人肝癌SMMC-7721细胞受体介导内吞高密度脂蛋白-2的逆向胞饮作用

荧光素异硫氰酸酯标记高密度脂蛋白－２保持天然高密度脂蛋白－２的生物活性。人肝癌ＳＭＭＣ－７７２１细胞与荧光标记无载脂蛋白Ｅ－高密度脂蛋白－２在３７℃培养３ｈ左右，细胞结合与内吞的荧光强度分别为１３．５±０．８和９．２±０．５（±ｓ土）。细胞进一步在３７℃培养２ｈ细胞释放的三氯醋酸沉淀和三氯醋酸可溶性荧光强度分别为５．１±０．４和０．６７±０．１７．４℃培养２ｈ，细胞释放三氯醋酸沉淀荧光强度为０．４１±０．１６。结果提示：①细胞内吞高密度脂蛋白－２没有经过溶酶体分解途径；②细胞释放高密度脂蛋白－２载脂蛋白是一种取决于温度的逆向胞饮机制。     

激活巨噬细胞抑制载脂蛋白AI促细胞胆固醇流出能力

为探讨巨噬细胞活化对载脂蛋白ＡＩ促胆固醇外流能力的影响,用炎症诱发剂活化鼠腹腔巨噬细胞,３Ｈ标记乙酰低密度脂蛋白作泡沫细胞诱导物,巨噬细胞衍化的泡沫细胞与载脂蛋白ＡＩ孵育一段时间后,测定由细胞释放入培养基中的３Ｈ标记胆固醇量。结果发现,载脂蛋白ＡＩ浓度为２０ｍｇ／Ｌ时,从被活化的细胞释放至基质中的３Ｈ标记胆固醇量［（４．１５±０．４１）×１０－１ｄｐｍ／ｇ细胞蛋白］显著低于未被活化的细胞［（５．６９±０．１２）×１０－１ｄｐｍ／ｇ细胞蛋白］（Ｐ＜０．０１）,但高密度脂蛋白清除细胞胆固醇能力两组细胞无显著差异。提示巨噬细胞活化可显著抑制载脂蛋白ＡＩ促细胞胆固醇外流能力。     

人右心室心外膜下细胞瞬间外向钾电流的初步研究

两例终末期心脏来源于心脏移植的受体病人 ,用酶解分离法获得心外膜下 (Epi)细胞 ,在全细胞钳制条件下观察人右心室Epi细胞瞬间外向钾电流 (Ito1 )的电生理特性。结果发现 :①Epi细胞具有强大的Ito1 ,在 0 .2Hz、+70mV和 37℃条件下 ,Epi细胞的峰值Ito1 离子流强度和密度分别达 1 940± 440pA、1 2 .9± 2 .6pA/pF ;②温度对Ito1 强度的影响明显 ,在 +70mV、0 .2Hz、2 2℃和 37℃条件下 ,Epi细胞峰值Ito1 强度和密度分别为 1 1 90± 31 0pA和 7.7±1 .8pA/pF、1 960± 465pA和 1 3 .1± 2 .8pA/pF ,差异有显著性 (P均 <0 .0 1 ) ;③Epi细胞Ito1 离子流强度表现出明显的频率依赖性 ,在 37℃和 +70mV、刺激频率分别为 0 .2 ,0 .5 ,1和 2Hz时 ,Epi细胞Ito1 离子流强度分别为 1 91 0±42 0 ,1 660± 360 ,1 4 1 0± 2 50 ,830± 1 4 0pA ,差异均有显著性 (P均 <0 .0 1 )。结论 :人右心室Epi细胞存在强大的Ito1 ,此为人右心室Epi细胞复极 1期一个突出的电生理特点 ,可能是Brugada综合征等疾病所致恶性心律失常的重要离子基础之一。     

