血管紧张素转化酶2在心肌缺血再灌注损伤中的意义

目的:研究心肌缺血再灌注损伤不同时期、不同脏器血管紧张素转化酶2(ACE2)蛋白表达水平.方法:建立在体心肌缺血再灌注模型,于再灌注前后不同时点取心肌组织、肾脏、睾丸及肝脏等组织,采用免疫组化方法检测组织ACE2的表达.用放射免疫法测定血浆及心肌组织中血管紧张素Ⅱ(AngⅡ)含量.结果:缺血再灌注1～12 h肾小管上皮细胞ACE2表达增多,缺血再灌注12 h后心脏ACE2开始表达增加.肝脏无论再灌注早期还是再灌注晚期几乎都不表达.缺血再灌注1～12 h血浆及心肌组织中AngⅡ含量增高.结论:心脏缺血再灌注后血浆及心肌AngⅡ表达增高, ACE2主要由肾脏器官分泌产生,心肌在再灌注晚期表达ACE2.     

ATP后适应对大鼠心肌缺血再灌注损伤的保护作用

目的观察三磷酸腺苷（ATP）后适应及ATP后适应不同给药方式对大鼠在体心肌缺血再灌注损伤（MI-RI）的影响。方法采用结扎大鼠左冠状动脉前降支30 min、再灌注120 min的方法复制大鼠心肌MIRI模型。实验动物随机分为假手术组、缺血再灌注组、ATP后适应组,ATP后适应＋再灌注早期给药组。实验终点测定心肌梗死面积,观察血清丙二醛（MDA）及总超氧化物歧化酶（T-SOD）含量变化,应用免疫组化法测定组织中NF-κB的表达,TUNEL法检测心肌细胞凋亡指数。结果与缺血再灌注组相比,ATP后适应组心肌梗死面积明显缩小,血清MDA含量降低,NF-κB表达降低,心肌细胞凋亡指数降低,血清T-SOD含量升高（P〈0.05或〈0.01）;ATP后适应组和ATP后适应＋再灌注早期给药组的各项指标无统计学差异（P〉0.05）。结论 ATP后适应对心肌MIRI有保护作用,其机制可能与抗氧自由基损伤、抑制缺血再灌注后NF-κB过度表达及减少心肌细胞凋亡有关。     

抗氧化剂和内质网钙释放阻滞剂对老年大鼠肾脏缺血/再灌注损伤中凋亡的影响

目的 探讨联合应用抗氧化剂BHA（Butylated Hydroxyanisole,叔丁基羟基茴香醚）和内质网钙释放阻滞剂TMB-8[8-（N,N-diethylamino）-noctyl-3,4,5-trimethoxybenzoate）]对老年大鼠肾脏缺血/再灌注（I/R）损伤时肾组织中细胞凋亡蛋白酶-3（caspase-3）表达及活性的影响.方法 27月龄Wistar大鼠分别随机分为假手术组、I/R模型组、I/R＋BHA＋TMB-8组,双侧肾动脉夹闭30 min/再灌注18 h制作模型.观察肾功能改变,原位末端标记（TUNEL）法检测肾小管上皮细胞凋亡情况,Northern blot检测肾组织中caspase-3 mRNA表达,比色法测定肾组织中caspase-3活性.结果 肾脏I/R损伤时,老年大鼠肾功能明显减退,大量肾小管上皮细胞凋亡,肾组织caspase-3 mRNA表达及活性增加;BHA＋TMB-8能显著改善老年大鼠肾功能,减轻肾小管上皮细胞凋亡,降低肾组织caspase-3表达及活性.结论 BHA＋TMB-8联合治疗能明显抑制老年大鼠肾脏I/R损伤时肾组织caspase-3表达及活性,从而减轻肾小管上皮细胞凋亡,保护肾功能.     

