甲状腺功能减退大鼠心肌抗氧化能力及Na+-K+-ATP酶α1亚基mRNA表达的研究

采用低碘饮食建立甲状腺功能减退(甲减)动物模型,观察心肌抗氧化能力及Na+-K+-ATP酶α1亚基mRNA的变化,结果显示甲减大鼠心肌抗氧化能力下降,导致心肌过氧化损伤,心肌细胞萎缩,心脏内膜软骨化生,膜上参与代谢的ATP酶活性降低,Na+-K+-ATP酶α1亚基mRNA的表达下降.     

大鼠心肌缺血再灌注损伤对心肌细胞膜Na~+-K~+-ATP酶亚基基因表达的影响与意义

目的 观察心肌缺血再灌注损伤大鼠心肌组织内洋地黄素水平、ATP酶活性、线粒体Ca2 浓度以及Na -K -ATP酶各亚基基因表达的改变,探讨内洋地黄素在心肌缺血再灌注损伤细胞内钙超载中的可能作用及其机制.方法 32只雄性SD大鼠随机分成假手术组,心肌缺血再灌注组,生理盐水组,维拉帕米组4组,每组8只.取缺血区左心室心肌检测心肌匀浆内洋地黄素水平、心肌细胞膜Na -K -ATP酶和Ca2 -Mg2 -ATP酶活性、线粒体Ca2 浓度;分别采用RT-PCR及Western bloting方法检测心肌Na -K -ATP酶α1、α2、α3和β1亚基mRNA及蛋白水平基因表达的改变.结果 心肌缺血再灌注时,心肌组织内洋地黄素水平明显升高,心肌细胞膜Na -K -ATP酶和Ca2 -Mg2 -ATP酶活性显著下降,线粒体Ca2 浓度升高,Na -K -ATP酶α1、α2、α3和β1亚基mRNA及蛋白水平基因表达均明显下降;维拉帕米预处理除显示降低线粒体Ca2 浓度外,对其它各项指标无明显影响.结论 心肌缺血再灌注能促进心肌内洋地黄素分泌增加,后者可能通过影响心肌细胞膜上的Na -K -ATP酶α1、α2、α3和β1亚基基因表达,抑制Na -K -ATP酶活性,导致线粒体内Ca2 超载,从而介导心肌缺血再灌注损伤.确切的作用机制有待于更深入研究.     

羟自由基诱导心肌细胞损伤时ATP酶等变化

目的　探讨外源性羟自由基诱导乳鼠心肌细胞损伤的作用机理。方法　采用 Fe SO4 / H2 O2 产生系统 ,羟自由基诱导心肌细胞损伤 ,观察乳鼠心肌细胞内 Na+、K+ - ATP酶 ,Ca2 +、Mg2 + - ATP酶和丙二醛 (MDA)含量及其上清液中乳酸脱氢酶 (L DH)与一氧化氮 (NO)含量变化。结果　心肌细胞中 Na+、K+ - ATP酶 ,Ca2 +、Mg2 + - ATP酶减少 ,MDA含量增加 ,与对照组相比较 ,具有显著性差异 (P<0 .0 1,P<0 .0 5 ,P<0 .0 1) ;上清液中 L DH和 NO漏出增加 ,与对照组相比较 ,均具有显著性差异 (P<0 .0 1)。结论　羟自由基诱导心肌细胞中 Na+ 、K+ - ATP酶 ,Ca2 + 、Mg2 + - ATP酶减少 ,MDA及其上清液中 L DH和 NO漏出增加。从而揭示外源性羟自由基可能通过增加膜脂质过氧化 ,引起 ATP酶失活及膜结构破坏等 ,是导致心肌细胞死亡的机理之一     

1型糖尿病神经病变基因学研究进展

近年研究发现1型糖尿病神经病变是一种多基因病,其发生、发展存在着遗传倾向性,目前已发现主要与线粒体DNA突变,营养因子相关的早期基因表达延迟,醛糖还原酶、超氧化物歧化酶基因、Na+/K+ATP酶ATP1-A1基因多态性,丝裂素活化蛋白激酶基因,感觉神经元的神经丝和微管蛋白mRNA表达降低有关。一氧化氮合酶基因与神经病变的关系比较复杂,有待进一步研究。     

Aβ_(1～42)及二氮嗪预处理对神经细胞Na~+-K~+-ATP酶β亚基蛋白表达的影响

目的探讨Aβ1~42及二氮嗪预干预对神经细胞Na+-K+-ATP酶β亚基蛋白表达的影响。方法原代培养大鼠皮层海马神经细胞,随机分为空白对照组、Aβ1~42组(2μmol/L)、二氮嗪(50μmol/L)预处理1 h后Aβ1~42组、单独二氮嗪预处理组,各组又分为24、72 h两个时间点,采用免疫荧光及免疫印迹法检测干预后不同培养时间细胞Na+-K+-ATP酶β亚基蛋白表达水平的变化。结果免疫荧光显示:Aβ1~42作用细胞72 h降低了Na+-K+-ATP酶β亚基荧光强度;而经二氮嗪预处理后Aβ1~42作用72 h,与单独Aβ1~42组相比较荧光强度有所增强。Western印迹显示:二氮嗪预处理神经细胞1 h协同Aβ1~42作用24 h后及单独二氮嗪组Na+-K+-ATP酶β亚基的蛋白表达明显低于对照组及单独Aβ1~42组(P0.01)。Aβ1~42作用神经细胞72 h后,Na+-K+-ATP酶β亚基蛋白表达较对照组显著降低(P0.05);二氮嗪预处理1h协同Aβ1~42共同作用于神经细胞72 h后,与单独Aβ1~42组相比较,增加了Na+-K+-ATP酶β亚基蛋白表达量(P0.05)。结论 Aβ1~42作用72 h,Na+-K+-ATP酶β亚基蛋白表达量降低,二氮嗪预处理1 h协同Aβ1~42共同作用于神经细胞72 h,Na+-K+-ATP酶β亚基蛋白表达量升高。     

