with benign proliferative breast disease was made. Cytopathologists need to be aware of this entity in order to differentiate it from adenoid cystic carcinoma of the breast which requires radical treatment.

  19. Glycine functionalized alumina nanoparticles stabilize collagen in ...

    Indian Academy of Sciences (India)

    Al2O3) was then dried under vac- uum for overnight. The products were stored in clean vial and characterized. 2.3 Interaction of Gly@Al2O3 with collagen. In a typical procedure, 10 mg (10 wt%) of Gly@Al2O3 nanoparticles were sonicated in 5 ...

  20. Collagen contribution to meat toughness: Theoretical aspects.

    Science.gov (United States)

    Lepetit, Jacques

    2008-12-01

    One of the major changes in connective tissues during heating is the transformation of the quasi-crystalline structure of collagen into a random-like structure. This molecular change induces a shortening of these tissues and gives them a rubber-like behaviour. In this state, their mechanical properties are dependent on the total number of cross-linked chains present per volume, which can be estimated from the number and the functionality of each cross-link present in the sample. The number of cross-linked chains per volume of meat explains a large amount of the tenderness variation, produced by muscle type, animal age, type, and sex in different species. During heating collagen fibres and fibrils shortening produces a pressure which is also dependent on the total amount of cross-linked chains present per volume, but also on the morphology of endomysial and perimysial envelopes. In meat, during heating, collagen fibres and fibrils thermal shortening is restricted by muscle fibres and muscle fibre bundles. This restriction, which depends on several muscle fibre characteristics, has a strong effect on the final elastic modulus of connective tissues, by changing the respective amount of crystalline and rubber-like fractions in collagen fibres and fibrils after heating. The implications of this phenomenon in tenderness variations are discussed.

  1. Collagen fibril diameter and leather strength.

    Science.gov (United States)

    Wells, Hannah C; Edmonds, Richard L; Kirby, Nigel; Hawley, Adrian; Mudie, Stephen T; Haverkamp, Richard G

    2013-11-27

    The main structural component of leather and skin is type I collagen in the form of strong fibrils. Strength is an important property of leather, and the way in which collagen contributes to the strength is not fully understood. Synchrotron-based small angle X-ray scattering (SAXS) is used to measure the collagen fibril diameter of leather from a range of animals, including sheep and cattle, that had a range of tear strengths. SAXS data were fit to a cylinder model. The collagen fibril diameter and tear strength were found to be correlated in bovine leather (r(2) = 0.59; P = 0.009), with stronger leather having thicker fibrils. There was no correlation between orientation index, i.e., fibril alignment, and fibril diameter for this data set. Ovine leather showed no correlation between tear strength and fibril diameter, nor was there a correlation across a selection of other animal leathers. The findings presented here suggest that there may be a different structural motif in skin compared with tendon, particularly ovine skin or leather, in which the diameter of the individual fibrils contributes less to strength than fibril alignment does.

  2. Reduced collagen accumulation after major surgery

    DEFF Research Database (Denmark)

    Jorgensen, L N; Kallehave, F; Karlsmark, T

    1996-01-01

    .01)). This decline was significantly higher in the six patients who had a postoperative infection (median 3.02 (range -0.06 to 6.14) versus 0.36 (range -1.56 to 12.60) micrograms/cm, P = 0.02). This study shows that major surgery is associated with impairment of subcutaneous collagen accumulation in a test wound...

  3. Controlled self assembly of collagen nanoparticle

    Science.gov (United States)

    Papi, Massimiliano; Palmieri, Valentina; Maulucci, Giuseppe; Arcovito, Giuseppe; Greco, Emanuela; Quintiliani, Gianluca; Fraziano, Maurizio; De Spirito, Marco

    2011-11-01

    In recent years carrier-mediated drug delivery has emerged as a powerful methodology for the treatment of various pathologies. The therapeutic index of traditional and novel drugs is enhanced via the increase of specificity due to targeting of drugs to a particular tissue, cell or intracellular compartment, the control over release kinetics, the protection of the active agent, or a combination of the above. Collagen is an important biomaterial in medical applications and ideal as protein-based drug delivery platform due to its special characteristics, such as biocompatibility, low toxicity, biodegradability, and weak antigenicity. While some many attempts have been made, further work is needed to produce fully biocompatible collagen hydrogels of desired size and able to release drugs on a specific target. In this article we propose a novel method to obtain spherical particles made of polymerized collagen surrounded by DMPC liposomes. The liposomes allow to control both the particles dimension and the gelling environment during the collagen polymerization. Furthermore, an optical based method to visualize and quantify each step of the proposed protocol is detailed and discussed.

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

    Indian Academy of Sciences (India)

    Evaluation of biodegradation and biocompatibility of collagen/chitosan/alkaline phosphatase biopolymeric membranes. E BERTEANU1, D IONITA2,∗, M SIMOIU3, M PARASCHIV1, R TATIA1, A APATEAN1,. M SIDOROFF1 and L TCACENCO1. 1National Institute of Research and Development for Biological Sciences, ...

  5. Biological Safety of Fish (Tilapia Collagen

    Directory of Open Access Journals (Sweden)

    Kohei Yamamoto

    2014-01-01

    Full Text Available Marine collagen derived from fish scales, skin, and bone has been widely investigated for application as a scaffold and carrier due to its bioactive properties, including excellent biocompatibility, low antigenicity, and high biodegradability and cell growth potential. Fish type I collagen is an effective material as a biodegradable scaffold or spacer replicating the natural extracellular matrix, which serves to spatially organize cells, providing them with environmental signals and directing site-specific cellular regulation. This study was conducted to confirm the safety of fish (tilapia atelocollagen for use in clinical application. We performed in vitro and in vivo biological studies of medical materials to investigate the safety of fish collagen. The extract of fish collagen gel was examined to clarify its sterility. All present sterility tests concerning bacteria and viruses (including endotoxin yielded negative results, and all evaluations of cell toxicity, sensitization, chromosomal aberrations, intracutaneous reactions, acute systemic toxicity, pyrogenic reactions, and hemolysis were negative according to the criteria of the ISO and the http://dx.doi.org/10.13039/501100003478 Ministry of Health, Labour and Welfare. The present study demonstrated that atelocollagen prepared from tilapia is a promising biomaterial for use as a scaffold in regenerative medicine.

  6. Biological safety of fish (tilapia) collagen.

    Science.gov (United States)

    Yamamoto, Kohei; Igawa, Kazunari; Sugimoto, Kouji; Yoshizawa, Yuu; Yanagiguchi, Kajiro; Ikeda, Takeshi; Yamada, Shizuka; Hayashi, Yoshihiko

    2014-01-01

    Marine collagen derived from fish scales, skin, and bone has been widely investigated for application as a scaffold and carrier due to its bioactive properties, including excellent biocompatibility, low antigenicity, and high biodegradability and cell growth potential. Fish type I collagen is an effective material as a biodegradable scaffold or spacer replicating the natural extracellular matrix, which serves to spatially organize cells, providing them with environmental signals and directing site-specific cellular regulation. This study was conducted to confirm the safety of fish (tilapia) atelocollagen for use in clinical application. We performed in vitro and in vivo biological studies of medical materials to investigate the safety of fish collagen. The extract of fish collagen gel was examined to clarify its sterility. All present sterility tests concerning bacteria and viruses (including endotoxin) yielded negative results, and all evaluations of cell toxicity, sensitization, chromosomal aberrations, intracutaneous reactions, acute systemic toxicity, pyrogenic reactions, and hemolysis were negative according to the criteria of the ISO and the Ministry of Health, Labour and Welfare of Japan. The present study demonstrated that atelocollagen prepared from tilapia is a promising biomaterial for use as a scaffold in regenerative medicine.

  7. Corneal collagen crosslinking for keratoconus. A review

    Directory of Open Access Journals (Sweden)

    M. M. Bikbov

    2014-01-01

    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

  8. 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

  9. Collagen Type III Degradation Is Associated with Deterioration of Kidney Function in Patients with Type 2 Diabetes with Microalbuminuria

    DEFF Research Database (Denmark)

    Genovese, Federica; Hansen, Tine Wilum; Guldager, Daniel Kring Rasmussen

    Background In diabetes one of the main features of the progression to diabetic kidney disease is a pathological deposition of extracellular matrix components triggering renal fibrosis. The main structural component of the fibrotic core is collagen. One of the most prominent collagens is collagen...... (C3M) was associated with deterioration of kidney function in a well-characterised type 2 diabetic population with microalbuminuria and without symptoms of coronary artery disease. Methods The cohort included 200 participants, followed for 6.1 years. We measured C3M levels in serum (S-C3M) and urine...... factors (sex, age, systolic blood pressure, LDL-cholesterol, smoking, HbA1c, creatinine and urinary albumin excretion rate). To assess whether S-C3M or U-C3M improved risk prediction beyond traditional risk factors we calculated the relative integrated discrimination improvement (rIDI). Results The hazard...

  10. Extracellular Protease Inhibition Alters the Phenotype of Chondrogenically Differentiating Human Mesenchymal Stem Cells (MSCs) in 3D Collagen Microspheres

    Science.gov (United States)

    Han, Sejin; Li, Yuk Yin; Chan, Barbara Pui

    2016-01-01

    Matrix remodeling of cells is highly regulated by proteases and their inhibitors. Nevertheless, how would the chondrogenesis of mesenchymal stem cells (MSCs) be affected, when the balance of the matrix remodeling is disturbed by inhibiting matrix proteases, is incompletely known. Using a previously developed collagen microencapsulation platform, we investigated whether exposing chondrogenically differentiating MSCs to intracellular and extracellular protease inhibitors will affect the extracellular matrix remodeling and hence the outcomes of chondrogenesis. Results showed that inhibition of matrix proteases particularly the extracellular ones favors the phenotype of fibrocartilage rather than hyaline cartilage in chondrogenically differentiating hMSCs by upregulating type I collagen protein deposition and type II collagen gene expression without significantly altering the hypertrophic markers at gene level. This study suggests the potential of manipulating extracellular proteases to alter the outcomes of hMSC chondrogenesis, contributing to future development of differentiation protocols for fibrocartilage tissues for intervertebral disc and meniscus tissue engineering. PMID:26760956

  11. Dynamic viscoelastic properties of collagen gels in the presence and absence of collagen fibrils

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Hideki; Shimizu, Kousuke; Hara, Masayuki, E-mail: hara@b.s.osakafu-u.ac.jp

    2012-10-01

    We measured the dynamic viscoelasticities of collagen gels prepared and modified by four different methods: i) collagen gels cross-linked by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) after their preparation, ii) collagen gels cross-linked simultaneously with their preparation, iii) collagen gels irradiated with gamma rays after their preparation, and iv) collagen gels directly formed from an acidic collagen solution by gamma-cross-linking. Dynamic viscoelasticities of all samples were measured using a rheometer before and after heating for 30 min at 80 Degree-Sign C. The collagen gels sequentially cross-linked by 125 mM EDC after preparation and then heated exhibited mechanically strong properties (storage modulus G Prime , 7010 Pa; loss modulus G Double-Prime , 288 Pa; Young's modulus E, 0.012 in the rapidly-increasing phase and 0.095 in the moderately-increasing phase; tensile strain, 5.29; tensile stress {sigma}, 0.053). We generally conclude that the G Prime value decreases when gels without fibrils are heated. On the other hand, well cross-linked collagen gels with thick fibrils, such as gels sequentially cross-linked with 125 mM EDC after preparation or gamma-cross-linked conventional gels irradiated at 40 kGy, exhibit a distinct increase in G Prime value after heating. Those gels also have thick, twisted, or fused fibrils of collagen. Highlights: Black-Right-Pointing-Pointer Dynamic viscoelasticities of collagen gels prepared and modified by various methods. Black-Right-Pointing-Pointer Chemical cross-linking with EDC and gamma-cross-linking were used. Black-Right-Pointing-Pointer Dynamic viscoelasticities of those samples were measured before and after the heating. Black-Right-Pointing-Pointer The gels sequentially cross-linked with 125 mM EDC exhibit a distinct increase in G' value after heating. Black-Right-Pointing-Pointer Those gels also have thick, twisted, or fused fibrils of collagen.

  12. The decorin sequence SYIRIADTNIT binds collagen type I

    DEFF Research Database (Denmark)

    Kalamajski, Sebastian; Aspberg, Anders; Oldberg, Ake

    2007-01-01

    -directed mutagenesis of this 54-residue-long collagen-binding sequence identifies Arg-207 and Asp-210 in leucine-rich repeat 6 as crucial for the binding to collagen. The synthetic peptide SYIRIADTNIT, which includes Arg-207 and Asp-210, inhibits the binding of full-length recombinant decorin to collagen in vitro...

  13. Collagen derived serum markers in carcinoma of the prostate

    DEFF Research Database (Denmark)

    Rudnicki, M; Jensen, L T; Iversen, P

    1995-01-01

    Three new collagen markers deriving from the collagenous matrix, e.g. carboxyterminal propeptide of type I procollagen (PICP), carboxy-terminal pyridinoline cross-linked telopeptide of type I collagen (ICTP), and aminoterminal propeptide of type III procollagen (PIIINP) were used for the diagnose...

  14. Comparison of the properties of collagen extracted from dried ...

    African Journals Online (AJOL)

    The properties of these proteins have been studied and a comparison made of the protein patterns of collagen extracted from marine organisms with those from other organisms, to determine which collagen subtypes are present, and in what proportions. Pepsin-soluble collagen (PSC) from dried jellyfish and dried squid ...

  15. Directed 2-dimensional organisation of collagen: Role of cross ...

    Indian Academy of Sciences (India)

    Administrator

    –20°C by acetic acid extraction and salting-out with. NaCl. 13. The purity of the collagen preparation was confirmed by sodium dodecyl sulfate–poly- acrylamide gel electrophoresis; the bands appearing in the gel corresponded only to type 1 collagen. The collagen concentration in the solutions was deter- mined from the ...

  16. Collagen based Biomaterials from CLRI: An Inspiration from the ...

    Indian Academy of Sciences (India)

    Treatment Modality · Slide 41 · Collagen: Benefits in wound Healing · Chitosan Cross-linked Reconstituted Amniotic Collagen Membrane – An Excellent Cell Substratum · Slide 44 · Some products from CLRI under clinical use and evaluation · Applying Knowledge on Collagen of CLRI: In Human Health Care · Slide 47.

  17. Spontaneous Gastric Perforation in a Case of Collagenous Gastritis.

    Science.gov (United States)

    Appelman, Marly H; de Meij, Tim G J; Neefjes-Borst, E Andra; Kneepkens, C M F

    2016-01-01

    Collagenous gastritis is an extremely rare disease, both in children and adults. Symptoms vary depending on the extent of collagenous changes in the bowel. In most of the children, iron deficiency anemia and abdominal pain are the presenting symptoms. We present a 15-year-old boy with acute abdomen due to gastric perforation the cause of which was collagenous gastritis.

  18. Dense fibrillar collagen is a master activator of invadopodia

    OpenAIRE

    Artym, Vira V.

    2015-01-01

    Tumor stroma is characterized by abnormal accumulation of dense fibrillar collagen, which promotes tumor progression and metastasis. However, the effect of desmoplastic collagen on cells has been unclear. Our recent findings demonstrate that dense fibrillar collagen activates a novel phosphosignaling mechanism for robust induction of invadopodia in tumor cells and normal fibroblasts.

  19. Dense fibrillar collagen is a master activator of invadopodia.

    Science.gov (United States)

    Artym, Vira V

    2016-05-01

    Tumor stroma is characterized by abnormal accumulation of dense fibrillar collagen, which promotes tumor progression and metastasis. However, the effect of desmoplastic collagen on cells has been unclear. Our recent findings demonstrate that dense fibrillar collagen activates a novel phosphosignaling mechanism for robust induction of invadopodia in tumor cells and normal fibroblasts.

  20. Collagens and collagen-related matrix components in the human and mouse eye.

    Science.gov (United States)

    Ihanamäki, Tapio; Pelliniemi, Lauri J; Vuorio, Eero

    2004-07-01

    The three-dimensional structure of the eye plays an important role in providing a correct optical environment for vision. Much of this function is dependent on the unique structural features of ocular connective tissue, especially of the collagen types and their supramolecular structures. For example, the organization of collagen fibrils is largely responsible for transparency and refraction of cornea, lens and vitreous body, and collagens present in the sclera are largely responsible for the structural strength of the eye. Phylogenetically, most of the collagens are highly conserved between different species, which suggests that collagens also share similar functions in mice and men. Despite considerable differences between the mouse and the human eye, particularly in the proportion of the different tissue components, the difficulty of performing systematic histologic and molecular studies on the human eye has made mouse an appealing alternative to studies addressing the role of individual genes and their mutations in ocular diseases. From a genetic standpoint, the mouse has major advantages over other experimental animals as its genome is better known than that of other species and it can be manipulated by the modern techniques of genetic engineering. Furthermore, it is easy, quick and relatively cheap to produce large quantities of mice for systematic studies. Thus, transgenic techniques have made it possible to study consequences of specific mutations in genes coding for structural components of ocular connective tissues in mice. As these changes in mice have been shown to resemble those in human diseases, mouse models are likely to provide efficient tools for pathogenetic studies on human disorders affecting the extracellular matrix. This review is aimed to clarify the role of collagenous components in the mouse and human eye with a closer look at the new findings of the collagens in the cartilage and the eye, the so-called "cartilage collagens".

  1. Stabilization of Collagen Fibrils by Gelatin Addition: A Study of Collagen/Gelatin Dense Phases

    OpenAIRE

    Portier, François; Teulon, Claire; Nowacka-Perrin, Agnieszka; Guenneau, Flavien; Schanne-Klein, Marie-Claire; Mosser, Gervaise

    2017-01-01

    International audience; Collagen and its denatured form, gelatin, are biopolymers of fundamental interest in numerous fields ranging from living tissues to biomaterials, food, and cosmetics. This study aims at characterizing mixtures of those biopolymers at high concentrations (up to 100 mg·mL–1) at which collagen has mesogenic properties. We use a structural approach combining polarization-resolved multiphoton microscopy, polarized light microscopy, magnetic resonance imaging, and transmissi...

  2. Diastolic tissue Doppler indexes correlate with the degree of collagen expression and cross-linking in heart failure and normal ejection fraction.

    Science.gov (United States)

    Kasner, Mario; Westermann, Dirk; Lopez, Begoña; Gaub, Regina; Escher, Felicitas; Kühl, Uwe; Schultheiss, Heinz-Peter; Tschöpe, Carsten

    2011-02-22

    We attempted to correlate echocardiographic analysis of diastolic function with changes of myocardial collagen in middle-aged patients with heart failure (HF) despite normal ejection fraction (EF). Increased collagen deposition may contribute to the deterioration of the left ventricular compliance and diastolic dysfunction in HF. We investigated 41 patients (median age 50 years [interquartile range: 41 to 57 years]) with normal EF (median 62% [interquartile range: 56% to 70%]) whose endomyocardial biopsies were taken previously. Assessment of diastolic function was performed by mitral-flow and tissue Doppler measurements. Sirius red and immunohistologic staining was performed to determine collagen volume fraction (CVF) and cross-linking, collagen types I and III expression, and lysyl-oxidase (LOX) expression. Expression of collagen messenger ribonucleic acid was determined by real-time polymerase chain reaction. Twenty-six patients with HFNEF with diastolic dysfunction showed a significant increase in total collagen and collagen I expression compared with that of 15 controls. This was accompanied with enhanced collagen cross-linking and LOX overexpression in HFNEF. Among all flow Doppler, only deceleration time of E was associated with CVF (R = 0.43), whereas tissue Doppler parameters correlated with CVF, collagen I at the protein and mRNA levels (E' [R = -0.58, -0.60, -0.45]; E'/A' [R = -0.32, -0.36, -0.31]), and left ventricular filling index (E/E' [R = 0.72, 0.68, 0.63]), respectively. No correlation with collagen III was found. The degree of collagen cross-linking and LOX expression was related to E' (R = -0.55 and -0.60) and E/E' (R = 0.72 and 0.71), respectively, but not to flow Doppler. Collagen overexpression correlated with reduced exercise capacity. Patients with HFNEF showed increased content of myocardial collagen type I, enhanced collagen cross-linking, and LOX expression, which were associated with impaired diastolic tissue Doppler parameters

  3. Visual Outcomes After SMILE, LASEK, and LASEK Combined With Corneal Collagen Cross-Linking for High Myopic Correction.

    Science.gov (United States)

    Hyun, Sangyoon; Lee, Seongjun; Kim, Jae-Hyung

    2017-04-01

    To compare the visual and refractive outcomes of small-incision lenticule extraction (SMILE), laser-assisted subepithelial keratomileusis (LASEK), and LASEK combined with corneal collagen cross-linking (LASEK-CXL) surgery for high-degree myopia. Medical records of patients with spherical equivalent (SE) greater than -6.00 diopters (D) treated with SMILE, LASEK, and LASEK-CXL were reviewed. Uncorrected distance visual acuity (UCVA), SE, and corneal haze were followed up in the 3 groups for 6 months. The SMILE group included 69 eyes, the LASEK group included 61 eyes, and the LASEK-CXL group included 40 eyes. At 6 months postoperatively, there were no statistically significant differences in UCVA between the SMILE, LASEK, and LASEK-CXL groups (logMAR 0.00 ± 0.00, 0.01 ± 0.08, and 0.01 ± 0.08, respectively, P = 0.69). The averages of the absolute value of SE were 0.34 ± 0.25 D, 0.50 ± 0.36 D, and 0.42 ± 0.34 D in the SMILE, LASEK, and LASEK-CXL groups, respectively (P = 0.04). The percentages of the patients with a postoperative residual refractive error within ±0.50 D were 84% in the SMILE group, 65% in the LASEK group, and 76% in the LASEK-CXL group. The percentages of the patients with greater than 20/25 postoperative UCVA were 100%, 91%, and 95%, respectively. SMILE produced no postoperative corneal haze. However, 18% of patients treated with LASEK and 25% of those treated with LASEK-CXL had corneal haze at 6 months postoperatively. SMILE, LASEK, and LASEK-CXL surgery appear to be safe and effective for high-degree myopic correction. However, the SMILE group had no haze and fewer induction of some higher-order aberrations compared with the LASEK and LASEK-CXL groups.

  4. 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

  5. Separation of Solid Stress From Interstitial Fluid Pressure in Pancreas Cancer Correlates With Collagen Area Fraction.

    Science.gov (United States)

    Nieskoski, Michael D; Marra, Kayla; Gunn, Jason R; Kanick, Stephen C; Doyley, Marvin M; Hasan, Tayyaba; Pereira, Stephen P; Stuart Trembly, B; Pogue, Brian W

    2017-06-01

    Elevated total tissue pressure (TTP) in pancreatic adenocarcinoma is often associated with stress applied by cellular proliferation and hydrated hyaluronic acid osmotic swelling; however, the causal roles of collagen in total tissue pressure have yet to be clearly measured. This study illustrates one direct correlation between total tissue pressure and increased deposition of collagen within the tissue matrix. This observation comes from a new modification to a conventional piezoelectric pressure catheter, used to independently separate and quantify total tissue pressure, solid stress (SS), and interstitial fluid pressure (IFP) within the same tumor location, thereby clarifying the relationship between these parameters. Additionally, total tissue pressure shows a direct correlation with verteporfin uptake, demonstrating the impediment of systemically delivered molecules with increased tissue hypertension.

