瘦素特异性小干扰RNA对实验性肝纤维化的影响

目的 研究针对大鼠瘦素基因的小干扰(si)RNA对肝纤维化的治疗效果.方法 将40只雄性SD大鼠平均分为4组,正常对照组皮下注射橄榄油溶液3 ml/kg,2次/周,共6周;肝纤维化模型组皮下注射60% CCl4 3 ml/kg,2次/周,共6周;siRNA治疗组和阴性对照组均于皮下注射60% CCl4 3 ml/kg,2周后尾静脉分别注射siRNA或阴性对照质粒0.2 mg/kg.每周测体质量1次,根据体质量调整药物用量.设计针对瘦素mRNA的siRNA,并构建其表达载体;用脂质体方法通过尾静脉注射转染入CCl4诱导的肝纤维化大鼠体内,然后分别采用逆转录-聚合酶链反应、免疫组织化学方法检测瘦素与Ⅰ、Ⅲ型胶原在肝脏组织中的表达.免疫组织化学资料采用等级资料秩和检验.PCR结果采用单因素方差分析进行统计学处理,P＜0.05时用SNK法进行多重比较.结果 瘦素mRNA在正常对照组组、肝纤维化模型组、siRNA治疗组和阴性对照组的相对表达量分别为0.75±0.03、2.34±0.14、0.90±0.06、2.31±0.13,各组比较,F=797.64,P=0.000,差异有统计学意义;Ⅰ型胶原mRNA在各组的相对表达量分别为1.10±0.11、2.75±0.13、1.27±0.08、2.77±0.12,各组比较,F=695.71,P=0.000,差异有统计学意义;Ⅲ型胶原mRNA在各组的相对表达量分别为0.62±0.07、1.52±0.09、0.85±0.08、1.51±0.07,各组比较,F=371.57,P=0.000,差异有统计学意义.结论 针对瘦素基因的siRNA对肝纤维化有明显的治疗作用.     

Hedgehog通路与肝纤维化及肝星状细胞活化的关系研究

目的:探讨Hedgehog通路与肝纤维化及肝星状细胞(HSC)活化的关系.方法:清洁级SD雄性大鼠20只,均分为模型组和对照组.模型组采用腹腔注射四氯化碳(CCl4)和高脂饮食诱导肝纤维化,对照组予以正常饮食.第8周末取模型组存活大鼠与对照组中大鼠各5只处死,取左叶肝脏组织.HE、Masson染色观察两组肝组织病理变化;逆转录-多聚酶链反应(RT-PCR)检测纤维化大鼠肝脏中表达Hedgehog通路成员超音速Hedgehog信号通路(Shh)、膜受体patched(Ptc)、smoothened(Smo)和核转录因子Gli表达;实时荧光定量PCR法检测Hedgehog通路成员及HSC活化标志基因α-平滑肌肌动蛋白(α-SMA)mRNA在两组大鼠肝脏中的表达差异.体外培养HSC-T6细胞,RT-PCR检测HSC-T6细胞株中Hedgehog通路成员的表达;四甲基偶氮唑盐比色分析(MTT)法检测不同浓度环耙明(Cyclopamine,Cyc)对HSC-T6增殖的影响;分别用0、100/μmol/L的Cye干预HSC-T6,实时荧光定量PCR法检测Shh、Smo、Ptc、Gli-1及αSMA mRNA表达差异.结果:模型组大鼠肝脏有大量脂质及胶原沉积,且肝脏组织中均有Shh、Smo、Ptc、Gli-1表达.荧光定量PCR结果示模型组大鼠Shh、Smo、Gli-1及αSMA mRNA表达均较对照大鼠升高(20.45±3.31、12.78±0.53、10.88±2.41、4.91±2.59比1;P值均<0.05).Cyc在体外对HSC-T6有明显的抑制作用,且抑制作用呈剂量依赖性(F=636.81,P<0.01).荧光定量PCR结果示,用Cyc 100 μmol/L干预的HSC-T6中,Ptc、Smo、Gli-1和αSMA表达量分别为0.20±0.11、0.21±0.08、0.28±0.05和0.27±0.10,与Cyc 0μmol/L干预比较差异均有统计学意义(P值均<0.01).结论:肝纤维化过程中Hedgehog通路成员表达增高,抑制Hedgehog通路可抑制HSC活化,推测Hedgehog通路通过活化HSC促进肝纤维化的发生.     

