920 resultados para site-specificity


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In the presence of 2-hydroxybiphenyl, the enhancer binding protein, HbpR, activates the sigma54-dependent P(hbpC) promoter and controls the initial steps of 2-hydroxybiphenyl degradation in Pseudomonas azelaica. In the activation process, an oligomeric HbpR complex of unknown subunit composition binds to an operator region containing two imperfect palindromic sequences. Here, the HbpR-DNA binding interactions were investigated by site-directed mutagenesis of the operator region and by DNA-binding assays using purified HbpR. Mutations that disrupted the twofold symmetry in the palindromes did not affect the binding affinity of HbpR, but various mutations along a 60 bp region, and also outside the direct palindromic sequences, decreased the binding affinity. Footprints of HbpR on mutant operator fragments showed that a partial loss of binding contacts occurs, suggesting that the binding of one HbpR 'protomer' in the oligomeric complex is impaired whilst leaving the other contacts intact. An HbpR variant, devoid of its N-terminal sensing A-domain, was unable to activate transcription from the hbpC promoter while maintaining protection of the operator DNA in footprints. Wild-type HbpR was unable to activate transcription from the hbpC promoter when delta A-HbpR was expressed in the same cell, suggesting the formation of (repressing) hetero-oligomers. This model implies that HbpR can self-associate on its operator DNA without effector recognition or ATP binding. Furthermore, our findings suggest that the N-terminal sensing domain of HbpR is needed to activate the central ATPase domain rather than to repress a constitutively active C domain, as is the case for the related regulatory protein XylR.

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BACKGROUND: In heart transplantation, antibody-mediated rejection (AMR) is diagnosed and graded on the basis of immunopathologic (C4d-CD68) and histopathologic criteria found on endomyocardial biopsies (EMB). Because some pathologic AMR (pAMR) grades may be associated with clinical AMR, and because humoral responses may be affected by the intensity of immunosuppression during the first posttransplantation year, we investigated the incidence and positive predictive values (PPV) of C4d-CD68 and pAMR grades for clinical AMR as a function of time. METHODS: All 564 EMB from 40 adult heart recipients were graded for pAMR during the first posttransplantation year. Clinical AMR was diagnosed by simultaneous occurrence of pAMR on EMB, donor specific antibodies and allograft dysfunction. RESULTS: One patient demonstrated clinical AMR at postoperative day 7 and one at 6 months (1-year incidence 5%). C4d-CD68 was found on 4,7% EMB with a "decrescendo" pattern over time (7% during the first 4 months vs. 1.2% during the last 8 months; P < 0.05). Histopathologic criteria of AMR occurred on 10.3% EMB with no particular time pattern. Only the infrequent (1.4%) pAMR2 grade (simultaneous histopathologic and immunopathologic markers) was predictive for clinical AMR, particularly after the initial postoperative period (first 4 months and last 8 months PPV = 33%-100%; P < 0.05). CONCLUSION: In the first posttransplantation year, AMR immunopathologic and histopathologic markers were relatively frequent, but only their simultaneous occurrence (pAMR2) was predictive of clinical AMR. Furthermore, posttransplantation time may modulate the occurrence of C4d-CD68 on EMB and thus the incidence of pAMR2 and its relevance to the diagnosis of clinical AMR.

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There has been increasing attention to the subgroups of mood disorders and their boundaries with other mental disorders, particularly psychoses. The goals of the present paper were (1) to assess the familial aggregation and co-aggregation patterns of the full spectrum of mood disorders (that is, bipolar, schizoaffective (SAF), major depression) based on contemporary diagnostic criteria; and (2) to evaluate the familial specificity of the major subgroups of mood disorders, including psychotic, manic and major depressive episodes (MDEs). The sample included 293 patients with a lifetime diagnosis of SAF disorder, bipolar disorder and major depressive disorder (MDD), 110 orthopedic controls, and 1734 adult first-degree relatives. The diagnostic assignment was based on all available information, including direct diagnostic interviews, family history reports and medical records. Our findings revealed specificity of the familial aggregation of psychosis (odds ratio (OR)=2.9, confidence interval (CI): 1.1-7.7), mania (OR=6.4, CI: 2.2-18.7) and MDEs (OR=2.0, CI: 1.5-2.7) but not hypomania (OR=1.3, CI: 0.5-3.6). There was no evidence for cross-transmission of mania and MDEs (OR=.7, CI:.5-1.1), psychosis and mania (OR=1.0, CI:.4-2.7) or psychosis and MDEs (OR=1.0, CI:.7-1.4). The strong familial specificity of psychotic, manic and MDEs in this largest controlled contemporary family study challenges the growing assertion that the major types of mood disorders are manifestations of a common underlying diathesis.

