To investigate the effects of Musk glucoprotein on platelet activating factor (PAF) production and the concentration of cytosolic free Ca2+ in polymorphonuclear leukocytes of rat.An in vitro incubation system was used, production of PAF and activity of acetyl transferase were measured by isotope incorporation, the concentration of cytosolic free Ca2+ was quantitated using the fluorescent Ca2+ indicator Fura-2.Musk-1 at concentration of 1-100 micrograms.ml-1 can significantly inhibit production of PAF, activity of acetyl transferase and the increase of cytosolic Ca2+ concentration in polymorphonuclear leukocytes of rat.Part of mechanisms underlying antiinflammatory action of Musk-1 is through inhibiting the synthesis of PAF and the increase of cytosolic Ca2+ level.
Cell adhesion and mitogenic growth factors are jointly required for cell proliferation of almost all cell types. Cell proliferation reflects continued progression through the cell cycle, and progression through the cell cycle is mediated by the sequential activation of cyclin-dependent kinases (cdks). Cell cycle progression through G1 phase is mediated by a subset of the cyclin-dependent kinases: cyclin D-cdk4 or cyclin D-cdk6, cyclin E-cdk2, and cyclin A-cdk2. This chapter describes the methods for analyzing the regulation of G1 phase cyclins, cdk inhibitors, and cdk activities. It stimulates cell cycle progression in monolayer, the trypsinized cells are seeded in untreated tissue culture dishes in serum-containing medium or in matrix-protein coated dishes. Trypsin-dependent activation of ERKs should be considered when setting up experiments designed to examine time- or anchorage-dependent ERK activation.
Weakly tilted fiber Bragg gratings (W-TFBGs) with a certain tilted angle are inscribed in the Ge-doped cladding rods of all-solid photonic band-gap fibers (AS-PBGF) by UV illumination. There are couplings not only forward-propagating LP01 mode to counter-propagating LP01 mode but also the couplings to counter-propagating high order supermodes based on tilted refractive index modulation. The responses of the W-TFBGs to temperature and bend are investigated. The results indicate that the resonance peaks will shift red-side with increasing temperatures, and the sensitivities of different resonance peaks are very close in the same grating. When the bend is applied, the grids of W-TFBG will be compressed or stretched. Two resonance peaks will shift with increasing curvatures, which is related to the orientation of curvature. Therefore, it is potential to work as a directional bend sensor. For the fiber grating with high-order supermodes coupling, it could form fiber grating array by different levels. If every grating has individual response to surrounding, such a single W-TFBG could be used for one point and multi-parameter measurement. In addition, this work provides some insights into the mechanisms that contribute to the measured properties of TFBG in the photonic crystal fiber. It is also an effective method to investigate supermode properties of photonic crystal fiber.
The water soluble fraction (WSF) of musk was shown to decrease the vitamin C content of the adrenal gland in mice and to increase plasma corticosterone levels in rats. The anti-inflammatory effect of WSF was not affected by hypophysectomy in the rat but was completely abolished by adrenalectomy in mice, indicating that the adrenal gland may play an important role in mediating the anti-inflammatory effect of musk. The WSF was capable of inhibiting ADP or collagen-induced platelet aggregation in rats. In the meantime, there was a potentiation of immunohemolysis in mice and an elevation of the plasma level of cAMP in rats. The implications of these changes in the anti-inflammatory effects of musk are discussed.
Matrine, an active constituent of the Chinese herb, Sophora flavescens Ait., and it is known for its antioxidant, anti-inflammatory and antitumor activities. It has been demonstrated that matrine exerts protective effects against heart failure by decreasing the expression of caspase-3 and Bax, and increasing Bcl‑2 levels. In this study, we aimed to determine whether these protective effects of matrine can be applied to cerebral ischemia. Following 7 successive days of treatment with matrine (7.5, 15 and 30 mg/kg) and nimodipine (1 mg/kg) by intraperitoneal injection, male Institute of Cancer Research (ICR) mice were subjected to middle cerebral artery occlusion (MCAO). Following reperfusion, the neurobehavioral score and brain infarct volume were estimated, and morphological changes were analyzed by hematoxylin and eosin (H&E) staining and electron microscopy. The percentage of apoptotic neurons was determined by flow cytometry. The levels of oxidative stress were assessed by measuring the levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), and the total antioxidant capacity (T-AOC). Western blot analysis and immunofluorescence staining were used to examine the expression of the apoptosis-related proteins, caspase-3, Bax and Bcl-2. Our results revealed that pre-treatment with matrine significantly decreased the infarct volume and improved the neurological scores. Matrine also reduced the percentage of apoptotic neurons and relieved neuronal morphological damage. Furthermore, matrine markedly decreased the MDA levels, and increased SOD, GSH-Px and CAT activity, and T-AOC. Western blot analysis and immunofluorescence staining revealed a marked decrease in caspase-3 expression and an increase in the Bcl-2/Bax ratio in the group pre-treated with matrine (30 mg/kg) as compared with the vehicle-treated group. The findings of the present study demonstrate that matrine exerts neuroprotective effects against cerebral ischemic injury and that these effects are associated with its antioxidant and anti-apoptotic properties.
Web applications have been increasingly deployed on the Internet. How to effectively allocate system resources to meet the Service Level Objectives (SLOs) is a challenging problem for Web application providers. In this article, we propose a scheme for automated performance control of Web applications via dynamic resource allocations. The scheme uses a queueing model predictor and an online adaptive feedback loop that enforces admission control of the incoming requests to ensure the desired response time target is met. The proposed Queueing-Model-Based Adaptive Control approach combines both the modeling power of queueing theory and the self-tuning power of adaptive control. Therefore, it can handle both modeling inaccuracies and load disturbances in a better way. To evaluate the proposed approach, we built a multi-tiered Web application testbed with open-source components widely adopted in industry. Experimental studies conducted on the testbed demonstrated the effectiveness of the proposed scheme.