220 research outputs found

    Ensuring quality: a key consideration in scaling-up HIV-related point-of-care testing programs.

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    OBJECTIVE: The objective of the WHO/US President's Emergency Plan for AIDS Relief consultation was to discuss innovative strategies, offer guidance, and develop a comprehensive policy framework for implementing quality-assured HIV-related point-of-care testing (POCT). METHODS: The consultation was attended by representatives from international agencies (WHO, UNICEF, UNITAID, Clinton Health Access Initiative), United States Agency for International Development, Centers for Disease Control and Prevention/President's Emergency Plan for AIDS Relief Cooperative Agreement Partners, and experts from more than 25 countries, including policy makers, clinicians, laboratory experts, and program implementers. MAIN OUTCOMES: There was strong consensus among all participants that ensuring access to quality of POCT represents one of the key challenges for the success of HIV prevention, treatment, and care programs. The following four strategies were recommended: implement a newly proposed concept of a sustainable quality assurance cycle that includes careful planning; definition of goals and targets; timely implementation; continuous monitoring; improvements and adjustments, where necessary; and a detailed evaluation; the importance of supporting a cadre of workers [e.g. volunteer quality corps (Q-Corps)] with the role to ensure that the quality assurance cycle is followed and sustained; implementation of the new strategy should be seen as a step-wise process, supported by development of appropriate policies and tools; and joint partnership under the leadership of the ministries of health to ensure sustainability of implementing novel approaches. CONCLUSION: The outcomes of this consultation have been well received by program implementers in the field. The recommendations also laid the groundwork for developing key policy and quality documents for the implementation of HIV-related POCT

    Fibrates downregulate apolipoprotein C-III expression independent of induction of peroxisomal acyl coenzyme A oxidase. A potential mechanism for the hypolipidemic action of fibrates.

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    Epidemiological and transgenic animal studies have implicated apo C-III as a major determinant of plasma triglyceride metabolism. Since fibrates are very efficient in lowering triglycerides, it was investigated whether fibrates regulate apo C-III gene expression. Different fibrates lowered rat liver apo C-III mRNA levels up to 90% in a dose- and time-dependent manner, whereas intestinal apo C-III mRNA remained constant. This decrease in liver apo C-III mRNA was rapid (1 d) and reversible, since it was restored to control levels within 1 wk after cessation of treatment. In addition, fenofibrate treatment abolished the developmental rise of hepatic apo C-III mRNA observed during the suckling-weaning period. Administration of fibrates to rats induced liver and intestinal expression of the acyl CoA oxidase gene, the rate-limiting enzyme for peroxisomal beta-oxidation of fatty acids. In primary cultures of rat and human hepatocytes, fenofibric acid lowered apo C-III mRNA in a time- and dose-dependent manner. This reduction in apo C-III mRNA levels was accompanied by a decreased secretion of apo C-III in the culture medium of human hepatocytes. In rat hepatocytes fenofibric acid induced acyl CoA oxidase gene expression, whereas acyl CoA oxidase mRNA remained unchanged in human hepatocytes. Nuclear run-on and transient transfection experiments of a reporter construct driven by the human apo C-III gene promoter indicated that fibrates downregulate apo C-III gene expression at the transcriptional level. In conclusion, these studies demonstrate that fibrates decrease rat and human liver apo C-III gene expression. In humans the mechanisms appears to be independent of the induction of peroxisomal enzymes. This downregulation of liver apo C-III gene expression by fibrates may contribute to the hypotriglyceridemic action of these drugs

    Uso de morteros catalíticos sobre paneles, para el análisis de la reducción de partículas contaminantes en el aire

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    Trabajo de Investigación TecnológicaEste proyecto de grado se enfoca en la contaminación del aire y el uso de las nuevas tecnologías en la construcción para combatir este problema que genera afectaciones no solo ambientales, sino en la salud humana, en la flora y la fauna. La nanotecnología, es una rama que se desprende de las nuevas tecnologías y que se ha abierto paso en la industria de la construcción, por medio de la implementación de materiales y aditivos te tamaño nanométrico que mejoran y generan nuevas propiedades en los materiales comunes de construcción como el acero, concretos, morteros, pinturas, etc. En este proyecto se elaboró un concreto y mortero adicionando el Dióxido de titanio (TiO2), el cual actúa como un catalizador al combinarse con el cemento y los rayos ultra violeta, y su función principal es oxidar las partículas contaminantes suspendidas en el aire, por lo cual se categoriza como un descontaminante. Adicionalmente, el TiO2 puede mejorar las propiedades del concreto. Para comprobar el efecto del TiO2 en el concreto, se elaboraron cuatro cilindros de concreto común y de concreto adicionado, los cuales se fallaron en las edades típicas de falla y se compararon los resultados obtenidos. De igual manera, se fabricó un mortero adicionado, el cual se colocó sobre paneles y se dejó expuesto ocho días en un área de monitoreo de aire, y con los datos obtenidos se realizó el análisis correspondiente.1 INTRODUCCIÓN 2 ANTECEDENTES 3 PLANTEAMIENTO DEL PROBLEMA 4 OBJETIVOS 5 JUSTIFICACIÓN 6 DELIMITACIONES 7 MARCO DE REFERENCIA 8 METODOLOGÍA 9 DISEÑO METODOLÓGICO. 10 CONCLUSIONES 11 RECOMENDACIONES BIBLIOGRAFÍAPregradoIngeniero Civi

    Molecular identification of CTX-M and blaOXY/K1 β-lactamase genes in Enterobacteriaceae by sequencing of universal M13-sequence tagged PCR-amplicons

