Roscovitine抑制大鼠颈总动脉球囊损伤后内膜增生的研究

目的:观察roscovitine对球囊损伤后大鼠颈总动脉血管平滑肌细胞及内膜增生的抑制作用,以期提供新型的支架涂层药物。方法:建立大鼠颈总动脉球囊损伤模型模拟经皮冠状动脉腔内介入术(PCI)术后再狭窄,干预组损伤局部给予roscovitine(200μmol/L)孵育10分钟。14天后取材,免疫荧光染色观察roscovitine对局部血管平滑肌细胞增殖的作用;HE染色观察roscovitine对内膜增生的作用。结果:本研究建立了大鼠颈总动脉球囊损伤模型,球囊损伤后14天,局部血管平滑肌细胞增殖活跃、内膜增生明显。Roscovitine干预后,血管平滑肌细胞增殖率明显降低,内膜增生被显著抑制,管腔狭窄率和内膜中膜面积比值显著降低。结论:Roscovitine显著抑制大鼠颈总动脉球囊损伤后局部血管平滑肌细胞增殖,进而有效抑制内膜增生,降低再狭窄发生率。     

32P液体球囊血管内照射预防血管介入治疗后再狭窄的实验研究

目的观察血管内液体球囊放射治疗对血管介入治疗后再狭窄的影响，为其临床应用提供实验依据；同时通过放射治疗效应来探讨放射治疗防止再狭窄发生的可能机制。方法兔髂动脉经球囊过度扩张损伤后，一侧经３２Ｐ液体球囊血管内照射作治疗，另一侧未经治疗作对照。用计算机图像分析方法观察血管组织形态学的变化；免疫组化方法测定增殖细胞核抗原（ＰＣＮＡ）阳性细胞以了解血管内膜增殖过程。结果兔髂动脉经球囊过度扩张损伤后，血管内膜可明显增生，ＰＣＮＡ染色为强阳性；经３２Ｐ液体球囊照射后的对侧损伤髂动脉，内膜增生明显受抑，ＰＣＮＡ染色为弱阳性，外弹力板围绕面积均增加，管腔面积无明显变化。结论３２Ｐ液体球囊确可防止再狭窄的形成，其机制可能是通过抑制平滑肌细胞增殖和改善血管重塑形成。     

胰岛素样生长因子1受体抗体对大鼠血管平滑肌细胞增殖的影响

目的观察胰岛素样生长因子1受体抗体对大鼠血管平滑肌细胞增殖的影响。方法球囊导管损伤大鼠一侧颈总动脉,7天后体外培养受损血管的中膜平滑肌细胞,以损伤侧血管细胞为实验组,以对侧正常血管中膜平滑肌细胞为对照组;采用-αactin免疫细胞化学法进行细胞鉴定;在细胞的培养悬液中加入不同浓度的胰岛素样生长因子1受体抗体作用24 h,然后采用5-溴-2脱氧尿苷细胞增殖检测法检测细胞的增殖程度。结果大鼠颈总动脉球囊损伤后,体外培养的中膜平滑肌细胞表现出显著的增殖性(与对照组比较,P<0.01);胰岛素样生长因子1受体抗体可以显著抑制大鼠平滑肌细胞的增殖,呈现出浓度依赖性特征(组间比较,P<0.01)。结论胰岛素样生长因子1受体抗体具有抑制平滑肌细胞增殖的作用,有望用于治疗平滑肌细胞增殖性疾病。     

通过损伤动脉外膜建立兔颈动脉粥样硬化狭窄和再狭窄模型

目的 球囊扩张后动脉再狭窄严重制约着经皮血管腔内治疗术的治疗效果,为探讨动脉再狭窄的发病机制,本研究尝试建立动脉再狭窄模型.方法 采用右颈总动脉可吸收线套环缩窄术加高脂饲料喂养新西兰兔,建立颈动脉粥样硬化狭窄模型.4周后,自右颈外动脉远端结扎并切断颈外动脉,由结扎近心侧插入扩张球囊导管进行球囊扩张,建立动脉再狭窄模型.然后以普通饲料喂养4周后,对颈动脉标本进行组织学及形态学分析,并以对侧颈总动脉为正常对照组.结果 套环颈动脉管腔较对照组有缩窄,平滑肌细胞有增殖,排列紊乱,内皮细胞呈乳头状突入管腔.球囊扩张后,内膜较对照组及动脉缩窄组显著增厚(P<0.05).组织切片可见内、中弹力层断裂,内膜有大量泡沫细胞,脂质沉着,粥样斑块组织形成.外膜滋养血管数量增加.结论 通过本方法可成功构建实验兔血管再狭窄模型,且操作简单,建立模型时间短,为探讨血管再狭窄的发生机制提供了条件.     

