Total syntheses of surinone B,alatanones A–B,and trineurone A

The total syntheses of four polyketides, surinone B (1), alatanones A–B (2–3), and trineurone A (4) were accomplished through an efficient and unified strategy via one-pot C-acylation reaction coupling 1,3-cyclohexadiones with EDC-activated acids under mild conditions. Alatanone A (2) was found to be a potent anti-microbial agent against Gram-positive and Gram-negative bacteria with MIC 31.25 μg/ml while alatanone B (3) was found to be a potent anti-fungal agent against Cladosporium cladosporioides with MIC 62.5 μg/ml compared to cycloheximide MIC 125 μg/ml. Our methodology allows performing kilogram scale of these scarce polyketides for the development of new antimicrobials.     

P24 Effect of Nonintellectual Factors on Medical Students and Analysis of Related Strategies for Teaching in Pharmacology

Investigation of college students＇ nonintellectual ability was organized and group survey was adopted. The results showed that the nonintellectual ability of medical college students display an active tendency on total, but the development of inner factor is imbalanced. There are significant differences of nonintellectual ability between different student groups. The boys＇ nonintellectual abilities are higher than girls＇ , special course students＇ nonintellectual ability is higher than under-graduated students＇ The results of our survey can give us some related inspirations and suggestions. The teaching content and knowledge structure should be adjusted according to the student groups of different nonintellectual ability. The critical thinking ability of the students should be cultivated by reforming teaching methods and making full use of teachers＇ leading roles. The students＇ interest in learning should be stimulated by renewing teaching devices, which makes students change their passive study into active study.     

The effects of some α-adrenoceptor antagonists on the responses of the canine saphenous vein to B-HT 933, UK-14304 and methoxamine

Summary The benzoquinolizines Wy 25309, Wy 26703 and Wy 27127, previously reported as potent antagonists at presynaptic ₂-adrenoceptors were also potent antagonists of B-HT 933 in isolated saphenous veins of the dog confirming their activity at post synaptic ₂-adrenoceptors. Yohimbine was a more potent antagonist of B-HT 933 in isolated saphenous vein than were the Wy compounds or idazoxan contrasting with the reported potencies of these compounds at presynaptic sites in rat vas deferens and raising the possibility of differences between pre- and postsynaptic ₂adrenoceptors. Contractions of the saphenous vein were observed with high concentrations of idazoxan. Send offprint requests to K. F. Rhodes at the above address     

PKPD modelling to predict altered disposition of 1α,25-dihydroxyvitamin D3 in mice due to dose-dependent regulation of CYP27B1 on synthesis and CYP24A1 on degradation

Background and Purpose

Concentrations of 1α,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃], the active ligand of the vitamin D receptor, are tightly regulated by CYP27B1 for synthesis and CYP24A1 for degradation. However, the dose-dependent pharmacokinetic (PK)-pharmacodynamic (PD) relationship between these enzymes and 1,25(OH)₂D₃ concentrations has not been characterized.

Experimental Approach

The pharmacokinetics of 1,25(OH)₂D₃ were evaluated after administration of single (2, 60 and 120 pmol) and repeated (2 and 120 pmol q2d ×3) i.v. doses to male C57BL/6 mice. mRNA expression of CYP27B1 and CYP24A1 was examined by quantitative PCR and 1,25(OH)₂D₃ concentrations were determined by enzyme immunoassay.

Key Results

CYP27B1 and CYP24A1 changes were absent for the 2 pmol dose and biexponential decay profiles showed progressively shorter terminal half-lives with increasing doses. Fitting with a two-compartment model revealed decreasing net synthesis rates and increasing total clearances with dose, consistent with a dose-dependent down-regulation of renal CYP27B1 and the induction of renal/intestinal CYP24A1 mRNA expression. Upon incorporation of PD parameters for inhibition of CYP27B1 and induction of CYP24A1 to the simple two-compartment model, fitting was significantly improved. Moreover, fitted estimates for the 2 pmol dose, together with the PD parameters as modifiers, were able to predict profiles reasonably well for the higher (60 and 120 pmol) doses. Lastly, an indirect response model, which considered the synthesis and degradation of enzymes, adequately described the PK and PD profiles.

