心脏脂肪垫在肺静脉灶性放电引发心房颤动中的作用

探讨心脏脂肪垫在肺静脉灶性放电与心房颤动 (简称房颤 )中的作用。 14条狗麻醉后经右侧开胸暴露右侧肺静脉。将 8极电极标测导管缝在右上肺静脉用于起搏。另放一 8极电极导管固定在临近右肺静脉和左房交接处脂肪垫。术中监测ECG的II和aVR导联、血压和体温。以 0 .1ms刺激间期 ,2 0Hz刺激频率的直方波刺激脂肪垫的迷走神经丛 30～ 5 0s,随着电压从 1～ 4 .5V ,心率逐渐减少 (P <0 .0 5 ) ,同时出现房性早搏、房性心动过速和房颤。在刺激迷走神经丛的同时 ,以 2 0 0～ 80 0次 /分的频率刺激肺静脉 (对照组没有迷走神经丛刺激 )均能诱发房颤。在迷走神经丛刺激下 ,以S1S1330ms,S1S2 稍长于肺静脉不应期的配对间期刺激肺静脉诱发房颤。与对照组比较 ,在迷走神经刺激下 ,肺静脉刺激诱发房颤的房性早搏数 ,随着刺激电压从 0 .6到 3V的增加 ,从 7个减少到 2个 (P <0 .0 5 )。 7条狗局部去神经后 ,6条狗在同样肺静脉刺激诱发房颤的电压条件下不能诱发房颤 ,其中有 3条在电压大于 9V时诱发房颤。结论 :在临近右肺静脉和左房交接处脂肪垫刺激可以将肺静脉灶性放电转变成房颤。因此 ,临床上自发的迷走神经丛的张力增高是肺静脉灶性放电转变成房颤的基础。     

窦房结脂肪垫对犬右上肺静脉电生理特性影响的研究

目的研究不同水平刺激窦房结脂肪垫(SANFP)对右房(RA)及右上肺静脉(RSPV)的有效不应期(ERP)及心房颤动(简称房颤)诱发率的影响,探讨SANFP对房颤发生维持的作用。方法6只犬麻醉后经右侧开胸暴露RSPV及SANFP,以0.6～2,5,8mV三种不同电压强度水平、60ms频率刺激SANFP,同时以S1S2刺激观察三种水平下RA游离壁远、中、近端及RSPV远、中、近端ERP的变化;同样方法刺激SANFP以S1S1和S1S2程序刺激诱发房颤,测定房颤的诱发率。结果以5mV电压刺激窦房结脂肪垫RSPV近端ERP较基础时明显缩短(90±24msvs109±16ms,P<0.05),其房颤诱发率50%;以5,8mV电压刺激SANFP时RA游离壁近端、中端ERP变化较基础时明显缩短(96±20msvs117±14ms,65±20msvs117±14ms,P均<0.05),其房颤诱发率100%。结论窦房结脂肪垫可能在肺静脉起源的房颤的诱发和维持中起了重要作用。     

消融犬右肺静脉脂肪垫对心房及右上肺静脉电生理特性及房颤诱发的影响

目的探讨消融右肺静脉脂肪垫对心房及右上肺静脉电生理特性及房颤诱发的影响。方法犬18只分别在颈部迷走神经未刺激和刺激的情况下,观察射频消融肺静脉脂肪垫前后心房不同部位及右上肺静脉有效不应期、房颤诱发率及房颤诱发窗口的变化。结果在刺激迷走神经的情况下,与消融前相比,消融后高位右心房有效不应期延长（P<0.05）,其余部位有效不应期无显著差异,消融后高位右心房房颤诱发率降低（P<0.01）,房颤诱发窗口变窄（P<0.05）,左心房（P<0.01）及右上肺静脉（P<0.01）房颤诱发率升高,诱发窗口增宽。同时,心房有效不应期离散度增加（P<0.01）。结论消融右肺静脉脂肪垫使高位右心房房颤诱发率降低及房颤诱发窗口变窄,却使左房、右上肺静脉房颤诱发率升高及房颤诱发窗口增宽。     

