289 research outputs found

    High resolution (3 Tesla) MRI-guided conformal brachytherapy for cervical cancer: consequences of different high-risk CTV sizes

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    Purpose: To evaluate conventional brachytherapy (BT) plans using dose-volume parameters and high resolution (3 Tesla) MRI datasets, and to quantify dosimetric benefits and limitations when MRI-guided, conformal BT (MRIG-CBT) plans are generated. Material and methods: Fifty-five clinical high-dose-rate BT plans from 14 cervical cancer patients were retrospectively studied. All conventional plans were created using MRI with titanium tandem-and-ovoid applicator (T&O) for delivery. For each conventional plan, a MRIG-CBT plan was retrospectively generated using hybrid inverse optimization. Three categories of high risk (HR)-CTV were considered based on volume: non-bulky (\u3c 20 cc), low-bulky (\u3e 20 cc and \u3c 40 cc) and bulky (≥ 40 cc). Dose-volume metrics of D90 of HR-CTV and D2cc and D0.1cc of rectum, bladder, and sigmoid colon were analyzed. Results: Tumor coverage (HR-CTV D90) of the conventional plans was considerably affected by the HR-CTV size. Sixteen percent of the plans covered HR-CTV D90 with the prescription dose within 5%. At least one OAR had D2cc values over the GEC-ESTRO recommended limits in 52.7% of the conventional plans. MRIG-CBT plans showed improved target coverage for HR-CTV D90 of 98 and 97% of the prescribed dose for non-bulky and low-bulky tumors, respectively. No MRIG-CBT plans surpassed the D2cc limits of any OAR. Only small improvements (D90 of 80%) were found for large targets (\u3e 40 cc) when using T&O applicator approach. Conclusions: MRIG-CBT plans displayed considerable improvement for tumor coverage and OAR sparing over conventional treatment. When the HR-CTV volume exceeded 40 cc, its improvements were diminished when using a conventional intracavitary applicator

    Mutational and Structural Analysis of KIR3DL1 Reveals a Lineage-Defining Allotypic Dimorphism That Impacts Both HLA and Peptide Sensitivity

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    Killer Ig-like receptors (KIRs) control the activation of human NK cells via interactions with peptide-laden HLAs. KIR3DL1 is a highly polymorphic inhibitory receptor that recognizes a diverse array of HLA molecules expressing the Bw4 epitope, a group with multiple polymorphisms incorporating variants within the Bw4 motif. Genetic studies suggest that KIR3DL1 variation has functional significance in several disease states, including HIV infection. However, owing to differences across KIR3DL1 allotypes, HLA-Bw4, and associated peptides, the mechanistic link with biological outcome remains unclear. In this study, we elucidated the impact of KIR3DL1 polymorphism on peptide-laden HLA recognition. Mutational analysis revealed that KIR residues involved in water-mediated contacts with the HLA-presented peptide influence peptide binding specificity. In particular, residue 282 (glutamate) in the D2 domain underpins the lack of tolerance of negatively charged C-terminal peptide residues. Allotypic KIR3DL1 variants, defined by neighboring residue 283, displayed differential sensitivities to HLA-bound peptide, including the variable HLA-B*57:01-restricted HIV-1 Gag-derived epitope TW10. Residue 283, which has undergone positive selection during the evolution of human KIRs, also played a central role in Bw4 subtype recognition by KIR3DL1. Collectively, our findings uncover a common molecular regulator that controls HLA and peptide discrimination without participating directly in peptide-laden HLA interactions. Furthermore, they provide insight into the mechanics of interaction and generate simple, easily assessed criteria for the definition of KIR3DL1 functional groupings that will be relevant in many clinical applications, including bone marrow transplantation

    Age-dependent loss of cohesion protection in human oocytes

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    Aneuploid human eggs (oocytes) are a major cause of infertility, miscarriage, and chromosomal disorders. Such aneuploidies increase greatly as women age, with defective linkages between sister chromatids (cohesion) in meiosis as a common cause. We found that loss of a specific pool of the cohesin protector protein, shugoshin 2 (SGO2), may contribute to this phenomenon. Our data indicate that SGO2 preserves sister chromatid cohesion in meiosis by protecting a ‘‘cohesin bridge’’ between sister chromatids. In human oocytes, SGO2 localizes to both sub-centromere cups and the pericentromeric bridge, which spans the sister chromatid junction. SGO2 normally colocalizes with cohesin; however, in meiosis II oocytes from older women, SGO2 is frequently lost from the pericentromeric bridge and sister chromatid cohesion is weakened. MPS1 and BUB1 kinase activities maintain SGO2 at sub-centromeres and the pericentromeric bridge. Removal of SGO2 throughout meiosis I by MPS1 inhibition reduces cohesion protection, increasing the incidence of single chromatids at meiosis II. Therefore, SGO2 deficiency in human oocytes can exacerbate the effects of maternal age by rendering residual cohesin at pericentromeres vulnerable to loss in anaphase I. Our data show that impaired SGO2 localization weakens cohesion integrity and may contribute to the increased incidence of aneuploidy observed in human oocytes with advanced maternal age

    La Imagen y la Narrativa como Herramientas para el Abordaje Psicosocial en Escenarios de Violencia, Zona Centro Departamento de Boyacá

