Rapid expression and purification of the hepatitis delta virus antigen using the methylotropic yeast Pichia pastoris

Objective: Patients with dual hepatitis B (HBV) and hepatitis D (HDV) virus infection are at an increased risk of progression to liver cirrhosis and hepatocellular carcinoma than patients with a single viral infection. Treatment of viral hepatitis due to dual HBV/HDV infection represents a challenge. Currently there is no vaccine against HDV. Recombinant production of HDV antigen (HDAg) is the first step towards a potential vaccine candidate and the development of assays for HDV detection. Results: This study demonstrates the expression of one HDAg isoform, S-HDAg, in Pichia pastoris. A recombinant vector carrying a tagged gene encoding S-HDAg under the control of the methanol-inducible promoter AOX1 was designed and integrated into P. pastoris X33. The protein, which was purified using a Ni2+ affinity column and eluted at 100-150 mM imidazole, has potential as a recombinant antigen for further study

Molecular Cloning of a New Immunomodulatory Protein from Anoectochilus formosanus which Induces B Cell IgM Secretion through a T-Independent Mechanism

An immunomodulatory protein (IPAF) was purified and cloned from Anoectochilus formosanus, an Orchidaceae herbal plant in Asia. The major targeting immune cells of IPAF and its modulating effects toward B lymphocytes were investigated. Rapid amplification of cDNA ends (RACE) was conducted to clone the IPAF gene, and the obtained sequence was BLAST compared on the NCBI database. MACS-purified mouse T and B lymphocytes were stimulated with IPAF and the cell proliferation, activation, and Igs production were examined. IPAF comprised a 25 amino acids signal peptide and a 138 amino acids protein which was homologous to the lectins from Orchidaceae plant. IPAF selectively induced the cell proliferation in mouse splenic B lymphocytes but not T lymphocytes. The IPAF-induced B cells exhibited increased CD69 and MHC class II expression, and a dose- and time-dependent enhancement in IgM production. These results suggested potential benefits of IPAF to strengthen the humoral immunity

Trans-boundary air pollution in a Southeast Asian megacity: Case studies of the synoptic meteorological mechanisms and impacts on air quality

Local and regional sources contribute to degraded air quality in many urban areas, however, the influence of trans-boundary air pollution on surface PM2.5 is still poorly characterized in Southeast Asia (SEA) megacities. This study, for the first time, utilizes multi-platform datasets to elucidate two trans-boundary PM2.5 episodes in Ho Chi Minh City (HCMC), Vietnam, over the periods 25–29 Oct 2013 and 05–08 Oct 2015. Both events persisted with limited diurnal fluctuations and more than 60% of the Air Quality Index (AQI) values at an unhealthy level. PM2.5 concentrations during the events were 100% and 115% higher on average compared to local accumulation periods in the same months, highlighting the importance of trans-boundary pollution to local HCMC air quality. Backward trajectories, MERRA-2 AOD data, and CALIPSO images revealed the origin and synoptic meteorology conditions facilitating both trans-boundary pollution events. Anthropogenic PM2.5 emissions in continental East Asia fed the 2013 event, which was then transported by strong northeasterly winds triggered by an upper-level ridge near the Tibetan Plateau and a low-pressure system in western Pacific Ocean. In contrast, the 2015 event was the result of Indonesia biomass burning (BB), which was enhanced and transported by a westward propagating Western Pacific Subtropical High triggered by a strong El Nino ˜ event. Future climate change will likely increase the number of extreme El Nino ˜ events, leading to the increase of transboundary Indonesia BB events to HCMC. This study lays the groundwork for detailing the impact of trans-boundary pollution on local air quality in SEA megacities

Computing H/D-Exchange rates of single residues from data of proteolytic fragments

<p>Abstract</p> <p>Background</p> <p>Protein conformation and protein/protein interaction can be elucidated by solution-phase Hydrogen/Deuterium exchange (sHDX) coupled to high-resolution mass analysis of the digested protein or protein complex. In sHDX experiments mutant proteins are compared to wild-type proteins or a ligand is added to the protein and compared to the wild-type protein (or mutant). The number of deuteriums incorporated into the polypeptides generated from the protease digest of the protein is related to the solvent accessibility of amide protons within the original protein construct.</p> <p>Results</p> <p>In this work, sHDX data was collected on a 14.5 T FT-ICR MS. An algorithm was developed based on combinatorial optimization that predicts deuterium exchange with high spatial resolution based on the sHDX data of overlapping proteolytic fragments. Often the algorithm assigns deuterium exchange with single residue resolution.</p> <p>Conclusions</p> <p>With our new method it is possible to automatically determine deuterium exchange with higher spatial resolution than the level of digested fragments.</p

Increased Risk of Vascular Events in Emergency Room Patients Discharged Home with Diagnosis of Dizziness or Vertigo: A 3-Year Follow-Up Study