NADPH氧化酶在瘦素诱导肝星状细胞株HSC-T6产生活性氧中的作用及其机制

目的 研究NADPH氧化酶(NOX)是否参与瘦素诱导肝星状细胞(HSC)产生活性氧(ROS),并探讨其机制. 方法取对数生长期的HSC-T6细胞,随机分为9组:瘦素组、瘦素+ROS生成系统抑制剂[包括氯化二亚苯基碘嗡(DPI)、鱼藤酮、甲双吡丙酮、别嘌呤醇和吲哚美辛]组成的干预组、瘦素+JAK抑制剂AG490组成的干预组、正常对照组和阴性对照组.HSC-T6细胞经药物作用1、12、24 h后,荧光显微镜和(或)流式细胞术观察细胞内二氯荧光素强度来反应ROS水平;分光光度计检测NADPH的吸光度,以NADPH的消耗量表示NOX活性;逆转录聚合酶链反应检测Rac1和p22Phox的mRNA相对表达量.数据分析用单因素方差分析、SNK-q检验或秩和检验,P＜0.05为差异有统计学意义.结果 HSC-T6细胞加入瘦素(100 ng/ml)作用1 h后,荧光强度较正常对照组明显升高(92.91±4.19比27.56±6.27,P＜0.01);DPI(20 μmol/L)和AG490(50 μ mol/L)能抑制ROS的产生,荧光强度值分别为37.35±4.66和53.12±6.63,均低于瘦素组的92.91±4.19(q值分别为31.78和22.76,P值均＜0.01).瘦素作用HSC-T6细胞1 h后,NADPH的消耗量较正常对照组明显升高[(1.90±0.22)pmol·min-1·mg1比(0.76±0.06)pmol·min-1·mg-1,P＜0.05)],而作用12、24 h后的消耗量明显高于1 h时的消耗量(x2值均为7.54,P值均＜0.05);DPI及AG490干预能抑制瘦素诱导NOX活性的上调(q值分别为16.58和16.23,P值均＜0.05).瘦素作用12 h后,HSC-T6细胞内Racl和p22Phox的mRNA相对表达量明显高于正常对照组(分别为0.41±0.13比0.14±0.08和0.45±0.12比0.20±0.08,P值均＜0.05).结论 瘦素诱导HSC产生的ROS主要来源于NOX,其机制可能是瘦素通过JAK信号通路直接激活NOX,并通过上调NOX的亚基表达使NOX活性持续增高而产生大量ROS.     

四氯化碳肝纤维化大鼠肝组织差异蛋白质组的动态变化

目的 探索肝纤维化形成过程中肝组织蛋白质组的变化,部分解析肝纤维化发生、发展的病理生理机制. 方法 采用四氯化碳(CCl4)诱导大鼠肝纤维化模型,应用双向凝胶电泳技术分离大鼠肝组织总蛋白质,经考马斯亮蓝染色、图像分析、识别差异表达的蛋白质点,应用基质辅助激光解吸电离飞行时间串联质谱及数据库查询鉴定差异蛋白质点.采用Western blot、免疫组织化学方法对细胞角蛋白(CK)8、CK18进行蛋白质表达水平的验证.计量资料采用单因素方差分析中的LSD法或非参数检验中的H检验进行统计学分析. 结果 大鼠造模后,随时间的推移,肝纤维化评分逐渐增加(3周组＜6周组＜9周组),建立了正常大鼠和大鼠CCl4肝纤维化形成过程3、6、9周肝组织双向凝胶电泳图谱,质谱鉴定了44种差异蛋白质;采用Western blot、免疫组织化学方法对CK8、CK18的验证结果与双向凝胶电泳结果基本一致.正常组及3、6、9周模型组CK8/CK18蛋白相对表达量分别为:0.113±0.005/0.170±0.030、0.473±0.046/0.530±0.070、0.682±0.087/0.780±0.080、0.837±0.096/1.390±0.130,各组间差异均有统计学意义(F值分别为196.085/74.088、13.870/16.115、75.800/75.900,P值均＜0.01). 结论 CCl4大鼠肝纤维化形成与发展过程中差异表达蛋白质的功能主要涉及细胞生长、发育与分化,细胞增殖与凋亡,血管新生或重构,氧化应激,物质代谢及转运,信号转导等.     

