心肌缺血时迷走神经对房室传导调节功能的研究

研究右冠状动脉阻塞时迷走神经对房室传导调节功能的影响。在离断自主神经的猫上,剌激双侧迷走神经,在结扎右冠状动脉造成缺血前后,通过模板匹配方法检测心腔的心房波,His束波和心室波,并自动测量AA,AH,HV间期。结果:在正常及缺血状态下,剌激迷走神经均可使AA、AH间期增大,HV间期不变,在起搏控制心率的情况下,这种作用更加明显。在正常供血时,剌激迷走神经使AH间期在未起搏与起搏时分别增加14%±5%和22%±7%;而在缺血时,剌激迷走神经使AH间期在未起搏与起搏时增加18%±7%和38%±14%,后者比前者提高了增加幅度的28%和73%(P<0.05)。结论:在急性右冠状动脉阻塞时,迷走神经对心脏房室传导调节功能增强。     

心房起搏脉冲传导延迟患者AV问期的优化

目的探讨心房起搏至心房除极波时间延迟患者设置起搏的房室间期（PAV）的方法及远期心房起搏的有效性。方法分析2005年1月至2012年12月我院起搏器植入后发生心房起搏至心房除极波时间延迟≥lOOms的患者10例,病窦综合征（SSS）患者的房室间期设置为最大值,并最大限度开启房室问期滞后功能;对房室传导阻滞（AVB）患者设置PAV的值为：140～180ms＋心房起搏至心房除极波延迟时间,不开启AV滞后。结果经1个月至7年随访,5例SSS患者心室起搏比例〈10％,3例SSS患者心室起搏比例30％。50％,Holter显示心室起搏时为假性融合波,l例SSS患者及1例AVB患者为心室起搏心律,起搏比例〉99％,保证了房室问期的生理性。10例患者心房起搏阈值均〈1．5／0．4ms,未发生心房起搏阈值增高及失夺获。结论心房起搏至心房除极波时间延迟患者远期的心房起搏夺获是安全的;设置起搏器PAV间期要将心房起搏至心房除极波延迟时间计算其中,程控随访中应注意观察程控仪中监护图的心房波,房室传导阻滞患者可延长房室间期后观察心房波,部分患者因监护导联显示不清,需要通过12导联心电图进行观察,避免心房起搏至心房除极波延迟病例被遗漏．导致增加心室起搏及非生理性的房室间期。     

急性下壁心肌梗死伴房室传导阻滞与冠状动脉病变的关系

目的 :探讨急性下壁心肌梗死伴房室传导阻滞 （AVB）病变过程与冠状动脉病变的关系。方法 :观察 16例急性下壁心肌梗死患者并发 AVB的形式和演变过程 ,并结合冠状动脉造影进行分析。结果 :发生 度 AVB1例 , 度 型 AVB3例 , 度 AVB12例。房室传导障碍出现的过程多数为 度、 度 型、 度 型、 度 AVB,发生时间6 4± 45 h;而恢复过程多数为 度、 度 型、 度 型、 度 AVB,恢复时间 2 2 1± 12 7h。AVB发生期 8例中有 7例优势型冠状动脉完全阻塞 ,而 AVB恢复期 8例中仅 2例优势型冠状动脉完全阻塞 （P<0 .0 1）。结论 :急性下壁心肌梗死伴房室传导阻滞的产生与恢复是优势型冠状动脉阻塞与再通的结果     

起搏心电图中的房室间期（1）

双腔起搏器及三腔起搏器的计时间期中有一个重要参数—一房室间期（也称房室延迟）。房室间期是心房事件与心室刺激脉冲之间的问期,是起搏器设定的房室传导时间,与自主心律中的P—R间期相当。房室间期分为感知和起搏两种,前者为心房感知事件与心室起搏脉冲的间期,     

预激旁道参与的房室折返性心动过速

预激综合征患者不论旁道位于左侧还是右侧,常可发生顺向型房室折返性心动过速。心动过速的折返环路中,正常的房室传导系统为房室间的前传支,旁道为房室间的逆传支,心房和心室都是折返环的必需成分。顺向型房室折返性心动过速时的心室除极顺序正常,QRS波时限<0.11s,属于窄QRS波心动过速。心动过速时的RR间期为下述两个间期之和:①AV间期(PR间期):从P波开始到R波开始,代表房内传导时间、房室结传导时间、希浦系传导时间三者之和,称为房室前向传导时     

DDD起搏最佳房室延迟的设置及血流动力学评价

目的 对不同房室延迟DDD起搏患者进行血流动力学评价,探讨DDD起搏最佳房室延迟的设置方法。方法 应用超声心动图研究17例植入DDD起搏器患者不同AV间期时心排出量（CO）、舒张期二尖瓣返流（DMRD）、A波结束至二尖瓣完全关闭时间间期及同步心电图QT间期等的变化。结果（1）当 AV延迟调至（16.9±19.9）ms时,A波结束与二尖瓣关闭同时出现,此时将AV延迟分别延长20ms、40ms、60ms、80ms,A波结束至二尖瓣完全关闭的间期分别延长（13.9±3.7）ms、（31.5±5.1）ms、（52.8±4.1）ms、（72.4±4.0）ms,而且在此间期可发现舒张期二尖瓣返流;（2）CO最大时的AV延迟（即最佳房室延迟）与预测的最佳 AV延迟呈明显正相关（r=0.893,P<0.05）;（3）临界AV间期与最佳AV间期有显著正相关（r=0.884,P<0.05）,临界AV间期较最佳AV间期长;（4）临界AV间期及其后不同AV间期预测的最佳AV间期之间差异均无显著性（P>0.05）。结论 （1）临界AV间期可代表最佳AV间期的上限,可用临界AV间期减去A波结束至二尖瓣完全关闭的时间间期来预测最佳AV间期;（2）最佳AV延迟可按以下公式预测:先设置一个较长的AV间期,然后于超声心动图下测量A波结束至二尖瓣完全关闭的时间间期,则最佳AV间期等于此较长的AV间期减去A波结束至二尖瓣完全关闭的     

