Polymyxin B,a selective inhibitor of protein kinase C,diminishes the release of noradrenaline and the enhancement of release caused by phorbol 12,13-dibutyrate

Summary Slices of the rabbit hippocampus were labelled with ³H-noradrenaline, superfused continuously with a modified Krebs-Henseleit medium containing the uptake inhibitor cocaine and stimulated electrically (2 ms, 3 Hz, 24 mA, 5 V/cm). Phorbol 12,13-dibutyrate (PDB), a potent activator of protein kinase C (PKC), strongly enhanced the electrically-evoked overflow of tritium. In contrast, polymyxin B, a relatively selective inhibitor of PKC, diminished the evoked tritium overflow in a time-and concentration-dependent manner. The enhancement of the evoked overflow of tritium caused by PDB was strongly reduced in the presence of polymyxin B (100 mol/l). These results suggest 1. that PKC may be involved in the physiological mechanism of action-potential-induced noradrenaline release from noradrenergic nerve terminals and 2. that the PDB-induced enhancement of noradrenaline release may be due to a direct activation of PKC.Abbreviations PKC protein kinase C - PDB phorbol 12,13-dibutyrate - TPA 12-O-tetradecanoyl 13-acetate     

A novel adipokine WISP1 attenuates lipopolysaccharide-induced cell injury in 3T3-L1 adipocytes by regulating the PI3K/Akt pathway

BackgroundTo study the effect of WISP1 on lipopolysaccharide (LPS)-induced cell injury in 3T3-L1 adipocytes.MethodLentivirus was transiently transfected into log phase 3T3-L1 adipocytes, which were then treated with LPS at a concentration of 10 μg/mL for 24 h. The cells were divided into the following groups: group A (control, untreated cells); group B (LPS-treated cells); group C (GFP), cells transfected with lentivirus-containing GFP; group D (GFP+LPS), group C treated with LPS;group E (WISP1OE), cells transfected with lentivirus, group F (shNC+LPS), cells transfected with lentivirus-containing nshRNA treated with LPS; group G (shWISP1 +LPS), cells transfected with lentivirus-containing shRNA treated with LPS; group H (WISP1OE+LPS), group E treated with LPS; group I (WISP1OE+LPS+LY294002), group E treated with LPS followed by LY294002 for 24 h.ResultsWISP1 overexpression notably ameliorated cell apoptosis, accompanied with the increased expression of bcl-2, the decreased expressions of bax and cleaved-caspase-3, and promoted the release of inflammatory factors, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in LPS-treated 3T3-L1 adipocytes. WISP1 knockdown exhibited the opposite results. In addition, WISP1 stimulated Akt phosphorylation and reduced nuclear translocation of Fork head box protein O3 (FoxO3a) in 3T3-L1 adipocytes treated by LPS. The inhibition of the PI3K/Akt signaling pathway diminished the protective effect of WISP1.ConclusionWISP1 prevents 3T3-L1 adipocytes from being injured by LPS by regulating the PI3K/Akt pathway.     

术前孤立性CRP升高与体外循环术后并发症的相关性

目的探讨无感染的、术前孤立性C-反应蛋白(CRP)增加,对于体外循环心脏术后的结果,是否有预测性价值。方法分术前孤立性CRP升高(10.5～70.2mg／L)50例(A组)与CRP正常(＜10mg／L)50例对照(B组),B组匹配A组在年龄、性别和疾病种类,两组均进行体外循环心脏手术。结果A组脓毒性并发症(20％)比对照组(2％)多(P＜0.01)。这些病人微生物学阳性仅10％。A组中需要儿茶酚胺支持的占28％,而B组仅12％(P＜0.05)。A组较B组术后需呼吸机支持的时间明显延长(25.2±6.2h比6.6±0.5h)(P＜0.01)、ICU滞留时间也较B组长(4.6±0.8d比2.6±0.3d)(P＜0.05)。结论术前孤立性CRP升高的病人,体外循环术后,发生脓毒性并发症的可能性明显增加。且大多数病例微生物学实验阴性,推测大多数脓毒性并发症是由于全身炎症反应综合征的原因。     