  6. Childhood epidermolysis bullosa acquisita: Confirmation of diagnosis by skin deficient in Type VII Collagen, enzyme-linked immunosorbent assay, and immunoblotting

    Directory of Open Access Journals (Sweden)

    Nupur Goyal

    2016-01-01

    Full Text Available Epidermolysis bullosa acquisita (EBA is an acquired subepidermal bullous disorder characterized by autoantibodies against Type VII collagen. It usually affects adults; childhood EBA is rare. We describe a 10-year-old girl presenting with recurrent tense blisters predominantly on legs, dorsa of hands and feet accompanied by oral erosions since the age of 5 years. Direct immunofluorescence (IF microscopy showed linear deposition of IgG and C3 along the basement membrane zone (BMZ; indirect IF microscopy on salt-split skin revealed staining of IgG to the dermal side of the split. The patient's serum did not show BMZ staining in recessive dystrophic epidermolysis bullosa skin deficient for Type VII collagen, thus confirming autoantibody reactivity against Type VII collagen. Circulating antibodies against the immunodominant noncollagenous 1 domain of Type VII collagen were detected by ELISA and immunoblotting studies. The patient was treated with oral corticosteroids and dapsone with good improvement.

  7. Childhood Epidermolysis Bullosa Acquisita: Confirmation of Diagnosis by Skin Deficient in Type VII Collagen, Enzyme-linked Immunosorbent Assay, and Immunoblotting.

    Science.gov (United States)

    Goyal, Nupur; Rao, Raghavendra; Balachandran, C; Pai, Sathish; Bhogal, Balbir S; Schmidt, Enno; Zillikens, Detlef

    2016-01-01

    Epidermolysis bullosa acquisita (EBA) is an acquired subepidermal bullous disorder characterized by autoantibodies against Type VII collagen. It usually affects adults; childhood EBA is rare. We describe a 10-year-old girl presenting with recurrent tense blisters predominantly on legs, dorsa of hands and feet accompanied by oral erosions since the age of 5 years. Direct immunofluorescence (IF) microscopy showed linear deposition of IgG and C3 along the basement membrane zone (BMZ); indirect IF microscopy on salt-split skin revealed staining of IgG to the dermal side of the split. The patient's serum did not show BMZ staining in recessive dystrophic epidermolysis bullosa skin deficient for Type VII collagen, thus confirming autoantibody reactivity against Type VII collagen. Circulating antibodies against the immunodominant noncollagenous 1 domain of Type VII collagen were detected by ELISA and immunoblotting studies. The patient was treated with oral corticosteroids and dapsone with good improvement.

  8. Expression of type I and type III collagens in oral submucous fibrosis: An immunohistochemical study

    Directory of Open Access Journals (Sweden)

    Venkatesh V Kamath

    2015-01-01

    Full Text Available Background: Oral submucous fibrosis (OSMF is a potentially malignant collagen - metabolic disorder linked to consumption of betel quid and areca nut. The deposition of collagen and its major subtypes have been the subject of intense scrutiny in the etiopathogenesis of the disorder. Aims and Objectives: The present study was planned to immunohistochemically identify the expression of collagens I and III (COL I and III in different grades of OSF and compare it with normal oral mucosa and scar tissue. Materials and Methods: Archival paraffin sections of 72 cases of various grades of OSMF, ten cases of normal mucosa as controls and four cases of scar tissue were stained with antibodies to COL I and III (BioGenex Laboratories, CA, USA to evaluate the collagen subtypes on paraffin sections. The expression was quantified by image analysis software (Jenoptik Optical System, ProgRes ® Capture Pro, version 2.8.8 and statistically analyzed. Results: COL I and III stained all the tissues ubiquitously. COL I was more in ratio and quantity in all the grades of OSMF, normal mucosa, and scar tissue. The proportion of COL I to COL III seemed to increase with progressive grades of OSF. Interestingly, during the process of fibrosis COL III seems to be deposited earlier and gradually replaced by COL I resulting in a skewed ratio vis a vis normal oral mucosa and scar tissue. Conclusions: COL I expression was found to be proportionate with advancing grades of OSF while COL III expression increased in Grade I but subsequently decreased as severity of OSF increased. The increase in COL I at the expense of COL III showed a similar pattern in the submucosa while in the deeper muscle only Grade III cases reflected the trend. While all cases of OSF revealed excessive expression in comparison with normal oral mucosa, the comparison with scar tissue was variable.

  9. [Effect of procyanidolic oligomers on corneal collagen fibrillogenesis].

    Science.gov (United States)

    Robert, A M; Robert, L; Renard, G

    2005-12-01

    We showed in a previous study that procyanidolic oligomers (PCOs) from grape seeds effectively protect corneal stroma against degradation by bacterial collagenase. Here we report the study of the effect of PCOs on protein and collagen composition of cornea and on the biosynthesis of corneal collagens. Bovine corneas were used in explant cultures. We quantitatively determined total proteins and collagen as well as the incorporation of 3H-proline in separated collagen types. Collagens type I, V, and VI were separated and quantitated. In order to understand some of the results obtained, we studied the interaction of PCO with collagen type I separately. In the absence of PCOs, collagen typing and 3H-proline incorporation yielded the expected results for a normal cornea, with the usual proportion of the three major types of collagens. In presence of PCOs at 1 mg/ml and after 24 h incubation, total proteins and collagens decreased, as did papain-extractable collagens. Proteins in the final residue solubilized in 1 M KOH-80% v/v aqueous ethanol increased. The proportion of the three principal collagens was also modified: type I became preponderant, and the proportions of the two others (type V and VI) decreased. The study of the interaction of collagen type I with PCOs showed that 30% of total PCOs do not interact with collagen, 20% interact reversibly, and 50% of PCOs are strongly and irreversibly fixed. This strongly fixed fraction could not be separated from collagen by either column chromatography or collagenase or KOH in aqueous ethanol. Bovine corneas in explant cultures in presence of PCOs undergo a modification of their protein and collagen content, with a concurrent modification of the proportion of collagens types I, V, and VI. Collagen type I predominates, and the two other types decrease. Study of the collagen type I-PCO interaction showed that roughly 50% of PCOs become irreversibly fixed to collagen, resisting collagenase or other methods of separation. This

  10. Neurotrophin 3 upregulates proliferation and collagen production in human aortic valve interstitial cells: a potential role in aortic valve sclerosis.

    Science.gov (United States)

    Yao, Qingzhou; Song, Rui; Ao, Lihua; Cleveland, Joseph C; Fullerton, David A; Meng, Xianzhong

    2017-06-01

    Calcific aortic valve disease (CAVD) is a leading cardiovascular disorder in the elderly. Diseased aortic valves are characterized by sclerosis (fibrosis) and nodular calcification. Sclerosis, an early pathological change, is caused by aortic valve interstitial cell (AVIC) proliferation and overproduction of extracellular matrix (ECM) proteins. However, the mechanism of aortic valve sclerosis remains unclear. Recently, we observed that diseased human aortic valves overexpress growth factor neurotrophin 3 (NT3). In the present study, we tested the hypothesis that NT3 is a profibrogenic factor to human AVICs. AVICs isolated from normal human aortic valves were cultured in M199 growth medium and treated with recombinant human NT3 (0.10 µg/ml). An exposure to NT3 induced AVIC proliferation, upregulated the production of collagen and matrix metalloproteinase (MMP), and augmented collagen deposition. These changes were abolished by inhibition of the Trk receptors. NT3 induced Akt phosphorylation and increased cyclin D1 protein levels in a Trk receptor-dependent fashion. Inhibition of Akt abrogated the effect of NT3 on cyclin D1 production. Furthermore, inhibition of either Akt or cyclin D1 suppressed NT3-induced cellular proliferation and MMP-9 and collagen production, as well as collagen deposition. Thus, NT3 upregulates cellular proliferation, ECM protein production, and collagen deposition in human AVICs. It exerts these effects through the Trk-Akt-cyclin D1 cascade. NT3 is a profibrogenic mediator in human aortic valve, and overproduction of NT3 by aortic valve tissue may contribute to the mechanism of valvular sclerosis. Copyright © 2017 the American Physiological Society.

  11. The insoluble TGFBIp fraction of the cornea is covalently linked via a disulfide bond to type XII collagen.

    Science.gov (United States)

    Runager, Kasper; Klintworth, Gordon K; Karring, Henrik; Enghild, Jan J

    2013-04-23

    TGFBIp, also known as keratoepithelin and βig-h3, is among the most abundant proteins in the human cornea, and approximately 60% is associated with the insoluble fraction following extraction in sodium dodecyl sulfate (SDS) sample buffer. TGFBIp is of particular interest because a wide range of mutations causes amyloid or fuchsinophilic crystalloid deposits in the cornea leading to visual impairment. We show that the SDS-insoluble fraction of TGFBIp from porcine and human corneas is covalently linked via a reducible bond to the NC3 domain of type XII collagen in a TGFBIp:type XII collagen stoichiometric ratio of 2:1. Because type XII collagen is anchored to striated collagen fibers of the extracellular matrix, its interaction with TGFBIp is likely to provide anchoring for cells to the extracellular matrix through the integrin binding capability of TGFBIp. Furthermore, the TGFBIp-type XII collagen molecule will affect our understanding of the molecular pathogenesis of the TGFBI-linked corneal dystrophies.

  12. Subepithelial connective tissue graft with or without enamel matrix derivative for the treatment of Miller class I and II gingival recessions: a controlled randomized clinical trial.

    Science.gov (United States)

    Roman, A; Soancă, A; Kasaj, A; Stratul, S-I

    2013-10-01

    The aim of this study was to evaluate whether the combination of enamel matrix derivative (EMD) with subepithelial connective tissue graft (SCTG) plus coronally advanced flap (CAF) would improve the treatment outcomes of Miller class I and II gingival recessions when compared with the same technique (SCTG plus CAF) alone. The study was designed as a randomized, parallel, controlled, double-blinded clinical trial. Forty-two patients were randomly assigned in the test group (SCTG plus EMD) and in the control group (SCTG). Patients had at least one gingival recession ≥ 2 mm. The clinical parameters were evaluated at baseline and at 14 d, 1, 3, 6 and 12 mo follow-up time points. Forty-two patients, 21 in the test group (SCTG plus EMD) and 21 in the control group (SCTG), aged 21-48 years (mean age 31 ± 8.56) were initially included in the study. Both treatments, STCG plus EMD and SCTG, resulted in a significant final mean root coverage (2.91 ± 0.95mm and 2.91 ± 1.29 mm, respectively) (p < 0.001) and in a high mean percentage of root coverage (82.25 ± 22.20% and 89.75 ± 17.33%, respectively) (p < 0.001), 1 year after surgery. The differences in mean root coverage recorded for the two techniques after 1 year, were not statistically significant (p = 0.19). Complete root coverage was achieved in 56.5% of patients treated with SCTG plus EMD and in 70.6% of patients treated with SCTG (p = 0.275), 1 year after treatment. The present study failed to demonstrate any additional clinical benefits when EMD was added to SCTG plus CAF. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Expression of type XXIII collagen mRNA and protein.

    Science.gov (United States)

    Koch, Manuel; Veit, Guido; Stricker, Sigmar; Bhatt, Pinaki; Kutsch, Stefanie; Zhou, Peihong; Reinders, Elina; Hahn, Rita A; Song, Rich; Burgeson, Robert E; Gerecke, Donald R; Mundlos, Stefan; Gordon, Marion K

    2006-07-28

    Collagen XXIII is a member of the transmembranous subfamily of collagens containing a cytoplasmic domain, a membrane-spanning hydrophobic domain, and three extracellular triple helical collagenous domains interspersed with non-collagenous domains. We cloned mouse, chicken, and humanalpha1(XXIII) collagen cDNAs and showed that this non-abundant collagen has a limited tissue distribution in non-tumor tissues. Lung, cornea, brain, skin, tendon, and kidney are the major sites of expression. In contrast, five transformed cell lines were tested for collagen XXIII expression, and all expressed the mRNA. In vivo the alpha1(XXIII) mRNA is found in mature and developing organs, the latter demonstrated using stages of embryonic chick cornea and mouse embryos. Polyclonal antibodies were generated in guinea pig and rabbit and showed that collagen XXIII has a transmembranous form and a shed form. Comparison of collagen XXIII with its closest relatives in the transmembranous subfamily of collagens, types XIII and XXV, which have the same number of triple helical and non-collagenous regions, showed that there is a discontinuity in the alignment of domains but that striking similarities remain despite this.

  14. Preparation of (3H)collagen for studies of the biologic fate of xenogenic collagen implants in vivo

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, J.M.; Sawamura, S.J.; Conti, A.

    1986-06-01

    Reduction of a commercially available, pepsin-solubilized, bovine dermal collagen (Vitrogen 100) with sodium (3H)borohydride provided radiolabeled collagen preparations with specific activities ranging from 7.1-12.0 muCi/mg collagen. These specific activities were 2-3 times greater than those obtained by reduction of intact rat tail tendon collagen under similar conditions. The alpha, beta, and higher aggregate components of type I collagen were radiolabeled as well as the alpha component of a small amount of type III collagen present in the samples. Fractionation of cyanogen bromide peptides showed that alpha 1(I)CB7, alpha 1(I)CB8, and alpha 2(I)CB3,5 were the predominant peptides labeled by this procedure. Amino acid analysis indicated that the majority of the radioactivity was in reducible cross-links, precursors of these cross-links, and in hexosyllysine residues. Reconstitution experiments comparing this radiolabeled collagen with nonlabeled collagen showed them to be indistinguishable. Bacterial collagenase digestion of this reconstituted fibrillar collagen in both a lightly cross-linked (glutaraldehyde 0.0075%) and noncross-linked form provided evidence that digestion of labeled and nonlabeled collagens proceeded at similar rates. Thus, labeling did not change the properties of the collagen. Cross-linking made the preparation refractory to proteolytic degradation. Injection of fibrillar collagen preparations, spiked with radiolabeled collagen, into the guinea pig dermis followed by quantitation of the amount of radioactivity recovered from implant sites as a function of time, indicated that the lightly cross-linked samples also were more resistant to degradation in vivo than the noncross-linked preparation. The half-life of noncross-linked collagen was about 4 days while that of the cross-linked collagen was about 25 days.

  15. [Effect on keratocyte-mediated collagen degradation by Pseudomonas aeruginosa].

    Science.gov (United States)

    Hao, J; Lu, Y; Jia, H; Liu, J; Xu, J; Zhang, R

    2000-01-01

    To study the pathogenesis of cornea melting (ulceration) by pseudomona (P) aeruginosa for instruction of clinical treatment. Type I collagen gels with or without suspended keratocytes were incubated for 24 hours under medium containing sterile P. aeruginosa culture broth. Native collagen fibrils were removed from the media by ultrafiltration. The ultrafiltrates were then hydrolyzed, and the amount of hydroxyproline was measured spectrophotometrically. The effect of a synthetic matrix metalloproteinase (MMP) inhibitor, Galardin, on collagen degradation was also examined. P. aeruginosa broth induced type I collagen gel degradation directly. In the presence of keratocytes, degradation by P. aeruginosa broth was enhanced. Galardin significantly reduced the amount of collagen degraded by P. aeruginosa culture broth, no matter keratocytes were present or not. P. aeruginosa culture broth directly degrades type I collagen and also increases keratocyte-mediated collagen degradation. The result is helpful to the clinical treatment of cornea melting caused by P. aeruginosa, and the mechanism should be further studied.

  16. The non-phagocytic route of collagen uptake

    DEFF Research Database (Denmark)

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

    2011-01-01

    of these utilized uPARAP/Endo180 for their collagen uptake process. Macrophages internalized collagen in a process mediated by the mannose receptor, a protein belonging to the same protein family as uPARAP/Endo180. β1-Integrins were found not to be involved in the endocytosis of soluble collagen, irrespectively......-regulates the receptor protein level on treated cells, to examine the role of uPARAP/Endo180 as a mediator of collagen internalization by a wide range of cultured cell types. With the exception of macrophages, all cells that proved capable of efficient collagen internalization were of mesenchymal origin and all......The degradation of collagens, the most abundant proteins of the extracellular matrix, is involved in numerous physiological and pathological conditions including cancer invasion. An important turnover pathway involves cellular internalization and degradation of large, soluble collagen fragments...

  17. Transdermal Delivery of Functional Collagen Via Polyvinylpyrrolidone Microneedles

    Science.gov (United States)

    Sun, Wenchao; Inayathullah, Mohammed; Manoukian, Martin A. C.; Malkovskiy, Andrey V.; Manickam, Sathish; Marinkovich, M. Peter; Lane, Alfred T.; Tayebi, Lobat; Seifalian, Alexander M.; Rajadas, Jayakumar

    2017-01-01

    Collagen makes up a large proportion of the human body, particularly the skin. As the body ages, collagen content decreases, resulting in wrinkled skin and decreased wound healing capabilities. This paper presents a method of delivering type I collagen into porcine and human skin utilizing a polyvinylpyrrolidone microneedle delivery system. The microneedle patches were made with concentrations of 1, 2, 4, and 8% type I collagen (w/w). Microneedle structures and the distribution of collagen were characterized using scanning electron microscopy and confocal microscopy. Patches were then applied on the porcine and human skin, and their effectiveness was examined using fluorescence microscopy. The results illustrate that this microneedle delivery system is effective in delivering collagen I into the epidermis and dermis of porcine and human skin. Since the technique presented in this paper is quick, safe, effective and easy, it can be considered as a new collagen delivery method for cosmetic and therapeutic applications. PMID:26066056

  18. Transdermal Delivery of Functional Collagen Via Polyvinylpyrrolidone Microneedles.

    Science.gov (United States)

    Sun, Wenchao; Inayathullah, Mohammed; Manoukian, Martin A C; Malkovskiy, Andrey V; Manickam, Sathish; Marinkovich, M Peter; Lane, Alfred T; Tayebi, Lobat; Seifalian, Alexander M; Rajadas, Jayakumar

    2015-12-01

    Collagen makes up a large proportion of the human body, particularly the skin. As the body ages, collagen content decreases, resulting in wrinkled skin and decreased wound healing capabilities. This paper presents a method of delivering type I collagen into porcine and human skin utilizing a polyvinylpyrrolidone microneedle delivery system. The microneedle patches were made with concentrations of 1, 2, 4, and 8% type I collagen (w/w). Microneedle structures and the distribution of collagen were characterized using scanning electron microscopy and confocal microscopy. Patches were then applied on the porcine and human skin, and their effectiveness was examined using fluorescence microscopy. The results illustrate that this microneedle delivery system is effective in delivering collagen I into the epidermis and dermis of porcine and human skin. Since the technique presented in this paper is quick, safe, effective and easy, it can be considered as a new collagen delivery method for cosmetic and therapeutic applications.

  19. LARP6 Meets Collagen mRNA: Specific Regulation of Type I Collagen Expression

    Directory of Open Access Journals (Sweden)

    Yujie Zhang

    2016-03-01

    Full Text Available Type I collagen is the most abundant structural protein in all vertebrates, but its constitutive rate of synthesis is low due to long half-life of the protein (60–70 days. However, several hundred fold increased production of type I collagen is often seen in reparative or reactive fibrosis. The mechanism which is responsible for this dramatic upregulation is complex, including multiple levels of regulation. However, posttranscriptional regulation evidently plays a predominant role. Posttranscriptional regulation comprises processing, transport, stabilization and translation of mRNAs and is executed by RNA binding proteins. There are about 800 RNA binding proteins, but only one, La ribonucleoprotein domain family member 6 (LARP6, is specifically involved in type I collagen regulation. In the 5′untranslated region (5’UTR of mRNAs encoding for type I and type III collagens there is an evolutionally conserved stem-loop (SL structure; this structure is not found in any other mRNA, including any other collagen mRNA. LARP6 binds to the 5′SL in sequence specific manner to regulate stability of collagen mRNAs and their translatability. Here, we will review current understanding of how is LARP6 involved in posttranscriptional regulation of collagen mRNAs. We will also discuss how other proteins recruited by LARP6, including nonmuscle myosin, vimentin, serine threonine kinase receptor associated protein (STRAP, 25 kD FK506 binding protein (FKBP25 and RNA helicase A (RHA, contribute to this process.

  20. Collagens XV and XVIII show different expression and localisation in cutaneous squamous cell carcinoma: type XV appears in tumor stroma, while XVIII becomes upregulated in tumor cells and lost from microvessels.

    Science.gov (United States)

    Karppinen, Sanna-Maria; Honkanen, Hanne-Kaisa; Heljasvaara, Ritva; Riihilä, Pilvi; Autio-Harmainen, Helena; Sormunen, Raija; Harjunen, Vanessa; Väisänen, Marja-Riitta; Väisänen, Timo; Hurskainen, Tiina; Tasanen, Kaisa; Kähäri, Veli-Matti; Pihlajaniemi, Taina

    2016-05-01

    As the second most common skin malignancy, cutaneous squamous cell carcinoma (cSCC) is an increasing health concern, while its pathogenesis at molecular level remains largely unknown. We studied the expression and localisation of two homologous basement membrane (BM) collagens, types XV and XVIII, at different stages of cSCC. These collagens are involved in angiogenesis and tumorigenesis, but their role in cancer development is incompletely understood. Quantitative RT-PCR analysis revealed upregulation of collagen XVIII, but not collagen XV, in primary cSCC cells in comparison with normal human epidermal keratinocytes. In addition, the Ha-ras-transformed invasive cell line II-4 expressed high levels of collagen XVIII mRNA, indicating upregulation in the course of malignant transformation. Immunohistochemical analyses of a large human tissue microarray material showed that collagen XVIII is expressed by tumor cells from grade 1 onwards, while keratinocytes in normal skin and in premalignant lesions showed negative staining for it. Collagen XV appeared instead as deposits in the tumor stroma. Our findings in human cSCCs and in mouse cSCCs from the DMBA-TPA skin carcinogenesis model showed that collagen XVIII, but not collagen XV or the BM markers collagen IV or laminin, was selectively reduced in the tumor vasculature, and this decrease associated significantly with cancer progression. Our results demonstrate that collagens XV and XVIII are expressed in different sites of cSCC and may contribute in a distinct manner to processes related to cSCC tumorigenesis, identifying these collagens as potential biomarkers in the disease. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Live Imaging of Type I Collagen Assembly Dynamics in Osteoblasts Stably Expressing GFP and mCherry-tagged Collagen Constructs.