Conclusions and Implications

The unique PK of exogenously administered 1,25(OH)₂D₃ led to changes in PD of CYP27B1 and CYP24A1, which hastened the clearance of 1,25(OH)₂D₃.Tables of Links

Fabrication and characterization of extruded and spheronized beads containing carbopol® 974P,NF resin

Carbopol® 974P, NF resin is a synthetic, cross-linked, acrylic acid polymer. It becomes tacky when wetted, which introduces handling difficulties with techniques involving water or other fluid. To reduce tack, the water for wetting was replaced by an aqueous solution of a strong electrolyte. The effect of the concentration and type of electrolyte on the adhesive force of the wet mass was measured. A correlation was found between the charge density of the cation and the minimum salt concentration necessary to eliminate problems associated with tack. Beads containing chlorpheniramine maleate, Carbopol®, Avicel PH101, and electrolytes were successfully manufactured by extrusionspheronization. The Carbopol® concentration, as well as the pH and ionic strength of the dissolution medium and the rotation speed of the paddles, can modify drug release.     

Zaprinast activates MAPKs, NFκB, and Akt and induces the expressions of inflammatory genes in microglia

Previously, the authors reported that zaprinast, an inhibitor of cGMP-selective phosphodiesterases, induced the secretions of TNF-α and IL-1β by microglia and enhanced the induction of iNOS by lipopolysaccharide (LPS). In this study, the signaling mechanism responsible for microglial activation by zaprinast was investigated and the effects of zaprinast and LPS on microglial activation were compared. Zaprinast was found to activate ERK1/2, p38 MAPK, JNK, NFκB, and PI3K/Akt, and subsequently, induce the mRNA expressions of IL-1α, IL-1β, TNF-α, CCL2, CCL4, CXCL1, CXCL2, and CD14. Associations between signaling pathways and gene expressions were examined by treating microglia with signal inhibitors. PDTC inhibited the induction of all the above genes by zaprinast, and SB203580 inhibited all genes except CXCL1. SP600125, PD98059, and LY294002 inhibited the induction of at least CCL2. Microglial activation by zaprinast was then compared with full-blown activation by LPS. The zaprinast-induced phosphorylations of MAPKs and IκB were less prompt than LPS-induced phosphorylations. IκB degradation by LPS was significant at 10min and did not return to normal, whereas zaprinast induced a later, transient degradation. LPS induced the mRNA expressions of IL-1β, TNF-α, IL-6, CCL2, iNOS, and COX-2, and although zaprinast significantly induced the expressions of all except IL-6 and iNOS, these inductions were far less than those induced by LPS. Collectively, zaprinast was found to upregulate microglial activity mainly via NFκB and p38 MAPK signaling and the subsequent expressions of inflammatory genes. Although, zaprinast was found to have obvious effects on microglia, these were weaker than the effects of LPS.     

Aflatoxin,Fumonisin and Shiga Toxin-Producing Escherichia coli Infections in Calves and the Effectiveness of Celmanax?/Dairyman’s Choice? Applications to Eliminate Morbidity and Mortality Losses

Mycotoxin mixtures are associated with Shiga toxin-producing Escherichia coli (STEC) infections in mature cattle. STEC are considered commensal bacteria in mature cattle suggesting that mycotoxins provide a mechanism that converts this bacterium to an opportunistic pathogen. In this study, we assessed the mycotoxin content of hemorrhaged mucosa in dairy calves during natural disease outbreaks, compared the virulence genes of the STECs, evaluated the effect of the mucosal mycotoxins on STEC toxin expression and evaluated a Celmanax^®/Dairyman’s Choice™ application to alleviate disease. As for human infections, the OI-122 encoded nleB gene was common to STEC genotypes eliciting serious disease. Low levels of aflatoxin (1–3 ppb) and fumonisin (50–350 ppb) were detected in the hemorrhaged mucosa. Growth of the STECs with the mycotoxins altered the secreted protein concentration with a corresponding increase in cytotoxicity. Changes in intracellular calcium indicated that the mycotoxins increased enterotoxin and pore-forming toxin activity. A prebiotic/probiotic application eliminated the morbidity and mortality losses associated with the STEC infections. Our study demonstrates: the same STEC disease complex exists for immature and mature cattle; the significance of the OI-122 pathogenicity island to virulence; the significance of mycotoxins to STEC toxin activity; and, finally, provides further evidence that prebiotic/probiotic applications alleviate STEC shedding and mycotoxin/STEC interactions that lead to disease.     

