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Marker Tests (marker + test)
Selected AbstractsDisseminated intravascular coagulation in acute leukemia: clinical and laboratory features at presentationEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 4 2006Masamitsu Yanada Abstract:,Background:,Although there are two major scoring systems for the clinical diagnosis of disseminated intravascular coagulation (DIC), the validity of these systems for leukemia-associated DIC remains to be confirmed. Methods:,By analyzing 125 newly diagnosed acute leukemia patients, we investigated clinical and laboratory features of leukemia-associated DIC, and determined the validity of the two established criteria. Results:,A total of 36 patients (29%) were diagnosed with DIC according to expert opinion, a method regarded as the de facto gold standard. Leukemia-associated DIC is characterized by rare manifestation of organ failure because of thrombosis and no relevance of the platelet count for the diagnosis. The results of receiver operating characteristics analysis favored fibrin degradation product (FDP) rather than D-dimer as the fibrin-related marker test. Although prothrombin time, plasma fibrinogen, and serum FDP levels were significantly different for patients with and without DIC, multivariate analysis identified FDP levels to be the only factor associated with DIC diagnosis. The cut-off level of 15 ,g/mL for FDP was found to be the most effective to differentiate DIC from non-DIC, resulting in diagnostic sensitivity and specificity of 92% and 96%, respectively. The diagnostic results for our patients produced with this FDP-based system were at least comparable with or superior to those obtained with the two currently available scoring systems. Conclusions:,Our findings suggest that an FDP-based criterion may be applicable for the diagnosis of leukemia-associated DIC. Although it appears to be simple and practicable enough for clinical use, prospective validation of this criterion is needed. [source] Fine mapping a quantitative trait locus on horse chromosome 2 associated with radiological signs of navicular disease in Hanoverian warmblood horsesANIMAL GENETICS, Issue 6 2009M. S. Lopes Summary Navicular disease or podotrochlosis is one of the main causes of progressive forelimb lameness in warmblood horses. The objective of this study was to refine a quantitative trait locus on horse chromosome 2 for radiological alterations in the contour of the navicular bone (RAC) in Hanoverian warmblood horses. Genotyping was performed in 192 Hanoverian warmblood horses from 17 paternal half-sib groups. The marker set was extended to 58 informative microsatellites including nine newly developed microsatellites. QTL for RAC could be delineated at 32.50,43.13 Mb and a further new QTL for RAC could be identified at 59.08,65.14 Mb. The markers ABGe342 and ABGe343 reached the highest multipoint Zmean and LOD scores at 34.42 and 35.23 Mb with genome-wide error probabilities of P = 0.013 and P = 0.064. In addition, significant associations of markers and haplotypes within the QTL could be shown. The results support the location of the QTL on ECA2 associated with RAC. This work is a further step towards the development of a marker test for navicular disease in Hanoverian warmblood horses. [source] Urinary biomarker profiling in transitional cell carcinomaINTERNATIONAL JOURNAL OF CANCER, Issue 11 2006Nicholas P. Munro Abstract Urinary biomarkers or profiles that allow noninvasive detection of recurrent transitional cell carcinoma (TCC) of the bladder are urgently needed. We obtained duplicate proteomic (SELDI) profiles from 227 subjects (118 TCC, 77 healthy controls and 32 controls with benign urological conditions) and used linear mixed effects models to identify peaks that are differentially expressed between TCC and controls and within TCC subgroups. A Random Forest classifier was trained on 130 profiles to develop an algorithm to predict the presence of TCC in a randomly selected initial test set (n = 54) and an independent validation set (n = 43) several months later. Twenty two peaks were differentially expressed between all TCC and controls (p < 10,7). However potential confounding effects of age, sex and analytical run were identified. In an age-matched sub-set, 23 peaks were differentially expressed between TCC and combined benign and healthy controls at the 0.005 significance level. Using the Random Forest classifier, TCC was predicted with 71.7% sensitivity and 62.5% specificity in the initial set and with 78.3% sensitivity and 65.0% specificity in the validation set after 6 months, compared with controls. Several peaks of importance were also identified in the linear mixed effects model. We conclude that SELDI profiling of urine samples can identify patients with TCC with comparable sensitivities and specificities to current tumor marker tests. This is the first time that reproducibility