瓜蒌皮提取物对人脐带静脉内皮细胞损伤的保护作用

目的研究瓜蒌皮提取物（EPT）对氧化低密度脂蛋白（OX-LDL）诱导的人脐带静脉内皮细胞（HUVECs）损伤的保护作用。方法在培养的人脐带静脉内皮细胞中加入OX-LDL（100mg／L）诱导内皮细胞损伤。检测细胞培养液中非对称性二甲基精氨酸（ADMA）、丙二醛（MDA）、乳酸脱氢酶（LDH）、一氧化氮（NO）、二甲基精氨酸二甲胺水解酶（DDAH）和肿瘤坏死因子-α（TNF-α）的含量。结果体外给予OX-LDL（100mg／L）显著诱导内皮细胞损伤,提高培养液中ADMA、MDA、LDH、和TNF-α水平,降低NO和DDAH水平。两种洗脱（水和70％乙醇洗脱）瓜蒌皮提取物均能显著抑制OX—LDL所致的ADMA、MDA、LDH和TNF-α浓度升高和NO、DDAH降低。结论瓜蒌皮提取物对OX—LDL诱导的人脐带静脉血管内皮细胞损伤有保护作用,其保护作用与降低ADMA和TNF-α浓度有关。     

盐酸小檗碱对高糖、高脂联合诱导内皮细胞分泌TNF-α的干预作用

目的 观察盐酸小檗碱(黄连素)对高糖、高脂联合诱导下血管内皮细胞分泌肿瘤坏死因子(TNF-α)的干预作用及对内皮细胞的保护作用.方法 体外培养人脐静脉内皮细胞,建立Glu+ ox-LDL损伤HUVECs模型.实验分组:对照组:DMEM培养液+l0％胎牛血清;模型组:Glu40 mmol/L+ ox-LDL 100 mg/L;黄连素低组:Glu 40 mmol/L+ox-LDL 100 mg/L+黄连素1.25 μg/ml;黄连素中组:Glu 40 mmol/L+ ox-LDL 100 mg/L+黄连素2.5 μg/ml;黄连素高组:Glu 40 mmol/L+ ox-LDL 100 mg/L+黄连素5μg/ml.检测细胞培养液中的内皮素(ET-1)、一氧化氮(NO)和TNF-α水平.结果 细胞增殖率:Glu 40 mmol/L+ ox-LDL 100 mg/L(模型组)培养HUVECs 24 h,与对照组比较细胞存活率降低(P＜0.01),说明造模成功,同时应用1.25 ～5.0 μg/ml黄连素治疗,细胞存活率明显提高(P＜0.01).NO:模型组NO水平显著低于对照组(P＜0.01),黄连素处理组NO水平显著高于模型组,以5μg/ml剂量组作用最显著(P＜0.01).ET-1:模型组ET-1比对照组显著增高(P＜0.01),黄连素各治疗组比模型组明显降低(P＜0.01).TNF-α:对照组与模型组间内皮细胞培养液中TNF-α水平差别有统计学意义(P＜0.01),黄连素各治疗组比模型组内皮细胞培养液中TNF-α水平明显降低(P＜0.01),但仍高于对照组(P＜0.01).结论 黄连素通过调节内皮NO/ET-1平衡、抗炎作用,改善Glu、ox-LDL联合诱导的内皮细胞损伤.     

低浓度乙醇对大鼠血管内皮损伤的保护作用

目的研究低浓度乙醇对低密度脂蛋白(LDL)诱导的血管内皮损伤的保护作用与内源性一氧化氮合酶抑制物的关系。方法SD大鼠在乙醚麻醉下,舌下静脉注射人血清LDL(4mg/kg)诱发血管内皮功能损伤。检测血中非对称性二甲基精氨酸(ADMA)、丙二醛(MDA)和一氧化氮(NO)的含量,并观察离体胸主动脉环的内皮依赖性舒张反应。结果单次静注LDL(4mg/kg)显著抑制乙酰胆碱(ACh)诱导的内皮依赖性舒张,增加血液中ADMA和MDA,降低NO水平。低浓度乙醇(10%,4ml/kg)能显著减轻LDL所致ACh诱导内皮依赖性舒张的损伤,能显著抑制ADMA和MDA浓度升高,降低NO浓度。但其他浓度乙醇(5%、15%,4ml/kg)对ADMA和NO浓度有较小的影响。结论低浓度乙醇对LDL诱导的血管内皮细胞损伤有保护作用,其保护作用与降低ADMA浓度有关。     