早期生长反应因子1过表达促进肾小管上皮细胞转分化

目的:探讨早期生长反应因子1(Egr-1)在肾小管上皮细胞转分化中的作用. 方法:(1)体外实验:用pcDNA 3.1,pcDNA 3.1/Egr-1转染肾小管上皮细胞株HK-2,qRT-PCR法、Westem免疫印迹法检测Egr-1及转分化标志物E-cadherin、成纤维细胞特异性蛋白(Fsp-1)mRNA及蛋白水平的表达变化;用pcDNA 3.1/Egr-1和siEgr-1或psilencer 3.1共转染HK-2,Western免疫印迹法检测Egr-1、E-cadherin、Fsp-1蛋白水平的表达变化.(2)体内实验:建立大鼠慢性肾纤维化模型--5/6肾脏次全切除,造模成功后免疫组化法检测大鼠肾组织中Egr-1、E-cadherin、Fap-1的表达. 结果:(1)与转染空载体相比,HK-2细胞过表达Egr-1后,上皮细胞标志性蛋白E-cad-herin表达减弱,成纤维细胞标志性蛋白Fsp-1表达增强(P<0.05),提示出现肾小管上皮细胞转分化表型.而用小干扰RNA干扰掉Egr-1后,与空载体组及亲本细胞组相比,转分化表型得到逆转.(2)体内实验证实,与假手术组(SOR)相比,5/6肾脏次全切除肾组织中,转分化标志蛋白E-cadherin表达减弱、Fsp-1表达增加,同时肾小管上皮细胞Egr-1的表达明显升高,提示肾小管上皮细胞发生转分化,且其与Egr-1过表达密切相关. 结论:Egr-1的过表达促进了肾小管上皮细胞转分化,参与肾间质纤维化的发生发展.     

线粒体连接蛋白43参与缺血后处理对兔急性心肌缺血再灌注损伤的保护作用

目的 探讨线粒体连接蛋白43(connexin43,Cx43)和线粒体ATP敏感性钾通道(mitoK_(ATP)~+)在缺血后处理保护兔心肌缺血再灌注损伤中的作用.方法 新西兰大白兔64只,建立心肌缺血再灌注模型,给予冠状动脉左前降支30 min缺血,240 min再灌注.随机分为4组,每组16只:假手术组、缺血再灌注组、缺血后处理组和5-羟葵酸加缺血后处理组.测定血浆磷酸肌酸激酶同工酶(CK-MB),肌钙蛋白I(cTnI)含量以及心肌梗死面积,采用电子显微镜观测心肌线粒体结构变化,Western blot检测线粒体Cx43蛋白表达.结果 缺血后处理组心肌梗死面积为(19.1±3.9)%,明显低于缺血再灌注组(35.7±5.8)%,P＜0.01.再灌注4 h末血浆CK-MB与cTnI活性,缺血后处理组明显低于缺血再灌注组和5-羟葵酸加缺血后处理组(P＜0.01).与假手术组比较,其他各组线粒体均损伤明显(P均＜0.01);缺血后处理组线粒体损伤程度轻于缺血再灌注组(P＜0.01);缺血后处理组线粒体损伤程度明显轻于5-羟葵酸加缺血后处理组(P＜0.01).缺血再灌注组和5-羟葵酸加缺血后处理组线粒体Cx43蛋白表达均显著低于假手术组(P均＜0.05);缺血后处理组心肌线粒体Cx43蛋白表达明显高于缺血再灌注组(P＜0.05);缺血后处理组心肌线粒体Cx43蛋白表达明显高于5-羟葵酸加缺血后处理组(P＜0.05).结论 线粒体Cx43可能参与了缺血后处理的心肌保护作用,其机制可能与mitoK_(ATP)~+有关.     

