Mycobacterium kansasii has emerged as an important nontuberculous mycobacterium pathogen, whose incidence and prevalence have been increasing in the last decade. M. kansasii can cause pulmonary tuberculosis clinically and radiographically indistinguishable from that caused by Mycobacterium tuberculosis infection. Unlike the widely-studied M. tuberculosis, little is known about the innate immune response against M. kansasii infection. Although inflammasome activation plays an important role in host defense against bacterial infection, its role against atypical mycobacteria remains poorly understood. In this report, the role of inflammasome activity in THP-1 macrophages against M. kansasii infection was studied. Results indicated that viable, but not heat-killed, M. kansasii induced caspase-1-dependent IL-1β secretion in macrophages. The underlying mechanism was found to be through activation of an inflammasome containing the NLR (Nod-like receptor) family member NLRP3 and the adaptor protein ASC (apoptosis-associated speck-like protein containing a CARD). Further, potassium efflux, lysosomal acidification, ROS production and cathepsin B release played a role in M. kansasii-induced inflammasome activation. Finally, the secreted IL-1β derived from caspase-1 activation was shown to restrict intracellular M. kansasii. These findings demonstrate a biological role for the NLRP3 inflammasome in host defense against M. kansasii.

An automatic method for disulfide bond assignment using dimethyl labeling and computational screening of a1 ions with customized software, RADAR, is developed. Utilizing the enhanced a1 ions generated from labeled peptides, the N-terminal amino acids from disulfide-linked peptides can be determined. In this study, we applied this method for structural characterization of recombinant monoclonal antibodies, an important group of therapeutic proteins. In addition to a1 ion screening and molecular weight match, new RADAR is capable of confirming the matched peptide pairs by further comparing the CID fragment ions. With the N-terminal amino acid identities as a threshold, the identification of disulfide-linked peptide pairs can be achieved rapidly at a higher confidence level. Unlike majorities of the current approaches, prior knowledge of disulfide linkages or a high- end mass spectrometry is not required, and tedious labor work or deliberate interpretation can be avoided in this study. Our approach makes it possible to analyze unknown disulfide bonds of protein pharmaceuticals as well as their degraded forms without further protein separation. It can be used as a convenient quality examination tool during biopharmaceutical development and manufacturing processes.

We propose a united-residue model of membrane proteins to investigate the structures of helix bundle membrane proteins (HBMPs) using coarse-grained (CG) replica exchange Monte-Carlo (REMC) simulations. To demonstrate the method, it is used to identify the ground state of HBMPs in a CG model, including bacteriorhodopsin (BR), halorhodopsin (HR), and their subdomains. The rotational parameters of transmembrane helices (TMHs) are extracted directly from the simulations, which can be compared with their experimental measurements from site-directed dichroism. In particular, the effects of amphiphilic interaction among the surfaces of TMHs on the rotational angles of helices are discussed. The proposed CG model gives a reasonably good structure prediction of HBMPs, as well as a clear physical picture for the packing, tilting, orientation, and rotation of TMHs. The root mean square deviation (RMSD) in coordinates of C(α) atoms of the ground state CG structure from the X-ray structure is 5.03 Å for BR and 6.70 Å for HR. The final structure of HBMPs is obtained from the all-atom molecular dynamics simulations by refining the predicted CG structure, whose RMSD is 4.38 Å for BR and 5.70 Å for HR.

Food safety research has shown that the use of a food thermometer is the best way to ensure that meat, poultry, and other foods reach an internal temperature sufficient to destroy foodborne pathogens. The 1998, 2001, 2006, and 2010 Food Safety Surveys were used to analyze changes in food thermometer ownership and usage for roasts, chicken parts, and hamburgers in the United States. A probit regression model was used to evaluate differing trends in ownership across demographic subgroups, and probit models with sample selection were used to evaluate differing trends in food thermometer usage for roasts, chicken parts, and hamburgers. The Food Safety Surveys are nationally representative telephone surveys tracking consumers' food safety attitudes and behaviors. Findings from these surveys indicate that the percentage of consumers who own food thermometers has increased from 49% in 1998 to 70% in 2010 (P < 0.05). The use of food thermometers has also increased over this time period but varies by food type. Of those who own food thermometers, a higher percentage reported using thermometers for roasts (76% in 1998 and 82% in 2010, P < 0.05) than for chicken parts (33% in 1998 and 53% in 2010, P < 0.05) and hamburgers (14% in 1998 and 23% in 2010, P < 0.05). The results also show that men, non-Hispanic whites, those with some college education or higher, those with higher incomes, and those 65 years and older were more likely to own food thermometers. After controlling for food thermometer ownership, those aged 18 to 29 years were more likely to use a food thermometer for roasts and chicken parts than those aged 65 to 101 years. The results suggest that educational programs encouraging food thermometer usage should focus first on food thermometer ownership.