p38MAPK在ox-LDL诱导的血管内皮细胞损伤中的作用研究

目的探讨p38丝裂原活化蛋白激酶(p38MAPK)在氧化低密度脂蛋白(ox-LDL)诱导的血管内皮细胞损伤中的作用。方法人脐带静脉血管内皮细胞HUVEC-12分为对照组、ox-LDL组、实验1组、实验2组、实验3组。ox-LDL组、实验1组、实验2组、实验3组细胞分别用ox-LDL诱导处理,实验1组、实验2组、实验3组用不同浓度(5μmol/L、15μmol/L、30μmol/L)的p38MAPK抑制剂预处理。Western blot测定各组细胞中p38MAPK磷酸化水平,二硝基苯肼法、硫代巴比妥酸法、黄嘌呤氧化法分别测定培养液上清中乳酸脱氢酶(LDH)、丙二醛(MDA)和匀浆液中超氧化物歧化酶(SOD)含量,流式细胞术测定各组细胞凋亡情况,Western blot法测定各组细胞中Cleaved Caspase-3蛋白水平,比色法测定培养液中一氧化氮(NO)含量,ELISA法测定培养液中细胞间黏附分子-1(ICAM-1)、白细胞介素-1β(IL-1β)含量。结果 ox-LDL组细胞中p38MAPK磷酸化水平明显高于对照组(P0.05)。实验1组、实验2组、实验3组细胞中p38MAPK磷酸化水平明显低于ox-LDL组(P0.05)。ox-LDL组培养液中LDH、MDA含量明显升高,匀浆液中SOD水平明显降低,Caspase-3介导的细胞凋亡明显增多,培养液中NO含量明显降低,同时培养液中ICAM-1、IL-1β含量明显升高,与对照组相比,差异均具有统计学意义(P0.05)。实验1组、实验2组、实验3组细胞培养液中LDH、MDA含量明显降低,匀浆液中SOD水平明显升高,Caspase-3介导的细胞凋亡明显减少,培养液中NO含量明显升高,同时培养液中ICAM-1、IL-1β含量明显降低,与ox-LDL组相比,差异均具有统计学意义(P0.05)。结论 ox-LDL诱导血管内皮细胞p38MAPK磷酸化,而抑制p38MAPK后可以减少ox-LDL诱导的血管内皮细胞氧化损伤,减少细胞凋亡。     

非对称二甲基精氨酸在氧化低密度脂蛋白诱导基质金属蛋白酶2蛋白表达中的作用及机制

目的初步探讨非对称二甲基精氨酸(ADMA)在氧化低密度脂蛋白(ox-LDL)诱导基质金属蛋白酶2(MMP-2)蛋白表达中的作用及可能机制。方法观察ox-LDL对内皮细胞的损伤作用和MMPs抑制剂多西环素对ox-LDL诱导的内皮细胞MMP-2蛋白表达及ADMA水平的影响;观察ADMA对内皮细胞MMP-2蛋白表达及内皮细胞活性氧(ROS)水平的影响。结果(1)ox-LDL降低内皮细胞生存率呈浓度和时间依赖性;(2)多西环素能明显抑制ox-L,DL诱导的细胞生存率的降低,并显著降低ox-LDL(50 mg/L)诱导的ADMA水平与MMP-2蛋白表达的升高(多西环素5μg/ml时P<0.05,多西环素10,20μg/ml时P<0.01);(3)ADMA降低内皮细胞生存率呈浓度依赖性(P<0.01),并可升高内皮细胞ROS与MMP-2蛋白表达水平(ADMA 3μmol/L时P<0.05,ADMA 10,30μmol/L时P<0.01)。L精氨酸和细胞内抗氧化剂(PDTC)均能拮抗上述作用(P<0.01)。、结论ox-LDL诱导内皮细胞MMP-2蛋白表达水平升高可能涉及ADMA途径;多西环素对MMP-2蛋白表达的抑制作用可能与降低ADMA水平有关;ADMA可能通过诱导氧化应激增加MMP-2蛋白表达。     

