Discriminative conditioning-related slow potential and single-unit responses in the frontal cortex of urethane-anesthetized rats

A model is described for obtaining long-term and stable discriminative conditioning-related slow-potential and single-unit responses from the frontal cortex of urethane-anesthetized rats. Responses were recorded and analyzed to reinforced (rewarding medial forebrain bundle stimulation) and non-reinforced tone cues. In the present study, cortical event-related slow potentials provided an adequate index of the level of discriminative conditioning. Single-unit response patterns are described for 57 neurons which demonstrated a discriminative response to either the reinforced or non-reinforced tone cue.     

内结扎法腹腔镜巨脾切除联合选择性贲门周围血管离断术

目的总结腹腔镜下内结扎法巨脾切除联合选择性贲门周围血管离断术的经验。方法采用丝线结扎结合超声刀或LigaSure，进行腹腔镜巨脾切除和选择性贲门周围血管离断术治疗门静脉高压症并发食管胃底静脉曲张6例。结果6例手术全部镜下顺利完成，术中出血量80-200ml，平均130ml，无输血，无中转开腹，手术时间150-210min平均190min。无并发症，术后5天恢复正常活动。术后随访3—10个月，平均8个月，无再发出血。结论应用内结扎法腹腔镜巨脾切除联合选择性贲门周围血管离断术治疗门静脉高压症安全有效，出血少，微创。     

国内关节镜下后交叉韧带重建术的现状与展望

后交叉韧带是维持膝关节稳定的重要结构,损伤后宜早期干预,才能减少并发症的发生并提高治疗效果。而关节镜下重建后交叉韧带是现有技术水平上最为理想的选择。本文就国内现有的应用较多的关节镜下后交叉韧带的重建术式、不同重建材料及重建固定技术进行总结和疗效比较。     

Neuroimaging and Neurologic Complications after Organ Transplantation

Neurologic complications are common after transplantation and affect 30-60% of transplant recipients. The etiology of most of the posttransplant neurologic disorders is related to the opportunistic infections, both systemic and involving central nervous system (CNS), toxicity of immunosuppressive medications, and the metabolic insult created by the underlying primary disease and the transplant procedure. Neuroimaging studies are one of the key tools in the evaluation and enable early diagnosis of neurologic complications in transplant patients, especially posterior reversible leukoencephalopathy syndrome, central pontine myelinolysis, intracerebral hemorrhage, and fungal and bacterial abscesses. Magnetic resonance imaging (MRI) is the preferred technique, but each of the available neuroimaging techniques offers a unique insight into the pathophysiologic mechanisms underlying neurologic complications of transplantation. The role of neuroimaging in this population includes early detection of calcineurin inhibitor neurotoxicity, opportunistic infections, neoplasia, metabolic disorders, or cerebrovascular diseases. In addition, we can monitor longitudinal progression of disease and treatment response.     

家兔颈后肌受长期应力作用的实验研究

目的 建立颈后肌受长期应力作用动物模型并进行相关研究.方法 30只家兔随机分为模型组和对照组,每组15只.模型组家兔置于特制低头位框架中,低头角度为45度,每天1次,每次5小时;对照组除不低头外余条件相同.12周后分别进行颈椎X线、颈后部红外热像图、血清肌酸激酶和乳酸脱氢酶含量以及颈后肌超氧化物歧化酶和丙二醛含量观察.结果 模型组颈椎X线改变积分值实验后明显高于实验前和对照组,差异具有显著性;模型组与对照组颈后部红外热像图有明显差异;模型组血清肌酸激酶、乳酸脱氢酶的含量均明显高于对照组;模型组丙二醛含量明显高于对照组而超氧化物歧化酶含量明显低于对照组.结论 家兔颈后肌受长期应力作用后出现颈部的生物力学和生物化学失衡.     

颈椎斜位片在下颈椎椎弓根螺钉术的研究

目的通过C形臂X线机以不同角度拍摄的尸体颈椎样本的斜位片观测颈椎椎弓根。在此基础之上不同角度的颈椎斜位片上观察术前拟行下颈椎椎弓根钉植入的患者颈椎椎弓根影象学表现。在这两个观测的基础上找到颈椎椎弓根及螺钉植入的最佳斜位片角度。方法选用干燥的人颈椎(C3~7)标本在C形臂X线机辅助下通过透视不同的斜位角度(40°、45°、50°、55°、60°)观测椎弓根。同时在颈椎标本观测的基础上,对拟行颈椎椎弓根螺钉植入患者术前摄不同角度的颈椎斜位片(45°、50°、55°)观测颈椎椎弓根的显示。两次试验都是观测椎弓根的长度及对侧椎弓根在椎体上显影的位置(把椎体3等分)。结果通过测量发现55°颈椎双斜位片对椎弓根长度的显示及对侧椎弓根位置显示与其他角度斜位片相比有明显的统计学差异(P<0.05)。结论55°双斜位片对术前颈椎椎弓根的判断及术中椎弓根钉植入准确性的判断是斜位片的最佳角度。     

Evaluation of left ventricular mechanical dyssynchrony as determined by phase analysis of ECG-gated SPECT myocardial perfusion imaging in patients with left ventricular dysfunction and conduction disturbances