A20基因转染对大鼠颈动脉再狭窄和核因子κB表达的影响

目的观察局部转染锌指蛋白A20基因对大鼠颈动脉再狭窄模型球囊损伤后内膜增生和血管平滑肌细胞增殖的影响并探讨其可能的机制。方法建立大鼠颈总动脉球囊损伤模型。104只健康雄性SD大鼠随机分为4组(n=26):假手术组、模型组、对照组和治疗组。假手术组只进行颈动脉结扎,不进行球囊损伤术;模型组只进行球囊损伤术,不进行局部转染治疗;对照组球囊损伤术后局部灌注Lipofectamine 2000 Reagent TE buffer;治疗组球囊损伤术后局部灌注Lipofectamine 2000 Reagent pCAGGS-GFP/A20重组质粒。荧光显微镜观察A20在损伤动脉壁的转染效率;病理组织学观察内膜增生情况;溴脱氧尿嘧啶核苷标记技术评估血管平滑肌细胞的增殖指数;分别用免疫组织化学染色、Western-blotting方法检测核因子κB p65在各组大鼠颈总动脉中的表达情况。结果大鼠颈总动脉球囊损伤术后14 d模型组和对照组血管内膜显著增生。A20基因转染可抑制新内膜面积的增加(减少47.8%,P<0.05)和内/中膜比值的增加(减少42.9%,P<0.05)。术后10 d治疗组血管平滑肌细胞体内增殖指数(9.6%±2.3%)显著少于对照组(26.7%±5.1%,P<0.05)。术后10 d治疗组血管壁细胞核因子κB p65阳性细胞率显著低于对照组(P<0.05)。术后7 d、14 d和28 d治疗组血管组织核因子κB p65的蛋白表达量显著低于对照组(P<0.05)。结论局部转染A20基因可抑制损伤血管内膜增生及平滑肌细胞的增殖,其分子机制可能通过其负反馈抑制了核因子κB介导的胞内信号转导途径。     

大黄素对血管平滑肌细胞增殖影响的实验研究

为研究大黄素对血管平滑肌细胞增殖的影响，用兔髂动脉中膜层进行体外血管平滑肌细胞（ＳＭＣ）培养及氚标记胸苷掺入技术，探讨了中药纯品——大黄素对兔髂动脉正常动脉组ＳＭＣ、动脉硬化并球囊损伤后培养的ＳＭＣ增殖情况。结果表明：大黄素可抑制ＳＭＣ增殖，其主要抑制细胞由Ｇ０期向Ｓ期转化，且抑制作用为剂量依赖性，对动脉硬化并球囊损伤组抑制作用大于对正常细胞作用。本实验为临床可能应用该药抑制ＳＭＣ增殖，预防动脉介入性治疗后再狭窄提供理论依据。     

局部应用前列腺素E1对兔颈动脉损伤后内膜增生的影响

目的观察局部应用医用胶携载前列腺素E1,对兔颈总动脉损伤后内膜增生的影响。方法将40只兔随机分成假手术组、对照组、前列腺素E1组、医用胶组,每组各10只,球囊导管法损伤右侧颈总动脉内膜,术后2周切取损伤血管,通过形态学观察和免疫组织化学检查,了解内膜增生和平滑肌细胞增殖情况。结果前列腺素E1组血管内膜面积、管腔狭窄率、增殖的平滑肌细胞数等指标均较对照组显著减少(P<0.01),而医用胶组无明显效果(P>0.05)。结论医用胶携载前列腺素E1局部用于血管外膜可有效抑制血管损伤后内膜的增生,对防治动脉手术后管腔再狭窄有潜在的应用价值。     

新型颈动脉再狭窄兔模型的建立

目的 :为了解再狭窄发生机制 ,进行再狭窄预防研究建立新西兰兔动物模型。方法 :采用直流电刺激的方法刺激兔颈总动脉外膜 ,在初步产生动脉纤维斑块的基础上 ,给予球囊扩张。结果 :通过血管造影及组织形态学观察 ,证实兔颈总动脉发生了动脉再狭窄病理改变。模型组血管腔内面积明显缩小 （P<0 .0 1） ,血管内膜增厚 （P<0 .0 1）。结论 :采用封闭群动物新西兰兔建立的颈总动脉狭窄模型具有模拟性好、死亡率低、实用性强和成功率高等优点     

DIM对兔血管损伤后平滑肌细胞C-myc表达的影响

目的探讨DIM对血管损伤后血管平滑肌细胞增殖的影响及其可能机制。方法制备兔血管再狭窄模型,21只兔随机分为假手术组、模型组和DIM组,观察各组颈总动脉形态学变化,采用免疫组织化学技术观察血管内膜C-myc的表达。结果假手术组动脉各层结构正常;模型组动脉内膜层出现泡沫细胞,平滑肌细胞增殖,血管内膜明显增厚,C-myc表达明显增加;DIM组血管平滑肌细胞增殖程度降低;与假手术组比较,模型组C-myc表达显著增强(P<0.05),而DIM明显降低C-myc的表达(P<0.01)。结论 DIM通过下调C-myc基因的表达而抑制血管内膜增生,有利于血管再狭窄的防治。     

蛋白酶体抑制剂MG132对球囊损伤后血管狭窄的影响

目的 观察蛋白酶体抑制剂MG132对球囊损伤后血管狭窄的影响.方法 将新西兰白兔40只随机分成正常对照组、高脂组、球囊损伤组和MG132组.球囊损伤组和MG132组兔采用球囊拉伤颈总动脉复制血管损伤后狭窄模型;MG132组在损伤血管局部应用蛋白酶体抑制剂MG132.喂养2周、4周和8周后取颈总动脉损伤段血管制成病理切片行HE染色,测定内膜厚度、中膜厚度和管腔面积,评价颈总动脉血管狭窄.结果 球囊损伤组颈总动脉发生明显狭窄、管腔减小、内膜增厚,有泡沫细胞和大量血管平滑肌细胞增殖,而MG132组的病变明显减轻.结论 用球囊拉伤新西兰白兔颈总动脉复制的血管狭窄模型,颈总动脉发生明显狭窄,局部应用蛋白酶体抑制剂MG132能够抑制血管内膜增生,抑制损伤后血管狭窄.     

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.