Amino acid position 11 of HLA-DRß1 is a major determinant of chromosome 6p association with ulcerative colitis.

The major histocompatibility complex (MHC) on chromosome 6p is an established risk locus for ulcerative colitis (UC) and Crohn's disease (CD). We aimed to better define MHC association signals in UC and CD by combining data from dense single-nucleotide polymorphism (SNP) genotyping and from imputation of classical human leukocyte antigen (HLA) types, their constituent SNPs and corresponding amino acids in 562 UC, 611 CD and 1428 control subjects. Univariate and multivariate association analyses were performed, controlling for ancestry. In univariate analyses, absence of the rs9269955 C allele was strongly associated with risk for UC (P = 2.67 × 10(-13)). rs9269955 is a SNP in the codon for amino acid position 11 of HLA-DRß1, located in the P6 pocket of the HLA-DR antigen binding cleft. This amino acid position was also the most significantly UC-associated amino acid in omnibus tests (P = 2.68 × 10(-13)). Multivariate modeling identified rs9269955-C and 13 other variants in best predicting UC vs control status. In contrast, there was only suggestive association evidence between the MHC and CD. Taken together, these data demonstrate that variation at HLA-DRß1, amino acid 11 in the P6 pocket of the HLA-DR complex antigen binding cleft is a major determinant of chromosome 6p association with UC.

Medical Management of Biological Casualties Handbook - 5th edition

It provides information and guidelines for the prophylaxis and management of biological casualties, i.e., diseases or injuries caused by bacteria, viruses, and toxins which might be used as biological weapons, and for detection, personal protection, and decontamination. Document in PDF format; Acrobat Reader required.

Structure of the highly conserved HERC2 gene and of multiple partially duplicated paralogs in human.

Recombination between chromosome-specific low-copy repeats (duplicons) is an underlying mechanism for several genetic disorders. Recently, a chromosome 15 duplicon was discovered in the common breakpoint regions of Prader-Willi and Angelman syndrome deletions. We identified previously the large HERC2 transcript as an ancestral gene in this duplicon, with approximately 11 HERC2-containing duplicons, and demonstrated that recessive mutations in mouse Herc2 lead to a developmental syndrome, juvenile development and fertility 2 (jdf2). We have now constructed and sequenced a genomic contig of HERC2, revealing a total of 93 exons spanning approximately 250 kb and a CpG island promoter. A processed ribosomal protein L41 pseudogene occurs in intron 2 of HERC2, and putative VNTRs occur in intron 70 (28 copies, approximately 76-bp repeat) and 3' exon 40 through intron 40 (6 copies, approximately 62-bp repeat). Sequence comparisons show that HERC2-containing duplicons have undergone several deletion, inversion, and dispersion events to form complex duplicons in 15q11, 15q13, and 16p11. To further understand the developmental role of HERC2, a highly conserved Drosophila ortholog was characterized, with 70% amino acid sequence identity to human HERC2 over the carboxy-terminal 743 residues. Combined, these studies provide significant insights into the structure of complex duplicons and into the evolutionary pathways of formation, dispersal, and genomic instability of duplicons. Our results establish that some genes not only have a protein coding function but can also play a structural role in the genome.

Respiratory syncytial virus induces interleukin-10 by human alveolar macrophages. Suppression of early cytokine production and implications for incomplete immunity.

Respiratory syncytial virus (RSV) causes repeated infections thought to be due to an ineffective immune response. We examined the hypothesis that incomplete immunity may result, in part, from RSV-infected alveolar macrophage production of IL-10 which can interfere with the production of immunoregulatory cytokines. We also assessed whether RSV induced the expression of the 2',5' oligoadenylate (2-5A)-dependent RNase L, an endoribonuclease involved in the antiviral activities of interferons. Human alveolar macrophages were exposed to medium (uninfected control), RSV, LPS, and RSV + LPS then were assessed for expression of the cytokines TNF-alpha, IL-1 beta, IL-8, IL-10, as well as 2-5A-dependent RNase L. LPS up-regulated the expression of protein and mRNA for all cytokines. RSV stimulated the protein levels of TNF-alpha, did not alter IL-1 beta, and decreased IL-8. RSV markedly stimulated protein expression of IL-10 and 2-5A-dependent RNase L. RSV had minor effects on the steady state mRNA levels of TNF-alpha, IL-1 beta, and IL-8, yet potently induced IL-10. Cells costimulated with RSV + LPS demonstrated reduced protein and mRNA levels of TNF-alpha, IL-1 beta, IL-8 but synergistically increased IL-10 levels compared to RSV- or LPS-activated cells. Kinetic analysis indicated that RSV induced a delayed and sustained increase in IL-10 transcripts. Furthermore, RSV-infected alveolar macrophage supernatants suppressed IL-1 beta and IL-8 production by LPS-stimulated alveolar macrophages as did recombinant IL-10. Anti-IL-10 neutralized these effects. These studies indicate that RSV is capable of suppressing production of early immunoregulatory cytokines through induction of IL-10 perhaps mediated by 2-5A-dependent RNase L (or other endoribonucleases) accounting for the ineffective immune response to this virus.

Respiratory syncytial virus replication in human lung epithelial cells: inhibition by tumor necrosis factor alpha and interferon beta.

