氯沙坦和卡维地洛对缺血再灌注心肌细胞凋亡的影响

目的 :研究氯沙坦和卡维地洛对缺血再灌注心肌细胞凋亡的影响 ,比较氯沙坦和卡维地洛对缺血再灌注心肌损伤的保护作用。方法 :结扎Wistar大鼠左冠状动脉前降支 ,建立大鼠缺血再灌注动物模型 ,采用原位末端标记细胞凋亡法检测心肌细胞凋亡 ,并利用光学显微镜进行细胞计数。结果 :单纯缺血 再灌注组心肌细胞凋亡数较假手术组明显增多 (37.5 3± 9.2 2 /视野∶0 .18± 0 .0 9/视野 ,P <0 .0 5 ) ,氯沙坦和卡维地洛组心肌细胞凋亡数分别为 8.74± 3.5 1/视野和 7.6 3± 4 .0 5 /视野 ,较单纯缺血 再灌注组明显减少 (P <0 .0 5 ) ,氯沙坦和卡维地洛两组间无明显区别 (P >0 .0 5 )。结论 :氯沙坦和卡维地洛对缺血再灌注心肌细胞损伤具有相似的保护作用 ,可明显减少缺血再灌注心肌细胞凋亡     

氧化苦参碱对豚鼠心室肌细胞膜L-型钙通道的影响

研究氧化苦参碱 (Oxy)对豚鼠心室肌细胞膜L 型钙通道的影响 ,探讨Oxy在离子通道水平的药理作用机制。用急性酶解法分离豚鼠心室肌细胞 ,应用膜片钳全细胞记录技术 ,观察不同浓度的Oxy对L 型钙通道的影响。结果 :用 0 .0 1 ,0 .1 ,1 ,1 0 μmol/L可浓度依赖性地增加L 型钙电流 (ICa L)。在 0 .1 μmol/L时 ,给药后电流密度增加约 31 %(P <0 .0 1 ) ,可使心肌细胞钙电流 电压曲线下移 ,但激活电位、峰电位及反转电位无改变 ;Oxy使激活曲线向负电位方向变化 ,半数激活电压增加 ;对失活曲线无明显影响 ,未改变ICa L失活特性。结论 :Oxy可浓度依赖性和电压依赖性地增加心肌细胞膜L 型钙通道电流     

人参皂甙Re对大鼠缺血再灌注心肌细胞凋亡及Fas基因表达的影响

目的 :观察人参皂甙Re(以下简称Re)对缺血再灌注心肌细胞凋亡及Fas基因表达的影响 ,探讨Re抑制心肌细胞凋亡的可能机制。方法 :结扎Wistar大鼠左冠状动脉前降支 ,建立大鼠缺血再灌注动物模型 ;采用透射电镜、缺口末端标记法检测心肌凋亡细胞 ,利用光学显微镜进行细胞计数 ;原位杂交及免疫组化分别检测Fas基因mRNA及蛋白的表达 ,并利用图像分析系统测量阳性表达区域平均光密度值 ,进行定量分析。结果 :①透射电镜发现缺血再灌注组缺血区出现心肌凋亡细胞 ,假手术组未发现心肌凋亡细胞 ;②缺血再灌注组心肌细胞凋亡数为 (134.4 5± 4 5 .6 1)个 /视野 ,Re治疗组细胞凋亡数 (90 .6 6± 19.2 2 )个 /视野 ,两组间差异有非常显著性意义 (P<0 .0 1) ;③原位杂交及免疫组化检测均发现Fas基因的表达缺血再灌注组较假手术组明显增加 (P <0 .0 1) ,Re治疗组较缺血再灌注组明显下降 (P <0 .0 5 )。结论 :心肌缺血再灌注诱导心肌细胞凋亡 ,Re治疗则可以显著减少缺血再灌注心肌细胞的凋亡。Re通过抑制Fas基因的表达而抑制心肌细胞凋亡     