Background  Cardiac resynchronization therapy (CRT) is approved for the treatment of patients with advanced systolic heart failure and evidence of dyssynchrony on electrocardiograms. However, a significant percentage of patients do not demonstrate improvement with CRT. Echocardiographic techniques have been used for more accurate determination of dyssynchrony. Single photon emission computed tomography (SPECT) myocardial perfusion imaging has not previously been used to evaluate cardiac dyssynchrony. The objective of this study is to evaluate mechanical dyssynchrony as described by phase analysis of gated SPECT images in patients with left ventricular dysfunction, conduction delays, and ventricular paced rhythms. Methods and Results  A novel count-based method is used to extract regional systolic wall thickening amplitude and phase from gated SPECT images. Five indices describing the phase dispersion of the onset of mechanical contraction are determined: peak phase, phase SD, bandwidth, skewness, and kurtosis. These indices were determined in consecutive patients with left ventricular dysfunction (n=120), left bundle branch block (n=33), right bundle branch block (n=19), and ventricular paced rhythms (n=23) and were compared with normal control subjects (n=157). Phase SD, bandwidth, skewness, and kurtosis were significantly different between patients with left ventricular dysfunction, left bundle branch block, right bundle branch block, and ventricular paced rhythms and normal control subjects (all P<.001) Peak phase was significantly different between patients with right ventricular paced rhythms and normal control subjects (P=.001). Conclusions  A novel SPECT technique for describing left ventricular mechanical dyssyn-chrony has been developed and may prove useful in the evaluation of patients for CRT. This study was funded in part by a research grant from the Medtronic-Duke Strategic Alliance, of which Dr Borges-Neto is the primary investigator.     

Myocardial perfusion SPECT reconstruction: Receiver operating characteristic comparison of CAD detection accuracy of filtered backprojection reconstruction with all of the clinical imaging information available to readers and solely stress slices iteratively reconstructed with combined compensation

BACKGROUND: Past receiver operating characteristic (ROC) studies have demonstrated that single photon emission computed tomography (SPECT) perfusion imaging by use of iterative reconstruction with combined compensation for attenuation, scatter, and detector response leads to higher area under the ROC curve (A(z)) values for detection of coronary artery disease (CAD) in comparison to the use of filtered backprojection (FBP) with no compensations. A new ROC study was conducted to investigate whether this improvement still holds for iterative reconstruction when observers have available all of the imaging information normally presented to clinical interpreters when reading FBP SPECT perfusion slices. METHODS AND RESULTS: A total of 87 patient studies including 50 patients referred for angiography and 37 patients with a lower than 5% likelihood for CAD were included in the ROC study. The images from the two methods were read by 4 cardiology fellows and 3 attending nuclear cardiologists. Presented for the FBP readings were the short-axis, horizontal long-axis, and vertical long-axis slices for both the stress and rest images; cine images of both the stress and rest projection data; cine images of selected cardiac-gated slices; the CEQUAL-generated stress and rest polar maps; and an indication of patient gender. This was compared with reading solely the iterative reconstructed stress slices with combined compensation for attenuation, scatter, and resolution. With A(z) as the criterion, a 2-way analysis of variance showed a significant improvement in detection accuracy for CAD for the 7 observers (P = .018) for iterative reconstruction with combined compensation (A(z) of 0.895 +/- 0.016) over FBP even with the additional imaging information provided to the observers when scoring the FBP slices (A(z) of 0.869 +/- 0.030). When the groups of 3 attending physicians or 4 cardiology fellows were compared separately, the iterative technique was not statistically significantly better; however, the A(z) for each of the 7 observers individually was larger for iterative reconstruction than for FBP. Compared with results from our previous studies, the additional imaging information did increase the diagnostic accuracy of FBP for CAD but not enough to undo the statistically significantly higher diagnostic accuracy of iterative reconstruction with combined compensation. CONCLUSIONS: We have determined through an ROC investigation that included two classes of observers (experienced attending physicians and cardiology fellows in training) that iterative reconstruction with combined compensation provides statistically significantly better detection accuracy (larger A(z)) for CAD than FBP reconstructions even when the FBP studies were read with all of the extra clinical nuclear imaging information normally available.     

湖北地区汉族变应性哮喘患儿Tim-3启动子区基因多态性研究

目的 探讨湖北地区汉族儿童T细胞免疫球蛋白黏蛋白域蛋白．3（Tim-3）启动子区1541位C〉T和574位G〉T单核苷酸变异及其与变应性哮喘易感性之间的关系。方法 分别采用聚合酶链反应．限制性片段长度多态性（PCR-RFLP）和引物特异PCR-核酸序列测定技术检测湖北143例哮喘患儿和72名健康儿童Tim-3启动子区1541位C〉T和574位G〉T单核苷酸变异，讣算基因型和等位基因频率。结果 湖北地区健康儿童Tim-3启动子区1541位C／C、C／T和T／T基因型频率分别是0．961、0．039和0，而哮喘患儿频率分别为0．935、0．065、0，其基因型频率与对照组差异无统计学意义（r=0．3825，P=0．5362）；湖北健康儿童中Tim-3启动子区574位G／G、G／T和T／T基因型频率分别为0．992、0．008和0，而哮喘患儿频率分别为0．941、0．059、0，两组基因型频率差异有统计学意义（χ^2=4．134，P=0．042）。结论 湖北汉族儿童Tim-3启动子区存在多态性变异，其中574位G〉T多态性可能与湖北汉族儿童变应性哮喘易感性有关。