叔丁基羟基茴香醚对衰老大鼠肾脏缺血/再灌注损伤的保护作用

目的观察老年大鼠肾脏缺血／再灌注（I／R）模型中肾小管上皮细胞的损伤变化，探讨ROS清除剂对I／R损伤的保护作用。方法27月龄大鼠分别随机分为假手术组、I／R模型组、活性氧清除剂——叔丁基羟基茴香醚（BHA）干预组。夹闭双侧肾动脉30min再灌注18h制成I／R模型。观察肾功能、肾脏病理改变、肾小管上皮细胞凋亡情况，检测肾组织caspase-3，测定肾组织脂质过氧化物丙二醛（MDA）含量和超氧化物歧化酶（SOD）活性。结果（1）肾脏I／R损伤时，老年大鼠肾功能明显减退，肾组织病理改变比较明显，大量肾小管上皮细胞凋亡，肾组织caspase-3、肾组织中MDA含量增加、SOD活性下降（P〈0．05）。（2）BHA能明显的改善肾功能、组织病理改变和凋亡相关指标（P〈0、05）；BHA能减少组织中MDA含量，部分恢复组织中SOD含量。结论老年大鼠肾脏I／R损伤时肾小管上皮细胞凋亡增加，肾功能减退。ROS堆积后，线粒体损伤导致肾小管上皮细胞凋亡。清除ROS可以抑制肾小管上皮细胞凋亡，减轻I／R损伤。     

葛根素后处理对大鼠心肌缺血再灌注心肌细胞的影响

目的观察葛根素后处理对大鼠心肌缺血再灌注心肌细胞凋亡及Bcl-2和Bax蛋白的影响。方法 SD大鼠随机分为假手术组、缺血再灌注组、葛根素后处理组,每组8只。制备大鼠心肌缺血再灌注模型,假手术组只穿线,不结扎左冠状动脉;缺血再灌注组缺血45 min,后再灌注120 min;葛根素后处理组,结扎左冠状动脉45 min,后再灌注120 min。再灌注前3 min和再灌注后2min内静脉注入葛根素1.25 mg/kg。应用免疫组化SP法观察Bcl-2和Bax蛋白表达率,采用TUNEL法观察各组心肌细胞的凋亡率,并在光镜及电镜下观察细胞形态学变化。结果与心肌缺血再灌注组相比,假手术组和葛根素后处理组心肌凋亡细胞数较低(P0.05),Bax表达较低(P0.05),Bcl-2表达较高(P0.05)。结论葛根素后处理可以影响心肌细胞Bcl-2、Bax的表达,抑制心肌细胞的凋亡,对缺血再灌注损伤心肌细胞有保护作用。     

去甲斑蝥素抑制单侧输尿管梗阻大鼠肾小管上皮-间充质转分化的实验研究

目的:利用单侧输尿管梗阻(UUO)大鼠模型,观察去甲斑蝥素(norcantharidin,NCTD)对肾小管上皮细胞间质转分化的影响。方法:SD大鼠随机分为假手术组(Sham组)、模型组(UUO组)和UUO+NCTD治疗组(NCTD组),每组6只。采用单侧(左)输尿管结扎方法,建立梗阻性肾小管间质纤维化大鼠模型,Sham组只游离输尿管而不结扎。术后14d处死动物,取结扎侧肾脏,同时处死Sham组大鼠,取出肾组织。采用免疫组化、Western Blot及RT-PCR检测α平滑肌肌动蛋白(α-SMA)、E钙黏蛋白(E-cadherin)与转化生长因子β1(TGF-β1)蛋白的mRNA表达的变化。结果:免疫组化、Western Blot及RT-PCR均显示,与Sham组比较,UUO组肾组织α-SMA和TGF-β1的mRNA表达升高、E-cadherin蛋白和mRNA表达降低(P<0.05);NCTD能抑制UUO大鼠肾组织α-SMA和TGF-β1表达的上调,上调E-cadherin的表达(P<0.05)。结论:NCTD具有抑制UUO大鼠肾小管上皮-间充质转化的作用,该作用可能与抑制TGF-β1的过表达有关。     

