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Cell-free DNA (cell-free + dna)
Selected AbstractsSmoking in pregnancy is associated with increased total maternal serum cell-free DNA levelsPRENATAL DIAGNOSIS, Issue 3 2008Adam C. Urato Abstract Objective Cell-free DNA is a marker of cellular apoptosis and necrosis. We wished to determine if maternal smoking affects maternal and fetal serum cell-free DNA levels. Methods Case,control sets of stored second-trimester serum-screening samples from 27 smoking and 90 nonsmoking pregnant women were developed. Smoking status was confirmed by measuring serum cotinine levels. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and DYS1 levels were determined using real-time polymerase chain reaction (PCR) to measure total and fetal cell-free DNA, respectively. At delivery, medical records were reviewed to confirm gender and determine other factors that could affect DNA values. Results Smoking was associated with significantly elevated GAPDH levels compared with nonsmokers (median: 97 662 genome equivalents (GE)/mL vs 38 217 GE/mL; p = 0.018). DYS1 levels were not statistically significantly elevated in smokers (p = 0.29). Other factors that affected DYS1 levels included maternal age in nonsmokers only (r2 = 0.30, p = 0.013) and maternal Synthroid use (p = 0.0045) Conclusion Pregnant smokers have threefold higher levels of total cell-free DNA compared with pregnant nonsmokers. Maternal age and Synthroid exposure may also affect circulating cell-free fetal DNA levels. Copyright © 2008 John Wiley & Sons, Ltd. [source] Digital PCR: a powerful new tool for noninvasive prenatal diagnosis?PRENATAL DIAGNOSIS, Issue 12 2008Bernhard G. Zimmermann Abstract Recent reports have indicated that digital PCR may be useful for the noninvasive detection of fetal aneuploidies by the analysis of cell-free DNA and RNA in maternal plasma or serum. In this review we provide an insight into the underlying technology and its previous application in the determination of the allelic frequencies of oncogenic alterations in cancer specimens. We also provide an indication of how this new technology may prove useful for the detection of fetal aneuploidies and single gene Mendelian disorders. Copyright © 2008 John Wiley & Sons, Ltd. [source] Smoking in pregnancy is associated with increased total maternal serum cell-free DNA levelsPRENATAL DIAGNOSIS, Issue 3 2008Adam C. Urato Abstract Objective Cell-free DNA is a marker of cellular apoptosis and necrosis. We wished to determine if maternal smoking affects maternal and fetal serum cell-free DNA levels. Methods Case,control sets of stored second-trimester serum-screening samples from 27 smoking and 90 nonsmoking pregnant women were developed. Smoking status was confirmed by measuring serum cotinine levels. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and DYS1 levels were determined using real-time polymerase chain reaction (PCR) to measure total and fetal cell-free DNA, respectively. At delivery, medical records were reviewed to confirm gender and determine other factors that could affect DNA values. Results Smoking was associated with significantly elevated GAPDH levels compared with nonsmokers (median: 97 662 genome equivalents (GE)/mL vs 38 217 GE/mL; p = 0.018). DYS1 levels were not statistically significantly elevated in smokers (p = 0.29). Other factors that affected DYS1 levels included maternal age in nonsmokers only (r2 = 0.30, p = 0.013) and maternal Synthroid use (p = 0.0045) Conclusion Pregnant smokers have threefold higher levels of total cell-free DNA compared with pregnant nonsmokers. Maternal age and Synthroid exposure may also affect circulating cell-free fetal DNA levels. Copyright © 2008 John Wiley & Sons, Ltd. [source] Increased cell-free DNA concentrations in patients with obstructive sleep apneaPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 6 2008Chol Shin md Aim:, Blood concentrations of cell-free DNA, which is considered to be released during apoptosis, are elevated under some pathological conditions such as cardiovascular disease and cancer. The association between obstructive sleep apnea (OSA) and cell-free DNA concentrations has not been reported so far. The purpose of the present study was to examine the association between OSA and plasma DNA concentrations. Methods:, A case,control study was conducted using a total of 164 men aged 39,67 years, who were free of coronary heart disease and cancer. Laboratory-based overnight polysomnography was performed for all participants. Results:, On the basis of polysomnography, patients with an apnea,hypopnea index (AHI) = 5,30 events/h were defined as having mild,moderate OSA (n = 33) and those with >30 events/h were defined as having severe OSA (n = 49). All 82 controls had AHI < 5 events/h. Plasma DNA concentrations from all participants were analyzed for the ,-globin gene using fluorescence-based real-time polymerase chain reaction. Patients with severe OSA had significantly higher plasma DNA concentrations than persons with mild,moderate OSA and those without OSA (P < 0.05). AHI was significantly associated with body mass index (P < 0.001), hypertension (P < 0.001), and plasma DNA concentration (P < 0.05). Conclusion:, After taking into account hypertension and other potential risk factors, persons with high plasma DNA concentrations (>8 µg/L) had approximately fourfold higher odds of OSA than those with low DNA levels. Further data are warranted to confirm the association for men and to evaluate the association for women. [source] Circulating tumour-associated plasma DNA represents an independent and informative predictor of prostate cancerBJU INTERNATIONAL, Issue 3 2006FELIX K.-H. OBJECTIVE To investigate whether preoperative plasma levels of free DNA can discriminate between men with localized prostate cancer and benign prostatic hyperplasia (BPH). PATIENTS AND METHODS In all, 161 referred patients suspicious for prostate cancer either by an elevated prostate-specific antigen (PSA) level and/or abnormal digital rectal examination (DRE) were included in this prospective study. Peripheral plasma was taken before prostate biopsy and genomic DNA was extracted from the plasma using the a commercial kit and a vacuum chamber. After controlling for age, PSA level, the percentage free/total (f/t) PSA and prostate volume, the median prostate cancer plasma DNA concentration served as diagnostic threshold in uni- and multivariate logistic regression models. Multivariate models were subjected to 200 bootstraps for internal validation and to reduce over-fit bias. RESULTS Subgroups consisted of 142 men with clinically localized prostate cancer and 19 with BPH. The median plasma concentration of cell-free DNA was 267 ng/mL in men with BPH vs 709 ng/mL in men with prostate cancer. In univariate analyses, plasma DNA concentration was a statistically significant and informative predictor (P = 0.032 and predictive accuracy 0.643). In multivariate analyses, it remained statistically significant after controlling for age, tPSA, f/tPSA and prostate volume, increasing the predictive accuracy by 5.6%. CONCLUSIONS Our data suggest that plasma DNA level is a highly accurate and informative predictor in uni- and multivariate models for the presence of prostate cancer on needle biopsy. The predictive accuracy was substantially increased by adding plasma DNA level. However, larger-scale studies are needed to further confirm its clinical impact on prostate cancer detection. [source] | ||||||||||