1,115 research outputs found

    Development and Application of Synthetic Affinity Ligands for the Purification of Ferritin-Based Influenza Antigens

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    A recently developed novel recombinant influenza antigen vaccine has shown great success in preclinical studies in ferrets and mice. It provides broader protection, and is efficient to manufacture compared to the conventional trivalent influenza vaccines (TIV). Each strain of the recombinant antigen has a constant self-assembled bacterial ferritin core which, if used as a target for affinity chromatography, could lead to a universal purification method. Ferritin in silico models were used to explore potential target binding sites against ligands synthesized by the four-component Ugi reaction. Two ligands, SJ047 and SJ055, were synthesized in solution, characterized by 1H, 13C, and 2D NMR spectroscopy, and subsequently immobilized on the PEG-functionalized beads. Ligands SJ047 and SJ055 displayed apparent Kd values of 2.04 × 10–7 M and 1.91 × 10–8 M, respectively, against the ferritin. SJ047 and SJ055-functionalized resins were able to purify hemagglutinin (New Caledonia)-ferritin expressed in a crude Human Embryonic Kidney (HEK) cell supernatant in a single step to a purity of 85 ± 0.5% (97 ± 1% yield) and 87.5 ± 0.5% (95.5 ± 1.5% yield), respectively. Additionally, SJ047 and SJ055-functionalized resins purified the recombinant antigens when spiked at known concentrations into HEK supernatants. All three strains, hemagglutinin (New Caledonia)-ferritin, hemagglutinin (California)-ferritin, and hemagglutinin (Singapore)-ferritin were purified, thereby offering an ideal alternate platform for affinity chromatography. Following elution from the affinity adsorbents, absorbance at 350 nm showed that there was no aggregation of the recombinant antigens and dynamic light scattering studies further confirmed the structural integrity of the recombinant antigen. The use of Ugi ligands coupled to a PEG-spacer arm to target the ferritin core of the strain is entirely novel and provides an efficient purification of these recombinant antigens. This approach represents a potentially universal method to purify any ferritin-based vaccine

    Sandpile model on an optimized scale-free network on Euclidean space

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    Deterministic sandpile models are studied on a cost optimized Barab\'asi-Albert (BA) scale-free network whose nodes are the sites of a square lattice. For the optimized BA network, the sandpile model has the same critical behaviour as the BTW sandpile, whereas for the un-optimized BA network the critical behaviour is mean-field like.Comment: Five pages, four figure

    Abdominal surgical site infections: incidence and risk factors at an Iranian teaching hospital

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    BACKGROUND: Abdominal surgical site infections are among the most common complications of inpatient admissions and have serious consequences for outcomes and costs. Different risk factors may be involved, including age, sex, nutrition and immunity, prophylactic antibiotics, operation type and duration, type of shaving, and secondary infections. This study aimed to determine the risk factors affecting abdominal surgical site infections and their incidence at Imam Khomeini, a major referral teaching hospital in Iran. METHODS: Patients (n = 802) who had undergone abdominal surgery were studied and the relationships among variables were analyzed by Student's t and Chi-square tests. The subjects were followed for 30 days and by a 20-item questionnaire. Data were collected through pre- and post-operative examinations and telephone follow-ups. RESULTS: Of the 802 patients, 139 suffered from SSI (17.4%). In 40.8% of the cases, the wound was dirty infected. The average age for the patients was 46.7 years. The operations were elective in 75.7% of the cases and 24.7% were urgent. The average duration of the operation was 2.24 hours, the average duration of pre-operative hospital stay 4.31 days and the average length of (pre- and post-operation) hospital stay 11.2 days. Three quarters of the cases were shaved 12 hours before the operation. The increased operation time, increased bed stay, electivity of the operation, septicity of the wound, type of incision, the administration of prophylactic antibiotic, type of operation, background disease, and the increased time lapse between shaving and operation all significantly associated with SSI with a p-value less than 0.001. CONCLUSION: In view of the high rate of SSI reported here (17.4% compared with the 14% quoted in literature), this study suggests that by reducing the average operation time to less than 2 hours, the average preoperative stay to 4 days and the overall stay to less than 11 days, and approximating the timing of shaving to the operation and substituting cefazolin for cefaluthin when prophylactic antibiotic is to be administered, the SSI may be reduced to a more acceptable level

    International Veterinary Epilepsy Task Force consensus proposal: Medical treatment of canine epilepsy in Europe

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    In Europe, the number of antiepileptic drugs (AEDs) licensed for dogs has grown considerably over the last years. Nevertheless, the same questions remain, which include, 1) when to start treatment, 2) which drug is best used initially, 3) which adjunctive AED can be advised if treatment with the initial drug is unsatisfactory, and 4) when treatment changes should be considered. In this consensus proposal, an overview is given on the aim of AED treatment, when to start long-term treatment in canine epilepsy and which veterinary AEDs are currently in use for dogs. The consensus proposal for drug treatment protocols, 1) is based on current published evidence-based literature, 2) considers the current legal framework of the cascade regulation for the prescription of veterinary drugs in Europe, and 3) reflects the authors’ experience. With this paper it is aimed to provide a consensus for the management of canine idiopathic epilepsy. Furthermore, for the management of structural epilepsy AEDs are inevitable in addition to treating the underlying cause, if possible

    Surface and Temporal Biosignatures

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    Recent discoveries of potentially habitable exoplanets have ignited the prospect of spectroscopic investigations of exoplanet surfaces and atmospheres for signs of life. This chapter provides an overview of potential surface and temporal exoplanet biosignatures, reviewing Earth analogues and proposed applications based on observations and models. The vegetation red-edge (VRE) remains the most well-studied surface biosignature. Extensions of the VRE, spectral "edges" produced in part by photosynthetic or nonphotosynthetic pigments, may likewise present potential evidence of life. Polarization signatures have the capacity to discriminate between biotic and abiotic "edge" features in the face of false positives from band-gap generating material. Temporal biosignatures -- modulations in measurable quantities such as gas abundances (e.g., CO2), surface features, or emission of light (e.g., fluorescence, bioluminescence) that can be directly linked to the actions of a biosphere -- are in general less well studied than surface or gaseous biosignatures. However, remote observations of Earth's biosphere nonetheless provide proofs of concept for these techniques and are reviewed here. Surface and temporal biosignatures provide complementary information to gaseous biosignatures, and while likely more challenging to observe, would contribute information inaccessible from study of the time-averaged atmospheric composition alone.Comment: 26 pages, 9 figures, review to appear in Handbook of Exoplanets. Fixed figure conversion error

    Adenomyoma of the Ileum Leading to Intussusception

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    Adenomyoma of the ileum is a rare condition. A 68-year-old Japanese man presented with nausea and distension of the abdomen. Enhanced computed tomography of his abdomen revealed wall thickening in the ileum and dilation of the proximal small intestine. Open laparotomy was performed to find the cause of the patient's small bowel obstruction, and a tumor was found in the ileum, which had resulted in intussusception. The tumor and 20 cm of the adjacent ileum were resected. The resected specimen displayed a macroscopic appearance suggestive of a submucosal tumor. Histopathological evaluation showed duct cell proliferation and bundles of smooth muscle cells from the mucosa to the serosa, leading to a diagnosis of adenomyoma. Immunohistochemical examination found that cytokeratin 7 and carbohydrate antigen 19-9 were expressed in the duct epithelia. We report a rare case of ileal adenomyoma leading to intussusception in an adult and present the immunohistochemical evaluation of the adenomyoma
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