溶血卵磷脂对载脂蛋白E基因缺陷小鼠腹腔巨噬细胞源泡沫细胞胆固醇外流的影响

以载脂蛋白E基因缺陷小鼠腹腔巨噬细胞源泡沫细胞为研究对象，观察溶血卵磷脂对泡沫细胞胆固醇外流的影响以及初步探讨其机制。分离正常及载脂蛋白E基因缺陷小鼠腹腔巨噬细胞，以乙酰化低密度脂蛋白负载形成巨噬细胞源泡沫细胞，分别以溶血卵磷脂及载脂蛋白AI作为诱导物，观察其胆固醇外流情况。结果发现，溶血卵磷脂能引起正常组小鼠腹腔巨噬细胞源泡沫细胞胆固醇外流，且呈剂量效应关系，但载脂蛋白E基因缺陷小鼠组未明显胆固醇外流；载脂蛋白AI能引起两组胆固醇外流，且外流量显著高于溶血卵磷脂。结果提示，溶血卵磷脂能促进巨噬细胞源泡沫细胞胆固醇外流，可能主要是通过载脂蛋白E途径来进行。     

花色苷对小鼠腹腔巨噬泡沫细胞胆固醇外流的影响及其分子机制探讨

目的 研究花色苷对小鼠腹腔巨噬泡沫细胞胆固醇外流的影响,探讨 花色苷抗动脉粥样硬化的分子机制。方法 以50μg／ml氧化型低密度脂蛋白培养小鼠腹腔巨噬细胞24h形成巨噬泡沫细胞。用1、10、100I．Lmol／L矢车菊定-3-葡萄糖苷（Cy-3-g）和芍药定-3-葡萄糖苷（Pn-3-g）分别培养巨噬泡沫细胞,酶学荧光法检测培养液中胆固醇含量,用定量PCR和激光共聚焦显微镜检测三磷酸腺苷结合盒转运体A1（ABCA1）的表达。结果 花色苷Cy-3-g和Pn-3-g能够促进巨噬泡沫细胞胆固醇外流,这一作用存在时间和剂量一依赖关系。花色苷还能促进巨噬泡沫细胞ABCA1 mRNA和蛋白的表达,ABCA1抑制剂4,4’-二异硫氰酸二丙乙烯12,2’-二磺酸能够阻断花色苷诱导巨噬泡沫细胞胆固醇外流。结论 花色苷Cy-3-g和Pn-3-g通过调控ABCA1的表达从而促进巨噬泡沫细胞胆固醇外流。     

小檗碱调节肝X受体α去乙酰化促进THP-1

目的 观察小檗碱对THP-1巨噬细胞源性泡沫细胞ATP结合盒转运体A1(ABCA1)表达及其细胞内胆固醇流出的影响,并探讨肝x受体α(LXR-α)去乙酰化在此过程中的作用.方法 用不同浓度的小檗碱(0、5、10、20 μmol/L)处理THP-1巨噬细胞源性泡沫细胞24 h,或以20 μmol/L小檗碱处理THP-1巨噬细胞源性泡沫细胞不同的时间(0、6、12、24 h).采用Western Blot检测ABCA1、LXR-α和乙酰化LXR-α的蛋白表达,液体闪烁计数法观察细胞内胆固醇的流出,高效液相色谱法测定细胞内胆固醇浓度.结果 与对照组比较,小檗碱呈浓度(0～20 μmol/L)和时间依赖性(0～24 h)上调巨噬细胞源性泡沫细胞ABCA1的表达和下调乙酰化LXR-α的表达,增加THP-1巨噬细胞源性泡沫细胞内胆固醇的流出,减少细胞内胆固醇的含量.上述效应在20 μmol/L小檗碱处理THP-1巨噬细胞24 h后达到最大值.结论 小檗碱能上调THP-1巨噬细胞源性泡沫细胞ABCA1的表达,并促进细胞内胆固醇流出,这种效应与调节LXR-α乙酰化有关.     