白细胞进入腹腔是引起蛋白质经腹腔丢失的关键

目的为了研究细菌性腹膜炎时经腹腔蛋白质丢失的机制,阐明白细胞移行与蛋白质丢失的关系。方法给兔腹腔内注射大肠杆菌(E.coil)4×106CFU+生理盐水(35ml/kg),做成急性腹膜炎动物模型。通过测定实验6或8h期间腹透液中白细胞总数(WBC)及中性粒细胞(PMNs)计数情况以及腹膜对蛋白质的通透性(蛋白质D/P比值)。设立了两个系列的实验系列一,应用氮介(mustine),1.2mg/kg,实验前3天静脉注射,以耗尽循环血中的白细胞;系列二,用单克隆抗体(mAb)60.32mg/kg,实验前5min静脉注射,以阻滞PMNs上的粘附分子CD18,从而抑制PMNs向腹腔移行。同时设立了阳性对照组(即腹膜炎组)及阴性对照组(无腹膜炎组)。结果系列一中mustine降低87%循环血中白细胞及93%循环血中PMNs,此时即使腹腔内注射细菌,白细胞向腹腔的移行及腹腔蛋白质的渗出均较未注射mustine的腹膜炎组明显降低,而与无腹膜炎的正常对照组结果相似。系列二,静脉注射mAb60.3同样也明显降低白细胞及PMNs向腹腔的移行及经腹腔蛋白质的丢失。结论急性细菌性腹膜炎时白细胞向腹腔移行导致了经腹腔蛋白质的丢失。     

天麻素对缺血再灌注损伤星形胶质细胞的保护作用及其对一氧化氮合成酶活性的影响

观察天麻素对脑缺血再灌注损伤星形胶质细胞胶原纤维酸性蛋白 (GFAP)表达、乳酸脱氢酶(LDH)漏出量以及一氧化氮合成酶 (NOS)活性的影响。结果 :天麻素大、小剂量组GFAP纤维样改变减轻 ,强阳性反应细胞数减少 ;LDH漏出量下降 ;NOS活性减弱。提示 :天麻素对模拟脑缺血再灌注损伤星形胶质细胞有良好的保护作用 ,其途径之一可能是通过抑制NOS活性的反应性增强来实现的。     

膀胱癌P21、P53、nm23蛋白表达的临床意义

目的探讨癌基因与抑癌基因表达与膀胱癌生物学行为的关系.方法应用免疫组化方法对48例膀胱移行细胞癌中P21、P53、nm23蛋白进行检测.结果P21、P53、nm23蛋白表达的阳性率分别是58.3%、47.9%、41.7%.P21、P53蛋白表达阳性率与肿瘤分级、分期及复发呈正相关.nm23蛋白表达阳性率与分级呈正相关,与分期及复发呈负相关.77.1%膀胱癌有上述蛋白异常表达,其中47.9%膀胱癌同时有两个或两个以上蛋白表达.结论癌基因及抑癌基因的异常表达及协同作用,在膀胱癌发生、发展中起重要作用.     

电针结合有氧运动对自然衰老大鼠骨骼肌IGF-I/Akt通路的作用

目的:探索低频电针结合有氧运动对增龄性骨骼肌萎缩的效应,以及IGF-I/Akt及其下游蛋白质合成相关通路信号蛋白的影响。方法:以自然衰老SD大鼠为研究对象,将6月龄雄性SD大鼠32只,体重400～450 g,饲养至大鼠12月龄,根据体重随机分为4组。对照组(YC,只抓取、固定、放回,不做其他干预),电针组(YA,电针干预),运动组(YE,运动干预),电针+运动组(YEA,电针结合运动干预),自SD大鼠12月龄开始持续干预至18月龄,实验结束时观察各组自然衰老大鼠:骨骼肌湿重/体重比;光学显微镜下比目鱼肌HE染色形态;Real-time qPCR法检测骨骼肌中IGF-I mRNA的表达水平;Western印迹法测定的大鼠腓肠肌中AKT、mTOR、p70S6K和p-p70S6K相关蛋白表达情况。结果:与YC组相比,YA组、YEA组皆明显增加18月龄大鼠腓肠肌湿重/体重比(P0.05);YEA组能明显增加比目鱼肌湿重/体重比,高于YC组和YA组(P0.05)。与YC组相比,各个干预组大鼠的腓肠肌IGF-I mRNA表达水平皆有上升趋势,其中YEA组IGF-I mRNA表达增加更为明显(P=0.051)。与YC组相比,电针组(YA)p-Akt,p-mTOR表达升高(P0.05),电针+运动组(YEA)p-Akt,p-mTOR,p-p70S6K表达也显示出升高趋势(P0.05)。结论:电针结合有氧运动可延缓18月龄自然衰老大鼠增龄性骨骼肌萎缩,其分子机制可能与通过激活IGF-I/Akt通路,促进蛋白合成有关。