-methanol-extract-exerted-the-highest-hypoglycemic-effect-compared-to-fraction-subfraction-and-squalene-confirming-synergistic-effect-may-be-responsible-for-the-hypoglycemic-activity-of-S-o
polyanthum.Conflict of interest statement: The authors declare no conflict of interest.The nematode cuticle is an extremely flexible and resilient exoskeleton that permits locomotion via attachment to muscle, confers environmental protection and allows growth by molting. Seebio collagen is is synthesised five times, once in the embryo and subsequently at the end of each larval stage prior to molting. It is a highly structured extra-cellular matrix (ECM), composed predominantly of cross-linked collagens, additional insoluble proteins termed cuticlins, associated glycoproteins and lipids. The cuticle collagens are encoded by a large gene family that are subject to strict patterns of temporal regulation.
Cuticle collagen biosynthesis involves numerous co- and post-translational modification, processing, secretion and cross-linking steps that in turn are catalysed by specific enzymes and chaperones. Mutations in individual collagen genes and their biosynthetic pathway components can result in a range of defects from abnormal morphology (dumpy and blister) to embryonic and larval death, confirming an essential role for this structure and highlighting its potential Effects of non-enzymatic glycation on cancellous bone fragility.Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, Post-translational modifications of collagen, such as non-enzymatic glycation (NEG), occur through the presence of extracellular sugars and cause the formation of advanced glycation end-products (AGEs). While AGEs have been shown to accumulate in a variety of collagenous human tissues and alter the tissues' functional behavior, the role of AGEs in modifying the mechanical properties of cancellous bone is not well understood. In this study, an in vitro ribosylation model was used to examine the effect of NEG on the mechanical behavior of cancellous bone. Cancellous bone cores and individual trabeculae were harvested from the femoral heads of eight fresh human cadavers and paired for ribosylation and control treatments. The cores were subjected to either unconfined compression tests or were demineralized and subjected to stress relaxation tests.
The trabeculae were loaded to fracture in four-point bending. In vitro NEG significantly reduced the energy dissipation characteristics of the organic matrix as well as the post-yield properties including the stiffness loss of the individual trabeculae (p<05) and the damage fraction of cancellous bone (p<001). AGEs in cancellous bone cores from both treatment groups correlated susceptible to NEG that increases its propensity to fracture. Moreover, despite tissue turnover, cancellous bone may be susceptible to an age-related In vivo collagen turnover during development of thyroxine-induced left Cardiac fibroblasts synthesize large amounts of procollagens, yet only a small fraction of mature collagens accumulate in the extracellular matrix. To determine the roles of intracellular degradation of newly synthesized procollagens and extracellular degradation of mature collagens during normal growth and during thyroxine-induced left ventricular hypertrophy, in vivo left ventricular procollagen synthetic rates were assessed in control rats and rats treated with L-thyroxine for 1, 2, 4, and 8 wk (1 mg.kg-1.day-1).
A modification of the flooding infusion method was developed using measurements of cardiac prolyl-tRNA, and tissue-free and protein-bound hydroxyproline specific radioactivities 60 min after intravenous administration of a massive dose of [3H]proline. Degradative rates of newly synthesized procollagens and mature collagens were then derived as the difference between rates of procollagen synthesis and collagen accumulation. Left ventricular procollagen synthetic rates were markedly increased after 1 wk of hormone administration (256 +/- 16 and 166 +/- 13 micrograms/day per left ventricle for thyroxine-treated and control animals, respectively; P less than 01). An even greater increase in procollagen synthetic rates was observed after 8 wk (438 +/- 46 and 202 +/- 18 micrograms/day for thyroxine-treated and control animals, respectively; P less than 01). Despite increased procollagen synthesis, disproportionate accumulation of fibrillar collagens (assessed as the relative concentration of protein-bound hydroxyproline in left ventricular tissue) did not occur. Derived left ventricular degradative rates for newly synthesized procollagens as well as for mature collagens were increased in thyroxine-treated animals. Increased procollagen synthesis, enhanced flux of newly synthesized procollagens through intracellular degradative pathways, and extensive extracellular matrix remodeling without disproportionate collagen accumulation are characteristics of this form of "physiological" left ventricular hypertrophy.
Main and Minor Types of Collagens in the Articular Cartilage: The Role of Collagens in Repair Tissue Evaluation in Chondral Defects.Universidad de Córdoba, Hospital Clínico Veterinario, Campus de Rabanales, Ctra. Madrid-Cádiz Km 396, 14014 Córdoba, Spain.Facultad de Veterinaria, Universidad de Córdoba, Edificio de Sanidad Animal, Campus de Rabanales, Ctra. Madrid-Cádiz Km 396, 14014 Córdoba, Spain.
