Use of the ambulatory ECG to diagnose coronary artery disease

Forty-nine patients undergoing cardiac catheterization for suspected coronary artery disease (CAD) were monitored with a two-channel ambulatory ECG and were given maximal treadmill exercise tests when these were not contraindicated. The ambulatory ECG recordings were evaluated for the number of ST segment deviations after correction for positional changes, and the results were then compared with those of the exercise test and coronary angiography. Sensitivity and specificity of ambulatory ECG monitoring for ST segment deviations to detect CAD were 76% and 75% respectively while those of exercise testing were 78% and 63% respectively. Sixteen patients (33% of this series) had equivocal or contraindicated exercise tests and twelve of these patients were correctly classified as to the presence or absence of CAD by ambulatory ECG. ST segment deviations on ambulatory ECG were found in 93% of patients with three vessel, two vessel, or one vessel LAD disease, while exercise testing detected 74% of these patients. Ambulatory ECG is an effective non-invasive method to diagnose CAD and is complementary to exercise testing. It is of special value when the exercise test is equivocal or contraindicated.     

急性胰腺炎胰外并发症的CT表现

目的 探讨急性胰腺炎（AP）胰外并发症的CT征象对判断AP严重程度的价值。方法 收集89例AP患者的临床资料和CT片，分析AP时胰腺外组织或器官并发症的发生率及CT征象。结果 89例AP中30例（33．7％）CT扫描仅见胰周组织坏死，59例（66．3％）显示胰外并发症，其中6例（6．7％）出现腹腔血管并发症，包括5例腹腔积血和1例胰周动脉瘤；1例（1．1％）并发肝脓肿；52例（58．4％）显示腹水，其中合并胸水29例（32．6％），心包积液2例（2．2％），肺底局限性片状炎症渗出7例（7．9％）；15例（16．9％）并发肺水肿，其中11例（12．4％）进展为成人呼吸窘迫综合征（ARDS）后死亡。结论 AP时腹部血管破裂或栓塞、胸腹水及肺部ARDS是严重的并发症，这些并发症的CT征象是判断AP严重程度的重要指标。     

Mast cells are critical mediators of vaccine-induced Helicobacter clearance in the mouse model

BACKGROUND & AIMS: Despite the proven ability of immunization to prevent Helicobacter infection in mouse models, the precise mechanism of protection has remained elusive. METHODS: We explored the cellular events associated with Helicobacter clearance from the stomach following vaccination by flow cytometry analysis and histological and molecular studies. RESULTS: Kinetic studies showed that the infection is undetectable in vaccinated mice at day 5 postbacterial challenge. Flow cytometry analysis showed that the percentages of mast cells (CD3 - CD117 + ) increased in the lymphoid cells isolated from the stomach at day 4 postchallenge in urease + cholera toxin (CT)-vaccinated mice in comparison with mice administered with CT alone (9.4% +/- 4.4% and 3.1% +/- 1%, respectively, for vaccinated and CT administered, n = 5; P < .01). Quantitative PCR analysis showed an increased messenger RNA (mRNA) expression of the mast cell proteases 1 and 2 at day 5 postchallenge in the stomach of vaccinated mice. In contrast to wild-type mice, mast cell-deficient mice (W/W v mice) were not protected from H felis colonization after vaccination. Indeed only 1 out of 12 vaccinated W/W v mice showed a negative urease test. Remarkably, vaccinated W/W v mice reconstituted with cultured bone marrow-derived mast cells recovered the ability to clear the infection after vaccination (8 out of 10 mast cell-reconstituted mice showed negative urease tests [ P < .006 as compared with wild-type mice]). CONCLUSIONS: These experiments show that mast cells are, unexpectedly, critical mediators of anti- Helicobacter vaccination.     

Real-Time Cardiac Catheter Navigation on Three-Dimensional CT Images

Introduction: Targets for ablation of atrial fibrillation, atrial flutter, and non-idiopathic ventricular tachycardia are increasingly being selected based on anatomic considerations. Because fluoroscopy provides only limited information about the relationship between catheter positions and cardiac structures, and is associated with radiation risk, other approaches to mapping may be beneficial. Methods: The spatial and temporal information of an electromagnetic catheter tip position sensing system (Magellan, Biosense Inc.) was superimposed on a three-dimensional (3D) CT of the chest in swine using fiducial markers for image registration. Position and orientation of a 6 French catheter with an electromagnetic sensor was displayed in real-time on a corresponding 3D-CT. Catheter navigation within the heart and the great vessels was guided by detailed knowledge about catheter location in relation to cardiac anatomy. Results: Anatomic structures including the atrial septum, pulmonary veins, and valvular apparatus were easily identified and used to direct catheter navigation. During the right heart examination, the catheter was navigated through the superior and inferior vena cava to predetermined anatomic locations in right atrium, right ventricle and pulmonary artery. The ablation catheter was also navigated successfully from the aorta through the aortic valve in the left ventricle. No complication was encountered during the experiments. The accuracy and precision of this novel approach to mapping was 4.69 ± 1.70 mm and 2.22 ± 0.69 mm, respectively. Conclusions: Real-time display of catheter position and orientation on 3D-CT scans allows accurate and precise catheter navigation in the heart. The detailed anatomic information may improve anatomically based procedures like pulmonary vein ablation and has the potential to decrease radiation times.     

