L-精氨酸对心力衰竭患者血管内皮功能的影响

目的 :评价L 精氨酸对心力衰竭 (心衰 )患者血管内皮功能的影响。方法 :应用高分辨率超声诊断仪 ,评估 40例心衰患者和 3 0例健康者 (正常对照组 )的内皮依赖性血管舒张功能和非内皮依赖性血管舒张功能 ,并测定血浆一氧化氮、内皮素 1(ET 1)浓度。 40例心衰患者被随机分为 2组 ,每组 2 0例 ,分别予以 2 0 %L 精氨酸注射液 10 0ml(L 精氨酸治疗组 )和 5 %葡萄糖注射液 10 0ml(安慰剂组 ) ,均在 60min内恒速静脉滴注。随即再次评估内皮依赖性血管舒张功能和非内皮依赖性血管舒张功能 ,同时复测血浆一氧化氮和ET 1浓度。结果 :与正常对照组相比 ,心衰患者内皮依赖性血管舒张功能显著受损 (P <0 0 1) ,非内皮依赖性血管舒张功能无明显变化 (P >0 0 5 )。血浆一氧化氮浓度下降 ,ET 1浓度上升 (P均 <0 0 1)。L 精氨酸治疗组内皮依赖性血管舒张功能得到明显改善 (P <0 0 5 ) ,非内皮依赖性血管舒张功能无变化 (P >0 0 5 ) ,血浆一氧化氮浓度升高 ,ET 1浓度下降 (P均 <0 0 5 )。而安慰剂组均无显著变化 (P >0 0 5 )。结论 :L 精氨酸能改善心衰患者血管内皮功能。     

一氧化氮对自发性高血压大鼠血管内皮功能的作用

目的　探讨自发性高血压大鼠 (SHR)内皮舒张功能不全的发生机制。方法　采用体外灌注的方法测定大鼠胸主动脉环对不同浓度乙酰胆碱的舒张反应变化 ,并测定血清中NO-3浓度和动脉组织中环鸟苷酸水平。结果　与魏 凯二氏大鼠 (WKY)比较 ,SHR胸主动脉环对乙酰胆碱的舒张反应明显减弱。左旋硝基精氨酸 (L NNA)可明显抑制大鼠胸主动脉环对乙酰胆碱的舒张反应 ,但并不能消除SHR和WKY对乙酰胆碱舒张反应之间的差异。与WKY比较 ,SHR血中NO-3水平明显降低 (P<0 .0 1) ,动脉组织中环鸟苷酸含量降低 (P<0 .0 1)。结论　SHR内皮依赖的血管舒张功能减低 ;一氧化氮 (NO)的生成或释放不足可能直接参与了SHR血管内皮依赖的舒张功能不全。     

血脂康对高脂血症患者血管内皮功能的影响

为探讨血脂康对高脂血症患者血管内皮功能的改善作用 ,5 8例高脂血症患者随机分为两组 ,分别给予血脂康或安慰剂治疗 8周 ,利用高分辨率超声测定血流介导的肱动脉舒张及其对硝酸甘油的反应 ,并观察血脂变化。结果显示 ,两组治疗前血脂水平相似 ,血脂康治疗后血清总胆固醇、低密度脂蛋白胆固醇和甘油三酯分别下降2 1 5 %、2 8 2 %和 16 2 % ,血流介导的血管舒张显著增加 (P <0 0 1) ,而安慰剂治疗组无显著差异。两组硝酸甘油介导的舒张相似 ,治疗前后均无显著差异。以上表明 ,血脂康可降低高脂血症患者血清总胆固醇、低密度脂蛋白胆固醇和甘油三酯水平 ,改善高脂血症患者的血管内皮功能     

苯那普利对自发性高血压大鼠血管内皮舒张功能的改善作用

目的 :探讨苯那普利能否改善自发性高血压大鼠 (SHR)血管内皮舒张功能。　　方法 :采用体外灌注法测定苯那普利治疗组 (治疗组 )及对照组胸主动脉环对乙酰胆碱的舒张反应 ,并比较两组血清中 NO3- 浓度、动脉组织中环鸟苷酸 (c GMP)水平。　　结果 :与对照组比较 ,治疗组胸主动脉环对乙酰胆碱的最大舒张反应明显增强 (P<0 .0 1)。左旋硝基精氨酸 (L-NNA)几乎完全消除了治疗组和对照组舒张反应之间的差异。治疗组血清 NO3-浓度和动脉组织 c GMP的含量均明显增加 (P均 <0 .0 1)。　　结论 :苯那普利长期治疗可明显改善 SHR血管内皮舒张功能 ,其机制可能是增加了内皮一氧化氮的合成或释放     

