Use of plasma DNA to predict mortality and need for intensive care in patients with abdominal pain

Background We investigated the value of plasma deoxyribonucleic acid concentrations in patients presenting with acute abdominal pain to predict need for intensive care or mortality. Methods Plasma deoxyribonucleic acid taken from patients with acute abdominal pain was analyzed for the β-globin gene using the quantitative polymerase chain reaction. The primary outcome measure was the combined 28-day mortality or admission to the intensive care unit. Results Of 287 consecutive patients with acute abdominal pain recruited, 12 patients were admitted to the intensive care unit and/or died. Median plasma DNA concentrations were higher in patients with cancer and major organ inflammation. Mean plasma DNA concentrations were three-fold higher in patients with systemic inflammatory response syndrome, five-fold higher in patients who died within 28 days, and eight-fold higher in patients admitted to the intensive care unit. The area under the receiver operator curve for plasma DNA concentrations and intensive care unit admission/mortality was 0.804. At a cut-off of 1100 GE/ml, the sensitivity was 67% (95%CI 35–90) and specificity was 89% (95%CI 84–92). At a cut-off of 175 GE/ml, the sensitivity was 100% (95%CI 73–100) and specificity was 30% (95%CI 25–36). Plasma DNA concentration predicted need for intensive care unit admission or death (adjusted odds ratio 1.4; P < 0.0001). Conclusions Plasma DNA may have a role in patients with acute abdominal pain as a marker for inflammation and cancer, and a predictor of intensive care unit admission/mortality

Quantitative analysis of circulating mitochondrial DNA in plasma

Background: Recent studies have demonstrated the existence of circulating mitochondrial DNA in plasma and serum, but the concentrations and physical characteristics of circulating mitochondrial DNA are unknown. The aim of this study was to develop an assay to quantify mitochondrial DNA in the plasma of healthy individuals. Methods: We adopted a real-time quantitative PCR approach and evaluated the specificity of the assay for detecting mitochondrial DNA with a cell line (ρ0) devoid of mitochondria. The concentrations and physical characteristics of circulating mitochondrial DNA were investigated by experiments conducted in three modules. In module 1, we evaluated the concentrations of mitochondrial DNA in plasma aliquots derived from four blood-processing protocols. In module 2, we investigated the existence of both particle-associated and free forms of mitochondrial DNA in plasma by subjecting plasma to filtration and ultracentrifugation. In module 3, we used filters with different pore sizes to investigate the size characteristics of the particle-associated fraction of circulating mitochondrial DNA. Results: The mitochondrial DNA-specific, real-time quantitative PCR had a dynamic range of five orders of magnitude and a sensitivity that enabled detection of one copy of mitochondrial DNA in plasma. In module 1, we found significant differences in the amounts of circulating mitochondrial DNA among plasma aliquots processed by different methods. Data from module 2 revealed that a significant fraction of mitochondrial DNA in plasma was filterable or pelletable by ultracentrifugation. Module 3 demonstrated that filters with different pore sizes removed mitochondrial DNA from plasma to different degrees. Conclusions: Both particle-associated and free mitochondrial DNA are present in plasma, and their respective concentrations are affected by the process used to harvest plasma from whole blood. These results may have implications in the design of future studies on circulating mitochondrial DNA measured in different disease conditions

Aberrant concentrations of liver-derived plasma albumin mRNA in liver pathologies

Background: We hypothesized that liver-derived mRNA, such as ALB (albumin) mRNA, would be released into human plasma with liver cell death. Methods: We genotyped ALB mRNA molecules in samples of plasma and whole blood from liver and bone marrow transplant recipients by RNA single-nucleotide polymorphism analysis. Plasma and whole blood ALB mRNA genotypes were compared with the DNA genotypes of the recipients and donors. A reverse-transcription quantitative real-time PCR assay was used to measure plasma ALB mRNA concentrations in 107 patients [hepatocellular carcinoma (HCC), cirrhosis, or chronic hepatitis B (CHB)] and 207 healthy controls. Results: The RNA genotype data revealed ALB mRNA in plasma to be liver derived, whereas tissue compartments other than the liver also contributed to the ALB mRNA detected in whole blood. Statistically significant increases in plasma ALB mRNA concentrations were observed for HCC, cirrhosis, and active CHB, compared with controls. A cutoff of 835 copies/mL of plasma ALB mRNA identified by ROC curve analysis showed 85.5% diagnostic sensitivity and 92.8% diagnostic specificity for the detection of liver pathologies. Only 21.5% of patients with liver pathologies had increased alanine aminotransferase (ALT) activities, whereas 73.8% had increased plasma ALB mRNA concentrations. Only 48.6% of the HCC patients had increased serum α-fetoprotein concentrations, whereas 91.4% had increased plasma ALB mRNA concentrations. Conclusions: ALB mRNA is liver specific in plasma, but not in whole blood. Plasma ALB mRNA is increased in some liver pathologies and may be more diagnostically sensitive than α-fetoprotein and ALT

Opportunism as the Inhibiting Trigger for Developing Long-Term-Oriented Western Exporter-Hong Kong Importer Relationships

Notwithstanding the extensive literature on opportunism in buyer–seller relationships, scant empirical attention has been given to this issue in both international and Chinese contexts. Using a sample of 202 Hong Kong Chinese importers, this article highlights the harmful effect of Western exporters' opportunism on importers' long-term orientation through the intervening role of key behavioral constructs. The study confirms almost all hypothesized associations between the constructs examined, indicating that an exporter's opportunistic behavior reduces trust and generates conflict. In turn, low trust reduces commitment, and conflict impedes communication. Low levels of both commitment and communication reduce importers' satisfaction, which inhibits their long-term orientation. The importer's proactive initiation of the relationship moderates the link between opportunism and trust but not that of opportunism with conflict. The study also confirms the moderating role of importer dependence and exporters' marketing adaptation on the association of satisfaction with long-term orientation. The authors find moderating effects on this association through the Chinese constructs of renqing and mianzi, albeit in the opposite direction to that hypothesized