T‐bet is a new synergistic meeting point for the BCR and TLR9 signaling cascades

The importance of the BCR and TLR9 in autoimmunity and in the production of auto‐antibodies is well established but the underlying molecular mechanism still needs to be determined. Here, we aim to characterize the BCR‐TLR9 cross‐talk by its effect on T‐bet, as T‐bet is activated and regulated by both receptors and has an important role in class‐switching to pathological IgG2a in mice. Using primary mouse B cells, we demonstrate that T‐bet expression is synergistically elevated by the cross‐talk between the BCR and TLR9. To test the effect of this synergy on IgG2a‐switching, the levels of switched B cells were checked by functional tests. We found that BCR costimulation had no additional effect on TLR9‐induced IgG2a expression, however the expression of Rad51 was synergistically increased. To check the biological significance of the synergy, we compared T‐bet expression in B cells from healthy and collagen‐induced arthritis mice but no differences were found. Taken together, we demonstrate here that signaling cascades driven by the BCR and TLR9 have a newly identified meeting point at T‐bet. The two cascades act synergistically on T‐bet; however additional signals may be needed to induce prolonged functional responses such as class‐switch recombination.     

PP242通过下调AKt/mTOR/4EBP1/eIF4E信号通路与柔红霉素存在协同抗急性白血病作用

目的通过研究PP242单药及与柔红霉素(DNR)联合抗急性白血病的效应及作用机制,探寻急性白血病治疗的新方法。方法以NB4、THP-1、SUP-B15三种急性白血病细胞株为研究模型,采用MTT药物敏感试验检测PP242、DNR单药及两药联合的抗细胞增殖作用;Western Blot方法分析药物对Akt/mTOR/4EBP1/eIF4E信号通路关键点蛋白磷酸化的表达水平的影响;7-甲基鸟嘌呤帽亲和分析法分析药物对eIF4F翻译起始复合物中4EBP1、eIF4E、eIF4G表达的影响;流式细胞学检测PP242的促凋亡作用。结果 (1)MTT显示PP242、DNR单药对急性白血病细胞株均有显著的抗细胞增殖作用,而100 nmol/L的PP242与DNR联合使IC_(50)下降明显,计算协同指数均小于1,表明两药存在协同作用。(2)Western Blot显示PP242可有效下调Akt/mTOR/4EBP1/eIF4E轴的关键磷酸化蛋白及Mcl-1表达,而DNR却反馈上调这个通路的蛋白表达,PP242可协同DNR下调这条通路表达。(3)7-甲基鸟嘌呤帽亲和分析法显示PP242可增加eIF4E与4EBP1的结合,减少与eIF4G的结合,从而抑制eIF4F的形成,而DNR单药并没有这个作用。(4)流式细胞学显示PP242可促进细胞凋亡发生。结论 PP242单药可抑制三种急性白血病细胞株的增殖,具有明显的抗急性白血病作用,分析其可能作用机制为:通过抑制Akt/mTOR/4EBP1/e IF4E信号通路活性,抑制eIF4F翻译起始复合物形成以及促进细胞凋亡的发生。PP242与DNR联合有协同抗急性白血病作用。     

Thymus vulgaris essential oil and thymol inhibit biofilms and interact synergistically with antifungal drugs against drug resistant strains of Candida albicans and Candida tropicalis

Role of biofilm in disease development and enhance tolerance to antifungal drugs among Candida species has necessitated search for new anti-fungal treatment strategy. Interference in pathogenic biofilm development by new antifungal compounds is considered as an attractive anti-infective strategy. Therefore, the objective of this study was to evaluate Thymus vulgaris essential oil and its major active compound, thymol for their potential to inhibit and eradicate biofilms alone and in combination with antifungal drugs against Candida spp. with especial reference to Candida tropicalis. Anti-candidal efficacy of T. vulgaris and thymol in terms of minimum inhibitory concentration (MIC) was first determined to select the sub-MICs against C. albicans and C. tropicalis. Biofilm formation in the presence and absence of test agents was determined in 96-well microtiter plate by XTT reduction assay and effect of essential oils at sub-MICs of the test agents on biofilm development on glass surface was analysed by light and scanning electron microscopy. Synergistic interaction between essential oils and antifungal drugs were studied by checkerboard method. Effect of sub-MIC of T. vulgaris (0.5 × MIC) and thymol (0.5 × MIC) on biofilm formation showed a significant reduction (P < 0.05) in biofilms. Light microscopy and SEM studies revealed disaggregation and deformed shape of C. albicans biofilm cells and reduced hyphae formation in C. tropicalis biofilm cells at sub-MICs of thymol. Significant effect of T. vulgaris and thymol was also recorded on pre-formed biofilms of both C. albicans and C. tropicalis. T. vulgaris and thymol also showed synergy with fluconazole against both in planktonic and biofilm mode of growth of C. albicans and C. tropicalis. However, synergy with amphotericin B is clearly evident only in planktonic Candida cells. Thyme oil and thymol alone or in combination with antifungal drugs can act as promising antibiofilm agent against drug resistant strains of Candida species and needs further in vivo study to synergise its therapeutic efficacy.     

