Home About us Contact
|
Home About us Contact | ||
|
|
||
Detection Tests (detection + test)
Selected AbstractsThe consanguinity effect on QF-PCR diagnosis of autosomal anomaliesPRENATAL DIAGNOSIS, Issue 5 2006Michel B. Choueiri Abstract Objectives Quantitative Fluorescent PCR (QF-PCR) is a simpler and faster method of detecting common chromosomal abnormalities when compared to cytogenetic analysis. The aim of our study is to investigate the applicability of this methodology in a population where consanguineous marriages are common and to estimate the heterozygous frequency of the PCR markers used. Methods Four hundred and twenty-three DNA samples were extracted from uncultured amniocytes and amplified with 18 short tandem repeats (STR) markers specific to chromosomes 13, 18 and 21. Amplification products were analyzed using the GeneScan software. Results QF-PCR correctly identified all the numerical abnormalities related to chromosomes 13, 18 and 21. A total of 24 autosomal trisomies (5.7%) were detected. The markers D21S1432 and D21S11 were the most consistent in providing unequivocal positive results for chromosome 21 and the heterozygosity percentages of the markers used were lower than the values reported in Western populations. Conclusion QF-PCR is reliable for the prenatal diagnosis of numerical anomalies of the chromosomes 13, 18 and 21 in our study population. The absence of STR heterozygosity data from Lebanon and surrounding countries makes our study very useful for the development of a reliable QF-PCR trisomy detection test. Copyright © 2006 John Wiley & Sons, Ltd. [source] Usefulness of PCR Strategies For Early Diagnosis of Chagas' Disease Reactivation and Treatment Follow-Up in Heart TransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 6 2007M. Diez Heart transplantation (HTx) is a useful therapy for end-stage Chaga, cardiomyopathy; however, Chagas reactivation remains a mayor complication. Parasitological methods offer poor diagnostic sensitivity, and use of more sensitive tools such as the Polymerase chain reaction (PCR) is usually necessary. In the present study, reactivation incidence and PCR usefulness for early reactivation diagnosis, as well as for treatment response evaluation during follow-up, were analyzed using Strout parasite detection test, in 10 of 222 consecutive HTx patients suffering Chagas cardiomyopathy. PCR strategies targeted to minicircle sequences (kDNA, detection limit 1 parasite/ 10 mL blood) and miniexon genes (SL-DNA, 200 parasite/10 mL) were performed to compare parasite burdens between samples. No patients received prophylactic antiprotozoal therapy (benznidazole). Five patients (50%) exhibited clinical reactivation within a mean period of 71.6 days; positive Strout results were observed in most cases presenting clinical manifestations. kDNA-PCR was positive 38,85 days before reactivation, whereas SLDNA-PCR became positive only 7,21 days later, revealing post-HTx parasitic load enhancement present prior to clinical reactivation development. Reactivations were successfully treated with benznidazole and generated negative PCR results. Results observed in this study indicate the value of PCR testing for an early diagnosis of Chagas reactivation as well as for monitoring treatment efficacy. [source] Usefulness of Non-invasive Tests for Diagnosing Helicobacter pylori Infection in Patients Undergoing Dialysis for Chronic Renal FailureHELICOBACTER, Issue 6 2004Thaïs López ABSTRACT Background.,Helicobacter pylori infection in chronic renal failure patients has been linked to peptic ulcer and gastric neoplasia after kidney transplantation. It may also contribute to the accelerated arteriosclerosis that is usual in this population. Few data are available on the usefulness of noninvasive diagnostic tests for H. pylori infection in dialyzed patients, especially regarding the new fecal antigen detection tests. The objective of this study was to determine the efficacy of a noninvasive test for H. pylori infection in patients with chronic renal failure. Methods., Eighty-six patients were included in a cross-sectional study. Urea breath test, serology and three fecal tests , FemtoLab H. pylori (Connex, Germany), Premier Platinum HpSA (Meridian, USA) and Simple H. pylori (Operon SA, Spain) were performed. Helicobacter pylori status was determined by concordance of the tests. Sensitivity, specificity and positive and negative predictive values were calculated for each test. Results., Sensitivity, specificity, positive