546 research outputs found
INFECTION AND TRANSFORMATION OF MOUSE PERITONEAL MACROPHAGES BY SIMIAN VIRUS 40
The stimulation of DNA synthesis in mouse (C57BL) macrophages explanted in vitro was demonstrated after treatment with conditioned medium or infection with SV40. In the latter case, induction of SV40 T antigen was detected before TdR-3H incorporation. Even though all macrophages were infected (T antigen-positive), they exhibited considerable pleomorphism, accompanied by functional differences. Permanent lines of SV40-transformed macrophages were eventually established, and one clone was isolated which replicates indefinitely and has many properties of primary macrophages: high acid phosphatase and phagocytic activity, lysozyme production, and specific antigenic determinants. These cells differ from normal macrophages in that they contain the SV40 genome, can be trypsinized, and do not require conditioned medium for continued replication
A 10B-based neutron detector with stacked Multiwire Proportional Counters and macrostructured cathodes
We present the results of the measurements of the detection efficiency for a
4.7 \r{A} neutron beam incident upon a detector incorporating a stack of up to
five MultiWire Proportional Counters (MWPC) with Boron-coated cathodes. The
cathodes were made of Aluminum and had a surface exhibiting millimeter-deep
V-shaped grooves of 45{\deg}, upon which the thin Boron film was deposited by
DC magnetron sputtering. The incident neutrons interacting with the converter
layer deposited on the sidewalls of the grooves have a higher capture
probability, owing to the larger effective absorption film thickness. This
leads to a higher overall detection efficiency for the grooved cathode when
compared to a cathode with a flat surface. Both the experimental results and
the predictions of the GEANT4 model suggests that a 5-counter detector stack
with coated grooved cathodes has the same efficiency as a 7-counter stack with
flat cathodes. The reduction in the number of counters in the stack without
altering the detection efficiency will prove highly beneficial for large-area
position-sensitive detectors for neutron scattering applications, for which the
cost-effective manufacturing of the detector and associated readout electronics
is an important objective. The proposed detector concept could be a
technological option for one of the new chopper spectrometers and other
instruments planned to be built at the future European Spallation Source in
Sweden. These results with macrostructured cathodes generally apply not just to
MWPCs but to other gaseous detectors as well.Comment: 14 pages, 9 figure
LA BACTERICIDIE DES NEUTROPHILES : MECANISMES CELLULAIRES ET MOLECULAIRES ET LEURS DYSFONCTIONS
Microbicidal activity of neutrophils requires the NADPH oxidase dependent reactive oxygen species (ROS) production and myeloperoxidase (MPO)-H2O2-halide system-catalyzed halogenations (oxidative mechanisms) and the release of granular proteins into the phagosomal lumen (non oxidative mechanisms). The long-established direct role of ROS and MPO has been recently questioned. In this work, using our improved method to assess microbicidal activity, we have re-examined the role of the diverse mechanisms proposed to be involved in the antimicrobial activity of neutrophils. We show that the NADPH oxidase activity is indispensable for the killing of certain microorganisms (e.g. Staphylococcus aureus, Candida albicans) but not of others (e.g. Escherichia coli) which are efficiently killed even in the absence of a respiratory burst. Our data also indicate that NADPH oxidase-dependent killing of S. aureus and C. albicans is largely dependent on MPO. Alkalinization of phagosomal pH and K+ fluxes do not appear to significantly contribute to the killing of these microorganisms. K+ channels activity may account for the partial recovery of killing observed in MPO-deficient neutrophils at long times of incubation.We have also investigated the neutrophils’ microbicidal mechanisms in a cellular model, the human myelomonoblastic cellular line inducible in granulocytes, PLB-985. The ROS production in PLB-985 cells stimulated by opsonized microorganisms is very weak compared to human neutrophils, but sustains a NADPH oxidase dependent killing activity of S. aureus and C. albicans similar to PMN after short times of incubation (<10 min). However, the killing activity of the PLB cells is abolished after long times of