The Expression and Clinical Significance of PPAR-γ, p27kip1 and Skp2 in Hepatocellular Carcinoma

目的:探讨过氧化物酶增殖物激活受体(PPAR)-γ、p27kip1和细胞S期激酶相关蛋白(Skp)2蛋白在肝癌发生发展过程中的作用.方法:肝细胞癌组织标本57例(肝癌组)和正常肝组织标本(对照组)20例.采用免疫组织化学方法检测2组PPAR-γ、p27kip1及Skp2蛋白的表达,分析它们之间及其与肝癌临床病理特征的关系.结果:肝癌组PPAR-γ及Skp2蛋白的阳性表达率高于对照组,p27kipl蛋白阳性表达率低于对照组(P＜0.05),PPAR-γ蛋白与Skp2、P27kip1蛋白在不同TNM分期中的表达差异均有统计学意义(P＜0.05).PPAR-γ蛋白与Skp2、p27kip1蛋白表达无相关性(P＞0.05);Skp2与p27kip1蛋白的表达呈负相关(r=-0.307,P=0.020).Skp2蛋白低表达组的1、3、5年生存率高于高表达组(P＜0.001).结论:PPAR-γ和Skp2蛋白表达与肝细胞癌的恶性生物学行为密切相关,Skp2可作为判断肝细胞癌预后的指标.     

The disintegrin,trimucrin, suppresses LPS-induced activation of phagocytes primarily through blockade of NF-κB and MAPK activation

In addition to antiplatelet activity, disintegrin, a small-mass RGD-containing polypeptide, has been shown to exert anti-inflammatory effects but the mechanism involved remains unclear. In this study, we report that trimucrin, a disintegrin from the venom of Trimeresurus mucrosquamatus, inhibits lipopolysaccharide (LPS)-induced stimulation of THP-1 and RAW 264.7 cells. We also investigate the underlying mechanism. Trimucrin decreased the release of proinflammatory cytokines including tumor necrosis factor α (TNFα), interleukin-6 (IL-6), nitric oxide, and reactive oxygen species (ROS), and inhibited the adhesion and migration of LPS-activated phagocytes. Trimucrin significantly blocked the expression of nuclear factor kappaB (NF-κB)-related downstream inducible enzymes such as inducible nitric oxide synthase (iNOS) and COX-2. In addition, its anti-inflammatory effect was associated with the decreased mitogen-activated protein kinase (MAPK) phosphorylation. Furthermore, trimucrin concentration dependently inhibited LPS-induced phosphorylation of focal adhesion kinase (FAK), PI3K, and Akt. Trimucrin also reversed the DNA-binding activity of NF-κB by suppressing the LPS-induced nuclear translocation of p65 and the cytosolic IκB release. Flow cytometric analyses showed that trimucrin bound to cells in a concentration-dependent manner. The anti-αVβ3 mAb also specifically decreased the binding of fluorescein isothiocyanate (FITC)-conjugated trimucrin. Binding assays demonstrated that integrin αVβ3 was the binding site for trimucrin on THP-1 and RAW 264.7 cells. In conclusion, we showed that trimucrin decreases the inflammatory reaction through the attenuation of iNOS expression and nitric oxide (NO) production by blocking MAP kinase and the NF-κB activation in LPS-stimulated THP-1 and RAW 264.7 cells.     

Anti-inflammatory effect of 2-methoxy-4-vinylphenol via the suppression of NF-κB and MAPK activation,and acetylation of histone H3