载脂蛋白C Ⅲ拮抗低密度脂蛋白对内皮细胞的损伤

为探讨高密度脂蛋白-载脂蛋白和载脂蛋白CⅢ在保护内发细胞免受低密度脂蛋白损伤方面所起的作用。将体外培养的人脐静脉内皮细胞分成对照组、高密度脂蛋白-载脂蛋白 低密度脂蛋自组、载脂蛋白CⅢ 低密度脂蛋白组和低密受脂蛋白组4组。通过观察细胞形态变化、测定乳酸脱氢酶释放率和前列环素合成，来观察低密度脂蛋白对内皮细胞形态和功能的影响、结果发现．低密度脂蛋白可引起内皮细胞收缩、细胞膜损伤、乳酸脱氢酶释放增加和前列环素合成减少。预加入高密度脂蛋白-载脂蛋白或载脂蛋白CⅢ（100mg／L）．内皮细胞再受到低密度脂蛋白（1.5g/L）的损伤时，细胞形态和功能不发生明显改变。提示高密度脂蛋白-载脂蛋白和载脂蛋白CⅢ均能部分拮抗低密度脂蛋白对内皮细胞的损伤。     

糖基化终产物促进U937巨噬细胞高密度脂蛋白受体的表达

目的　研究糖基化终产物对U937巨噬细胞高密度脂蛋白受体表达的影响。方法　将糖基化终产物与诱导分化4 8h后的U937细胞共同孵育,用免疫细胞化学法和半定量逆转录聚合酶链反应检测细胞清道夫受体BI蛋白及mRNA的表达。结果　免疫细胞化学法检测10 0、2 0 0和4 0 0mg/L糖基化终产物刺激后U937巨噬细胞清道夫受体BI蛋白表达的平均积分光密度值分别为18.94±3.5 6、2 7.86±4 .39及35 .0 8±2 .37,较牛血清白蛋白组明显升高(13.76±3.74 ,P <0 .0 5 ) ;4 0 0mg/L糖基化终产物作用6、12、2 4及4 8h后,细胞清道夫受体BI表达的平均积分光密度值分别为16 .87±5 .6 5、2 5 .6 8±6 .97、35 .0 8±8.37及39.6 8±9.37,较0h组明显升高(12 .0 2±3.4 7,P <0 .0 5 )。半定量逆转录聚合酶链反应结果显示,4 0 0mg/L牛血清白蛋白及10 0、2 0 0和4 0 0mg/L糖基化终产物刺激后细胞清道夫受体BImRNA相对表达量分别是0 .32±0 .0 3、0 .5 3±0 .0 5、0 .6 4±0 .0 4和0 .89±0 .0 5 ;4 0 0mg/L糖基化终产物作用0、6、12、2 4及4 8h后,U937巨噬细胞清道夫受体BImRNA相对表达量分别为0 .4 1±0 .0 1、0 .6 2±0 .0 5、0 .80±0 .0 8、0 .87±0 .0 5、1.2 4±0 .13。结论　糖基化终产物可增加U937巨噬细胞高密度脂蛋白受体蛋白     

霉酚酸对外周血T淋巴细胞活化抗原表达和增殖的影响

目的　探讨免疫抑制剂霉酚酸酯的活性代谢产物霉酚酸 (MPA)对外周血T淋巴细胞活化、增殖的影响。方法　分离外周血单个核细胞 ,以植物血凝素 (PHA)作为刺激剂 ,加或不加免疫抑制剂MPA和环孢素A(CSA) ,分组体外培养。以流式细胞仪检测 :T淋巴细胞表面标志CD3 ;T细胞活化抗原CD69/CD3 、CD2 5/CD3 、溴尿嘧啶脱氧核糖核苷 (BrdU)掺入率及细胞周期。结果　 (1)MPA、CSA均能显著抑制T淋巴细胞表面标志抗原CD3 的表达 ,96h时 ,MPA浓度 1组、CSA浓度 1组分别为(37 6 0± 7 89) %、(5 5 85± 13 6 4 ) % ,与对照组 (74 2 0± 7 5 1) %比较 ,差异有显著性 (P值分别为0 0 0 0、0 0 0 4 ) ;(2 )对预先活化 72h的T淋巴细胞 ,MPA能显著抑制CD3 的表达 ,继续培养 96h时 ,MPA组、CSA组分别为 (5 2 90± 7 35 ) %、(6 5 0 5± 10 82 ) % ,与对照组 (78 80± 5 0 9) %比较 ,差异有显著性(P值分别为 0 0 4 9、0 188) ;(3)MPA、CSA均不影响 2 4h时T淋巴细胞CD69的表达 ,MPA组、CSA组分别为 (5 5 0 3± 13 98) %、(38 30± 17 38) % ,与对照组 (5 0 11± 19 2 8) %比较 ,差异无显著性 (P >0 0 0 5 ) ;(4)MPA、CSA均能抑制T细胞表面CD2 5的表达 ,72h时 ,MPA浓度 1组、CSA浓度 1组分别为(37 15± 7 15 ) %、(6 2     