骨形成蛋白7干预肝纤维化小鼠肝组织E3泛素连接酶Arkadia表达的实验研究

目的 探索E3泛素连接酶Arkadia在CCl4所致肝纤维化小鼠肝组织中的动态表达,以及骨形成蛋白7 (BMP-7)对其的阻断作用. 方法 30只健康雄性ICR小鼠,随机分为正常对照组(6只)、模型组(18只)和BMP-7干预组(6只);模型组再按不同的时间点分为4周、8周和12周3个亚组.在小鼠双后肢皮下交替注射60％ CCl4/花生油溶液(5ml/kg),每周2次,共持续12周,制备肝纤维化模型;BMP-7干预组在皮下注射CCl4的同时,从第9周开始腹腔注射BMP-7 (300Pg/g)溶液,隔天1次,共4周.苏木素-伊红(HE)和Masson染色观察肝组织病理变化;RT-PCR、免疫组织化学和Western blot法检测肝组织中Arkadia的mRNA和蛋白质表达量.样本均数比较用单因素方差分析和(或)配对t检验,方差齐时采用LSD -t检验;相关性分析用Pearson直线相关分析法. 结果 成功建立了肝纤维化小鼠模型.模型组Arkadia、Smad7和TGFβ 1的mRNA表达量在纤维化过程中逐渐升高,12周时达高峰(相对表达量分别为1.3434±0.0149、1.2200±0.0093和1.1258±0.0065),BMP-7干预组表达量降低(相对表达量分别为0.9867±0.0169、0.9517±0.0120和0.9029±0.0085),与对照组(相对表达量分别为0.5398±0.0025、0.7467±0.0072和0.6318±0.0041)相比,差异有统计学意义(F值分别为812.801、451.462和998.957,P值均＜0.01);BMP-7干预组Arkadia、Smad7和TGF β1的mRNA表达明显低于12周模型组(t值分别为12.108、18.737和16.364,P值均＜0.01).正常肝组织中Arkadia、Smad7、TGF β1蛋白仅在汇管区少量表达(相对表达量分别为2.1702±0.0518、2.0798±0.0547和2.4515±0.0487),模型组中其表达量逐渐增加(12周的相对表达量分别为3.4198±0.0279、5.4480±0.0565和5.2619±0.0530),主要在汇管区和肝细胞胞质内表达,BMP-7干预后表达量降低(分别为3.1457±0.0424、3.5616±0.0491和3.5282±0.0195),与对照组相比,差异有统计学意义(F值分别为8.399、609.690和900.561,P值均＜0.01);与12周模型组相比,BMP-7干预组Arkadia、Smad7、TGF β1的蛋白质表达量明显降低(t值分别为23.438、11.667和42.889,P值均＜0.01).结论 Arkadia在肝纤维化进展过程中呈上升趋势,BMP-7具有抗肝纤维化作用并可以抑制纤维化过程中Arkadia的表达.     

黄芩素对TGF-β1诱导HSC-T6细胞活化的影响及其机制的研究

目的探讨黄芩素对TGF-β1诱导HSC-T6细胞活化的影响及其作用机制。方法不同浓度黄芩素(125、250、500、1 000 nmol/L)预处理HSC-T6细胞后再加入含TGF-β1(5μg/L)处理细胞48 h。采用MTT法测定其对HSC-T6增殖作用的影响;免疫细胞化学法测定α-平滑肌肌动蛋白(α-SMA)表达;通过分光光度检测HSC-T6内NOX酶的活性;通过免疫荧光染色检测HSC-T6内ROS的生成。结果黄芩素预处理后HSC-T6增殖能力明显减弱,差异有统计学意义(P0.05、0.01,F=37.318),且呈浓度相关性;随着黄芩素浓度的增加,HSC-T6内α-SMA表达逐渐下降,与TGF-β1处理组比较,差异有统计学意义(P0.05);黄芩素预处理后HSC-T6内NOX的活性显著低于TGF-β1处理组,差异有统计学意义(P0.05,F=40.367),而500、1 000 nmol/L黄芩素组NOX的活性比较差异无统计学意义;黄芩素预处理HSC-T6后细胞内ROS表达较TGF-β1刺激组明显下降,差异有统计学意义(P0.05)。结论黄芩素可以抑制由TGF-β1诱导的HSC-T6细胞活化;机制与其抑制HSC-T6细胞内NOX活性,从而降低ROS的产生有关。     

