AIDS-related cholangitis: radiographic findings in nine patients

Acalculous inflammation of the biliary tract is a recently reported complication of the acquired immunodeficiency syndrome (AIDS). In a 33-month period, nine men with AIDS were evaluated because of right upper quadrant and/or epigastric pain, jaundice, or abnormal liver function test results. Each patient underwent ultrasonography and endoscopic retrograde cholangiopancreatography; seven also underwent computed tomography. In eight of nine patients the imaging studies disclosed intrahepatic and extrahepatic bile duct changes identical to those seen in sclerosing cholangitis (strictures, focal dilatation, thickened duct walls). Isolated papillary stenosis and ductal dilatation were present in one patient, while eight patients had some stricturing of the distal common duct. The combination of papillary stenosis and intrahepatic ductal strictures appears unique to AIDS-related cholangitis. Endoscopic papillotomy provided variable relief to symptoms and biochemical abnormalities. Cholangitis caused by cytomegalovirus and/or Cryptosporidium infection is the proposed pathophysiologic mechanism.     

Differences in the subcomponents of fat-free body in relation to height between black and white children

The individual subcomponents of fat-free body (FFB) in relation to height were investigated in 131 white (N = 85) and black (N = 46) males (MW, MB) and 108 white (N = 63) and black (N = 45) females (FW, FB), aged 8 to 18 years. Bone mineral content (BM), bone width (BW), and bone mineral index (BMI) were measured using photon absorptiometry; total body water (TBW) was measured by deuterium dilution; body density was measured by hydrostatic weighing, correcting for residual lung volume; and estimates of lean body mass (LBM) were made from total body potassium (⁴⁰K spectroscopy). The subcomponents of the FFB—BM, BW, BMI, TBW, and K—were regressed on the log of height to determine the exponent of the independent variable (Ht) that would most accurately predict the dependent variables (BM, BW, BMI, TBW, K) within gender and race. Regression equations were derived for each of the variables used to represent a subcomponent of the FFB on Ht. Significant (P < .05) racial differences were found in BW, with the MB having wider bones than the MW. Significant racial differences were observed in BMI with FB demonstrating a greater difference across height than FW. Racial differences in BM and TBW approached significance within the female sample. At heights greater than the mean of a typical pubescent child, the males had higher values for each of the variables, except for BMI, than did the females. The lower BMI values observed in males indicated that the rate at which male bones grow in width was greater than their rate of mineralization. Within the male sample, blacks had higher bone mineral than whites with the magnitude of these differences dependent on the variable under consideration. Within the female sample the blacks had greater amounts of BM and BMI in relation to height, while the whites had a greater amount of K. Therefore, the magnitude of the differences between blacks and whites in the subcomponents of the FFB are dependent on gender, stature, and the particular subcomponent of the FFB under consideration.     

MR imaging in chronic rupture of the ulnar collateral ligament of the thumb

Purpose: MR imaging has been shown as the best radiologic method for verifying and classifying acute ulnar collateral ligament (UCL) ruptures of the thumb. Our aim was to analyse the usefulness of MR also in old ruptures and to establish the most useful sequences.Material and Methods: Ten patients with an old UCL rupture of the thumb were preoperatively imaged using 1.5 T MR. Three radiologists blinded to the findings separately analysed the MR images of these patients and of 10 age-and sex-matched voluntary controls. MR findings of the patients were compared with those of surgery.Results: The consensus diagnosis of an UCL rupture was accurate in all 10 patients. All controls were classified as having no UCL rupture. In 5 of the 7 patients with a surgically defined Stener or non-Stener lesion, the consensus diagnosis was the same as the operative diagnosis. Due to excessive scarring it was not possible to verify any Stener lesion intra-operatively in 3 patients. The most informative MR sequence was T2 TSE in the coronal plane, the second most informative was T1 SE with fat suppression in the coronal plane.Conclusion: An old UCL rupture is well verified by MR but typing of the lesion as either a Stener or non-Stener type is not always possible.     

Total and regional fat and serum cardiovascular disease risk factors in lean and obese children and adolescents

