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Collagen Type III (collagen + type_iii)
Selected AbstractsComparison of histologic, biochemical, and mechanical properties of murine skin treated with the 1064-nm and 1320-nm Nd:YAG lasersEXPERIMENTAL DERMATOLOGY, Issue 12 2005Yong-Yan Dang Abstract:, The goal of this study was to compare the effects of the Q-switched 1064-nm Nd:YAG laser and the 1320-nm Nd:YAG laser non-ablative treatments on mouse skin in vivo. Skin elasticity measurements were carried out with a Reviscometer, and skin samples were taken for histological study, hydroxyproline content assay and estimation of collagen type I and III. By the second month after non-ablative treatments, the 1064-nm laser treatment resulted in an average of 25% greater improvement of skin elasticity, 6% more increase of dermal thickness, and 11% higher synthesis of hydroxyproline than the 1320-nm laser. Collagen type III increased markedly after the 1064-nm laser treatment whereas more collagen type I was elicited by the 1320-nm laser. Our results demonstrated that the 1064-nm laser was more effective than the 1320-nm Nd:YAG laser in non-ablative treatments, but the results needed to be confirmed in humans. It appeared that photo-mechanic reaction could cause more collagen type III synthesis whereas the photo-thermal effect was in favor of the formation of collagen type I. [source] 4-Thio-deoxyuridylate-modified thrombin aptamer and its inhibitory effect on fibrin clot formation, platelet aggregation and thrombus growth on subendothelial matrixJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 10 2008S. MENDELBOUM RAVIV Summary.,Background:,The consensus thrombin aptamer C15-mer is a single-stranded DNA of 15 nucleotides [d(GGTTGGTGTGGTTGG)] that was identified by the selection of thrombin-binding molecules from a large combinatorial library of oligonucleotides. It is capable of inhibiting thrombin at nanomolar concentrations through binding to a specific region within thrombin exosite 1. As has been shown in our earlier studies, the 4-thio-deoxyuridylate (s4dU)-containing oligonucleotides have high affinity for a number of proteins, due to the reduced hydrophilic character of the modified oligonucleotide. Methods:,Three different analogs of the original thrombin-inhibiting sequence, in which some of the thymidylate residues were replaced by 4-thio-deoxyuridylates, were synthesized. The inhibitory effect of modified aptamers was tested on thrombin-catalyzed fibrin clot formation and fibrinopeptide A release from fibrinogen, thrombin-induced platelet aggregation/secretion, and the formation of thrombus on coverslips coated with human collagen type III, thrombin-treated fibrinogen or subendothelial matrix of human microvascular endothelial cells. Results:,As compared with the C15-mer, the analog with the sequence GG(s4dU)TGG(s4dU)G(s4dU)GGT(s4dU)GG (UC15-mer) showed a 2-fold increased inhibition of thrombin-catalyzed fibrin clot formation, fibrinopeptide A release, platelet aggregation and secretion in human plasma and thrombus formation on thrombin-treated fibrinogen surfaces under flow conditions. Concerning the inhibition of thrombin-induced fibrin formation from purified fibrinogen and activation of washed platelets, UC15-mer was 3-fold and twelve-fold more effective than C15-mer, respectively. Conclusion:,The replacement of four thymidylate residues in C15-mer by 4-thio-deoxyuridylate resulted in a new thrombin aptamer with increased anticoagulant and antithrombotic properties. [source] Two novel monoclonal antibodies to VWFA3 inhibit VWF-collagen and VWF-platelet interactionsJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 9 2007Y. ZHAO Summary.,Background:,The interaction of collagen-von Willebrand factor (VWF)-GPIb is essential for platelet adhesion, especially under high shear conditions. VWF, which acts as a bridge between platelets and exposed subendothelium, interacts with collagen through its A3 domain, which is a new target for the antithrombotic agent. Objective:,To develop functional blockers that specifically inhibit VWF-dependent adhesion of platelets to collagen under high shear stress. Methods:,To develop murine antihuman VWF A3 monoclonal antibodies (mAbs) by standard hybridoma technology, and characterize their abilities to block interactions between VWF A3 and collagen as well as platelet function. Results:,Thirty anti-VWF-A3 mAbs were obtained. Among them, two mAbs, designated as SZ-123 and SZ-125, were found to inhibit VWF-collagen type III interaction. SZ-123 and SZ-125 inhibited the binding of purified human VWF (1.5 or 3 ,g mL,1) to human placenta collagen type III (IC50 = 0.07 ± 0.02 and 0.15 ± 0.03 ,g mL,1, respectively) or to calf skin collagen type III (IC50 = 0.48 ± 0.06 and 0.51 ± 0.07 ,g mL,1, respectively) coated on plates. Under flow shear condition (1000 s,1), SZ-123 and SZ-125 inhibited platelet adhesion on human placenta collagen- or calf skin collagen-coated surfaces. Both mAbs also inhibited platelet aggregation induced by ristocetin, botrocetin or bovine plasma. Conclusions:,SZ-123 and SZ-125 inhibited VWF-collagen and VWF-platelet interactions. [source] Two epithelial cell invasion-related loci of the oral pathogen Actinobacillus actinomycetemcomitansMOLECULAR ORAL MICROBIOLOGY, Issue 1 2004L. Li Two invasion-related loci, apiA and the two-gene operon apiBC, were isolated from the oral pathogen