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1.
实验观察了食饵性兔动脉粥样硬化形成过程中血小板胞浆游离钙[Ca^2+]i、血清钙、红细胞膜钙泵即Ca^2-Mg^2+-ATPase的活性,主动脉收缩性的变化,与以照组比较结果表明:(1)高脂兔血小板[Ca^2+]i水平增高,红细胞膜Ca^2+-Mg^2+-ATPase活性及主动脉收缩性降低;(2)主动脉组织光镜可见高脂兔主动脉中层有大量钙沉积;(3)扫描电镜可见血小板粘附于内皮细胞表面。 相似文献
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Ca^2+与肝细胞增殖 总被引:2,自引:0,他引:2
王炳芳 《国外医学:消化系疾病分册》1994,14(2):80-82
本文综述了Ca^2+作为第二信使在肝细胞增殖中的信息传递作用。细胞内Ca^2+([Ca^2+]i)浓度升高是通过生长因子和癌蛋白等与细胞膜的相应体结合,启动磷酯酰肌醇系统,进一步作用于细胞内钙库使其释放,或通过激活细胞膜Ca^2+通道使Ca^2内流增加,[Ca^2+]i升高后,激活一些酶,使底物蛋白磷酸化,最后交替信息传到核内,促进DNA复制细胞增殖分裂。本文并对Ca^2+与肝再生,肝纤维化和肝癌 相似文献
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血小板衍生生长因子和钙拮抗剂对大鼠肝细胞胶原合成及?… 总被引:2,自引:0,他引:2
目的:观察血小板衍生生长因子(Platelet-derivdegrowthfactor,PDGF)和钙拮抗剂(Calciumantagonist,Ga-A)对原代培养大鼠肝细胞胶原合成及细胞内游离钙浓度(Ca^2+)i)的影响,方法:应用^3H-脯氨酸掺入率和Fura-2/AM荧光示踪法分别测定细胞内胶原含量及(Ca^2+)结果:PDGF能促进细胞内胶原合成,提高肝内(Ca^2+)i且与浓度呈正相 相似文献
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巨噬细胞在泡沫细胞化过程中的Ca2+变化 总被引:2,自引:1,他引:1
我室曾用C_(57)BL/6J品系小鼠腹膜巨噬细胞与10mg·L ̄(-1)氧化低密度脂蛋白孵育4天,建立了出现在早期动脉粥样硬化损伤中的巨噬细胞源性泡沫细胞的病理细胞模型,本文报道应用Ca ̄(2+)荧光指示剂技术及NADH氧化偶联差光谱变化的分析方法,检测了前述培养的泡沫样细胞的胞浆Ca ̄(2+)水平及膜上Ca ̄(2+)依赖性ATP酶活性。发现泡沫样细胞内的Ca ̄(2+)水平为对照组细胞的2.7倍,膜上Ca ̄(2+)依赖性ATP酶活性为后者的24%。实验结果提示,在巨噬细胞源性泡沫细胞的形成过程中,伴随着缓慢的Ca ̄(2+)内流或释放,这可能与膜上Ca ̄(2+)通道的持续开放及后期Ca ̄(2+)依赖性ATP酶的钝化有关。 相似文献
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钙在CVB3诱导大鼠心肌细胞凋亡中的作用 总被引:1,自引:0,他引:1
目的 探讨细胞内游离钙〔Ca^2+〕i在柯萨奇病毒B3(CVB3)诱导培养心肌细胞凋亡中的作用。方法 DNA裂点检测法(3’-末端标记)及透射电镜检测细胞凋亡。Fluo3-AM负主肌细胞,共聚焦显微镜观察〔Ca^2+〕i荧光强度变化。结果感染24h心肌细胞内CVB3滴度达峰值。感染10h未见凋亡的心肌细胞,17、24和36h凋亡细胞分别为5%、60%和90%,感染17h心肌〔Ca^2+〕i浓度达 相似文献
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甲基莲心碱在体外对抗脂蛋白的氧化 总被引:9,自引:2,他引:7
为探讨甲基莲心碱能否对抗脂蛋白的氧化,本文检测了甲基莲心碱对于Cu^2+介导低密度脂蛋白和极低密度脂蛋白氧化修饰的效应。结果发现,甲基莲心碱能抑制低密度脂蛋白和极低密度脂蛋白的硫代巴比妥酸反应物质的生成,还能抑制Cu^2+介导的极低密度脂蛋白电泳迁移率的增加。用甲基莲心碱保护的低密度和极低密度脂蛋白引起巨噬细胞内胆固醇和甘油三酯的推积均低于相应的未保护脂蛋白。结果提示,甲基莲心碱能够在体外对抗Cu 相似文献
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兔脑缺血脑组织Ca^2+和血小板胞浆游离Ca^2+的动态变化 总被引:3,自引:0,他引:3
目的探讨Ca2+在缺血性脑损伤中所起的作用。方法Fura-2荧光比值法测兔大脑中动脉阻断后不同时间血小板胞浆游离Ca2+浓度(〔Ca2+〕i);邻甲酚酞络合指示剂自动分析法测脑组织Ca2+含量。结果兔脑缺血4小时即有血小板〔Ca2+〕i明显增加(P<0.001),24及48小时血小板〔Ca2+〕i持续升高;缺血48小时,缺血区脑组织水、Ca2+含量明显升高(P<0.001)。结论脑缺血的发生、发展与Ca2+大量病理性流入关系密切,Ca2+超载是导致神经细胞死亡的重要因素。 相似文献
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槲皮素对家兔主动脉血管平滑肌细胞胞内游离钙浓度的影响 总被引:9,自引:0,他引:9
