N-乙酰半胱氨酸对非酒精性脂肪性肝炎模型小鼠肝细胞线粒体自噬的影响

目的在非酒精性脂肪性肝炎模型小鼠中探索N-乙酰半胱氨酸(NAC)对肝细胞线粒体自噬的影响。方法C57BL/J6小鼠分别给予16周的正常饮食、高脂高糖(HFCD)饮食和HFCD+NAC饮食。比较HE和Masson染色、ALT、AST、IL-1β、肝组织甘油三酯水平评价小鼠肝损伤。通过免疫荧光染色观察线粒体自噬。比较3组小鼠肝组织内线粒体自噬标志物在mRNA和蛋白水平的变化。结果HFCD组小鼠较对照组ALT[(24.9±2.12)比(176.7±44.32)U/L,P<0.05]、AST[(76.7±9.06)比(291.3±39.66)U/L,P<0.05]、IL-1β[(2.94±0.08)比(9.12±1.21),P<0.05]显著升高,HFCD+NAC组较HFCD组肝功能好转,IL-1β降低[(9.12±1.21)比(6.77±0.58)ng/L,P<0.05]。HFCD组小鼠肝组织内Parkin、PINK1表达降低,同时LC3B II/I比值降低,P62表达量增高。提示HFCD组小鼠肝细胞线粒体自噬水平降低。HFCD+NAC组较HFCD组线粒体自噬水平升高,差异有统计学意义(P<0.05)。结论NAC可能通过改善肝细胞线粒体自噬,进而减轻肝细胞炎症进展。     

NOD2通过调控细胞外基质活性及炎性因子水平介导心肌梗死后心室重构

目的探讨细胞内模式识别受体——核苷酸结合寡聚化结构域(NOD)蛋白家族中NOD2蛋白是否参与心肌梗死(MI)后心室重构及相关机制。方法结扎小鼠冠状动脉左前降支建立MI模型。实时荧光定量PCR检测不同梗死时间假手术组、手术组梗死区、手术组非梗死区NOD2的m RNA表达水平,免疫组化染色和Western blot测定梗死28 d心肌组织NOD2的蛋白表达。采用NOD2-/-基因敲除小鼠建立MI模型,实验分为4组:野生/假手术组(WT/Sham组)、NOD2基因敲除/假手术组(NOD2-/-/Sham组)、野生/MI组(WT/MI组)和NOD2基因敲除/MI(NOD2-/-/MI组)。小动物超声心动图测定心室重构指数并判断心功能,Masson和Tunel染色观察小鼠心梗后心肌纤维化程度及细胞凋亡情况,酶联免疫吸附法(ELISA)测定梗死心肌组织的促炎细胞因子水平,Western blot和明胶酶谱法检测心肌组织裂解液基质金属蛋白酶9(MMP-9)蛋白及活性变化,并用免疫组化染色观察MI后炎性细胞浸润和心脏成纤维细胞转分化成心肌成纤维细胞情况。结果与WT/Sham组相比,WT/MI组非梗死区和梗死区NOD2 m RNA表达水平均升高(均为P 0. 05),其中梗死区NOD2的m RNA表达及蛋白表达最高。超声心动图提示,NOD2缺失能减轻MI后心功能障碍和心室重构的程度; Tunel和Masson染色显示,NOD2-/-/MI组的细胞凋亡和心肌纤维化程度均明显降低(均为P 0. 05)。NOD2缺失还能降低MI区炎性因子水平、炎性细胞的浸润及MMP-9的活性(均为P 0. 05)。结论 NOD2通过调控MMP-9蛋白及活性、炎性介质水平和炎性细胞浸润来介导MI后心室重构过程。     