    Science.gov (United States)

    Lu, Yongbo; Sayed, Suzan A Kamel-El; Wang, Kun; Tiede-Lewis, LeAnn M; Grillo, Michael A; Veno, Patricia A; Dusevich, Vladimir; Phillips, Charlotte L; Bonewald, Lynda F; Dallas, Sarah L

    2018-02-20

    Type I collagen is the most abundant extracellular matrix protein in bone and other connective tissues and plays key roles in normal and pathological bone formation as well as in connective tissue disorders and fibrosis. Although much is known about the collagen biosynthetic pathway and its regulatory steps, the mechanisms by which it is assembled extracellularly are less clear. We have generated GFPtpz and mCherry-tagged collagen fusion constructs for live imaging of type I collagen assembly by replacing the α2(I)-procollagen N-terminal propeptide with GFPtpz or mCherry. These novel imaging probes were stably transfected into MLO-A5 osteoblast-like cells and fibronectin-null mouse embryonic fibroblasts (FN-null-MEFs) and used for imaging type I collagen assembly dynamics and its dependence on fibronectin. Both fusion proteins co-precipitated with α1(I)-collagen and remained intracellular without ascorbate but were assembled into α1(I) collagen-containing extracellular fibrils in the presence of ascorbate. Immunogold-EM confirmed their ultrastuctural localization in banded collagen fibrils. Live cell imaging in stably-transfected MLO-A5 cells revealed the highly dynamic nature of collagen assembly and showed that during assembly the fibril networks are continually stretched and contracted due to the underlying cell motion. We also observed that cell-generated forces can physically reshape the collagen fibrils. Using co-cultures of mCherry- and GFPtpz-collagen expressing cells we show that multiple cells contribute collagen to form collagen fiber bundles. ImmunoEM further showed that individual collagen fibrils can receive contributions of collagen from more than one cell. Live cell imaging in FN-null-MEFs expressing GFPtpz-collagen showed that collagen assembly was both dependent upon and dynamically integrated with fibronectin assembly. These GFP-collagen fusion constructs provide a powerful tool for imaging collagen in living cells and have revealed novel and

  2. Collagen-collagen interactions mediated by plant-derived proanthocyanidins: A spectroscopic and atomic force microscopy study.

    Science.gov (United States)

    Vidal, Cristina M P; Zhu, Weiying; Manohar, Suresh; Aydin, Berdan; Keiderling, Timothy A; Messersmith, Phillip B; Bedran-Russo, Ana K

    2016-09-01

    Collagen cross-linkings are determinant of biological tissue stability and function. Plant-derived proanthocyanidins (PACs) mimic different hierarchical levels of collagen cross-links by non-enzymatic interactions resulting in the enhancement to the biomechanics and biostability of collagen-rich tissues such as dentin. This study investigated the interaction of PACs from Vitis vinifera grape seed extract with type I collagen in solubilized form and in the demineralized dentin matrix (DDM) by fluorescence spectral analysis; collagen-collagen binding forces in presence of cross-linking solutions by atomic force microscopy (AFM); and spectroscopic analysis of the DDM using attenuated total reflectance Fourier transform-infrared spectroscopy (ATR-FTIR). Glutaraldehyde (GA) and carbodiimide hydrochloride (EDC) with known cross-linking mechanisms were selected for comparative analyses. Changes in fluorescence upon interaction of solubilized type I collagen with PACs, EDC and GA reflected pronounced modifications in collagen conformation. PACs also promoted stronger collagen-collagen fibrils interaction than EDC and GA. A new feature was observed using ATR-FTIR spectroscopic analysis in PACs-treated collagen and DDM. The findings suggest covalent interactions between collagen and PACs. The mechanisms of interaction between PACs-collagen hold attractive and promising tissue-tailored biomedical applications and the binding forces that potentially drive such interaction were characterized. Connective tissues such as skin, bone and dentin are mainly composed of type I collagen, which is cross-linked to promote tissue stability, strength and function. Novel therapies using substances that mimic cross-links have been proposed to promote repair of collagen-based-tissues. In dentistry, naturally occurring proanthocyanidins (PACs) have the potential to enhance dentin mechanical properties and reduce its enzymatic degradation, but their mechanisms of cross-linking are unclear. The

  3. Strain stiffening in collagen I networks.

    Science.gov (United States)

    Motte, Stéphanie; Kaufman, Laura J

    2013-01-01

    Biopolymer gels exhibit strain stiffening that is generally not seen in synthetic gels. Here, we investigate the strain-stiffening behavior in collagen I gels that demonstrate elasticity derived from a variety of sources including crosslinking through telopeptides, bundling through low-temperature gelation, and exogenous crosslinking with genipin. In all cases, it is found that these gels exhibit strain stiffening; in general, onset of strain stiffening occurs earlier, yield strain is lower, and degree of strain stiffening is smaller in higher concentration gels and in those displaying thick fibril bundles. Recovery after exposure to high strains is substantial and similar in all gels, suggesting that much of the stiffening comes from reversible network deformations. A key finding of this study is that collagen I gels of identical storage and loss moduli may display different nonlinear responses and different capacities to recover from high strain. Copyright © 2012 Wiley Periodicals, Inc.

  4. [Corneal collagen cross-linking for keratoconus].

    Science.gov (United States)

    Zotov, V V; Pashtaev, N P; Pozdeeva, N A

    2015-01-01

    Over the last decade, corneal collagen cross-linking (CXL) has become a conventional treatment method for progressive keratoconus. Laboratory studies have shown that CXL increases the diameter of collagen fibers and also the number of intra- and interfibrillar cross-links, thus, increasing biomechanical strength of the irradiated cornea. As confirmed by a series of clinical and randomized controlled trials, CXL is able to slow down and, perhaps, to stop the progression of keratoconus. In most post-CXL patients visual acuity improves, while keratometric readings, spherical equivalent, and higher order aberrations reduce. Although published results prove CXL effective in the treatment of progressive keratoconus, its late consequences are yet unknown. This article reviews the stages of CXL development and results of published experimental and clinical studies. Prospects for CXL modifications that do not require epithelial debridement are discussed.

  5. Corneal collagen cross-linking for treating keratoconus.

    Science.gov (United States)

    Sykakis, Evripidis; Karim, Rushmia; Evans, Jennifer R; Bunce, Catey; Amissah-Arthur, Kwesi N; Patwary, Showrob; McDonnell, Peter J; Hamada, Samer

    2015-03-24

    Keratoconus is a condition of the eye that affects approximately 1 in 2000 people. The disease leads to a gradual increase in corneal curvature and decrease in visual acuity with consequent impact on quality of life. Collagen cross-linking (CXL) with ultraviolet A (UVA) light and riboflavin (vitamin B2) is a relatively new treatment that has been reported to slow or halt the progression of the disease in its early stages. The objective of this review was to assess whether there is evidence that CXL is an effective and safe treatment for halting the progression of keratoconus compared to no treatment. We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 7), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to August 2014), EMBASE (January 1980 to August 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (1982 to August 2014), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to August 2014), OpenGrey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organisation International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We used no date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 28 August 2014. We included randomised controlled trials (RCTs) where CXL with UVA light and riboflavin was used to treat people with keratoconus and was compared to no treatment. Two review authors independently screened the search results, assessed trial quality, and extracted data using standard methodological procedures expected by Cochrane. Our primary outcomes were two indicators of progression at 12 months: increase in maximum keratometry of 1.5 dioptres (D) or more and

  6. Corneal Collagen Cross-Linking Outcomes: Review

    OpenAIRE

    Jankov II,Mirko R.; Jovanovic,Vesna; Delevic, Sladjana; Coskunseven, Efekan

    2011-01-01

    Keratoconus is a condition characterized by biomechanical instability of the cornea, presenting in a progressive, asymmetric and bilateral way. Corneal collagen cross-linking with riboflavin and UVA (CXL) is a new technique of corneal tissue strengthening that combines the use of riboflavin as a photo sensitizer and UVA irradiation. The studies showed that CXL was effective in halting the progression of keratoconus over a period of up to four years. The published studies also revealed a reduc...

  7. Osteoinduction and proliferation of bone-marrow stromal cells in three-dimensional poly (ε-caprolactone)/ hydroxyapatite/collagen scaffolds.

    Science.gov (United States)

    Wang, Ting; Yang, Xiaoyan; Qi, Xin; Jiang, Chaoyin

    2015-05-08

    Osteoinduction and proliferation of bone-marrow stromal cells (BMSCs) in three-dimensional (3D) poly(ε-caprolactone) (PCL) scaffolds have not been studied throughly and are technically challenging. This study aimed to optimize nanocomposites of 3D PCL scaffolds to provide superior adhesion, proliferation and differentiation environment for BMSCs in this scenario. BMSCs were isolated and cultured in a novel 3D tissue culture poly(ε-caprolactone) (PCL) scaffold coated with poly-lysine, hydroxyapatite (HAp), collagen and HAp/collagen. Cell morphology was observed and BMSC biomarkers for osteogenesis, osteoblast differentiation and activation were analyzed. Scanning Electron Microscope (SEM) micrographs showed that coating materials were uniformly deposited on the surface of PCL scaffolds and BMSCs grew and aggregated to form clusters during 3D culture. Both mRNA and protein levels of the key players of osteogenesis and osteoblast differentiation and activation, including runt-related transcription factor 2 (Runx2), alkaline phosphates (ALP), osterix, osteocalcin, and RANKL, were significantly higher in BMSCs seeded in PCL scaffolds coated with HAp or HAp/collagen than those seeded in uncoated PCL scaffolds, whereas the expression levels were not significantly different in collagen or poly-lysine coated PCL scaffolds. In addition, poly-lysine, collagen, HAp/collagen, and HAp coated PCL scaffolds had significantly more viable cells than uncoated PCL scaffolds, especially scaffolds with HAp/collagen and collagen-alone coatings. That BMSCs in HAp or HAp/collagen PCL scaffolds had remarkably higher ALP activities than those in collagen-coated alone or uncoated PCL scaffolds indicating higher osteogenic differentiation levels of BMSCs in HAp or HAp/collagen PCL scaffolds. Moreover, morphological changes of BMSCs after four-week of 3D culture confirmed that BMSCs successfully differentiated into osteoblast with spread-out phenotype in HAp/collagen coated PCL scaffolds

  8. Abnormal Type I Collagen Post-translational Modification and Crosslinking in a Cyclophilin B KO Mouse Model of Recessive Osteogenesis Imperfecta

    Science.gov (United States)

    Cabral, Wayne A.; Perdivara, Irina; Weis, MaryAnn; Terajima, Masahiko; Blissett, Angela R.; Chang, Weizhong; Perosky, Joseph E.; Makareeva, Elena N.; Mertz, Edward L.; Leikin, Sergey; Tomer, Kenneth B.; Kozloff, Kenneth M.; Eyre, David R.; Yamauchi, Mitsuo; Marini, Joan C.

    2014-01-01

    crosslink pattern was associated with decreased collagen deposition into matrix in culture, altered fibril structure in tissue, and reduced bone strength. These studies demonstrate novel consequences of the indirect regulatory effect of CyPB on collagen hydroxylation, impacting collagen glycosylation, crosslinking and fibrillogenesis, which contribute to maintaining bone mechanical properties. PMID:24968150

  9. Mechanical Behavior of Collagen-Fibrin Co-Gels Reflects Transition From Series to Parallel Interactions With Increasing Collagen Content

    Science.gov (United States)

    Lai, Victor K.; Lake, Spencer P.; Frey, Christina R.; Tranquillo, Robert T.; Barocas, Victor H.

    2012-01-01

    Fibrin and collagen, biopolymers occurring naturally in the body, are biomaterials commonly-used as scaffolds for tissue engineering. How collagen and fibrin interact to confer macroscopic mechanical properties in collagen-fibrin composite systems remains poorly understood. In this study, we formulated collagen-fibrin co-gels at different collagen-tofibrin ratios to observe changes in the overall mechanical behavior and microstructure. A modeling framework of a two-network system was developed by modifying our micro-scale model, considering two forms of interaction between the networks: (a) two interpenetrating but noninteracting networks (“parallel”), and (b) a single network consisting of randomly alternating collagen and fibrin fibrils (“series”). Mechanical testing of our gels show that collagen-fibrin co-gels exhibit intermediate properties (UTS, strain at failure, tangent modulus) compared to those of pure collagen and fibrin. The comparison with model predictions show that the parallel and series model cases provide upper and lower bounds, respectively, for the experimental data, suggesting that a combination of such interactions exists between the collagen and fibrin in co-gels. A transition from the series model to the parallel model occurs with increasing collagen content, with the series model best describing predominantly fibrin co-gels, and the parallel model best describing predominantly collagen co-gels. PMID:22482659

  10. Chemical Stabilisation of Collagen as a Biomimetic

    Directory of Open Access Journals (Sweden)

    R. Gordon Paul

    2003-01-01

    Full Text Available Collagen is the most abundant protein in animals and because of its high mechanical strength and good resistance to degradation has been utilized in a wide range of products in industry whilst its low antigenicity has resulted in its widespread use in medicine. Collagen products can be purified from fibres, molecules reconstituted as fibres or from specific recombinant polypeptides with preferred properties. A common feature of all these biomaterials is the need for stable chemical cross-linking to control the mechanical properties and the residence time in the body, and to some extent the immunogenicity of the device. This can be achieved by a number of different cross-linking agents that react with specific amino acid residues on the collagen molecule imparting individual biochemical, thermal and mechanical characteristics to the biomaterial. In this review we have summarised the major techniques for testing these characteristics and the mechanisms involved in the variety of cross-linking reactions to achieve particular properties..

  11. Cross-Linked Collagen Triple Helices by Oxime Ligation.

    Science.gov (United States)

    Hentzen, Nina B; Smeenk, Linde E J; Witek, Jagna; Riniker, Sereina; Wennemers, Helma

    2017-09-13

    Covalent cross-links are crucial for the folding and stability of triple-helical collagen, the most abundant protein in nature. Cross-linking is also an attractive strategy for the development of synthetic collagen-based biocompatible materials. Nature uses interchain disulfide bridges to stabilize collagen trimers. However, their implementation into synthetic collagen is difficult and requires the replacement of the canonical amino acids (4R)-hydroxyproline and proline by cysteine or homocysteine, which reduces the preorganization and thereby stability of collagen triple helices. We therefore explored alternative covalent cross-links that allow for connecting triple-helical collagen via proline residues. Here, we present collagen model peptides that are cross-linked by oxime bonds between 4-aminooxyproline (Aop) and 4-oxoacetamidoproline placed in coplanar Xaa and Yaa positions of neighboring strands. The covalently connected strands folded into hyperstable collagen triple helices (Tm ≈ 80 °C). The design of the cross-links was guided by an analysis of the conformational properties of Aop, studies on the stability and functionalization of Aop-containing collagen triple helices, and molecular dynamics simulations. The studies also show that the aminooxy group exerts a stereoelectronic effect comparable to fluorine and introduce oxime ligation as a tool for the functionalization of synthetic collagen.

  12. Collagen immobilization on polyethylene terephthalate surface after helium plasma treatment

    Energy Technology Data Exchange (ETDEWEB)

    Aflori, Magdalena, E-mail: maflori@icmpp.ro [Department of Polymers Physics and Polymeric Materials, “Petru Poni” Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Drobota, Mioara [Department of Polymers Physics and Polymeric Materials, “Petru Poni” Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Dimitriu, Dan Gh. [Faculty of Physics, “Alexandru Ioan Cuza” University, 20A Bulevardul Carol I, 700505 Iasi (Romania); Stoica, Iuliana [Department of Polymers Physics and Polymeric Materials, “Petru Poni” Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, 700487 Iasi (Romania); Simionescu, Bogdana [Department of Polymers Physics and Polymeric Materials, “Petru Poni” Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, 700487 Iasi (Romania); “Costin D. Nenitescu” Centre of Organic Chemistry, 202B Splaiul Independentei, 71141 Bucharest (Romania); Harabagiu, Valeria [Department of Polymers Physics and Polymeric Materials, “Petru Poni” Institute of Macromolecular Chemistry, 41A Gr. Ghica Voda Alley, 700487 Iasi (Romania)

    2013-11-20

    An attractive alternative to add new functionalities such as biocompatibility due to the micro- and nano-scaled modification of polymer surfaces is offered by plasma processing. Many vital processes of tissue repair and growth following injuries depend on the rate of adsorption and self-assembling of the collagen molecules at the interfaces. Consequently, besides the amount of protein, it is necessary to investigate the form in which the collagen molecules are organizing on the polymer surface. In this study, direct current (DC) helium plasma treatment was used in order to obtain poly(ethylene terephthalate) (PET) films with different amounts of collagen and different shapes of aggregates formed from the collagen molecules. The immobilization of collagen on PET surface was confirmed by XPS measurements, an increase of the nitrogen content by increasing the plasma exposure time being recorded. The SEM and AFM measurements revealed the presence of grains and dendrites of collagen formed on the polymer surface. At 15 min plasma treatment time, the polymer surface after collagen immobilization has a homogenous topography. Usually, one can find fibrils, coil or dendrimers of collagen formed in buffer solutions and immobilized on different polymer surfaces. On the other hand, in this particular configuration, the combination of DC plasma and helium gas as a PET functionalization tool is an original one. As the collagen is not covalently immobilized on the surfaces, it may interact with the cell culture medium proteins, part of the collagen might being replaced by other serum proteins.

  13. Collagens and proteoglycans of the corneal extracellular matrix

    Directory of Open Access Journals (Sweden)

    Y.M. Michelacci

    2003-08-01

    Full Text Available The cornea is a curved and transparent structure that provides the initial focusing of a light image into the eye. It consists of a central stroma that constitutes 90% of the corneal depth, covered anteriorly with epithelium and posteriorly with endothelium. Its transparency is the result of the regular spacing of collagen fibers with remarkably uniform diameter and interfibrillar space. Corneal collagen is composed of heterotypic fibrils consisting of type I and type V collagen molecules. The cornea also contains unusually high amounts of type VI collagen, which form microfibrillar structures, FACIT collagens (XII and XIV, and other nonfibrillar collagens (XIII and XVIII. FACIT collagens and other molecules, such as leucine-rich repeat proteoglycans, play important roles in modifying the structure and function of collagen fibrils.Proteoglycans are macromolecules composed of a protein core with covalently linked glycosaminoglycan side chains. Four leucine-rich repeat proteoglycans are present in the extracellular matrix of corneal stroma: decorin, lumican, mimecan and keratocan. The first is a dermatan sulfate proteoglycan, and the other three are keratan sulfate proteoglycans. Experimental evidence indicates that the keratan sulfate proteoglycans are involved in the regulation of collagen fibril diameter, and dermatan sulfate proteoglycan participates in the control of interfibrillar spacing and in the lamellar adhesion properties of corneal collagens. Heparan sulfate proteoglycans are minor components of the cornea, and are synthesized mainly by epithelial cells. The effect of injuries on proteoglycan synthesis is discussed.

  14. Collagen tissue engineering: development of novel biomaterials and applications.

    Science.gov (United States)

    Cen, Lian; Liu, Wei; Cui, Lei; Zhang, Wenjie; Cao, Yilin

    2008-05-01

    Scientific investigations involving collagen have inspired tissue engineering and design of biomaterials since collagen fibrils and their networks primarily regulate and define most tissues. The collagen networks form a highly organized, three-dimensional architecture to entrap other ingredients. Biomaterials are expected to function as cell scaffolds to replace native collagen-based extracellular matrix. The composition and properties of biomaterials used as scaffold for tissue engineering significantly affect the regeneration of neo-tissues and influence the conditions of collagen engineering. The complex scenario of collagen characteristics, types, fibril arrangement, and collagen structure-related functions (in a variety of connective tissues including bone, cartilage, tendon, skin and cornea) are addressed in this review. Discussion will focus on nanofibrillar assemblies and artificial synthetic peptides that mimic either the fibrillar structure or the elemental components of type I collagen as illustrated by their preliminary applications in tissue engineering. Conventional biomaterials used as scaffolds in engineering collagen-containing tissues are also discussed. The design of novel biomaterials and application of conventional biomaterials will facilitate development of additional novel tissue engineering bioproducts by refining the currently available techniques. The field of tissue engineering will ultimately be advanced by increasing control of collagen in native tissue and by continual manipulation of biomaterials.

  15. Binding of collagens to an enterotoxigenic strain of Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Visai, L.; Speziale, P.; Bozzini, S. (Univ. of Pavia (Italy))

    1990-02-01

    An enterotoxigenic strain of Escherichia coli, B34289c, has been shown to bind the N-terminal region of fibronectin with high affinity. We now report that this strain also binds collagen. The binding of 125I-labeled type II collagen to bacteria was time dependent and reversible. Bacteria expressed a limited number of collagen receptors (2.2 x 10(4) per cell) and bound collagen with a Kd of 20 nM. All collagen types tested (I to V) as well as all tested cyanogen bromide-generated peptides (alpha 1(I)CB2, alpha 1(I)CB3, alpha 1(I)CB7, alpha 1(I)CB8, and alpha 2(I)CB4) were recognized by bacterial receptors, as demonstrated by the ability of these proteins to inhibit the binding of 125I-labeled collagen to bacteria. Of several unlabeled proteins tested in competition experiments, fibronectin and its N-terminal region strongly inhibited binding of the radiolabeled collagen to E. coli cells. Conversely, collagen competed with an 125I-labeled 28-kilodalton fibronectin fragment for bacterial binding. Collagen bound to bacteria could be displaced by excess amounts of either unlabeled fibronectin or its N-terminal fragment. Similarly, collagen could displace 125I-labeled N-terminal peptide of fibronectin bound to the bacterial cell surface. Bacteria grown at 41 degrees C or in the presence of glucose did not express collagen or fibronectin receptors. These results indicate the presence of specific binding sites for collagen on the surface of E. coli cells and furthermore that the collagen and fibronectin binding sites are located in close proximity, possibly on the same structure.

  16. ISOCT study of collagen crosslinking of collagen in cancer models (Conference Presentation)

    Science.gov (United States)

    Spicer, Graham; Young, Scott T.; Yi, Ji; Shea, Lonnie D.; Backman, Vadim

    2016-03-01

    The role of extracellular matrix modification and signaling in cancer progression is an increasingly recognized avenue for the progression of the disease. Previous study of field effect carcinogenesis with Inverse Spectroscopic Optical Coherence Tomography (ISOCT) has revealed pronounced changes in the nanoscale-sensitive mass fractal dimension D measured from field effect tissue when compared to healthy tissue. However, the origin of this difference in tissue ultrastructure in field effect carcinogenesis has remained poorly understood. Here, we present findings supporting the idea that enzymatic crosslinking of the extracellular matrix is an effect that presents at the earliest stages of carcinogenesis. We use a model of collagen gel with crosslinking induced by lysyl oxidase (LOXL4) to recapitulate the difference in D previously reported from healthy and cancerous tissue biopsies. Furthermore, STORM imaging of this collagen gel model verifies the morphologic effects of enzymatic crosslinking at length scales as small as 40 nm, close to the previously reported lower length scale sensitivity threshold of 35 nm for ISOCT. Analysis of the autocorrelation function from STORM images of collagen gels and subsequent fitting to the Whittle-Matérn correlation function shows a similar effect of LOXL4 on D from collagen measured with ISOCT and STORM. We extend this to mass spectrometric study of tissue to directly measure concentrations of collagen crosslink residues. The validation of ISOCT as a viable tool for non-invasive rapid quantification of collagen ultrastructure lends it to study other physiological phenomena involving ECM restructuring such as atherosclerotic plaque screening or cervical ripening during pregnancy.

