Intraocular oxygen and antioxidant status: New insights on the effect of vitrectomy and glaucoma pathogenesis

PURPOSE: The purpose of this study was to investigate correlations of partial pressure of oxygen (pO METHODS: This prospective, cross-sectional study stratified patients (n = 288 eyes) by lens and vitreous status and the presence of primary open-angle glaucoma for statistical analyses. Intraocular pO RESULTS: Following prior pars plana vitrectomy, pO CONCLUSIONS: Increased p

Capsaicin-Induced Ca2+ Influx and Constriction of the Middle Meningeal Artery

Research in the past on transient receptor potential cation channel subfamily V member 1 (TRPV1) has been limited to mainly nervous tissue TRPV1 because of the channel’s role in pain perception. Here, we studied the potential role of TRPV1 in vascular smooth muscle. We have observed that capsaicin, a TRPV1 agonist, induced constriction of the middle meningeal artery (MMA). Our goal was to decipher the mechanism of capsaicin-induced constriction of the MMA. Arterial diameter measurements showed that constriction due to 100 nM capsaicin (65.4% ± 3.7, n=7) was significantly diminished in the presence of the voltage-dependent calcium channel (VDCC) blocker 100 µM diltiazem (43.1% ± 8.1, n=7). Capsaicin-induced constriction was not significantly altered in the presence of the sarco/endoplasmic reticulum calcium transport ATPase (SERCA) inhibitor 30 µM cyclopiazonic acid (63.7 ± 9.0%, n=5) compared to control arteries (58.4 ± 8.6%, n=5). The unaltered capsaicin-induced constriction of the MMA in the presence of a SERCA inhibitor suggests that calcium-induced calcium release does not contribute to the overall calcium influx mechanism within the smooth muscle cells of the MMA. The diminished capsaicin-induced constriction of the MMA in the presence of a VDCC blocker suggests that sodium entry through TRPV1 channels can possibly lead to the membrane potential depolarization and increased activity of VDCCs causing further calcium influx. Furthermore, since the capsaicin effect was not abolished by the blockage of VDCCs, our data suggest that calcium entry through TRPV1 is sufficient to cause approximately 65% of the total constriction of the MMA in response to activation of TRPV1

A parallel downloading algorithm for redundant networks

In this paper, we study the downloading mechanism of BitTorrent (or BT), a P2P based popular and convenient parallel downloading software tool, point out some of its limitations, and propose an algorithm to improve its performance. In particular, we address the limitations of BT by using neighbours in P2P networks to resolve the redundant copies problem and to optimise the downloading speed. Our preliminary experiments show that the proposed enhancement algorithm works well

4,9,12,15-Tetra­oxa-3,5,8,10,14,16-hexa­aza­tetra­cyclo­[11.3.0.02,6.07,11]hexa­deca-1(16),2,5,7,10,13-hexaen-3-ium-3-olate monohydrate

The organic mol­ecule in the title monohydrate, C6N6O5·H2O, presents an almost planar configuration, the greatest deviation from the least-squares plane through the atoms being 0.061 (1) Å for the O atom within the seven-membered ring. Each water H atom is bifurcated, one forming two O—H⋯N hydrogen bonds and the other forming O—H⋯N,O hydrogen bonds. The result of the hydrogen bonding is the formation of supra­molecular layers with a zigzag topology that stack along [001]

Protective effect of glucosamine cyclohexyl ester on osteoarthritis in rat via targeting expressions of matrix metalloproteinase and tissue inhibitor of metalloproteinases-1

Purpose: To investigate the therapeutic effect of glucosamine cyclohexyl ester on osteoarthritis (OA) in a rat model.Methods: Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot assays were used to analyze the effect of glucosamine cyclohexyl ester on changes in mRNA and protein expressions of matrix metalloproteinase and tissue inhibitor of metalloproteinases-1 in isolated rat chondrocytes, and in a rat model of OA. The rat model of OA was prepared by injecting monoiodoacetate to Sprague-Dawley rats via intra-articular route.Results: Treatment of the chondrocytes with glucosamine cyclohexyl ester for 48 h prevented interleukin-1 β (IL-1β)-mediated increases in mRNA and protein  expressions in matrix metalloproteinases-1, -3 and -13, and also blocked IL-1β-induced decreases in mRNA and protein expressions of tissue inhibitor of metalloproteinase-1. Glucosamine cyclohexyl ester treatment also blocked the onset of morphological changes such as irregular surface, adhesion of tissues andpresence of osteophytes in the femoral condyle surface of the OA rats. Mankin score for control, OA and glucosamine cyclohexyl ester treatment groups were 0.98 ± 0.15, 8.35 ± 0.88 and 2.39 ± 0. 67 (p = 0.002), respectively. Treatment of OA rats with glucosamine cyclohexyl ester also inhibited increases in the activities of matrix metalloproteinases-1, -3 and -13, and decreases of tissue inhibitor of metalloproteinase-1 mRNA and protein expressions. Treatment of chondrocytes and OA rats with IL-1β caused no significant changes in the levels of H3K27 and H4K8.Conclusion: These results show that glucosamine cyclohexyl ester prevents OA by targeting the expressions of matrix metalloproteinases-1, -3 and -13 and tissue inhibitor of metalloproteinases-1.Keywords: Metalloproteinases, Interleukin, Mankin score, Osteoarthritis, Cartilag