心肌细胞钙离子通道

钙离子通道(简称钙通道)几乎存在所有可兴奋细胞.钙通道的重要功能就是调节细胞内钙离子浓度.正常静息条件下,心肌细胞内的钙离子浓度很低(10～300 nmol/L),在兴奋条件下其生理浓度可高达 1μmol/L 以上.升高的细胞内钙离子一方面直接引起心肌收缩;另一方面也参与其他多种钙依赖蛋白酶活性的调节,起到第二信使作用.心肌细胞钙通道主要分为电压门控型钙通道和钙释放通道两种.笔者就它们的结构、功能及门控特点作一简介.     

PPARs激动剂对RAW264.7巨噬细胞源性泡沫细胞内胆固醇含量的影响

目的 探讨PPARs激动剂吡格列酮对RAW264.7巨噬细胞源性泡沫细胞内胆固醇含量的影响.方法 首先用50 mg/L氧化型低密度脂蛋白（ox-LDL）将体外培养的RAW264.7巨噬细胞诱导分化为泡沫细胞,然后进行油红O染色,并在光镜下鉴定泡沫细胞形态及变化;再以不同浓度吡格列酮（0 μmol/L、5 μmol/L、10μmol/L、20 μmol/L、30 μmol/L）作用泡沫细胞24h,以30 μmol/L的吡格列酮作用0h、6h、12h、24 h、48 h;最后酶法检测泡沫细胞内胆固醇的含量.结果 ①50 mg/Lox-LDL诱导巨噬细胞48 h后分化为泡沫细胞.②与对照组相比,不同浓度吡格列酮作用后泡沫细胞内胆固醇含量均减少,差异有统计学意义（P＜0.01）,且呈剂量依赖性.③与对照组相比,30 μmol/L的吡格列酮作用6h、12 h、24 h、48 h后,泡沫细胞内胆固醇含量均减少,差异有统计学意义（P＜0.01）,且呈时间依赖性.结论 PPARs激动剂吡格列酮能够减少泡沫细胞内胆固醇含量,且呈剂量和时间依赖性。     

松龄血脉康对THP-1源性泡沫细胞ABCA1蛋白表达及细胞内胆固醇含量的影响

目的 观察松龄血脉康对THP-1源性泡沫细胞腺苷三磷酸结合盒转运体A1(ABCA1)蛋白表达及细胞内胆固醇含量的影响及其防治动脉粥样硬化(AS)的可能机制.方法 培养THP-1细胞,160 nmol/L佛波脂(PAM)使之巨噬化,用50 mg/L氧化型低密度脂蛋白使巨噬细胞形成泡沫细胞.0.81 mg/L松龄血脉康、10 μmol/L罗格列酮分别和泡沫细胞孵育6、12、24 h;0.40、0.81、1.6 mg/L的松龄血脉康、1、10、20 μmol/L的罗格列酮与泡沫细胞孵育24 h.用流式细胞技术检测ABCA1蛋白表达的水平,并测定各组细胞内胆固醇含量.结果 松龄血脉康组、罗格列酮组均增加ABCA1蛋白的表达,而细胞内胆固醇含量减少,与对照组相比,均有显著性差异(P＜0.05),且有浓度、时间依赖性.松龄血脉康组与罗格列酮组无显著性差异(P>0.05).结论 松龄血脉康具有与罗格列酮增加ABCA1蛋白及降低胆固醇含量相似的作用.增加ABCA1蛋白表达,降低细胞内胆固醇含量可能是中药松龄血脉康抗AS的机制之一.     

