乙醇对脑缺血再灌注大鼠海马凋亡诱导因子和胱天蛋白酶-3表达的影响

目的 探讨乙醇对脑缺血再灌注大鼠海马区凋亡诱导因子(apoptosis inducing factor,AIF)和胱天蛋白酶-3表达的影响.方法 68只健康成年雄性Wistar大鼠,随机分为假手术组(4只)、生理盐水对照组以及小剂量(1.0 g/kg)、中剂量(1.5 g/kg)和大剂量(2.0g/kg)乙醇组,生理盐水对照组和各剂量乙醇组再分别按干预时间点分为缺血再灌注0h、1h、2h和3h亚组(每组4只).采用线栓法建立大鼠大脑中动脉缺血再灌注模型.各剂量乙醇组和生理盐水对照组在缺血2h再灌注0h、1h、2h和3h时腹腔注射相应剂量乙醇或等体积生理盐水.脑缺血2h再灌注24 h时采用行为学评分评价大鼠神经功能缺损.采用免疫组织化学法检测脑缺血2h再灌注24h时缺血侧海马区AIF和胱天蛋白酶-3表达.结果 行为学评价显示,假手术组神经功能缺损评分均为0分;不同剂量乙醇组神经功能缺损评分均显著性低于相同干预时间点的生理盐水对照组(P均=0.000),且不同剂量乙醇组相同干预时间点之间均存在显著性差异(P均=0.000),大剂量乙醇组均最低;相同剂量乙醇组不同干预时间点之间无显著性差异(P均＞0.05).免疫组织化学显示,假手术组AIF和胱天蛋白酶-3阳性细胞数量分别为(17.21 ±2.86)个和(20.60 ±4.39)个,均显著性少于缺血再灌注0h时的生理盐水对照组和各剂量乙醇组(P均=0.000);不同剂量乙醇组海马区AIF和胱天蛋白酶-3阳性细胞数量均显著性少于相同干预时间点的生理盐水对照组(P均=0.000),且不同剂量乙醇组相同干预时间点之间均存在显著性差异(P均=0.000),大剂量乙醇组均最少;相同剂量乙醇组不同干预时间点之间均无显著性差异(P均＞0.05).结论 乙醇对脑缺血再灌注损伤大鼠脑组织具有保护作用,其机制可能与抑制AIF和胱天蛋白酶-3表达有关.     

丁苯酞通过增强抗氧化活性保护局灶性脑缺血再灌注大鼠

目的 探讨丁苯酞对脑缺血再灌注损伤的保护作用和可能机制.方法 60只健康清洁级成年Sprague-Dawley大鼠,随机分为假手术组、生理盐水对照组、小剂量丁苯酞组和大剂量丁苯酞组,每组15只.应用线栓法建立局灶性脑缺血再灌注模型.再灌注开始时,小剂量丁苯酞组和大剂量丁苯酞组分别腹腔注射丁苯酞注射液100 mg/k和400 mg/kg,假手术组和生理盐水组分别腹腔注射生理盐水0.5 ml/kg.所有大鼠在缺血再灌注24h后处死.结果 小剂量丁苯酞组(t=1.488,P=0.000)和大剂量丁苯酞组(=2.362,P=0.000)神经功能缺损程度较生理盐水组均显著性改善,其中大剂量丁苯酞组较小剂量丁苯酞组改善更为显著(t=-0.873,P=0.000).小剂量丁苯酞组(t=18.589,P=0.000)和大剂量丁苯酞组(=36.963,P=0.000)脑梗死体积较生理盐水对照组显著性缩小,其中大剂量丁苯酞组梗死体积较小剂量丁苯酞组缩小更显著(t=-18.374,P=0.000).HE染色显示,生理盐水对照组神经元稀疏、大量变性坏死,细胞间隙增大,细胞间质空泡样改变.丁苯酞组神经元变性坏死明显减少,存活神经细胞增多,大剂量丁苯酞组改善更为显著.小剂量丁苯酞组和大剂量丁苯酞组SOD活性较假手术组和生理盐水对照组显著性增高(P均＜0.05),其中大剂量丁苯酞组SOD活性显著性高于小剂量丁苯酞组(t=80.199,P=0.000);小剂量丁苯酞组和大剂量丁苯酞组MDA水平较假手术组和生理盐水对照组显著性降低(P均＜0.05),其中大剂量丁苯酞组MDA水平显著性低于小剂量丁苯酞组(t=-1.308,P=0.000).结论 丁苯酞对缺血再灌注损伤的保护作用可能与机体抗氧化活性增强有关.     