消融犬Marshall韧带对刺激心房左后脂肪垫所致心房颤动的影响及机制

目的探讨消融犬Marshall韧带对刺激心房左后脂肪垫所致心房颤动(简称房颤)的影响及机制。方法成年杂种犬14条,随机分为实验组8条,对照组6条。实验组首先测量左肺静脉和左心耳的有效不应期,继而刺激心房左后脂肪垫诱发房颤。消融Marshall韧带上段后和下段后重复上述步骤。对照组除不干预Marshall韧带外,其它电刺激方案与实验组相同,同时对该组犬的心脏进行迷走神经染色。结果①实验组消融Marshall韧带后,左肺静脉和左心耳的有效不应期均显著延长(P0.05)。②和消融前比较,实验组消融Marshall韧带上段后的房颤诱发率有下降趋势(70.8%vs87.5%,P0.05);消融Marshall韧带全程后房颤诱发率显著下降(33.3%,P0.001)。对照组三次电刺激所测得的不应期和房颤诱发率无差异。③Marshall韧带与左下肺静脉、心房左后脂肪垫、左心耳之间存在迷走神经的直接联系。结论消融犬Marshall韧带可显著降低刺激心房左后脂肪垫所致房颤的诱发率。     

起源于肺静脉的阵发性心房颤动导管射频消融治疗

目的　探讨环状电极 (Lasso电极 )标测指导起源于肺静脉的阵发性心房颤动 (房颤 )导管射频消融治疗的安全性和有效性。方法与结果　 2 0 0 1年 5～ 12月 ,12例药物治疗无效的阵发性房颤患者 ,男 8例 ,女 4例 ,平均年龄 (47 8± 14 9)岁 ,行心内电生理检查和射频消融术。在Lasso电极指导下标测肺静脉 ,以确定诱发房颤的房性早搏起源处。确定房性早搏的消融靶点后 ,在有房性早搏或冠状窦远端起搏或右心耳起搏下寻找优势肺静脉电位 (PVP)放电消融 ,或肺静脉口环状消融。消融终点设定为 :①肺静脉电位振幅明显减低或消失 ;②肺静脉自律性电位与心房电活动无关 ;③诱发房颤的房早消失。结果成功隔离 2 6条肺静脉 ;其中左上肺静脉 12条 ,右上肺静脉 8条 ,左下肺静脉 5条 ,右下肺静脉1条。有 2例仅消融 1条肺静脉 ,均为左上肺静脉 ;8例消融2条肺静脉 ,消融 3条与 4条肺静脉者各 1例。术程 (196 4±6 5 8)min ,X线曝光时间 (5 2 0± 14 4 )min。术后随访 2～ 8个月 ,有 1例频发房早发生 ,经口服胺碘酮后房早消失 ;4例有房颤短阵发作 ,其中 3例接受口服药物 (2例服用胺碘酮 ,1例服用索他洛尔 ) ,1例植入有抗房颤程序的DDDR起搏器 ,能够有效抑制房颤发作。术中选择性肺静脉造影发现 6例有轻度肺静脉狭窄 ,其     

犬左上肺静脉电刺激诱发心房颤动的电生理机制探讨

为探讨肺静脉异位电活动诱发心房颤动 (简称房颤 )的机制 ,选用 2 5只犬 ,将自制的 18导联环状标测电极置于左上肺静脉外膜上 ,从肺静脉远端采取S1S1、S1S2 两种刺激方法诱发房颤 ,记录房颤从发生到结束的全过程。结果 :2 2只犬完成试验。S1S1连续刺激、S1S2 程序刺激均可诱发房颤 ,在 2min内 3,10只犬分别被诱发 ;S1S2 诱发房颤的肺静脉标测图的特点是S2 较短 (15 2 .5± 6 .3ms) ;在S1S1持续刺激 19只犬诱发的 2 1次房颤事件中 ,有三类特征性肺静脉标测图 ,所占比例分别为 14 .2 9%、9.5 2 %、2 3.81% ,其共同点是肺静脉 左房传导速度突然递增。第一类是传导速度的递增造成心房激动的联律间期不断缩短 ,肺静脉异位刺激本身诱发房颤 ,第二、三类是传导速度的递增造成心房激动的长间歇 ,长间歇之后肺静脉异位刺激之外的逸搏或异位刺激诱发房颤。结论 :肺静脉异位刺激可使肺静脉和心房发生电重构 ,来自于肺静脉异位刺激或之外的激动可诱发房颤。     

不同配对间期房性早搏对心房电生理特性的影响

多数阵发性心房颤动(房颤)由配对间期极短的房性早搏(房早)诱发，心电图呈现P在T上现象。而配对间期稍长的房早很少能诱发房颤。这些房早多数起源于肺静脉，但在心房其它部位给予适时的房性早搏刺激也可诱发房颤，本研究意在探讨短配对间期房早及其起源部位对心房电生理特性的影响，进而寻找始动房颤的关键因素。     

