Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
BMC Health Serv Res ; 20(1): 558, 2020 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-32552833

RESUMEN

BACKGROUND: Liver cirrhosis is a leading cause of morbidity, premature mortality and acute care utilization in patients with digestive disease. In the province of Alberta, hospital readmission rates for patients with cirrhosis are estimated at 44% at 90 days. For hospitalized patients, multiple care gaps exist, the most notable stemming from i) the lack of a structured approach to best practice care for cirrhosis complications, ii) the lack of a structured approach to broader health needs and iii) suboptimal preparation for transition of care into the community. Cirrhosis Care Alberta (CCAB) is a 4-year multi-component pragmatic trial which aims to address these gaps. The proposed intervention is initiated at the time of hospitalization through implementation of a clinical information system embedded electronic order set for delivering evidence-based best practices under real-world conditions. The overarching objective of the CCAB trial is to demonstrate effectiveness and implementation feasibility for use of the order set in routine patient care within eight hospital sites in Alberta. METHODS: A mixed methods hybrid type I effectiveness-implementation design will be used to evaluate the effectiveness of the order set intervention. The primary outcome is a reduction in 90-day cumulative length of stay. Implementation outcomes such as reach, adoption, fidelity and maintenance will also be evaluated alongside other patient and service outcomes such as readmission rates, quality of care and cost-effectiveness. This theory-based trial will be guided by Normalization Process Theory, Consolidated Framework on Implementation Research (CFIR) and the Reach-Effectiveness-Adoption-Implementation-Maintenance (RE-AIM) Framework. DISCUSSION: The CCAB project is unique in its breadth, both in the comprehensiveness of the multi-component order set and also for the breadth of its roll-out. Lessons learned will ultimately inform the feasibility and effectiveness of this approach in "real-world" conditions as well as adoption and adaptation of these best practices within the rest of Alberta, other provinces in Canada, and beyond. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04149223, November 4, 2019.


Asunto(s)
Análisis Costo-Beneficio , Cirrosis Hepática/terapia , Alberta , Humanos , Tiempo de Internación
2.
Int Immunol ; 21(4): 423-32, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19261694

RESUMEN

NK cell cytotoxicity requires two positive signals for killing of tumors. Activation receptors induce polarization of the microtubule organization center and degranulation, while leukocyte function-associated antigen (LFA)-1 is required for conjugate formation and actin polymerization and under some circumstances may be sufficient for NK cell cytotoxicity. Although the receptor for direct killing of fungi is not known, CD18, the beta2 chain of LFA-1, binds components of the capsule and cell wall of the opportunistic pathogen Cryptococcus neoformans, namely the polysaccharides glucoronoxylomannan and galactoxylomannan. Herein, we also demonstrate that LFA-1 was concentrated in regions of the NK cell surface interacting with C. neoformans. Consequently, there was compelling evidence to hypothesize that NK cells would also use LFA-1 to recognize and kill C. neoformans. Using a combination of NK cell lines that did or did not express LFA-1 or by using a CD18-specific functional blocking antibody, we confirm that NK cell anti-tumor activity is critically dependent upon the expression of LFA-1. Duplicating the events of tumor cytotoxicity, NK cells form conjugates with cryptococcal targets, rearrange the cell cytoskeleton to develop an NK immunologic synapse and release perforin-containing granules; however, each of these events occurred independently of LFA-1. Furthermore, NK cell-mediated killing of C. neoformans was detectable in both NK cells pre-treated with CD18-blocking antibodies and in NK cells lacking cell surface LFA-1 expression. These results demonstrate that in the absence of LFA-1 expression, NK cells are fully capable of recognizing a target (C. neoformans) and retain all of the events required for cytotoxicity.


Asunto(s)
Antígenos CD18/inmunología , Cryptococcus neoformans/inmunología , Citotoxicidad Inmunológica , Células Asesinas Naturales/inmunología , Antígeno-1 Asociado a Función de Linfocito/inmunología , Neoplasias/inmunología , Actinas/inmunología , Actinas/metabolismo , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/metabolismo , Antígenos CD18/metabolismo , Degranulación de la Célula/inmunología , Línea Celular Tumoral , Citoesqueleto/inmunología , Citoesqueleto/metabolismo , Humanos , Células Asesinas Naturales/metabolismo , Antígeno-1 Asociado a Función de Linfocito/genética , Antígeno-1 Asociado a Función de Linfocito/metabolismo , Perforina/inmunología , Perforina/metabolismo , Transducción de Señal/inmunología
3.
Nutr Clin Pract ; 35(1): 119-125, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30806489