自体骨髓来源内皮祖细胞移植改善脑缺血再灌注大鼠神经功能转归

目的 探讨目体骨髓米源内皮祖细肥(endothehalprogenitor cell,EPC)移植对脑缺血大鼠神经功能转归的影响及其可能机制.方法 体外分离培养自体骨髓来源EPC并用5-溴脱氧尿嘧啶核苷(5 -bromodeoxyuridine,BrdU)标记.线栓法制作大鼠大脑中动脉闭塞(middle cerebral arteryocclusion,MCAO)模型.EPC组大鼠经颈外静脉移植自体EPC[ 106/ml·kg)],对照组注射磷酸盐缓冲液(1 ml/kg),假手术组不进行任何处理(n=15).改良神经功能缺损严重程度评分(modifiedneurological severity score,mNSS)观察大鼠神经功能变化情况.BrdU免疫组化染色评价EPC增殖和分化.三维共聚焦图像分析检测脑缺血区血管结构和密度.TUNEL染色检测缺血脑组织凋亡细胞.酶联免疫吸附法检测血浆血管内皮生长因子(vascular endothelial growth factor,VEGF)浓度.结果 EPC组mNSS评分显著低于对照组[第8天时;(6.43±0.69)分对(8.86±0.95)分;q=2.673,P=0.035;第14天时:(4.55±0.89)分对(6.73±1.06)分;q=5.360,P=0.035].EPC组BrdU阳性细胞数量显著多于对照组[(42.2±5.76)对(25.67±5.49);q=4.020,P=0.030].EPC组毛细血管直径显著小于对照组[(4.51±0.21)μm对(6.34±0.24) μm;q=3.980,P =0.003];血管密度[(212.64±8.02)/0.002 mm3对(153.60±7.21 )/0.002 mn3;q =9.670,P=0.001]和微血管总表面积[(92 013±5 132)μm3/0.002 mm3对(71 366±4 538) μm2/0.002 mm3;q=4.180,P=0.014]显著高于和大于对照组;EPC组凋亡细胞数量显著少于对照组[(36.26±6.91)对(78.34±7.21);t=-4.834,P=0.003];EPC组血浆VEGF浓度显著高于对照组[(54.91±5.71)pg/ml对(13.81±4.25)pg/ml;q=12.300,P=0.002].结论 自体EPC移植对大鼠缺血脑组织具有保护作用,可能与VEGF相关联的血管再生和神经保护有关,其在治疗缺血性脑血管病中具有重要的应用前景.     