CCl4诱导大鼠肝硬化形成过程中Caspase-12蛋白表达与肝细胞凋亡的相关性

目的:探讨CCl4大鼠肝硬化形成过程中Caspase-12蛋白表达与肝细胞凋亡的相关性.方法:首次CCl4 3 mL/kg sc,以后500 mL/LCCl4橄榄油溶液2 mL/kg sc,2次/wk,共计12wk制备大鼠肝硬化模型.设4 wk、8 wk、12wk 3个时间点,动态观察肝细胞凋亡指数、肝组织Caspase-12免疫组织化学及蛋白表达.结果:模型大鼠4 wk时呈典型的急性肝损伤改变,8 wk时大鼠呈典型的慢性肝损伤肝纤维化的病理改变,12 wk时已形成肝硬化;随着肝损伤加重和肝硬化形成,肝细胞凋亡指数显著增加,模型对照4 wk与正常组、模型对照8wk比较有显著差异(70.4±11.59 vs 9.6±1.14,95.8±10.94,P＜0.01),模型对照12 wk与模型对照8 wk比较有统计学意义(122.8±17.51 vs 95.8±10.94,P＜0.05).Caspase-12蛋白表达亦显著增加,模型对照4 wk与正常组、模型对照8 wk比较有显著差异(0.071±0.014 vs 0.014±0.007,1.172±0.028,P＜0.01),模型对照12wk与模型对照8 wk比较亦有显著差异(1.84±0.083 vs 1.172±0.028,P＜0.01);且肝细胞凋亡指数和Caspase-12蛋白表达量之间呈正相关(r=0.89,t=9.125,P＜0.01).结论:内质网凋亡通路参与CCl4大鼠肝硬化形成过程中肝细胞凋亡事件,其关键的凋亡酶Caspase-12蛋白表达量基本能够反映肝细胞的凋亡程度.     

罗格列酮调控PPARγ/HO-1的表达抑制肝星状细胞增殖

目的探讨罗格列酮(RGZ)对肝星状细胞(HSCs)中过氧化酶体增殖物激活受体γ(PPARγ)及血红素加氧酶-1(HO-1)表达的影响。方法以体外活化的肝星状细胞(HSC-T6)为研究对象,分为:空白对照组、RGZ干预组、RGZ与锌原卟啉-Ⅸ(ZnPP-Ⅸ)共同干预组。采用四甲基偶氮唑盐法检测HSC-T6的增殖情况,酶联免疫吸附试验检测细胞上清液中透明质酸(HA)及Ⅲ型前胶原肽(PⅢP)含量,实时荧光定量PCR、蛋白质印迹法及免疫细胞化学技术检测PPARγ、HO-1的mRNA及蛋白相对表达水平。多组间样本均数的比较采用单因素方差分析,组间比较采用LSD检验。结果RGZ干预组HSC-T6增殖活性及HA、PⅢP表达较空白对照组显著下降(P值均<0.01),但PPARγ、HO-1的mRNA及蛋白相对表达量均较空白对照组显著增加(PPARγ:2.97±0.22对比1.07±0.05,0.96±0.08对比0.31±0.03;HO-1:4.28±0.73对比1.80±0.36,1.83±0.26对比0.61±0.09),P值均<0.01,差异有统计学意义。RGZ与ZnPP-Ⅸ共同干预组同RGZ干预组比较,HSC-T6增殖活性及HA、PⅢP表达有所升高(P值均<0.05);HO-1的的mRNA相对表达量(3.16±0.38对比4.28±0.73)和蛋白相对表达水平(1.31±0.17对比1.83±0.26)降低,P值均<0.05,差异有统计学意义;PPARγ的mRNA及蛋白相对表达量比较,差异无统计学意义(P值均>0.05),但呈下降趋势。RGZ与ZnPP-Ⅸ共同干预组与空白对照组HO-1的mRNA相对表达量(1.80±0.36)及蛋白相对表达量(0.61±0.09)比较,明显增高,P值均<0.05。免疫细胞化学染色同上述结果一致。结论罗格列酮诱导PPARγ表达增加进而抑制HSC增殖活化及胶原产生的作用可能是通过调控其下游HO-1的表达而实现的。     

