Nutidens formidling af Danmarks historie?

Articular cartilage covering the bone ends at the joint shows different chemical composition in different regions, depending on the mechanical and biological properties of that region. Several studies have shown a relationship between the chemical composition of the cartilage and biomechanical forces. In the present study we analysed five different knee joints divided into the following regions: F1 - medial and lateral border of the patellar surface, F2 - patellar surface of the femur, F3 - medial and lateral condyles, P - articular surface of the patella and T - medial and lateral condyle of the tibia. The main glycosaminoglycan (GAG) present in these regions was chondroitin sulfate. Analysis of total GAG after digestion of the tissue with papain showed that in F2 and F3 there was a larger quantity of GAG/mg tissue, probably due to the dynamic character of the biomechanical forces in these regions. No significant differences were found for the extract and D1 fractions of the different regions. Analysis of the D4 fraction showed that the protein content was higher in the F3 and P regions than in their opposite T and F2 regions. The differences among the five regions may be a result of the non-uniform presence of biomechanical forces supported by these regions. It is important to consider that the intensity and direction of stress in different parts of a tissue may influence the composition of the extracellular matrix.179543343

Morphological modifications of knee articular cartilage in bullfrogs (Lithobates catesbeianus) (Anura: Ranidae) during postmetamorphic maturation

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)The organization of knee articular cartilage of the bullfrog (Lithobates catesbeianus) differs in relation to morphofunctional adaptation in many aspects from similar structures in mammals. Thus, we investigated the structural organization and distribution of the extracellular matrix components in three articular cartilage regions in the distal epiphysis of the femur and proximal epiphysis of the tibia in male bullfrogs at 7, 540 and 1,080 days after metamorphosis. Cartilage thickness and cell density decreased in all regions with age. The basophilia differed among cartilage sites during aging. Calcium deposits were detected in growth cartilage of the femur and tibia in older animals. Immunohistochemical staining for chondroitin-6-sulfate was positive in the pericellular and territorial matrix in all samples. Positive immunostaining for type I collagen was observed in the superficial layer at all ages and in ossification centers of older animals. Reactivity to type II collagen was intense and was found throughout the stroma at all ages. Ultrastructural analysis of the epiphyseal region, in young animals, showed that the cytoplasm of chondrocytes was rich in rough endoplasmic reticulum, Golgi complex and mitochondria. In old animals, were observed a reduction in the size and number of mitochondria, disintegration of rough endoplasmic reticulum, and vacuolization of the Golgi complex. The bullfrog articular cartilage presented structural and organizational changes during aging which may contribute to the functional cartilage deterioration in old animals.1332245256Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundacao Herminio OmettoCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

The effect of age on the structure and composition of rat tendon fibrocartilage

Biochemical and morphological aspects of fibrocartilages of calcaneal and deep digital flexor tendons in rats aged 30, 180 and 730 days were analyzed. In both tendons a stronger staining with Alcian blue, indicating the presence of proteoglycans, was detected in rats of 30 and 180 days. In animals 730 days old, it was restricted to the pericellular area. Ultrastructural analysis showed a more prominent pericellular matrix in calcaneal tendon compared to the deep digital flexor tendon. The biochemical analysis showed higher levels of proteins and glycosaminoglycans in the calcaneal tendon of 30-day-old rats compared to older rats. In the deep digital flexor tendon, no significant differences were observed between ages. The small proteoglycan, fibromodulin, was detected in both tendons of all ages, but in young rats it appeared to be running as a 210 kDa component, probably due to the association with collagen chains or self-association. (c) 2006 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.31657057

Evaluation of the effects of electrical stimulation on cartilage repair in adult male rats

This study describes the organization of mature hyaline xiphoid cartilage during repair in animals submitted to electrical current stimulation. Twenty male Wistar rats, 90 days old, were divided into a control group (CG) and a treated group (TG). A cylindrical full-thickness cartilage defects were created with a 3-mm punch in anesthetized animals. After 24 h, TG received daily applications of a continuous electrical current (1 Hz/20 mu A) for 5 min. The animals were sacrificed after 7, 21 and 35 days for structural analysis. In CG, the repair tissue presented fibrous characteristics, with fibroblastic cells being infiltrated and permeated by blood vessels. Basophilic foci of cartilage tissue were observed on day 35. In TG, the repair tissue also presented fibrous characteristics, but a larger number of thick collagen fibers were seen on day 21. A large number of cartilaginous nests were observed on day 35. Cell numbers were significantly higher in TG. Calcification points were detected in TG on day 35. There was no difference in elastic fibers between groups. Ultrastructural analysis revealed the presence of chondrocyte-like cells in CG at all time points, but only on days 21 and 35 in TG. The amount of cuprolinic blue-stained proteoglycans was higher in TG on day 35. Microcurrent stimulation accelerates the repair process in non-articular hyaline cartilage. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.45427528

Anti-hemorrhagic effect of hydro-alcoholic extract of the leaves of Mikania glomerata in lesions induced by Bothrops jararaca venom in rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)PURPOSE: To investigate the effects of hydroalcoholic leaf extract of Mikania glomerata Spreng (Asteraceae) on the activity of Bothrops jararaca snake venom in Wistar rats. METHODS: Fifty four rats Wistar were divided into six groups of nine animals in each: control treated with saline; control treated with B. jararaca venom; control treated with M. glomerata extract; B. jararaca venom incubated with M. glomerata extract at proportions of 1:1, 1:2, and 1:4. RESULTS: Histopathological and morphometric analysis showed that intradermal administration of snake venom incubated with the hydroalcoholic extract at proportions of 1:1, 1:2 and 1:4 promoted a significant reduction in the number of inflammatory cells and a marked decrease in edema after the third hour. There was also a significant reduction in the intensity of the hemorrhagic halo in animals receiving the snake venom incubated with the extract, with the observation of a progressive and parallel inhibition with increasing proportion of M. glomerata. CONCLUSION: The Mikania glomerata hydroalcoholic extract exerted effective anti-inflammatory and antihemorrhagic activity against the effects induced by Bothrops jararaca snake venom.2913037Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq [108113/2010-8

Electrospun Membranes of Poly(Lactic Acid) (PLA) Used as Scaffold in Drug Delivery of Extract of Sedum Dendroideum

Biomaterials nanofibrous electrospun with biodegradable polymers have the advantage of the similarity to natural extracellular matrices, showing promising as scaffolds for application in tissue engineering. Sedum dendroideum is a phytotherapic drug that stands out for its healing properties and anti-inflammatory. This study presents the efficacy of PLA electrospun membranes used as support S. dendroideum extract releasing on excisional skin lesions of Wistar rats. The PLA porous membranes, which are nonwoven fibrous mats, were obtained by electrospinning using a conventional apparatus with a flat collector. The animals were randomly divided into nine groups: control (C), animals treated with electrospun membranes of PLA (M), animals treated with extract of S. dendroideum dissolved in saline (F), animals treated with membranes of PLA with 10% S. dendroideum (MF10), animals treated with membranes of PLA with 25% S. dendroideum (MF25). Tissue samples were taken after 2, 6 and 10 days after surgery and were subjected to structural analysis and morphology. The experimental observations showed the application of the phytotherapic incorporated in the membrane promoted a significant response regarding the number of inflammatory cells, percentage of mature collagen fibers and epithelium birrefringent in thickness excisional skin lesions in Wistar rats. It was also demonstrated that the application of the PLA membranes without the extract promoted similar responses tissues.1374694470