缺血预处理通过减轻内质网应激保护全脑缺血大鼠

目的 探讨抑制内质网应激(endoplasmic reticulum stress,ERS)在缺血预处理诱导脑缺血耐受中的作用.方法 120只成年雄性Sprague-Dawley大鼠,随机分为假手术组、全脑缺血组和缺血预处理组(缺血预处理3min,2d后全脑缺血15 min),设1、3和7d共3个时间点.应用Sugawara法观察大鼠行为学变化,TUNEL染色观察皮质神经元凋亡情况,免疫荧光染色和蛋白质印迹分析检测ERS相关蛋白CHOP、GRP78和胱天蛋白酶-12表达情况.结果 神经行为学评分显示,假手术组无神经功能缺损,全脑缺血组和缺血预处理组均出现明显的神经功能缺损,而且随着时间推移出现逐步改善,但全脑缺血组在模型制作后各时间点的神经功能评分均显著性低于缺血预处理组:1d时:(11.00±0.63)分对(14.33±0.33)分(t=21.74,P=0.001);3d时:(12.17±0.31)分对(15.17±0.48)分(t=27.93,P=0.000);7d时:(14.67±0.49)分对(16.33±0.33)分(t=7.81,P=0.020).TUNEL染色显示,缺血后7 d时,假手术组、全脑缺血组和缺血预处理组每mm2TUNEL染色阳性细胞计数分别为(4.83±1.85)个、(395.67 ±43.43)个和(146.17±27.38)个(F=23.62,P=0.001),缺血预处理组显著性低于全脑缺血组(P=0.001).免疫荧光染色显示,缺血后7d时,缺血预处理组CHOP [(26.50 ± 3.89)个对(82.33±4.25)个;P=0.000]、GRP78[(15.00±2.02)对(35.67±2.99)个;P=0.000]和胱天蛋白酶-12[(22.33 ±2.76)个对(66.50±7.25)个;P=0.000]阳性细胞数量均显著性少于全脑缺血组.蛋白质印迹法显示,缺血后7d时,缺血预处理组CHOP[(1.22±0.38)对(3.22 ±0.51);t=24.50,P=0.001]、GRP78[(1.78±0.45)对(3.16±0.76);t=14.29,P=0.005]和胱天蛋白酶-12[(2.89 ±0.53)对(5.96±0.67);t =77.73;P =0.000]表达显著性低于全脑缺血组.结论 缺血预处理对第2次致死性缺血表现出神经保护作用,其机制可能与ERS减轻,ERS相关蛋白表达下调有关.     

组织型激肽释放酶对脑缺血再灌注大鼠缺血脑组织缓激肽及其受体表达的影响

目的 探讨组织型激肽释放酶(tissue kallikrein,TK)对脑缺血再灌注大鼠缺血脑组织缓激肽、缓激肽B1受体(bradykinin B1 rgceptor,B1R)和缓激肽B2受体(bradykinin B2 receptor,B2R)表达的影响.方法 54只SD大鼠随机分为3组,每组18只.3组分别为假手术组;生理盐水(normal saline,NS)处理组(Ns组):NS 2 ml/(kg·d),连用3 d;TK(处理组(TK组):TK 17.5×10-3U/(kg·d),连用3 d.3 d后分别进行神经功能缺损评分、脑梗死体积测定.酶联免疫吸附法检测缺血区缓激肽含量;采用逆转录聚合酶链反应和Western印迹法分别检测缺血脑组织B1R、B2R mRNA和蛋白表达.结果 与NS组比较,TK组神经功能缺损显著减轻[(6.17±1.17)分对(8.17 4±1.33)分,t=2.000,P=0.004],脑梗死体积明显缩小[(29.67±3.78)%对(37.50±6.72)%,t=0.078,P=0.005];缺血脑组织缓激肽含量升高[(9.25 4±1.13)对(15.53±1.68),t=6.283,P:0.000];B2RmRNA表达显著上调[(1.21±0.17)对(2.15±0.20),t=0.943,P=0.000),而B1R mRNA表达上调不明显[(0.51±0.05)对(0.57±0.06),t=0.058,P=0.141)];B2R蛋白表达显著上调[(1.15±0.16)对(1.88 4±0.21),t=0.737,P=0.0001,B1R蛋白表达上调不明显[(0.50±0.04)对(0.53±0.05),t=1.326,P=0.214].结论 TK 对脑缺血再灌注大鼠具有保护作用,能使缺血脑组织缓激肽含量增高,B2R表达上调,而对B1R表达影响不大.由此推测,B2R在TK保护缺血脑组织中发挥着主要作用.     

