Search results for "Collagen"
showing 10 items of 620 documents
Fracture Mechanics of Collagen Fibrils: Influence of Natural Cross-Links
2013
AbstractTendons 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 fibrils is limited. The presence of covalent enzymatic cross-links between collagen molecules is an important factor that has been shown to influence mechanical behavior of the tendons. To improve our understanding of how molecular bonds translate into tendon mechanics, we used an atomic force microscopy technique to measure the mechanical behavior of individual collagen fibrils loaded to failu…
Digital image analysis of liver collagen predicts clinical outcome of recurrent hepatitis C virus 1 year after liver transplantation.
2011
Clinical outcomes of recurrent hepatitis C virus after liver transplantation are difficult to predict. We evaluated collagen proportionate area (CPA), a quantitative histological index, at 1 year with respect to the first episode of clinical decompensation. Patients with biopsies at 1 year after liver transplantation were evaluated by Ishak stage/grade, and biopsy samples stained with Sirius red for digital image analysis were evaluated for CPA. Cox regression was used to evaluate variables associated with first appearance of clinical decompensation. Receiver operating characteristic (ROC) curves were also used. A total of 135 patients with median follow-up of 76 months were evaluated. At 1…
Combined evaluation of resting IGF-I, N-terminal propeptide of type III procollagen (PIIINP) and C-terminal cross-linked telopeptide of type I collag…
2004
To verify whether combined measurements of GH-dependent parameters might be useful in detecting exogenous recombinant GH (rGH) administration in male athletes from different disciplines.Sixty-six athletes (control group) were sampled for the evaluation of resting IGF-I, N-terminal propeptide of type III procollagen (PIIINP) and telopeptide type I collagen (ICTP). Cut-off values (mean + 2 SD) for IGF-I, PIIINP and ICTP were calculated and arbitrary scores (1.5, 2.0) were assigned to abnormal parameters. By using the sum of individual parameter scores, positive (or = 3) or negative (3) scores were obtained. In addition, a subgroup of six athletes was treated for 3 weeks with rGH (0.09 IU/kg b…
Efficacy of a Spray Compound Containing a Pool of Collagen Precursor Synthetic Amino Acids (L-Proline, L-Leucine, L-Lysine and Glycine) Combined with…
2010
Oral mucositis (OM) is a very frequent and potentially severe complication experienced by patients receiving chemotherapy and/or radiotherapy, which often leads to significant morbidity and mortality, and decreased quality of life, and is very costly. Despite its severity and prevalence, there is no standard recognised management today. The aim of this open clinical trial is to evaluate the efficacy and compliance of a new spray compound containing sodium hyaluronate (SH) and a pool of collagen precursor amino acids (AAs) combined with sodium hyaluronate (SH) to manage radio/chemotherapy-induced OM. Twenty-seven consecutive patients with OM were treated according to the manufacturer's inst…
Corticosteroid injections, eccentric decline squat training and heavy slow resistance training in patellar tendinopathy.
2009
Udgivelsesdato: Sep-28 A randomized-controlled single-blind trial was conducted to investigate the clinical, structural and functional effects of peritendinous corticosteroid injections (CORT), eccentric decline squat training (ECC) and heavy slow resistance training (HSR) in patellar tendinopathy. Thirty-nine male patients were randomized to CORT, ECC or HSR for 12 weeks. We assessed function and symptoms (VISA-p questionnaire), tendon pain during activity (VAS), treatment satisfaction, tendon swelling, tendon vascularization, tendon mechanical properties and collagen crosslink properties. Assessments were made at 0 weeks, 12 weeks and at follow-up (half-year). All groups improved in VISA-…
Use of a new cross-linked collagen membrane for the treatment of dehiscence-type defects at titanium implants: a prospective, randomized-controlled d…
2009
OBJECTIVES The aim of the present randomized-controlled double-blinded clinical multicenter study was to assess the use of either a new cross-linked (VN) or a native collagen membrane (BG) for the treatment of dehiscence-type defects at titanium implants. MATERIAL AND METHODS A total of n=54 patients were recruited in four German university clinics. According to a parallel-groups design, dehiscence-type defects at titanium implants were filled with a natural bone mineral and randomly assigned to either VN or BG. Submerged sites were allowed to heal for 4 months. Primary (e.g., changes in defect length - DeltaDL, quality of newly formed tissue [0-4] - TQ) and secondary parameters (e.g., memb…
Bone Resorption in Kidney Transplant Recipients
2009
Early diagnosis of persistent hyperparathyroidism (HP) following kidney transplantation may prevent worsening of osteodystrophy and potential damage to the graft. We evaluated the utility of collagen pyridinoline (PYD) and deoxypyridinoline (DPD) urinary cross-links beyond the common HP markers to evaluate 70 selected stable recipients between 1997 and 2006 who were divided into 2 group depending on the immunosuppressive protocol. All patients showed elevated levels of urinary cross-links even though calcemia and phosphoremia values were normal. Their mean creatinine level was slightly increased. Data were assessed as mean values +/- SD. All variables underwent a correlation matrix analysis…
Serum levels of type III procollagen peptide in diabetes mellitus.
1989
Serum levels of type III procollagen peptide (P-III-P) were investigated in 19 patients with type 1 (insulin-dependent) and in 48 (25 orally treated, 23 insulinized) patients with type 2 (non insulin-dependent) diabetes mellitus. Among patients with type 2 diabetes, 16 orally treated and 14 insulin-treated subjects had macrovascular complications. P-III-P levels were not correlated with the duration of diabetes and with glucose control, nor were there any significant sex and age differences in the levels. P-III-P values were significantly higher in the sera of insulin-treated non insulin-dependent diabetic patients with macroangiopathy. These high values (18.5 +/- 10.8 ng/ml) were in contra…
Age-related dermal collagen changes during development, maturation and ageing - a morphometric and comparative study.
2014
The tissue organisation of dermal collagen is gaining importance as a contributing factor both in development and ageing, as well as in skin maturation processes. In this work we aim to study different representative parameters of this structural organisation in 45 human skin samples of assorted ages, by means of image analysis. The variation of these parameters on the basis of age was assessed using several regression models (linear, quadratic and cubic). The area occupied by collagen was significantly reduced as a function of age in the papillary dermis (R(2) = 0.437, P < 0.0001), as well as the thickness of the collagen bundles (R(2) = 0.461, P < 0.0001), following statistical models of …
Effect of dual blockade of renin–angiotensin system on TGFβ1 and left ventricular structure and function in hypertensive patients
2007
The effects of 24 weeks losartan and ramipril treatment, both alone and in combination, on left ventricular mass (LVM), circulating transforming growth factor beta1 (TGFbeta1), procollagen type I (PIP) and III (PIIIP), have been evaluated in hypertensive (HT) patients. A total of 57 HT with stage 1 and 2 essential hypertension were included. After 4 weeks run in, a randomized double-blind, three arms, double dummy, independent trial was used. All HT patients were randomly allocated to three treatment arms consisting of losartan (50 mg/daily), ramipril (5 mg/ daily) and combined (losartan 50 mg/daily + ramipril 5 mg/daily) for 24 weeks. TGFbeta1, PIP and PIIIP, LVM, LVM/h(2.7) and other echo…