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Particular Pathogen (particular + pathogen)
Selected AbstractsPathogen safety of manufacturing processes for biological products: special emphasis on KOGENATE® BayerHAEMOPHILIA, Issue 2002D. C. Lee Summary., Manufacturers of human therapeutic proteins derived from biological sources continuously strive to improve the pathogen safety profiles of these products. Efforts to improve pathogen safety margins for these biological products are directed towards several areas within the manufacturing processes including: (a) sourcing and screening of raw materials (b) determining the potential for manufacturing processes to reduce pathogen titres, and (c) incorporating methods designed specifically to remove or inactivate contaminating pathogens. Methods that could potentially reduce pathogen titres are a major focus for many manufacturers. In general, these methods are grouped into two categories, pathogen clearance and pathogen inactivation. Assessments are performed on small-scale, laboratory simulations of the manufacturing process of interest that are spiked with a known amount of a selected pathogen. These studies provide estimates of the potential for a process step to remove or inactivate a particular pathogen. There are several pathogen clearance/inactivation methods that are inherent in manufacturing processes, however, some methods are intentionally incorporated into manufacturing for the sole purpose of reducing putative pathogen titres. Not only are well-known pathogens such as viruses targeted, but also suspected pathogens such as those associated with the transmissible spongiform encephalopathies (TSEs). The production processes for the isolation of several biological products, including recombinant KOGENATE® Bayer (Kogenate®FS), have been evaluated for the ability to reduce pathogen titres and/or have been designed to incorporate methods for reducing potential pathogen safety risks. Several processing steps with the potential to reduce pathogen titres have been identified. [source] The potential for Toll-like receptors to collaborate with other innate immune receptorsIMMUNOLOGY, Issue 4 2004Subhankar Mukhopadhyay Summary Cells of the innate immune system express a large repertoire of germ-line encoded cell-surface glycoprotein receptors including Toll-like receptors (TLRs). TLRs recognize conserved motifs on microbes and induce inflammatory signals. Evidence suggests that individual members of the TLR family or other non-TLR surface antigens either physically or functionally interact with each other and cumulative effects of these interactions instruct the nature and outcome of the immune response to a particular pathogen. [source] Inflammatory bowel disease: Epidemiology, pathogenesis, and therapeutic opportunitiesINFLAMMATORY BOWEL DISEASES, Issue 5 2006Stephen B Hanauer MD Abstract Ulcerative colitis (UC) and Crohn's disease (CD), the primary constituents of inflammatory bowel disease (IBD), are precipitated by a complex interaction of environmental, genetic, and immunoregulatory factors. Higher rates of IBD are seen in northern, industrialized countries, with greater prevalence among Caucasians and Ashkenazic Jews. Racial gaps are closing, indicating that environmental factors may play a role. IBD is multigenic, with the most clearly established genetic link between certain NOD2 variants and CD. Regardless of the underlying genetic predisposition, a growing body of data implicates a dysfunctional mucosal immune response to commensal bacteria in the pathogenesis of IBD, especially CD. Possible triggers include a chronic inflammatory response precipitated by infection with a particular pathogen or virus or a defective mucosal barrier. The characteristic inflammatory response begins with an infiltration of neutrophils and macrophages, which then release chemokines and cytokines. These in turn exacerbate the dysfunctional immune response and activate either TH1 or TH2 cells in the gut mucosa, respectively associated with CD and, less conclusively, with UC. Elucidation of immunological and genetic factors indicate multiple points at which the inflammatory cascade may be interrupted, yielding the possibility of precise, targeted therapies for IBD. [source] Genome dynamics in major bacterial pathogensFEMS MICROBIOLOGY REVIEWS, Issue 3 2009Ole Herman Ambur Abstract Pathogenic bacteria continuously encounter multiple forms of stress in their hostile environments, which leads to DNA damage. With the new insight into biology offered by genome sequences, the elucidation of the gene content encoding proteins provides clues toward understanding the microbial lifestyle related to habitat and niche. Campylobacter jejuni, Haemophilus influenzae, Helicobacter pylori, Mycobacterium tuberculosis, the pathogenic Neisseria, Streptococcus pneumoniae, Streptococcus pyogenes and Staphylococcus aureus are major human pathogens causing detrimental morbidity and mortality at a global scale. An algorithm for the clustering of orthologs was established in order to identify whether orthologs of selected genes were present or absent in the genomes of the pathogenic bacteria under study. Based on the known genes for the various functions and their orthologs in selected pathogenic bacteria, an overview of the presence of the different types of genes was created. In this context, we focus on selected processes enabling genome dynamics in these particular pathogens, namely DNA repair, recombination and horizontal gene transfer. An understanding of the precise molecular functions of the enzymes participating in DNA metabolism and their importance in the maintenance of bacterial genome integrity has also, in recent years, indicated a future role for these enzymes as targets for therapeutic intervention. [source] Between-year variation of MHC allele frequencies in great reed warblers: selection or drift?JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 3 2004H. Westerdahl Abstract The major histocompatibility complex (MHC) genes are extremely polymorphic and this variation is assumed to be maintained by balancing selection. Cyclic interactions between pathogens and their hosts could generate such selection, and specific MHC alleles or heterozygosity at certain MHC loci have been shown to confer resistance against particular pathogens. Here we compare the temporal variation in allele frequencies of 23 MHC class I alleles with that of 23 neutral microsatellite markers in adult great reed warblers (a passerine bird) in nine successive cohorts. Overall, the MHC alleles showed a significantly higher variation in allele frequencies between cohorts than the microsatellite alleles, using a multi-variate genetic analysis (amova). The frequency of two specific MHC alleles, A3e (P = 0.046) and B4b (P = 0.0018), varied more between cohorts than expected from random, whereas none of the microsatellite alleles showed fluctuations exceeding the expectation from stochastic variation. These results imply that the variation in MHC allele frequencies between cohorts is not a result of demographic events, but rather an effect of selection favouring different MHC alleles in different years. [source] | |||||||||||||