犬右心室心外膜下细胞瞬间外向钾电流特性的研究

目的　探讨犬右心室心外膜下 (Epi)细胞复极 1期瞬间外向钾电流 (Ito1)的电生理特性。方法　应用全细胞钳制技术 ,对右心室Epi细胞复极 1期Ito1的电流强度、动力学过程和动作电位切迹进行定量观察。结果　 (1)犬右心室Epi细胞具有强大的Ito1,其激活过程呈明显的电压依赖性 ,在37℃、0 2Hz和去极化试验电压为 +70mV时 ,Epi细胞的峰值Ito1强度和密度分别达 (4 15 0± 1780 )pA和 (31± 11 4)pA/pF ,其激活和失活动力学过程符合Boltzmann分布 ;(2 )犬右心室Epi细胞Ito1具有明显的频率依赖性 ,即在基础刺激周长增加时 ,Ito1明显增大 ,并和动作电位的“尖峰 穹隆”幅度的增加相对应 ;(3)温度对Ito1强度的影响明显 ,在去极化试验电压为 +70mV、0 2Hz和温度为 2 2℃、37℃条件下 ,右心室Epi细胞的Ito1强度和密度分别为 (2 380± 10 5 0 )pA与 (18± 7 6 )pA/pF、(4 15 0± 1780 )pA与 (31± 11 4)pA/pF ,差异明显。结论　犬右心室Epi细胞存在强大的Ito1,这种具有明显电压依赖性、频率依赖性和温度依赖性的Ito1及其参与介导的“尖峰 穹隆”状动作电位图形是右心室Epi细胞复极1期一个突出的电生理特点。     

羟基磷灰石纳米粒子对人肝癌BEL-7402细胞毒性的评价

目的　从抑制细胞生长增殖和诱导细胞凋亡角度评价羟基磷灰石纳米粒子对人肝癌BEL 740 2细胞的细胞毒性。方法　将羟基磷灰石纳米粒子以不同终浓度、不同时间作用于人肝癌BEL 740 2细胞 ,用MTT比色法观察其细胞毒性 ,荧光显微镜、透射电镜检测细胞凋亡形态改变 ,前者同时记数凋亡指数 ,流式细胞仪定量分析细胞凋亡率。结果　羟基磷灰石纳米粒子以剂量依赖和时间依赖的方式抑制BEL 740 2细胞的生长 ,作用 48h后的半数有效抑制浓度IC50 值为 2 9.3 0 μg/ml。荧光显微镜和透射电镜观察到细胞皱缩、核质浓缩、核碎裂、细胞起泡以及凋亡小体形成等凋亡特性的形态学改变。流式细胞仪直方图上可见亚二倍体峰。浓度为 5 0 μg/ml、75 μg/ml、10 0 μg/ml、15 0 μg/ml、2 0 0 μg/ml的纳米粒子处理 48h后 ,细胞凋亡率分别为 ( 2 0 .3 5± 2 .2 3 ) %、( 2 5 .3 5± 1.92 ) %、( 2 9.3 4± 4.61) % ,( 4 4.92± 3 .78) %和( 5 3 .64± 3 .49) % ,与对照组 ( 2 .2 3± 0 .14 ) %比较均有显著性差异。 5 0 μg/ml浓度作用 12h、2 4h、3 6h和 48h后的细胞凋亡率分别为 ( 2 .73± 0 .17) %、( 3 .5 2± 0 .3 5 ) %、( 6.3 7± 0 .3 4) %和 ( 2 1.64± 2 .46) % ,与对照组 ( 2 .2 3± 0 .14 ) %比较亦均有显著性差异     