起搏心电图(Ⅴ)双腔起搏器心电图(Ⅱ)

图13设定DDD起搏器不同A-V间期值后记录的心电图。A.心室起搏信号夺获心室，B.心室起搏信号后的QRS波群为心室融合波群（包括房室结下传激动心室的成分），C.心室起搏信号消失，心房激动沿房室结下传激动心室。三、DDD起搏器类房室结传导功能的心电图表现如前所述，DDD起搏器具有类房室结的传导功能，植入后可使患者原有的三度房室传导阻滞消失（图5）。DDD起搏器类房室结传导功能具有多方面含义，这些功能特点在其心电图上都有相应的表现。1.DDD起搏器类房室结传导的房室传导间期。起搏器房室传导间期（A-Vinterval，AVI）代表…     

右侧显性房室旁道合并右后隔慢旁道的电生理特点和消融治疗

报道两例右侧显性房室旁道合并右后隔慢旁道的电生理特点和消融治疗。两例显性预激综合征接受射频消融治疗 ,心房和心室程控刺激评价消融前后电生理变化。心脏标测证实两例病人存在右侧显性房室旁道 ,阻断该旁道后AV间期延长达 16 3和 16 7ms,QRS波群变宽呈完全预激形 ,程控刺激和标测证实为右后隔慢旁道 ,前传速度慢但无递减传导 ,无VA传导 (例 1)或VA递减传导 (例 2 )。消融阻断慢旁道后AV再次延长达 188ms和 2 17ms,心室预激消失 ,QRS波群呈右束支阻滞形 ,心室刺激见VA分离。结论 :两例病人为右侧游离壁显性房室旁道合并右后隔慢旁道 ,前者掩盖后者的前向传导。正常房室传导束 (AVN HPS)的传导速度慢于慢旁道是其显现前传的原因。     

房室传导阻滞心电图分析中应注意的几个问题

心电图中房室传导功能通常以P波与QRS波群的关系作为评价依据。当每个P波都能下传心室,且P-R间期正常时,判定为房室传导功能正常。每个P波都能下传心室,但P-R间期大于正常范围,诊断为一度房室传导阻滞。部分P波不能下传心室时,诊断为二度房室传导阻滞。此时,如下传P-R间期逐次延长,诊断为二度I型房室传导阻滞;如间期固定,诊断为二度Ⅱ型房室传导阻滞;如房室传导比例大于3∶1,诊断为高度房室传导阻滞;如为不完全性房室分离仅偶有夺获,诊断为几乎完全房室传导阻滞。P波与QRS波群完全无关(完全性房室分离),且心房率大于心室率,心室为逸…     

对心室起搏管理的再认识

心室起搏管理(MVP)这一功能为美敦力公司开发,MVP模式下,双腔起搏器的基本起搏模式为AAI(R),但起搏器的心室通道具有感知功能和备用起搏功能,起搏模式可以在AAI(R)和DDD(R)之间转换。在AAI(R)起搏模式下,单个心房激动未下传激动心室并不触发起搏器发生模式转换,也不触发起搏器发放心室脉冲(VP),心室备用脉冲的发放时间为心房逸搏间期计时结束后的80 ms处;如果连续4个P波中有2个不能下传激动心室,则AAI(R)起搏模式将自动转换为DDD(R)起搏模式。MVP功能进行自身房室传导搜索时的心室漏搏会增加患者的不适,心室漏搏造成的长短周期序列可能会诱发心律失常,即使起搏器能搜索到自身房室传导,但如果自身房室传导间期过长,则失去了房室顺序收缩对心输出量的改善。如存在心房起搏功能或心房感知功能不良会造成房室不同步。病窦综合征患者植入有MVP功能的起搏器后,AAI(R)起搏模式下如果心房通道发生超感知,会导致心室漏搏。MVP功能打开时会抑制心室安全起搏功能发挥作用。如室性早搏或交界区早搏的QRS波位于心房起搏后80 ms内,不会被起搏器感知,使起搏器判断错误,起搏器误认为心室发生了漏搏,触发心室备用脉冲在心房逸搏间期结束后80 ms处发放。上述缺点限制了MVP功能在临床上的使用,如能对MVP功能做一改进,进行自身房室传导搜索时如果在两个心房事件间期的50%处或心房事件后一定时间处(如350 ms时)仍未搜索到自身房室传导时,起搏器发放心室备用脉冲,可能会减少MVP的不良影响,这一改进和AV Search的区别在于房室搜索是逐渐延长还是突然延长。     

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.