姜黄素激活自噬对抗ANGII诱导的心肌纤维化发生*

目的 姜黄素(Curcumin,CMN)是从姜黄属根茎中提取的一种多酚化合物。已有研究提示,其具有抗细胞氧化、降脂、减轻炎症反应、抗肿瘤等作用,干预多种炎性疾病的发生。本研究尝试进一步阐明其在病理性心肌纤维化炎症中的作用及机制。方法 以血管紧张素II(Angiotension II, ANGII)作为刺激因子制备小鼠心肌纤维化疾病模型,以不同浓度的CMN(50,100ng/mL)作为干预浓度进行治疗研究。应用小动物超声检测干预28d后各组小鼠心功能指标。应用HE和Masson染色方法观察干预28d后小鼠心肌病理损伤及纤维化情况。应用Western blot方法检测Ⅲ型胶原和自噬相关蛋白(LC3和P62)表达。结果 心功能检测发现,CMN治疗后,可呈剂量依赖性对抗ANGII诱导的小鼠心肌损伤。HE和Masson染色进一步证实,CMN高浓度治疗组小鼠心肌损伤受到抑制,心肌纤维化程度显著减轻,心肌组织Ⅲ型胶原表达显著减少。应用Western blotting证实,CMN干预后,可明显激活小鼠心肌的自噬水平,促进自噬发生。进一步应用自噬抑制剂氯喹干预治疗后,Masson染色提示,CMN对抗ANGII诱导的小鼠心肌纤维化作用受到明显抑制,同时,小鼠心肌自噬激活也明显受到抑制。结论 CMN通过激活心肌组织自噬活化对抗ANGII诱导的小鼠心肌纤维化发生。     

高表达microRNA-22改善小鼠心肌梗死后心功能

目的观察高表达microRNA-22对小鼠心肌梗死后心功能的保护作用及机制。方法构建小鼠心肌梗死模型,用携带microRNA-22的腺病毒载体转染至心肌梗死周围区域,观察高表达microRNA-22对小鼠心肌梗死后心功能的保护作用。采用超声心动图检测心功能,力竭游泳检测运动能力,HE及Masson染色检测心肌微结构及纤维化,Western blot检测PTEN蛋白表达情况。结果高表达microRNA-22组小鼠左心室射血分数(LVEF)(49.38%±2.51%比42.29%±2.74%,P0.05)及短轴缩短率(FS)(24.24%±0.64%比22.59%±0.73%,P0.05)较空载腺病毒组升高,心脏收缩功能维持较好;高表达microRNA-22组力竭运动时间较空载腺病毒组延长(8.13±1.01min比7.02±1.32 min,P0.05),小鼠整体运动能力改善;高表达microRNA-22组小鼠HE染色示心肌结构维持较好,Masson染色示心肌纤维化程度较轻;高表达microRNA-22组心肌梗死周围区域内microRNA-22表达增加(6.66±2.01比1.22±0.07,P0.05),PTEN蛋白表达下降(0.63±0.19比2.23±0.44,P0.05)。结论小鼠心肌梗死后在体高表达microRNA-22改善心脏收缩功能及运动能力,改善心肌微结构,减轻心肌纤维化。     