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Efficient immune attack of malignant disease requires the concerted action of both CD8+ CTL and CD4+ Th cells. We used human leukocyte antigen (HLA)-A*0201 (A2.1) transgenic mice, in which the mouse CD8 molecule cannot efficiently interact with the alpha3 domain of A2.1, to generate a high-affinity, CD8-independent T cell receptor (TCR) specific for a commonly expressed, tumor-associated cytotoxic T lymphocyte (CTL) epitope derived from the human p53 tumor suppressor protein. Retroviral expression of this CD8-independent, p53-specific TCR into human T cells imparted the CD8+ T lymphocytes with broad tumor-specific CTL activity and turned CD4+ T cells into potent tumor-reactive, p53A2.1-specific Th cells. Both T cell subsets were cooperative and interacted synergistically with dendritic cell intermediates and tumor targets. The intentional redirection of both CD4+ Th cells and CD8+ CTL by the same high-affinity, CD8-independent, tumor-specific TCR could provide the basis for novel broad-spectrum cancer immunotherapeutics.

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Introduction: L'unité d'Assistance Pharmaceutique de la Pharmacie des HUG fonctionne comme centre d'information sur les médicaments et gère des informations mises à disposition sur le web. Celles-ci sont destinées prioritairement au personnel soignant des HUG et accessibles sur le site intranet/Internet (http://www.hcuge.ch/Pharmacie), mis en service en 1998. L'objectif de ce travail était d'évaluer la qualité de l'information du site intranet/Internet et d'y apporter les améliorations nécessaires. Méthode: Le site intranet/Internet de la pharmacie des HUG a été évalué en automne 2004 à l'aide de 2 outils : NetScoring : grille d'évaluation de la qualité de l'information de santé sur Internet (http://www.chu-rouen.fr/netscoring/). Elle comporte 49 critères répartis en 8 catégories. Chaque critère est noté sur une échelle de 5 occurrences puis pondéré selon son importance (multiplication par 3 si le critère est essentiel, par 2 s'il est important ou par 1 s'il est mineur). Analyse AMDEC : méthode permettant de séquencer un processus et d'en Analyser les Modes de Défaillance, leur Effet et leur Criticité (Qual Saf Health Care 2005 :14(2);93-98). Un score est attribué à chaque mode de défaillance identifié en terme de fréquence, de sévérité et de détectabilité. La multiplication des 3 scores fournit un résultat global de criticité (indice de criticité IC, max. 810), permettant de hiérarchiser les risques. Résultats: Etat des lieux NetScoring : La qualité globale du site intranet/Internet était bonne (202 pts/312). Les points forts concernaient la pertinence et l'utilité du site, la qualité du contenu, du moteur de recherche et du design, la rapidité de chargement du site, la sélection des liens externes proposés et le respect du secret médical. Les faiblesses résidaient dans l'absence de politique de mise à jour régulière, d'annotation systématique de l'état d'actualisation des documents, d'un comité éditorial et scientifique, de mots-clés en anglais et d'une liste permettant l'identification des auteurs. Analyse AMDEC : Quatre catégories (création du document, conversion, structure du site et publication du document) et 19 modes de défaillances ont été caractérisés. Trois modes de défaillance étaient associés à un IC important: erreurs lors de la création d'un document (IC 256), information inadéquate car pratique non validée ou recommandation non généralisable (IC 147) et absence de relecture après la conversion du document en format publiable (ex : PDF) (IC 144). Mesures correctives: Une procédure standard (SOP) a été élaborée pour la gestion du site intranet/Internet. Le format standard des informations (initiales de l'auteur, dates de création et de mise à jour, logo de la pharmacie), la validation et la politique de mise à jour des documents ainsi que la procédure d'archivage y sont clairement définis. Une fiche de suivi accompagnant chaque document a été créée pour la traçabilité de toutes les modifications effectuées et la fréquence de révision à respecter. Discussion et conclusion Cette étude a permis de déterminer et de quantifier les points critiques à améliorer sur le site intranet/Internet de la Pharmacie des HUG. Les mesures correctives entreprises doivent permettre d'améliorer les principales faiblesses et défaillances mises en évidence. La mise en place d'un comité éditorial et scientifique devra être évaluée à l'avenir. Le NetScoring et l'analyse AMDEC sont des outils utiles pour l'évaluation et l'amélioration continue de la qualité d'un site Internet, sous réserve d'une interprétation critique des résultats obtenus avant la mise en place de mesures correctives. Malgré une approche totalement différente, ces outils ont permis de mettre en évidence des lacunes similaires.