OBJECTIVE: This study was conducted to evaluate the association of total and central adiposity with serum cardiovascular disease (CVD) risk factors in lean and obese Portuguese children and adolescents. RESEARCH METHODS AND PROCEDURES: A total of 87 girls (13.2 +/- 1.6 years old, 29.9 +/- 6.4% body fat [mean +/- SD]) and 72 boys (13.2 +/- 1.6 years old, 20.8 +/- 9.9% body fat) volunteered for the study. Whole-body composition and fat distribution, from DXA and anthropometry, and serum lipids, lipoproteins, and apolipoproteins were evaluated. RESULTS: The sum of three trunk skinfolds (STS) was highly correlated with total trunk fat mass measured by DXA (p < 0.001). Body mass index, DXA-measured percentage of body fat, trunk fat mass, STS, and the waist-to-height ratio were generally found to be associated with triacylglycerol, the ratio of total cholesterol (TC) to high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), and apolipoprotein B levels, (significant age-adjusted r between 0.16 and 0.27, p < 0.05). Body mass index, STS, and the waist circumference were also associated with HDL-C (p < 0.05), whereas no body composition variable significantly correlated with TC or apolipoproteins A-I. The STS was significantly correlated with HDL-C (p < 0.01), TC/HDL-C (p < 0.05), and apolipoproteins A-I (p < 0.05) independently of whole-body fatness. Obese subjects (n = 73) had higher TC, LDL-C, TC/HDL-C, and apolipoprotein B than did non-obese subjects (n = 86), and significant associations between central adiposity and some lipid variables (triacylglycerol and HDL-C) were found in obese children and adolescents that were not present in leaner individuals. DISCUSSION: DXA- and anthropometry-based whole-body and central fat measures are associated with serum CVD risk factors in Portuguese boys and girls. Obese children and adolescents have a poorer lipid profile than do their leaner counterparts. Trunk skinfolds, which are easy to obtain even in large samples, predict CVD risk factors to the same extent as DXA-based variables, in some cases, independently of total fatness.     

Performance of weighted estimating equations for longitudinal binary data with drop-outs missing at random

The generalized estimating equations (GEE) approach is commonly used to model incomplete longitudinal binary data. When drop-outs are missing at random through dependence on observed responses (MAR), GEE may give biased parameter estimates in the model for the marginal means. A weighted estimating equations approach gives consistent estimation under MAR when the drop-out mechanism is correctly specified. In this approach, observations or person-visits are weighted inversely proportional to their probability of being observed. Using a simulation study, we compare the performance of unweighted and weighted GEE in models for time-specific means of a repeated binary response with MAR drop-outs. Weighted GEE resulted in smaller finite sample bias than GEE. However, when the drop-out model was misspecified, weighted GEE sometimes performed worse than GEE. Weighted GEE with observation-level weights gave more efficient estimates than a weighted GEE procedure with cluster-level weights.     

EWING'S SARCOMA OF MANDIBLE – A RARE NEOPLASM

Ewing''s sarcoma is a highly malignant tumour seen in the age group of 5 to 25 years, primarily afflicts long bones of the extremities followed by pelvis, ribs and vertebrae. The involvement of this lesion in the mandible accounts for only 2% of the reported cases. Ewing''s sarcoma particularly in children, poses difficulty in arriving at a diagnosis and could be established only by histopathological and electron microscopic examination. This is a radiosensitive lesion, however, surgery with chemotherapy is the preferred treatment of choice in mandible. A case of Ewing''s sarcoma in a 7 year old female patient was managed by chemotherapy and aggressive surgical approach with gratifying results and no recurrence till date.KEY WORDS: Chemotherapy, Cytogenetic studies, Ewing''s sarcoma, Hemimandibulectomy, Immunohistochemistry     

利用T_1加权DCE-MRI技术对脑胶质瘤分级

应用T1加权动态对比度增强磁共振成像(DCE-MRI)技术对脑胶质瘤进行术前分级,验证其用于脑胶质瘤分级的准确性和可重复性。对26例脑胶质瘤患者团注Gd-DTPA对比剂后,以1.5TSiemens Syngo MRI扫描仪采集DCE T1加权图像。首先基于改进的Tofts两室药物动力学模型,从采集到的动态组图像建立病灶区感兴趣区内的平均信号强度-时间曲线,然后应用非线性最小二乘拟合方法对该曲线进行拟合,获取定量参数。这些参数包括:初始增强率ER、回流速率常数Kep、排泄速率常数Kel、曲线下面积AUC、峰值高度PH、到达峰值的时间TTP,最后与临床组织病理学结果进行比较,建立这些定量参数与脑胶质瘤分级之间的定量关系。采用独立样本t检验比较任意两个分级之间各定量参数的统计学差异,P0.05作为统计学差异标准。ER、AUC和PH随着脑胶质瘤的病理分级由低到高地增加;低级别脑胶质瘤中的Ⅰ与Ⅱ级之间以及高级别中的Ⅲ与Ⅳ级之间的比较结果显示,ER、AUC和PH的值均无明显统计学差异(P0.05);低级别与高级别级之间的比较结果显示,仅参数ER的差异具有统计学意义(P0.05)。ER是术前准确界定脑胶质瘤低级别与高级别的最具敏感性和特异性的参数,其界定阈值约为0.68。