目的:探讨槲皮素(Que)对智力这平滑肌细胞胞内游离钙浓度(〖Ca^2+)〗i的影响。方法:采用新一代钙荧光探剂Fluo-3/AM检测Que对培养的兔主动脉血管平滑肌细胞(ASMC)〖Ca^2+〗i在高K^+、去甲肾上腺素(NE)、血管紧张素Ⅱ(AngⅡ)刺作用下的改变,并与Verapamil进行对照研究。结果:Que(10^-6、10^-4mol/l)呈剂量依赖性抑制高K^+去极化引起的〖Ca^ 相似文献
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氨氯地平对高血压患者淋巴细胞胞内游离钙,血浆血管紧张素Ⅰ和… 总被引:2,自引:0,他引:2
测定ⅠⅡ期高血压病患者给予氨氯地平治疗四周前后平均动脉压、淋巴细胞胞浆游离钙、血管紧张素及左室舒张功能指标。结果显示:(1)治疗后MAPCa^2+i,AngⅠ显著下降;(2)左室舒张功能指标显著改善;(3)治疗后,Ca^2+i下降幅度与MAP下降幅度呈正相关。 相似文献
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维拉帕米对心肌细胞肥大的影响 总被引:3,自引:0,他引:3
目的研究维拉帕米对心肌细胞肥大的影响及其机制。方法测定培养的心肌细胞[Ca2+]i和3H-亮氨酸(3H-Leu)参入。结果2×10-7mol/L维拉帕米对培养的心肌细胞[Ca2+]i和3H-Leu参入无明显影响(P>0.05),2×10-6~10-5mol/L维拉帕米则可显著抑制培养的心肌细胞[Ca2+]i和3H-Leu参入。与对照组相比,心肌细胞[Ca2+]i和3H-Leu参入分别减低10%~27%(P<0.01)和12%~25%(P<0.05)。结论维拉帕米可以抑制培养的心肌细胞肥大,作用机制可能与其降低细胞内游离钙和细胞收缩性有关。 相似文献
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The immunoneuroendocrine role of melatonin 总被引:19,自引:0,他引:19
Georges J. M. Maestroni 《Journal of pineal research》1993,14(1):1-10
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. 相似文献
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Changes in connexin43, the gap junction protein of astrocytes, during development of the rat pineal gland 总被引:2,自引:0,他引:2
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. 相似文献
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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. 相似文献
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Martinez-Cecilia D Arjona-Sanchez A Gomez-Alvarez M Torres-Tordera E Luque-Molina A Valenti-Azcarate V Briceno-Delgado J Padillo FJ Lopez-Cillero P Rufian-Pena S 《World journal of gastroenterology : WJG》2008,14(12):1949-1951
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. 相似文献
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H.P.J.M. Noteborn P.P. van Balen A.A. van der Gugten I.C. Hart I. Ebels C.A. Salemink 《Journal of pineal research》1993,14(1):11-22
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 Mr 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 (Ka 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 Mr 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. 相似文献
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Gary S. Goldberg B.A. Bruce A. Orkin M.D. Lee E. Smith M.D. 《Diseases of the colon and rectum》1994,37(5):439-443
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. 相似文献