黄连素对人脐静脉内皮细胞分泌一氧化氮的影响

目的 探讨黄连素对高糖、高脂损伤人脐静脉内皮细胞(HUVECs)分泌一氧化氮的影响及其保护内皮细胞的作用机制.方法 体外培养HUVECs,采用MTT法检测细胞生长存活率,并建立Glu+ ox-LDL损伤HUVECs模型.实验分组如下:正常组:DMEM培养液+10％胎牛血清;模型组:Glu 40 mmol/L+ ox-LDL 100 mg/L;黄连素低组:Glu 40 mmol/L+ ox-LDL 100 mg/L+黄连素1.25 μg/ml;黄连素中组:Glu 40 mmol/L+ ox-LDL 100 mg/L+黄连素2.5μg/ml;黄连素高组:Glu 40 mmol/L+ ox-LDL 100 mg/L+黄连素5μg/ml.采用硝酸还原酶法检测培养HUVECs上清液中NO含量,比较各组细胞NO的分泌水平.结果 模型组NO水平显著低于正常对照组(P＜0.01),黄连素处理组NO水平显著高于模型组,以5 μg/ml剂量组作用最显著(P＜0.01).结论 高糖、高脂处理HUVECs,可以降低HUVECs存活率,减少NO释放;黄连素可以提高Glu、ox-LDL联合诱导的HUVECs损伤的活性,并提高增殖率;黄连素改善Glu、ox-LDL联合诱导的HUVECs损伤的作用机制与其促进NO释放有关.     

黄花倒水莲皂苷C抑制单核-内皮细胞黏附作用及其机制研究

目的研究黄花倒水莲皂苷C(RC)对氧化型低密度脂蛋白(ox-LDL)诱导的单核-内皮细胞黏附的抑制作用及其机制。方法应用HPLC和ELISA法分别测定人单核细胞培养液中的非对称二甲基精氨酸(ADMA)和肿瘤坏死因子-α(TNF-α)水平;检测单核内皮细胞黏附率。结果ox-LDL(100mg/L)孵育24 h能显著增加单核-内皮细胞的黏附率以及细胞上清夜中ADMA [(1．91±0．10)μmol/L]和TNF-α[(130．23±3．55)ng/L]的水平;预处理RC(1、3、10μmol/L)4 h能抑制ox-LDL诱导的单核-内皮细胞黏附率增加[(226±18)、(203±13)、(186±15)个/高倍视野]及ADMA[(0．69±0．06)、(0．65±0．01)、(0．55±0．07)μmol/L]和TNF-α[(150．02±6．06)、(87．08±8．12)、(80．24±3．65)ng/L]释放增加,且呈浓度依赖性。结论RC对ox-LDL诱导的单核-内皮细胞黏附有抑制作用,其作用与降低ADMA和TNF-α水平有关。     

17β-雌二醇对ox-LDL诱导内皮细胞一氧化氮生成的影响

目的 观察17β-雌二醇和氧化低密度脂蛋白(ox-LDL)对人脐静脉内皮细胞一氧化氮(NO)的影响。方法用一氧化氮试剂盒测定不同浓度ox-LDL(50-200μg/L)和17β-雌二醇(0.1nmol/L-10nmol/L)作用于内皮细胞NO产量。结果ox-LDL对培养内皮细胞NO产生有明显抑制作用(P<0.01),雌激素(E2)可促进培养内皮细胞NO的生成(P<0.01),明显减弱ox-LDL对内皮细胞产生NO的抑制作用,与ox-LDL组相比,E2(0.5nmol/L)+ox-LDL组内皮细胞NO含量增加(P<0.01)。结论ox-LDL明显抑制内皮细胞NO的合成,雌激素则有明显的保护作用。     

