L-Arg在心肺联合移植中对心肺保护作用的实验研究

目的 研究 L-Arg 在心肺联合移植中对心肺的保护作用及可能机制.方法 将健康成年犬 20 只随机分为两组,对照组以 4 ℃LPD液灌注及保存供肺,实验组以 4 ℃含 L-Arg (500 mg/kg)的LPD液灌注及保存供肺.心脏灌注液采用 4 ℃ St.thomas液,实验组中加入 L-Arg 300 mg/500 mL.分别监测受体麻醉后和心肺移植后主动脉开放5 min和主动脉开放30 min的血气分析,测定心肌和肺组织中一氧化氮(NO)、超氧化物歧化酶(SOD)、丙二醛(MDA)的含量及肺组织的湿/干重比(W/D),并观察移植肺组织的超微结构变化.结果实验组血氧分压(PaO2)高于对照组,二氧化碳分压(PaCO2)明显低于对照组.实验组心肌和肺组织中的 NO及SOD的含量较对照组增高(P＜0.01),而 MDA 的含量较对照组降低(P<0.05).实验组较对照组的 W/D 低(P<0.05).电镜检查实验组的肺组织损伤轻于对照组.结论 L-Arg 可增强保存液对心脏的保护作用,改善移植肺的肺功能,能减轻供肺损伤,增加心肺联合移植的成功率.     

前列腺素E1对犬心肺联合移植供肺的保护作用

目的研究前列腺素E1（PGE1）在犬心肺联合移植过程中对供肺的保护作用。方法建立犬心肺联合移植模型,先于供体肺动脉内注射PGE1,再在肺动脉内灌注含有PGE1的低温EC（Euro-Collins）溶液,恢复血流灌注后观察实验组及对照组在30、60、90、120 m in的平均肺动脉压（MPAP）、动脉血氧分压（PaO2）的变化,恢复血流灌注1h后,取移植肺组织为标本,检测肺组织中髓过氧化物酶（MPO）活力、肺湿干质量比,HE染色,光镜下观察病理变化。结果实验组中PaO2值在各时间段较对照组明显升高,MPAP值在各时间段较对照组明显降低。实验组肺组织中MPO活性显著低于对照组,实验组的肺湿干质量比较对照组显著降低。病理切片显示对照组的肺组织有较严重的白细胞浸润及肺水肿形成,而实验组的病变程度较对照组轻微。结论在心肺联合移植过程中应用前列腺素E1,可减轻移植肺缺血/再灌注损伤,保护移植肺的肺功能,增加心肺联合移植的成功率。     

脑缺血再灌注细胞外液兴奋性氨基酸与一氧化氮的变化及丹参的影响

目的　观察脑缺血再灌注细胞外液兴奋性氨基酸 (EAAs)与一氧化氮 (NO)的变化及丹参的影响。方法　采用沙土鼠全脑缺血再灌注模型 ,应用微透析技术及高压液相色谱测量方法 ,观察纹状体区细胞外液中EAAs及NO代谢产物变化。结果　在对照组 ,脑缺血 30min后 ,细胞外液中EAAs水平明显增加 ,随着再灌注时间延长EAAs水平逐渐接近正常 ,同时细胞外液中NO代谢产物也明显升高。L 精氨酸 (L Arg)组 ,EAAs及NO代谢产物水平均高于对照组 (P <0 .0 1) ;丹参组 ,EAAs及NO代谢产物水平均低于对照组 (P <0 .0 1) ,在丹参加L Arg组 ,EAAs及NO代谢产物水平与对照组差异无显著性意义。结论　脑缺血后 ,纹状体区细胞外液EAAs及NO代谢产物水平均明显增加 ,丹参不仅可降低EAAs及NO代谢产物水平 ,而且可逆转L Arg的损害作用     

蛇床子素注射液在犬原位心脏移植中对供心的保护作用

目的探讨蛇床子素注射液在犬原位心脏移植中对供心的保护作用。方法取健康杂种犬24条,随机分为对照组和试验组;建立犬原位心脏移植模型,先于试验开始前1h经供体犬股静脉内滴注蛇床子素注射液(25mg/kg),再用含有蛇床子素注射液(25mg/kg)的4℃改良ST.Thomas液对供体心脏进行灌注和保存,心脏移植成功后5min从右房采集血液标本,检测实验组及对照组血清超氧化物歧化酶(SOD)、丙二醛(MDA)含量及心肌肌钙蛋白(cTnI)、乳酸脱氢酶(LDH)、心肌肌酸激酶(CK)及其同工酶(CK-MB)漏出率;并于移植成功后10min取移植心脏左室心尖部心肌组织用电镜对心肌超微结构进行形态学观察。结果实验组中MDA含量较对照组明显升高,而SOD含量及cTnI、LDH、CK、CK-MB漏出率较对照组明显降低。试验组心肌超微结构损伤程度较对照组轻。结论在心脏移植过程中应用蛇床子素注射液,可减轻移植心脏的缺血/再灌注损伤,对移植心脏功能具有保护作用,能增加心脏移植的成功率。     