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Positive selection is widely estimated from protein coding sequence alignments by the nonsynonymous-to-synonymous ratio omega. Increasingly elaborate codon models are used in a likelihood framework for this estimation. Although there is widespread concern about the robustness of the estimation of the omega ratio, more efforts are needed to estimate this robustness, especially in the context of complex models. Here, we focused on the branch-site codon model. We investigated its robustness on a large set of simulated data. First, we investigated the impact of sequence divergence. We found evidence of underestimation of the synonymous substitution rate for values as small as 0.5, with a slight increase in false positives for the branch-site test. When dS increases further, underestimation of dS is worse, but false positives decrease. Interestingly, the detection of true positives follows a similar distribution, with a maximum for intermediary values of dS. Thus, high dS is more of a concern for a loss of power (false negatives) than for false positives of the test. Second, we investigated the impact of GC content. We showed that there is no significant difference of false positives between high GC (up to similar to 80%) and low GC (similar to 30%) genes. Moreover, neither shifts of GC content on a specific branch nor major shifts in GC along the gene sequence generate many false positives. Our results confirm that the branch-site is a very conservative test.

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The anaerobic transcriptional regulator ANR induces the arginine deiminase and denitrification pathways in Pseudomonas aeruginosa during oxygen limitation. The homologous activator FNR of Escherichia coli, when introduced into an anr mutant of P. aeruginosa, could functionally replace ANR for anaerobic growth on nitrate but not for anaerobic induction of arginine deiminase. In an FNR-positive E. coli strain, the ANR-dependent promoter of the arcDABC operon, which encodes the enzymes of the arginine deiminase pathway, was not expressed. To analyse systematically these distinct induction patterns, a lacZ promoter-probe, broad-host-range plasmid containing various -40 regions (the ANR/FNR recognition sequences) and -10 promoter sequences was constructed. These constructs were tested in P. aeruginosa and in E. coli expressing either ANR or FNR. In conjunction with the consensus -10 hexamer of E. coli sigma 70 RNA polymerase (TATAAT), the consensus FNR site (TTGAT ..... ATCAA) was recognized efficiently by ANR and FNR in both hosts. By contrast, when promoters contained the Arc box (TTGAC .... ATCAG), which is found in the arcDABC promoter, or a symmetrical mutant FNR site (CTGAT .... ATCAG), ANR was a more effective activator than was FNR. Conversely, an extended 22 bp, fully symmetrical FNR site allowed better activation with FNR than with ANR. Combination of the arc promoter -10 sequence (CCTAAT) with the Arc box or the consensus FNR site resulted in good ANR-dependent expression in P. aeruginosa but gave practically no expression in E. coli, suggesting that RNA polymerase of P. aeruginosa differs from the E. coli enzyme in -10 recognition specificity. In conclusion, ANR and FNR are able to activate the RNA polymerases of P. aeruginosa and E. coli when the -40 and -10 promoter elements ae identical or close to the E. coli consensus sequences.

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Immunological pressure encountered by protozoan parasites drives the selection of strategies to modulate or avoid the immune responses of their hosts. Here we show that the parasite Entamoeba histolytica has evolved a chemokine that mimics the sequence, structure, and function of the human cytokine HsEMAPII (Homo sapiens endothelial monocyte activating polypeptide II). This Entamoeba EMAPII-like polypeptide (EELP) is translated as a domain attached to two different aminoacyl-tRNA synthetases (aaRS) that are overexpressed when parasites are exposed to inflammatory signals. EELP is dispensable for the tRNA aminoacylation activity of the enzymes that harbor it, and it is cleaved from them by Entamoeba proteases to generate a standalone cytokine. Isolated EELP acts as a chemoattractant for human cells, but its cell specificity is different from that of HsEMAPII. We show that cell specificity differences between HsEMAPII and EELP can be swapped by site directed mutagenesis of only two residues in the cytokines' signal sequence. Thus, Entamoeba has evolved a functional mimic of an aaRS-associated human cytokine with modified cell specificity.