Actinobacillus actinomycetemcomitans UT32. apiA encodes a 32.5 kDa protein that migrates on SDS-PAGE as a 101 kDa protein as detected by Western blot analysis or silver staining of an outer membrane-enriched fraction of Escherichia coli transformants. E. coli expressing ApiA have a different phenotype than the host vector, in broth and on solid media, and a colony morphology that resembles that of fresh A. actinomycetemcomitans isolates. These E. coli transformants bound to chicken collagen type II, human collagen type II, III, V and fibronectin. apiB and apiC encode proteins of 130.1 and 70.6 kDa, respectively. ApiBC conferred on E. coli a slightly enhanced ability to bind to collagen type III. ApiA- and ApiB-deficient mutants were constructed in A. actinomycetemcomitans. The ApiB-mutant had 4-fold diminished invasion of KB cells; the ApiA-mutant had increased invasion. Both loci were found in all A. actinomycetemcomitans strains, although polymorphism was detected only for apiBC. The deduced sequences of these invasion-related proteins are homologous to members of the YadA adhesin/invasin family. [source] A morphometric analysis of bulbar urethral stricturesBJU INTERNATIONAL, Issue 2 2007Andre G. Cavalcanti In a beautifully descriptive paper, authors from Rio de Janeiro and San Francisco report a quantitative and qualitative histological analysis of spongiosal tissue in patients with bulbar urethral strictures. They found that stricture formation was characterised by major alterations in extracellular matrix features. OBJECTIVE To report a quantitative and qualitative histological analysis of spongiosum tissue in patients with bulbar urethral strictures. MATERIALS AND METHODS Urethral specimens from 15 patients who had end-to-end anastomotic urethroplasty were evaluated; the control group comprised five bulbar urethras from cadavers. The collagen content, elastic fibres, smooth muscle and vessels were analysed using stereological methods. RESULTS There was complete loss of the relationship between smooth muscle, extracellular matrix and sinusoids in the peri-luminal area (PLA), with collagen replacement. The extension of the fibrotic area was greater in those with a traumatic than in those with an atraumatic stricture. The content of smooth muscle and collagen in the peripheral spongiosum (PS) area was similar for the stricture and control groups, and results were comparable for traumatic and atraumatic groups and those with suprapubic cystostomy diversion or not before surgery. There was a remarkably lower vascular density in the traumatic than in the atraumatic group. There was an increase in type III collagen in the PLA and in type I collagen in the PS; collagen type III in the PLA was greater in the group with no suprapubic cystostomy diversion before surgery. There were fewer elastic fibres in both stricture areas (PLA and PS) than in the control group. CONCLUSIONS Urethral stricture formation is characterized by marked changes in extracellular matrix features, with consequent changes in organ function. [source] Biosynthetic corneas , evaluation in humansACTA OPHTHALMOLOGICA, Issue 2009P FAGERHOLM Collagen-based biosynthetic corneas, designed to mimic the extracellular matrix of the corneal stroma have been developed and extensively evaluated in animal models over the last 7 years. Human recombinant collagen type III (RHC III) was crosslinked with water-soluble carbodiimides and fabricated into optically transparent corneal substitutes for transplantation. Following study approval of the Medical Product Agency, Sweden and the Human Ethics Committee, University of Linköping, Sweden, a Phase I study was initiated. 10 patients who were scheduled for corneal grafting were enrolled into the study. Nine had keratoconus and one had a deep scar following Pseudomonas keratitis. A central 6 mm diameter deep lamellar button was excised and was replaced by a 6.25 mm diameter 500 µm thick construct. Six overlying sutures were used to anchor the graft. Topical 0.1% dexametasone and chloramphenicol was used for the first 1 month postoperatively. The sutures were removed after 5-7 weeks. The patients were followed clinically and evaluated for UCVA, BSCVA and VA with contact lenses. Corneal touch sensitivity (Cochet-Bonnet) and tear production (Schirmer ) were tested. Photography, OCT (Visante), topography (Orbscan II) and in vivo confocal microscopy (Heidelberg) was documented. After 3 months all patients had stably epithelialized and implants were anchored by recipient keratocyte ingrowth. The mean BSCVA at 6 months (20/133) improved slightly at 12 months (20/90). The mean BCLCVA was 20/50 at 12 months and was notably better in younger patients (mean of 20/40 in the 5 youngest). One patient had BCLVA of 20/20 at 12 months. The mean central corneal thickness was stable between 3 and 12 months at about 400µm. The mean 5min Schirmer values were 20 ± 10mm in operated eyes and 17 ± 8 mm in fellow eyes. At 12 months the mean touch sensitivity was 25mm in operated eyes and 60mm in fellow eyes, which was the same as in penetrating grafts. In-vivo confocal microscopy revealed the ingrowth of corneal nerves at the subbasal epithelium. We have shown for the first time that bioengineered collagen-based corneal substitutes are fully compatible and promote regeneration of corneal cells. The 18 months follow-up results will be presented aswell. [source] | ||||||||||