经导管射频消融治疗起源于肺静脉的心房颤动（？…

报道２例经射频消融治疗成功的起源点位于肺静脉的心房颤动（简称房颤）均伴有频发房性早搏（简称房早）的阵发性房颤,电生理检查时行两次房间隔穿刺,将两根１０极标测导管通过长鞘送入左,右上肺静脉,选择性肺静脉造影证实肺静脉开口部位,静脉滴注异丙肾上腺素后１例诱发出频发房早,另１例诱发出频发房早及房颤,且房早及房颤开始发作时的心内电图无间显示最早心房激动点位于右上肺静脉内,其局部电位分别产体表心电图异位Ｐ波     

序列消融犬窦房结脂肪垫和房室结脂肪垫对迷走神经介导心房颤动诱发的影响

目的 研究旨在探索序列消融窭房结脂肪垫(sinus atrial node fat pad,SANFP)和房室结脂肪垫(atrialventricular node fat pad,AVNFP)对迷走神经介导的心房颤动(房颤)诱发的影响.方法 18只健康成年家犬分为二组,每组9只.A组优先消融SANFP,再联合消融SANFP+ AVNFP;B组优先消融AVNFP,再联合消融SANFP+ AVNFP.高频电刺激左、右侧迷走神经干制作迷走神经介导的房颤模型,测定消融前、后的房颤诱发率及心房和肺静脉不同部位有效不应期(effective refractory period,ERP).结果 (1)迷走神经干刺激可显著增加房颤的诱发率,且右侧迷走神经干刺激下的房颤诱发率高于左侧迷走神经干[(60.0±0.0)％比(18.4±22.1)％].(2)优先消融SANFP可显著降低左侧迷走神经干或右侧迷走神经干刺激下房颤的诱发率(分别降低了67.0％和72.0％),联合消融SANFP+ AVNFP可进一步降低2V电压的左侧迷走神经干或右侧迷走神经干刺激下房颤的诱发率(分别较消融前降低了100％和95.5％).而优先消融AVNFP也可显著降低2V电压的左侧迷走神经干或右侧迷走神经干刺激下房颤的诱发率(分别降低了95.7％和96.3％),但联合消融SANFP+ AVNFP并不进一步显著降低左侧迷走神经干或右侧迷走神经干刺激下的房颤诱发率(分别较消融前降低了98.0％和100％).(3)优先消融SANFP或AVNFP均可显著抑制迷走神经干刺激引起的右房、左房及右上肺静脉部位的ERP缩短效应.与单独消融SANFP相比,联合消融SANFP+AVNFP可进一步抑制迷走神经干刺激引起右房ERP的缩短效应,而联合消融AVNFP+ SANFP对迷 走神经干刺激引起左、右心房及肺静脉ERP的缩短效应的抑制作用与单独消融AVNFP比较差异无统计学意义.结论 心外膜脂肪垫消融可改变迷走神经干刺激对房颤诱发及心房肌、肺静脉ERP的影响,其中AVNFP是迷走神经干支配心房的汇聚点和主控区,因此AVNFP可能是房颤神经消融更有效的靶点.     

犬左上肺静脉电生理传导特性与孤立性心房颤动发生机制的研究

研究背景左上肺静脉是孤立性阵发性心房颤动(简称房颤)常见的放电部位,肺静脉的电活动可以传到或不传到心房,传到心房的电活动可以引起阵发性房颤,对于肺静脉内以及肺静脉-左心房间的的电传导特性的研究有助于临床消融靶点和消融终点的选择,达到提高成功率、减少并发症和降低复发率的目的.本研究初探了正常犬的左上肺静脉和与其邻近心房处的传导特性以及在迷走神经刺激下的肺静脉传导特性的改变与房颤的诱发和维持的相关性.     

Portable exhaled nitric oxide measurement: Comparison with the "gold standard" technique

Background:The measurement of fractional exhaled nitric oxide (FENO) can assist in the diagnosis of asthma and may also act as a useful surrogate inflammatory marker on which to base treatment decisions in asthma management algorithms. Until recently, this technique was confined to research facilities and secondary care institutions. A portable nitric oxide analyzer (MINO; Aerocrine AB; Smidesvägen, Sweden) has been developed, but few data exist comparing this device with established, larger laboratory-based analyzers (NIOX; Aerocrine AB).Methods:A total of 101 asthmatic patients (64 treated with regular inhaled corticosteroids) and 50 healthy volunteers had simultaneous FENO measurements undertaken using NIOX and MINO devices.Results:In both asthmatic patients and healthy volunteers, there was a good correlation between the measurements obtained using each device (r= 0.94 and 0.96, respectively). Altman-Bland plots confirmed this agreement. Receiver operating characteristic curves discriminating asthmatic patients from healthy volunteers obtained using the NIOX and MINO showed a sensitivity of 83.2% and a specificity of 72% using cutoff values of 13 and 12.5 parts per billion, respectively.Conclusion:FENO values obtained using a portable analyzer correlate well with those obtained using an established laboratory analyzer and can be used to discriminate asthmatic from nonasthmatic patients. This may facilitate the measurement of asthmatic airway inflammation in primary care.     