and negative predictive values were 94%, 96%, 94% and 96% for the urea breath test; 97%, 64%, 66% and 97% for serology; 86%, 100%, 100% and 91%, for FemtoLab H. pylori; 58%, 96%, 91% and 76% for Premier Platinum HpSA and 61%, 78%, 74% and 67% for Simple H. pylori. Conclusions., The urea breath test seems to be the most reliable diagnostic method for H. pylori infection in patients with chronic renal failure. Serology has a low specificity, and the results of the fecal tests vary widely. [source] A comparison of the presumptive luminol test for blood with four non-chemiluminescent forensic techniquesLUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 4 2006Joanne L. Webb Abstract Presumptive blood detection tests are used by forensic investigators to detect trace amounts of blood or to investigate suspicious stains. Through the years, a number of articles have been published on the popular techniques of the day. However, there is no single paper that critiques and compares the five most common presumptive blood detection tests currently in use: luminol, phenolphthalein (Kastle,Meyer), leucomalachite green, Hemastix® and the forensic light source. The present authors aimed to compare the above techniques with regard to their sensitivity, ease of use and safety. The luminol test was determined to be the most sensitive of the techniques, while Hemastix® is a suitable alternative when the luminol test is not appropriate. Copyright © 2006 John Wiley & Sons, Ltd. [source] Police officers ability to detect deception in high stakes situations and in repeated lie detection testsAPPLIED COGNITIVE PSYCHOLOGY, Issue 6 2006Aldert Vrij Thirty-seven police officers, not identified in previous research as belonging to groups that are superior in lie detection, attempted to detect truths and lies told by suspects during their videotaped police interviews. In order to measure consistency in their ability, the officers each participated in four different tests, each of which was on a different day. They were asked to indicate their confidence in being able to distinguish between truths and lies prior to the first test and after completing all four tests. We predicted that accuracy rates would be higher than those typically found in research with police officers; that good or poor performances on an individual test would be partly caused by luck, and, consequently, participants' accuracy scores were likely to progress towards the mean if their performance on all four tests was to be combined; and that officers would underestimate their own performance. These hypotheses were supported. Copyright © 2006 John Wiley & Sons, Ltd. [source] Geographic distribution of autism in California: A retrospective birth cohort analysis,AUTISM RESEARCH, Issue 1 2010Karla C. Van Meter Abstract Prenatal environmental exposures are among the risk factors being explored for associations with autism. We applied a new procedure combining multiple scan cluster detection tests to identify geographically defined areas of increased autism incidence. This procedure can serve as a first hypothesis-generating step aimed at localized environmental exposures, but would not be useful for assessing widely distributed exposures, such as household products, nor for exposures from nonpoint sources, such as traffic. Geocoded mothers' residences on 2,453,717 California birth records, 1996,2000, were analyzed including 9,900 autism cases recorded in the California Department of Developmental Services (DDS) database through February 2006 which were matched to their corresponding birth records. We analyzed each of the 21 DDS Regional Center (RC) catchment areas separately because of the wide variation in diagnostic practices. Ten clusters of increased autism risk were identified in eight RC regions, and one Potential Cluster in each of two other RC regions. After determination of clusters, multiple mixed Poisson regression models were fit to assess differences in known demographic autism risk factors between the births within and outside areas of elevated autism incidence, independent of case status. Adjusted for other covariates, the majority of areas of autism clustering were characterized by high parental education, e.g. relative risks >4 for college-graduate vs. nonhigh-school graduate parents. This geographic association possibly occurs because RCs do not actively conduct case finding and parents with lower education are, for various reasons, less likely to successfully seek services. [source] | ||||||||||