Toll样受体2与异丙肾上腺素诱导的心肌纤维化的相关性研究

目的 探讨Toll样受体2(TLR2)对异丙肾上腺素(ISO)诱导的心功能不全和心肌纤维化的影响,探讨TLR2对ISO诱导的心脏成纤维细胞中自噬的影响及TLR2介导的高迁移率族蛋白1(HMGB1)导致心脏成纤维细胞中的自噬抑制进而导致心肌纤维化的机制。方法 使用雄性C57BL/6及TLR基因敲除小鼠各16只,分成4组,每组各8只,分别为:野生型对照组[WT(Vehicle)]、基因敲除对照组[TLR2-/-(Vehicle)]、野生型给药组(WT+ISO)、基因敲除给药组(TLR2-/-+ISO)。WT+ISO组、TLR2-/-+ISO组均通过肩胛皮下注射ISO制备了小鼠的心肌纤维化模型,WT(Vehicle)、TLR2-/-(Vehicle)组相应部位注射生理盐水。查超声心动图了解小鼠心脏功能,HE染色及天狼猩红染色评估心肌细胞损伤心肌纤维化程度,通过免疫印迹实验来检测心肌自噬相关蛋白哺乳动物雷帕霉素结合位点(mTOR)、p-mTOR、轻链3(LC3)、可溶性及不可溶性p62在成纤维细胞中的表达。通过电镜来观察心脏的超微结果和自噬小体。分离小鼠的心脏成纤维细胞,并用不同浓度的HMGB1刺激心脏成纤维细胞,同时免疫印迹实验来检测α平滑肌肌动蛋白(α-SMA)、I型胶原和自噬标志性蛋白p-mTOR、mTOR、LC3、可溶性及不可溶性p62的表达。HMGB1与TLR2,α-SMA与p62之间的互相作用通过免疫共沉淀和免疫荧光共定位来检测。结果 HE病理结果和电镜结果可见WT+ISO组心肌损伤最重,TLR2-/-+ISO组心肌损伤最轻。天狼星染色可见,WT+ISO组心肌疤痕区胶原积聚较多,TLR2-/-(Vehicle)组则分泌减少,两者比相存在差异(P0.01)。免疫印迹实验证实,WT+ISO组心肌组织中collagen I(I型胶原)的表达与TLR2-/-+ISO组比较明显增加(P0.05)。免疫荧光共定位实验证实,WT+ISO组HMGB1含量增加最明显(P0.01)。免疫印迹检测自噬标志性蛋白的表达:与WT+ISO组可溶性P62增加最显著(P0.01),P-mTOR和mTOR的比值在WT+ISO组增加最明显(P0.01),WT+ISO组LC3II/I的比值的减小最明显(P0.01),此外,与其他组相比,WT+ISO组不可溶性P62堆积最明显,TLR2-/-组较少,存在显著性差异(P0.01)。在电镜下观察心肌细胞中的自噬小体,发现WT+ISO组自噬小体数量明显少于其他组,而TLR2-/-+ISO组自噬小体较野生组显著增加,且差异有统计学意义(P0.01,P0.05)。结论 TLR2介导细胞外的HMGB1使成纤维细胞内自噬流发生阻塞,使选择性自噬接头蛋白p62堆积,进而使α-SMA的转运及降解受阻,从而导致心肌纤维化。因此,可以将HMGB1作为治疗的靶点。     

补体5a受体在阿霉素致急性心力衰竭心肌损伤的早期研究

目的:探讨补体系统补体5a受体(complement 5a receptor,C5aR)在急性心力衰竭(心衰)早期,对心脏功能影响以及对心肌损伤的作用。方法:选择12 w龄C57BL/6J野生型及C5aR敲除小鼠各12只,分别随机分为野生小鼠对照组、野生小鼠心衰组、C5aR敲除小鼠对照组和C5aR敲除小鼠心衰组等共4组,每组6只。采用单次腹腔注射阿霉素20 mg/kg建立小鼠急性心衰模型,对照组采用同计量0.9%氯化钠液注射;阿霉素注射3d后显微超声检测小鼠心室射血分数和短轴缩短率,处死后测量体质量以及心脏质量;运用半定量PCR、蛋白印迹技术Western Blotting、免疫荧光等实验方法观察C5aR在野生小鼠心脏中的表达。C5aR敲除小鼠心脏组织采用HE染色观察心肌形态、Masson染色观察心肌纤维化程度,WGA染色观察心肌横截面大小,免疫组化染色观察转化生长因子-β(TGF-β)及α-平滑肌肌动蛋白(α-SMA)在心脏中表达。结果:与野生小鼠对照组相比,野生小鼠心衰组中C5aR的mRNA及蛋白表达均显著上调(P<0.05);与野生小鼠心衰组相比,C5aR敲除小鼠心衰组体质量及血压均显著升高(均为P<0.05),心室射血分数和短轴缩短率均显著升高(均为P<0.05),C5aR敲除小鼠心衰组胶原沉积及α-SMA表达均显著降低(均为P<0.05),TGF-β表达显著降低(P<0.01)。结论:C5aR在阿霉素诱导心衰模型中表达上调、加重了心肌损伤且促进了心脏纤维化,而C5aR敲除保护小鼠心功能并抑制纤维化,提示C5aR在小鼠急性心衰早期具有促进心脏纤维化作用。     

