Articular cartilage homeostasis after anterior cruciate ligament reconstruction

PubMed ID: 9604193Several factors may be responsible for osteoarthritis after anterior cruciate ligament (ACL) reconstruction. The detrimental effect of the surgical technique may explain part of the progression of the pathologic process. In this study, the effect of ACL reconstruction on articular cartilage was investigated by measuring proteoglycan fragments (PF) in synovial fluid collected from patients who had undergone this operation. Synovial samples were obtained from 44 patients with chronic ACL deficiency aged 26 ± 7 years preoperatively, and from some of them, samples were collected for monitoring at 1 month (n = 22), 3 months (n = 17), 6 months (n = 18) and 12s month (n = 18). Synovial fluid taken from 12 contralateral asymptomatic knees of 12 patients (not necessarily opposite knees of ACL-deficient cases) served as controls. Preoperative values were significantly larger than controls (P < 0.05). PF level reached its maximum value in the 1st month (P < 0.05) and then gradually decreased. It was significantly lower than preoperative values at 6 and 12 months but still greater than controls (P < 0.05). It seems that surgical trauma affects cartilage metabolism for the first 3 months postoperatively. Although reconstruction of the ACL contributes to articular cartilage homeostasis, a complete return to normal values cannot be achieved in 1st postoperative year at least in knees with chronic ACL deficiency. Long-term monitoring is needed to see whether these findings are early signs of osteoarthritis. Further studies may more clearly demonstrate the effect of the surgical procedure on knees with acute and subacute ACL deficiency

Chronic synovitis caused by a date palm thorn: an unusual clinical picture

PubMed ID: 11830822Synovitis related to plant thorns is a rare pathology. As in this case, thorn prick injury, which is particularly caused by thin palm thorns, is frequently missed in clinical history. Clinical presentation of cases may simulate juvenile rheumatoid arthritis with monoarticular involvement and septic arthritis. Removal of all thorns with partial or total synovectomy is essential in definitive treatment. Arthroscopy is the most valuable method of meeting both diagnostic and therapeutic purposes as it provides the best visibility of the joint with lower morbidity. © 2002 by the Arthroscopy Association of North America

An approximation to the stress distribution analysis for anisotropic clayey soil

Although estimation of a stress distribution in a soil mass assumed as an anisotropic medium gives more realistic results but it is impractical since many elastic parameters are required to be measured. Possibility of more practical way of estimation of a stress distribution, including cross-anisotropy in a different and simpler manner is investigated in this research. In this study a new anisotropic parameter, s, was presented into the theoretical deduction. To see the performance of the proposed method, five independent cross-anisotropic elastic parameters such as EV, EH,?VH,?HH, GVH and anisotropic parameter, s, of a clayey soil were measured and stress distributions under the center of uniformly distributed circular area were portrayed for the same soil. In this frame, Finite Element Method (with crossanisotropic linear elastic material model), the proposed method, Boussinesq and Westergaard solutions were carried out and results were compared. It is found that the stresses obtained by the proposed way are compatible with the other solutions and also the stresses agreed with that of FEM analysis beneath a certain depth. © 2009 Academic Journals

Critical-state parameters of an unsaturated residual clayey soil from Turkey

This paper deals with the evaluation of the critical-state parameters with respect to the matric suction for saturated and unsaturated undisturbed residual clayey soils from Turkey. In order to conduct the unsaturated triaxial compression testing procedures a conventional triaxial compression apparatus was redesigned. The data for critical-state conditions from these tests are presented with respect to matric suction, based on the critical-state parameters of M, qo, ?, ?, which is commonly proposed by many authors. The critical state of the unsaturated samples is compared with that of the saturated samples. This experimental study has demonstrated that matric suction has no influence on parameters of M and ?. The parameters of M and ? are approximately 0.85 and 0.074 respectively for saturated and unsaturated conditions. The relationships between matric suction (ua - uw) and the intercepts qo and ? have been observed as nonlinear, and thus they can be defined as a function of matric suction (ua - uw). Furthermore, a method is developed to predict the intercepts q0 according to matric suction for unsaturated clayey soils. © 2007 Elsevier B.V. All rights reserved

Exenatide reduces TNF-? expression and improves hippocampal neuron numbers and memory in streptozotocin treated rats

PubMed ID: 26386291Recent studies suggest a possible link between type 2 diabetes and Alzheimer's disease (AD). Glucogan-like peptide 1 (GLP-1) facilitates insulin release from pancreas under hyperglycemic conditions. In addition to its metabolic effects, GLP-1 and its long-lasting analogs, including exenatide can stimulate neurogenesis and improve cognition in rodent AD model. The aim of the present study was to investigate the effects of exenatide on hippocampal cellularity, cognitive performance and inflammation response in a rat model of AD. Fourteen rats were used to create AD model using intracerebroventricular (ICV) streptozotocin (STZ) infusion while 7 rats were administered 0.9% NaCl only (sham-operated group). Following stereotaxic surgery, STZ received rats were randomly distributed into two groups, and treated with either saline or exenatide 20 µgr/kg/day through intraperitoneally for two weeks. Then, cognitive performance (passive avoidance learning), brain tumor necrosis factor alpha (TNF-?) levels, choline acetyltransferase (ChAT) activity and hippocampal neuronal count were determined. While the brain TNF-? levels were significantly high in the saline-treated STZ group, exenatide treatment suppressed the increase in TNF-? levels. Saline-treated STZ group showed reduced ChAT activity compared to sham group. However, exenatide significantly preserved brain ChAT activity. The cognitive performance was also impaired in saline group while exenatide improved memory in rats. Moreover, exenatide treatment significantly prevented the decrease in hippocampal neurons. Overall, the results of the present study clearly indicated exenatide might have beneficial effects on impaired cognitive performance and hippocampal neuronal viability in AD by suppressing the inflammation response and increasing cholinergic activity. © 2015 Published by Elsevier B.V

A Noble-Metal-Free Heterogeneous Photosensitizer-Relay Catalyst Triad That Catalyzes Water Oxidation under Visible Light

An entirely earth-abundant chromophore-relay water oxidation catalyst triad system, which is robust and efficient at neutral pH, is presented. The synthesis involves the coordination of a porphyrin derivative to a bridging Fe(CN)(5) group, which is then reacted with Co ions to prepare a covalently linked chromophore-Prussian blue analogue assembly. Light-driven water oxidation studies in the presence of an electron scavenger indicate that the triad is active and it maintains a steady activity for at least three hours. Transient absorption experiments and computational studies reveal that the Fe(CN)(5) group is more than a linker as it takes part in electron-transfer and co-operates with porphyrin in the charge separation process