US-guided percutaneous biopsy: use of a screw biopsy stylet to aid needle detection

Insertion of a screw biopsy stylet into a thin-walled biopsy needle greatly enhances detection of the needle during ultrasound-guided percutaneous biopsy. This technique is helpful when precise needle-tip localization is needed for biopsies of small lesions.     

Pulmonary cystic disease: comparison of Pneumocystis carinii pneumatoceles and bullous emphysema due to intravenous drug abuse

A rare pulmonary manifestation of the acquired immunodeficiency syndrome or intravenous (IV) drug abuse is upper lobe cystic disease--pneumatoceles in Pneumocystis carinii pneumonia (PCP) and bullous emphysema in IV drug abuse. Because these disorders overlap, the radiographic findings in 56 patients were compared. During a 12-month period, 16 patients less than 40 years of age were found to have bullous emphysema; the 10 who were IV drug abusers constituted group 1. In the same time period, 40 patients with PCP were encountered; the eight (20%) who had or developed pneumatoceles constituted group 2. In both groups, the conventional radiographic manifestations of upper lobe cystic disease were similar. Eight patients underwent computed tomography of the chest. In five patients with bullous disease, the distribution of the bullous lesions was peripheral, with sparing of the central portions of the lungs. In contrast, PCP pneumatoceles in three patients were dispersed throughout the lung parenchyma.     

Methods to monitor response to chemotherapy in non-small cell lung cancer with 18F-FDG PET.

PET using 18F-FDG is a promising technique to monitor response in oncology. Unfortunately, a multitude of analytic methods is in use. To date, it is not clear whether simplified methods could replace complex quantitative methods in routine clinical practice. The aim of this study was to select those methods that would qualify for further assessment in a future prospective response-monitoring study by comparing results with patient outcome. METHODS: Dynamic 18F-FDG PET scans were obtained on 2 groups of patients. First, 10 patients with advanced non-small cell lung cancer (NSCLC) were scanned on consecutive days before treatment to assess test-retest variability. Second, 30 scans were obtained on 19 patients with locally advanced NSCLC as part of an ongoing response-monitoring study. These scans were analyzed by 2 observers to assess observer variability. In addition, these studies were used to compare various methods with the gold standard, full kinetic analysis (nonlinear regression [NLR]). RESULTS: Using an image-derived input function, NLR showed excellent test-retest and observer agreement confirming that it could be used as a gold standard method. From a total of 34 analytic methods, 10 showed good correlation with NLR. Taking into account the degree of complexity of the methods, 4 remain for further evaluation. CONCLUSION: The optimal method for analysis of 18F-FDG PET data was determined for several levels of complexity. Four methods need to be evaluated further to determine the optimal trade-off between simplicity and accuracy for routine clinical practice.     

The role of the LDL receptor in apolipoprotein B secretion

Familial hypercholesterolemia is caused by mutations in the LDL receptor gene (Ldlr). Elevated plasma LDL levels result from slower LDL catabolism and a paradoxical lipoprotein overproduction. We explored the relationship between the presence of the LDL receptor and lipoprotein secretion in hepatocytes from both wild-type and LDL receptor-deficient mice. Ldlr(-/-) hepatocytes secreted apoB100 at a 3.5-fold higher rate than did wild-type hepatocytes. ApoB mRNA abundance, initial apoB synthetic rate, and abundance of the microsomal triglyceride transfer protein 97-kDa subunit did not differ between wild-type and Ldlr(-/-) cells. Pulse-chase analysis and multicompartmental modeling revealed that in wild-type hepatocytes, approximately 55% of newly synthesized apoB100 was degraded. However, in Ldlr(-/-) cells, less than 20% of apoB was degraded. In wild-type hepatocytes, approximately equal amounts of LDL receptor-dependent apoB100 degradation occured via reuptake and presecretory mechanisms. Adenovirus-mediated overexpression of the LDL receptor in Ldlr(-/-) cells resulted in degradation of approximately 90% of newly synthesized apoB100. These studies show that the LDL receptor alters the proportion of apoB that escapes co- or post-translational presecretory degradation and mediates the reuptake of newly secreted apoB-containing lipoprotein particles.     

Standardizing the definition of hyperenhancement in the quantitative assessment of infarct size and myocardial viability using delayed contrast-enhanced CMR.

PURPOSE: To evaluate a standardized definition of delayed hyperenhancement in the analysis of contrast-enhanced cardiac magnetic resonance (ceCMR) imaging. PATIENTS AND METHODS: CeCMR was performed in 15 patients with chronic ischemic heart disease. Delayed hyperenhancement was analyzed both by visual analysis by an experienced team of observers, and after thresholding the window setting of the images at 2, 3, 4, 5, and 6 SD above the mean signal intensity of remote, normal myocardium in the same slice. In each patient, total infarct size (TIS) and segmental infarct extent (SIE) were calculated. RESULTS: TIS and SIE were 22.9 +/- 12.2 mL and 32 +/- 28% after visual analysis. Thresholding the window setting at 2, 3, 4, and 6 SD above signal intensity of remote caused a 40%, 31%, and 17% increase (p < 0.007) and a 7% decrease (p = NS) in TIS, and a 75%, 41%, and 16% increase and 22% decrease in SIE (p < 0.001), respectively. There was no difference between visual analysis and analysis after thresholding at 5 SD. CONCLUSION: Analyzing ceCMR with a standardized definition of hyperenhancement related to the signal of remote, nonenhanced myocardium may result in considerable overestimation of infarct size at the usual cut-off of 2 SD.     

体外膜肺氧合技术支持治疗期间患者血乳酸浓度及其预后

目的:探讨体外膜肺氧合支持治疗患者血乳酸浓度的变化和预后。方法:于2004-12/2006-09在中国医学科学院阜外心血管病医院因脱离体外循环困难的心脏外科术后患者、扩张性心肌病和冠状动脉粥样硬化性心脏病发生心源性休克的患者共40例进行了体外膜肺氧合支持治疗,按年龄和存活预后分为4组:成人存活组、成人死亡组、儿童存活组、儿童死亡组。分析4组的治疗效果,分别抽取各组患者体外膜肺氧合建立时、体外膜肺氧合运转6h、运转中间时点、停机前6h、停机时的血乳酸浓度。结果:①体外膜肺氧合支持治疗患者40例,成人组26例,20例脱机,16例生存,10例死亡,脱机率76.9%,生存率61.5%;儿童组14例,7例脱机,5例生存,9例死亡,脱机率50.0%,生存率35.0%。②成人或儿童存活组的乳酸浓度都与死亡组有明显差别,存活组血乳酸浓度明显低于死亡组,其中建立和运转6h、中间时点的差异有显著性意义(P<0.05),其余2个时点的差异有非常显著性意义(P<0.001)。组内与建立时比较,中间时点、停止前6h、停止时差异均有显著性意义(P<0.001),血乳酸浓度逐渐降低。结论:经体外膜肺氧合支持治疗的患者,血乳酸浓度明显下降,脱机时血乳酸仍高的患者预后不良。