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The United States Environmental Protection Agency (EPA) has requested the Iowa Department of Public Health (IDPH) to evaluate the health impacts associated with exposure to contaminants of concern that have been found at the former Chamberlain Manufacturing Site. The EPA has been involved in the investigation and remediation of the Former Chamberlain Manufacturing Site since 2005. As part of these investigative activities, on-site soil sampling and both on-and off-site groundwater sampling has been completed. In addition, sub-slab soil gas, indoor air, and ambient air sampling at properties located near the Former Chamberlain Manufacturing Site has been completed. This health consultation addresses potential health risks to the public from exposure to the soil, groundwater and potential vapors within homes or buildings at or near the Former Chamberlain Manufacturing Site. The information in this health consultation was current at the time of writing. Data that emerges later could alter this document’s conclusions and recommendations.

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The Iowa Department of Natural Resources (IDNR) has requested that the Iowa Department of Public Health (IDPH) complete an update of the health consultation for the Hills, Iowa Perchlorate Groundwater Contamination Site that was originally completed in June 2004. In this updated health consultation, the IDPH will: 1) summarize background information on this site, 2) summarize the progress of work that has been completed regarding the site, 3) summarize the environmental data that has been collected, 4) summarize toxicological information and regulatory information regarding perchlorate, and 5) provide an update to any conclusions and recommendations from the Iowa Department of Public Health. The Iowa Department of Public Health’s priority is to ensure the Hills community has the best information possible to safeguard its health and the IDNR has the best information to guide its activities. That information is included in the following paragraphs.

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The Prairie Trail Development Area is located in the southern portion of Ankeny, Iowa. This development area is located in an area that was formally occupied by the Des Moines Ordnance Plant. The Des Moines Ordnance Plant was constructed for the production and testing of small arms munitions for use during World War II. The Landfill and Lagoon Complex was utilized for disposal of wastes from the ordnance plant and also from various entities that utilized the site property until 1991. The United States Environmental Protection Agency (EPA) is verseeing the cleanup of the Landfill and Lagoon Complex. A portion of the remainder of the site property had been used for burning of scrap explosives, the storage and disposal of chemicals, a disposal pond, testing of products, and various munitions manufacturing activities. The Iowa Department of Natural Resources (IDNR) is overseeing the cleanup of this remaining portion of the site property. The Iowa Department of Public Health has been contacted by residents within the Prairie Trail Development Area and by individuals that have an interest in relocating to the Prairie Trail Development Area. These residents are concerned with any environmental contamination that will be left after site remedial activities are completed. These residents want to know if any remaining environmental contamination will adversely impact their health or the health of their families.

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The U.S. Environmental Protection Agency (EPA) is completing a third five-year review of the E.I. du Pont de Nemours & Co., Inc., County Road X-23 Superfund site in Lee County, Iowa. The site is also known as the Baier and McCarl subsites. The EPA is inviting public comment on whether the current site remedy continues to be protective of public health and the environment. The Iowa Department of Public Health in cooperation with the Agency for Toxic Substances and Disease Registry (ATSDR) prepared this health consultation to review the current status of the Baier and McCarl subsites and to provide an evaluation of the public health status of these subsites. The information in this health consultation was current at the time of writing. Data that emerges later could alter this docum ent’s conclusions and recommendations.

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This letter has been prepared as a consultation to EPA regarding the first five-year review of the Mason City Coal Gasification Plant Site, located in Mason City, Iowa to provide an evaluation of the public health status of the site.

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This letter has been prepared as a consultation to EPA regarding the third five year review of the Northwestern States Portland Cement Company Site, located North of Mason City, Iowa in Cerro Gordo County to provide an evaluation of the public health status of the site.

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This letter has been prepared as a consultation to evaluate human health impacts from residual contamination left from the former operation of a salvage yard on this property that is planned to be utilized by the North Iowa Humane Society located in Fort Dodge, Iowa. The Iowa Department of Public Health’s priority is to ensure the Fort Dodge community has the best information possible to safeguard its health. That information is included in following paragraphs.