阿托伐他汀对大鼠脑出血后血肿周围组织细胞凋亡和细胞色素c表达的影响

目的 探讨阿托伐他汀对大鼠脑出血后血肿周围组织细胞凋亡和细胞色素c(Cytochrome c,CytC)表达的影响.方法 108只雄性Sprague-Dawley大鼠随机分为假手术组、生理盐水对照组和阿托伐他汀组(每组36只),各组再分为6h、12 h、ld、3d、5d和7d时间点(每个时间点6只).采用改良二次注血法制作脑出血模型.阿托伐他汀组在模型制作后给予阿托伐他汀灌胃(20 mg/kg,1次/d),生理盐水对照组给予等体积生理盐水.采用行为学评价进行神经功能评分,TUNEL染色法检测血肿周围细胞凋亡,免疫组织化学法检测血肿周围组织CytC表达.结果 行为学评价显示,阿托伐他汀组和生理盐水对照组神经功能评分均随着时间的推移而逐渐下降,6h、12 h、1d和3d时无显著性差异,但5 d[(0.50±0.55)分对(1.50±0.55)分;t=3.162,P=0.010]和7d[(0.17±0.41)分对(1.00±0.63)分;t=2.712,P =0.022]时阿托伐他汀组神经功能评分显著性低于生理盐水对照组.TUNEL染色法显示,生理盐水对照组与阿托伐他汀组凋亡细胞数量均先增加后减少,高峰出现在模型制作后1d时.各组间相同时间点血肿周围凋亡细胞数量均存在显著性差异(P均=0.000),且生理盐水对照组显著性多于假手术组和阿托伐他汀组(P均＜0.05),但在7d时阿托伐他汀组凋亡细胞数量与假手术组无显著性差异[(12.69±3.35)个对(9.33 ±2.07)个;P=0.148].免疫组织化学法显示,生理盐水对照组与阿托伐他汀组CytC阳性细胞数量均先增加后减少,生理盐水对照组高峰出现在模型制作后12h时[(68.19±11.93)个],而阿托伐他汀组出现在模型制作后ld时[(35.64±9.12)个].各组间相同时间点血肿周围CytC阳性细胞数量均存在显著性差异(P均=0.000),且生理盐水对照组显著性多于假手术组和阿托伐他汀组(P均＜0.05),但在7d时阿托伐他汀组CytC阳性细胞数量与假手术组无显著性差异[(16.08±3.80)个对(13.67±2.94)个;P=0.349].结论 阿托伐他汀可抑制脑出血后血肿周围神经细胞CytC释放,从而抑制CytC介导的细胞凋亡,减轻脑出血后脑神经功能缺损.     

抑制可溶性环氧物酶对局灶性脑缺血再灌注大鼠的神经保护作用

目的 探讨可溶性环氧物酶(soluble epoxide hydrolase,sEH)抑制剂12-(3-金刚烷-1-基脲基)-十二烷酸[12-(3-adamant an-1-yl-ureido)-dodec-anoic acid,AUDA]对局灶性脑缺血再灌注大鼠的神经保护作用和机制.方法 60只雄性Sprague-Dawley大鼠随机分为假手术组、生理盐水对照组以及小剂量(0.157 ml/kg)、中剂量(0.235 ml/kg)和大剂量(0.314 ml/kg) AUDA处理组(每组12只),各组随机取4只大鼠分别用于梗死体积、细胞凋亡和p-Akt免疫组织化学检测.线栓法建立大脑中动脉闭塞再灌注模型.各AUDA处理组和生理盐水对照组均在再灌注前分别经腹腔给予相应剂量的AUDA或等体积生理盐水.再灌注24 h时进行神经功能缺损评分.2,3,5-氯化三苯基四氮唑染色法检测脑梗死体积.原位缺口末端标记法(TdT-mediated dUTP nick end labeling,TUNEL)检测梗死周围区脑组织细胞凋亡.免疫组织化学法检测梗死周围区脑组织p-Akt表达.结果 TTC染色显示,假手术组未见梗死.生理盐水对照组以及小剂量、中剂量和大剂量AUDA组梗死体积分别为(254.146±25.481)、(212.679±7.514)、(150.188±33.997)和(99.563±3.415) mm3,存在显著性差异(F=39.637,P=0.000).各剂量AUDA组均显著性小于对照组(P均=0.000).中剂量AUDA组显著性小于小剂量AUDA组(P=0.002),而大剂量AUDA也显著性小于小剂量AUDA组(P =0.000)和中剂量AUDA组(P=0.006).TUNEL染色法显示,假手术组仅可见少量凋亡细胞[(6.400±1.477)个/高倍视野].生理盐水对照组以及小剂量、中剂量和大剂量AUDA组凋亡细胞数量分别为(57.550±13.067)、(47.030±8.423)、(34.530±4.393)和(26.400±2.683)个/高倍视野,各剂量AUDA组显著性少于生理盐水对照组(P均＜0.01),中剂量和大剂量AUDA组显著性少于小剂量AUDA组(P均＜0.01),大剂量AUDA组也显著性少于中剂量AUDA组(P＜0.01).免疫组织化学显示,假手术组仅可见少量p-Akt阳性细胞[(3.325±1.438)个/高倍视野],生理盐水对照组以及小剂量、中剂量和大剂量AUDA组p-Akt阳性细胞数量分别为(9.450 ±2.531)、(16.400 ±3.865)、(22.875±7.974)和(29.300±3.203)个/高倍视野,各剂量AUDA组显著性多于生理盐水对照组(P均＜0.01),中剂量和大剂量AUDA组显著性多于小剂量AUDA组(P均＜0.01),大剂量AUDA组也显著性多于中剂量AUDA组(P＜0.01).结论 抑制sEH可能通过上调PI3K/Akt通路减少梗死周围区神经元凋亡和缩小梗死体积,对局灶性脑缺血再灌注大鼠具有神经保护作用.     

