低密度脂蛋白免疫复合物对单核细胞源性巨噬细胞胆固醇代谢及低密度脂蛋白受体表达的影响

目的 研究动脉粥样硬化过程中低密度脂蛋白免疫复合物对单核细胞源性巨噬细胞胆固醇代谢和低密度脂蛋白受体表达的影响。方法 以佛波酯刺激分化的THP-1细胞作为单核细胞源性巨噬细胞模型。通过胆固醇酶联法测定细胞内胆圊醇含量，逆转录-聚合酶链反应检测细胞低密度脂蛋白受体mRNA的表达，Western blot检测细胞低密度脂蛋白受体蛋白的表达。结果 与低密度脂蛋白组、阴性组及IgG免疫复合物组比较，低密度脂蛋白免疫复合物组细胞内胆固醇水平明显增高，并且低密度脂蛋白受体mRNA及蛋白的表达增加。结论 低密度脂蛋白免疫复合物能显著增加巨噬细胞内胆固醇含量，亦能够促进低密度脂蛋白受体mRNA与蛋白的表达，提示低密度脂蛋白免疫复合物在动脉粥样硬化进展过程中起重要的作用。     

低密度脂蛋白免疫复合物对巨噬细胞细胞因子分泌的影响

目的探讨低密度脂蛋白免疫复合物(LDL-IC)对巨噬细胞细胞因子分泌的影响.方法设立终浓度均为150 μg/ml的LDL组、LDL-IC组、Igg-IC组及阴性对照组与细胞孵育相同时间,以ELISA法检测比较培养上清TNF-α和IL-1β水平.并观察不同LDL-IC浓度(0,50,100,150,200,250μg/ml)作用相同时间以及终浓度为150μg/ml的LDL-IC与细胞作用不同的时间(0,3,6,12,24,36 h),培养上清TNF-α和IL-1β水平.结果LDL-IC组培养上清TNF-α、IL-1β水平均明显高于LDL、IgG-IC及阴性对照组.TNF-α、IL-1β水平随着LDL-IC作用浓度的增加和作用时间的延长而增高.结论LDL-IC可以显著增加细胞TNF-α和IL-1β的分泌,具有剂量和时间依赖效应.提示LDL-IC能通过增加细胞因子分泌而在动脉粥样硬化中起重要作用.     

黄芪多糖在动脉粥样硬化发展过程中保护性作用的研究

目的:通过研究黄芪多糖(APS)对肿瘤坏死因子α(TNF-α)诱导的人急性单核白血病细胞(THP-1)源性泡沫细胞胆固醇流出率、细胞内总胆固醇含量以及细胞膜上脂质流出通道ATP-结合盒转运子A1(ABCA1)表达水平的影响,探讨APS在动脉粥样硬化发展过程中的保护作用。方法:将培养的THP-1源性巨噬细胞分为4组:对照组、单纯TNF-α组、TNF-α+APS组和单纯APS组。分别用RT-PCR法、Western blotting法检测ABCA1的mRNA及蛋白表达水平,闪烁计数法计算胆固醇流出率,酶化学法检测细胞内脂质含量,酶联免疫吸附法(ELISA法)测核因子-κB(NF-κB)的水平。结果:单纯TNF-α组ABCA1的mRNA和蛋白表达量、胆固醇流出率显著低于对照组(P<0.01),细胞内总胆固醇含量、NF-κB的水平显著高于对照组(P<0.05),而单纯APS组与对照组在上述指标上差异无统计学意义(P>0.05);与单纯TNF-α组比较,TNF-α+APS组ABCA1的mRNA和蛋白表达量、胆固醇流出率显著升高(P<0.01),细胞内总胆固醇含量、NF-κB的水平显著降低(P<0.01)。结论:APS能够使泡沫细胞ABCA1的表达及胆固醇流出率上升,而细胞内总胆固醇含量显著下降,并能够减弱泡沫细胞中NF-κB的活化水平。这些发现提示APS能够拮抗TNF-α对于ABCA1的下调作用,从而发挥抗动脉粥样硬化作用。     