蛋氨酸酶联合顺铂协同抑制人肺腺癌细胞GLC生长作用

目的：纯化重组蛋氨酸酶并探讨其联合化疗药物顺铂对人肺腺癌GLC细胞生长的协同抑制效应．方法对原核表达体系pGEX-4T-1-Met/Dh5a菌液破碎后上清过纯化柱（GST）纯化后,采用MTT比色法测定重组蛋氨酸酶与顺铂联合应用对GLC细胞增殖的抑制作用,采用金正均法计算q值判断两药合用是否具有协同作用．结果重组蛋氨酸裂解酶浓度为0.22 mg/mL,纯度达95%,活性为0.568 IU/mg．给药72 h后单用顺铂对GLC细胞抑制率为24.80%,单用蛋氨酸酶抑制率为27.49%,两药合用抑制率为66.80%．=1.47＞1.15,表现出明显协同作用．结论蛋氨酸酶及顺铂均有抑制GLC增殖作用,并且两者联合使用存在协同作用．     

HIFU联合脂质纳米氟碳液滴消融兔肝的实验研究

目的 探讨脂质纳米氟碳液滴增效HIFU消融兔肝脏的空化活动及术后病理学变化。方法 首先制备全氟戊烷脂质纳米氟碳液滴(L-PFP);然后将24只正常新西兰兔随机分为对照组(单纯HIFU组)和L-PFP组;在 B 超引导下进行HIFU定点消融兔肝脏(超声能量：900 J);通过被动空化检测系统(PCD)监控空化活动;分别将消融即刻、1d、3d、7d的兔肝脏标本取出进行H E染色,观察消融灶转归过程中的病理学变化。结果 经耳缘静脉注射L-PFP后HIFU 辐照兔肝脏所产生的空化泡群更明显,其灰度变化值为对照组的1.93倍,累积瞬态空化剂量为对照组的6.3倍,空化活动表现强烈;大体病理及H E结果显示L-PFP组造成的组织损伤严重,细胞变性更为彻底,炎性反应更为强烈;单纯HIFU组消融灶7d修复为正常组织,转归所需时间显著短于L-PFP组。结论 脂质纳米氟碳液滴通过增强空化效应有效提高HIFU消融效果,延长消融灶转归所需时间。     

Antinociception produced by receptor selective opioids. Modulation of supraspinal antinociceptive effects by spinal opioids

This study evaluated the antinociceptive effects produced when different combinations of supraspinal μ- and δ-opioid agonist were co-administered with spinal μ-, δ-, and κ-opioid agonist. Using the Randall-Selitto paw-withdrawal test, in the rat, changes in nociceptive thresholds were measured following co-administration of sequentially increasing i.c.b. doses of either DAMGO or DPDPE with a low-antinociceptive dose of intrathecal DAMGO, DPDPE, or U50,488H. Antinociceptive synergy (i.e. a more than additive antinociceptive effect) was demonstrated with all of the combinations tested except for supraspinal DPDPE co-administered with spinal DAMGO. The results of this study provide support for the suggestion that supraspinal and spinal antinociceptive mechanisms share, in part, common neural circuits. Marked differences in the overall magnitude of the antinociceptive effects produced by the various combinations of opioid agonists were demonstrated through a secondary analysis of the data. When sequentially increasing i.c.v. doses of DAMGO were administered, significantly larger increases in nociceptive thresholds were observed with co-administration of intrathecal injections of low antinociceptive doses of either DAMGO or U50,488H compared to DPDPE. In contrast, when DPDPE was administered supraspinally, the largest increases in nociceptive thresholds were demonstrated with co-administration of DPDPE at the spinal site. The results of the secondary analysis provide support for the hypothesis that descending antinociceptive control systems activated by supraspinal administration of selective μ- and δ-opioid agonists interact, differently, with spinal μ-, δ, and κ-opioidergic mechanisms.     

Synergy between a NR2B receptor antagonist DHQ and 3-methyl-gabapentin in mice with neuropathic pain

The synergistic effect of a selective NR2B NMDA receptor antagonist, (-)-(R)-6-{2-[4-(3-Fluorophenyl)-4-hydroxy-1-piperidinyl]-1-hydroxyethyl-3,4-dihydro-2(1H)-quinolinone (DHQ), and a alpha 2 delta ligand, 3-methyl-gabapentin (3M-GBP), was investigated in the mouse partial sciatic nerve model. The interaction was observed after administration of DHQ and 3M-GBP combination at fixed dose ratios of 1:10 and 1:30 and the dose-response curves shifted approximately 13- and 17-fold leftward, respectively, from the theoretical additive values. However, a fixed dose ratio of 1:50 resulted only in an additive effect. These results indicate the synergistic interaction between DHQ and 3M-GBP in this animal model of neuropathic pain.     