参附注射液抑制兔再灌注肺组织NF-κB表达的实验研究

目的初步探讨参附注射液改善兔肺保存效果及可能的作用机制。方法16只健康家兔随机分为两组,对照组肺加入棉子糖(30mmol/L)的改良低钾右旋糖酐(LPD)液灌注及保存,实验组则将参附注射液(40mg/L)加入改良LPD液灌注及保存。在4℃保存12h后再灌注1h,测定动脉血氧分压(PaO2)、肺组织的干湿比(W/D)、肺组织中髓过氧化物酶(MPO)活性、NF-κB的表达并观察肺组织病理结构的变化。结果再灌注15min后,两组的PaO2逐渐降低,但实验组PaO2的降低程度明显低于对照组(P0.01);再灌注后,实验组的W/D和MPO也明显低于对照组(P0.01),肺组织NF-κB的表达也明显低于对照组(P0.01),肺组织病理变化较对照组轻。结论参附注射液可抑制再灌注肺组织中NF-κB的表达,减轻肺缺血再灌注损伤,改善肺功能,对兔肺具有保护作用。     

动脉粥样硬化家兔主动脉左旋精氨酸/一氧化氮途径的变化

目的　通过观察动脉粥样硬化家兔主动脉一氧化氮 (NO)产生及主动脉左旋精氨酸 (L Arg)转运的变化 ,探讨动脉粥样硬化疾病发生的可能机制。方法　 12只家兔分为高脂组及对照组 ,每组 6只 ,分别喂以高脂饮食及普通饮食 6周 ,取血测定血浆胆固醇 (T Chol)、甘油三酯 (TG)及低密度脂蛋白 (LDL)水平 ,测定血浆亚硝酸盐 (NO-2 )含量 ,测定主动脉孵育液中NO-2 含量及主动脉L Arg转运变化。结果　 (1)高脂组T Chol、TG及LDL水平明显高于对照组 ,分别是 18.6倍、2 .4倍及 48.8倍 (P <0 .0 1) ;(2 )高脂组血浆NO-2 含量高于对照组约 2 0 0 % (P <0 .0 1)。主动脉孵育液NO-2 含量高于对照组 17% (P <0 .0 1) ;(3)高脂组主动脉L Arg转运低亲和力Vmax较对照组增加 9倍(P <0 .0 1) ,Km较对照组增加 1.8倍 (P <0 .0 1) ;(4)高脂组主动脉总的一氧化氮合酶 (tNOS)活性较对照组显著增强 ,比对照组高 73% ,诱导性合酶 (iNOS)比对照组高约 2 0 0 % ,原生型合酶 (cNOS)比对照组低 40 % (P <0 .0 1) ;(5 )血浆精氨酸水平两组间无明显差别 (P >0 .0 5 )。结论　动脉粥样硬化时血管组织L Arg/NO系统功能紊乱 ,内皮源性cNOS活性明显降低 ,而非内皮源性的L Arg转运与iNOS活性显著增强 ;血管L Arg/NOS/NO途径的功能紊乱可能参与动脉     