糖尿病通过抑制VEGF/VEGFR2通路加重大鼠缺血性脑损伤

目的 探讨缺血皮质血管内皮生长因子(vascular endothelial growth factor,VEGF)和VEGF受体2(VEGF receptor 2,VEGFR2)表达对糖尿病大鼠缺血性脑损伤的影响.方法 36只健康雄性Sprague-Dawley大鼠按随机数字表法分为假手术组、脑缺血组和糖尿病脑缺血组.腹腔注射链脲佐菌素制作糖尿病模型,然后再应用栓线法建立大鼠永久性局灶性脑缺血模型.在缺血后24 h进行神经功能缺损评分,氯化三苯基四氮唑染色测量梗死体积,TUNEL法检测凋亡细胞,实时荧光定量聚合酶链反应检测VEGF和VEGFR2 mRNA表达水平,蛋白质印迹法检测VEGF和VEGFR2蛋白表达水平.结果 假手术组无神经功能缺损,无梗死灶,仅有少量凋亡细胞以及少量VEGF和VEGFR2mRNA和蛋白表达.糖尿病脑缺血组神经功能评分[(4.25±0.54)分对(2.86±0.73)分;t=5.303,P ＜0.001]、梗死体积[(51.69 ±2.26)mm3对(30.15 ±2.08)mm3;=23.166,P＜0.001]和凋亡细胞数量[(24.22±1.34)个/HP对(13.28 ±0.37)个/HP;t =27.261,P＜0.001]均较脑缺血组显著增高和增加,而VEGF和VEGFR2 mRNA以及蛋白表达水平则较脑缺血组显著降低(VEGF mRNA:4.74±0.54对6.71 ±0.91,P＜0.001;VEGFR2 mRNA:4.06±0.60对6.16±0.96,P＜0.001;VEGF蛋白:0.99 ±0.13对1.55 ±0.23,P＜0.001;VEGFR2蛋白:4.12±0.74对6.23±0.76,P＜0.001).结论 VEGF/VEGFR2信号通路参与了糖尿病加重脑缺血损伤的过程,VEGF和VEGFR2表达下调可能是糖尿病加重脑缺血损伤的机制之一.     