Microscopic-sized "microthymoma" in patients with myasthenia gravis

BACKGROUND: In 2005, Cheuk et al reported two patients with microscopic-sized thymomas and proposed the term microthymoma to distinguish it from the nodular hyperplasia of thymic epithelium, so-called microscopic thymoma. Here, we present microthymomas that were found in 196 patients with myasthenia gravis (MG) who had undergone thymectomy. MATERIALS AND METHODS: Thymic tissues in 196 patients with MG who underwent thymectomy or thymothymomectomy were examined. Of these patients, 73 patients had thymoma indicated by CT before surgery, and the other 123 patients had no mediastinal tumors. From the resected thymic tissues, an average of 14 hematoxylin-eosin-stained sections (range, 4 to 55 sections) were prepared for microscopic examination. The histologic type of the thymoma was classified according to the World Health Organization (WHO) classification. RESULTS: From the 196 patients, we found three microthymomas in 3 patients (1.5%). While these three tumors could not be seen grossly in pathology section, they were found microscopically (range, 2 to 4 mm). The histologic subtype according to the WHO classification system was B1 in one patient and B2 in two patients. CONCLUSION: Microthymoma was found in 3 of 196 patients (1.5%) with MG. Microthymoma might exist in thymus of patients with MG, even in patients who have no thymoma indicated by CT.     

"Synaptic" Ribbons in the Pineal Gland of the Horse

Previous studies on the ultrastructure of the horse pineal gland did not report the presence of "synaptic" ribbons, functionally enigmatic pinealocyte organelles regularly occurring in other mammalian species. The aim of the present study was to reinvestigate the horse pinealocyte in this respect. Careful investigations here reported allowed detection of "synaptic" ribbons in the pinealocytes of all the examined animals, although in a relatively low number (5.4 +/- 2.0 per 20,000 microns 2 of pineal tissue; mean +/- SD). The ultrastructure of "synaptic" ribbons in pinealocytes of the horse resembles closely that observed in other mammalian species.     

World Trade Center "sarcoid-like" granulomatous pulmonary disease in New York City Fire Department rescue workers

BACKGROUND: Previous reports suggest that sarcoidosis occurs with abnormally high frequency in firefighters. We sought to determine whether exposure to World Trade Center (WTC) "dust" during the collapse and rescue/recovery effort increased the incidence of sarcoidosis or "sarcoid-like" granulomatous pulmonary disease (SLGPD). METHODS: During the 5 years after the WTC disaster, enrollees in the Fire Department of New York (FDNY) WTC monitoring and treatment programs who had chest radiograph findings suggestive of sarcoidosis underwent evaluation, including the following: chest CT imaging, pulmonary function, provocative challenge, and biopsy. Annual incidence rates were compared to the 15 years before the WTC disaster. RESULTS: After WTC dust exposure, pathologic evidence consistent with new-onset sarcoidosis was found in 26 patients: all 26 patients had intrathoracic adenopathy, and 6 patients (23%) had extrathoracic disease. Thirteen patients were identified during the first year after WTC dust exposure (incidence rate, 86/100,000), and 13 patients were identified during the next 4 years (average annual incidence rate, 22/100,000; as compared to 15/100,000 during the 15 years before the WTC disaster). Eighteen of 26 patients (69%) had findings consistent with asthma. Eight of 21 patients (38%) agreeing to challenge testing had airway hyperreactivity (AHR), findings not seen in FDNY sarcoidosis patients before the WTC disaster. CONCLUSION: After the WTC disaster, the incidence of sarcoidosis or SLGPD was increased among FDNY rescue workers. This new information about the early onset of WTC-SLGPD and its association with asthma/AHR has important public health consequences for disease prevention, early detection, and treatment following environmental/occupational exposures.     