海带多糖对心理应激大鼠血管内皮依赖性舒缩功能的影响

目的 研究海带多糖对心理应激大鼠血管内皮依赖性舒张和收缩功能的影响.方法 采用空瓶刺激法建立心理应激大鼠模型,大鼠随机分为对照组、模型组、海带多糖低剂量组、海带多糖高剂量组及低分子肝素组.经旷场试验后,取胸主动脉置于恒温灌流系统,分别记录血管环在累积浓度乙酰胆碱、去甲肾上腺素诱导后的血管舒缩反应,以及一氧化氮合酶抑制剂(左旋硝基精氨酸甲酯)孵育后累积浓度硝酸甘油的血管舒张反应情况.结果 模型组、海带多糖低剂量组、海带多糖高剂量组和低分子肝素组旷场行为学评分显著高于对照组(P＜0.05).与对照组比较,模型组对乙酰胆碱诱导的血管舒张反应明显降低(P＜0.05),对去甲肾上腺素诱导的血管收缩反应明显增强(P＜0.05);与模型组比较,海带多糖高剂量组对乙酰胆碱诱导的血管舒张反应明显增强(P＜0.05),对去甲肾上腺素引起的血管收缩反应明显减弱(P＜0.05),海带多糖低剂量组和低分子肝素组血管舒缩反应无显著性变化(P＞0.05).左旋硝基精氨酸甲酯孵育后,与对照组比较,模型组、海带多糖低剂量组、海带多糖高剂量组和低分子肝素组对硝酸甘油引起的舒张反应均显著降低(P＜0.05),海带多糖高剂量组、海带多糖低剂量组和低分子肝素组加入左旋硝基精氨酸甲酯孵育后硝酸甘油诱导的血管最大舒张反应显著低于乙酰胆碱诱导(未加入左旋硝基精氨酸甲酯孵育)的血管最大舒张反应.结论 海带多糖对心理应激大鼠血管内皮依赖性舒缩功能具有保护作用.因此,海带多糖可以拮抗内源性肾上腺素增多导致的内皮损伤.     

高血压对冠心病患者血管内皮功能影响的研究

目的　探讨高血压对冠心病患者血管内皮功能的影响。方法　通过检测 38例单纯冠心病患者 (A组 )、5 2例冠心病合并高血压病患者 (B组 )、12例健康对照组 (C组 )的肱动脉舒张功能 :反应性充血后血管舒张 (FMD)、含服硝酸甘油后的血管舒张 (NID)及血内皮素 (ET)、一氧化氮 (NO)等指标并进行对比分析。结果　 (1)FMD、ET :A、B组较C组均有显著差异 (均P <0 0 1) ;(2 )NO :B组较C组明显降低 (P >0 0 5 ) ;(3)A、B组间 :FMD、ET、NO均有显著差异 (均P <0 0 5 ) ;(4 )NID在三组间无差异 (P <0 0 5 ) ;(5 )FMD :与NO呈正相关 (r=0 4 3,P <0 0 1) ,与SBP、LDL、ET呈负相关(r =- 0 5 2、- 0 36和 - 0 4 7,均P <0 0 1) ;SBP :与LDL、ET呈正相关 (r =0 2 5和 0 4 2 ,P <0 0 5 ) ,与NO呈负相关 (r<- 0 31,P <0 0 1)。结论　冠心病患者存在显著的内皮依赖性舒张功能障碍 ;高血压病加重冠心病患者的内皮依赖性舒张功能障碍 ;FMD与NO、ET均可作为反映冠心病和高血压病者血管内皮功能的无创指标。     

高尿酸血症对血管内皮功能影响的观察

目的　观察高尿酸血症对血管内皮功能的影响。方法　对 30例高尿酸血症男性患者和 30例正常男性采用高分辨超声技术检测血流介导和硝酸甘油介导的肱动脉舒张功能 ,并测定血浆内皮素和一氧化氮。结果　 (1)高尿酸血症患者血流介导的肱动脉舒张较正常组明显减弱 (P <0 0 1) ,而两组对硝酸甘油的血管舒张反应差异无显著性 (P >0 0 5 ) ;(2 )高尿酸血症患者血浆内皮素水平显著高于正常组 (P <0 0 1) ;一氧化氮水平显著低于正常组 (P <0 0 5 )。结论　高尿酸血症患者内皮依赖性血管舒张功能明显受损 ,血管内皮功能失调可能是高尿酸血症致动脉粥样硬化的一个重要机制。     