高、低剂量极化液对缺血/再灌注心肌细胞凋亡及相关基因的影响

目的 :探讨高、低两种剂量葡萄糖 -胰岛素 -钾极化液 （GIK）对缺血 /再灌注 （MI/R）心肌超微结构 ,细胞凋亡及其相关基因的影响。方法 :制备兔MI/R模型 ,分别用生理盐水 ,低剂量极化液 （LGIK） ,高剂量极化液 （HGIK）干预分组。检验心肌组织SOD活性 ,原位末端标记 （TUNEL）法测定凋亡心肌细胞 ,免疫组化SP法测定Bcl 2 ,Fas的含量 ,在电镜下观察心肌细胞的超微结构。结果 :与对照组比较 ,HGIK组SOD活性增加 （P <0 .0 1） ,凋亡指数 （AI）和Fas含量减少 （P <0 .0 1） ,Bcl 2含量增加 （P <0 .0 1）。心肌细胞超微结构表现为损伤减轻。LGIK亦可增加SOD活性和Bcl 2含量 （P <0 .0 5 ） ,减少AI和Fas（P <0 .0 5 ）含量。结论 :GIK具有抗缺血 /再灌注损伤的作用 ,其机制可能是通过调节Bcl 2和Fas介导的心肌缺血 /再灌注细胞凋亡而实现。高剂量GIK对缺血 /再灌注心肌细胞的保护作用显著大于低剂量GIK（P <0 .0 5 ）。     

兔急性心肌梗死后梗死周边带心肌细胞L-型钙通道的变化

探讨L型钙通道在急性心肌梗死 (AMI)后室性心律失常发生中的作用及其机制。方法 :以开胸冠状动脉结扎法制备兔AMI模型 ,1周后处死动物分离心室肌细胞 ,采用全细胞膜片钳记录技术观察梗死周边缺血带心外膜心室肌细胞L型钙通道电流 (ICa L)的变化 ,以正常心肌ICa L为对照。结果 :AMI 1周时兔梗死周边区心室肌细胞L型钙电流受到抑制 ,其电流峰值由正常状态下的 - 5 .58± 1 .53pA/pF(对照组 ,n =1 0 )降至 - 3 .52± 0 .93pA/pF(AMI组 ,n=6) ,最大峰电流下降 2 9.1 % ,P <0 .0 5 ,I V曲线上移 ;其失活曲线左移 ,半数最大失活电位由 - 1 3 .1± 4 .2mV左移至 - 2 5 .9± 7.0mV ,P <0 .0 5 ,失活速度加快。结论 :AMI后 1周梗死周边带心外膜心室肌细胞L型钙通道受抑制 ,可能为AMI后室性心律失常发生的机制之一。     

外源性磷酸肌酸对缺血豚鼠心室肌细胞L型钙通道电流的影响

目的:观察不同浓度外源性磷酸肌酸(exogenous phosphocreatine,PCr)对豚鼠缺血心室肌细胞L型钙通道(ICa.L)电流的影响,探讨其治疗缺血性心力衰竭的电生理学机制。方法:单个心室肌细胞经酶解从豚鼠左心室获得,采用膜片钳全细胞模式记录ICa.L电流,通过灌注模拟缺血液并充以95%N2+5%CO2的混合气体建立缺血模型,将PCr加入模拟缺血液中分别配成5,10,20,30 mmol/L浓度。将细胞分成6组,分别予模拟缺血液,含有5,10,20,30mmol/L浓度PCr的模拟缺血液,台氏液灌流,后者充以95%O2+5%CO2的混合气体。10 min后记录各组的峰电流及电流密度。结果:与台氏液组相比,模拟缺血液组ICa.L峰电流密度降低(80.6±5.2)%(P0.05),含有5,10,20,30 mmol/L浓度PCr的模拟缺血液组ICa.L峰电流密度分别降低(53.8±6.7)%(P0.05);(41.8±8.2)%(P0.05);(38.1±7.4)%(P0.05);(36.6±9.7)%(P0.05)。10,20,30 mmol/L 3种浓度对ICa.L峰电流密度的影响无统计学差别。结论:PCr能明显增加缺血时受抑制的ICa.L峰电流及电流密度,这可能是其治疗缺血性心力衰竭的电生理学机制。PCr在低浓度(0～10 mmol/L)对ICa.L电流及电流密度的影响呈现明显的量效关系,浓度大于10mmol/L量效关系不明显。     