Toll样受体4在血管紧张素Ⅱ致高血压小鼠心脏纤维化中的作用

目的探讨Toll样受体4(TLR4)在血管紧张素Ⅱ(AngⅡ)所致高血压小鼠心脏纤维化过程中的作用。方法野生型C57小鼠18只分为3组:空白对照组、AngⅡ组和TLR4阻断组,每组6只。AngⅡ组和TLR4阻断组AngⅡ微量泵灌注建立高血压模型,TLR4阻断组尾静脉注射TLR4中和抗体后,小鼠尾动脉套法测血压,心动超声图观察小鼠的心脏功能变化。免疫组织化学、Masson染色观察心脏纤维化。RT-PCR检测心肌白细胞介素1β和单核细胞趋化蛋白1 mRNA表达。结果与AngⅡ组比较,TLR4阻断组小鼠血压降低,左心室舒张末期壁厚度减少,舒缩未期左心室内径增加(P<0.05)。心肌组织半乳糖凝集素2阳性巨噬细胞浸润减少,白细胞介素1β和单核细胞趋化蛋白1 mRNA表达水平降低(P<0.05)。小鼠心肌间质和血管周围纤维化减轻(P<0.05)。结论 TLR4通过介导炎性反应参与AngⅡ所致高血压小鼠心脏纤维化过程。     

阿托伐他汀对大鼠心肌梗死后心肌纤维化的干预作用

目的通过研究阿托伐他汀对大鼠急性心肌梗死(AMI)后periostin蛋白及转化生长因子β1(TGF-β1)mRNA的表达水平的影响,探讨阿托伐他汀对于AMI后心肌纤维化的干预作用机制。方法将60只SD雄性大鼠随机分为正常组(Sham)、单纯心肌梗死组(MI)和心肌梗死联合阿托伐他汀组(Ato);注射异丙肾上腺素造心肌梗死模型,Ato组于心肌梗死造模成功后给予阿托伐他汀5 mg/(kg·d)灌胃,MI组及Sham组以同等剂量生理盐水灌胃;各组分别于术后8周取材,病理技术:Masson染色观察并计算心肌纤维化中胶原纤维的容积分数(CVF);利用RT-PCR技术检测心肌periostin蛋白及TGF-β1 mRNA的表达水平。结果 Masson染色提示MI组及Ato组CVF均显著高于Sham组(P0.01);而Ato组CVF明显低于MI组(P0.05);RT-PCR结果MI组和Ato组较Sham组的TGF-β1 mRNA及periostin蛋白表达量均显著增加(P0.01);Ato组比MI组TGF-β1 mRNA及periostin蛋白的表达量显著下降(P0.05)。结论阿托伐他汀能够抑制periostin蛋白和TGF-β1 mRNA的表达,其机制可能为抑制TGF-β1/periostin信号传导通路,进而抑制心肌纤维化,并保护心脏功能。     

小鼠心肌梗死后补体系统激活与炎症反应的相关性研究

目的:探讨心肌梗死后补体系统激活的作用。方法:采用结扎冠状动脉左前降支的方法,复制心肌梗死小鼠模型,分为心肌梗死组(MI,n=25)与假手术组(Sham,n=12),术后7d超声心动图检测心功能;心肌组织HE染色观察炎症细胞浸润、Masson染色和天狼猩红染色观察胶原沉积与纤维化程度;Real-time PCR定量检测心肌组织中C3a与C5a的mRNA表达水平,并对C3a、C5a mRNA表达量与射血分数(EF)之间作相关性分析。结果:术后7d,MI组小鼠的生存率为68.0%,明显低于Sham组(P0.05);MI组的LVAWs、EF、FS均明显降低(P0.05);HE染色可见MI组有大量炎性细胞浸润,Masson染色与天狼猩红染色发现胶原纤维沉积、纤维化面积增加(P0.01);C3a与C5a的mRNA表达量增加,且这两项指标均与EF之间呈负相关。结论:心肌梗死后补体系统被激活,补体系统的活化程度与射血分数的降低有关,提示补体系统可能通过调控心肌组织的炎症反应和纤维化过程,成为加重心脏病理损伤的重要因素。     