汉黄芩素对慢性脑缺血大鼠空间记忆的影响及其可能机制

目的 探讨汉黄芩素对慢性脑缺血大鼠行为学的影响和可能机制.方法 大鼠随机分为假手术组、汉黄芩素干预组和磷酸盐缓冲液(phosphate buffered solution,PBS)对照组.采用二血管闭塞法制作慢性脑缺血大鼠模型.模型制作后6周,汉黄芩素干预组和PBS对照组分别给予汉黄芩素(50 μmol/L,10 ml/kg,1次/d)和等体积PBS灌胃,共14 d.采用Morris水迷宫实验评价空间学习和记忆功能,激光共聚焦三维血管成像检测缺血脑组织血管增殖,5-溴脱氧尿嘧啶核苷(5-bromo-2-deoxyuridine,BrdU)免疫组化染色检测脑缺血区细胞增殖情况,透射电镜检测缺血区神经细胞形态学变化.结果 Morris水迷宫实验(n=8)显示,汉黄芩素干预组训练第2至第5天的逃避潜伏期分别为(43.45 ±8.64)s、(37.12±1.31)s、(34.75±5.36)s和(24.36±5.43)s,显著性短于PBS对照组的(51.69±5.32)s、(43.65±9.21)s、(50.19±10.31)s和(53.65±7.15)s(P均＜0.05);汉黄芩素干预组第一象限游泳时间较PBS对照组显著延长[(26.16±3.29)s对(14.38±2.16)s;P＜0.01].激光共聚焦三维血管成像检测(n=4)显示,与PBS对照组比较,汉黄芩素干预组脑缺血区毛细血管内径显著缩小[(3.02±0.21)μm对(3.35±0.18)μm;P ＜0.05],血管密度显著增高[(205.80±12.70)/0.002mm3对(158.42±10.92)/0.002 mm3;P＜0.01],微血管总面积显著增加[(833 89±4 026)μm2/0.002 mm3对(73 349±3 986)μm2/0.002 mm3;P＜0.01].免疫组化染色(n=6)显示,汉黄芩素干预组缺血脑组织BrdU阳性细胞数量较PBS对照组显著增多[(24.62±3.25)个/高倍视野对(9.87±2.89)个/高倍视野;P＜0.01].透射电镜观察显示,汉黄芩素干预组细胞间隙炎性水肿较PBS对照组明显减轻.结论 汉黄芩素可显著改善慢性脑缺血大鼠空间学习和记忆能力,其可能的机制包括促进缺血区细胞增殖和血管发生,减轻炎症反应.     

脂氧素A4通过下调肿瘤坏死因子-α和核因子-κB保护脑缺血再灌注糖尿病大鼠

目的 探讨脂氧素A4对糖尿病大鼠脑缺血再灌注损伤的保护作用及其机制.方法 36只成年雄性Sprague-Daw ley大鼠随机分为假手术组、脑缺血再灌注组和脂氧素A4组,每组12只.应用小剂量链脲佐菌素多次腹腔注射诱发糖尿病,采用线栓法制作大脑中动脉闭塞再灌注模型.脂氧素A4组于脑缺血后5 min经侧脑室注射脂氧素A4 0.03 nmol/5μl,其余各组注射等容量生理盐水,缺血2h后拔出线栓实现再灌注.24 h时行神经功能缺损评分,然后断头取脑,2,3,5-氯化二苯四氮唑(2,3,5-triphenyl tetrazolium chloride,TTC)染色检测脑梗死面积,蛋白质印迹法检测缺血区皮质肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)和核因子-κB(nuclear factor-κB,NF-κB)表达.结果 神经功能缺损评分显示,假手术组未见神经功能缺损(评分为0分),脂氧素A4组神经功能缺损评分显著低于脑缺血再灌注组[(2.20±1.03)分对(3.20±1.03)分;P＜0.05].TTC染色显示,假手术组未见梗死灶,脂氧素A4组梗死面积较脑缺血再灌注组显著缩小[(27.52±5.71)％对(55.45±9.29)％;P＜0.05].蛋白质印迹显示,假手术组、脑缺血再灌注组和脂氧素A4组TNF-α表达水平分别为0.64±0.16、1.85±0.52和1.40±0.34,3组间存在显著性差异(F=18.868,P＜0.001),旨氧素A4组显著低于脑缺血再灌注组(P＜0.05);假手术组、脑缺血再灌注组和脂氧素A4组NF-κB表达水平分别为0.79±0.24、2.09±0.47和1.27±0.35,3组间亦存在显著性差异(F=16.736,P＜0.001),脂氧素A4组显著低于脑缺血再灌注组(P＜0.05).结论 脂氧素A4对糖尿病大鼠局灶性脑缺血再灌注损伤具有一定的保护作用,其机制可能与抑制TNF-α和NF-κB表达有关.     

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.     

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.     

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.     

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.