incubation. NADPH oxidase independent killing of E. coli is also defective. The ROS overproduction of the mutant DloopNox4-Nox2 (in these cells, the D-loop of Nox2 was replaced by the D-loop of its homolog Nox4) after soluble and particulate agonists dependent activation does not increase their microbicidal power. The weak killing activity of the PLB-985 cellular line can be explained by the faint amounts of cytochrome b558 and by the more or less lack of granular proteins content (MPO, elastase, cathepsine G, lactoferrine, lysozyme, MMP8 and MMP9) involved in the microbicidal event. In conclusion, in PLB-985 DMF-differentiated cells, the oxygen dependent and independent mechanisms are both defective. A lack of NADPH oxidase complex results in a rare inherited disorder, the chronic granulomatose disease (CGD). We characterized an atypical and extremely rare case of CGD: the X91- variant: the new identified point mutation in the CYBB gene promoter (insertion of a T at position -54T/-56T) appeared to be related to the loss of association of ets transcription factors within this region, prevent the normally functional expression of the gene and finally, correlate with the low NADPH oxidase activity. The residual respiratory burst supported no killing of S. aureus and C. albicans, in vitro, and is not sufficient to protect the patient against severe and recurrent infections.L’élimination des microorganismes par les neutrophiles (PMN) est mediée par l’activité des formes réactives de l’oxygène (FRO), produites suite à l’activation de la NADPH oxydase, dont l’efficacité est sensiblement augmentée par la myélopéroxydase, MPO, (mécanismes oxydatifs) et par l’action des protéines bactéricides contenues dans les granules cytoplasmiques (mécanismes non oxydatifs). L’implication directe des FRO et de la MPO dans la bactéricidie des PMN a été récemment remise en question. Nous nous sommes proposés de réexaminer les mécanismes impliqués dans la bactéricidie des neutrophiles sur la base des nouvelles hypothèses récemment proposées en appliquant une méthode de mesure du « killing » des microorganismes que nous avons récemment mise au point et qui permet une estimation plus correcte de la bactéricidie. Nous avons démontré que l’activité NADPH oxydase est indispensable pour le « killing » de certains microorganismes (S. aureus et C. albicans) mais pas pour d’autres (E. coli) qui sont efficacement éliminés même en l’absence du burst respiratoire. Les flux d’ions K+ et l’alcalinisation du pH intraphagosomale, induits par l’activation du complexe oxydase, ne sont pas nécessaires au killing de S. aureus et C. albicans, microorganismes dont la bactéricidie NADPH oxydase dépendante est mediée presque exclusivement par la MPO. Les courants des ions K+, à travers des canaux BKCa-like, semblent être responsables du killing résiduel des PMN MPO déficients, après une longue incubation. Nous avons aussi étudié les mécanismes impliqués dans la bactéricidie des PMN en utilisant comme modèle cellulaire la lignée PLB-985 différentiable en « pseudo-neutrophiles ». Nous avons prouvé que la réponse de ces cellules aux stimuli particulaires est sensiblement plus faible par rapport aux PMN. Ce burst respiratoire support e une bactéricidie comparable à celles des PMN pour des temps courts d’incubation (<10 min) vis-à -vis des microorganismes sensibles aux mécanismes de « killing » oxygène-dépendants (S. aureus et C. albicans); toutefois, en prolongeant les temps d’incubation, le pouvoir bactéricides ce ces cellules est abolit. Le « killing » NADPH oxydase indépendant d’E. coli est aussi partiellement déficitaire. La superproduction de FRO mise en évidence dans les cellules mutantes PLB-985 DloopNox4-Nox2 (où la deuxième boucle intracellulaire de Nox2 a été remplacée par celle de l’oxydase homologue Nox4) en réponse aux stimuli solubles et particulaires n’est pas accompagnée par une augmentation du « killing ». Le faible pouvoir bactéricide de cette lignée cellulaire est du au contenu réduit en cytochrome b558 (un dixième par rapport aux PMN) et aux défauts plus ou moins importants des protéines granulaires (MPO, elastase, cathepsine G, lactoferrine, lysozyme, MMP8 et MMP9) impliquées dans le processus de bactéricidie: dans les cellules PLB-985 différentiées au DMF, les mécanismes bactéricides oxygènes dépendants et indépendants sont donc tous deux compromis.Le dysfonctionnement du complexe NADPH oxydase est à la base d’une maladie génétique rare, la granulomatose septique chronique (CGD). Nous nous sommes intéressés à la caractérisation d’un cas atypique de CGD, la forme X91-. Nous avons démontré que la nouvelle mutation identifiée (insertion d’un T en position -54T/-56T) compromet l’association des facteurs de transcription ets avec la région promotrice, empêche, par conséquence, l’expression normale du gène dans les neutrophiles et détermine une activité oxydase réduite. Ce burst respiratoire résiduel (6% du control) n’est pas suffisante pour soutenir, in vitro, une activité de « killing » vis-à -vis de S. aureus et C. albicans ni pour protéger le patient des infections sévères et récidivantes