  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

    Collagen is the principal tensile clement of the extra-cellular matrix in mammals and is the basic scaffold for cells and tissues. Collagen molecules are comprised of homo-trimeric helices (e.g. collagen type II and type III), ABB type hetero-trimeric helices (e.g. collagen type I, type IV, and type V), or ABC type hetero-trimeric helices (e.g. type V). Mimicry of collagen structures can help elucidate collagen triple helical conformation and provide insights into making novel collagen-like biomaterials. Our group previously reported a new physical collagen modification method, which was based on non-covalent interaction between collagen mimetic peptide (CMP: -(Pro-Hyp-Gly) x-) and natural collagen. We hypothesized that CMP binds to collagen through a process involving both strand invasion and triple helix assembly. The aim of this dissertation is to study structural formation and stability of collagen triple helix, and to investigate CMP-collagen binding interactions using two types of CMP derivatives: covalently templated CMP trimer and CMP-nanoparticle conjugates. We demonstrated that covalently templated ABB type CMP hetero-trimers could be prepared by a versatile synthetic strategy involving both solid phase and solution peptide coupling. Our thermal melting studies showed that the templated CMP hetero-trimers formed collagen-like triple helices and their folding kinetics correlated with the amino acid compositions of the individual CMP strands. We also studied the thermal melting behavior and folding kinetics of a templated hetero-trimer complex comprised of CMP and a peptide derived from collagen. This synthetic strategy can be readily extended to synthesize other ABB type hetero-trimers to investigate their local melting behavior and biological activity. We also prepared colloidally stable CMP functionalized gold nanoparticles (Au-CMPs) as a TEM marker for investigating the CMP-collagen interaction. Au-CMP showed preferential binding to collagen fiber's gap

  18. Microfibrous {beta}-TCP/collagen scaffolds mimic woven bone in structure and composition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Shen; Zhang Xin; Cai Qing; Yang Xiaoping [Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Wang Bo; Deng Xuliang, E-mail: yangxp@mail.buct.edu.c [Department of VIP Dental Service, School and Hospital of Stomatology, Peking University, Beijing 100081 (China)

    2010-12-15

    Woven bone, as the initial form of bone tissue, is always found in developing and repairing bone. It is thought of as a temporary scaffold for the deposition of osteogenic cells and the laying down of lamellar bone. Thus, we hypothesize that a matrix which resembles the architecture and components of woven bone can provide an osteoblastic microenvironment for bone cell growth and new bone formation. In this study, woven-bone-like beta-tricalcium phosphate ({beta}-TCP)/collagen scaffolds were fabricated by sol-gel electrospinning and impregnating methods. Optimization studies on sol-gel synthesis and electrospinning process were conducted respectively to prepare pure {beta}-TCP fibers with dimensions close to mineralized collagen fibrils in woven bone. The collagen-coating layer prepared by impregnation had an adhesive role that held the {beta}-TCP fibers together, and resulted in rapid degradation and matrix mineralization in in vitro tests. MG63 osteoblast-like cells seeded on the resultant scaffolds showed three-dimensional (3D) morphologies, and merged into multicellular layers after 7 days culture. Cytotoxicity test further revealed that extracts from the resultant scaffolds could promote the proliferation of MG63 cells. Therefore, the woven-bone-like matrix that we constructed favored the attachment and proliferation of MG63 cells in three dimensions. It has great potential ability to shorten the time of formation of new bone.

  19. The generation of biomolecular patterns in highly porous collagen-GAG scaffolds using direct photolithography.

    Science.gov (United States)

    Martin, Teresa A; Caliari, Steven R; Williford, Paul D; Harley, Brendan A; Bailey, Ryan C

    2011-06-01

    The extracellular matrix (ECM) is a complex organization of structural proteins found within tissues and organs. Heterogeneous tissues with spatially and temporally modulated properties play an important role in organism physiology. Here we present a benzophenone (BP) based direct, photolithographic approach to spatially pattern solution phase biomolecules within collagen-GAG (CG) scaffolds and demonstrate creation of a wide range of patterns composed of multiple biomolecular species in a manner independent from scaffold fabrication steps. We demonstrate the ability to immobilize biomolecules at surface densities of up to 1000 ligands per square micron on the scaffold strut surface and to depths limited by the penetration depth of the excitation source into the scaffold structure. Importantly, while BP photopatterning does further crosslink the CG scaffold, evidenced by increased mechanical properties and collagen crystallinity, it does not affect scaffold microstructural or compositional properties or negatively influence cell adhesion, viability, or proliferation. We show that covalently photoimmobilized fibronectin within a CG scaffold significantly increases the speed of MC3T3-E1 cell attachment relative to the bare CG scaffold or non-specifically adsorbed fibronectin, suggesting that this approach can be used to improve scaffold bioactivity. Our findings, on the whole, establish the use of direct, BP photolithography as a methodology for covalently incorporating activity-improving biochemical cues within 3D collagen biomaterial scaffolds with spatial control over biomolecular deposition. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Development of a reconstructed cornea from collagen-chondroitin sulfate foams and human cell cultures.

    Science.gov (United States)

    Vrana, N Engin; Builles, Nicolas; Justin, Virginie; Bednarz, Jurgen; Pellegrini, Graziella; Ferrari, Barbara; Damour, Odile; Hulmes, David J S; Hasirci, Vasif

    2008-12-01

    To develop an artificial cornea, the ability to coculture the different cell types present in the cornea is essential. Here the goal was to develop a full-thickness artificial cornea using an optimized collagen-chondroitin sulfate foam, with a thickness close to that of human cornea, by coculturing human corneal epithelial and stromal cells and transfected human endothelial cells. Corneal extracellular matrix was simulated by a porous collagen/glycosaminoglycan-based scaffold seeded with stromal keratocytes and then, successively, epithelial and endothelial cells. Scaffolds were characterized for bulk porosity and pore size distribution. The performance of the three-dimensional construct was studied by histology, immunofluorescence, and immunohistochemistry. The scaffold had 85% porosity and an average pore size of 62.1 microm. Keratocytes populated the scaffold and produced a newly synthesized extracellular matrix as characterized by immunohistochemistry. Even though the keratocytes lost their CD34 phenotype marker, the absence of smooth muscle actin fibers showed that these cells had not differentiated into myofibroblasts. The epithelial cells formed a stratified epithelium and began basement membrane deposition. An endothelial cell monolayer beneath the foam was also apparent. These results demonstrate that collagen-chondroitin sulfate scaffolds are good substrates for artificial cornea construction with good resilience, long-term culture capability, and handling properties.

  1. Osteoblasts extracellular matrix induces vessel like structures through glycosylated collagen I

    Energy Technology Data Exchange (ETDEWEB)

    Palmieri, D. [Genetics, DIBIO, University of Genova, Corso Europa 26, 16132 Genova (Italy); Valli, M.; Viglio, S. [Department of Biochemistry, University of Pavia (Italy); Ferrari, N. [Istituto Nazionale per la ricerca sul Cancro, Genova (Italy); Ledda, B.; Volta, C. [Genetics, DIBIO, University of Genova, Corso Europa 26, 16132 Genova (Italy); Manduca, P., E-mail: man-via@unige.it [Genetics, DIBIO, University of Genova, Corso Europa 26, 16132 Genova (Italy)

    2010-03-10

    Extracellular matrix (ECM) plays a fundamental role in angiogenesis affecting endothelial cells proliferation, migration and differentiation. Vessels-like network formation in vitro is a reliable test to study the inductive effects of ECM on angiogenesis. Here we utilized matrix deposed by osteoblasts as substrate where the molecular and structural complexity of the endogenous ECM is preserved, to test if it induces vessel-like network formation by endothelial cells in vitro. ECM is more similar to the physiological substrate in vivo than other substrates previously utilized for these studies in vitro. Osteogenic ECM, prepared in vitro from mature osteoblasts at the phase of maximal deposition and glycosylation of collagen I, induces EAhy926, HUVEC, and HDMEC endothelial cells to form vessels-like structures and promotes the activation of metalloproteinase-2 (MMP-2); the functionality of the p-38/MAPK signaling pathway is required. Osteogenic ECM also induces a transient increase of CXCL12 and a decrease of the receptor CXCR4. The induction of vessel-like networks is dependent from proper glycosylation of collagens and does not occur on osteogenic ECMs if deglycosylated by -galactosidase or on less glycosylated ECMs derived from preosteoblasts and normal fibroblasts, while is sustained on ECM from osteogenesis imperfecta fibroblasts only when their mutation is associated with over-glycosylation of collagen type I. These data support that post-translational glycosylation has a role in the induction in endothelial cells in vitro of molecules conductive to self-organization in vessels-like structures.

  2. Deposit model for volcanogenic uranium deposits

    Science.gov (United States)

    Breit, George N.; Hall, Susan M.

    2011-01-01

    Volcanism is a major contributor to the formation of important uranium deposits both close to centers of eruption and more distal as a result of deposition of ash with leachable uranium. Hydrothermal fluids that are driven by magmatic heat proximal to some volcanic centers directly form some deposits. These fluids leach uranium from U-bearing silicic volcanic rocks and concentrate it at sites of deposition within veins, stockworks, breccias, volcaniclastic rocks, and lacustrine caldera sediments. The volcanogenic uranium deposit model presented here summarizes attributes of those deposits and follows the focus of the International Atomic Energy Agency caldera-hosted uranium deposit model. Although inferred by some to have a volcanic component to their origin, iron oxide-copper-gold deposits with economically recoverable uranium contents are not considered in this model.

  3. [Clinicopathologic features of collagenous spherulosis of the breast].

    Science.gov (United States)

    Li, Jing; Yang, Guang-zhi; Jin, Hua; Ding, Hua-ye

    2013-11-01

    To investigate the morphological features, immunohistochemical phenotype, diagnosis and differential diagnosis of collagenous spherulosis of the breast. Clinicopathologic observation, immunohistochemistry using EnVision method and histochemical staining were applied in 33 cases of collagenous spherulosis of the breast. Collagenous spherulosis of the breast was a benign lesion, consisting of proliferative myoepithelial and ductal epithelial cells. These cells were arranged in a cribriform pattern with esinophilic, round, oval or star-shaped fibrillary spherules in the lumen.SMA, calponin and p63 by immunohistochemistry identified the proliferative myoepithelium, while E-cadherin identified the proliferative ductal epithelial cells. The esinophilic spherules were stained with collagen type IV, AB-PAS and reticulin. Collagenous spherulosis was often found in sclerosing adenosis. Collagenous spherulosis of the breast is often associated with other diseases. It has special morphological presentation and is easily confused with malignant tumors such as adenoid cystic carcinoma or cribriform carcinoma in situ, and needs to be differentiated from these disease entities.

  4. Collagen-silica xerogel nanohybrid membrane for guided bone regeneration.

    Science.gov (United States)

    Lee, Eun-Jung; Jun, Shin-Hee; Kim, Hyoun-Ee; Koh, Young-Hag

    2012-04-01

    A collagen-silica xerogel hybrid membrane was fabricated by a sol-gel process for guided bone regeneration (GBR). The silica xerogel synthesized by the sol-gel method was distributed uniformly within the collagen matrix in the form of nanoparticles. The hybridization of the silica xerogel with collagen improved the biological properties of the membrane significantly. Preosteoblast cells were observed to adhere well and grow much more actively on the hybrid membrane than on the pure collagen membrane. In particular, the hybrid membrane containing 30% of the silica xerogel showed the highest level of osteoblast differentiation. Moreover, the GBR ability, as assessed by the in vivo animal test, was superior to that of the pure collagen membrane. These findings suggest that the collagen-silica xerogel hybrid can be used as a GBR membrane. Copyright © 2012 Wiley Periodicals, Inc.

  5. Mineralized Collagen: Rationale, Current Status, and Clinical Applications

    Directory of Open Access Journals (Sweden)

    Zhi-Ye Qiu

    2015-07-01

    Full Text Available This paper presents a review of the rationale for the in vitro mineralization process, preparation methods, and clinical applications of mineralized collagen. The rationale for natural mineralized collagen and the related mineralization process has been investigated for decades. Based on the understanding of natural mineralized collagen and its formation process, many attempts have been made to prepare biomimetic materials that resemble natural mineralized collagen in both composition and structure. To date, a number of bone substitute materials have been developed based on the principles of mineralized collagen, and some of them have been commercialized and approved by regulatory agencies. The clinical outcomes of mineralized collagen are of significance to advance the evaluation and improvement of related medical device products. Some representative clinical cases have been reported, and there are more clinical applications and long-term follow-ups that currently being performed by many research groups.

  6. Effect of dietary avocado oils on hepatic collagen metabolism.

    Science.gov (United States)

    Wermam, M J; Mokady, S; Neeman, I

    1991-01-01

    The effect of various avocado and soybean oils on collagen metabolism in the liver was studied in growing female rats for 8 weeks and in day-old chicks for 1 week. In comparison with rats fed either refined avocado oil, refined or unrefined soybean oils, rats fed unrefined avocado oil showed a significant decrease in total collagen solubility in the liver, while there were no changes in total collagen, protein and moisture content. Chicks fed unrefined avocado oil as compared to those fed refined avocado oil also showed a decrease in hepatic total soluble collagen while hepatic total collagen remained unaffected. Electron micrographs and light-microscope examinations of rats' liver revealed collagen accumulation in the periportal location. This is suggestive of the early stages of fibrosis.

  7. Collagen synthesis in human musculoskeletal tissues and skin

    DEFF Research Database (Denmark)

    Babraj, J A; Cuthbertson, D J R; Smith, K

    2005-01-01

    We have developed a direct method for the measurement of human musculoskeletal collagen synthesis on the basis of the incorporation of stable isotope-labeled proline or leucine into protein and have used it to measure the rate of synthesis of collagen in tendon, ligament, muscle, and skin....... In postabsorptive, healthy young men (28 +/- 6 yr) synthetic rates for tendon, ligament, muscle, and skin collagen were 0.046 +/- 0.005, 0.040 +/- 0.006, 0.016 +/- 0.002, and 0.037 +/- 0.003%/h, respectively (means +/- SD). In postabsorptive, healthy elderly men (70 +/- 6 yr) the rate of skeletal muscle collagen...... synthesis is greater than in the young (0.023 +/- 0.002%/h, P collagen are similar to those of mixed skeletal muscle protein in the postabsorptive state, whereas the rate for muscle collagen synthesis is much lower in both young and elderly men...

  8. Collagen: a potential factor involved in the pathogenesis of glaucoma.

    Science.gov (United States)

    Huang, Wenbin; Fan, Qian; Wang, Wei; Zhou, Minwen; Laties, Alan M; Zhang, Xiulan

    2013-09-04

    Numerous studies have been completed on glaucoma pathogenesis. However, the potential and controversial interaction between ocular biomechanical properties and the glaucomatous diseases process has received much more attention recently. Previous studies have found that collagen tissues gain mutation change in glaucoma patients. This study was conducted to determine the role of collagen in the biomechanics of glaucoma in humans. Its changes may be the result of mechanical modifications brought on by intraocular pressure (IOP) fluctuations. More importantly, biomechanics and genetic evidence indicate that the mutation of collagen may play a role in the process of glaucoma. Alteration of collagen in the outflow pathway may alter mechanical tissue characteristics and a concomitant increase of aqueous humor outflow resistance and elevation of IOP. The variations of collagen, leading to inter-individual differences in scleral and lamina cribrosa properties, result in different susceptibility of individuals to elevated IOP. Therefore, this study hypothesized that collagen mutations may be an original cause of glaucoma.

  9. Regulation of collagen biosynthesis by ascorbic acid: a review.

    OpenAIRE

    Pinnell, S R

    1985-01-01

    L-ascorbic acid is an essential cofactor for lysyl hydroxylase and prolyl hydroxylase, enzymes essential for collagen biosynthesis. In addition, L-ascorbic acid preferentially stimulates collagen synthesis in a manner which appears unrelated to the effect of L-ascorbic acid on hydroxylation reactions. This reaction is stereospecific and unrelated to intracellular degradation of collagen. The effect apparently occurs at a transcriptional or translational level, since L-ascorbic acid preferenti...

  10. Enhancing collagen stability through nanostructures containing chromium(III) oxide.

    Science.gov (United States)

    Sangeetha, Selvam; Ramamoorthy, Usha; Sreeram, Kalarical Janardhanan; Nair, Balachandran Unni

    2012-12-01

    Stabilization of collagen for various applications employs chemicals such as aldehydes, metal ions, polyphenols, etc. Stability against enzymatic, thermal and mechanical degradation is required for a range of biomedical applications. The premise of this research is to explore the use of nanoparticles with suitable functionalization/encapsulation to crosslink with collagen, such that the three dimensional architecture had the desired stability. Collagen solution prepared as per standard protocols is treated with chromium(III) oxide nanoparticules encapsulated within a polymeric matrix (polystyrene-block-polyacrylic acid copolymer). Selectivity towards encapsulation was ensured by the reaction in dimethyl sulfoxide, where the PS groups popped out and encapsulated the Cr(2)O(3). Subsequently when immersed in aqueous solution, PAA units popped up to react with functional groups of collagen. The interaction with collagen was monitored through techniques such as CD, FTIR, viscosity measurements, stress analysis. CD studies and FTIR showed no degradation of collagen. Thermal stability was enhanced upon interaction of nanostructures with collagen. Self-assembly of collagen was delayed but not inhibited, indicating a compete binding of the metal oxide encapsulated polymer to collagen. Metal oxide nanoparticles encapsulated within a polymeric matrix could provide thermal and mechanical stability to collagen. The formed fibrils of collagen could serve as ideal material for various smart applications such as slow/sustained drug release. The study is also relevant to the leather industry in that the nanostructures can diffuse through the highly networked collagen fibre bundles in skin matrix easily, thus overcoming the rate limiting step of diffusion. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Crosslinking of collagen scaffolds promotes blood and lymphatic vascular stability

    OpenAIRE

    Chan, Kelvin L.S.; Khankhel, Aimal H.; Thompson, Rebecca L.; Coisman, Brent J.; Wong, Keith H.K.; Truslow, James G.; Tien, Joe

    2013-01-01

    The low stiffness of reconstituted collagen hydrogels has limited their use as scaffolds for engineering implantable tissues. Although chemical crosslinking has been used to stiffen collagen and protect it against enzymatic degradation in vivo, it remains unclear how crosslinking alters the vascularization of collagen hydrogels. In this study, we examine how the crosslinking agents genipin and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) alter vascular stability and function in microf...

  12. Macromolecular organization of chicken type X collagen in vitro

    OpenAIRE

    1991-01-01

    The macromolecular structure of type X collagen in the matrices of primary cultures of chick hypertrophic chondrocytes was initially investigated using immunoelectron microscopy. Type X collagen was observed to assemble into a matlike structure with-in the matrix elaborated by hypertrophic chondrocytes. The process of self assembly was investigated at the molecular level using purified chick type X collagen and rotary-shadowing EM. It was shown that under neutral conditions at 34 degrees C, i...

  13. Vision Restoration with a Collagen Crosslinked Boston Keratoprosthesis Unit

    Science.gov (United States)

    2016-09-01

    AWARD NUMBER: W81XWH-15-2-0044 TITLE: Vision Restoration with a Collagen Crosslinked Boston Keratoprosthesis Unit PRINCIPAL INVESTIGATOR: Joseph B...TITLE AND SUBTITLE 5a. CONTRACT NUMBER Vision Restoration with a Collagen Cross-linked Boston Keratoprosthesis Unit 5b. GRANT NUMBER W81XWH-15-2-0044...the incidence or potentially eliminate corneal melts by strengthening the keratoprosthesis carrier tissue by collagen -crosslinking the cornea graft

  14. Electrospun Collagen/Silk Tissue Engineering Scaffolds: Fiber Fabrication, Post-Treatment Optimization, and Application in Neural Differentiation of Stem Cells

    Science.gov (United States)

    Zhu, Bofan

    Biocompatible scaffolds mimicking the locally aligned fibrous structure of native extracellular matrix (ECM) are in high demand in tissue engineering. In this thesis research, unidirectionally aligned fibers were generated via a home-built electrospinning system. Collagen type I, as a major ECM component, was chosen in this study due to its support of cell proliferation and promotion of neuroectodermal commitment in stem cell differentiation. Synthetic dragline silk proteins, as biopolymers with remarkable tensile strength and superior elasticity, were also used as a model material. Good alignment, controllable fiber size and morphology, as well as a desirable deposition density of fibers were achieved via the optimization of solution and electrospinning parameters. The incorporation of silk proteins into collagen was found to significantly enhance mechanical properties and stability of electrospun fibers. Glutaraldehyde (GA) vapor post-treatment was demonstrated as a simple and effective way to tune the properties of collagen/silk fibers without changing their chemical composition. With 6-12 hours GA treatment, electrospun collagen/silk fibers were not only biocompatible, but could also effectively induce the polarization and neural commitment of stem cells, which were optimized on collagen rich fibers due to the unique combination of biochemical and biophysical cues imposed to cells. Taken together, electrospun collagen rich composite fibers are mechanically strong, stable and provide excellent cell adhesion. The unidirectionally aligned fibers can accelerate neural differentiation of stem cells, representing a promising therapy for neural tissue degenerative diseases and nerve injuries.

  15. Release of antibiotics from collagen dressing.

    Science.gov (United States)

    Grzybowski, J; Antos-Bielska, M; Ołdak, E; Trafny, E A

    1997-01-01

    Our new collagen dressing has been developed recently. Three types (A, B, and C) of the dressing were prepared in this study. Each type contained bacitracin, neomycin or colistin. The antibiotic was input into: i. collagen sponge (CS)--type A, ii. layer of limited hydrophobicity (LLH)--type B, and iii. into both CS and LLH layers--type C. The final concentration of the antibiotic that resulted from the loading level was 2 mg/cm2 for the dressings of type A and B and 4 mg/cm2 for the dressing of type C. The antibiotics were then extracted from the pieces of dressings for two days through dialysis membrane. Susceptibility of 54 bacterial strains (S. aureus, P. aeruginosa, and Acinetobacter) isolated from burn wounds were tested to the three antibiotics used for preparation of the dressings. The results of the study evidenced that efficiency of released of antibiotics into the extracts depended on the kind of antibiotic and on the type of dressing. The concentration of the antibiotics proved to be much higher than MIC90 values of the bacterial isolates tested in respect to their susceptibility. The dressing containing mixture of the three antibiotics in two layers--CS and LLH is now considered as potentially effective for care of infected wounds. It may be useful for the treatment of infected wounds or for profilaxis of contaminated wounds, ensuring: i. sufficient antimicrobial activity in wound, and ii. optimal wound environment for the presence of collagenic biomaterial on the damaged tissue.

  16. Effects of the Nd:YAG laser on DNA synthesis and collagen production in human skin fibroblast cultures

    Energy Technology Data Exchange (ETDEWEB)

    Castro, D.J.; Abergel, R.P.; Meeker, C.; Dwyer, R.M.; Lesavoy, M.A.; Uitto, J.

    1983-09-01

    Human skin fibroblasts were subjected to treatment with a Neodymium:YAG laser at 1060 nm with varying levels of energy determined by a reproducible method of dosimetry. DNA synthesis in the cells was measured by the incorporation of (3H)thymidine, and collagen production was monitored by the synthesis of nondialyzable (3H)hydroxyproline after incubation of cells with (3H)proline. Using energy levels equal to 1.7 X 10(3) J/cm2, a significant reduction in DNA synthesis was noted, while the cells remained viable as tested by the trypan blue exclusion test. With energy levels higher or equal to 2.3 X 10(3) J/cm2, the suppression of DNA synthesis was accompanied by cell nonviability. The collagen production, when measured immediately following the treatment with 1.7 X 10(3) J/cm2, was markedly reduced, and similar effects were observed with higher energy levels. However, when the cells were tested for collagen production at 20 hours following laser treatment, there was a significant decrease in collagen production at energy levels as low as 1.1 X 10(3) J/cm2, a dose that did not affect DNA synthesis or cell viability. Thus, the results indicate that the Nd:YAG laser can selectively suppress collagen production without affecting cell proliferation. These observations suggest that laser treatment could potentially be used to reduce collagen deposition in conditions such as keloids and hypertrophic scars.