BACKGROUND: The optimal dosage of intravenous proton pump inhibitors (PPIs) for the prevention of peptic ulcer rebleeding remains unclear. AIM: To compare the rebleeding rate of high-dose and standard-dose PPI use after endoscopic haemostasis. METHODS: A total of 201 patients with bleeding ulcers undergoing endoscopic treatment with epinephrine injection and heater probe thermocoagulation were randomised to receive a high-dose regimen (80 mg bolus, followed by pantoprazole 8 mg/h infusion, n = 100) or a standard-dose regimen (pantoprazole 40 mg bolus daily, n = 101). After 72 h, all patients were given 40 mg pantoprazole daily orally for 27 days. RESULTS: There were no statistical differences in mean units of blood transfused, length of hospitalisation ≦5 days, surgical or radiological interventions and mortality within 30 days between two groups. Bleeding recurred within 30 days in six patients [6.2%, 95% confidence interval (CI) 1.3-11.1%] in the high-dose group, as compared to five patients (5.2%, 95% CI 0.6-9.7%) in the standard-dose group (P = 0.77). The stepwise Cox regression analysis showed end-stage renal disease, haematemesis, chronic obstructive pulmonary disease (hazard ratio: 37.15, 10.07, 9.12, 95% CI: 6.76-204.14, 2.07-49.01, 1.66-50.00 respectively) were independent risk factors for rebleeding and Helicobacter pylori infection was associated with lower risk of rebleeding (hazard ratio: 0.20, 95% CI: 0.04-0.94). CONCLUSIONS: Following combined endoscopic haemostasis of bleeding ulcers, co-morbidities, haematemesis and H. pylori Status, but not PPI dosage, are associated with rebleeding (http://www.Clinical Trials.gov.ID: NCT00709046).

The objective was to develop a high-throughput method of identifying sex in both Coturnix chinensis and Gallus gallus, which would be useful for biomedical research and hatcheries. Because chromo-helicase-DNA binding protein (CHD)-based Griffiths P2/P8 primers do not produce polymerase chain reaction (PCR) products with distinguishable sex-specific curves in melting curve analysis (MCA), these primers are unsuitable for high throughput application in either species. Conserved regions were identified by basic local alignment search tool (BLAST) analyses of cloned CHD-Z and CHD-W genes of C. chinensis. Based on sequence alignment, a female-specific CHD-W primer (W-cot-F1) and a female/male (or CHD-W/CHD-Z)-common primer (ZW-cot-F1) were redesigned for use in combination with the Griffiths P2 primer for MCA-based PCR reaction. In C. chinensis and G. gallus, W-cot-F1/P2 and ZW-cot-F1/P2 had amplicon lengths of 315/318 and 114 base pairs and melting temperatures (Tm) of approximately 79.5 °C to 80 (o)C and approximately 78.5 °C to 79°C, respectively. Thus, MCA distinguished sex based on two distinct Tm peaks in females versus only one Tm peak in males. The MCA-based real-time PCR combined with the proposed primer redesign provided a high-throughput method of identifying sex in C. chinensis and G. gallus.

The focus of this study was to evaluate the safety and efficacy of sequential peginterferon α-2a (Pegasys) therapy for chronic hepatitis B with acute exacerbation [ALT > 10 × upper limit of normal (ULN), bilirubin <2.0 mg/dL]. Four groups of patients categorized by HBeAg status and treatment regimens were studied since May 2007. Nineteen HBeAg-positive patients (Group 1) had received entecavir  pretreatment  (when ALT > 10 × ULN) plus Pegasys (180 μg/kg/week, when ALT was 5-10 × ULN) for 24 weeks. Thirteen HBeAg-negative patients (Group 2) had the same protocol for 48 weeks. In both groups, entecavir was then discontinued 14 days after the initiation of Pegasys. The results were compared, respectively, to 35 HBeAg-positive patients (Group 3) and 24 HBeAg-negative patients (Group 4), all with ALT > 5 × ULN, under continual entecavir monotherapy. The ALT levels of patients in Group 1 and 2 who had received entecavir pretreatment for a duration of 19.63 ± 3.34 days were below four times of ULN following 4 weeks of Pegasys treatment. At week 96, the rates of sustained virological response were 69.2%(9/13) and 80%(8/10), and the relapse rates were 23.1%(3/13) and 11.2%(1/9) for HBeAg-positive and HBeAg-negative patients with two-step Pegasys treatment, respectively. The HBeAg seroconversion rates were 46.2% in Group 1, and 42.1% in Group 3; HBsAg loss rates were 15.4%(2/13) in Group 1, and 30%(3/10) in Group 2, whereas none achieved HBsAg loss with entecavir monotherapy (Group 3 and 4). The two-step Pegasys treatment offers an alternative, other than the nucleos(t)ides, for treating chronic hepatitis B with acute exacerbation and provides a safe, efficacious, short-term and finite strategy.

Humic substances are a major component of soil organic matter that influence the behavior and fate of heavy metals such as Cr(VI), a toxic and carcinogenic element. In the study, a repetitive extraction technique was used to fractionate humic acids (HAs) from a peat soil into three fractions (denoted as F1, F2, and F3), and the relative importance of O-containing aromatic and aliphatic domains in humic substances for scavenging Cr(VI) was addressed at pH 1. Spectroscopic analyses indicated that the concentrations of aromatic C and O-containing functional groups decreased with a progressive extraction as follows: F1>F2>F3. Cr(VI) removal by HA proceeded slowly, but it was enhanced when light was applied due to the production of efficient reductants, such as superoxide radical and H(2)O(2), for Cr(VI). Higher aromatic- and O-containing F1 fraction exhibited a greater efficiency for Cr(VI) reduction (with a removal rate of ca. 2.89 mmol g(-1) HA under illumination for 3 h).(13)C NMR and FTIR spectra further demonstrated that the carboxyl groups were primarily responsible for Cr(VI) reduction. This study implied the mobility and fate of Cr(VI) would be greatly inhibited in the environments containing such organic groups.