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    <p>Abstract</p> <p>Background</p> <p>Plasmid encoded <sup><it>bla</it></sup>CTX-M enzymes represent an important sub-group of class A β-lactamases causing the ESBL phenotype which is increasingly found in <it>Enterobacteriaceae </it>including <it>Klebsiella </it>spp. Molecular typing of clinical ESBL-isolates has become more and more important for prevention of the dissemination of ESBL-producers among nosocomial environment.</p> <p>Methods</p> <p>Multiple displacement amplified DNA derived from 20 <it>K. pneumoniae </it>and 34 <it>K. oxytoca </it>clinical isolates with an ESBL-phenotype was used in a universal CTX-M PCR amplification assay. Identification and differentiation of <sup><it>bla</it></sup>CTX-M and <sup><it>bla</it></sup>OXY/K1 sequences was obtained by DNA sequencing of M13-sequence-tagged CTX-M PCR-amplicons using a M13-specific sequencing primer.</p> <p>Results</p> <p>Nine out of 20 <it>K. pneumoniae </it>clinical isolates had a <sup><it>bla</it></sup>CTX-M genotype. Interestingly, we found that the universal degenerated primers also amplified the chromosomally located K1-gene in all 34 <it>K. oxytoca </it>clinical isolates. Molecular identification and differentiation between <sup><it>bla</it></sup>CTX-M and <sup><it>bla</it></sup>OXY/K1-genes could only been achieved by sequencing of the PCR-amplicons. <it>In silico </it>analysis revealed that the universal degenerated CTX-M primer-pair used here might also amplify the chromosomally located <sup><it>bla</it></sup>OXY and K1-genes in <it>Klebsiella </it>spp. and K1-like genes in other <it>Enterobacteriaceae</it>.</p> <p>Conclusion</p> <p>The PCR-based molecular typing method described here enables a rapid and reliable molecular identification of <sup><it>bla</it></sup>CTX-M, and <sup><it>bla</it></sup>OXY/K1-genes. The principles used in this study could also be applied to any situation in which antimicrobial resistance genes would need to be sequenced.</p

    AMPK Regulates Circadian Rhythms in a Tissue- and Isoform-Specific Manner

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    AMP protein kinase (AMPK) plays an important role in food intake and energy metabolism, which are synchronized to the light-dark cycle. In vitro, AMPK affects the circadian rhythm by regulating at least two clock components, CKIα and CRY1, via direct phosphorylation. However, it is not known whether the catalytic activity of AMPK actually regulates circadian rhythm in vivo.THE CATALYTIC SUBUNIT OF AMPK HAS TWO ISOFORMS: α1 and α2. We investigate the circadian rhythm of behavior, physiology and gene expression in AMPKα1-/- and AMPKα2-/- mice. We found that both α1-/- and α2-/- mice are able to maintain a circadian rhythm of activity in dark-dark (DD) cycle, but α1-/- mice have a shorter circadian period whereas α2-/- mice showed a tendency toward a slightly longer circadian period. Furthermore, the circadian rhythm of body temperature was dampened in α1-/- mice, but not in α2-/- mice. The circadian pattern of core clock gene expression was severely disrupted in fat in α1-/- mice, but it was severely disrupted in the heart and skeletal muscle of α2-/- mice. Interestingly, other genes that showed circadian pattern of expression were dysreguated in both α1-/- and α2-/- mice. The circadian rhythm of nicotinamide phosphoryl-transferase (NAMPT) activity, which converts nicotinamide (NAM) to NAD+, is an important regulator of the circadian clock. We found that the NAMPT rhythm was absent in AMPK-deficient tissues and cells.This study demonstrates that the catalytic activity of AMPK regulates circadian rhythm of behavior, energy metabolism and gene expression in isoform- and tissue-specific manners

    International Network for Comparison of HIV Neutralization Assays: The NeutNet Report II

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    BACKGROUND: Neutralizing antibodies provide markers for vaccine-induced protective immunity in many viral infections. By analogy, HIV-1 neutralizing antibodies induced by immunization may well predict vaccine effectiveness. Assessment of neutralizing antibodies is therefore of primary importance, but is hampered by the fact that we do not know which assay(s) can provide measures of protective immunity. An international collaboration (NeutNet) involving 18 different laboratories previously compared different assays using monoclonal antibodies (mAbs) and soluble CD4 (Phase I study). METHODS: In the present study (Phase II), polyclonal reagents were evaluated by 13 laboratories. Each laboratory evaluated nine plasmas against an 8 virus panel representing different genetic subtypes and phenotypes. TriMab, a mixture of three mAbs, was used as a positive control allowing comparison of the results with Phase I in a total of nine different assays. The assays used either uncloned virus produced in peripheral blood mononuclear cells (PBMCs) (Virus Infectivity Assays, VIA), or Env (gp160)-pseudotyped viruses (pseudoviruses, PSV) produced in HEK293T cells from molecular clones or from uncloned virus. Target cells included PBMC and genetically engineered cell lines in either single- or multiple-cycle infection format. Infection was quantified by using a range of assay read-outs including extra- or intra-cellular p24 antigen detection, luciferase, beta-galactosidase or green fluorescent protein (GFP) reporter gene expression. FINDINGS: Using TriMab, results of Phase I and Phase II were generally in agreement for six of the eight viruses tested and confirmed that the PSV assay is more sensitive than PBMC (p = 0.014). Comparisons with the polyclonal reagents showed that sensitivities were dependent on both virus and plasma. CONCLUSIONS: Here we further demonstrate clear differences in assay sensitivities that were dependent on both the neutralizing reagent and the virus. Consistent with the Phase I study, we recommend parallel use of PSV and VIA for vaccine evaluation
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