  17. 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.

  18. Fibrillar Collagen Organization Associated with Broiler Wooden Breast Fibrotic Myopathy.

    Science.gov (United States)

    Velleman, Sandra G; Clark, Daniel L; Tonniges, Jeffrey R

    2017-12-01

    Wooden breast (WB) is a fibrotic myopathy affecting the pectoralis major (p. major) muscle in fast-growing commercial broiler lines. Birds with WB are phenotypically detected by the palpation of a hard p. major muscle. A primary feature of WB is the fibrosis of muscle with the replacement of muscle fibers with extracellular matrix proteins, such as collagen. The ability of a tissue to be pliable and stretch is associated with the organization of collagen fibrils in the connective tissue areas surrounding muscle fiber bundles (perimysium) and around individual muscle fibers (endomysium). The objective of this study was to compare the structure and organization of fibrillar collagen by using transmission electron microscopy in two fast-growing broiler lines (Lines A and B) with incidence of WB to a slower growing broiler Line C with no phenotypically detectable WB. In Line A, the collagen fibrils were tightly packed in a parallel organization, whereas in Line B, the collagen fibrils were randomly aligned. Tightly packed collagen fibrils arranged in parallel are associated with nonpliable collagen that is highly cross-linked. This will lead to a phenotypically hard p. major muscle. In Line C, the fibrillar collagen was sparse in its distribution. Furthermore, the average collagen fibril diameter and banding D-period length were altered in Line A p. major muscles affected with WB. Taken together, these data are suggestive of different fibrotic myopathies beyond just what is classified as WB in fast-growing broiler lines.

  19. Photo-active collagen systems with controlled triple helix architecture

    Science.gov (United States)

    Tronci, Giuseppe; Russell, Stephen J.; Wood, David J.

    2016-01-01

    The design of photo-active collagen systems is presented as a basis for establishing biomimetic materials with varied network architecture and programmable macroscopic properties. Following in-house isolation of type I collagen, reaction with vinyl-bearing compounds of varied backbone rigidity, i.e. 4-vinylbenzyl chloride (4VBC) and glycidyl methacrylate (GMA), was carried out. TNBS colorimetric assay, 1H-NMR and ATR-FTIR confirmed covalent and tunable functionalization of collagen lysines. Depending on the type and extent of functionalization, controlled stability and thermal denaturation of triple helices were observed via circular dichroism (CD), whereby the hydrogen-bonding capability of introduced moieties was shown to play a major role. Full gel formation was observed following photo-activation of functionalized collagen solutions. The presence of a covalent network only slightly affected collagen triple helix conformation (as observed by WAXS and ATR-FTIR), confirming the structural organization of functionalized collagen precursors. Photo-activated hydrogels demonstrated an increased denaturation temperature (DSC) with respect to native collagen, suggesting that the formation of the covalent network successfully stabilized collagen triple helices. Moreover, biocompatibility and mechanical competence of obtained hydrogels were successfully demonstrated under physiologically-relevant conditions. These results demonstrate that this novel synthetic approach enabled the formation of biocompatible collagen systems with defined network architecture and programmable macroscopic properties, which can only partially be obtained with current synthetic methods. PMID:27398214

  20. Utilization of Chicken By-Products to Form Collagen Films

    Directory of Open Access Journals (Sweden)

    Kumudini A. Munasinghe

    2015-01-01

    Full Text Available Chicken collagen casings could be an alternate source of collagen casings that are manufactured for sausages. The overall objective of this project was to extract chicken collagen from by-products of the broiler processing industries and to explore the possibility of making films. Chicken skin was washed, ground, and pretreated to remove the noncollagenous compounds. Collagen was extracted using acetic acid and pepsin. Solubilized collagen was salted-out and centrifuged at 20,000 ×g at 4°C for one hour. The precipitates were dissolved in 0.5 M acetic acid and dialyzed against 0.1 M acetic acid and distilled water before freeze-drying. Molecular weight, collagen solubility at different pH values, and NaCl concentrations were determined. TA-XT2 texture analyzer was used to characterize mechanical properties of collagen films. The highest collagen solubility was obtained at pH 2 and 2% NaCl. Hand-homogenized, nonfiltered, and conditioned samples had the highest hardness (3,262 g and the least brittleness (30.5 mm. These results demonstrate that chicken collagen extracted from chicken by-products has the ability to form films and could be considered for making casings or be used in various other industries.

  1. 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....

  2. Tendon collagen synthesis declines with immobilization in elderly humans

    DEFF Research Database (Denmark)

    Dideriksen, Kasper; Boesen, Anders P; Reitelseder, Søren

    2017-01-01

    -80 yr) were randomly assigned to NSAIDs (ibuprofen 1,200 mg/day; Ibu) or placebo (Plc). One lower limb was immobilized in a cast for 2 wk and retrained for 6 wk. Tendon collagen protein synthesis, mechanical properties, size, expression of genes related to collagen turnover and remodeling, and signal...... intensity (from magnetic resonance imaging) were investigated. Tendon collagen synthesis decreased (P ... immobilization in both groups, whereas scleraxis mRNA decreased with inactivity in the Plc group only (P collagen protein synthesis decreased after 2 wk of immobilization, whereas tendon stiffness and modulus were only marginally reduced, and NSAIDs had no influence upon this...

  3. 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...

  4. Stabilization and anomalous hydration of collagen fibril under heating.

    Directory of Open Access Journals (Sweden)

    Sasun G Gevorkian

    Full Text Available BACKGROUND: Type I collagen is the most common protein among higher vertebrates. It forms the basis of fibrous connective tissues (tendon, chord, skin, bones and ensures mechanical stability and strength of these tissues. It is known, however, that separate triple-helical collagen macromolecules are unstable at physiological temperatures. We want to understand the mechanism of collagen stability at the intermolecular level. To this end, we study the collagen fibril, an intermediate level in the collagen hierarchy between triple-helical macromolecule and tendon. METHODOLOGY/PRINCIPAL FINDING: When heating a native fibril sample, its Young's modulus decreases in temperature range 20-58°C due to partial denaturation of triple-helices, but it is approximately constant at 58-75°C, because of stabilization by inter-molecular interactions. The stabilization temperature range 58-75°C has two further important features: here the fibril absorbs water under heating and the internal friction displays a peak. We relate these experimental findings to restructuring of collagen triple-helices in fibril. A theoretical description of the experimental results is provided via a generalization of the standard Zimm-Bragg model for the helix-coil transition. It takes into account intermolecular interactions of collagen triple-helices in fibril and describes water adsorption via the Langmuir mechanism. CONCLUSION/SIGNIFICANCE: We uncovered an inter-molecular mechanism that stabilizes the fibril made of unstable collagen macromolecules. This mechanism can be relevant for explaining stability of collagen.

  5. Collagen metabolism in obesity: the effect of weight loss

    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...... restriction (P weight loss (r = 0.32; P obesity and associated with body fat distribution, suggesting...... an increased turnover of type III collagen related to obesity in general and to abdominal obesity in particular. S-PIIINP levels decreases during weight loss in obese subjects, whereas S-PICP levels seems un-related to obesity and weight loss....

  6. ELECTRICAL AND THERMODYNAMIC PROPERTIES OF A COLLAGEN SOLUTION

    Directory of Open Access Journals (Sweden)

    Jaromír Štancl

    2017-06-01

    Full Text Available This paper focuses on measurements of the electrical properties, the specific heat capacity and the thermal conductivity of a collagen solution (7.19% mass fraction of native bovine collagen in water. The results of our experiments show that specific electrical conductivity of collagen solution is strongly dependent on temperature. The transition region of collagen to gelatin has been observed from the measured temperature dependence of specific electrical conductivity, and has been confirmed by specific heat capacity measurements by a differential scanning calorimetry.

  7. Discoidin Domain Receptor 1 Mediates Myosin-Dependent Collagen Contraction

    Directory of Open Access Journals (Sweden)

    Nuno M. Coelho

    2017-02-01

    Full Text Available Discoidin domain receptor 1 (DDR1 is a tyrosine kinase collagen adhesion receptor that mediates cell migration through association with non-muscle myosin IIA (NMIIA. Because DDR1 is implicated in cancer fibrosis, we hypothesized that DDR1 interacts with NMIIA to enable collagen compaction by traction forces. Mechanical splinting of rat dermal wounds increased DDR1 expression and collagen alignment. In periodontal ligament of DDR1 knockout mice, collagen mechanical reorganization was reduced >30%. Similarly, cultured cells with DDR1 knockdown or expressing kinase-deficient DDR1d showed 50% reduction of aligned collagen. Tractional remodeling of collagen was dependent on DDR1 clustering, activation, and interaction of the DDR1 C-terminal kinase domain with NMIIA filaments. Collagen remodeling by traction forces, DDR1 tyrosine phosphorylation, and myosin light chain phosphorylation were increased on stiff versus soft substrates. Thus, DDR1 clustering, activation, and interaction with NMIIA filaments enhance the collagen tractional remodeling that is important for collagen compaction in fibrosis.

  8. Small-bowel permeability in collagenous colitis

    DEFF Research Database (Denmark)

    Wildt, Signe; Madsen, Jan L; Rumessen, Jüri J

    2006-01-01

    Collagenous colitis (CC) is a chronic inflammatory bowel disease that affects the colon. However, some patients with CC present with accompanying pathologic small-bowel manifestations such as coeliac disease, defects in bile acid absorption and histopathologic changes in small-intestinal biopsies......, indicating that CC is a pan-intestinal disease. In small-intestinal disease, the intestinal barrier function may be impaired, and the permeability of the small intestine altered. The purpose of this research was to study small-bowel function in patients with CC as expressed by intestinal permeability....

  9. Injured fingertip remodeling through percutaneous collagen induction

    Directory of Open Access Journals (Sweden)

    N. Krezdorn

    2016-07-01

    Full Text Available Scarring at the level of the fingertip can cause major problems and discomfort. We report a case of a professional bass player who suffered impaired functionality of his middle finger after surgical treatment of a felon. We performed a collagen induction therapy after plastic reconstruction of the middle finger’s fingertip with an adipofascial turnover flap and two lateral VY flaps. This resulted in a long-term improvement of the previous symptoms and full functional rehabilitation as musician with an esthetically pleasing result.

  10. A modified collagen gel dressing promotes angiogenesis in a preclinical swine model of chronic ischemic wounds.

    Science.gov (United States)

    Elgharably, Haytham; Ganesh, Kasturi; Dickerson, Jennifer; Khanna, Savita; Abas, Motaz; Ghatak, Piya Das; Dixit, Sriteja; Bergdall, Valerie; Roy, Sashwati; Sen, Chandan K

    2014-01-01

    We recently performed proteomic characterization of a modified collagen gel (MCG) dressing and reported promising effects of the gel in healing full-thickness excisional wounds. In this work, we test the translational relevance of our aforesaid findings by testing the dressing in a swine model of chronic ischemic wounds recently reported by our laboratory. Full-thickness excisional wounds were established in the center of bipedicle ischemic skin flaps on the backs of animals. Ischemia was verified by laser Doppler imaging, and MCG was applied to the test group of wounds. Seven days post wounding, macrophage recruitment to the wound was significantly higher in MCG-treated ischemic wounds. In vitro, MCG up-regulated expression of Mrc-1 (a reparative M2 macrophage marker) and induced the expression of anti-inflammatory cytokine interleukin (IL)-10 and of fibroblast growth factor-basic (β-FGF). An increased expression of CCR2, an M2 macrophage marker, was noted in the macrophages from MCG treated wounds. Furthermore, analyses of wound tissues 7 days post wounding showed up-regulation of transforming growth factor-β, vascular endothelial growth factor, von Willebrand's factor, and collagen type I expression in MCG-treated ischemic wounds. At 21 days post wounding, MCG-treated ischemic wounds displayed higher abundance of proliferating endothelial cells that formed mature vascular structures and increased blood flow to the wound. Fibroblast count was markedly higher in MCG-treated ischemic wound-edge tissue. In addition, MCG-treated wound-edge tissues displayed higher abundance of mature collagen with increased collagen type I : III deposition. Taken together, MCG helped mount a more robust inflammatory response that resolved in a timely manner, followed by an enhanced proliferative phase, angiogenic outcome, and postwound tissue remodeling. Findings of the current study warrant clinical testing of MCG in a setting of ischemic chronic wounds. © 2014 by the Wound

  11. Stiff collagen matrices increase tumorigenic prolactin signaling in breast cancer cells.

    Science.gov (United States)

    Barcus, Craig E; Keely, Patricia J; Eliceiri, Kevin W; Schuler, Linda A

    2013-05-03

    Clinically, circulating prolactin levels and density of the extracellular matrix (ECM) are individual risk factors for breast cancer. As tumors develop, the surrounding stroma responds with increased deposition and cross-linking of the collagen matrix (desmoplasia). In mouse models, prolactin promotes mammary carcinomas that resemble luminal breast cancers in women, and increased collagen density promotes tumor metastasis and progression. Although the contributions of the ECM to the physiologic actions of prolactin are increasingly understood, little is known about the functional relationship between the ECM and prolactin signaling in breast cancer. Here, we examined consequences of increased ECM stiffness on prolactin signals to luminal breast cancer cells in three-dimensional collagen I matrices in vitro. We showed that matrix stiffness potently regulates a switch in prolactin signals from physiologic to protumorigenic outcomes. Compliant matrices promoted physiological prolactin actions and activation of STAT5, whereas stiff matrices promoted protumorigenic outcomes, including increased matrix metalloproteinase-dependent invasion and collagen scaffold realignment. In stiff matrices, prolactin increased SRC family kinase-dependent phosphorylation of focal adhesion kinase (FAK) at tyrosine 925, FAK association with the mitogen-activated protein kinase mediator GRB2, and pERK1/2. Stiff matrices also increased co-localization of prolactin receptors and integrin-activated FAK, implicating altered spatial relationships. Together, these results demonstrate that ECM stiffness is a powerful regulator of the spectrum of prolactin signals and that stiff matrices and prolactin interact in a feed-forward loop in breast cancer progression. Our study is the first reported evidence of altered ECM-prolactin interactions in breast cancer, suggesting the potential for new therapeutic approaches.

  12. Effects of fish collagen peptides on collagen post-translational modifications and mineralization in an osteoblastic cell culture system

    OpenAIRE

    Yamada, Shizuka; Nagaoka, Hideaki; Terajima, Masahiko; Tsuda, Nobuaki; Hayashi, Yoshihiko; Yamauchi, Mitsuo

    2013-01-01

    Collagen is one of the most widely used biomaterials for tissue engineering and regenerative medicine. Fish collagen peptides (FCP) have been used as a dietary supplement, but their effects on the cellular function are still poorly understood. The objective of this study was to investigate the effects of FCP on collagen synthesis, quality and mineralization using an osteoblastic MC3T3-E1 cell culture system. Cells treated with FCP significantly upregulated the gene expression of several colla...

  13. Cthrc1 lowers pulmonary collagen associated with bleomycin-induced fibrosis and protects lung function.

    Science.gov (United States)

    Binks, Andrew P; Beyer, Megyn; Miller, Ryan; LeClair, Renee J

    2017-03-01

    Idiopathic pulmonary fibrosis (IPF) involves collagen deposition that results in a progressive decline in lung function. This process involves activation of Smad2/3 by transforming growth factor (TGF)- β and Wnt signaling pathways. Collagen Triple Helix Repeat-Containing-1 (Cthrc1) protein inhibits Smad2/3 activation. To test the hypothesis that Cthrc1 limits collagen deposition and the decline of lung function, Cthrc1 knockout (Cthrc1 -/- ) and wild-type mice (WT) received intratracheal injections of 2.5 U/kg bleomycin or saline. Lungs were harvested after 14 days and Bronchoalveolar lavage (BAL) TGF- β , IL1- β , hydroxyproline and lung compliance were assessed. TGF- β was significantly higher in Cthrc1 -/- compared to WT (53.45 ± 6.15 ng/mL vs. 34.48 ± 11.05) after saline injection. Bleomycin injection increased TGF- β in both Cthrc1 -/- (66.37 ± 8.54 ng/mL) and WT (63.64 ± 8.09 ng/mL). Hydroxyproline was significantly higher in Cthrc1 -/- compared to WT after bleomycin-injection (2.676 ± 0.527  μ g/mg vs. 1.889 ± 0.520, P  = 0.028). Immunohistochemistry of Cthrc1 -/- lung sections showed intracellular localization and activation of β -catenin Y654 in areas of tissue remodeling that was not evident in WT Lung compliance was significantly reduced by bleomycin in Cthrc1 -/- but there was no effect in WT animals. These data suggest Cthrc1 reduces fibrotic tissue formation in bleomycin-induced lung fibrosis and the effect is potent enough to limit the decline in lung function. We conclude that Cthrc1 plays a protective role, limiting collagen deposition and could form the basis of a novel therapy for pulmonary fibrosis. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  14. Optimal bovine collagen concentration to achieve tracheal epithelial coverage of collagen sponges.

    Science.gov (United States)

    Suzuki, Ryo; Nakamura, Ryosuke; Nakaegawa, Yuta; Nomoto, Yukio; Fujimoto, Ichiro; Semura, Kayoko; Hazama, Akihiro; Omori, Koichi

    2016-12-01

    Artificial tracheas prepared using a collagen sponge and polypropylene mesh have been implanted in patients who received tracheal resections, but epithelialization in the reconstructed area is slow. We determined the optimal bovine atelocollagen concentration necessary for the rapid and complete tracheal epithelial coverage of collagen sponge implants. Preliminary animal experiment. Collagen sponges were prepared using lyophilizing 0.5%, 0.7%, and 1.0% atelocollagen solutions (0.5%, 0.7%, and 1.0% sponges) and were analyzed using scanning electron microscopy. Partial tracheal defects were prepared in rabbits and reconstructed using sponges. Epithelial regeneration in the reconstructed area was evaluated by endoscopic, histological, and scanning electron microscope analyses. All sponges had a membranous structural framework, and numerous fibrous structures filled the spaces within the framework in the 0.5% sponges. The membranous structure in the 0.7% sponges branched at many points, and intermembrane spaces were frequently observed. Conversely, the membranous structure in the 1.0% sponges was relatively continuous, thick, and closely arranged. Two weeks after implantation, tracheal defects were entirely covered with epithelium in two of the four and three of the four of the 0.5% and 0.7% sponge-implanted rabbits, respectively. The collagen sponges remained exposed to the tracheal lumen in four of the four rabbits in the 1.0% sponge group. Ciliogenesis in the center of the epithelialized region was detected only in the 0.7% sponge group. Collagen sponges prepared from various concentrations of bovine atelocollagen have different structures. Complete epithelial coverage was achieved in more rabbits implanted with sponges prepared using the 0.7% bovine atelocollagen solution than in those implanted with sponges prepared from the 0.5% and 1.0% solutions. NA Laryngoscope, 126:E396-E403, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  15. Microstructural and Mechanical Differences Between Digested Collagen-Fibrin Co-Gels and Pure Collagen and Fibrin Gels

    Science.gov (United States)

    Lai, Victor K.; Frey, Christina R.; Kerandi, Allan M.; Lake, Spencer P.; Tranquillo, Robert T.; Barocas, Victor H.

    2012-01-01

    Collagen and fibrin are important extra-cellular matrix (ECM) components in the body, providing structural integrity to various tissues. These biopolymers are also common scaffolds used in tissue engineering. This study investigated how co-gelation of collagen and fibrin affected the properties of each individual protein network. Collagen-fibrin co-gels were cast and subsequently digested using either plasmin or collagenase; the microstructure and mechanical behavior of the resulting networks were then compared with respective pure collagen or fibrin gels of the same protein concentration. The morphologies of the collagen networks were further analyzed via 3-D network reconstruction from confocal image z-stacks. Both collagen and fibrin exhibited a decrease in mean fiber diameter when formed in the co-gels compared to the pure gels; this microstructural change was accompanied by increased failure strain and decreased tangent modulus for both collagen and fibrin following selected digestion of the co-gels. In addition, analysis of the reconstructed collagen networks indicated presence of very long fibers and clustering of fibrils, resulting in very high connectivities for collagen networks formed in co-gels. PMID:22828381

  16. Platelet affinity for burro aorta collagen

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M.D.

    1977-10-01

    Despite ingenious concepts, there are no unequivocal clues as to what, when, and how some undefined biochemical factor(s) or constituent(s) that localizes in the arterial wall can precipitate a thromboatheromatous lesion or arterial disease. The present study focused on the extraction, partial purification, and characterization of a collagen-active platelet stimulator from the aortas of aged burros. The aggregator moiety in the aorta extracts invariably had a higher affinity for platelets in citrated platelet-rich plasma of human beings than for platelets of homologous burros. The platelet-aggregating factor(s) in the aorta extract was retained by incubation with ..cap alpha..-chymotrypsin. Platelet-aggregating activity was rapidly abolished after incubation with collagenase, as determined by platelet-aggregometry tests. Evidence based on light microscope and polysaccharide histochemical reactions indicates a probability that the intracellular amorphous matrix (PAS-positive) and filamentous components (PTAH-positive) expelled from smooth muscle cells disrupted during homogenization of the aorta may be a principal source of a precursor collagen species which is a potent inducer of platelet aggregation.

  17. Optimal management of collagenous colitis: a review

    Directory of Open Access Journals (Sweden)

    O’Toole A

    2016-02-01

    Full Text Available Aoibhlinn O’TooleDepartment of Gastroenterology, Beaumont Hospital, Dublin, Ireland Abstract: Collagenous colitis (CC is an increasingly recognized cause of chronic inflammatory bowel disease characterized by watery non-bloody diarrhea. As a lesser studied inflammatory bowel disease, many aspects of the CC's natural history are poorly understood. This review discusses strategies to optimally manage CC. The goal of therapy is to induce clinical remission, <3 stools a day or <1 watery stool a day with subsequent improved quality of life (QOL. Antidiarrheal can be used as monotherapy or with other medications to control diarrhea. Budesonide therapy has revolutionized treatment and is superior to prednisone, however, the treatment is associated with high-relapse rates and the management of refractory disease is challenging. Ongoing trials will address the safety and efficacy of low-dose maintenance therapy. For those with refractory disease, case reports and case series support the role of biologic agents. Diversion of the fecal stream normalizes colonic mucosal changes and ileostomy may be considered where anti-tumor necrosis factor (TNF-α agents are contraindicated. Underlying celiac disease, bile salt diarrhea, and associated thyroid dysfunction should be ruled out. The author recommends smoking cessation as well as avoidance of nonsteroidal anti-inflammatories as well as other associated medications. Keywords: microscopic, collagenous, lymphocytic, colitis, diarrhea, budesonide, inflammatory bowel disease

  18. Structure and formation of the twisted plywood pattern of collagen fibrils in rat lamellar bone.

    Science.gov (United States)

    Yamamoto, Tsuneyuki; Hasegawa, Tomoka; Sasaki, Muneteru; Hongo, Hiromi; Tabata, Chihiro; Liu, Zhusheng; Li, Minqi; Amizuka, Norio

    2012-04-01

    This study was designed to elucidate details of the structure and formation process of the alternate lamellar pattern known to exist in lamellar bone. For this purpose, we examined basic internal lamellae in femurs of young rats by transmission and scanning electron microscopy, the latter employing two different macerations with NaOH at concentrations of 10 and 24%. Observations after the maceration with 10% NaOH showed that the regular and periodic rotation of collagen fibrils caused an alternation between two types of lamellae: one consisting of transversely and nearly transversely cut fibrils, and the other consisting of longitudinally and nearly longitudinally cut fibrils. This finding confirms the consistency of the twisted plywood model. The maceration method with 24% NaOH removed bone components other than cells, thus allowing for three-dimensional observations of osteoblast morphology. Osteoblasts extended finger-like processes paralleling the inner bone surface, and grouped in such a way that, within a group, the processes arranged in a similar direction. Transmission electron microscopy showed that newly deposited fibrils were arranged alongside these processes. For the formation of the alternating pattern, our findings suggest that: (1) osteoblasts control the collagen fibril arrangement through their finger-like process position; (2) osteoblasts behave similarly within a group; (3) osteoblasts move their processes synchronously and periodically to promote alternating different fibril orientation; and (4) this dynamic sequential deposition of fibrils results in the alternate lamellar (or twisted plywood) pattern.

