缺血后处理对肝脏缺血再灌注中肝窦内皮细胞损伤的保护作用

目的　探讨缺血后处理对肝脏缺血再灌注中肝窦内皮细胞损伤的保护作用。方法　建立大鼠局部肝脏缺血再灌注模型 ,将 2 4只健康雄性Wistar大鼠随机分为假手术、缺血再灌注、缺血后处理 3组 ,以缺血再灌前、反复多次的短暂预再灌、停灌作后处理 ,观察各组血浆肝酶及透明质酸 (HA)水平变化和肝组织中丙二醛 (MDA)、超氧化物歧化酶(SOD)、内皮素 1(ET 1)含量 ,并行肝组织病理形态学检查。结果　与缺血再灌注组相比 ,缺血后处理组肝酶的漏出、血浆HA水平及肝组织中MDA、ET 1的含量明显降低 (P <0 .0 1) ,而SOD活性则显著升高 (P <0 .0 1) ,肝组织病理学损伤亦明显减轻。结论　缺血后处理可通过抑制再灌注后氧自由基的过量生成而保护肝窦内皮细胞 ,减轻肝脏缺血再灌注损伤。     

糖尿病大鼠脑缺血再灌注后血管内皮生长因子及碱性成纤维细胞生长因子的表达

目的 研究糖尿病大鼠脑缺血再灌注后血管内皮生长因子(VEGF)、碱性成纤维细胞生长因子(bFGF)表达的情况.方法 采用STZ诱导产生慢性糖尿病大鼠模型,用线栓法制作大鼠脑缺血再灌注模型,对大鼠进行脑梗死体积计算并且采用免疫组化方法观察大鼠脑缺血再灌注不同时程(6,12,24,48 h)VEGF、bFGF的表达情况.结果 糖尿病组梗死体积明显大于正常血糖组;大鼠脑缺血再灌注6h,缺血侧脑组织梗死灶周边VEGF、bFGF免疫阳性反应已出现,12 h明显增多,24 h达高峰;糖尿病组在各时间点VEGF、bFGF表达比正常血糖组显著减少(P＜0.01).结论 脑缺血再灌注损伤后VEGF、bFGF表达增强,提示VEGF、bFGF对缺血性脑损伤有保护作用,可能与神经细胞和内皮细胞的自身保护作用有关.糖尿病加重了大鼠脑缺血再灌注损伤,造成VEGF、bFGF的表达不足.     

缺血后处理对大鼠肝移植术后血清TNFα和NE水平的影响

目的观察缺血后处理对大鼠移植肝缺血再灌注损伤的保护作用并探讨其可能机制。方法建立SD大鼠原位肝移植模型,48只健康雄性SD大鼠随机分为再灌注损伤组和后处理组。再灌注损伤组供肝植入前后无特殊处理,后处理组供肝植入后门静脉完全再通前给予多次短暂复灌复停作为后处理。两组受体一半（n=6）于再灌注后2h处死,检测血清肝功能指标、肿瘤坏死因子α（TNFα）和中性粒细胞弹性蛋白酶（NE）水平以及肝组织超氧化物歧化酶（SOD）和丙二醛（MDA）含量的变化;另一半（n=6）于再灌注后6h处死,留取肝组织制备HE染色切片,光镜下观察组织学变化。结果后处理组血清肝功能指标、炎性细胞因子水平及肝组织过氧化物含量均显著低于再灌注损伤组,而肝组织抗氧化酶活力显著高于再灌注损伤组,肝组织的病理改变也明显轻于再灌注损伤组。结论缺血后处理通过有控制地复氧,减少氧自由基的产生,抑制效应器TNFα、NE的合成及释放,发挥对大鼠移植肝缺血再灌注损伤的保护作用。     

眼针对脑缺血再灌注损伤大鼠血清ICAM含量的影响

目的观察眼针对脑缺血再灌注损伤大鼠血清细胞间黏附因子(ICAM)含量的影响,探讨眼针对脑缺血再灌注损伤治疗的作用机制。方法应用线栓法复制脑缺血再灌注大鼠模型,采用眼针治疗,于再灌注后3 h2、4 h、72 h进行神经功能缺损评分,采用ELISA方法测定大鼠血清ICAM含量的变化。结果与模型组比较,眼针组大鼠神经功能缺损程度评分明显下降,大鼠血清ICAM含量比模型组降低(P<0.01)。结论眼针具有明显改善大鼠脑缺血再灌注损伤的作用,其机制与降低机体血清ICAM含量有关。     

