Cell-free DNA (cfDNA) in body tissues or fluids is extensively investigated in clinical medicine and other research fields. In this article we provide a direct quantitative real-time PCR (qPCR) as a sensitive tool for the measurement of cfDNA from plasma without previous DNA extraction, which is known to be accompanied by a reduction of DNA yield. The primer sets were designed to amplify a 90 and 222 bp multi-locus L1PA2 sequence. In the first module, cfDNA concentrations in unpurified plasma were compared to cfDNA concentrations in the eluate and the flow-through of the QIAamp DNA Blood Mini Kit and in the eluate of a phenol-chloroform isoamyl (PCI) based DNA extraction, to elucidate the DNA losses during extraction. The analyses revealed 2.79-fold higher cfDNA concentrations in unpurified plasma compared to the eluate of the QIAamp DNA Blood Mini Kit, while 36.7% of the total cfDNA were found in the flow-through. The PCI procedure only performed well on samples with high cfDNA concentrations, showing 87.4% of the concentrations measured in plasma. The DNA integrity strongly depended on the sample treatment. Further qualitative analyses indicated differing fractions of cfDNA fragment lengths in the eluate of both extraction methods. In the second module, cfDNA concentrations in the plasma of 74 coronary heart disease patients were compared to cfDNA concentrations of 74 healthy controls, using the direct L1PA2 qPCR for cfDNA quantification. The patient collective showed significantly higher cfDNA levels (mean (SD) 20.1 (23.8) ng/ml; range 5.1–183.0 ng/ml) compared to the healthy controls (9.7 (4.2) ng/ml; range 1.6–23.7 ng/ml). With our direct qPCR, we recommend a simple, economic and sensitive procedure for the quantification of cfDNA concentrations from plasma that might find broad applicability, if cfDNA became an established marker in the assessment of pathophysiological conditions.
OBJECTIVEThis study compared the long-term efficacy of a diabetes-specific cognitive behavioral group therapy (CBT) with sertraline in patients with diabetes and depression who initially responded to short-term depression treatment.
RESEARCH DESIGN AND METHODSA randomized controlled single-blind trial was conducted in 70 secondary care centers across Germany comparing 12 weeks of CBT with sertraline in 251 patients with type 1 or 2 diabetes (mean HbA 1c 9.3%, 78 mmol/mol) and major depression (Structured Clinical Interview for DSM-IV [SCID]). After 12 weeks, treatment responders ( ‡50% reduction Hamilton Depression Rating Scale ) were included in the 1-year study phase where CBT patients were encouraged to use bibliotherapy and sertraline patients received continuous treatment. We analyzed differences for HbA 1c (primary outcome) and reduction (HAMD-17) or remission (SCID) of depression from baseline to the 1-year follow-up using ANCOVA or logistic regression analysis.
RESULTSAfter 12 weeks, 45.8% of patients responded to antidepressant treatment and were included in the 1-year study phase. Adjusted HbA 1c mean score changes from baseline to the end of the long-term phase (20.27, 95% CI 20.62 to 0.08) revealed no significant difference between interventions. Depression improved in both groups, with a significant advantage for sertraline (HAMD-17 change: 22.59, 95% CI 1.15-4.04, P < 0.05).
CONCLUSIONSDepression improved under CBT and sertraline in patients with diabetes and depression, with a significant advantage for sertraline, but glycemic control remained unchanged. CBT and sertraline as single treatment are insufficient to treat secondary care diabetes patients with depression and poor glycemic control.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.