茜草多糖对衰老模型小鼠心肌线粒体酶活性影响的实验研究

目的探讨茜草多糖对衰老小鼠心肌线粒体酶活性的影响。方法通过建立D半乳糖人工致衰小鼠模型,测定心肌线粒体超氧化物歧化酶(SOD),Na+K+ATP酶和Ca2+ATP酶的活性。结果衰老模型组SOD、Na+K+ATP酶和Ca2+ATP酶的活性均明显降低;茜草多糖可升高衰老模型组SOD、Na+K+ATP酶和Ca2+ATP酶活性(P<0.05,P<0.01)。结论茜草多糖对衰老模型小鼠心肌线粒体有保护作用。     

Nesfatin-1对离体胃黏膜细胞胃酸分泌的影响

目的:研究nesfatin-1对离体培养的大鼠胃黏膜酸分泌的影响,探讨nesfatin-1对H+/K+-ATP酶mRNA及蛋白表达的影响.方法:酶解法分离大鼠胃黏膜细胞,细胞免疫荧光检测法鉴定细胞.用不同浓度的nesfatin-1(10-4-10-1μmol/L)对胃黏膜细胞进行处理0、1、2、3、4h,设立空白对照组,以14C-氨基比林摄取为酸分泌指标,检测nesfatin-1对大鼠离体的胃黏膜细胞酸分泌的影响.用RT-PCR法及Western印迹法检测nesfatin-1对胃黏膜细胞H+/K+-ATP酶alpha(α)亚基和beta(β)亚基mRNA及蛋白表达的影响.结果:Nesfatin-1在10-1μmol/L浓度下,在1、2h能够抑制离体培养的大鼠胃黏膜细胞的酸分泌.Nesfatin-1(10-1μmol/L)在1、2、3h均能够抑制H+/K+-ATP酶α亚基mRNA表达水平;在1、2h能够抑制H+/K+-ATP酶β亚基mRNA表达水平,分别与对照组相比,差异有统计学意义(均P<0.01).Nesfatin-1(10-4-10-1μmol/L)作用胃黏膜细胞2h时,呈剂量依赖性抑制α亚基和β亚基mRNA表达水平,分别与对照组相比,差异有统计学意义(均P<0.01).Nesfatin-1(10-1μmol/L)在1、2、3h能够抑制α亚基蛋白表达水平;在2、3h能够抑制β亚基蛋白表达水平,分别与对照组相比,差异有统计学意义(均P<0.01).Nesfatin-1(10-3-10-1μmol/L)作用胃黏膜细胞2h时,呈剂量依赖性抑制α亚基和β亚基蛋白表达水平,与对照组相比,差异有统计学意义(均P<0.01).结论:Nesfatin-1能抑制离体培养的大鼠胃黏膜细胞的酸分泌,有可能是通过下调H+/K+-ATP酶α亚基和β亚基的mRNA及蛋白表达的水平影响酸分泌.     

洛沙坦对甲状腺素诱导的大鼠心肌肥厚的影响

目的 :研究血管紧张素 1型受体拮抗剂洛沙坦对甲状腺素诱导的心肌肥厚的影响。方法 :SD大鼠 ip左甲状腺素 0 .5 m g· kg- 1 · d- 1 × 1 0 d,造成心肌肥厚模型。同时洛沙坦 ig 40 mg· kg- 1 · d- 1 × 1 0 d。观察心重指数 ,心肌胶原浓度 ,心肌细胞直径 ,心肌胶原容积分数 ;心肌肌球蛋白 ATP酶 ,细胞膜和线粒体 Na ,K - ATP酶 ,Ca2 - ATP酶。结果 :洛沙坦能阻止心肌肥厚的发生 ,降低心重指数 ,减少胶原合成 ,提高肌球蛋白 ATP酶活力及细胞膜和线粒体 Na ,K - ATP酶 ,Ca2 - ATP酶活力。结论 :洛沙坦可防止甲状腺素诱导的心肌重塑     

伴恶性心律失常的Brugada综合征SCN1B基因突变分析1例

<正>Brugada综合征是遗传性心律失常疾病,主要由编码传导去极化INa电流的Nav1.5钠离子通道α-亚基的SCN5A基因突变所致的功能丧失引起,其他突变基因包括编码Nav1.5钠离子通道β亚基的SCN1B和SCN3B,编码传导去极化ILCa电流的Cav1.2离子通道α-亚基的CACNA1C基因,基因突变导致钠离子或钙离子内流减少,或钾离子外流[1]。     

与糖尿病神经病变相关基因的研究进展

糖尿病神经病变 (DN)与多种危险基因有关 ,已发现DN与醛糖还原酶、对氧磷脂酶基因多态性 ;一氧化氮合酶 (NOS)、有丝分裂原活性蛋白激酶基因表达增加 ;NOS基因的第 7个外显子突变为Asp( 894G→T)及Na+/K+ ATP酶ATP1A1基因的变异 ;感觉神经元的细胞骨架蛋白质mRNA表达降低等有关 ,而DN时抗氧化酶的基因表达没有减少 ,增加神经营养因子的表达可以治疗DN。     

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.