LA BACTERICIDIE DES NEUTROPHILES : MECANISMES CELLULAIRES ET MOLECULAIRES ET LEURS DYSFONCTIONS
Microbicidal activity of neutrophils requires the NADPH oxidase dependent reactive oxygen species (ROS) production and myeloperoxidase (MPO)-H2O2-halide system-catalyzed halogenations (oxidative mechanisms) and the release of granular proteins into the phagosomal lumen (non oxidative mechanisms). The long-established direct role of ROS and MPO has been recently questioned. In this work, using our improved method to assess microbicidal activity, we have re-examined the role of the diverse mechanisms proposed to be involved in the antimicrobial activity of neutrophils. We show that the NADPH oxidase activity is indispensable for the killing of certain microorganisms (e.g. Staphylococcus aureus, Candida albicans) but not of others (e.g. Escherichia coli) which are efficiently killed even in the absence of a respiratory burst. Our data also indicate that NADPH oxidase-dependent killing of S. aureus and C. albicans is largely dependent on MPO. Alkalinization of phagosomal pH and K+ fluxes do not appear to significantly contribute to the killing of these microorganisms. K+ channels activity may account for the partial recovery of killing observed in MPO-deficient neutrophils at long times of incubation.We have also investigated the neutrophils’ microbicidal mechanisms in a cellular model, the human myelomonoblastic cellular line inducible in granulocytes, PLB-985. The ROS production in PLB-985 cells stimulated by opsonized microorganisms is very weak compared to human neutrophils, but sustains a NADPH oxidase dependent killing activity of S. aureus and C. albicans similar to PMN after short times of incubation (<10 min). However, the killing activity of the PLB cells is abolished after long times of incubation. NADPH oxidase independent killing of E. coli is also defective. The ROS overproduction of the mutant DloopNox4-Nox2 (in these cells, the D-loop of Nox2 was replaced by the D-loop of its homolog Nox4) after soluble and particulate agonists dependent activation does not increase their microbicidal power. The weak killing activity of the PLB-985 cellular line can be explained by the faint amounts of cytochrome b558 and by the more or less lack of granular proteins content (MPO, elastase, cathepsine G, lactoferrine, lysozyme, MMP8 and MMP9) involved in the microbicidal event. In conclusion, in PLB-985 DMF-differentiated cells, the oxygen dependent and independent mechanisms are both defective. A lack of NADPH oxidase complex results in a rare inherited disorder, the chronic granulomatose disease (CGD). We characterized an atypical and extremely rare case of CGD: the X91- variant: the new identified point mutation in the CYBB gene promoter (insertion of a T at position -54T/-56T) appeared to be related to the loss of association of ets transcription factors within this region, prevent the normally functional expression of the gene and finally, correlate with the low NADPH oxidase activity. The residual respiratory burst supported no killing of S. aureus and C. albicans, in vitro, and is not sufficient to protect the patient against severe and recurrent infections.L’élimination des microorganismes par les neutrophiles (PMN) est mediée par l’activité des formes réactives de l’oxygène (FRO), produites suite à l’activation de la NADPH oxydase, dont l’efficacité est sensiblement augmentée par la myélopéroxydase, MPO, (mécanismes oxydatifs) et par l’action des protéines bactéricides contenues dans les granules cytoplasmiques (mécanismes non oxydatifs). L’implication directe des FRO et de la MPO dans la bactéricidie des PMN a été récemment remise en question. Nous nous sommes proposés de réexaminer les mécanismes impliqués dans la bactéricidie des neutrophiles