Although inflammation acts as host defense mechanism against infection or injury and is primarily a self limiting process, inadequate resolution of inflammatory responses leads to various chronic disorders. This work aimed to elucidate the anti-inflammatory effects of 2-methoxy-4-vinylphenol (2M4VP) isolated from pine needles in LPS-stimulated RAW264.7 cells. Some key pro-inflammatory mediators including nitric oxide (NO), prostaglandins (PGE₂), inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2) were studied by sandwich ELISA and western blot. In addition, suppression of NF-κB and MAPK activation, and histone acetylation was studied by western blot analysis and immunostaining. 2M4VP dosedependently inhibited NO and PGE₂ production and also blocked LPS-induced iNOS and COX-2 expression. In addition, 2M4VP potently inhibited the translocation of NF-κB p65 into the nucleus by IκB degradation following IκB-α phosphorylation and the phosphorylation of MAPKs such as p38, ERK1/2, and JNK. Also, 2M4VP inhibited hyper-acetylation of histone H3 (Lys9/Lys14) induced by LPS. Taken together, our results suggest that 2M4VP, a naturally occurring phenolic compound, exert potent anti-inflammatory effects by inhibiting LPS-induced NO, PGE₂, iNOS, and COX-2 in RAW264.7 cells. These effects are mediated by suppression of NF-κB and MAPK activation and histone acetylation.     

Asparaginase induces selective dose- and time-dependent cytotoxicity,apoptosis, and reduction of NFκB expression in oral cancer cells

Asparaginase is fundamental to the treatment of haematological malignancies. However, little has been studied on the effects that asparaginase could exert on solid tumours. Thus, this study aimed to evaluate the effects of asparaginase on an oral carcinoma cell line. The cytotoxicity of asparaginase in SCC-9 (tongue squamous cell carcinoma) and HaCaT (human keratinocyte) cell lines was evaluated with MTT cell viability assay. The cells were treated with asparaginase at 0.04, 0.16, 0.63, 1.0, 1.5, 2.5, and 5.0 IU/mL. Dose-response curves and IC₅₀ values were obtained and the Tumour Selectivity Index (TSI) was calculated. The effect of asparaginase on procaspase-3 and nuclear factor κB (NFκB) expression was evaluated with western blot because it was reported that the overexpression of NFκB has been shown to contribute to tumour cell survival, proliferation, and migration. Caspase 3/7 staining was performed to identify cell death using flow cytometry. Effective asparaginase concentrations were lower for SCC-9 cells when compared to HaCaT cells. The cytotoxicity results at 48 and 72 hours were significantly different for SCC-9 cells. The TSI indicated that asparaginase was selective for the tumour cells. A decrease in procaspase-3 and NFκB protein levels was observed in SCC-9 cells. Furthermore, asparaginase resulted in significant apoptosis after 48 and 72 hours. Based on these results, asparaginase was cytotoxic in a dose- and time-dependent manner, induces apoptosis, and reduces NFκB expression in oral cancer cells. These results encourage further studies on the effectiveness of this enzyme as a treatment for solid tumours, especially head and neck cancer.     

Roles of some antioxidants in modulation of cardiac myopathy induced by sodium nitrite via down-regulation of mRNA expression of NF-κB,Bax, and flt-1 and suppressing DNA damage

The underlying pathology of cardiac damage involves various molecular and signaling pathways. Therefore, this study aimed to explore the role of Quercetin (Querc), alone or in combination with Melatonin (Melat) against cardiac damage induced by sodium nitrite (Sod nit), as well as to elucidate different signaling pathways. Querc and Melat were injected intraperitoneally (i.p.), followed by induction of hypoxia in rats by using a single dose of Sod nit (60?mg/kg, s.c.). Treatment with Sod nit significantly decreased hemoglobin (Hb) levels in blood. Pretreatment of hypoxic rats with Querc and/or Melat elevated the declined Hb concentration. The forementioned antioxidants also successfully ameliorated the alteration of heat shock protein 70 (HSP-70) and markers of cardiac injury, including troponin T (Trop. T), creatine kinase-MB (CK-MB), tumor necrosis factor-α (TNF α), and C-reactive protein (CRP) in the rats serum. Furthermore, RT-PCR revealed that these antioxidants successfully modulated mRNA expression of NF-κB, Bax, Bcl-2, and flt-1. They also regulated vascular endothelial growth factor (VEGF), the apoptosis marker caspase 3, and oxidative DNA damage in cardiac tissue, compared to Sod nit-intoxicated rats. The present biochemical results are reinforced by histopathological examination. In Conclusion: The results reflected that treatment with Querc in combination with Melat was most effective in improving Sod nit-toxicity induced cardiac damage, thus confirming the promising role of this combination as an effective treatment for cardiac damage induced by other cardio-toxic agents.