黄体酮对大鼠局灶性脑缺血再灌注损伤后脑组织神经生长因子表达的影响

目的 观察黄体酮对大鼠局灶性脑缺血-再灌注损伤后缺血区皮层神经生长因子(NGF)和脑源性神经营养因子(BDNF)在mRNA与蛋白质水平表达的影响,探讨黄体酮在脑缺血-再灌注损伤中的脑保护作用机制. 方法 采用SD雄性大鼠局灶性脑缺血-再灌注损伤模型.将96只大鼠随机分为4组:假手术组、缺血再灌注组、溶剂组和黄体酮组各24只.应用Real time-PCR和Western blot技术分别对缺血区皮层NGF和BDNF mRNA与蛋白表达情况进行测定. 结果 在缺血区皮层,缺血2h再灌注6h后,缺血再灌注组NGF和BDNF的mRNA及蛋白质表达达高峰,再灌注24 h后,回复到假手术组水平;缺血2h再灌注12 h后,黄体酮组NGF和BDNF mRNA及蛋白表达达高峰,再灌注24 h后,表达仍高(P＜0.05). 结论 黄体酮可以使脑缺血-再灌注损伤后NGF和BDNF的mRNA表达上调,促进脑内NGF和BDNF蛋白的合成,从而发挥脑保护作用.     

脐血间充质干细胞治疗大鼠肾缺血再灌注损伤的效果及机制探讨

目的 观察脐带间充质干细胞(UC-MSCs)治疗大鼠肾脏缺血再灌注损伤(I/R)的效果,并探讨其机制.方法 60只大鼠,随机分为假手术组、I/R组、UC-MSCs组,各20只.UC-MSCs组大鼠切除右侧肾,夹闭左侧肾蒂1h,再灌注30 min后尾静脉注射人UC-MSCs 1×106个(0.5 mL).I/R组注射等量生理盐水.假手术组仅切除右肾,分离左肾肾蒂但不夹闭.术后24、48 h分别处死10只大鼠,取肾脏标本做组织形态学检查,采用免疫组化方法检测肾组织中的细胞间黏附分子( ICAM-1),计数肾组织中多型核白细胞(PMNL)的浸润数及eGFP阳性的UCMSCs数.结果 I/R组术后24h已可见明显近曲小管排列紊乱、疏松,上皮细胞肿胀,广泛空泡变性及片状坏死,可见上皮细胞脱落至管腔内.术后48 h更严重.假手术组肾小管排列整齐,间质无充血水肿.UC-MSCs组组织损伤较轻,肾小管排列基本正常,小管上皮细胞轻度浊肿,刷状缘脱落,可见管型.炎细胞浸润亦较I/R组明显减轻.术后24 h UC-MSCs组、I/R组、假手术组肾小管评分分别为(71.90±16.26)分、(169.60±15.68)分、(1.40±1.17)分,术后48h分别为(90.20±15.01)分、(182.40±12.77)分、(1.40±1.07)分.术后24 h UC-MSCs组、I/R组、假手术组肾组织白细胞计数分别为(18.90±7.45)个/mm2、(39.20±11.99)个/mm2、(0.90±1.10)个/mm2,术后48h分别为(27.20±9.53)个/mm2、(66.70±15.5)个/mm2、( 1.30±1.77)个/mm2.术后24 h UC-MSCs组、I/R组、假手术组肾组织ICAM-1相对表达量分别为2.224 9±0.963 7、5.2569±0.739 7、0.2170±0.1063,术后48 h分别为4.405 6±0.980 2、8.1012±1.6640、0.191 9±0.087 6.以上指标相同时点比较UC-MSCs组均明显低于I/R组,高于假手术组(P均＜0.05).术后24、48 h UC-MSCs组大鼠肾组织eGFP阳性细胞率分别为9.8％±1.2％、21.2％±7.3％,其余2组均未检出CFP阳性细胞.结论 UC-MSCs能够抑制大鼠肾缺血再灌注损伤,其机制与其抑制缺血再灌注损伤大鼠肾组织中ICAM-1表达上调和PMNL浸润有关.     

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.     

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.     

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.