sur la base des nouvelles hypothèses récemment proposées en appliquant une méthode de mesure du « killing » des microorganismes que nous avons récemment mise au point et qui permet une estimation plus correcte de la bactéricidie. Nous avons démontré que l’activité NADPH oxydase est indispensable pour le « killing » de certains microorganismes (S. aureus et C. albicans) mais pas pour d’autres (E. coli) qui sont efficacement éliminés même en l’absence du burst respiratoire. Les flux d’ions K+ et l’alcalinisation du pH intraphagosomale, induits par l’activation du complexe oxydase, ne sont pas nécessaires au killing de S. aureus et C. albicans, microorganismes dont la bactéricidie NADPH oxydase dépendante est mediée presque exclusivement par la MPO. Les courants des ions K+, à travers des canaux BKCa-like, semblent être responsables du killing résiduel des PMN MPO déficients, après une longue incubation. Nous avons aussi étudié les mécanismes impliqués dans la bactéricidie des PMN en utilisant comme modèle cellulaire la lignée PLB-985 différentiable en « pseudo-neutrophiles ». Nous avons prouvé que la réponse de ces cellules aux stimuli particulaires est sensiblement plus faible par rapport aux PMN. Ce burst respiratoire support e une bactéricidie comparable à celles des PMN pour des temps courts d’incubation (<10 min) vis-à -vis des microorganismes sensibles aux mécanismes de « killing » oxygène-dépendants (S. aureus et C. albicans); toutefois, en prolongeant les temps d’incubation, le pouvoir bactéricides ce ces cellules est abolit. Le « killing » NADPH oxydase indépendant d’E. coli est aussi partiellement déficitaire. La superproduction de FRO mise en évidence dans les cellules mutantes PLB-985 DloopNox4-Nox2 (où la deuxième boucle intracellulaire de Nox2 a été remplacée par celle de l’oxydase homologue Nox4) en réponse aux stimuli solubles et particulaires n’est pas accompagnée par une augmentation du « killing ». Le faible pouvoir bactéricide de cette lignée cellulaire est du au contenu réduit en cytochrome b558 (un dixième par rapport aux PMN) et aux défauts plus ou moins importants des protéines granulaires (MPO, elastase, cathepsine G, lactoferrine, lysozyme, MMP8 et MMP9) impliquées dans le processus de bactéricidie: dans les cellules PLB-985 différentiées au DMF, les mécanismes bactéricides oxygènes dépendants et indépendants sont donc tous deux compromis.Le dysfonctionnement du complexe NADPH oxydase est à la base d’une maladie génétique rare, la granulomatose septique chronique (CGD). Nous nous sommes intéressés à la caractérisation d’un cas atypique de CGD, la forme X91-. Nous avons démontré que la nouvelle mutation identifiée (insertion d’un T en position -54T/-56T) compromet l’association des facteurs de transcription ets avec la région promotrice, empêche, par conséquence, l’expression normale du gène dans les neutrophiles et détermine une activité oxydase réduite. Ce burst respiratoire résiduel (6% du control) n’est pas suffisante pour soutenir, in vitro, une activité de « killing » vis-à -vis de S. aureus et C. albicans ni pour protéger le patient des infections sévères et récidivantes
Effects of the physical properties of water masses on microbial activity during an Ice Shelf Water overflow in the central Ross Sea
During the 1997-98 Italian Expedition to Antarctica a five-day mesoscale experiment was carried out on the continental shelf-break in the central Ross Sea. This area is oceanographically characterized by shelf/slope interactions, through intense mixing processes, between the Circumpolar Deep Water (CDW) and the Ice Shelf Water (ISW), coming from beneath the Ross Ice Shelf and spilling over the shelf edge. The export of dense shelf waters is of crucial importance not only for the mass balance of the basin, but also for carbon export from the upper layers into the abyssal ones. The study investigated how the ISW interactions with the CDW may influence bacterial metabolism during an ISW downslope event. In particular, what effect does this have on the bacterial activities related to the utilization and transformation of the organic carbon substrate (ectoenzymatic activities, carbon production, growth rate) within the ISW and the CDW cores? Our data show that in the CDW the metabolic response was to increase the biomass and enzymes were less active due to a higher nutritional value for the substrate. In the ISW the bacterial metabolic activity shifted towards degradative processes. These results suggest differences in the quality of the organic carbon pool with a greater concentration of labile organic matter in the CDW and of low-degradable compounds in the ISW. The use of microbial parameters seems to be very promising in the evaluation of the carbon export during mixing processes, when the refractory fraction of the organic carbon pool might play a key role