冠心病患者巨噬细胞胆固醇流出的变化

目的研究冠心病患者血液中单核细胞分化为巨噬细胞并荷脂后胆固醇流出的影响机制。方法分离冠心病患者(试验组)和正常人群(对照组)外周静脉血中单核细胞,并用佛波酯诱导为巨噬细胞,收集分离血清,检测各项血脂指标并备用。细胞用[3H]胆固醇处理24 h使其荷脂,然后分为四组:对照组+正常血清、对照组+高脂血清、试验组+正常血清及试验组+高脂血清。分别检测ABCA1、ABCG1表达及胆固醇流出率。结果与对照组比较,试验组单核/巨噬细胞胆固醇流出能力受损,油红O染色显示细胞内脂质蓄积增加,细胞内胆固醇流出减少,但ABCA1和ABCG1的表达改变不明显。与正常血清比较,试验组及对照组中高脂血清明显影响胆固醇流出能力,细胞内脂质蓄积增加,细胞内胆固醇流出减少,但不影响ABCA1和ABCG1的表达。结论冠心病患者巨噬细胞胆固醇流出能力受损,可能与动脉粥样硬化性血管疾病的发生相关。     

黄芪注射液对人单核细胞源性泡沫细胞内胆固醇外流的影响

目的 观察黄芪注射液是否对人外周血单核细胞源性泡沫细胞内胆固醇外流产生作用和影响,从机体胆固醇逆转运(RCT)的角度探讨黄芪的调脂机制和抗动脉粥样硬化的作用.方法 采用密度梯度离心法和塑料吸附法从人外周血中分离出单核细胞,以50 nmol/L佛渡酯(PMA)刺激48 h使之转化为巨噬细胞.细胞分为对照组与实验组,以黄芪注射液干预后分别测定细胞内总胆固醇(TC)、游离胆固醇(FC)与蛋白(Pro)含量的变化,观察黄芪注射液对细胞内TC/Pro比影响的量效关系和时效关系.结果 成功建立人单核细胞源性泡沫细胞模型.经不同浓度黄芪注射液作用后,细胞中TC/Pro随黄芪注射液浓度的增加而呈剂量依赖性降低,细胞泡沫化程度也随着药物浓度的升高而降低(P<0.01),且在药物浓度一定的情况下,细胞中TC/Pro随黄芪注射液处理时间的延长而呈时间依赖性降低(P<0.01).结论 黄芪注射液通过降低细胞内TC含量,一定程度上减轻巨噬细胞的泡沫化程度,推测可能与其抑制巨噬细胞上SR-B1受体功能从而抑制细胞对胆固醇摄取,或是通过增强巨噬细胞上ABCA1转运体的功能而促进了细胞内胆固醇的外流有关,或者是两者共同作用的结果.     

糖基化LDL增加胞浆钙浓度及脂质沉积

观察了糖基化低密度脂蛋白(glc-LDL)与人单核巨噬细胞相互作用时细胞内钙离子浓度及脂质代谢的改变。胞桨内游离钙离子浓度较正常LDL组升高(P<0.05),细胞结合、摄入和降解glc-LDL均较正常LDL升高,结合glc-LDL具饱和趋势,细胞总胆固醇含量增加(P<0.05)。提示人单核巨噬细胞代谢glc-LDL途径与正常LDL不同,细胞表面可能存在糖基化LDL受体,此过程伴脂质沉积和钙质积聚,使巨噬细胞易变为泡沫细胞,可能为糖尿病患者易患动脉粥样硬化的原因之一。     