高胆固醇血症对离体兔主动脉血管内皮依赖性舒张反应的影响

目的 :探讨高胆固醇血症对血管内皮依赖性舒张反应的影响。　　方法 :2 0只新西兰雄性兔随机分为两组 :正常对照组 (10只 )及高胆固醇血症组 (10只 )。4周后取出每只兔的降主动脉 ,5 mm宽的动脉环放置于含有 2 5 ml Kreb液的组织—器官水浴系统中。分别测量游离血管对乙酰胆碱 (10 - 1 0 ～ 10 - 5mol/ L )和腺苷 (10 - 1 0 ～ 10 - 4 mol/ L )的舒张反应变化 (% )。　　结果 :两组血胆固醇水平有显著差异 (正常对照组 0 .78± 0 .2 9mmol/ L ,高胆固醇血症组 2 5 .6 7± 2 .86 mmol/ L ,P<0 .0 1) ;高胆固醇血症组血管对乙酰胆碱舒张反应〔最大 (5 8.2± 6 .1) %〕与正常对照组〔最大 (10 3.2± 6 .9) %〕比较明显减弱 (P<0 .0 1) ;高胆固醇血症组血管对腺苷舒张反应〔最大 (4 5 .2± 13.0 ) %〕也较正常对照组〔最大 (10 3.2± 9.9) %〕减弱 (P<0 .0 1)。两组动脉组织学检查无动脉硬化的改变。　　结论 :高胆固醇血症降低血管内皮依赖性舒张反应 ;高胆固醇血症时血管内皮功能改变早于动脉粥样硬化的结构改变。     

微粒化非诺贝特对高三酰甘油血症患者血管内皮功能的作用

目的 :探讨微粒化非诺贝特对高三酰甘油血症患者血管内皮功能的作用。方法 :对 30例高三酰甘油血症患者 (口服微粒化非诺贝特 2 0 0mg/d治疗 4周前后 )和 30例正常人采用高分辨超声技术检测血流介导的和硝酸甘油介导的肱动脉舒张功能 ,并测定血浆内皮素 (ET)和血脂。结果 :①高三酰甘油血症组血流介导的肱动脉舒张反应较正常组明显减弱 [(2 .7± 2 .0 ) %∶(15 .0± 8.0 ) % ,P <0 .0 1],而两组对硝酸甘油的血管舒张反应差异无显著性意义 [(15 .0± 5 .0 ) %∶(16 .8± 9.0 ) % ,P >0 .0 5 ]。②高三酰甘油血症患者微粒化非诺贝特治疗后血流介导的肱动脉舒张显著改善 [(11.0± 9.0 ) % ,P <0 .0 1],而硝酸甘油介导的血管舒张较治疗前无明显改变[(16 .2± 6 .0 ) % ,P >0 .0 5 ]。③高三酰甘油血症患者血浆ET水平显著高于正常人 [(10 6 .2± 19.2 ) μg/L∶(72 .4± 14 .1) μg/L ,P <0 .0 1],微粒化非诺贝特治疗后血浆ET水平显著降低 [(82 .7± 15 .5 ) μg/L ,P <0 .0 1],血清三酰甘油明显降低 (P <0 .0 5 )。结论 :微粒化非诺贝特对高三酰甘油血症患者受损的血管内皮依赖性舒张功能有改善作用。改善血管内皮功能亦是微粒化非诺贝特防治冠心病的作用机制之一     

冷应激高血压大鼠血管舒缩功能的研究

目的　探讨寒冷环境因素在大鼠高血压发病中的作用。方法　 40只 3月龄雄性Wistar大鼠 ,随机分成寒冷组和对照组 ,寒冷组动物置于 4± 2℃的冷环境中 ,每天 4小时 ,共 8周。每周测鼠尾血压、心率、体重。 8周后取胸主动脉完整血管环 ,生理多导记录仪分析血管活性物质对离体血管环舒缩功能的影响。结果　寒冷组的鼠尾压、心率均明显升高 (P <0 0 1 ) ,四周鼠尾血压达到最高 (为 1 36 .4± 5 .5mmHg)。血管环功能实验表明 ,冷应激组大鼠血管环对AngⅡ、NE、NTG的反应性与正常组无差别 ,但对钙通道开放剂 (Bayk 8644)的收缩反应明显增强 (P <0 0 1 )及Ach引起的内皮依赖的舒张反应明显减弱 (P <0 0 5)。结论　冷应激环境因素刺激可导致大鼠高血压和血管功能异常 ,其机制可能与钙通道异常开放和内皮依赖的舒张功能受损有关     

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.     

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.     

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.     

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.