心肌缺血/再灌损伤时TXNIP表达水平升高并增加心肌自噬

目的 探讨心肌缺血/再灌注（MI/R）时硫氧还蛋白相互结合蛋白（TXNIP）表达及对心肌细胞自噬水平的影响。 方法 构建TXNIP敲除鼠及TXNIP过表达小鼠,制作上述小鼠MI/R模型,观察MI/R后心肌TXNIP表达水平是否与心肌损伤及自噬有关。 结果 与假手术组（Sham）小鼠相比,小鼠心肌TXNIP表达水平在缺血及再灌注损伤过程中持续升高（P<0.01）。在小鼠MI/R后,心脏超声证实与野生型（WT）小鼠相比,TXNIP过表达小鼠LVEF（%）值更低（P<0.05）;伊文氏蓝/TTC染色同样证实TXNIP过表达小鼠心肌梗死面积更大（P<0.05）。而TXNIP敲除鼠MI/R后心脏LVEF（%）值（P<0.05）及心肌梗死面积（P<0.05）均较WT小鼠显著减轻。通过免疫印迹（LC3Ⅱ/LC3I及P62表达）及电子显微镜观察自噬小体检测发现,相比WT小鼠,TXNIP敲除小鼠心肌自噬程度更轻（P<0.05）,TXNIP过表达小鼠则心肌自噬程度更重（P<0.05）。 结论 上述结果证实了在MI/R后TXNIP升高导致心脏功能的降低,心肌梗死面积的增加及心肌细胞自噬的增多。     

Three layer functional model and energy exchange concept of aging process

Relying on a certain degree of abstraction, we can propose that no particular distinction exists between animate or living matter and inanimate matter. While focusing attention on some specifics, the dividing line between the two can be drawn. The most apparent distinction is in the level of structural and functional organization with the dissimilar streams of ‘energy flow’ between the observed entity and the surrounding environment. In essence, living matter is created from inanimate matter which is organized to contain internal intense energy processes and maintain lower intensity energy exchange processes with the environment. Taking internal and external energy processes into account, we contend in this paper that living matter can be referred to as matter of dissipative structure, with this structure assumed to be a common quality of all living creatures and living matter in general. Interruption of internal energy conversion processes and terminating the controlled energy exchange with the environment leads to degeneration of dissipative structure and reduction of the same to inanimate matter, (gas, liquid and/or solid inanimate substances), and ultimately what can be called ‘death.’ This concept of what we call dissipative nature can be extended from living organisms to social groups of animals, to mankind. An analogy based on the organization of matter provides a basis for a functional model of living entities. The models relies on the parallels among the three central structures of any cell (nucleus, cytoplasm and outer membrane) and the human body (central organs, body fluids along with the connective tissues, and external skin integument). This three-part structural organization may be observed almost universally in nature. It can be observed from the atomic structure to the planetary and intergalactic organizations. This similarity is corroborated by the membrane theory applied to living organisms. According to the energy nature of living matter and the proposed functional model, the decreased integrity of a human body's external envelope membrane is a first cause of the structural degradation and aging of the entire organism. The aging process than progresses externally to internally, as in single cell organisms, suggesting that much of the efforts towards the restoration and maintenance of the mechanisms responsible for structural development should be focused accordingly, on the membrane, i.e., the skin. Numerous reports indicate that all parts of the human body, like: bones, blood with blood vessels, muscles, skin, and so on, have some ability for restoration. Therefore, actual revival of not only aging tissue of the human body's membrane, but the entire human body enclosed within, with all internal organs, might be expected. We assess several aging theories within the context of our model and provide suggestions on how to activate the body's own anti-aging mechanisms and increase longevity. This paper presents some analogies and some distinctions that exist between the living dissipative structure matter and inanimate matter, discusses the aging process and proposes certain aging reversal solutions.     