四氯化碳诱导的肝纤维化小鼠肝组织和HSC-T6细胞NOX4基因及其蛋白表达的变化

目的 探讨四氯化碳(CCl₄)诱导的肝纤维化小鼠和肝星状细胞(HSC-T6)还原型辅酶烟酰胺腺嘌呤二核苷酸磷酸氧化酶家族氧化酶4(NOX4)基因及其蛋白表达的变化。方法 采用腹腔注射四氯化碳(CCl₄)构建10只小鼠肝纤维化模型,采用qRT-PCR法和Western Blot法检测小鼠肝组织NOX4基因和蛋白表达水平。将肝星状细胞(HSC-T6)分为对照组、无意干预组和NOX4-siRNA干预组,后两组分别采用脂质体2000将无意义序列或NOX4-siRNA转染HSC-T6细胞,采用qRT-PCR法和Western Blot法检测HSC-T6细胞NOX4、α平滑肌肌动蛋白(α-SMA)、I 型胶原(Col1a I)、组织金属蛋白酶抑制剂1(TIMP-1)、金属蛋白酶2(MMP-2)、转化生长因子 β1(TGF-β1)、Smad2和Smad3水平,采用DCFH-DA荧光探针法检测细胞活性氧(ROS)含量,采用MTT法检测细胞增殖,使用流式细胞术检测细胞周期和凋亡情况。结果 模型小鼠肝组织出现明显的病理学损伤,有大量的胶原纤维沉积;模型组小鼠肝组织NOX4 mRNA水平显著高于对照组(P＜0.05);与对照组细胞比,NOX4-siRNA干预组细胞NOX4 mRNA及其蛋白、ROS、增殖活性、S期细胞比例、α-SMA、Col1a I、TIMP-1、MMP-2、TGF-β1、p-Smad2/Smad2、p-Smad3/Smad3表达水平显著降低,而G0/G1期细胞比例和细胞凋亡率显著升高(P＜0.05)。结论 肝纤维化组织NOX4呈高水平,下调NOX4可抑制肝星状细胞的增殖和活化,并促进其凋亡,可能是通过下调TGF-β/Smad信号通路实现的。     

水飞蓟素改善棕榈酸引起的胰岛素抵抗及机制初步探讨

目的评价水飞蓟素(Sil)对棕榈酸(PA)诱导HepG2细胞IR的作用并进一步揭示其机制。方法实验分为正常对照(NC)组,棕榈酸(PA)组,Sil干预低剂量(12.5μmol/L,L-Sil)组、中剂量(25μmol/L,M-Sil)组和高剂量(50μmol/L,H-Sil)组。PA诱导HepG2细胞IR,分别给予12.5,25,50μmol/L Sil作用6 h,测定葡萄糖消耗量,使用活性氧簇(ROS)试剂盒测定ROS活性水平。采用Western blot方法检测AKT以及还原型烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶的NOX2、p67phox、p47phox蛋白表达水平。结果PA组与NC组比较,葡萄糖耗氧量降低[(41.2±6.1)%vs(100±12)%,P=0.0087],磷酸化AKT(p-AKT)蛋白表达量降低[(0.458±0.185)vs(1.00±0.13),P=0.0184],同时PA组ROS水平[(1567±189 vs(14±34)U/ml,P=0.0094]以及NAPDH氧化酶NOX2、p67、p47亚基的表达水平升高(P0.05)。Sil各组与PA组比较可增加葡萄糖消耗量[(52.8±8.4)%vs(62.2±6.5)%vs(82.3±9.8)%],差异有统计学意义(P=0.041、0.039、0.0076);H-Sil组磷酸化AKT(p-AKT)蛋白表达量提高(0.793±0.249),与PA组比较,差异有统计学意义(P=0.0395);Sil可降低ROS水平[(1085±252)vs(851±184)vvs(405±35)],与PA组比较,差异有统计学意义(P=0.047、0.023、0.0015),以及降低NAPDH氧化酶NOX2、p67、p47亚基的表达水平(P0.05),且作用强度随Sil剂量的增加而增强。结论Sil可能通过降低NADPH氧化酶活性降低氧化应激,从而改善HepG2细胞的IR。     