Respiratory syncytial virus (RSV) is the major pathogen causing severe lung disease in children. RSV initially replicates efficiently in the respiratory tract but becomes undetectable by 7 to 21 d after infection in normal children, suggesting that intrinsic cellular mechanisms, as yet undefined, may restrict virus replication. To provide an in vitro model to examine mechanisms that restrict RSV replication, three human lung epithelial cell lines were exposed to RSV in vitro and virus replication proceeded in a dose- and time-dependent manner, although less efficiently than the highly permissive CV-1 cell line (monkey kidney epithelial cell). Tumor necrosis factor alpha (TNF alpha) and/or interferon beta (IFN beta) markedly inhibited RSV replication in a dose- and time-dependent manner. TNF alpha combined with IFN beta essentially aborted RSV replication in A549 epithelial cells. TNF alpha and/or IFN beta did not induce cell membrane damage, cause cell lysis, or inhibit cellular protein synthesis. RSV-infected human alveolar macrophages, which produce TNF alpha, failed to productively infect lung epithelial cells in co-culture. Together these studies suggest that endogenous TNF alpha coupled with exogenous IFN beta could restrict RSV replication in lung epithelium.

Epithelial interleukin-11. Regulation by cytokines, respiratory syncytial virus, and retinoic acid.

Interleukin-11 (IL-11) is a pleiotropic cytokine with effects that overlap with IL-6. To determine if IL-11 is produced by epithelial cells, we determined whether human alveolar A549 cells and airway 9HTE cells produce IL-11. We also determined whether retinoic acid (RA) altered this IL-11 production. Unstimulated cells produced low levels of IL-11, while IL-1, transforming growth factor (TGF-beta 1), and respiratory syncytial virus (RSV) stimulated IL-11 protein production and mRNA accumulation in a time- and dose-dependent fashion. IL-1 and TGF-beta 1 also interacted in a synergistic, and presumedly transcriptional, fashion since they augmented A549 cell IL-11 protein production and mRNA accumulation without altering IL-11 mRNA half-life. In contrast, IL-4 only weakly stimulated, and IL-7, hepatocyte growth factor, and herpes simplex virus Type 2 did not stimulate, IL-11 production. RA did not alter the IL-11 production of unstimulated or RSV infected cells. It did, however, inhibit rIL-1-stimulated and synergistically augment TGF-beta-stimulated IL-11 production. Thus, IL-1, TGF-beta, and RSV stimulate epithelial-like cell IL-11 production, and RA regulates these inductive processes in a stimulus-specific fashion.

Restricted replication of respiratory syncytial virus in human alveolar macrophages.

The cellular factors that regulate infection and replication of respiratory syncytial virus (RSV) in human alveolar macrophages were examined. RSV-exposed alveolar macrophages demonstrated a time-dependent expression of viral glycoproteins, maximal by 24 h post-infection resulting in infection of approx. 38% of the cells. Essentially all (33%) of these freshly isolated alveolar macrophages replicated RSV as shown by infectious centre assays. This RSV-permissive subpopulation of alveolar macrophages consisted primarily of major histocompatibility class II-expressing cells as determined by fluorescence-activated cell sorting. Re-infection of alveolar macrophages did not significantly alter the number of cells infected or capable of replicating RSV. However, in vitro differentiation of alveolar macrophages prior to infection resulted in a significant (P < 0.05), time-dependent decrease (approx. sevenfold) in the number of cells that replicated virus. The mechanism by which cellular differentiation restricted RSV replication is unknown. Production of defective interfering particles did not account for this decrease. Alveolar macrophages infected with RSV produce a variety of cytokines potentially contributing to this restricted viral replication. Pretreatment with several of these cytokines did not affect viral infection or replication. However, tumour necrosis factor (TNF alpha) significantly (P < 0.05) decreased viral replication but only by 30 to 60%. Thus RSV replication is reduced by in vitro differentiation of alveolar macrophages and, to a lesser degree, by pretreatment with TNF.

Stability of local anesthetics in the dental cartridge.

Recent manufacturer recalls of local anesthetics have emphasized the problems with storage stability. This article reviews the principles of drug stability, mechanisms of degradation of commonly used vasoconstrictors, research on the stability of commercially produced local anesthetic preparations, and possible effects of the container-closure system. The review concludes with a list of practical and clinical suggestions on how to minimize storage stability problems with dental local anesthetics.

Proteoglycan structural changes in human rheumatoid articular cartilage.

Human rheumatoid arthritic (RA) cartilage contains elevated levels of proteolytic enzymes in which the metalloproteases are believed to be the prime enzyme system involved in cartilage metabolism. We examined the effects of these enzymes and the serine proteases on endogenous proteoglycans (PGs) and newly synthesized PGs of seven RA cartilages. The data was further analyzed with regard to the therapy received by the patients prior to surgery. A structural heterogeneity among the PGs from RA cartilage was found, and two subsets were distinguished. While in the first subset more than 35% of the PGs were in aggregate form, no appreciable amount of PG aggregate was found in the second subset. Interestingly, in all but one specimen the subsets appeared to be a function of prior therapy received by the patients. In subset I patients had received prednisone and/or DMARD in addition to NSAIDs, while those from subset II had all received NSAIDs only, with one exception. Our findings also suggest that PG structure alterations could result from the action of already active and APMA-activated metalloproteases; these reduced the PG aggregation capability and caused extensive cleavage in the PG core protein. The serine proteases did not seem to play a major role. Moreover, when the endogenous latent metalloproteases were activated with APMA, high-density PGs (the A1D1 fraction) showed a reduction in their capacity to reaggregate, and in their hydrodynamic size. Using an immunological technique we demonstrated the presence, in subset I, of the hyaluronan binding region domain (HABR) of the core protein. For subset II this domain could not be found.(ABSTRACT TRUNCATED AT 250 WORDS)