贝那普利对快速心房起搏家兔心房电重构的影响

目的 观察贝那普利对8h心房快速起搏家兔心房电重构(AER)的影响。方法取12只家兔,随机分为二组,对照组(生理盐水15ml/d),贝那普利组[5mg/(kg·d)溶于15ml生理盐水中],灌胃2周。①分别于起搏前、中、后测刺激频率为200ms、150ms时心房有效不应期(AERP200、AERP150)。②取未起搏家兔及每组起搏8h后家兔右心耳组织观察超微结构。结果①8h心房快速起搏使对照组家兔AERP缩短,AERP频率自适应性出现了下降—消失—逆转,心房肌超微结构可见线粒体肿胀、嵴溶解,糖原聚集;停止起搏后30min AERP及AERP频率自适应性基本恢复。②贝那普利组家兔心房快速起搏8h过程中各观测点AERP较起搏前无明显变化,家兔心房肌细胞超微结构基本正常。结论①心房快速起搏8h可致AER和心房肌细胞发生超微结构改变。②贝那普利可以阻止心房快速起搏8h所致AER及心房肌超微结构改变。     

家兔快速心房起搏所致电重构和解剖重构及其时间进程的研究

对家兔短期快速心房起搏所致的心房肌电重构和解剖重构特征和时间进程加以研究。 2 0只家兔经颈内静脉切开置入电极导管定位于右房 ,以最快的心房 1∶1起搏频率行快速心房起搏 8h ,分别于起搏前、起搏后 0 .5 ,1,2 ,4 ,6 ,8h及停止起搏后 10 ,2 0 ,30min测定心房有效不应期 (AERP) ,并分别取未起搏 ,起搏 4 ,8h家兔的右心耳组织 ,观察其超微结构。结果 :快速心房起搏后AERP缩短 ,刺激频率 2 0 0 ,2 5 0ms的AERP的最小值出现在快速心房起搏后 1h ,起搏后 0 .5h内AERP变化速率最大 ,在其后的整个短期起搏过程中在较低水平波动 ,停止起搏 10min即可恢复 95 %以上。快速心房起搏 4 ,8h后心房肌细胞超微结构可见线粒体肿胀 ,糖原聚集 ,肌浆网和胞核无明显变化。结论 :短期快速心房起搏可导致心房肌电重构 ,以AERP缩短为特征的电重构在起搏后 0 .5h即可发生 ,其时间进程表现为发生快 ,短期起搏停止后逆转快的特点 ,短期的快速心房激动可导致心房肌细胞超微结构的改变     

胺碘酮或氯沙坦及两者合用对急性心房颤动患者心房重构的干预

目的:采用人工心脏起搏的方法制备家兔急性心房颤动模型,分别探讨胺碘酮与氯沙坦对心房颤动导致心房重构的不同干预效果.方法:40只家兔随机分为0.9%氯化钠溶液组(对照组)、胺碘酮组、氯沙坦组、合用组,分别灌胃给药1周,以600次/min的频率起搏心房8 h,并分别于起搏前、起搏后0.5、1、2、4、6、8 h及停止起搏后10、20、30 min重复测定心房有效不应期(AERP).结果:①经过8 h快速起搏后对照组AERP200(100.63±7.5)ms和AERP150(95.01±6.2)ms均较起搏前明显缩短(均P＜0.01),AERP200较AERP150缩短更为明显(P＜0.05),胺碘酮组、氯沙坦组及合用组快速起搏前后AERP无显著变化.②停止快速起搏后,对照组AERP逐渐恢复,AERP200和AERP150在10 min内基本恢复至起搏前的95.78%和96.76%,30 min内基本恢复至起搏前的99.07%和99.39%.结论:短期快速心房起搏可致心房电重构;胺碘酮和氯沙坦可以逆转心房电重构.     