巨噬细胞内脂质代谢及泡沫细胞形成机制的研究进展

动脉粥样硬化是以动脉内膜下胆固醇积聚为特征的慢性疾病。泡沫细胞是构成动脉粥样斑块的主要成分,大多由于巨噬细胞内脂质代谢紊乱引起。巨噬细胞通过胞饮、清道夫受体介导的方式吞噬胞外胆固醇,在胆固醇酰基转移酶1(ACAT1)和中性胆固醇酯水解酶(nCEH)作用下维持细胞内脂质平衡,多余的胆固醇可以通过ATP结合盒转运体A1(ABCA1)、ATP结合盒转运体G1(ABCG1)和清道夫受体B1(SR-B1)排出。该文介绍巨噬细胞内胆固醇摄取、酯化水解和外溢过程,以及泡沫细胞形成的机制。     

NO/PKG对THP-1巨噬细胞ABCA1基因mRNA表达和胆固醇含量的影响

目的:探讨THP-1巨噬细胞泡沫化过程中NO/PKG的变化,以及NO/PKG对THP-1巨噬细胞ATP结合盒转运体A1(ABCA1)基因mRNA表达和胆固醇含量的影响。方法:THP-1细胞诱导分化为巨噬细胞,用氧化低密度脂蛋白(ox-LDL)处理,油红O染色观察巨噬细胞脂滴,酶标仪测定一氧化氮(NO)的释放;用一氧化氮供体L-精氨酸和硝普钠(SNP)、乙二醇二乙醚二胺四乙酸(EGTA)、PKG激动剂处理巨噬细胞,RT-PCR法测定细胞ABCA1基因mRNA的表达,高效液相色谱法(HPLC)测定细胞内胆固醇的含量变化。结果:ox-LDL可导致THP-1巨噬细胞脂质的蓄积和NO释放的增加,实验组NO释放量较对照组显著升高(P<0.05),实验组中50mg/L组、100mg/L组、200mg/L组与25mg/L组相比显著升高(P<0.05)。用PKG激动剂处理巨噬细胞后促进ABCA1基因mRNA表达上调(P<0.05);用PKG激动剂、L-精氨酸、SNP处理后的巨噬细胞内胆固醇较对照组显著减少(P<0.05)。EGTA能显著增加细胞内胆固醇含量(P<0.05)。结论:NO/PKG能降低细胞内胆固醇,其机制可能是PK...     

Tim-3通过胆固醇酯水解酶影响巨噬细胞泡沫化过程的机制

目的观察Tim-3是否通过调节巨噬细胞内胆固醇脂水解酶(CEH)的表达干扰泡沫化细胞的形成,进而影响动脉粥样硬化的发生发展。方法 Western印迹检测CEH蛋白的表达;液体闪烁计数测定THP-1巨噬细胞内胆固醇流出情况;HPLC检测胞内脂质含量;油红O染色显示胞内脂滴情况;ELISA检测肿瘤坏死因子(TNF)-α、MIF、白细胞介素(IL)-10的分泌情况。结果 Ad-Tim-3组细胞中CEH的表达被明显抑制,胞内胆固醇流出减少,胞内总胆固醇(TC)、胆固醇酯(CE)及游离胆固醇(FC)的含量明显增加,TNF-α和MIF分泌增多,IL-10的分泌减少;Ad-CEH组和Ad-Tim-3+Ad-CEH组细胞中CEH的表达水平被明显增强,胞内胆固醇流出增加,胞内TC、CE及FC的含量明显减少,TNF-α和MIF分泌减少,IL-10分泌增多。结论 Tim-3可以通过增强巨噬细胞内CEH的活性抑制巨噬细胞向泡沫细胞的转化。     

巨噬细胞内胆固醇平衡机制研究进展

巨噬细胞内脂质含量增多形成泡沫细胞是动脉粥样硬化早期病变的特征变化之一.巨噬细胞可以通过CD36和清道夫受体A-Ⅰ等膜受体摄入胆固醇,同时通过清道夫受体B-Ⅰ、ABC家族等逆转运膜受体将胆固醇逆转运出细胞,从而维持细胞内胆固醇平衡,阻止其在细胞内堆积形成泡沫细胞.本文对巨噬细胞内与胆固醇平衡机制做一综述.     

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.     

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.     

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.     

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.