Unusual responses of nocturnal pineal melatonin synthesis and secretion to swimming: Attempts to define mechanisms

Abstract: The effect of swimming at night on rat pineal melatonin synthesis was compared with that of light exposure at night. Rats were forced to swim at 0030 hr (lights out at 2000 hr) and sacrificed by decapitation 15 and 30 min later, immediately after swimming. Other groups of animals were exposed to white light (650μW/cm²) for 15 and 30 min at same time. Swimming caused a rapid and highly significant drop in the melatonin content in the pineal gland; however, the activity of N-acetyltransferase (NAT), the supposed rate limiting enzyme in the melatonin production, was not changed. Despite the drop in pineal melatonin levels, serum concentrations of the indole remained elevated in the rats that swam. In contrast, melatonin levels in the pineal and serum of light exposed rats fell precipitously, accompanied by a significant suppression of NAT activity. Since we anticipated that the strenuous exercise associated with swimming may induce release of artrial natriuretic peptide (ANP) from the heart, which in turn could cause the release of pineal melatonin, in a second study we injected physiological saline intravenously to stretch the cardiac muscle and release ANP. Three milliliters of normal saline was injected during the day into the jugular vein of anesthetized rats that were pretreated with isoproterenol to stimulate pineal melatonin production. Animals were killed 15 min after the saline injection, and pineal NAT activity and pineal melatonin levels were measured. The saline injections caused no alteration in the elevated levels of either NAT or melatonin. These data suggest that the disparity in pineal NAT activity (which was high) and pineal melatonin (which was low), in animals swum at night, may not be caused by ANP which is released during strenuous exercise such as swimming.     

Melatonin and photoperiodic time measurement: Seasonal breeding in the sheep

Abstract: Well-established circadian physiology supports the view that photoperiodic time measurement utilizes the coincidence between the presence of light and a photosensitive phase of a 'biological clock' to alter reproductive status—the so-called external coincidence model of seasonal breeding. In this review, we examine the mechanism whereby photoperiod interacts with presumed suprachiasmatic nuclei activity to allow endogenous melatonin to normally synchronize reproductive activity to the optimal time of year. The Romney Marsh sheep is particularly explored as an experimental model. It is suggested that the on/off activity of seasonal reproduction may be a robust mechanism able to be predictably manipulated by the judicious use of the light/dark cycle and exogenous melatonin, but firmly based on circadian principles.     

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.     

Serological survey of HIV and syphilis in pregnant women in Madagascar

Objectives Peripartal transmission of human immunodeficiency virus (HIV) and Treponema pallidum, the causative agent of syphilis, leads to severe consequences for newborns. Preventive measures require awareness of the maternal infection. Although HIV and syphilis testing in Madagascar could be theoretically carried out within the framework of the national pregnancy follow‐up scheme, the required test kits are rarely available at peripheral health centres. In this study, we screened blood samples of pregnant Madagascan women for HIV and syphilis seroprevalence to estimate the demand for systemic screening in pregnancy. Methods Retrospective anonymous serological analysis for HIV and syphilis was performed in plasma samples from 1232 pregnant women that were taken between May and July 2010 in Ambositra, Ifanadiana, Manakara, Mananjary, Moramanga and Tsiroanomandidy (Madagascar) during pregnancy follow‐up. Screening was based on Treponema pallidum haemagglutination tests for syphilis and rapid tests for HIV, with confirmation of positive screening results on line assays. Results Out of 1232 pregnant women, none were seropositive for HIV and 37 (3%) were seropositive for Treponema pallidum. Conclusions Our findings are in line with previous studies that describe considerable syphilis prevalence in the rural Madagascan population. The results suggest a need for screening to prevent peripartal Treponema pallidum transmission, while HIV is still rare. If they are known, Treponema pallidum infections can be easily, safely and inexpensively treated even in pregnancy to reduce the risk of transmission.     

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.     

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.