参附注射液对大鼠肝缺血再灌注NF-κB和PGI2/TXA2的影响

目的:探讨参附注射液对大鼠肝缺血再灌注损伤的保护作用及其机制.方法:24只Wistar大鼠随机分为IR组和SF组.SF组腹腔注射参附注射液,10 mL/kg.IR组大鼠给予相同剂量的生理盐水.两组均采用Pringle's法阻断肝门缺血15 min再灌注1h、3 h,测定血浆血栓素B2(thromboxane B2,TXB2)、6-酮-前列腺素F1α(6-keto-PGF1α)、肝组织NF-κB p65表达和肝组织匀浆GSH含量,及观察肝组织形态学改变.结果:再灌注3 h SF组血浆TXB2低于IR组(118.7±19.1 vs 386.3±282.7,P＞0.05),6-keto-PGF1α高于IR组(1081.7±282.7 vs 960.0±209.9,P＞0.05),二者比值TXB2/6-keto-PGF1α低于IR组(0.11±0.03 vs 0.39±0.24,P＜0.05);再灌注1 h SF组NF-κB p65表达低于IR组(59.33%±11.06% vs 75.83%±11.46%,P＜0.05);而GSH稍高于IR组(47.59±19.07 vs 37.32±4.71,P＞0.05).SF组肝实质细胞和线粒体损伤明显减轻.结论:参附注射液对肝缺血再灌注损伤有保护作用,其机制与降低TXA2/PGI2比值,抑制NF-κB活化有关.     

参附注射液对大鼠肝缺血再灌注NF-kappaB和PGI2/TXA2的影响

目的: 探讨参附注射液对大鼠肝缺血再灌注损伤的保护作用及其机制. 方法: 24只Wistar大鼠随机分为IR组和SF组. SF组腹腔注射参附注射液, 10 mL/kg. IR组大鼠给予相同剂量的生理盐水. 两组均采用Pringle's法阻断肝门缺血15 min再灌注1 h、3 h, 测定血浆血栓素B2(thromboxane B2, TXB2)、6-酮-前列腺素F1alpha(6-keto-PGF1alpha)、肝组织NF-kappaB p65表达和肝组织匀浆GSH含量, 及观察肝组织形态学改变. 结果: 再灌注3 h SF组血浆TXB2低于IR组(118.7±19.1 vs 386.3±282.7, P>0.05), 6-keto-PGF1alpha高于IR组(1081.7±282.7 vs 960.0±209.9, P>0.05), 二者比值TXB2/6-keto-PGF1alpha低于IR组(0.11±0.03 vs 0.39±0.24, P<0.05); 再灌注1 h SF组NF-kappaB p65表达低于IR组(59.33%±11.06% vs 75.83%±11.46%, P<0.05); 而GSH稍高于IR组(47.59±19.07 vs 37.32±4.71, P>0.05). SF组肝实质细胞和线粒体损伤明显减轻. 结论: 参附注射液对肝缺血再灌注损伤有保护作用, 其机制与降低TXA2/PGI2比值, 抑制NF-kappaB活化有关.     

原花青素对脑缺血再灌注损伤大鼠血脑屏障通透性和自由基含量的影响

目的 探讨原花青素(procyanidin,PC)对缺血再灌注损伤大鼠脑组织含水量、血脑屏障通透性和自由基含量的影响.方法 将大鼠随机分为假手术组、缺血再灌注组、PC低剂量治疗组和PC高剂量治疗组,线栓法建立局灶性脑缺血再灌注模型.观察缺血90 min再灌注24 h大鼠脑含水量和伊文斯蓝(EB)含量变化及超氧化物歧化酶(SOD)、丙二醛(MDA)含量变化,并进行2,3,5-三苯基氯化四氮唑(TTC)染色.结果 与假手术组比较,缺血再灌注组脑含水量和EB含量明显升高;与缺血再灌注组比较,PC高、低剂量治疗组脑含水量和EB含量明显降低(P<0.05),高、低剂量组之间差异亦具有统计学意义(P<0.05).与缺血再灌注组比较,PC治疗组显著降低MDA含量,增加SOD活性,高、低剂量组之间差异亦有统计学意义(P<0.05).PC高、低剂量治疗组脑梗死体积较缺血再灌注组减小,高、低剂量组之间差异具有统计学意义(P<0.05).结论 PC对缺血再灌注脑损伤具有保护作用,可能与减轻再灌注损伤后血脑屏障通透性和氧化性损伤有关.     