过氧化体增殖物激活型受体γ和δ在高密度脂蛋白介导细胞胆固醇流出中的作用

为探讨过氧化体增殖物激活型受体γ和δ在高密度脂蛋白介导的细胞胆固醇流出中的作用。取新鲜抗凝血浆 ,用超速离心机进行密度梯度离心 ,收集密度为 1 .0 6 3～ 1 .2 1 0组分。U937细胞用 5 0～ 4 0 0nmol L反义过氧化体增殖物激活型受体γ和δ预处理细胞 1 2h。培养U937细胞与 0 .2 8mCi L [3H] 胆固醇乙醇液共孵育 2 4h ,15 0 0r min离心 1 0min ,收集细胞 ,PBS漂洗 2次 ,RPMI 1 6 4 0重悬细胞 ,加HDL继续培养 0～ 4 8h。液体闪烁计数仪测细胞相对放射活性。Westernblot检测过氧化体增殖物激活型受体γ和δ蛋白表达水平。不同浓度HDL处理后细胞胆固醇流出具有明显差异 ,呈剂量 -效应关系。用 1 0 0nmol L反义过氧化体增殖物激活型受体γ处理 2 4h后 ,HDL介导的细胞胆固醇流出减少 (4 5 78± 2 0 6 ) ,与对照组 (4 0 2 4± 385 )比较差别有显著性。过氧化体增殖物激活型受体γ激动剂ciglitizone预处理后 ,HDL介导的细胞胆固醇流出增加 ,用 0、2 5、5 0、1 0 0、2 0 0 μmol Lciglitizone处理的放射活性分别为 4 371± 2 4 3、386 9± 2 1 2、346 9± 2 0 9、31 5 6± 31 5和 30 2 0± 2 96。反义过氧化体增殖物激活型受体δ处理后 ,HDL介导的细胞胆固醇流出略有增加 ,处理浓度达 4 0 0nmol L时的放射活     

正常人餐后甘油三酯动态代谢对血清一氧化氮和血浆内皮素1的影响

为探讨正常人脂肪负荷后甘油三酯动态代谢对血清一氧化氮和血浆内皮素 1浓度的影响 ,取 2 0例正常人标准脂肪餐前 (0h)、餐后 2、4、6和 8h外周静脉血 ,分离血清 ,测定甘油三酯、总胆固醇、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇、载脂蛋白AⅠ和载脂蛋白B水平 ,放射免疫法测定血浆内皮素 1浓度 ,比色法测定血清一氧化氮相对浓度 ,计算一氧化氮 /内皮素 1比值。结果发现 ,餐后 2h血清甘油三酯浓度显著高于餐前 (2 .19± 0 .16比 1.161.16± 0 .11mmol/L ,P <0 .0 5 ) ,4h达到高峰 (3.34± 0 .37mmol/L) ,8h恢复至餐前水平。餐后 2h血浆一氧化氮浓度存在一过性升高 (61.5 8± 5 .97比 42 .5 0± 7.42ng/L ,P <0 .0 5 ) ,6、8h又显著降低 (37.60± 5 .71比 61.5 8± 5 .97ng/L ;30 .76± 5 .0 1比 61.5 8± 5 .97ng/L ,P <0 .0 5 )。餐后 2h内皮素 1浓度较餐前显著降低(99.0 8± 16.5 5比 114.2 2± 16 .45ng/L ,P <0 .0 5 ) ,餐后 6、8h较 2h显著升高 (113.82± 19.80比 99.0 8± 16 .5 5ng/L ,12 1.0 2± 19.5 5比 99.0 8± 16.5 5ng/L ,P <0 .0 5 ) ,餐后 8h较 4h高 (12 1.0 2± 19.5 5比 10 3.45± 19.87ng/L ,P <0 .0 5 )。同样 ,一氧化氮 /内皮素 1比值在餐后 2h存在高峰 (0 .78± 0 .13比 0 .46±     

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.     

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.     

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.     

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.