has been demonstrated on an independent test set analyzed several months later. Identification of the relevant peaks may facilitate multiplex marker assay development for detection of recurrent disease. © 2006 Wiley-Liss, Inc. [source] Role of second trimester sonography in detecting trisomy 18: A review of 70 casesJOURNAL OF CLINICAL ULTRASOUND, Issue 2 2007Csaba Papp MD Abstract Purpose. To investigate the role of second-trimester sonographic examination in the prenatal diagnosis of trisomy 18. Methods. Out of 22,150 fetal chromosomal analyses performed between 1990 and 2004, 70 trisomy 18 fetuses were found. The sonographic findings of this aneuploidy were analyzed. Results. The average maternal age was 32.4 years; the average gestational age was 19.5 weeks. Major anomalies were seen in 61 (87.1%) of the 70 fetuses with trisomy 18; among these, cardiac anomalies were the most common (47.1%), with a 27.1% incidence of ventricular septal defects. Anomalies of the central nervous system were seen in 35.7% of cases; abnormal head shape was the most frequently detected anomaly in this group (12.9%). Fifty-six (80%) of the fetuses had at least 1 minor anomaly; of these, choroid plexus cyst was the most common (38.6%). Increased nuchal fold thickness was detected in 17.1% of cases. Conclusion. The vast majority of trisomy 18 fetuses have sonographically detectable abnormalities in the second trimester. Both the 87.1% frequency of major anomalies and the 80% frequency of minor anomalies are substantially higher than multiple biochemical marker tests could achieve. It was also demonstrated that fetal echocardiography plays a pivotal role in the diagnosis of trisomy 18. © 2006 Wiley Periodicals, Inc. J Clin Ultrasound 35:, 2007 [source] U-Statistics-based Tests for Multiple Genes in Genetic Association StudiesANNALS OF HUMAN GENETICS, Issue 6 2008Zhi Wei Summary As our understanding of biological pathways and the genes that regulate these pathways increases, consideration of these biological pathways has become an increasingly important part of genetic and molecular epidemiology. Pathway-based genetic association studies often involve genotyping of variants in genes acting in certain biological pathways. Such pathway-based genetic association studies can potentially capture the highly heterogeneous nature of many complex traits, with multiple causative loci and multiple alleles at some of the causative loci. In this paper, we develop two nonparametric test statistics that consider simultaneously the effects of multiple markers. Our approach, which is based on data-adaptive U-statistics, can handle both qualitative data such as case-control data and quantitative continuous phenotype data. Simulations demonstrate that our proposed methods are more powerful than standard methods, especially when there are multiple risk loci each with small genetic effects. When the number of disease-predisposing genes is small, the data-adaptive weighting of the U-statistics over all the markers produces similar power to commonly used single marker tests. We further illustrate the potential merits of our proposed tests in the analysis of a data set from a pathway-based candidate gene association study of breast cancer and hormone metabolism pathways. Finally, potential applications of the proposed tests to genome-wide association studies are also discussed. [source] Testicular carcinoma and HLA Class II genesCANCER, Issue 9 2002Dirk J. A. Sonneveld M.D., Ph.D. Abstract BACKGROUND The association with histocompatibility antigens (HLA), in particular Class II genes (DQB1, DRB1), has recently been suggested to be one of the genetic factors involved in testicular germ cell tumor (TGCT) development. The current study, which uses genotyping of microsatellite markers, was designed to replicate previous associations. METHODS In 151 patients, along with controls comprising parents or spouses, the HLA region (particularly Class II) on chromosome 6p21 was genotyped for a set of 15 closely linked microsatellite markers. RESULTS In both patients and controls, strong linkage disequilibrium was observed in the genotyped region, indicating that similar haplotypes are likely to be identical by descent. However, association analysis and the transmission disequilibrium test did not show significant results. Haplotype sharing statistics, a haplotype method that derives extra information from phase and single marker tests, did not show differences in haplotype sharing between patients and controls. CONCLUSION The current genotyping study did not confirm the previously reported association between HLA Class II genes and TGCT. As the HLA alleles for which associations were reported are also prevalent in the Dutch populations, these associations are likely to be nonexistent or much weaker than previously reported. Cancer 2002;95:1857,63. © 2002 American Cancer Society. DOI 10.1002/cncr.10903 [source] | |||||||||||||