Synergy of Irofulven in combination with various anti-metabolites,enzyme inhibitors,and miscellaneous agents in MV522 lung carcinoma cells: marked interaction with gemcitabine and 5-fluorouracil

The novel agent Irofulven (HMAF, NSC 683863) has demonstrated significant antitumor activity against solid tumors in various xenograft models and human clinical trials. The antitumor potential of combining irofulven with 72 different anti-metabolite, enzyme inhibiting, and miscellaneous agents was investigated in this study. The human lung carcinoma MV522 cell line and its corresponding xenograft model were used to evaluate the activity of irofulven in combination with these different agents. Irofulven in combination with select anti-metabolites, notably cytidine or adenine-derived agents, displayed strong synergistic activity in both in vitro and in vivo studies. Agents demonstrating strong synergistic interaction with irofulven included gemcitabine, cyclocytidine, cytarabine, fludarabine phosphate, cladribine, and 5-fluorouracil. Other anti-metabolites, enzyme inhibitors, and a variety of miscellaneous agents failed to interact beneficially when administered in combination with irofulven. The therapeutic activity of irofulven is enhanced considerably when irofulven is combined with select anti-metabolite agents, and further clinical evaluation of these combinations is warranted. The synergistic interaction with these combinations may stem from a variety of actions including inhibition of the nucleotide excision repair (NER) pathway, topoisomerase I activity, and caspase-dependent and independent induction of apoptosis.     

Assessment and modelling of antibacterial combination regimens

BackgroundThe increasing global prevalence of multidrug-resistant bacteria is forcing clinicians to prescribe combination antibiotic regimens to treat serious infections. Currently, the joint activity of a combination is quantified by comparing the observed and expected effects using a reference model. These reference models make different assumptions and interpretations of synergy. They fail to: (i) account for multiple bacterial subpopulations with differing susceptibilities; (ii) quantify or interpret the explicit interaction (synergy/antagonism) mechanisms; and (iii) accommodate spontaneous mutations.AimsTo develop better study designs, mathematical models, metrics and pharmacodynamic analyses to assist with the identification of highly active combinations that are translatable to the clinical context to address the mounting antibiotic resistance threat.SourcesPubMed, references of identified studies and reviews, and personal experience when evidence was lacking.ContentWe reviewed metrics and approaches for quantifying the joint activity of the combination. The first example is using experimental data from an in vitro checkerboard synergy panel to develop and illustrate a less model-dependent method for assessing combination regimens. In the second example a pharmacokinetic/pharmacodynamic model was developed using mechanism-based mathematical modelling and monotherapy and combination therapy data obtained from an in vitro hollow fibre infection model evaluating linezolid and rifampin regimens against Mycobacterium tuberculosis.ImplicationsMechanism-based mathematical approach provides an excellent platform for describing the time course of effect while taking into account the mechanisms of different antibiotics and differing pathogen susceptibilities. This approach allows for the future integration of ‘omics’ data describing host–pathogen interactions, that will provide a systems-level understanding of the underlying infectious process, and enable the design of effective combination therapies.     

风湿热应激前后雷公藤配伍金钱草抗炎增效减毒作用研究

目的:研究风湿热应激前后雷公藤配伍金钱草抗炎增效及减毒作用。方法:90只SPF级昆明小鼠随机分为正常对照组、角叉菜胶组、雷公藤组、金钱草组、雷公藤配伍金钱草组(配伍组)、单纯应激组、雷公藤应激组、金钱草应激组、配伍应激组。雷公藤组、金钱草组、配伍组分别以2、1、3g/kg的剂量灌胃给药14d,1次/d。通过角叉菜胶炎症模型评价雷公藤、金钱草、雷公藤配伍金钱草在两种状态下的抗炎作用,通过检测小鼠血清相关指标(AST、ALT、BUN、Cr)和肝、肾脂质过氧化指标(T-SOD、MDA),探讨金钱草在两种状态下对雷公藤的减毒作用。结果:雷公藤组、金钱草组、配伍组在风湿热应激前后均使小鼠在角叉菜胶致炎30~90min后足肿胀度显著降低(P<0.05,P<0.01),且配伍组足肿胀度在各自条件下最低,且配伍应激组相对于雷公藤应激组的足肿胀抑制率提高幅度小于配伍组相对于雷公藤组。雷公藤组在风湿热应激前后均使小鼠血清AST、ALT、BUN、Cr水平升高和肝肾T-SOD、MDA水平降低(P<0.01),而配伍组在风湿热应激前后均可逆转这种改变(P<0.05,P<0.01),雷公藤应激组相对于单纯应激组血清和肝肾中各指标的变化率大于雷公藤组相对于角叉菜胶组,而配伍应激组相对于单纯应激组的变化率小于配伍组相对于角叉菜胶组。结论:风湿热应激前后雷公藤配伍金钱草皆具有抗炎增效减毒的作用,其中应激后抗炎增效作用减弱,而减毒作用增强,其配伍减毒体现了中医中"有故无殒"思想,减毒机制可能与抑制肝脂质过氧化并增强抗氧化水平有关。