BACKGROUND: Dizziness and vertigo symptoms are commonly seen in emergency room (ER). However, these patients are often discharged without a definite diagnosis. Conflicting data regarding the vascular event risk among the dizziness or vertigo patients have been reported. This study aims to determine the risk of developing stroke or cardiovascular events in ER patients discharged home with a diagnosis of dizziness or vertigo. METHODOLOGY: A total of 25,757 subjects with at least one ER visit in 2004 were identified. Of those, 1,118 patients were discharged home with a diagnosis of vertigo or dizziness. A Cox proportional hazard model was performed to compare the three-year vascular event-free survival rates between the dizziness/vertigo patients and those without dizziness/vertigo after adjusting for confounding and risk factors. RESULTS: We identified 52 (4.7%) vascular events in patients with dizziness/vertigo and 454 (1.8%) vascular events in patients without dizziness/vertigo. ER patients discharged home with a diagnosis of vertigo or dizziness had 2-fold (95% confidence interval [CI], 1.35-2.96; p<0.001) higher risk of stroke or cardiovascular events after adjusting for patient characteristics, co-morbidities, urbanization level of residence, individual socio-economic status, and initially taking medications after the onset of dizziness or vertigo during the first year. CONCLUSIONS: ER patients discharged home with a diagnosis of dizziness or vertigo were at a increased risk of developing subsequent vascular events than those without dizziness/vertigo after the onset of dizziness or vertigo. Further studies are warranted for developing better diagnostic and follow-up strategies in increased risk patients

Patient satisfaction and side effects in primary care: An observational study comparing homeopathy and conventional medicine

<p>Abstract</p> <p>Background</p> <p>This study is part of a nationwide evaluation of complementary medicine in Switzerland (Programme Evaluation of Complementary Medicine PEK) and was funded by the Swiss Federal Office of Public Health. The main objective of this study is to investigate patient satisfaction and perception of side effects in homeopathy compared with conventional care in a primary care setting.</p> <p>Methods</p> <p>We examined data from two cross-sectional studies conducted in 2002–2003. The first study was a physician questionnaire assessing structural characteristics of practices. The second study was conducted on four given days during a 12-month period in 2002/2003 using a physician and patient questionnaire at consultation and a patient questionnaire mailed to the patient one month later (including Europep questionnaire).</p> <p>The participating physicians were all trained and licensed in conventional medicine. An additional qualification was required for medical doctors providing homeopathy (membership in the Swiss association of homeopathic physicians SVHA).</p> <p>Results</p> <p>A total of 6778 adult patients received the questionnaire and 3126 responded (46.1%). Statistically significant differences were found with respect to health status (higher percentage of chronic and severe conditions in the homeopathic group), perception of side effects (higher percentage of reported side effects in the conventional group) and patient satisfaction (higher percentage of satisfied patients in the homeopathic group).</p> <p>Conclusion</p> <p>Overall patient satisfaction was significantly higher in homeopathic than in conventional care. Homeopathic treatments were perceived as a low-risk therapy with two to three times fewer side effects than conventional care</p

Monitoring and Characterization of Oseltamivir-Resistant Pandemic (H1N1) 2009 Virus, Japan, 2009–2010

No evidence of sustained spread was found, but 2 incidents of human-to-human transmission were suspected

Strength of Hydrogen Bond Network Takes Crucial Roles in the Dissociation Process of Inhibitors from the HIV-1 Protease Binding Pocket

To understand the underlying mechanisms of significant differences in dissociation rate constant among different inhibitors for HIV-1 protease, we performed steered molecular dynamics (SMD) simulations to analyze the entire dissociation processes of inhibitors from the binding pocket of protease at atomistic details. We found that the strength of hydrogen bond network between inhibitor and the protease takes crucial roles in the dissociation process. We showed that the hydrogen bond network in the cyclic urea inhibitors AHA001/XK263 is less stable than that of the approved inhibitor ABT538 because of their large differences in the structures of the networks. In the cyclic urea inhibitor bound complex, the hydrogen bonds often distribute at the flap tips and the active site. In contrast, there are additional accessorial hydrogen bonds formed at the lateral sides of the flaps and the active site in the ABT538 bound complex, which take crucial roles in stabilizing the hydrogen bond network. In addition, the water molecule W301 also plays important roles in stabilizing the hydrogen bond network through its flexible movement by acting as a collision buffer and helping the rebinding of hydrogen bonds at the flap tips. Because of its high stability, the hydrogen bond network of ABT538 complex can work together with the hydrophobic clusters to resist the dissociation, resulting in much lower dissociation rate constant than those of cyclic urea inhibitor complexes. This study may provide useful guidelines for design of novel potent inhibitors with optimized interactions

Dynamic temporary blood facility location-allocation during and post-disaster periods

The key objective of this study is to develop a tool (hybridization or integration of different techniques) for locating the temporary blood banks during and post-disaster conditions that could serve the hospitals with minimum response time. We have used temporary blood centers, which must be located in such a way that it is able to serve the demand of hospitals in nearby region within a shorter duration. We are locating the temporary blood centres for which we are minimizing the maximum distance with hospitals. We have used Tabu search heuristic method to calculate the optimal number of temporary blood centres considering cost components. In addition, we employ Bayesian belief network to prioritize the factors for locating the temporary blood facilities. Workability of our model and methodology is illustrated using a case study including blood centres and hospitals surrounding Jamshedpur city. Our results shows that at-least 6 temporary blood facilities are required to satisfy the demand of blood during and post-disaster periods in Jamshedpur. The results also show that that past disaster conditions, response time and convenience for access are the most important factors for locating the temporary blood facilities during and post-disaster periods