  19. Silicone Substrate with Collagen and Carbon Nanotubes Exposed to Pulsed Current for MSC Osteodifferentiation

    Directory of Open Access Journals (Sweden)

    Daniyal Jamal

    2017-01-01

    Full Text Available Autologous human adipose tissue-derived mesenchymal stem cells (MSCs have the potential for clinical translation through their induction into osteoblasts for regeneration. Bone healing can be driven by biophysical stimulation using electricity for activating quiescent adult stem cells. It is hypothesized that application of electric current will enhance their osteogenic differentiation, and addition of conductive carbon nanotubes (CNTs to the cell substrate will provide increased efficiency in current transmission. Cultured MSCs were seeded and grown onto fabricated silicone-based composites containing collagen and CNT fibers. Chemical inducers, namely, glycerol phosphate, dexamethasone, and vitamin C, were then added to the medium, and pulsatile submilliampere electrical currents (about half mA for 5 cycles at 4 mHz, twice a week were applied for two weeks. Calcium deposition indicative of MSC differentiation and osteoblastic activity was quantified through Alizarin Red S and spectroscopy. It was found that pulsed current significantly increased osteodifferentiation on silicone-collagen films without CNTs. Under no external current, the presence of 10% (m/m CNTs led to a significant and almost triple upregulation of calcium deposition. Both CNTs and current parameters did not appear to be synergistic. These conditions of enhanced osteoblastic activities may further be explored ultimately towards future therapeutic use of MSCs.

  20. 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...

  1. Preparation and characterization of porous crosslinked collagenous matrices containing bioavailable chondroitin sulphate

    NARCIS (Netherlands)

    Pieper, J.S.; Oosterhof, A.; Dijkstra, Pieter J.; Veerkamp, J.H.; van Kuppevelt, T.H.

    1999-01-01

    Porous collagen matrices with defined physical, chemical and biological characteristics are interesting materials for tissue engineering. Attachment of glycosaminoglycans (GAGs) may add to these characteristics and valorize collagen. In this study, porous type I collagen matrices were crosslinked

  2. Collagen-curcumin interaction-A physico-chemical study

    Indian Academy of Sciences (India)

    The results suggest that significant changes in viscosity and surface tension occur on collagen interacting with curcumin. Secondary structure analysis using circular dichroism shows that curcumin does not alter the triple helical structure of collagen. Increasing concentration of curcumin resulted in aggregation of the protein.

  3. Fish collagen is an important panallergen in the Japanese population.

    Science.gov (United States)

    Kobayashi, Y; Akiyama, H; Huge, J; Kubota, H; Chikazawa, S; Satoh, T; Miyake, T; Uhara, H; Okuyama, R; Nakagawara, R; Aihara, M; Hamada-Sato, N

    2016-05-01

    Collagen was identified as a fish allergen in early 2000s. Although its allergenic potential has been suggested to be low, risks associated with collagen as a fish allergen have not been evaluated to a greater extent. In this study, we aimed to clarify the importance of collagen as a fish allergen. Our results showed that 50% of Japanese patients with fish allergy had immunoglobulin E (IgE) against mackerel collagen, whereas 44% had IgE against mackerel parvalbumin. IgE inhibition assay revealed high cross-reactivity of mackerel collagen to 22 fish species (inhibition rates: 87-98%). Furthermore, a recently developed allergy test demonstrated that collagen triggered IgE cross-linking on mast cells. These data indicate that fish collagen is an important and very common panallergen in fish consumed in Japan. The high rate of individuals' collagen allergy may be attributable to the traditional Japanese custom of raw fish consumption. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Pyridinium cross-links in heritable disorders of collagen

    Energy Technology Data Exchange (ETDEWEB)

    Pasquali, M.; Still, M.J.; Dembure, P.P. [Emory Univ., Atlanta, GA (United States)] [and others

    1995-12-01

    Ehlers-Danlos syndrome (EDS) is a heterogeneous group of inherited disorders of collagen that is characterized by skin fragility, skin hyperextensibility, and joint hypermobility. EDS type VI is caused by impaired collagen lysyl hydroxylase (procollagen-lysine, 2-oxoglutarate 5-dioxygenase; E.C.1.14.11.4), the ascorbate-dependent enzyme that hydroxylates lysyl residues on collagen neopeptides. Different alterations in the gene for collagen lysyl hydroxylase have been reported in families with EDS type VI. In EDS type VI, impairment of collagen lysyl hydroxylase results in a low hydroxylysine content in mature collagen. Hydroxylysine is a precursor of the stable, covalent, intermolecular cross-links of collagen, pyridinoline (Pyr), and deoxypyridinoline (Dpyr). Elsewhere we reported in preliminary form that patients with EDS type VI had a distinctive alteration in the urinary excretion of Pyr and Dpyr. In the present study, we confirm that the increased Dpyr/Pyr ratio is specific for EDS type VI and is not observed in other inherited or acquired collagen disorders. In addition, we find that skin from patients with EDS type VI has reduced Pyr and increased Dpyr, which could account for the organ pathology. 19 refs., 1 tab.

  5. Metabolic and inflammatory faecal markers in collagenous colitis

    DEFF Research Database (Denmark)

    Wildt, Signe; Nordgaard-Lassen, Inge; Bendtsen, Flemming

    2007-01-01

    To evaluate the excretion of the inflammatory and metabolic faecal markers calprotectin, lactoferrin, and short-chain fatty acids in symptomatic and quiescent collagenous colitis.......To evaluate the excretion of the inflammatory and metabolic faecal markers calprotectin, lactoferrin, and short-chain fatty acids in symptomatic and quiescent collagenous colitis....

  6. Effect of Mechanical Stretching of the Skin on Collagen Fibril ...

    African Journals Online (AJOL)

    Stabilization of collagen fibres during development and through growth to maturation has now become fairly documented. In vitro effect of mechanical stretching of ratsf skin on oxidative deamination of ε-NH2-groups of lysine and hydroxylysine, and functional properties of its type . collagen were studied. Experiments were ...

  7. The role of collagen in determining bone mechanical properties

    NARCIS (Netherlands)

    Wang, X.; Bank, R.A.; teKoppele, J.M.; Mauli Agrawal, C.

    2001-01-01

    The hypothesis of this study was that collagen denaturation would lead to a significant decrease in the toughness of bone, but has little effect on the stiffness of bone. Using a heating model, effects of collagen denaturation on the biomechanical properties of human cadaveric bone were examined.

  8. Collagenous colitis as a possible cause of toxic megacolon.

    LENUS (Irish Health Repository)

    Fitzgerald, S C

    2009-03-01

    Collagenous colitis is a microscopic colitis characterized by normal appearing colonic mucosa on endoscopy. It is regarded as a clinically benign disease which rarely results in serious complications. We report a case of toxic megacolon occurring in a patient with collagenous colitis. This is the first reported case of toxic megacolon occurring in this subset of patients.

  9. Enhanced physicochemical properties of collagen by using EDC ...

    Indian Academy of Sciences (India)

    Introduction. The necessity of bone substitutes for wound healing has promoted development of the biomimetic bone biomateri- als. Collagen, therefore, becomes a popular biomaterial for this purpose due to its compatibility. The desired properties of collagen which facilitates wound-healing processes are stimulation of cell ...

  10. Human cornea modeling using artificial collagen

    OpenAIRE

    Bukanina, V.; Khokhlov, A.; Lovetskiy, K.

    2011-01-01

    This article focuses on spectrophotometric analysis of thin films of synthetic collagen with subsequent use of the received data to recover the optical properties of collagen and modeling a multilayer optical structure similar to the properties of human cornea.

  11. Arrangement of collagen fibers in human placental stem villi.

    Science.gov (United States)

    Sati, Leyla; Demir, Ayse Yasemin; Sarikcioglu, Levent; Demir, Ramazan

    2008-01-01

    The aim of the study was to investigate the arrangements and related localization patterns of different collagen types in the stroma of placental stem villi by immunohistochemistry and electron microscopy. A total of 14 normal human term placental tissue samples were studied. Immunohistochemistry was performed in order to localize collagen types I, III, IV, V and cytokeratin 7 on tissue sections. Parallel tissue samples were examined by transmission electron microscopy. Semi-quantitative analysis of immunolabeling intensities was also performed to determine the distribution of fibers in stem villi stroma. All collagen types, especially collagen type V, were strongly immunopositive in the triangular areas of the stem villi stroma. However, there was no collagen type I or type III immunolabeling in the sub-trophoblastic regions. Membrane collagen type IV immunolabeling was also observed in the stroma of stem villi. Ultrastructurally, collagen fibers showed different configurations in cross, longitudinal, circular, oblique and parallel directions compared to the villous axis. We conclude that the organization of collagen fiber bundles in stem villi shows a very specific arrangement: a compact coat formed by fibrillar bundles between the vascular wall and extravascular stroma of stem villi correlated with the functional activity.

  12. Distribution of different collagen types and fibronectin in neurofibromatosis tumours.

    Science.gov (United States)

    Peltonen, J; Aho, H; Halme, T; Näntö-Salonen, K; Lehto, M; Foidart, J M; Duance, V; Vaheri, A; Penttinen, R

    1984-09-01

    Collagen types I, III, IV and V and fibronectin were localized in neurofibromas from six patients with von Recklinghausen's neurofibromatosis (NF) using indirect immunofluorescence (IIF) and peroxidase anti-peroxidase (PAP) techniques. Type I and III collagens were abundantly and rather evenly present in the tumours and formed a continuous network, but were absent from the capillary endothelial walls and were sparse in the perineurium of the occasional nerve fascicles. The type III/type I + type III collagen ratio in neurofibromas varied from 17.4% to 37.3% when estimated with cyanogen bromide peptide analysis. Fibronectin was detected in areas where type I and III collagens were present but was most intensively stained in the vascular walls and perineurium. Type IV collagen was detected at the dermo-epidermal junction of the skin overlying the tumours, in the endothelial cells of the capillaries, the perineurium and endoneurium. Furthermore, in the tumourous stroma there was plenty of type IV collagen appearing as a discontinuous patchy pattern suggesting abundant basement membrane material associated with cells forming the tumours. Type V collagen distribution was very similar to that of type IV collagen.

  13. Extraction, structural and physical characterization of type I collagen ...

    African Journals Online (AJOL)

    The acid soluble collagen (ASC) and pepsin soluble collagen (PSC) were extracted from the outer skin of Sepiella inermis and further characterized partially. The yield of ASC was low (0.58% on dry weight basis); whereas the yield of PSC was comparatively more (16.23% on dry weight basis). The protein content in ASC ...

  14. Collagen a natural scaffold for biology and engineering

    Science.gov (United States)

    Collagen, the most abundant protein in mammals, constitutes a quarter of the animal's total weight. The unique structure of fibrous collagens, a long triple helix that further associates into fibers, provides an insoluble scaffold that gives strength and form to the skin, tendons, bones, cornea and...

  15. Collagen levels are normalized after decompression of experimentally obstructed colon

    DEFF Research Database (Denmark)

    Rehn, Martin; Ågren, Sven Per Magnus; Syk, I

    2011-01-01

    Our aim was to define the dynamics in collagen concentrations in the large bowel wall following decompression of experimental obstruction.......Our aim was to define the dynamics in collagen concentrations in the large bowel wall following decompression of experimental obstruction....

  16. Urinary collagen fragments are significantly altered in diabetes

    DEFF Research Database (Denmark)

    2010-01-01

    ) with 85% (95% CI: 81-88%) accuracy. Specific collagen fragments were associated with diabetes and type of diabetes indicating changes in collagen turnover and extracellular matrix as one hallmark of the molecular pathophysiology of diabetes. Additional biomarkers including inflammatory processes and pro...

  17. Regional Mechanics Determine Collagen Fiber Structure in Healing Myocardial Infarcts

    Science.gov (United States)

    Fomovsky, Gregory M.; Rouillard, Andrew D.; Holmes, Jeffrey W.

    2012-01-01

    Following myocardial infarction, the mechanical properties of the healing infarct are an important determinant of heart function and the risk of progression to heart failure. In particular, mechanical anisotropy (having different mechanical properties in different directions) in the healing infarct can preserve pump function of the heart. Based on reports of different collagen structures and mechanical properties in various animal models, we hypothesized that differences in infarct size, shape, and/or location produce different patterns of mechanical stretch that guide evolving collagen fiber structure. We tested the effects of infarct shape and location using a combined experimental and computational approach. We studied mechanics and collagen fiber structure in cryoinfarcts in 53 Sprague-Dawley rats and found that regardless of shape or orientation, cryoinfarcts near the equator of the left ventricle stretched primarily in the circumferential direction and developed circumferentially aligned collagen, while infarcts at the apex stretched similarly in the circumferential and longitudinal direction and developed randomly oriented collagen. In a computational model of infarct healing, an effect of mechanical stretch on fibroblast and collagen alignment was required to reproduce the experimental results. We conclude that mechanical environment determines collagen fiber structure in healing myocardial infarcts. Our results suggest that emerging post-infarction therapies that alter regional mechanics will also alter infarct collagen structure, offering both potential risks and novel therapeutic opportunities. PMID:22418281

  18. The collagen microfibril model, a tool for biomaterials scientists

    Science.gov (United States)

    Animal hides, a major byproduct of the meat industry, are a rich source of collagen, a structural protein of the extracellular matrix that gives strength and form to the skin, tendons and bones of mammals. The structure of fibrous collagen, a long triple helix that self-associates in a staggered arr...

  19. Enzymatic Breakdown of Type II Collagen in the Human Vitreous

    NARCIS (Netherlands)

    van Deemter, Marielle; Pas, Hendri H.; Kuijer, Roel; van der Worp, Roelofje J.; Hooymans, Johanna M. M.; Los, Leonoor I.

    2009-01-01

    PURPOSE. To investigate whether enzymatic collagen breakdown is an active process in the human vitreous. METHODS. Human donor eyes were used for immunohistochemistry to detect the possible presence of the matrix metalloproteinase (MMP)-induced type II collagen breakdown product col2-3/4C-short in

  20. Colorful protein-based fluorescent probes for collagen imaging.

    Directory of Open Access Journals (Sweden)

    Stijn J A Aper

    Full Text Available Real-time visualization of collagen is important in studies on tissue formation and remodeling in the research fields of developmental biology and tissue engineering. Our group has previously reported on a fluorescent probe for the specific imaging of collagen in live tissue in situ, consisting of the native collagen binding protein CNA35 labeled with fluorescent dye Oregon Green 488 (CNA35-OG488. The CNA35-OG488 probe has become widely used for collagen imaging. To allow for the use of CNA35-based probes in a broader range of applications, we here present a toolbox of six genetically-encoded collagen probes which are fusions of CNA35 to fluorescent proteins that span the visible spectrum: mTurquoise2, EGFP, mAmetrine, LSSmOrange, tdTomato and mCherry. While CNA35-OG488 requires a chemical conjugation step for labeling with the fluorescent dye, these protein-based probes can be easily produced in high yields by expression in E. coli and purified in one step using Ni2+-affinity chromatography. The probes all bind specifically to collagen, both in vitro and in porcine pericardial tissue. Some first applications of the probes are shown in multicolor imaging of engineered tissue and two-photon imaging of collagen in human skin. The fully-genetic encoding of the new probes makes them easily accessible to all scientists interested in collagen formation and remodeling.

  1. Effect of UV irradiation on type I collagen fibril formation in neutral collagen solutions.

    Science.gov (United States)

    Menter, J M; Patta, A M; Sayre, R M; Dowdy, J; Willis, I

    2001-06-01

    Collagens have the well-known ability to spontaneously self-associate to form fibrils at physiological temperature and neutral pH in vitro and in vivo. Because solar UV may photochemically alter collagen, the kinetics of fibril formation may be modified. Thus, we have begun a systematic study of the effect of various UV wavebands on fibril formation. Citrate-soluble calf skin collagen (Elastin Products) was dissolved at 0.05% in 0.5 M HOAc, dialyzed over 2 days into two changes of 0.0327 M phosphate buffer, pH 7.0 at 4 degrees C, and centrifuged at 48,000 x g. Photolysis was carried out at 4 degrees C with either (a) UVC (UVG-11 lamp), (b) filtered solar-simulating radiation (SSR) or UVA (SSR or UVL-21 lamp filtered with a 2.0 mm Schott WG 345 filter). Gelation was commenced by rapidly raising the temperature from 8 degrees C to 33 degrees C. Nucleation and growth were followed by turbidimetric measurements at 400 nm. UVC radiation (0-17.3 J/cm2) resulted in a dose-dependent decrease in the rate of fibril growth. Under these conditions, concomitant collagen crosslinking and degradation occurred. Fibril nucleation, a prerequisite for growth, was rapid (threshold approximately 2 min) and was not affected by UVC, UVA or SSR. SSR (0-1,320 J/cm2) caused a small decrease in growth rate and in the degree of fibril formation. UVA radiation (0-1,080 J/cm2) had a similar effect. "Direct" photochemical damage thus paralleled absorption via various collagen chromophores, with UVC>SSR approximately UVA. The presence of riboflavin (RF) resulted in groundstate interactions that markedly altered both nucleation and growth kinetics. Irradiation with 29.6 J/ cm2 UVA in the presence of RF photosensitizer caused relatively minor additional changes in fibrillation kinetics. These results collectively indicate that fibril formation is markedly dependent on specific ground state interactions and relatively insensitive to nonspecific UV damage. On the other hand, fibrils thus formed from

  2. Pathomorphological feature of chronic pancreatitis (CP is the development of pancreatic fibrosis with the accumulation of various collagen types, tubulin, fibronectin, laminin, and also intermediate filament proteins produced by activated pancreatic stel

    Directory of Open Access Journals (Sweden)

    T. V. Turovskaya

    2013-04-01

    Full Text Available T. V. Turovskaya, A. M. Gnilorybov, L. V. Vasilyeva Pathomorphological feature of chronic pancreatitis (CP is the development of pancreatic fibrosis with the accumulation of various collagen types, tubulin, fibronectin, laminin, and also intermediate filament proteins produced by activated pancreatic stellate cells (PSCs, which express the cytoskeletal α-smooth muscle actin (α-SMA. The aim of the research: determination of immunophenotype and proliferative activity of pancreatic stellate cells as well as the main histotopographic components of severe pancreatic fibrosis and accumulation of collagen I, III and IV types in pancreas at CP. Materials and methods. Histological, histochemical (Van Gieson's and Masson's trichrome staining, immunohistochemical (α-SMA, vimentin, desmin, fibronectin, Ki-67, collagen I, III and IV types and morphometric studies (Image J program of accumulation of various collagen types, represented in standard unit of optical density (SUOD, were held at pancreas biopsies of 30 patients (35-72 years old with CP. Results. It was found that development of severe pancreatic fibrosis is promoted by proliferation and increase of α-SMA+, vimentin+, desmin+ activated stellate cells and deposition of significant amount of collagen I, III, IV types and fibronectin in pancreas that are synthesized by PSCs. In areas of severe fibrosis Ki-67 expression is detected in the nuclei of at least 25% of PSCs, that corresponds to relatively low levels of proliferation. Four components of severe pancreatic fibrosis: circular-periductal fibrosis involving the large ducts of the pancreas, laminar fibrosis in extensive fibrous fields between large ducts and acinar tissue, as well as tape-like interlobular and septal-periacinar intralobular pancreatic fibrosis are identified in patients with CP. Conclusion. Morphological manifestation of severe circular-periductal pancreatic fibrosis is the presence of significant concentric fibrosis around the

  3. Collagen-derived markers of bone metabolism in osteogenesis imperfecta

    DEFF Research Database (Denmark)

    Lund, A M; Hansen, M; Kollerup, Gina Birgitte

    1998-01-01

    Markers of bone formation [C-terminal and N-terminal propeptides of procollagen I (PICP, PINP), osteocalcin and alkaline phosphatase] and bone resorption [C-terminal cross-linked telopeptide of collagen I (ICTP) and hydroxypyridinium cross-links, pyridinoline (Pyr) and deoxypyridinoline (Dpyr......)] were measured in 78 osteogenesis imperfecta (OI) patients to investigate bone metabolism in vivo and relate marker concentrations to phenotype and in vitro collagen I defects, as shown by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). PICP and PINP were generally low......, and the serum levels were lower in all children and adults with mild OI and a quantitative collagen defect than in patients with severe OI and a qualitative collagen I defect. ICTP, Pyr and Dpyr were generally normal or reduced, but elevated in severely affected adults with a qualitative collagen I defect...

  4. Photo-active collagen systems with controlled triple helix architecture

    CERN Document Server

    Tronci, Giuseppe; Wood, David J

    2013-01-01

    The design of photo-active collagen systems is presented as a basis for establishing biomimetic materials with varied network architecture and programmable macroscopic properties. Following in-house isolation of type I collagen, reaction with vinyl-bearing compounds of varied backbone rigidity, i.e. 4-vinylbenzyl chloride (4VBC) and glycidyl methacrylate (GMA), was carried out. TNBS colorimetric assay, 1H-NMR and ATR-FTIR confirmed covalent and tunable functionalization of collagen lysines. Depending on the type and extent of functionalization, controlled stability and thermal denaturation of triple helices were observed via circular dichroism (CD), whereby the hydrogen-bonding capability of introduced moieties was shown to play a major role. Full gel formation was observed following photo-activation of functionalized collagen solutions. The presence of a covalent network only slightly affected collagen triple helix conformation (as observed by WAXS and ATR-FTIR), confirming the structural organization of fun...

  5. New analysis of the phylogenetic change of collagen thermostability.

    Science.gov (United States)

    Burjanadze, T V

    2000-05-01

    Recent data concerning the thermostability and the primary structure of type IV collagens, some invertebrate collagens, and for the stability of synthetic collagen-like polypeptides, show that our earlier analysis of the phylogenetic change of thermostability has some shortcomings. The results of the analysis were corrected and it has been shown that the dependence of denaturation temperature Td on 4-hydroxyproline content is hyperbolic and the total Gly-Pro-Hyp sequence content is a main, but not exclusive, factor influencing the change of collagen thermostability. It appears possible that the same mechanism underlies the thermostability of fibril-forming collagens of all animal life, ranging from Antarctic ice fish to at least one annelid (Alvinella pompejana) living at very high temperatures at the bottom of the ocean near thermal vents.