高压氧预处理对大鼠肠缺血再灌注机械屏障损伤的影响

目的：探讨高压氧预处理对肠缺血再灌注机械屏障损伤的影响及其机制。方法按随机数字表法将30只大鼠分为假手术组、缺血再灌注组和高压氧预处理组各10只。采用肠系膜上动脉无创性暂时阻断45 min、恢复肠系膜血流再灌注1 h的方法构建大鼠肠缺血再灌注损伤模型。最后进行血清TNF－α、肠组织髓过氧化物酶测定、肠道通透性和组织学的观察。结果假手术组、缺血再灌注组和高压氧预处理组空肠推进长度、空肠推进率、血清TNF－α水平、肠组织髓过氧化物酶活性差异均有统计学意义（ P均＜0．01）。缺血再灌注组黏膜下水肿、淤血,大量炎性细胞浸润,肠绒毛破坏,上皮细胞坏死,紧密连接、中间连接部分融合、模糊不清或消失;高压氧预处理组黏膜下血管轻微充血,少量炎性细胞浸润,微绒毛基本正常,可见清晰的紧密连接、中间连接和桥粒。结论缺血再灌注后大鼠肠道机械屏障出现不同程度的破坏,高压氧预处理可以通过其抗炎作用从而减轻大鼠肠机械屏障的缺血再灌注损伤。     

组胺对失血大鼠模型肠黏膜屏障的保护作用

目的 观察组胺(histamine)对失血大鼠肠黏膜屏障的保护作用.方法 将大鼠随机分为对照组、失血组和失血加组胺治疗组.除对照组外,其他各组大鼠均采取颈静脉放血制成失血模型.失血加组胺治疗组大鼠在放血后立即给予小肠内100、500和1000 ng/ml浓度组胺灌注.对照组和失血组用同样方法向小肠内灌注等量生理盐水.4h后在无菌条件下分别取出肝、肠系膜淋巴结和肾制成匀浆进行细菌培养.取部分回肠进行病理学检查.结果 对照组1只大鼠肝、肠系膜淋巴结有细菌生长,平均组织含菌量分别为0.32×105、0.26×105cfu/g,肾无菌生长;失血组7只大鼠肝、肠系膜淋巴结有细菌生长,5只大鼠肾有细菌生长,平均组织含菌量为9.92×105、8.14×105、3.25 x105cfu/g;失血加组胺治疗组共有4只大鼠肝、肠系膜淋巴结有细菌生长,3只大鼠肾有细菌生长,平均组织含菌量分别为(0.38～0.96)×105、(0.28～0.75)×105cfu/g和(0.20～0:26)×105cfu/g.失血加组胺治疗各组大鼠肝、肠系膜淋巴结和肾平均组织含菌量均明显低于失血组大鼠,差异有统计学意义(P＜0.01);组胺治疗各组之间肝、肠系膜淋巴结和肾平均组织含菌量差异无统计学意义(P＞0.05).病理学检查失血组大鼠肠黏膜损伤程度明显重于失血加组胺治疗各组.结论 在肠道缺血时,给予小剂量组胺肠内灌注,有减轻肠黏膜损伤、保护肠黏膜屏障、阻止肠道细菌移位的作用.     

疏血通对局灶性脑缺血大鼠神经保护和p53表达的影响

目的 探讨疏血通对大鼠脑缺血再灌注后可能的神经保护作用机制.方法 制备脑缺血再灌注模型,用疏血通进行干预,观察脑组织细胞的形态学改变,p53蛋白表达,细胞原位凋亡情况,脑梗死体积的变化.结果 大鼠脑缺血2 h再灌注24 h,治疗组的脑梗死体积较缺血组明显缩小(P<0.01).治疗组大鼠的神经功能缺损评分,在6 h时间点与缺血组比较无统计学意义,其余时间点均明显低于缺血组(P<0.05或P<0.01).缺血组和治疗组缺血再灌注6 h均可见凋亡细胞,表达高峰分别为48 h、72 h,治疗组的表达高峰时间延迟,且数量明显减少(P<0.05).p53蛋白在缺血再灌注后6 h出现表达,缺血组的表达高峰为48 h,治疗组的表达高峰为72 h,治疗组各时间点p53阳性细胞教较缺血组明显减少(P<0.05或P<0.01).结论 疏血通可减轻大鼠脑缺血再灌注损伤,缩小梗死体积,抑制p53蛋白的表达,改善神经功能.     

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.