Transmission routes and reservoirs need to be elucidated.

No abstract

Magnetic Fe3O4nanoparticles were prepared by coprecipitation and then coated with silica. These Fe3O4/SiO2nanoparticles consisted of a 10–15 nm magnetic core and a silica shell of 2–5 nm thickness. The superparamagnetic property of the Fe3O4/SiO2particles with the magnetization of 42.5 emu/g was confirmed by vibrating sample magnetometer (VSM). We further optimized buffers with these Fe3O4/SiO2nanoparticles to isolate genomic DNA of hepatitis virus type B (HBV) and of Epstein-Barr virus (EBV) for detection of the viruses based on polymerase chain reaction (PCR) amplification of a 434 bp fragment ofSgene specific for HBV and 250 bp fragment of nuclear antigen encoding gene specific for EBV. The purification efficiency of DNA of both HBV and EBV using obtained Fe3O4/SiO2nanoparticles was superior to that obtained with commercialized Fe3O4/SiO2microparticles, as indicated by (i) brighter PCR-amplified bands for both HBV and EBV and (ii) higher sensitivity in PCR-based detection of EBV load (copies/mL). The time required for DNA isolation using Fe3O4/SiO2nanoparticles was significantly reduced as the particles were attracted to magnets more quickly (15–20 s) than the commercialized microparticles (2-3 min).

No abstract

During dengue fever, a pronounced gamma-interferon immune response produces neopterin and promotes tryptophan degradation by the enzyme indoleamine-2,3-dioxygenase 1 (IDO-1). Activated IDO-1 is indicated by an increased kynurenine to tryptophan ratio (Kyn/Trp) in patients. Methods: Plasma levels of neopterin, kynurenine, and tryptophan were measured in 72 hospitalized dengue virus (DENV) patients and 100 healthy individuals. Plasma levels of neopterin, kynurenine, and tryptophan were also measured prospectively in a second cohort of 13 DENV patients; on the day of hospitalization, on day 2-3 at discharge, and 7-10 days after discharge. DENV RNA positivity was determined by qualitative and quantitative methodologies. Results: DENV RNA-positive patients presented significantly higher levels of neopterin (mean 36.5 nmol/l) and Kyn/Trp ratios (mean 102 mmol/mmol) compared to DENV RNA-negative individuals. A significant correlation between neopterin levels and Kyn/Trp ratios was observed in both DENV RNA-positive (Spearman's rho = 0.37, p < 0.01) and DENV RNA-negative (Spearman's rho = 0.89, p < 0.001) patients. Kyn/Trp ratios were negatively correlated with platelet counts (Spearman's rho = À0.43, p < 0.01) and positively correlated with liver enzymes: AST (Spearman's rho = 0.68, p < 0.01) and ALT (Spearman's rho = 0.51, p < 0.05). In addition, the follow-up data presented a significant decrease in neopterin levels and Kyn/Trp ratios within 10 days after hospital entry. Conclusions: Neopterin levels and Kyn/Trp ratios were significantly increased in DENV patients and subsequently decreased after recovery.