奥美拉唑对家兔心房电重构的影响

目的探讨质子泵抑制剂奥美拉唑对心房快速起搏所致家兔心房电重构的影响。方法24只家兔随机分为4组:生理盐水组、奥美拉唑组、生理盐水+起搏组和奥美拉唑+起搏组。其中生理盐水+起搏组和奥美拉唑+起搏组,分别在静脉注射生理盐水和奥美拉唑后,以最快的心房1∶1起搏频率（500～600次/min）行快速心房起搏3h,分别于起搏前、起搏后0.5、1、1.5、2、2.5和3h测定基础刺激周长分别为200ms和150ms时右心房有效不应期（AERP）,并分析AERP的频率适应性。结果单纯注射生理盐水或奥美拉唑,AERP和其频率适应性无显著改变。心房快速起搏使生理盐水+起搏组的AERP200及AERP150较起搏前显著缩短（P<0.05）,频率适应性的指标（AERP200-AERP150）/50ms显著缩短（P<0.01）。而奥美拉唑+起搏组的AERP和频率适应性未发生显著变化。结论奥美拉唑对心房不应期无直接影响,但可有效防止心房快速起搏引起的心房电重构。     

粉防已碱对家兔快速心房起搏所致电重构的影响

为探讨家兔快速心房起搏所致的心房肌电重构的机制及粉防已碱对其影响 ,32只家兔随机分为三组 :正常对照组 (A组 ,n =8) ,快速心房起搏组 (B组 ,n =12 ) ,快速心房起搏 +粉防已碱组 (C组 ,n =12 )。经颈内静脉将电极置入右房 ,以 6 0 0次 /分行快速心房起搏 ,测定基础状态、给药后 0 .5h和起搏后 0 .5 ,1,2 ,4 ,6 ,8h ,S1S1为 2 0 0 ,15 0 ,130ms时的心房有效不应期 (AERP2 0 0 、AERP150 和AERP13 0 ) ,实验结束后取三组兔的右心耳组织 ,检测心肌细胞内Ca2 + 含量 ,观察心肌细胞超微结构。结果 :快速心房起搏后B组的AERP缩短 ,AERP的频率适应不良 ,心肌细胞内Ca2 + 含量增加 ,同基础状态比较差异有显著性 (P <0 .0 1) ,心房肌细胞损伤的超微结构变化明显 ,在C组粉防已碱抑制了快速起搏引起的心肌细胞Ca2 + 增加 ,AERP缩短和频率适应不良减轻。结论 :心房肌细胞内Ca2 + 水平的增高在快速起搏导致的心房肌电重构中起作用 ,粉防已碱能减轻快速心房起搏所致的电重构。     

丹参酮ⅡA磺酸钠对家兔快速心房起搏时心房动作电位及有效不应期的影响

研究丹参酮ⅡA磺酸钠(TSN)对家兔短期快速心房起搏时在体心房单相动作电位(AMAP)及心房有效不应期(AERP)的影响,探讨其防治心房颤动的可能机制。家兔24只,随机分为对照组与TSN组各12只。将电极经颈内静脉置入右房记录AMAP,观察基础状态下、给药后0.5h及以600次/分心房快速起搏后0.5,8hAMAP及其频率适应性的变化。结果:与起搏前相比对照组在S1S1200ms刺激时测量的AERP(AERP200)在起搏后0.5h缩短21.2ms,起搏后8h缩短21.6ms(P<0.05),且心房肌的频率适应性丧失。TSN在基础状态下对AMAPA、AMAPD无明显影响,但使AERP200由105.9±3.8ms延长至114.7±7.2ms(P<0.05)。起搏后TSN组维持原有的心房肌频率适应性。结论:快速心房起搏使心房肌的频率适应性丧失而致电重构,TSN能减轻短期快速心房起搏所致电重构。     

心脉隆注射液对家兔快速心房起搏心房电重构的影响

目的观察心脉隆注射液对家兔快速心房起搏心房电重构的干预效果。方法选取健康成年家兔28只,随机分为心脉隆注射液组、生理盐水组,每组14只。心脉隆注射液组以心脉隆注射液5 mg/kg每日08:00、16:00耳缘静脉输注给药5 d。生理盐水组以等容量的生理盐水耳缘静脉输注给药5 d。用BL-420生物机能实验系统分别测量两组家兔心房快速起搏前的心房有效不应期(AERP),然后以600次/min的频率对两组家兔分别进行快速心房起搏,测定起搏6 h后的AERP。结果生理盐水组快速起搏6 h后AERP200和AERP150较起搏前缩短,与基础状态时比较差异有统计学意义(P 0.05)。心脉隆注射液组快速起搏6 h后AERP200和AERP150较起搏前无明显缩短,与基础状态下比较差异无统计学意义(P0.05)。结论心房快速起搏可以使心房发生电重构;心脉隆注射液可以预防快速心室率引起的心房电重构。     

