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A fast and convenient headspace gas chromatographic (HS-GC) approach was described for the estimation of urea in human urine. The HS-GC could detect the generated carbon dioxide derived from the urease-catalyzed hydrolysis of urea. It was found that the hydrolysis of urea catalyzed by urease was completed within 40 min at 35 °C. The results proved the great accuracy (relative errors ≤ 8.48%) and precision (RSD ≤ 2.66%) of the HS-GC approach. Moreover, the recoveries ranged from 97.9% to 101.5%. The new approach is rapid and automated, which provides a new way to routinely analyze urea in urine for the control of metabolic disease. • A fast HS-GC method was described for the estimation of urea in human urine. • The HS-GC could detect the generated carbon dioxide from the hydrolysis of urea. • The new approach provides a new way to routinely analyze urea in urine. [ABSTRACT FROM AUTHOR]

The differential capacitance of a model organic electrolyte in a cylindrical pore that is so narrow that the ions can form only a single file is studied by means of density functional theory (DFT). Kornyshev (2013), has studied this system and found the differential capacitance to have only a double hump shape (the so-called camel shape) whereas other geometries show this behavior only at low ionic concentrations that are typical for aqueous electrolytes. However, his calculation is rather approximate. In this DFT study we find that the double hump shape occurs only at low ionic concentrations. At high concentrations, the capacitance has only a single hump. Kornyshev considers a metallic cylinder and approximately includes the contributions of electrostatic images. Electrostatic images are not easily incorporated into DFT. As a result, images are not considered in this study and the question of whether Kornyshev’s result is due to his approximations or images cannot be answered. Simulations to answer this question are planned. [ABSTRACT FROM AUTHOR]

Abstract: Patients with cancer frequently develop autoantibodies, and the identification of panels of tumor autoantigens may have utility in early cancer diagnosis and immunotherapy. This study aims to exploit the autoantibody repertoire in pancreatic cancer and identify the possible serum marker for pancreatic cancer. Sera from 55 newly diagnosed patients with pancreatic cancer and 52 healthy controls were analyzed for antibody-based reactivity against Hep-2, a human larynx epithelioma cancer cell line, with one-dimensional immunoblot assay. From this analysis, we observed a prominent band with a molecular weight of 47kDa in 63.64% (35/55) patients, while in only 1.9% normal group (1/52). Using immunoblot analysis after two-dimensional electrophoresis combined with liquid chromatography–electrospray ionization tandem mass spectrometry, this target antigen was identified as DEAD-box protein 48 (DDX48). BLAST analysis showed that it was highly similar to eukaryotic initiation factor 4A and might play a role in pre-mRNA processing. An enzyme-linked immunosorbent assay was performed using recombinant, purified DDX48 as an antigen to detect anti-DDX48 autoantibodies in sera. Reactivity was observed in 20 of 60 (33.33%) pancreatic cancer patients, 3 of 30 (10.00%) colorectal cancer patients, 2 of 30 (6.67%) gastric cancer patients, 2 of 30 (6.67%) hepatocellular cancer patients, while none of the 20 chronic pancreatitis patients, 30 lung cancer patients, and 60 normal individuals. Together, these results demonstrate that the detection of autoantibodies to DDX48 may have clinical utility for the improved diagnosis of pancreatic cancer. [Copyright &y& Elsevier]

The results of the RV144 vaccine clinical trial showed a correlation between high level of anti-V1V2 antibodies (Abs) and a decreased risk of acquiring HIV-1 infection. This turned the focus of HIV vaccine design to the induction of elevated levels of anti-V2 Abs to increase vaccine efficacy. In plasma samples from HIV-1 infected Cameroonian individuals, we observed broad variations in levels of anti-V2 Abs, and 6 of the 79 plasma samples tested longitudinally displayed substantial deficiency of V2 Abs. Sequence analysis of the V2 region from plasma viruses and multivariate analyses of V2 characteristics showed a significant difference in several features between V2-deficient and V2-reactive plasma Abs. These results suggest that HIV vaccine immunogens containing a shorter V2 region with fewer glycosylation sites and higher electrostatic charges can be beneficial for induction of a higher level of anti-V2 Abs and thus contribute to HIV vaccine efficacy. [ABSTRACT FROM AUTHOR]

Abstract: To investigate essential factors that determine the efficacy of vaccines against lentiviruses, an effective attenuated equine infectious anemia virus (EIAV) vaccine strain and a proviral derivative of the vaccine were compared with respect to differences in inducing protective immunity. Although these two strains replicated equally well in vitro and in vivo, the proviral strain induced significantly less protection from disease and infection caused by viral challenge and significantly lower specific neutralizing capability. These findings indicated that the proviral strain had lost the ability to stimulate immune protection compared to the parental vaccine strain. A further analysis of the envelope gp90 gene variation revealed that compared to the proviral strain, the vaccine strain displayed a wide sequence diversity in immunogen composition. Thus, we inferred that the differences in immunogen composition might be the major cause for the failure of the proviral derivative to elicit the immune protection induced by the parental strain. [ABSTRACT FROM AUTHOR]