老年冠状动脉旁路移植体外循环期间肺保护液灌注的肺保护作用

目的 研究体外循环期间经肺动脉灌注肺保护液对老年冠状动脉旁路移植(CABG)病人的肺保护作用.方法 将20例老年单纯CAPG病人随机分为对照组和实验组.实验组在主动脉阻断后主动脉根部灌注心脏停搏液的同时,经肺动脉灌注低温保护液,对照组则不灌注肺保护液.分别于术前、开放升主动脉后20 min、体外循环结束时采集外周动脉血,进行中性粒细胞计数;并于术前、体外循环结束后0、3、6、12 h测得动脉血氧分压(PaO2)、吸入氧浓度(FiO2),计算氧指数(PaO2/FiO2).结果 对照组在升主动脉开放20 min中性粒细胞计数较术前明显降低(P＜0.05);实验组的中性粒细胞计数在体外循环结束时明显高于术前(P＜0.05).实验组与对照组的PaO2/FiO2在体外循环结束后6 h达到最低点(P＜0.01);实验组的PaO2/FiO2在体外循环结束后12 h回升接近术前正常水平,而对照组则未回升至术前正常水平;在体外循环结束后0、3、6、12 h,实验组的PaO2/FiO2均明显高于对照组(P＜0.05,P＜0.01).实验组肺泡-动脉氧压力差(P[A-a]O2)与对照组在体外循环前无明显差别(P＞0.05),实验组再灌注60 min后P[A-a]O2与体外循环前无明显差别(P＞0.05)、明显低于对照组(P＜0.01),对照组再灌注60 min后明显高于体外循环前(P＜0.01).结论 体外循环后存在肺损伤,体外循环期间经肺动脉灌注肺保护液可明显减轻CABG患者的肺损伤.     

人参皂甙Rb1对离体肺保护的实验研究

目的　探讨人参皂甙Rb1 对离体兔肺缺血再灌注损伤的保护作用。方法　将 2 0只健康家兔随机分为两组 ,对照组肺以含PGE1 的低钾右旋糖酐 (LPD)液灌注及保存 ,实验组则将人参皂甙Rb1 (0 .0 8mg/ml)加入含PGE1 的LPD液灌注及保存 ,4℃保存 1 2h后复灌 1h ,测定肺血管阻力 (PVR)、肺静脉血氧分压 (PvO2 )及肺组织含水量 (LW) ;肺组织一氧化氮 (NO)、超氧化物歧化酶 (SOD)、丙二醛 (MDA)含量 ;用末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法 (TUNEL)对肺组织凋亡细胞进行检测并观察肺组织超微结构变化。结果　实验组PVR、LW较对照组明显降低 (P <0 .0 5 ,PvO2 明显升高 (P <0 .0 1 。肺组织NO、SOD含量明显高于对照组 (P <0 .0 5) ,MDA含量则较对照组低 (P <0 .0 5) ,实验组肺组织细胞凋亡指数亦较对照组显著减少 (P <0 .0 5) ,其超微结构变化明显较对照组轻。结论　肺保存液中加入人参皂甙Rb1 能减轻肺缺血再灌注损伤 ,增加肺保护效果     

左旋精氨酸对离体兔肺脏保存质量的影响

观察左旋精氨酸对离体兔肺脏保存的保护作用 ,健康家兔随机分成对照组 (EC组 )和实验组 (Arg组 ) ,每组 15只 ,EC组兔肺脏予Euro collins液进行灌洗 ,Arg组予含左旋精氨酸的EC液进行灌洗肺脏 ,灌洗总量 6 0ml/kg ,灌注压力 2 0cm水柱 ,灌毕完整取下心肺组织浸入保存液 4℃环境冷藏 ,7h后取肺进行离体复灌 ,测定肺血管阻力 ,血气分析 ,肺血管对Ach舒血管反应性 ,肺组织湿干重比例及肺组织电镜检查等指标。EC组肺血管阻力 ,肺组织湿干重比例均高于Arg组 ,肺血管对Ach反应性EC组较Arg组差 ,血气指标EC组下降明显 ,Arg组肺组织形态轻微改变 ,而EC组水肿明显渗出严重。左旋精氨酸具有改善离体兔肺脏的保存效果。     

犬肺原位常温缺血再灌注动物模型的建立及肺保护液的相关研究

目的 深入研究缺血再灌注对移植肺功能损害的发生机制,建立简便易操作的大动物左肺灌注模型,利用此模型探讨低钾右旋糖酐(LPD)液加硝普钠(SNP)对肺缺血再灌注损伤作用研究.方法 选用成年杂种犬12只,随机分为2组:对照组(肺缺血时用LPD液灌洗),实验组(肺缺血时用LPD液加SNP灌洗),建立左肺原位缺血模型.结果 实验组和对照组犬肺循环主肺动脉压力,左、右肺动脉压力以及肺损伤指数,血管壁水肿程度,湿干重比的差异均没有统计学意义(P＞0.05).结论 该动物模型能够较好反映缺血再灌注对犬移植肺功能的损害,为研究缺血再灌注损伤机制和肺保护液的研究提供了一种理想的动物模型.SNP加入至LPD液在肺缺血时局部灌洗没有确切的肺保护作用.     

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.