  6. The effect of various avocado oils on skin collagen metabolism.

    Science.gov (United States)

    Werman, M J; Mokady, S; Nimni, M E; Neeman, I

    1991-01-01

    The effects of various avocado oils on collagen metabolism in skin were studied in growing rats fed diets containing 10% (w/w) of the tested oils. Rats fed the unrefined avocado oil extracted with hexane from the intact fruit, its unsaponifiables or the avocado seed oil, showed significant increases in soluble collagen content in skin, though total collagen content was not affected. The increased soluble collagen content appears to be a consequence of the inhibition of lysyl oxidase activity. The active factor was found to be present in the unrefined avocado oil and probably originated from the avocado seed, since collagen metabolism was affected only by fractions which contained lipids fraction from the seed. In comparison rats fed the refined or unrefined soybean oils showed no effects.

  7. Expression and distribution of type VI collagen in gynecomastia.

    Science.gov (United States)

    Lanzafame, S; Magro, G; Colombatti, A

    1994-06-01

    We investigated the distribution of type VI collagen in 36 cases of routinely fixed and paraffin-embedded gynecomastia using an immunoperoxidase method for light microscopic visualization. Four samples of normal male mammary gland tissue were also included as controls. A protease predigestion was essential for the visualization of this extracellular matrix (ECM) glycoprotein. In normal male breast, no immunoreaction for type VI collagen was detected in the stroma surrounding the ducts. Gynecomastia was classified into three histological types: florid (type I), fibrous (type II), and intermediate (type III). Type VI collagen was differentially expressed in the periductal stroma of all types. This collagen was markedly expressed at the early disease stage (type I) when the periductal stroma is highly cellular and vascular. Its expression decreased when periductal stroma undergoing fibrotic transformation (type III) and completely disappeared from the dense periductal stroma of fibrous stage (type II). These findings suggest that type VI collagen is involved in the ECM remodelling occurring in gynecomastia.

  8. Collagen matrix as a tool in studying fibroblastic cell behavior

    Science.gov (United States)

    Kanta, Jiří

    2015-01-01

    Type I collagen is a fibrillar protein, a member of a large family of collagen proteins. It is present in most body tissues, usually in combination with other collagens and other components of extracellular matrix. Its synthesis is increased in various pathological situations, in healing wounds, in fibrotic tissues and in many tumors. After extraction from collagen-rich tissues it is widely used in studies of cell behavior, especially those of fibroblasts and myofibroblasts. Cells cultured in a classical way, on planar plastic dishes, lack the third dimension that is characteristic of body tissues. Collagen I forms gel at neutral pH and may become a basis of a 3D matrix that better mimics conditions in tissue than plastic dishes. PMID:25734486

  9. Cervical Collagen Concentration within Fifteen Months after Delivery

    DEFF Research Database (Denmark)

    Sundtoft, Iben; Uldbjerg, Niels; Sommer, Steffe

    2011-01-01

    OBJECTIVE: Cervical collagen concentration decreases during pregnancy. The increased risk of preterm birth following a short interpregnancy interval may be explained by an incomplete remodeling of the cervix. The objective of this study was to describe the changes in cervical collagen concentration...... over 15 months following delivery. METHODS: The collagen concentrations were determined in cervical biopsies obtained from 15 women at 3, 6, 9, 12, and 15 months after delivery. RESULTS: The mean cervical collagen concentrations were 50, 59, 63, 65, and 65 % of dry weight (SD 4.2 – 6.5). This increase...... was statistically significant until month 9, but not between months 9 and 12. CONCLUSIONS: Low collagen concentrations in the uterine cervix may contribute to the association between a short interpregnancy interval and preterm birth....

  10. [Moisture sorption of gelatin powder and collagen fibers].

    Science.gov (United States)

    Boki, K; Kawasaki, N; Minami, K

    1994-09-01

    Moisture sorption properties of gelatin powder and collagen fibers were investigated on the basis of the moisture sorption isotherm, the differential heat of moisture sorption, the decrease in entropy of moisture sorption and the parameter constants of the applicable isotherm equation. The amount of moisture sorbed on collagen fibers was larger than that on gelatin powder. The water molecules were absorbed on gelatin itself rather than on the active sites of gelatin. They were adsorbed on the polar groups of constitutive amino acids at amounts of moisture sorbed up to one or two monolayers and then were absorbed into collagen fibers at higher monolayers. They were kept loosely in gelatin and tightly in collagen. The structural stability of collagen to moisture was higher than that of gelatin.

  11. Incorporation of Collagen in Calcium Phosphate Cements for Controlling Osseointegration

    Directory of Open Access Journals (Sweden)

    Ming-Hsien Hu

    2017-08-01

    Full Text Available In this study, we investigated the effect of supplementing a non-dispersive dicalcium phosphate-rich calcium phosphate bone cement (DCP-rich CPC with type I collagen on in vitro cellular activities and its performance as a bone graft material. Varying amounts of type I collagen were added during the preparation of the DCP-rich CPC. In vitro cell adhesion, morphology, viability, and alkaline phosphatase (ALP activity were evaluated using progenitor bone cells. Bone graft performance was evaluated via a rat posterolateral lumbar fusion model and osteointegration of the implant. New bone formations in the restorative sites were assessed by micro-computed tomography (micro-CT and histological analysis. We found that the incorporation of collagen into the DCP-rich CPC was associated with increased cell adhesion, cell viability, and ALP activity in vitro. The spinal fusion model revealed a significant increase in bone regeneration. Additionally, better osseointegration was observed between the host bone and graft with the DCP-rich CPC supplemented with collagen than with the collagen-free DCP-rich CPC control graft. Furthermore, compared to the control graft, the results of micro-CT showed that a smaller amount of residual material was observed with the collagen-containing DCP-rich CPC graft compared with the control graft, which suggests the collagen supplement enhanced new bone formation. Of the different mixtures evaluated in this study (0.8 g DCP-rich CPC supplemented with 0.1, 0.2, and 0.4 mL type I collagen, respectively, DCP-rich CPC supplemented with 0.4 mL collagen led to the highest level of osteogenesis. Our results suggest that the DCP-rich CPC supplemented with collagen has potential to be used as an effective bone graft material in spinal surgery.

  12. Lysyl oxidases regulate fibrillar collagen remodelling in idiopathic pulmonary fibrosis

    Science.gov (United States)

    White, Eric S.

    2017-01-01

    ABSTRACT Idiopathic pulmonary fibrosis (IPF) is a progressive scarring disease of the lung with few effective therapeutic options. Structural remodelling of the extracellular matrix [i.e. collagen cross-linking mediated by the lysyl oxidase (LO) family of enzymes (LOX, LOXL1-4)] might contribute to disease pathogenesis and represent a therapeutic target. This study aimed to further our understanding of the mechanisms by which LO inhibitors might improve lung fibrosis. Lung tissues from IPF and non-IPF subjects were examined for collagen structure (second harmonic generation imaging) and LO gene (microarray analysis) and protein (immunohistochemistry and western blotting) levels. Functional effects (collagen structure and tissue stiffness using atomic force microscopy) of LO inhibitors on collagen remodelling were examined in two models, collagen hydrogels and decellularized human lung matrices. LOXL1/LOXL2 gene expression and protein levels were increased in IPF versus non-IPF. Increased collagen fibril thickness in IPF versus non-IPF lung tissues correlated with increased LOXL1/LOXL2, and decreased LOX, protein expression. β-Aminoproprionitrile (β-APN; pan-LO inhibitor) but not Compound A (LOXL2-specific inhibitor) interfered with transforming growth factor-β-induced collagen remodelling in both models. The β-APN treatment group was tested further, and β-APN was found to interfere with stiffening in the decellularized matrix model. LOXL1 activity might drive collagen remodelling in IPF lungs. The interrelationship between collagen structural remodelling and LOs is disrupted in IPF lungs. Inhibition of LO activity alleviates fibrosis by limiting fibrillar collagen cross-linking, thereby potentially impeding the formation of a pathological microenvironment in IPF. PMID:29125826

  13. Lysyl oxidases regulate fibrillar collagen remodelling in idiopathic pulmonary fibrosis.

    Science.gov (United States)

    Tjin, Gavin; White, Eric S; Faiz, Alen; Sicard, Delphine; Tschumperlin, Daniel J; Mahar, Annabelle; Kable, Eleanor P W; Burgess, Janette K

    2017-11-01

    Idiopathic pulmonary fibrosis (IPF) is a progressive scarring disease of the lung with few effective therapeutic options. Structural remodelling of the extracellular matrix [i.e. collagen cross-linking mediated by the lysyl oxidase (LO) family of enzymes (LOX, LOXL1-4)] might contribute to disease pathogenesis and represent a therapeutic target. This study aimed to further our understanding of the mechanisms by which LO inhibitors might improve lung fibrosis. Lung tissues from IPF and non-IPF subjects were examined for collagen structure (second harmonic generation imaging) and LO gene (microarray analysis) and protein (immunohistochemistry and western blotting) levels. Functional effects (collagen structure and tissue stiffness using atomic force microscopy) of LO inhibitors on collagen remodelling were examined in two models, collagen hydrogels and decellularized human lung matrices. LOXL1/LOXL2 gene expression and protein levels were increased in IPF versus non-IPF. Increased collagen fibril thickness in IPF versus non-IPF lung tissues correlated with increased LOXL1/LOXL2, and decreased LOX, protein expression. β-Aminoproprionitrile (β-APN; pan-LO inhibitor) but not Compound A (LOXL2-specific inhibitor) interfered with transforming growth factor-β-induced collagen remodelling in both models. The β-APN treatment group was tested further, and β-APN was found to interfere with stiffening in the decellularized matrix model. LOXL1 activity might drive collagen remodelling in IPF lungs. The interrelationship between collagen structural remodelling and LOs is disrupted in IPF lungs. Inhibition of LO activity alleviates fibrosis by limiting fibrillar collagen cross-linking, thereby potentially impeding the formation of a pathological microenvironment in IPF. © 2017. Published by The Company of Biologists Ltd.

  14. Endoplasmic reticulum stress inhibits collagen synthesis independent of collagen-modifying enzymes in different chondrocyte populations and dermal fibroblasts

    NARCIS (Netherlands)

    Vonk, Lucienne A.; Doulabi, Behrouz Zandieh; Huang, Chun-Ling; Helder, Marco N.; Everts, Vincent; Bank, Ruud A.

    Chondrocytes respond to glucose deprivation with a decreased collagen synthesis due to disruption of a proper functioning of the endoplasmic reticulum (ER): ER stress. Since the mechanisms involved in the decreased synthesis are unknown, we have investigated whether chaperones and collagen-modifying

  15. Endoplasmic reticulum stress inhibits collagen synthesis independent of collagen-modifying enzymes in different chondrocyte populations and dermal fibroblasts

    NARCIS (Netherlands)

    Vonk, L.A.; Doulabi, B.Z.; Huang, C.L.; Helder, M.N.; Everts, V.; Bank, R.A.

    2010-01-01

    Chondrocytes respond to glucose deprivation with a decreased collagen synthesis due to disruption of a proper functioning of the endoplasmic reticulum (ER): ER stress. Since the mechanisms involved in the decreased synthesis are unknown, we have investigated whether chaperones and collagen-modifying

  16. Picrosirius red staining assessment of collagen after dermal roller application: A minimally invasive percutaneous collagen induction therapy

    Directory of Open Access Journals (Sweden)

    Fatma El-Zahraa Salah El-Deen Yassin

    2014-01-01

    Full Text Available Background: Percutaneous collagen induction (PCI through dermal roller breaks old collagen strands, promotes removal of damaged collagen and induces more collagen formation. Collagen fibers can be assessed by traditional stains or by polarized light assessment of Picrosirius red stain. Objective: The purpose of the current study is the clinical and histopathological evaluation of percutaneous collagen formation in atrophic acne scars after dermal roller application. Patients and Methods: Total study duration was 26 weeks in which 12 patients received seven sessions of PCI at 3-weeks interval, 3 mm punch biopsy specimens of scars were obtained before and after treatment (at 18 and 26 weeks. Microscopic examination of pre and post operative biopsies were done, using routine stains and Picrosirius red stain. Results: PCI induced notable improvement in the appearance of acne scars with significant reduction in the score from 123.3 ± 24.5 to 74.16 ± 16.49 (P = 0.00 after 26 weeks. Polarized light assessment of Picrosirius red stain clarified the gradual replacement of old thick orange-red birefringent collagen fibers by newly synthesized thin green-yellow birefringent ones postoperatively. Conclusion: Skin needling is a simple and minimally invasive procedure. The polarized light assessment of Picrosirius red stain clarified the change of the optical properties of collagen fibers according to the maturation process.

  17. Small-bowel permeability in collagenous colitis

    DEFF Research Database (Denmark)

    Wildt, Signe; Madsen, Jan L; Rumessen, Jüri J

    2006-01-01

    OBJECTIVE: Collagenous colitis (CC) is a chronic inflammatory bowel disease that affects the colon. However, some patients with CC present with accompanying pathologic small-bowel manifestations such as coeliac disease, defects in bile acid absorption and histopathologic changes in small...... permeability. MATERIAL AND METHODS: Ten patients with CC and chronic diarrhoea participated in the study. Coeliac disease was excluded by small-bowel biopsy and/or serology. Intestinal permeability was assessed as urinary excretion (ratios) 2, 4 and 6 h after ingestion of 14C-labelled mannitol (14C......-intestinal biopsies, indicating that CC is a pan-intestinal disease. In small-intestinal disease, the intestinal barrier function may be impaired, and the permeability of the small intestine altered. The purpose of this research was to study small-bowel function in patients with CC as expressed by intestinal...

  18. [Treatment of keratoconus by collagen cross linking].

    Science.gov (United States)

    Wollensak, G; Spörl, E; Seiler, T

    2003-01-01

    We were able to show a significant increase in corneal stiffness of rabbit and porcine eyes after combined riboflavin/UVA-induced collagen cross-linking. In this study,we tried to treat keratoconus patients with this method to stop the progression of corneal ectasia. We treated 16 eyes of 15 patients with progressive keratoconus and mostly moderate keratectasia (48-56 dpt). After removal of the epithelium (7 mm X), riboflavin solution was applied on the cornea, which was irradiated with UVA (370 nm,3 mW/cm(2)) at a distance of 1 cm for 30 min.Post-operative follow-up controls were conducted every 3 months in the first year and then every 6 months, always including visual acuity testing, corneal topography and measurements of endothelial cell density. The follow-up time was between 1 and 3 years. Progression of keratectasia was stopped in all patients. Best corrected visual acuity and the maximal keratometry values improved slightly in about 50% of the cases. In all patients corneal transparency, the degree of keratectasia registered by corneal topography and the density of endothelial cells remained unchanged within the follow-up time. No negative side-effects were observed. Our results show that collagen cross linking might be a useful conservative treatment modality to stop the progression of keratoconus. By this means the need for keratoplasty might be significantly reduced. Given the simplicity of the technique and minimal costs of the treatment it might also be well suited for developing countries.Further studies are envisaged to exclude long-term side effects and to evaluate the long term durability of the mechanical stiffness effect.

  19. High-strength mineralized collagen artificial bone

    Science.gov (United States)

    Qiu, Zhi-Ye; Tao, Chun-Sheng; Cui, Helen; Wang, Chang-Ming; Cui, Fu-Zhai

    2014-03-01

    Mineralized collagen (MC) is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal's cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in vivo implantation assay demonstrated good biocompatibility of the material, and in vivo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load-bearing sites.

  20. Isolation and Characterization of Collagen and Antioxidant Collagen Peptides from Scales of Croceine Croaker (Pseudosciaena crocea

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2013-11-01

    Full Text Available Acid soluble collagen (ASC from scales of croceine croaker (ASC-C was successfully isolated with the yield of 0.37% ± 0.08% (dry weight basis, and characterized as type I collagen on the basis of amino acid analysis and electrophoretic pattern. The antioxidant hydrolysate of ASC-C (ACH was prepared through a two-stage in vitro digestion (4-h trypsin followed by 4-h pepsin, and three antioxidant peptides (ACH-P1, ACH-P2, and ACH-P3 were further isolated from ACH using ultrafiltration, gel chromatography, and RP-HPLC, and their amino acid sequences were identified as GFRGTIGLVG (ACH-P1, GPAGPAG (ACH-P2, and GFPSG (ACH-P3. ACH-P1, ACH-P2, and ACH-P3 showed good scavenging activities on hydroxyl radical (IC50 0.293, 0.240, and 0.107 mg/mL, respectively, DPPH radical (IC50 1.271, 0.675, and 0.283 mg/mL, respectively, superoxide radical (IC50 0.463, 0.099, and 0.151 mg/mL, respectively, and ABTS radical (IC50 0.421, 0.309, and 0.210 mg/mL, respectively. ACH-P3 was also effectively against lipid peroxidation in the model system. The antioxidant activities of three collagen peptides were due to the presence of hydrophobic amino acid residues within the peptide sequences. The collagen peptides might be used as antioxidant for the therapy of diseases associated with oxidative stress, or reducing oxidative changes during storage.

  1. Visualisation of Collagen in fixed skeletal muscle tissue using fluorescently tagged Collagen binding protein CNA35.

    Science.gov (United States)

    Mohammadkhah, Melika; Simms, Ciaran K; Murphy, Paula

    2017-02-01

    Detection and visualisation of Collagen structure are important to understand the relationship between mechanical behaviour and microstructure in skeletal muscle since Collagen is the main structural protein in animal connective tissues, and is primarily responsible for their passive load-bearing properties. In the current study, the direct detection and visualization of Collagen using fluorescently tagged CNA35 binding protein (fused to EGFP or tdTomato) is reported for the first time on fixed skeletal muscle tissue. This Technical Note also establishes a working protocol by examining tissue preparation, dilution factor, exposure time etc. for sensitivity and specificity. Penetration of the binding protein into intact mature skeletal muscle was found to be very limited, but detection works well on tissue sections with higher sensitivity on wax embedded sections compared to frozen sections. CNA35 fused to tdTomato has a higher sensitivity than CNA35 fused to EGFP but both show specific detection. Best results were obtained with 15μm wax embedded sections, with blocking of non-specific binding in 1% BSA and antigen retrieval in Sodium Citrate. There was a play-off between dilution of the binding protein and time of incubation but both CNA35-tdTomato and CNA35-EGFP worked well with approximately 100μg/ml of purified protein with overnight incubation, while CNA35-tdTomato could be utilized at 5 fold less concentration. This approach can be applied to study the relationship between skeletal muscle micro-structure and to observe mechanical response to applied deformation. It can be used more broadly to detect Collagen in a variety of fixed tissues, useful for structure-functions studies, constitutive modelling, tissue engineering and assessment of muscle tissue pathologies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Effects of Immobilized BMP-2 and Nanofiber Morphology on In Vitro Osteogenic Differentiation of hMSCs and In Vivo Collagen Assembly of Regenerated Bone.

    Science.gov (United States)

    Perikamana, Sajeesh Kumar Madhurakkat; Lee, Jinkyu; Ahmad, Taufiq; Jeong, Yonghoon; Kim, Do-Gyoon; Kim, Kyobum; Shin, Heungsoo

    2015-04-29

    Engineering bone tissue is particularly challenging because of the distinctive structural features of bone within a complex biochemical environment. In the present study, we fabricated poly(L-lactic acid) (PLLA) electrospun nanofibers with random and aligned morphology immobilized with bone morphogenic protein-2 (BMP-2) and investigated how these signals modulate (1) in vitro osteogenic differentiation of human mesenchymal stem cells (hMSCs) and (2) in vivo bone growth rate, mechanical properties, and collagen assembly of newly formed bone. The orientation of adherent cells followed the underlying nanofiber morphology; however, nanofiber alignment did not show any difference in alkaline phosphate activity or in calcium mineralization of hMSCs after 14 days of in vitro culture in osteogenic differentiation media. In vivo bone regeneration was significantly higher in the nanofiber implanted groups (approximately 65-79%) as compared to the defect-only group (11.8 ± 0.2%), while no significant difference in bone regeneration was observed between random and aligned groups. However, nanoindentation studies of regenerated bone revealed Young's modulus and contact hardness with anisotropic feature for aligned group as compared to random group. More importantly, structural analysis of collagen at de novo bone showed the ability of nanofiber morphology to guide collagen deposition. SEM and TEM images revealed regular, highly ordered collagen assemblies on aligned nanofibers as compared to random fibers, which showed irregular, randomly organized collagen deposition. Taken together, we conclude that nanofibers in the presence of osteoinductive signals are a potent tool for bone regeneration, and nanofiber alignment can be used for engineering bone tissues with structurally assembled collagen fibers with defined direction.

  3. The Initiator Methionine tRNA Drives Secretion of Type II Collagen from Stromal Fibroblasts to Promote Tumor Growth and Angiogenesis.

    Science.gov (United States)

    Clarke, Cassie J; Berg, Tracy J; Birch, Joanna; Ennis, Darren; Mitchell, Louise; Cloix, Catherine; Campbell, Andrew; Sumpton, David; Nixon, Colin; Campbell, Kirsteen; Bridgeman, Victoria L; Vermeulen, Peter B; Foo, Shane; Kostaras, Eleftherios; Jones, J Louise; Haywood, Linda; Pulleine, Ellie; Yin, Huabing; Strathdee, Douglas; Sansom, Owen; Blyth, Karen; McNeish, Iain; Zanivan, Sara; Reynolds, Andrew R; Norman, Jim C

    2016-03-21

    Expression of the initiator methionine tRNA (tRNAi(Met)) is deregulated in cancer. Despite this fact, it is not currently known how tRNAi(Met) expression levels influence tumor progression. We have found that tRNAi(Met) expression is increased in carcinoma-associated fibroblasts, implicating deregulated expression of tRNAi(Met) in the tumor stroma as a possible contributor to tumor progression. To investigate how elevated stromal tRNAi(Met) contributes to tumor progression, we generated a mouse expressing additional copies of the tRNAi(Met) gene (2+tRNAi(Met) mouse). Growth and vascularization of subcutaneous tumor allografts was enhanced in 2+tRNAi(Met) mice compared with wild-type littermate controls. Extracellular matrix (ECM) deposited by fibroblasts from 2+tRNAi(Met) mice supported enhanced endothelial cell and fibroblast migration. SILAC mass spectrometry indicated that elevated expression of tRNAi(Met) significantly increased synthesis and secretion of certain types of collagen, in particular type II collagen. Suppression of type II collagen opposed the ability of tRNAi(Met)-overexpressing fibroblasts to deposit pro-migratory ECM. We used the prolyl hydroxylase inhibitor ethyl-3,4-dihydroxybenzoate (DHB) to determine whether collagen synthesis contributes to the tRNAi(Met)-driven pro-tumorigenic stroma in vivo. DHB had no effect on the growth of syngeneic allografts in wild-type mice but opposed the ability of 2+tRNAi(Met) mice to support increased angiogenesis and tumor growth. Finally, collagen II expression predicts poor prognosis in high-grade serous ovarian carcinoma. Taken together, these data indicate that increased tRNAi(Met) levels contribute to tumor progression by enhancing the ability of stromal fibroblasts to synthesize and secrete a type II collagen-rich ECM that supports endothelial cell migration and angiogenesis. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Activation of PPARs α, β/δ, and γ Impairs TGF-β1-Induced Collagens' Production and Modulates the TIMP-1/MMPs Balance in Three-Dimensional Cultured Chondrocytes

    Directory of Open Access Journals (Sweden)

    Paul-Emile Poleni

    2010-01-01

    Full Text Available Background and Purpose. We investigated the potency of Peroxisome Proliferators-Activated Receptors (PPARs α, β/δ, and γ agonists to modulate Transforming Growth Factor-β1 (TGF-β1- induced collagen production or changes in Tissue Inhibitor of Matrix Metalloproteinase- (TIMP- 1/Matrix Metalloproteinase (MMP balance in rat chondrocytes embedded in alginate beads. Experimental Approach. Collagen production was evaluated by quantitative Sirius red staining, while TIMP-1 protein levels and global MMP (-1, -2, -3, -7, and -9 or specific MMP-13 activities were measured by ELISA and fluorigenic assays in culture media, respectively. Levels of mRNA for type II collagen, TIMP-1, and MMP-3 & 13 were quantified by real-time PCR. Key Results. TGF-β1 increased collagen deposition and type II collagen mRNA levels, while inducing TIMP-1 mRNA and protein expression. In contrast, it decreased global MMP or specific MMP-13 activities, while decreasing MMP-3 or MMP-13 mRNA levels. PPAR agonists reduced most of the effects of TGF-β1 on changes in collagen metabolism and TIMP-1/MMP balance in rat in a PPAR-dependent manner, excepted for Wy14643 on MMP activities. Conclusions and Implications. PPAR agonists reduce TGF-β1-modulated ECM turnover and inhibit chondrocyte activities crucial for collagen biosynthesis, and display a different inhibitory profile depending on selectivity for PPAR isotypes.