模拟缺血-再灌注对窦房结细胞起搏离子流的影响及K_(ATP)通道开放剂的干预作用

探讨模拟缺血 再灌注对窦房结细胞起搏离子流 (If)的影响及KATP通道开放剂Pinacidil的干预效果。分离乳鼠窦房结细胞 ,纯化培养 2天后进行实验。随机分为对照组、模拟缺血 再灌注组 (I/R)、KATP通道开放剂Pinacidil干预组 (P +I/R)及KATP通道阻断剂 5 HD干预组 (5 HD +P +I/R及 5 HD +I/R)。采用常规全细胞膜片钳技术及多导管灌流系统 ,测定各组细胞If 密度 ,并绘制If 激活曲线。结果 :①每个窦房结细胞均可记录到If 电流 ,在相同指令电压下 ,I/R组窦房结细胞If 密度值较对照组明显增加 (P <0 .0 1) ;而P +I/R组则较I/R组显著减小 (P <0 .0 1) ;5 HD +P +I/R及 5 HD +I/R两组又较P +I/R组明显增加 (P <0 .0 1) ,但与I/R组比较无显著差异。②与对照组比较 ,I/R组窦房结细胞的If 激活曲线发生右移 ,半数最大激活电压由 - 10 8.0± 12 .4mV变为 - 89.5± 7.2mV(P <0 .0 1) ;P +I/R组窦房结细胞If 激活曲线较I/R组左移 ,半数最大激活电压为 - 99.5± 10 .8mV(P <0 .0 5 ) ;KATP通道阻断剂 5 HD可阻断Pinacidil对If 激活曲线的影响。结论 :KATP通道开放剂Pinacidil可对抗模拟缺血 再灌注对窦房结细胞If 的影响 ,此有利于维持模拟缺血 再灌注时窦房结细胞离子稳态和电生理活动的相对稳定     

卡维地洛对大鼠缺血再灌注心肌细胞凋亡及基因表达的影响

目的 :研究卡维地洛对缺血再灌注心肌细胞凋亡及bcl 2、bax基因表达的影响 ,探讨卡维地洛抑制缺血再灌注心肌细胞凋亡的可能分子机制。方法 :结扎Wistar大鼠左冠状动脉前降支 (LAD) ,建立大鼠缺血再灌注动物模型。 30只大鼠分 3组 (每组 10只 ) :卡维地洛组 (卡维地洛治疗 )、缺血再灌注组和假手术组。用Tunnel法检测心肌细胞凋亡 ,并用光学显微镜进行细胞计数 ,免疫组化和原位杂交法检测bcl 2、bax基因表达 ,并利用图像分析系统检测二者的平均光密度值 (A值 ) ,进行定量分析。结果 :心肌细胞凋亡数在缺血再灌注组、假手术组和卡维地洛组分别为 36 .8± 9.0、0 .2± 0 .1和 9.5± 3.0 ,各组间差异有统计学意义 (P <0 .0 1)。缺血再灌注组、假手术组和卡维地洛组的bcl 2mRNAA值分别为 0 .0 6± 0 .0 1、0 .0 8± 0 .0 1和 0 .0 9± 0 .0 1,bcl 2蛋白平均A值分别为0 .0 8± 0 .0 2、0 .14± 0 .0 1和 0 .15± 0 .0 3,卡维地洛组与缺血再灌注组相比差异无统计学意义 (P >0 .0 5 ) ;缺血再灌注组bax蛋白的平均A值为 0 .13± 0 .0 2 ,假手术组为 0 .0 7± 0 .0 1,卡维地洛组为 0 .0 6± 0 .0 1,卡维地洛组与缺血再灌注组相比差异有统计学意义 (P <0 .0 5 ) ,bcl 2 /bax蛋白比值在缺血再灌注组、假手术组和卡     