The immunoneuroendocrine role of melatonin

Abstract: A tight, physiological link between the pineal gland and the immune system is emerging from a series of experimental studies. This link might reflect the evolutionary connection between self-recognition and reproduction. Pinealectomy or other experimental methods which inhibit melatonin synthesis and secretion induce a state of immunodepression which is counteracted by melatonin. In general, melatonin seems to have an immunoenhancing effect that is particularly apparent in immunodepressive states. The negative effect of acute stress or immunosuppressive pharmacological treatments on various immune parameters are counteracted by melatonin. It seems important to note that one of the main targets of melatonin is the thymus, i.e., the central organ of the immune system. The clinical use of melatonin as an immunotherapeutic agent seems promising in primary and secondary immunodeficiencies as well as in cancer immunotherapy. The immunoenhancing action of melatonin seems to be mediated by T-helper cell-derived opioid peptides as well as by lymphokines and, perhaps, by pituitary hormones. Melatonin-induced-immuno-opioids (MHO) and lymphokines imply the presence of specific binding sites or melatonin receptors on cells of the immune system. On the other hand, lymphokines such as -γ-interferon and interleukin-2 as well as thymic hormones can modulate the synthesis of melatonin in the pineal gland. The pineal gland might thus be viewed as the crux of a sophisticated immunoneuroendocrine network which functions as an unconscious, diffuse sensory organ.     

Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland

Abstract: The abundance of gap junctions between rat pineal astrocytes formed by connexin43 (Cx43) was studied during development. Levels and distribution of Cx43 were measured by immunoblotting and indirect immunofluorescence, respectively. The amount of Cx43 in cells located within the gland was low until about the 7th postnatal day and increased to adult values between the 14th and 21st days postpartum. Although astrocytes, recognized by their vimentin immunoreactivity, were scarce before birth, they were abundant by the 7th postnatal day suggesting that the low levels of Cx43 found at this age corresponded to a low expression of this protein. Localization of the immunoreactivity to Cx43 and vimentin showed a close correlation, indicating that mature or immature pineal astrocytes form gap junctions made of Cx43. Since Cx43 levels attained their adult values at about the time the innervation and the functional state of the gland reached maturity (2–3 weeks after birth), it is proposed that astrocyte gap junctions are involved in the function of the adult rat pineal gland.     

Response of rat pineal melatonin to calcium, magnesium, and lithium is circadian stage dependent

Abstract: Herein we documented the response of pineal melatonin production to electrolytes known to be effective on pineal function in view of a possible circadian stage dependence. We studied the release of melatonin by perifused rat pineal glands at 2 different circadian stages corresponding to the middle of the light and dark periods, i.e., respectively, 7 and 19 HALO (Hours After Light Onset, L:D = 12:12). The initial efflux rates were, as expected, much higher in the perifusates of glands removed from rats sacrificed during the dark phase than of those removed during the light phase. After 3 hr of perifusion, melatonin release reached similar levels which were found constant up to the 8th hr of perifusion, whatever the circadian stage. Perifusion of the glands with physiological concentrations for the rat of calcium (5.2 mmol/1) and magnesium (1.34 mmol/1) resulted in a stimulatory effect on the pineal glands removed from rats sacrificed in the middle of the dark period (19 HALO), whereas no effects were observed on the pineal glands removed from rats sacrificed during the light (7 HALO). Lithium (0.28 and 0.55 mmol/1) was ineffective on melatonin release in pineal glands removed 7 and 19 HALO. Our results show differences in the initial efflux rates of melatonin and in the response of perifused pineal glands to calcium and magnesium according to the circadian stage.     

Conservative management of perforated duodenal diverticulum： A case report and review of the literature

Duodenal diverticula are a relatively common condition. They are asymptomatic, unless they become complicated, with perforation being the rarest but most severe complication. Surgical treatment is the most frequently performed approach. We report the case of a patient with a perforated duodenal diverticulum, which was diagnosed early and treated conservatively with antibiotics and percutaneous drainage of secondary retroperitoneal abscesses. We suggest this method could be an acceptable option for the management of similar cases, provided that the patient is in good general condition and without septic signs.     