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    Este trabajo consiste en presentar el análisis de los factores psicosociales emergentes que yacen de las consecuencias de la violencia que atraviesa nuestra nación. Inicialmente se realiza el análisis del caso seleccionado por el grupo colaborativo. En el “Relato 5: Carlos Arturo”, se consideran aspectos principalmente enmarcados a los fragmentos que más llaman la atención del relato desde un enfoque psicosocial en base a artículos científicos propuestos durante el diplomado de profundización en escenarios de violencia, también se analizan los impactos psicosociales que podemos reconocer en el contexto del protagonista de la historia y de igual forma generamos una respuesta a las voces que logramos encontrar en la narración toda vez que revelan un posicionamiento intransferible desde el lugar de la víctima o el superviviente que narra su experiencia, a lo largo de este documento podemos comprender algunos destacados electivos respecto a imágenes imperiosas de la violencia y sus impactos establecidos para finalmente poder registrar apartes que emergen una autonomía complexa frente a las imágenes de pánico de la violencia. Posteriormente el grupo colaborativo reflexiona en el caso propuesto “las comunidades de Cacarica”, el cual muestra el entorno a los procedentes psicosociales que consideramos están ocultos después de la corrida y el acoso militar. También se analizan los impactos que genera para la población el hecho de ser estigmatizada como cómplices de un actor armado. A continuación, el grupo propone dos acciones de apoyo en la situación de crisis generada por la tortura y el asesinato de miembros y líderes de la comunidad de estudio y finalmente se logran instituir tres destrezas psicosociales con los pobladores de Cacarica, que facilitan la potenciación de recursos de resistencia a la situación indicada por la problemática.This work is about the psychosocial facts found in the consequences of violence that suffer our country. At the beginning, we did the case analysis that we selected as a collaborative team. In the "Report 5: Carlos Arturo" it is considered by mainly framed aspects to the most important fragments that we care about from a psychologic approach based in scientific articles proposed all across the strengthening degree in scenes of violence. Also, the psychosocial impacts that we recognized in the story's protagonist context are analyzed. Besides, we generate an answer to the voices that we can find in the story whenever they reveal a subjective positioning from the victim's place who tells the story. Throughout this document we can get understand some alternate meanings regarding dominant images of violence and its naturalized impacts to finally be able to register parts that reveal a discursive emancipation in front of the horror images of violence. Later, the collaborative group reflects on the proposed case: “the communities of Cacarica”, which shows the environment to the psychosocial emerging who we consider to be latent after the incursion and military harassment. It also analyses the impact on the population of being stigmatized as accomplices of an armed actor. The group then proposes two actions to support the crisis situation generated by the torture and murder of members and leaders of the study community, and finally three psychosocial strategies have been establish with the people of Cacarica, facilitating the development of resources to deal with the situation expressed by the problem

    LAB/NTAL Facilitates Fungal/PAMP-induced IL-12 and IFN-γ Production by Repressing β-Catenin Activation in Dendritic Cells.

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    Fungal pathogens elicit cytokine responses downstream of immunoreceptor tyrosine-based activation motif (ITAM)-coupled or hemiITAM-containing receptors and TLRs. The Linker for Activation of B cells/Non-T cell Activating Linker (LAB/NTAL) encoded by Lat2, is a known regulator of ITAM-coupled receptors and TLR-associated cytokine responses. Here we demonstrate that LAB is involved in anti-fungal immunity. We show that Lat2−/− mice are more susceptible to C. albicans infection than wild type (WT) mice. Dendritic cells (DCs) express LAB and we show that it is basally phosphorylated by the growth factor M-CSF or following engagement of Dectin-2, but not Dectin-1. Our data revealed a unique mechanism whereby LAB controls basal and fungal/pathogen-associated molecular patterns (PAMP)-induced nuclear β-catenin levels. This in turn is important for controlling fungal/PAMP-induced cytokine production in DCs. C. albicans- and LPS-induced IL-12 and IL-23 production was blunted inLat2−/− DCs. Accordingly, Lat2−/− DCs directed reduced Th1 polarization in vitro and Lat2−/−mice displayed reduced Natural Killer (NK) and T cell-mediated IFN-γ production in vivo/ex vivo. Thus our data define a novel link between LAB and β-catenin nuclear accumulation in DCs that facilitates IFN-γ responses during anti-fungal immunity. In addition, these findings are likely to be relevant to other infectious diseases that require IL-12 family cytokines and an IFN-γ response for pathogen clearance

    Confronting Uncertainty in Wildlife Management: Performance of Grizzly Bear Management

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    Scientific management of wildlife requires confronting the complexities of natural and social systems. Uncertainty poses a central problem. Whereas the importance of considering uncertainty has been widely discussed, studies of the effects of unaddressed uncertainty on real management systems have been rare. We examined the effects of outcome uncertainty and components of biological uncertainty on hunt management performance, illustrated with grizzly bears (Ursus arctos horribilis) in British Columbia, Canada. We found that both forms of uncertainty can have serious impacts on management performance. Outcome uncertainty alone – discrepancy between expected and realized mortality levels – led to excess mortality in 19% of cases (population-years) examined. Accounting for uncertainty around estimated biological parameters (i.e., biological uncertainty) revealed that excess mortality might have occurred in up to 70% of cases. We offer a general method for identifying targets for exploited species that incorporates uncertainty and maintains the probability of exceeding mortality limits below specified thresholds. Setting targets in our focal system using this method at thresholds of 25% and 5% probability of overmortality would require average target mortality reductions of 47% and 81%, respectively. Application of our transparent and generalizable framework to this or other systems could improve management performance in the presence of uncertainty. &nbsp
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