乙酰胆碱诱发的豚鼠心室肌反跳作用研究

观察乙酰胆碱 (ACh)诱发的豚鼠心室肌肌力及钙电流的反跳作用 ,并探讨其作用机制。采用豚鼠离体左室乳头肌观察 1μmol/LACh单独对心室肌收缩力 (Fc)的影响及在 10nmol/L异丙肾上腺素 (Iso)存在时对Fc的影响 ,并应用膜片钳全细胞记录方法分别观察 1μmol/LACh和 1μmol/LACh +10nmol/LIso及迅速洗脱ACh对豚鼠心室肌细胞L型钙通道电流 (ICa L)的影响。结果 :1μmol/LACh对心室肌Fc有直接抑制作用 ,抑制率为 30 .8%± 10 .7%(P <0 .0 5 ) ,而快速洗脱ACh后 ,Fc反跳性增强了 2 5 .5 %± 10 .3% (n =7,P <0 .0 1)。而在应用 10nmol/LIso后 1μmol/LACh对Fc有间接的抑制作用 ,快速冲洗ACh后亦引起Fc的反跳性增强 ,与Iso组相比增强了 2 7.1%±13.2 % (n =7,P <0 .0 1)。 1μmol/LACh对心室肌细胞基础峰电流无明显影响 (n =8,P >0 .0 5 ) ;而以基础ICa L峰值(931± 16 1pA)作对照 ,在加入 10nmol/LIso后 ,ICa L峰电流增强到 1889± 331pA(n =7,P <0 .0 1) ;再给予 10nmol/LIso +1μmol/LACh快速灌流 2min ,峰电流降低为 15 12± 2 0 2pA(P <0 .0 1) ,用含 10nmol/LIso的细胞外液快速洗脱ACh ,峰电流增强到 2 10 7± 2 0 5pA ,较Iso组反跳性增强了 15 .8%± 4 .0 % (n =7,P <0 .0 1)。结论 :ACh对豚鼠心室肌收缩     

缺血再灌注时心肌细胞凋亡情况及去甲肾上腺素预处理对其影响

目的　探讨微量去甲肾上腺素预处理对大鼠缺血再灌注心肌细胞凋亡的影响。方法　大鼠在体缺血再灌注 (I/ R)模型 ,分别以缺血前去甲肾上腺素预处理 (NE- P) ,缺血预处理 (IP) ;采用末端脱氧核苷酸转换酶介导的生物素平移缺口末端标记技术 (TUNEL )检测各组心肌细胞凋亡情况及心肌梗死范围。结果　 I/ R组细胞凋亡率 (43.33%± 4.92 % )较高 ,NE- P组及 IP组虽然也有一定的心肌细胞凋亡率 :2 5.2 4 %± 1 .56% ,2 4 .44%± 2 .96% ,但较 I/ R组明显降低 (P<0 .0 0 1 )。 IP组及 NE- P组心肌梗死范围较 I/ R组明显减少 ,IP组及 NE- P组两项指标无显著差异。结论　心肌缺血再灌注损伤可诱发心肌细胞凋亡 ,NE- P能明显减少缺血再灌注诱导的心肌细胞凋亡的发生率 ,能明显减少心肌梗死范围 ,减轻缺血再灌注损伤 ;NE- P减少心肌梗死范围、减轻缺血再灌注损伤的机制可能与其能明显减少心肌细胞凋亡有关。     

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.