补肾益精方对切除卵巢大鼠骨质疏松模型腰椎骨生物力学性能的影响

目的：探讨被 肾益精方对去卵巢大鼠骨质疏松模型松质骨生物力学性能的影响,方法：40只10月龄Wistar雌性大鼠随机分为正常对照组,模型对照组,补肾益精方组和倍美力组,每组10只,正常对照组做假手术,其余3组做卵巢切除术,术后3个月开始给药,连续用药满90天,处死,取出第3腰椎,测定其骨质含量并进行压应力测试与分析,结果：补肾益精方组比模型组腰椎骨的骨质含量提高了6．19％,最大承载力增加了21．66％,极限强度增加了16．93％,结论：应用补肾益精方可以明显改善去卵巢大鼠骨质疏松模型松质骨的生物力学性能。     

"Ultrasound comet-tail images": a marker of pulmonary edema: a comparative study with wedge pressure and extravascular lung water

BACKGROUND: Echographic examination of the lung surface may reveal multiple "comet-tail images" originating from water-thickened interlobular septa. These images could be useful for noninvasive assessment of interstitial pulmonary edema. STUDY OBJECTIVE: The purpose of this study was to assess the diagnostic accuracy of lung comet-tail images compared with chest radiography, wedge pressure, and extravascular lung water (EVLW) quantified by the indicator dilution method (PiCCO System, version 4.1; Pulsion Medical Systems; Munich, Germany). METHODS AND PATIENTS: We enrolled 20 patients (mean age, 62.6 +/- 11.5 years [+/- SD]). Patients were studied before, immediately after, and 24 h following cardiac surgery with chest ultrasound, chest radiography, pulmonary artery catheterization, and the PiCCO system. Performing echo scanning (right and left hemithorax, from second to fourth intercostal space, from parasternal to midaxillary line), an individual patient comet score was obtained by summing the number of comets in each scanned space. RESULTS: A total of 60 comparisons were obtained. Significant positive linear correlations were found between comet score and EVLW determined by the PiCCO System (r = 0.42, p = 0.001), between comet score and wedge pressure (r = 0.48, p = 0.01), and between comet score and radiologic lung water score (r = 0.60, p = 0.0001). CONCLUSIONS: The presence and the number of comet-tail images provide reliable information on interstitial pulmonary edema. Therefore, ultrasonography represent an attractive, easy-to-use, bedside diagnostic tool for assessing cardiac function and pulmonary congestion.     

Echocardiographically detected mass "in transit" in early amniotic fluid embolism.

BACKGROUND: Amniotic fluid embolism is a catastrophic illness related to the passage of fetal material into the pulmonary circulation causing cardiovascular collapse. CASE: A 29-year-old female sustained cardiopulmonary arrest during delivery presumably due to amniotic fluid embolism. A right atrial mass "in transit" was detected by echocardiography. It had an appearance and pattern of motion that was suggestive of a gelatinous consistency and is likely to have been an amniotic fluid embolus. There was also evidence of acute right ventricular overload. CONCLUSION: We recommend that echocardiography be considered early on such conditions to gain more insight into the pathogenesis of this complication.     

哺乳动物心脏微血管形态学研究——Ⅱ.急性心肌梗塞“侧边带”的微血管

结扎家兔左冠状动脉左室支制作急性心肌梗塞的动物模型,用墨汁灌注和双色素灌注制作透明标本,发现心肌梗塞后24小时梗塞区域和未受累区域傲血管相邻排列的部位暴露出边界整齐的微血管,而对峙排列的部位暴露出参差不齐的终末毛细血管管袢,毛细血管的密度明显减少。同时,出现微血管的盲端,局部扩张及渗出等改变,可能这就是缺血的“侧边带”。     

青海"三江源"地区鼠疫血清流行病学调查分析

目的对青海省"三江源"地区开展鼠疫血清流行病学调查,了解分析流行态势,为该地区鼠疫防治措施的制定与落实提供依据。方法对历年的鼠疫细菌学资料进行总结分析,对"三江源"部分地区人及各种动物采血做血清抗体调查。结果该地区发现15种动物可自然感染鼠疫,10种动物血清存在鼠疫抗体,人群血清鼠疫抗体阳性率达2.47%。结论"三江源"地区动物鼠疫持续流行,参与染疫的动物种类多,时常波及人间造成人间鼠疫流行,人群存在部分隐性感染鼠疫者。尚有部分地区需进行深入的自然疫源地调查。     

“小粘膜”型胃癌诊断的探讨

所谓“小粘膜”型胃癌系指病灶直径小于４ｃｍ,局限于粘膜层或仅有轻度粘膜下层侵犯的早期胃癌。本文总结经内镜发现并得到手术、病理证实的“小粘膜”型胃癌１２例,着重对期诊断问题作一探讨。