• Proctor Grimes posted an update 1 year, 6 months ago

    HEK293 cell lines are used for the production of recombinant proteins, virus-like particles and viral vectors. see more Recent work has generated molecular (systems level) characterisation of HEK293 variants that has enabled re-engineering of the cells towards enhanced use for manufacture-scale production of recombinant biopharmaceuticals (assessment of ‘safe harbours’ for gene insertion, engineering of new variants for stable, amplifiable expression). In parallel, there have been notable advances in the bioprocessing conditions (suspension adaptation, development of defined serum-free media) that offer the potential for large-scale manufacture, a feature especially important in the drive to produce viral vectors at large-scale and at commercially viable costs for gene therapy. The combination of cell-based and bioprocess-based modification of existing HEK293 cell processes, frequently informed by understandings transferred from developments with Chinese hamster ovary cell lines, seems destined to place the HEK293 cell systems firmly as a critical platform for production of future biologically based therapeutics.Multiple outbreaks of Mycoplasma bovis (M. bovis) have been reported in North American bison (Bison bison) in Alberta, Manitoba, Saskatchewan, Nebraska, New Mexico, Montana, North Dakota, and Kansas. M. bovis is mainly spread through direct contact and disseminated via animal movements thus, reliable genotyping is crucial for epidemiological investigations. The present study describes the genotyping of sixty-one M. bovis strains from cattle and bison isolated from different provinces of Canada by multi locus sequence typing (MLST), and multiple-locus variable-number tandem repeat analysis (MLVA). The sixty M. bovis clinical isolates together with the reference strain PG45 were divided into ten sequence types by MLST. Three novel sequence types were identified. Two isolates, one from cattle and one from bison shared the same sequence type, whereas one strain had the same sequence type as PG45. The cattle isolates could be further subdivided in Clade A with two subclades and bison isolates were grouped in Clade B with two subclades. With the exception of one animal, isolates originating from the same animal had the same sequence type. The sixty-one isolates also formed three main clades with several subclades when analyzed by MLVA. A total of 20 VNTR (Variable number tandem repeats) types were distinguished, 8 in cattle and 12 in bison isolates. The results showed multiple sequence types and genotype populations of M. bovis in bison and cattle. The results may further help to understand the evolution of M. bovis and develop strain specific or sequence type diagnostic tools.Mycoplasma hyopneumoniae (MHP) is a concern both for pig well-being and producer economic viability. In the absence of fully protective health interventions, producers rely on controlled exposure to induce an immune response in pigs and minimize the clinical outcomes of MHP infection in pig populations. This study compared the effect of route of exposure on MHP infection, antibody response, clinical signs, and pathology. Six-week-old MHP-negative pigs (n = 78) were allocated to negative control (n = 6) or one of three MHP exposure routes intratracheal (n = 24, feeding catheter), intranasal (n = 24, atomization device), and aerosol (n = 24, fogger). Body weight, cough indices, and samples (serum, oral fluid, tracheal) were collected weekly through 49 days post-exposure (DPE). Intratrachal exposure produced the highest proportion (24/24) of MHP DNA-positive pigs on DPE 7, as well as earlier and higher serum antibody response. Intranasal and aerosol exposures resulted in infection with MHP DNA detected in tracheal samples from 18/24 and 21/24 pigs on DPE 7, respectively. Aerosol exposure had the least impact on weight gain (0.64 kg/day). No difference was observed among treatment groups in coughing and lung lesions at necropsy. While intratracheal inoculation and seeder animals are frequently used in swine production settings, intranasal or aerosol exposure are viable alternatives to achieve MHP infection. Regardless of the route, steps should be taken to verify the purity of the inoculum and, in the case of aerosol exposure, avert the unintended exposure of personnel and animals to other pathogens.Although RNA viruses exhibit extensive sequence diversity, the mutation rate must be limited to ensure protein functions that maintain the viral life cycle. Here, we compared the whole genome sequences of 150 isolates of classical swine fever virus (CSFV), obtained from a single epidemic that occurred in Japan during 2018-2020. After the detection of the first case, the disease spread among both farm pigs and wild boars and caused severe impact on the pig industry. To evaluate the diversification of the CSFV genome that eliminated mutations negatively affecting viral transmission, the substitution sets inherited by at least two isolates were separately evaluated as shared single nucleotide variants (SNVs) or shared single amino acid variants (SAVs). Comparisons of 12 protein-coding regions indicated that the percentages of SNVs and SAVs in the multifunctional nonstructural protein NS3 were the lowest, and shared SAVs were not detected in another nonstructural protein, NS4A. This demonstrated purifying negative selection suppressing changes in the protein sequences of NS3 and NS4A during virus transmission in the field. In contrast, a high possibility of nonsynonymous substitution among shared SNVs was detected only in genes encoding the secreted protein Erns and the nonstructural protein NS2, suggesting positive selection during the epidemic. Mapping of shared SAVs to the three-dimensional structure of Erns revealed that shared SAVs were not present in the substrate-binding sites but were instead localized to the peripheral region of the protein. These data will support efforts toward the development of diagnostic methods, recombinant vaccines, and antiviral agents targeting conserved and indispensable viral genes.The Moroccan TRIGA Mark II research reactor is to be equipped with a PGAA (Prompt Gamma Activation Analysis) facility to assist the country’s progression in socioeconomic areas such as the environment and geochemistry, agriculture, health, industry, cultural heritage, and human sciences. The requirements of the PGAA facility include a very high thermal to fast neutron flux ratio and a focused, thin beam. Supermirror neutron guides are generally used to meet such requirements due to their ability to reflect neutrons with a specific energy and scattering angle. This study was undertaken to determine a suitable neutron guide for achieving optimal performance for the PGAA facility, where such a determination needs to be made according to both the available space and the minimum performance needed for PGAA analysis. To better parameterize the neutron guide, a set of simulations were performed with the aim of establishing the best guide specifications. Three types of neutron guides were studied, namely straight, curved, and bender.

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