Search results for "collage"
showing 10 items of 638 documents
Neural Crest-Derived Chondrocytes Isolation for Tissue Engineering in Regenerative Medicine
2020
Chondrocyte transplantation has been successfully tested and proposed as a clinical procedure aiming to repair articular cartilage defects. However, the isolation of chondrocytes and the optimization of the enzymatic digestion process, as well as their successful in vitro expansion, remain the main challenges in cartilage tissue engineering. In order to address these issues, we investigated the performance of recombinant collagenases in tissue dissociation assays with the aim of isolating chondrocytes from bovine nasal cartilage in order to establish the optimal enzyme blend to ensure the best outcomes of the overall procedure. We show, for the first time, that collagenase H activity alone …
Effects of streptozotocin-induced diabetes, physical training and their combination on collagen biosynthesis in rat skeletal muscle.
1995
The effects of streptozotocin-induced diabetes, physical training and their combination on the activities of prolyl 4-hydroxylase (PH) and galactosylhydroxylysyl glucosyl-transferase (GGT), both marker enzymes of collagen biosynthesis, and on the concentration of hydroxyproline (Hyp) were studied in vastus lateralis, rectus femoris and gastrocnemius muscles in rats. The experimental period was 12-16 weeks. Diabetes had an overall decreasing effect on specific PH activity in all muscles studied, whereas specific GGT activity remained at control level. Total PH and GGT activities decreased in all three muscles in the diabetic animals (P < 0.001). Training caused an increase in PH and GGT acti…
Novel α2β1 integrin inhibitors reveal that integrin binding to collagen under shear stress conditions does not require receptor preactivation.
2012
The interaction between α2β1 integrin (GPIa/IIa, VLA-2) and vascular collagen is one of the initiating events in thrombus formation. Here, we describe two structurally similar sulfonamide derivatives, BTT-3033 and BTT-3034, and show that, under static conditions, they have an almost identical effect on α2-expressing CHO cell adhesion to collagen I, but only BTT-3033 blocks platelet attachment under flow (90 dynes/cm(2)). Differential scanning fluorimetry showed that both molecules bind to the α2I domain of the recombinant α2 subunit. To further study integrin binding mechanism(s) of the two sulfonamides, we created an α2 Y285F mutant containing a substitution near the metal ion-dependent ad…
Incorporation and metabolism of dietary trans isomers of linolenic acid alter the fatty acid profile of rat tissues
2000
To study the influence on lipid metabolism and platelet aggregation of the fatty acid isomerization that occurs during heat treatment, weanling rats were fed for 8 wk a diet enriched with 5% isomerized (experimental group) or normal (control group) canola oil. Geometrical isomers of alpha-linolenic acid representing 0.2 g/100 g of the experimental diet were incorporated into liver, platelets, aorta and heart, at the expense of their cis homologue and of 18:2(n-6). The major isomer, 9c,12c,15t-18:3, was also metabolized to 5c,8c,11c,14c,17t-20:5 and to an unknown compound, found in liver, platelets and aorta, which has been identified tentatively as 7c, 10c,13c,16c,19t-22:5. The greater 20:4…
Influence of a collagen membrane and recombinant platelet-derived growth factor on vertical bone augmentation in implant-fixed deproteinized bovine b…
2012
Combinations of bone substitute block materials with membrane techniques as well as with growth factors are possible options to enhance the prognosis of vertical bone augmentation. Therefore, the aim of the pilot study was to compare the influence of a collagen membrane and a signal protein (rhPDGF-BB) on vertical bone augmentation with a stable fixed block material (deproteinized bovine bone [DBB]).In 12 rabbits, a DBB-block was implant-fixed on the tibia in a split-leg-design. Included were: DBB only (control), DBB + collagen membrane (test), DBB + rhPDGF-BB (test) and DBB + rhPDGF-BB + collagen membrane (test). 24 samples were examined after 3 (n = 12) and 6 weeks (n = 12). Calculated pa…
Pre‐clinical evaluation of the effect of a volume‐stable collagen matrix on periodontal regeneration in two‐wall intrabony defects
2021
Aim To histologically evaluate the effect of a new collagen matrix on periodontal regeneration. Materials and methods Two-wall intrabony defects were surgically created bilaterally distally to the maxillary first and third pre-molars in beagle dogs. The defects were randomly allocated to open flap debridement either with (test) or without (control) a volume-stable collagen matrix (VCMX). After 12 weeks, the dogs were euthanized, and the specimens histologically processed. Descriptive, histomorphometrical (vertical gain of periodontal tissues) and statistical analyses were then performed. Results Healing was uneventful in most cases. Residual VCMX was still present and showed integration int…
Microtomographic reconstruction of mandibular defects treated with xenografts and collagen-based membranes:a pre-clinical minipig model
2021
Background The goal of this study was to evaluate hard tissue response following guided bone regeneration using commercially available bovine bone grafts and collagen membranes; bilayer collagen membrane and porcine pericardium-based membrane, by means of a non-destructive three-dimensional (3D) computerized volumetric analysis following microtomography reconstruction. Material and Methods Bone regenerative properties of various bovine bone graft materials were evaluated in the Göttingen minipig model. Two standardized intraosseous defects (15mm x 8mm x 8mm) were created bilaterally of the mandible of eighteen animals (n=72 defects). Groups were nested within the same subject and randomly d…
miR-29b negatively regulates human osteoclastic cell differentiation and function: Implications for the treatment of multiple myeloma-related bone di…
2013
Skeletal homeostasis relies upon a fine tuning of osteoclast (OCLs)-mediated bone resorption and osteoblast (OBLs)-dependent bone formation. This balance is unsettled by multiple myeloma (MM) cells, which impair OBL function and stimulate OCLs to generate lytic lesions. Emerging experimental evidence is disclosing a key regulatory role of microRNAs (miRNAs) in the regulation of bone homeostasis suggesting the miRNA network as potential novel target for the treatment of MM-related bone disease. Here, we report that miR-29b expression decreases progressively during human OCL differentiation in vitro. We found that lentiviral transduction of miR-29b into OCLs, even in the presence of MM cells,…
Do More Highly Organized Collagen Fibrils Increase Bone Mechanical Strength in Loss of Mineral Density After One-Year Running Training?
1999
The aim of this study was to evaluate the effects of long-term running training on the structural properties of bone. Ten beagle dogs ran according to a strenuous progressive program (up to 40 km/day) for 1 year. At the end of the training program, there was a significant reduction in bone mineral density (up to 9.7%) in the vertebrae of the runner dogs as compared with 10 sedentary control dogs. Polarized light microscopy of the vertebral trabecular bone, however, displayed proportionally higher retardation values of the collagen network of the runner dogs than of the sedentary dogs, suggesting a reorganization in a more parallel manner in the collagen fibrils. The concentration and cross-…
Serum and urine markers of type I collagen metabolism in elderly women with high and low bone mineral density.
1996
The serum markers of bone formation (carboxy-terminal propeptide of type I collagen, PICP) and resorption (pyridinoline cross-links containing telopeptide of type I collagen, ICTP), as well as urinary resorption markers, pyridinoline (Pyr) and deoxypyridinoline (Dpyr), were studied in 78-year-old women with high (n = 18) and low (n = 17) bone mineral density (BMD) measured from the calcaneus and tibia. The low-BMD group had higher values for PICP (P = 0 center dot 025), Pyr (P = 0 center dot 001) and Dpyr (P < 0 center dot 001) than the high-BMD group. No inverse relationship between these markers and BMD was, however, observed within the study groups. ICTP, Pyr and Dpyr correlated with eac…