二陈汤合桃红四物汤含药血清对ox-LDL诱导内皮细胞损伤的保护作用及机制

目的观察二陈汤合桃红四物汤含药血清对氧化型低密度脂蛋白(ox-LDL)诱导内皮细胞损伤的保护作用并探讨其可能的机制。方法培养EA.hy926细胞,随机分为对照组、ox-LDL组、干预组、抑制剂组。流式细胞仪检测各组细胞凋亡水平,比色法检测细胞内丙二醛(MDA)、一氧化氮(NO)水平及超氧化物歧化酶(SOD)活性,ELISA检测细胞上清液中肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)水平,Western blot检测磷脂酰肌醇3-激酶(PI3K)、磷酸化AKT(p-AKT)、内皮型一氧化氮合酶(eNOS)蛋白表达水平。结果与对照组比较,ox-LDL组细胞上清液中TNF-α和IL-6水平显著升高(P0.01),细胞内MDA含量显著升高(P0.01),SOD活性明显降低(P0.05),上清液中NO水平显著降低(P0.01),活性氧(ROS)含量和细胞凋亡率明显升高,PI3K、eNOS蛋白表达水平和AKT蛋白磷酸化水平显著降低(P0.01)。与ox-LDL组比较,干预组细胞上清液中TNF-α和IL-6水平显著降低(P0.01),细胞内MDA含量显著降低(P0.01),SOD活性明显升高(P0.05),上清液中NO水平显著升高(P0.01),ROS含量和细胞凋亡率明显降低,PI3K、eNOS蛋白表达水平和AKT蛋白磷酸化水平显著升高(P 0.01)。与干预组比较,抑制剂组细胞上清液中TNF-α和IL-6水平显著升高(P0.01),细胞内MDA含量显著升高(P0.01)、SOD活性明显降低(P0.05),上清液中NO水平明显降低(P0.05),细胞内ROS含量升高,PI3K、eNOS蛋白表达水平和AKT蛋白磷酸化水平显著降低(P0.01)。结论二陈汤合桃红四物汤含药血清能有效保护ox-LDL诱导的内皮细胞损伤,其机制可能与激活PI3K/AKT/eNOS信号通路有关。     

沙格列汀对过氧化氢诱导损伤的血管内皮细胞二甲基精氨酸二甲胺水解酶/非对称性二甲基精氨酸/内源性一氧化氮合酶通路影响的研究

目的观察二肽基肽酶-4(DPP-4)抑制剂沙格列汀对过氧化氢(H2O2)诱导损伤的血管内皮细胞二甲基精氨酸二甲胺水解酶/非对称性二甲基精氨酸/内源性一氧化氮合酶(DDAH/ADMA/eNOS)通路的影响。方法以培养人脐静脉内皮细胞株(HUVEC)作为靶细胞,在内皮细胞培养基中加入100μmol/L的H2O2制备细胞损伤模型,以20μmol/L沙格列汀进行干预,观察24~72h,检测细胞上清一氧化氮(NO)含量、ADMA浓度,检测细胞中NOS活性、DDAH活性及DDAH蛋白表达量。结果H2O2作用HUVEC后,细胞上清中NO含量降低,而ADMA浓度增加(P0.05)。细胞中NOS活性、DDAH活性、DDAH-Ⅱ蛋白表达量降低(P0.05);而加入沙格列汀,细胞上清中NO含量升高,ADMA浓度降低(P0.05)。细胞中NOS活性、DDAH活性、DDAH-Ⅱ蛋白表达量升高(P0.05)。结论沙格列汀通过对DDAH/ADMA/eNOS通路的调节作用改善H2O2诱导的内皮细胞NO生成减少。     

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.