应用BL-420生物机能实验系统制作急性心房颤动动物模型

目的探讨应用BL-420生物机能实验系统制作急性心房颤动(房颤)动物模型的方法,并研究房颤的心房电重构现象。方法 20只家兔分别应用BL-420生物机能系统电刺激仪以600次/mln的频率起搏心房8 h,并分别于起搏前、起搏后0.5、1、2、4、6、8 h及停止起搏后10、20、30 min重复测定心房有效不应期(AERP)。结果(1)经快速起搏8 h,2例成功诱发房颤,并成功复制了房颤时的电重构现象。(2)经过8 h快速起搏后AERP在起搏最初30 min内即开始缩短,并出现频率自适应性的降低,且心房内压力较起搏前明显升高。(3)停止快速起搏后,30 min内AERP基本恢复至基础水平。结论应用BL-420生物机能实验系统制作急性房颤动物模型简便易行,并能完全复制心房电重构现象,可以用来进行房颤的电生理研究。     

胡椒碱对兔心房电重构的影响

目的探讨回心草活性成分胡椒碱对心房快速起搏诱发的兔心房急性电重构的预防作用。方法选择新西兰白兔18只,随机分成对照组、心房快速起搏组和胡椒碱+心房快速起搏组(胡椒碱组),每组6只。对照组和心房快速起搏组术前生理盐水3ml/(kg.d)灌胃3d,胡椒碱组术前给予胡椒碱20mg/(kg.d)药物灌胃3d。对照组术中不行心房快速起搏,心房快速起搏组和胡椒碱组术中以最快能维持心房11起搏频率(500～600/min)行快速心房刺激3h,分别于起搏前和起搏后0.5、1.0、1.5、2.0、2.5和3.0h时,测定基础刺激周长分别为200ms和150ms的右心房有效不应期(atrial effective refractory period,AERP),分析AERP频率适应性的变化情况。结果对照组和胡椒碱组AERP200和AERP150随时间无明显变化。心房快速起搏组AERP200和AERP150与心房快速起搏持续时间呈负相关(r=-0.674,P<0.01;r=-0.543,P<0.01),分别在2.0h和2.5h达到最低值(P<0.05)。心房快速起搏组AERP频率适应性与心房快速起搏时间呈负相关(r=-0.307,P<0.05),对照组和胡椒碱组AERP频率适应性均无明显变化。仅在心房快速起搏组可诱发出阵发性心房颤动(房颤),房颤诱发率为50%,平均房颤持续时间为9.3min。结论胡椒碱能够预防心房快速起搏引起的心房电重构。     

氯沙坦对家兔快速心房起搏心房电重构及L-型钙通道的影响

目的:通过人工心脏起搏的方法制备家兔急性心房颤动(Af)动物模型,探讨Af时心房发生电重构的机制,并观察氯沙坦对电重构的影响.方法:30只家兔,随机分为3组(每组10只):对照组、0.9%氯化钠起搏组、氯沙坦起搏组;以600次/min的频率起搏心房8 h,并分别于起搏后2、4、6、8 h测定心房有效不应期(AERP)变化及L-型钙通道的电流密度.结果:①经快速起搏8 h,0.9%氯化钠起搏组较对照组各个基础周长下的AERP均显著下降.氯沙坦起搏组较对照组AERP无明显变化.②0.9%氯化钠起搏组较对照组心房肌ICa-L降低;氯沙坦起搏组较对照组心房肌ICa-L未见显著降低;氯沙坦起搏组较0.9%氯化钠起搏组心房肌ICa-L差异无统计学意义,但ICa-L的标准差显著降低.结论:①快速心房起搏可引起AERP缩短及AERP频率适应性不良为特征的心房肌电重构,氯沙坦可以预防电重构的发生.②快速心房起搏可以导致心房肌ICa-L的降低和离散度的增高;氯沙坦可以抑制ICa-L离散度的增加从而降低Af的潜在危险.     

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.