钙拮抗剂在肝脏疾病中的作用

钙离子作为细胞内第二信使,在维持细胞增殖、分裂、运动、能量代谢、氧的需要、钙依赖蛋白激酶和磷脂酶的激活以及神经递质的释放中发挥着重要作用。越来越多的研究发现,组织细胞的损伤与细胞内钙过负荷有密切的关系。正常情况下,细胞内外液中钙浓度保持着相当稳定。一旦受到外源性刺激,Ca~(2+)即可通过胞膜上钙通道流入胞内,与其受体钙调蛋白(CaM)结合,产生一系列酶促反应,调节各种细胞功能。而钙通道阻滞剂因阻滞了钙通道,限制了     

心肌钙预适应的研究进展

钙预适应作为心脏内源性的保护机制之一涉及细胞内多种复杂的变化。预适应过程中升高的钙离子作为第二信使,激活蛋白激酶C,活化的蛋白激酶C使心肌细胞膜ATP敏感性钾通道和线粒体ATP敏感性钾通道开放,产生对缺血再灌注心肌的保护作用。     

Nε-羧甲基赖氨酸通过RAGE促进平滑肌细胞源性泡沫细胞形成

目的研究Nε-羧甲基赖氨酸(CML)对平滑肌细胞泡沫化中脂质外流的影响,探讨其在促进平滑肌细胞泡沫化中的作用和机制。方法使用组织贴块法从C57BL/6J小鼠主动脉中提取原代血管平滑肌细胞并进行鉴定;将第3~9代的原代平滑肌细胞分为对照组,氧化型低密度脂蛋白(ox-LDL)(50 mg/L)模型组,1、10、100μmol/L的CML与ox-LDL共刺激组,通过NBD-胆固醇流出实验检测CML对泡沫细胞胆固醇流出率的影响,通过胆固醇含量测定试剂盒测定细胞内总胆固醇(TC)、游离胆固醇(FC)和胆固醇酯(CE)水平;将原代血管平滑肌细胞分为四组:对照组、ox-LDL模型组、ox-LDL+CML组、RAGE siRNA沉默组(ox-LDL+CML+siRAGE组)并进行刺激,通过Western blot检测糖基化终末产物受体(RAGE)和胆固醇流出调节子ABCA1的表达;通过油红O染色和油红萃取实验检测各组平滑肌细胞泡沫化程度。结果与对照组相比,不同浓度CML明显升高平滑肌细胞内TC、CE和FC的含量;胆固醇流出实验表明胆固醇流出率随CML浓度升高而降低;Western blot实验表明与对照组相比,加入CML后RAGE明显升高,ABCA1明显降低,ox-LDL+CML+siRAGE组RAGE的表达降低,并且ABCA1降低水平减少;油红O染色显示ox-LDL能够促使平滑肌细胞内脂质蓄积,CML能够增强其作用,抑制RAGE表达后CML作用减弱。结论 CML通过RAGE抑制脂质外流,促进平滑肌细胞源性泡沫细胞形成。     

小鼠胰腺腺泡细胞系MPC-83中功能性G蛋白偶联受体的缺失

目的:研究小鼠胰腺肿瘤细胞系MPC-83细胞中功能性G蛋白偶联受体(G protein-coupled receptor,GPCR).方法:培养小鼠胰腺肿瘤细胞系MPC-83细胞,检测其刺激前后胞质游离钙离子浓度的变化.结果:ACh 25 nmol/L刺激新鲜分离的正常小鼠胰腺腺泡细胞,胞质钙离子浓度发生规则、振荡样升高;CCK5pmol/L具有类似作用.GPCR激动剂CCK 1 μmol/L、VP 1 μmol/L、P 物质5 μmol/L、组织氨10 μmol/L、PE 10μmol/L和ACh 100 μmol/L分别刺激MPC-83细胞,胞质钙离子没有发生任何增加.地塞米松100 nmol/L与MPC-83细胞共孵育72h,MPC-83细胞增殖速度明显降低,但GPCR配体CCK、VP、P物质仍然不引起胞质钙离子浓度的增加.结论:从昆明小鼠胰腺外分泌部肿瘤分离出来的胰腺腺泡细胞系MPC-83,正常的G蛋白偶联受体完全缺失,处于极度去分化状态.     

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.