Safety,reliability, and operability of cochlear implant electrode arrays coated with biocompatible polymer

Conclusion: Polymer-coated electrodes can reduce surgically-induced trauma associated with the insertion of a cochlear implant (CI) electrode array. Objectives: To evaluate if insertion trauma in CI surgery can be reduced by using electrode arrays coated with 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer. Methods: We analyzed characteristics of the Contour Advance® electrode arrays coated with MPC polymer. To assess surgical trauma during electrode insertion, polymer-coated or uncoated (n = 5 each) animal electrode arrays were implanted in guinea pig cochleae and operability and electrophysiological and histological changes were assessed. Results: Under light and scanning electron microscopy, polymer-coated electrodes did not appear different from uncoated electrodes, and no change was observed after mechanical stressing of the arrays. Electrode insertion was significantly easier when polymer-coated electrodes were used. Auditory brainstem response (ABR) thresholds did not differ between groups, but p1-n1 amplitudes of the coated group were larger compared with the uncoated group at 32 kHz at 28 days after surgery. The survival of outer hair cells and spiral ganglion cells was significantly greater in the polymer-coated group.     

128层螺旋CT对肠梗阻的诊断价值

目的：探讨多层螺旋CT（muhislicse computed tomography,MSCT）在肠梗阻诊断中的应用价值。方法：对48例经128层MSCT检查诊断为肠梗阻的病例进行回顾性分析。结果：48例患者MSCT诊断结果均与术后病理结果或临床随访结果相符合,48例肠梗阻中,粘连21例,肿瘤6例,肠套叠5例,嵌顿疝4例,先天性巨结肠1例,麻痹性3例,粪石2例,肠扭转6例,CT对急性肠梗阻病因诊断符合率为91.66%（44/48）。结论：128层MSCT检查能显著提高肠梗阻存在与否、对梗阻病因、有无绞窄诊断准确率高,对诊断急性肠梗阻有很高的价值。     

特发性肺纤维化的CT征象分析及其临床意义

目的：探讨特发性肺纤维化（IPF）的cT表现特征及其临床意义。方法：回顾性分析25例IPF患者的CT表现及复习文献资料,总结其特征。结果：25例IPF患者的CT表现复杂多样,磨玻璃样高密度灶1例,网格状变25例,蜂窝状变22例,支气管及细支气管牵拉性扩张23例,界面征20例,胸膜下线16例,支气管血管束增粗12例,纵隔淋巴结肿大14例,胸膜增厚15例,肺动脉高压8例,肺大泡5例。病变以网格状、蜂窝状变为主,主要位于肺基底部及肺外围,且病变由肺尖到肺底逐渐增多,由肺外围到肺门侧逐渐减轻。结论：IPF的CT征象及其分布具有特征性,结合临床可作出明确诊断。     

CT 联合超声对于甲状腺乳头状癌和腺瘤的影像表现探讨

目的：探讨 CT 联合超声对于甲状腺乳头状癌（PTC）和腺瘤（FAN）进行临床诊断及鉴别诊断的临床意义。方法：选取经术后病理证实诊断的45例,共53枚甲状腺病变的 CT 和超声资料,分别观察并对比超声及 CT 典型征象和超声联合 CT 典型征象在乳头状甲状腺癌诊断中的敏感性和特异性。结果：超声典型征象的敏感性为72.73%,特异性为54.76%;CT 典型征象的敏感性为63.64%,特异性为83.33%;超声联合 CT 典型征象的敏感性为90.91%,特异性为61.90%。结论：超声在诊断乳头状甲状腺癌中有较高的敏感性,而 CT 在诊断乳头状甲状腺癌中有较高的特异性,两者联合应用可以显著增高乳头状甲状腺癌诊断的敏感性,同时特殊的 CT 征象有助于乳头状甲状腺癌诊断。     

肺血容积效应合并肺挫裂伤的 CT 诊断分 析简

目的：探讨肺血容积效应合并肺挫裂伤的CT表现。方法：对46例胸部外伤仰卧位平扫见肺部背侧高密度影患者,再行侧卧位或俯卧位扫描,分析肺血容积效应合并肺挫裂伤的CT特征。结果：46例肺血容积效应患者中仰卧位发现12例合并肺挫裂伤,侧、俯卧扫描患者中发现26例合并肺挫裂伤,差异具有统计学意义（P＆lt;0.05）。结论：侧、俯卧位扫描在肺血容积效应合并肺挫裂伤中有诊断意义,避免误诊和漏诊。