Análise dos fatores estilĂsticos envolvidos na fala de um rapper em diferentes situações comunicativas
Neste artigo, temos por objetivo descrever e analisar as diferenças estilĂsticas resultantes das manipulações estratĂ©gicas de recursos linguĂstico-discursivos produzidas por um rapper paulista protagonista de movimento social, nas seguintes situações comunicativas: fala pĂşblica e depoimento. Nossa análise privilegiou o modelo do estilo desenvolvido por Bell (2001), que postula como fatores determinantes para a variação estilĂstica o design de audiĂŞncia e o de referĂŞncia. Procedemos Ă descrição da organização hierárquica e da segmentação linear dos tĂłpicos discursivos dos textos orais do rapper Mano Brown. Sendo o design de audiĂŞncia o fator condicionante da variação estilĂstica, o fenĂ´meno textual tĂłpico discursivo se apresenta como um dos principais lĂłcus de observação dessa variação
Abordagem da vigilância epidemiolĂłgica e da promoção da saĂşde na atenção básica perspectivas de mĂ©dicos de equipes saĂşde da famĂlia
Trabalho de Conclusão de Curso (Graduação)Analisar o conhecimento e o envolvimento de médicos de equipes da Estratégia Saúde da
FamĂlia (ESF) de municĂpios do interior do estado de Minas Gerais em relação Ă Vigilância
Epidemiológica (VIGEP) e à Promoção da Saúde (PS). Trata-se de estudo qualitativo
desenvolvido com a técnica de grupo focal no qual participaram oito médicos. O grupo focal
foi conduzido com o emprego de situação-problema e submetido à análise de conteúdo temática.
Os participantes exploraram dimensões da VIGEP e da PS, suas relações com a atuação da ESF
e sugeriram intervenções como visitas domiciliares, grupos operativos e mobilização de outros
setores. A formação acadêmica baseada no modelo assistencial curativista, a rotina intensa de
trabalho e a dificuldade de incorporação de dados epidemiológicos no cotidiano dos serviços
foram as principais dificuldades relatadas. A integralidade da atenção requer melhorias nas
condições de trabalho das equipes, expansão das iniciativas de promoção da saúde e
envolvimento comunitário. A educação permanente em saúde se constitui em estratégia
fundamental para a ampliação do conhecimento dos profissionais e incremento da atuação
integrada da VS e ESF
O Corpo-unileiro - Saúde, Migração e Fronteira: Diálogos Antropológicos
Trabalho de ConclusĂŁo de Curso apresentado ao Instituto Latino-Americano de Arte, Cultura e HistĂłria da Universidade Federal da Integração Latino-Americana, como requisito parcial Ă obtenção do tĂtulo de Bacharel em Antropologia – Diversidade Cultural Latino-Americana.O presente trabalho objetiva analisar a relação dos estudantes nĂŁo-brasileiros da Universidade Federal da Integração Latino-Americana - UNILA com os serviços de saĂşde, seja no âmbito interno da instituição ou externo na rede de atendimento da cidade. A pesquisa parte de uma compreensĂŁo antropolĂłgica onde os fatores culturais sĂŁo relevantes para entender o processo saĂşde-doença e a complexidade dessas realidades do ponto de vista da migração. Portanto, parto da perspectiva de que a instituição pode ser entendida como um corpo entre docentes, discentes e tĂ©cnicos, que no caso da UNILA, tornam-se o
“corpo-unileiro”, categoria social e biolĂłgica com necessidades de cuidado e apoio especĂficos. Trata-se de uma pesquisa etnográfica onde recorri Ă s histĂłrias e os relatos, a revisĂŁo de literatura, notĂcias e redes sociais, conversas e entrevistas, identificar na vivĂŞncia as demandas dos estudantes. Finalmente, proponho pensar as especificidades nas polĂticas em saĂşde dos estudantes e os caminhos para chegarmos a PolĂticas Interculturais de SaĂşde na fronteira. Desde já observo que, na criação da UNILA, pouco tem sido feito para a criação de um sistema que possa atender satisfatoriamente as particularidades dos discentes dos paĂses latino-americanos. Para tanto, faz-se necessário construir, junto ao corpo-unileiro e os municĂpios da fronteira, polĂticas de saĂşde e de acolhimento nos serviços pĂşblicos que sejam eficazes Ă s demandas de sua população
- …