Search results for "Collagen"

A new method to value efficiency of enzyme blends for pancreatic tissue digestion.

2010

Islet transplantation, since the 90’s, has been resulting to be one of the best successful example of human cell therapy. Nevertheless, islet isolation procedure is not completely standardized; in fact, more than fifty percent of islets procedures don’t arrive to their transplantation. This is due both to the variability of donor’s pancreas and to an unpredictable enzymatic blend efficiency. Enzymes used in pancreas digestion are extracted from Clostridium histolyticum bacteria and digest several substrates. In particular they have strong collagenolytic activity compared to vertebrate collagenases. However, several impediments persist in human islet isolation success probably due to the var…

Influence of Oral Contraceptive Use on Adaptations to Resistance Training

2019

Introduction: The majority of young women use oral contraceptives (OCs). Use of OCs has been associated with lower myofibrillar protein and tendon collagen synthesis rates, but it is unknown whether OCs will limit the adaptive response of myotendinous tissue to resistance training. Design and Methods: Fourteen healthy untrained young regular OC users (24 +/- 1 years, fat% 32 +/- 1, 35 +/- 2 ml.min(-1).kg(-1)) and 14 NOC users (non-OC, controls) (24 +/- 1 years, fat% 32 +/- 2, 34 +/- 2 ml.min(-1).kg(-1)) performed a 10-week supervised lower extremity progressive resistance training program. Before and after the intervention biopsies from the vastus lateralis muscle and the patellar tendon we…

Integrin-mediated Cell Adhesion to Type I Collagen Fibrils

2004

In the integrin family, the collagen receptors form a structurally and functionally distinct subgroup. Two members of this subgroup, α1β1 and α2β1 integrins, are known to bind to monomeric form of type I collagen. However, in tissues type I collagen monomers are organized into large fibrils immediately after they are released from cells. Here, we studied collagen fibril recognition by integrins. By an immunoelectron microscopy method we showed that integrin α2I domain is able to bind to classical D-banded type I collagen fibrils. However, according to the solid phase binding assay, the collagen fibril formation appeared to reduce integrin α1I and α2I domain avidity to collagen and to lower …

Reconstruction of human subsistence and husbandry strategies from the Iberian Early Neolithic: A stable isotope approach

2018

Objectives The Early Neolithic involved an important social and economic shift that can be tested not only with the material culture, but also through biomolecular approaches. The Iberian Peninsula presents few Early Neolithic sites where fauna and humans can be analyzed together from an isotopic perspective. Here we present an isotopic study on the site of Cueva de Chaves as an example for understanding the dietary and economical changes that took place during Early Neolithic in Iberia. Material and methods Here we apply carbon and nitrogen stable isotope analysis to bone collagen from 4 humans and 64 faunal samples from 14 different species. The large dataset belongs to the same unique ch…

In vitro testing the potential of a novel chimeric igg variant for inhibiting collagen fibrils formation in recurrent hereditary gingival fibromatosi…

2014

Gingival fibromatosis is a progressive enlargement of the gingiva. It may hinder oral cavity hygiene and result in underlying bone loss. The long-term benefits of surgery cannot be predicted. On the other hand, alternative, efficient and non-invasive methods are not available at present. The aim of this study was to test the inhibitory effects of a chimeric IgG variant on collagen fibril formation in the cell culture of gingival fibroblasts taken from a patient with hereditary gingival fibromatosis with a high propensity for recurrence. Gingival biopsies were collected from the mandibular gingiva and used for histological evaluation as well as to establish a fibroblast culture. A histologic…

Phosphorylation of the Goodpasture antigen by type A protein kinases.

1995

Collagen IV is the major component of basement membranes. The human alpha 3 chain of collagen IV contains an antigenic domain called the Goodpasture antigen that is the target for the circulating immunopathogenic antibodies present in patients with Goodpasture syndrome. Characteristically, the gene region encoding the Goodpasture antigen generates multiple alternative products that retain the antigen amino-terminal region with a five-residue motif (KRGDS). The serine therein appears to be the major in vitro cAMP-dependent protein kinase phosphorylation site in the isolated antigen and can be phosphorylated in vitro by two protein kinases of approximately 50 and 41 kDa associated with human …

Molybdenum blue: Binding to collagen fibres and microcrystal formation

2005

Collagen fibres have been shown by transmission electron microscopy to progressively bind the polyoxomolybdate ring-complex, termed molybdenum blue. Nucleation of cuboidal molybdenum blue microcrystals occurs on the surface of the collagen fibres, leading eventually to extensive coating of the fibres with microcrystals.

Silver-loaded nanoparticles affect ex-vivo mechanical behavior and mineralization of dentin

2019

Background: The aim was to evaluate the effect of silver loaded nanoparticles (NPs) application on the triboscopic, crystallographic and viscoelastic properties of demineralized dentin. Polymethylmetacrylate-based NPs and Ag loaded NPs were applied on demineralized dentin. Material and Methods: Treated and untreated surfaces were probed by a nanoindenter to test viscoelasticity, and by atomic force microscopy to test nanoroughness and collagen fibril diameter. X-ray diffraction and transmission electron microscopy through selected area diffraction and bright-field imaging were also used. Results: Dentin treated with Ag-NPs attained the lowest complex modulus, and the highest tan delta value…

Interactions of α2β1 integrin and its ligands, type I collagen and echovirus 1

2015

Tissue Dissociation and Primary Cells Isolation Using Recombinant Collagenases Class I and II

2014

Collagenases class I (Col G) and class II (Col H) currently available for tissue dissociation are produced from Clostridium histolyticum (human pathogen) strains. In the processes of extraction of the cells from the tissue, combined activity of both classes of enzymes is required. CI and CII are complementary in degrading collagen. ABIEL recently produced the collagenase class I and II using the recombinant DNA technologies (PCT WO 2011/073925 A9). The enzymes were produced in E. coli and purified by affinity chromatography. The method of production adopted allows absolute control of the final composition of these enzymes, as well as their stability, purity, activity, absence of toxicity an…