  5. Activation of PPARs α, β/δ, and γ Impairs TGF-β1-Induced Collagens' Production and Modulates the TIMP-1/MMPs Balance in Three-Dimensional Cultured Chondrocytes

    Science.gov (United States)

    Poleni, Paul-Emile; Etienne, Stephanie; Velot, Emilie; Netter, Patrick; Bianchi, Arnaud

    2010-01-01

    Background and Purpose. We investigated the potency of Peroxisome Proliferators-Activated Receptors (PPARs) α, β/δ, and γ agonists to modulate Transforming Growth Factor-β1 (TGF-β1-) induced collagen production or changes in Tissue Inhibitor of Matrix Metalloproteinase- (TIMP-) 1/Matrix Metalloproteinase (MMP) balance in rat chondrocytes embedded in alginate beads. Experimental Approach. Collagen production was evaluated by quantitative Sirius red staining, while TIMP-1 protein levels and global MMP (-1, -2, -3, -7, and -9) or specific MMP-13 activities were measured by ELISA and fluorigenic assays in culture media, respectively. Levels of mRNA for type II collagen, TIMP-1, and MMP-3 & 13 were quantified by real-time PCR. Key Results. TGF-β1 increased collagen deposition and type II collagen mRNA levels, while inducing TIMP-1 mRNA and protein expression. In contrast, it decreased global MMP or specific MMP-13 activities, while decreasing MMP-3 or MMP-13 mRNA levels. PPAR agonists reduced most of the effects of TGF-β1 on changes in collagen metabolism and TIMP-1/MMP balance in rat in a PPAR-dependent manner, excepted for Wy14643 on MMP activities. Conclusions and Implications. PPAR agonists reduce TGF-β1-modulated ECM turnover and inhibit chondrocyte activities crucial for collagen biosynthesis, and display a different inhibitory profile depending on selectivity for PPAR isotypes. PMID:20981144

  6. Collagen/Polypropylene composite mesh biocompatibility in abdominal wall reconstruction.

    Science.gov (United States)

    Lukasiewicz, Aleksander; Skopinska-Wisniewska, Joanna; Marszalek, Andrzej; Molski, Stanislaw; Drewa, Tomasz

    2013-05-01

    Intraperitoneal placement of polypropylene mesh leads to extensive visceral adhesions and is contraindicated. Different coatings are used to improve polypropylene mesh properties. Collagen is a protein with unique biocompatibility and cell ingrowth enhancement potential. A novel acetic acid extracted collagen coating was developed to allow placement of polypropylene mesh in direct contact with viscera. The authors' aim was to evaluate the long-term influence of acetic acid extracted collagen coating on surgical aspects and biomechanical properties of polypropylene mesh implanted in direct contact with viscera, including complications, adhesions with viscera, strength of incorporation, and microscopic inflammatory reaction. Forty adult Wistar rats were divided into two groups: experimental (polypropylene mesh/acetic acid extracted collagen coating) and control (polypropylene mesh only). Astandardized procedure of mesh implantation was performed. Animals were killed 3 months after surgery and analyzed for complications, mesh area covered by adhesions, type of adhesions, strength of incorporation, and intensity of inflammatory response. The mean adhesion area was lower for polypropylene mesh/acetic acid extracted collagen coating (14.5 percent versus 69.9 percent, p polypropylene mesh are significantly reduced because of acetic acid extracted collagen coating. The collagen coating does not increase complications or induce alterations of polypropylene mesh incorporation.

  7. Extraction and Characterization of Collagen from Sea Cucumber Flesh

    Directory of Open Access Journals (Sweden)

    Alhana

    2015-11-01

    Full Text Available Sea cucumber (Stichopus variegatus is one of the Echinodermata phylum that grows along Indonesian coastal. Sea cucumber is potential source of collagen. The purposes of this research were to determine the optimal concentration of NaOH and CH3COOH solution in collagen production and analyze the physicochemical characteristics of collagen from S. variegatus. Yield of the collagen was 1.5% (based on wet weight basis, produced by pretreatment with NaOH 0,30%, hydrolysis with CH3COOH 0.10% and extracted using distilled water. Protein, moisture, and ash content of the collagen was 67.68%, 13.64%, and 4.15%, respectively. Collagen was extracted using distilled water at 45°C during 2h and still had triple helix structure ; pH 7.37 ; melting temperature 163.67°C and whiteness 69.25%. The major amino acid content of collagen were glycine, alanine, proline and glutamic acid.

  8. Imaging cells in three-dimensional collagen matrix.

    Science.gov (United States)

    Artym, Vira V; Matsumoto, Kazue

    2010-09-01

    The use of in vitro three-dimensional (3-D) collagen matrices to mimic an in vivo cellular environment has become increasingly popular and is broadening our understanding of cellular processes and cell-ECM interactions. To study cells in in vitro 3-D collagen matrices, both cellular proteins and the collagen matrix must be visualized. In this unit, the authors describe the protocol and provide troubleshooting for immunolabeling of cells in 3-D collagen gels to localize and visualize cellular proteins with high-resolution fluorescence confocal microscopy. The authors then describe confocal reflection microscopy as a technique for direct imaging of 3-D fibrillar collagen matrices by discussing the advantages and disadvantages of the technique. They also provide instrument settings required for simultaneous imaging of cellular proteins with fluorescence confocal imaging and 3-D collagen fibrils with confocal reflection microscopy. Additionally, the authors provide protocols for a "cell sandwiching" technique to prepare cell cultures in 3-D collagen matrices required for high-resolution confocal imaging. © 2010 by John Wiley & Sons, Inc.

  9. Osteocalcin/fibronectin-functionalized collagen matrices for bone tissue engineering.

    Science.gov (United States)

    Kim, S G; Lee, D S; Lee, S; Jang, J-H

    2015-06-01

    Collagen is the most abundant protein found in the extracellular matrix and is widely used to build scaffolds for biomedical applications which are the result of its biocompatibility and biodegradability. In the present study, we constructed a rhOCN/FNIII9-10 fusion protein and rhOCN/FNIII9-10-functionalized collagen matrices and investigated the potential value for bone tissue engineering. In vitro studies carried out with preosteoblastic MC3T3-E1 cells showed that rhOCN/FNIII9-10 fusion protein promoted cell adhesion and the mRNA levels of osteogenic markers including osteocalcin, runt-related transcription factor 2, alkaline phosphatase (ALP), and collagen type I. In addition, rhOCN/FNIII9-10-functionalized collagen matrices showed significant induction of the ALP activity more than rhFNIII9-10-functionalized collagen matrices or collagen matrices alone. These results suggested that rhOCN/FNIII9-10-functionalized collagen matrices have potential for bone tissue engineering. © 2014 Wiley Periodicals, Inc.

  10. [Collagen types ratio in prediction of postoperative ventral hernias].

    Science.gov (United States)

    Lazarenko, V A; Ivanov, S V; Ivanov, I S; Rosberg, E P; Tsukanov, A V; Popova, L P; Tarabrin, D V; Obyedkov, E G

    To analyze collagen types ratio in skin and aponeurosis in order to predict postoperative ventral hernias. The trial included 141 patients for the period 2012-2015. Group I (n=65) of patients without ventral hernias was divided into subgroup AI (primary operation, n=41) and BI (re-operation, n=24). Group II consisted of 76 patients with ventral hernias. We performed histological examination of skin and aponeurosis to define the collagen structure of connective tissue. There were significant differences between collagen type I/III ratio in skin (2.81±0.52 in group I vs. 1.13±0.48 in group II) and aponeurosis (2.69±0.41 vs. 1.09±0.21, respectively, p≤0.05). We revealed strong direct correlation (r=+0.92) between aponeurosis and skin specimens in one group. Collagen type I level was 73.81±2.74% in subgroup AI and 72.03±2.47% in subgroup BI. Collagen type I was predominant (p≤0.05). In patients with ventral hernias collagen type I/III ratio in skin is 2.54 times lower than in patients without hernias. Significant correlation of collagen types in skin and aponeurosis (r= +0.92) allows to predict the risk of postoperative ventral hernias on basis of skin fragment.

  11. Testosterone delays vascular smooth muscle cell senescence and inhibits collagen synthesis via the Gas6/Axl signaling pathway.

    Science.gov (United States)

    Chen, Yan-qing; Zhao, Jing; Jin, Cheng-wei; Li, Yi-hui; Tang, Meng-xiong; Wang, Zhi-hao; Zhang, Wei; Zhang, Yun; Li, Li; Zhong, Ming

    2016-06-01

    Testosterone deficiency is associated with a higher incidence of cardiovascular diseases in men. However, its effect on cell senescence, which plays a causal role in vascular aging, remains unclear. Here, we tested the hypothesis that testosterone alleviated vascular smooth muscle cell (VSMC) senescence and collagen synthesis via growth arrest-specific protein 6 (Gas6)/Axl- and Akt/FoxO1a-dependent pathways. Testosterone significantly ameliorated angiotensin II-induced VSMC senescence and collagen overexpression. In addition, testosterone inhibited angiotensin II-induced matrix metalloproteinase-2 (MMP-2) activity, which played a pivotal role in facilitating age-related collagen deposition. Testosterone increased the expression of tissue inhibitor of metalloproteinase-2 but decreased the expression of MMP-2 and membrane type-1 metalloproteinase which contributed to increase MMP-2 activity. The effects on VSMCs senescence and collagen synthesis were mediated by restoration of angiotensin II-induced downregulation of Gas6 and Axl expression and a subsequent reduction of Akt and FoxO1a phosphorylation. The effects of testosterone were reversed by a Gas6 blocker, Axl-Fc, and a specific inhibitor of Axl, R428. Treatment of VSMCs with PI3K inhibitor LY294002 abrogated the downregulating effect of testosterone on MMP-2 activity. Furthermore, when FoxO1a expression was silenced by using a specific siRNA, the inhibitory effect of testosterone on MMP-2 activity was revered as well, that indicated this process was Akt/FoxO1a dependence. Taken together, Gas6/Axl and Akt/FoxO1a were involved in protective effects of testosterone on VSMCs senescence and collagen synthesis. Our results provide a novel mechanism underlying the protective effect of testosterone on vascular aging and may serve as a theoretical basis for testosterone replacement therapy.

  12. [A particular type of cicatricial Pemphigoid with unique IgA deposit].

    Science.gov (United States)

    Aounallah, Amina; Jrad, Mariem; Ksiaa, Mehdi; Mokni, Sana; Saidi, Wafa; Boussofara, Lobna; Sriha, Badreddine; Denguezli, Mohamed; Ghariani, Najet; Belajouza, Colandane; Nouira, Rafia

    2017-01-01

    Cicatricial Pemphigoid is a subepithelial bullous dermatosis which essentially involves the mucous membranes with cicatricial evolution We report the case of a 66-year old patient hospitalized with erosive gingivitis associated with dysphagia, dyspnea and blurred vision. Dermatologic examination showed erosive lesions involving the palate and the pharynx. Ophthalmologic examination showed symblepharons, ectropion and bilateral cataract. Gingival biopsy revealed a necrotic detachment of the buccal epithelium. Direct immunofluorescence showed linear IgA deposit at the dermo-epidermal junction. Indirect immunofluorescence test was negative. The diagnosis of cicatricial pemphigoid was confirmed. Esophagogastroduodenoscopy objectified double stenosis of the esophagus. Nasopharyngeal and bronchial endoscopy showed ulceration of the epiglottis, hypopharynx, pharynx and bronchial tree. The patient was treated with Solumedrol bolus corresponding to 0.5mg/kg/day prednisone associated with 100mg/day disulone. The patient showed a favorable early clinical outcome complicated because of the aggravation of dysphagia and esophageal stenosis after 2 months. Our case study is singular due to the occurrence of a cicatricial pemphigoid in a male patient with a serious clinical picture due to lesions extending to conjunctival, oral, nasal, esophageal and bronchial mucous membranes associated with direct immunofluorescence only showing IgA deposit.

  13. Crescentic glomerulonephritis and subepidermal blisters with autoantibodies to alpha5 and alpha6 chains of type IV collagen.

    Science.gov (United States)

    Ghohestani, Reza F; Rotunda, Sherry L; Hudson, Billy; Gaughan, William J; Farber, John L; Webster, Guy; Uitto, Jouni

    2003-05-01

    We describe a novel autoimmune disease characterized by severe subepidermal bullous eruption and crescentic glomerulonephritis with autoantibodies directed against the noncollagenous domain of the alpha5 and alpha6 chains of type IV collagen. Biopsy of perilesional skin revealed a subepidermal blister with marked polymorphonuclear infiltrate with linear deposits of IgA and C3. Light microscopy of a kidney biopsy specimen revealed a crescentic glomerulonephritis, and immunofluorescence microscopy showed linear basement membrane staining for IgA (3+), C3 (1+), and IgG (1+). No electron-dense deposits were observed by transmission electron microscopy. The patient's autoantibodies reacted with normal human skin and kidney: IgA (3+) and IgG (1+) antibodies stained the basement membrane zones of skin, renal glomerulus, and some tubules. The identity of the target antigen was determined by immunochemical analyses of candidate antigens using the patient's autoantibodies. The patient's IgA and IgG autoantibodies reacted with a 185- to 190-kDa antigen from a human dermal extract that was distinguished from the other dermal or epidermal antigens, including the 145- to 290-kDa (type VII collagen) epidermolysis bullosa acquisita antigen, the 165- to 200-kDa alpha3 laminin mucous membrane cicatricial pemphigoid antigen, and the 230-kDa and the 180-kDa bullous pemphigoid antigens. Patient's IgA and IgG autoantibodies further reacted with the alpha5(IV) and weakly with the alpha6(IV) chains of type IV collagen by Western blot and ELISA. This report expands the repertoire of bullous skin disorders and provides an explanation for the association of anti-type IV collagen autoantibodies and glomerulonephritis with subepidermal blisters.

  14. Distribution of types I, II, III, IV and V collagen in normal and keratoconus corneas.

    Science.gov (United States)

    Nakayasu, K; Tanaka, M; Konomi, H; Hayashi, T

    1986-01-01

    By using type-specific antibodies to types I, II, III, IV and V collagens, distribution of distinct types of collagen in normal human cornea as well as keratoconus cornea were examined by indirect immunofluorescence microscopy. In normal human cornea, immunohistochemical evidence supported the previous biochemical finding that type I collagen was the major type of collagen in human corneal stroma. No reaction was observed to anti-type II collagen antibody in the whole cornea. Anti-type III collagen antibody reacted with the corneal stroma in a similar fashion as that of anti-type I collagen antibody. Type IV collagen was observed in the basement membrane of the corneal epithelium and in Descemet's membrane. Anti-type V collagen antibody also reacted with the corneal stroma diffusely. Bowman's membrane was strongly stained only with he anti-type V collagen antibody. For further details of the distribution of type I, type III and V collagens in human corneal stroma, immunoelectron microscopic study was undertaken. The positive reaction products of anti-type I and anti-type III collagen antibodies were located on the collagen fibrils, while that of anti-type V collagen antibody was either on or close to collagen fibrils. In keratoconus cornea, no difference was observed in terms of the distribution of type I, III and V collagens, while the disruptive and excrescent distribution of type IV collagen was noted in the basement membrane of the corneal epithelium.

  15. Collagen-like proteins in pathogenic E. coli strains.

    Directory of Open Access Journals (Sweden)

    Neelanjana Ghosh

    Full Text Available The genome sequences of enterohaemorrhagic E. coli O157:H7 strains show multiple open-reading frames with collagen-like sequences that are absent from the common laboratory strain K-12. These putative collagens are included in prophages embedded in O157:H7 genomes. These prophages carry numerous genes related to strain virulence and have been shown to be inducible and capable of disseminating virulence factors by horizontal gene transfer. We have cloned two collagen-like proteins from E. coli O157:H7 into a laboratory strain and analysed the structure and conformation of the recombinant proteins and several of their constituting domains by a variety of spectroscopic, biophysical, and electron microscopy techniques. We show that these molecules exhibit many of the characteristics of vertebrate collagens, including trimer formation and the presence of a collagen triple helical domain. They also contain a C-terminal trimerization domain, and a trimeric α-helical coiled-coil domain with an unusual amino acid sequence almost completely lacking leucine, valine or isoleucine residues. Intriguingly, these molecules show high thermal stability, with the collagen domain being more stable than those of vertebrate fibrillar collagens, which are much longer and post-translationally modified. Under the electron microscope, collagen-like proteins from E. coli O157:H7 show a dumbbell shape, with two globular domains joined by a hinged stalk. This morphology is consistent with their likely role as trimeric phage side-tail proteins that participate in the attachment of phage particles to E. coli target cells, either directly or through assembly with other phage tail proteins. Thus, collagen-like proteins in enterohaemorrhagic E. coli genomes may have a direct role in the dissemination of virulence-related genes through infection of harmless strains by induced bacteriophages.

  16. Collagen synthesized in fluorocarbon polymer implant in the rabbit cornea.

    Science.gov (United States)

    Drubaix, I; Legeais, J M; Malek-Chehire, N; Savoldelli, M; Ménasche, M; Robert, L; Renard, G; Pouliquen, Y

    1996-04-01

    The integration of microporous polymer into tissues is of great interest for the production of keratoprosthetic devices. Our previous studies showed functional differentiated cells and collagen synthesis in the pore of an expanded polytetrafluoroethylene implant. This study identifies and quantifies collagen types synthesized in the implant. Expanded polytetrafluoroethylene polymers were implanted in the rabbit corneas. The collagen extracted from the polymer and implanted stroma after 1, 3 and 6 months was quantified by measuring hydroxyproline. The relative proportions of collagen types were determined by densitometric analysis after SDS-PAGE. The collagen-to-protein ratio in the polymer increased from 0.22 to 0.70 between the first and third month after implantation becoming similar to control cornea. So that of the protein and collagen densities in the polymer and implanted stroma were similar to the control from the third month. The collagen synthesized in the polymer was mainly type I (87%) plus a small amount of type III (8%) 1 month after implantation. The collagen distribution from the third month after implantation was similar to that of the controls and remained constant thereafter in the polymer implant and in the implanted stroma. Immunogold labelling techniques confirmed these results. Implantation of this PTFE disc induced no obvious modification of the corneal stroma, confirming that this polymer is a good interface that is compatible with the native corneal stroma. The keratocytes in this polymer rapidly adopted a corneal phenotype, distinct from the dermal or scaring phenotype as shown by the collagen types produced in the implant.

  17. Collagen: A review on its sources and potential cosmetic applications.

    Science.gov (United States)

    Avila Rodríguez, María Isabela; Rodríguez Barroso, Laura G; Sánchez, Mirna Lorena

    2018-02-01

    Collagen is a fibrillar protein that conforms the conjunctive and connective tissues in the human body, essentially skin, joints, and bones. This molecule is one of the most abundant in many of the living organisms due to its connective role in biological structures. Due to its abundance, strength and its directly proportional relation with skin aging, collagen has gained great interest in the cosmetic industry. It has been established that the collagen fibers are damaged with the pass of time, losing thickness and strength which has been strongly related with skin aging phenomena [Colágeno para todo. 60 y más. 2016. http://www.revista60ymas.es/InterPresent1/groups/revistas/documents/binario/ses330informe.pdf.]. As a solution, the cosmetic industry incorporated collagen as an ingredient of different treatments to enhance the user youth and well-being, and some common presentations are creams, nutritional supplement for bone and cartilage regeneration, vascular and cardiac reconstruction, skin replacement, and augmentation of soft skin among others [J App Pharm Sci. 2015;5:123-127]. Nowadays, the biomolecule can be obtained by extraction from natural sources such as plants and animals or by recombinant protein production systems including yeast, bacteria, mammalian cells, insects or plants, or artificial fibrils that mimic collagen characteristics like the artificial polymer commercially named as KOD. Because of its increased use, its market size is valued over USD 6.63 billion by 2025 [Collagen Market By Source (Bovine, Porcine, Poultry, Marine), Product (Gelatin, Hydrolyzed Collagen), Application (Food & Beverages, Healthcare, Cosmetics), By Region, And Segment Forecasts, 2014 - 2025. Grand View Research. http://www.grandviewresearch.com/industry-analysis/collagen-market. Published 2017.]. Nevertheless, there has been little effort on identifying which collagen types are the most suitable for cosmetic purposes, for which the present review will try to enlighten

  18. Proof of direct radiogenic destruction of collagen in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Acil, Y.; Springer, I.N.; Gassling, P.; Warnke, P.H.; Acmaz, S.; Soenmez, T.T.; Wiltfang, J. [Univ. Hospital Schleswig-Holstein, Kiel (Germany). Dept. of Oral and Maxillofacial Surgery; Niehoff, P.; Kimmig, B. [Univ. Hospital Schleswig-Holstein, Kiel (DE). Dept. of Radiotherapy (Radiooncology); Lefteris, V. [Univ. of Athens Medical School (Greece). Dept. of Oral and Maxillofacial Surgery

    2007-07-15

    Background: Fibroses of vessels and soft tissue are side effects of radiotherapy. The authors assumed that there was an immediate direct radiogenic damage of collagen of bone, periosteum and skin. Material and Methods: 15 porcine jaws samples (group 1) were exposed to a total dose of 60 Gy (cobalt-60, 2 Gy/day, five fractions/week). 15 jaws samples were stored accordingly (group 2, no irradiation, control). Collagen fragments of bone, periosteum and skin samples of groups 1 and 2 were isolated by ultrafiltration. Collagen types were characterized by SDS-PAGE measurement of the mature collagen cross-links hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) by high-performance liquid chromatog