Presence of immunoreactive growth hormone and prolactin in the ovine pineal gland

Abstract: The use of antisera raised against bovine growth hormone (GH) and ovine prolactin (PRL) enabled the detection of related immunoreactive (ir) sequences of proteins in ovine pineal tissue. The isolation of PRL-like ir-material was accomplished using a 0.25 M ammonium sulphate (pH 5.5) extraction followed by ethanol precipitation, whereas the resulting 2.0 M ammonium sulphate (pH 7.0) precipitate contained a GH-like immunoreactivity. Gel chromatography of the GH-like immunoreactivity (Sephadex G-100) indicated the presence of several GH-like fragments ranging in the M_r range of 7,000 to 55,000. Analyses of the PRL-like ir-material found in pineal tissue on HPLC using a TSK 545-DEAE column led to the resolution into a single peak of immunoreactivity. A single peak of activity was also observed following chromatofocusing and hydrophobic interaction chromatography of the ir-peak from the TSK 545-DEAE column. The PRL-like ir-material inhibited the binding of [¹²⁵I]ovine PRL-S14 to anti-ovine PRL antibodies without showing an affinity for binding to anti-rat PRL or anti-bovine GH antibodies. Scatchard analysis of the binding of pineal PRL-like ir-material and pituitary ovine PRL-S14 to liver membranes from day-20 pregnant rats revealed similar affinity constants (K_a of 4.7 ± 0.2 × 10⁹ M^-1). In addition, the replication of Nb 2 Node rat lymphoma cells was stimulated by pineal PRL-like ir-material, an effect known to be specific for lactogenic hormones. The pineal PRL-like immunoreactivity appeared on sodium dodecyl sulfate polyacrylamide gels as a single major band of M_r 24,000. The functional status of PRL-and GH-like ir-material in the ovine pineal remains to be determined, but evidence is presented that the overall protein synthesis rate of the rat pineal responded to circulating concentrations of PRL.     

Microbiology of human immunodeficiency virus anorectal disease

PURPOSE: Individuals who are seropositive for the human immunodeficiency virus are at high risk for opportunistic infection and anorectal disorders. Little prospective information is available regarding anorectal pathogens in these patients. METHODS: One hundred sixty-three HIV-seropositive patients presented to the colorectal clinic between 1989 and 1992. Forty-seven (29 percent) patients were thought to have an infectious process and were prospectively studied using a standardized multiculture protocol. RESULTS: Mean age was 33 (range, 19–59) years. All were male; high-risk behavior accounted for 87 percent of HIV transmissions. Presenting complaints included anorectal pain (79 percent), pus per anum (28 percent), and blood per anum (26 percent). Examination revealed perianal tenderness (60 percent), condyloma (38 percent), perianal ulcers (38 percent), and anal fissures (34 percent). Sixty-six sets of cultures were performed; 28 patients had one set, 15 had two sets, and 4 had three sets. Thirty-two of these 47 patients (68 percent) had positive cultures including herpes (50 percent), cytomegalovirus (25 percent),Neisseria gonorrhoeae (16 percent), chlamydia (16 percent), acidfast bacilli (2 percent), and others (9 percent). Six of 32 patients with positive cultures had more than one organism cultured. Sixteen (50 percent) patients with positive cultures were treated medically, 8 (25 percent) were treated surgically and 8 (25 percent) were treated with both modalities. Sixty-one procedures were performed on 17 patients for condylomata. Eighteen patients had 20 procedures for abscesses, 50 percent of whom had positive cultures for other than common bowel flora; all improved. Fourteen patients underwent 33 procedures for perianal fistulas.Mycobacterium fortuitum was cultured from one patient who required 13 procedures for abscesses and fistulas. Forty-five (96 percent) patients were followed for an average of 12.5 months ±2.9 SEM (range, 1–94 months). Symptoms were improved or resolved in 22 of 32 (69 percent) patients with positive cultures and in 11 of 13 (84 percent) with negative cultures. CONCLUSIONS: Specific pathogens may often be identified in human immunodeficiency virus-seropositive patients with anorectal disorders if aggressively sought. Although patients without specific pathogens identified may be expected to improve with planned empiric treatment, positive identification allows more directed therapy.