RESUMEN

BACKGROUND: To explore the influence of nourishment state measured by various nutrition assessment tools (NATs) on health-related quality of life (HRQoL) in a pretransplant population with cirrhosis. METHODS: We collected demographic, nutrition assessment, and disease specific data on 81 patients. HRQoL was measured with the Short-Form 36 and divided into 8 subscales. Significant relationships between NATs and HRQoL were examined using independent sample t-tests, χ2 analyses, correlations, and multiple and logistic regression adjusted for age and gender. RESULTS: Study mean age was 54.2 years (SD 10.4 years), and 57% were male. Subjective Global Assessment (SGA) was significantly related to all HRQoL subscales, except bodily pain and mental health. In the adjusted regression models, general health, vitality, and social functioning were all significantly lower in patients with poorer nutrition status measured using SGA (adjusted R2 = 11%, ß = -0.34, p < 0.01; adjusted R2 = 8%, ß = -0.27, P < 0.05; and adjusted R2 = 12%, ß = -0.38, P < 0.01, Q4 respectively). Physical functioning improved as hand grip strength increased (adjusted R2 = 20%, ß = 0.36, P < 0.01). MELDNa demonstrated a significant negative relationship with role-emotional (adjusted R2 = 3%, ß = 0.25, P < 0.05), and mid-arm circumference did not demonstrate any significant relationships with HRQoL. CONCLUSIONS: Malnutrition assessed by SGA is associated with lower HRQoL in patients with cirrhosis. Future research should identify if nutrition interventions can effectively improve HRQoL in cirrhosis patients.


Asunto(s)
Cirrosis Hepática/epidemiología , Desnutrición/epidemiología , Evaluación Nutricional , Calidad de Vida , Adulto , Anciano , Estudios Transversales , Femenino , Fuerza de la Mano , Estado de Salud , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Estado Nutricional , Encuestas y Cuestionarios
4.
Infect Immun ; 77(6): 2436-46, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19307209

RESUMEN

NK cells, in addition to possessing antitumor and antiviral activity, exhibit perforin-dependent microbicidal activity against the opportunistic pathogen Cryptococcus neoformans. However, the factors controlling this response, particularly whether the pathogen itself provides an activation or rearming signal, are largely unknown. The current studies were performed to determine whether exposure to this fungus alters subsequent NK cell anticryptococcal activity. NK cells lost perforin and mobilized lysosome-associated membrane protein 1 to the cell surface following incubation with the fungus, indicating that degranulation had occurred. Despite a reduced perforin content during killing, NK cells acquired an enhanced ability to kill C. neoformans, as demonstrated using auxotrophs that allowed independent assessment of the killing of two strains. De novo protein synthesis was required for optimal killing; however, there was no evidence that a soluble factor contributed to the enhanced anticryptococcal activity. Exposure of NK cells to C. neoformans caused the cells to rearm, as demonstrated by increased perforin mRNA levels and enhanced loss of perforin when transcription was blocked. Degranulation alone was insufficient to provide the activation signal as NK cells lost anticryptococcal activity following treatment with strontium chloride. However, NK cells regained the activity upon prolonged exposure to C. neoformans, which is consistent with activation by the microbe. The enhanced cytotoxicity did not extend to tumor killing since NK cells exposed to C. neoformans failed to kill NK-sensitive tumor targets (K562 cells). These studies demonstrate that there is contact-mediated microbe-specific rearming and activation of microbicidal activity that are necessary for optimal killing of C. neoformans.


Asunto(s)
Cryptococcus neoformans/inmunología , Células Asesinas Naturales/inmunología , Viabilidad Microbiana , Perforina/biosíntesis , Degranulación de la Célula , Línea Celular , Recuento de Colonia Microbiana , Humanos , ARN Mensajero/biosíntesis
5.
J Can Assoc Gastroenterol ; 2(2): 91-97, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31294371

RESUMEN

BACKGROUND AND STUDY AIMS: Malignant-related upper gastrointestinal bleeding (MRUGIB) is difficult to treat by conventional endoscopic methods. We sought to determine the efficacy, safety and mortality associated with the use of TC-325 for the treatment of MUGIB. PATIENTS AND METHODS: This is a multicentre, retrospective study at the University of Calgary and University of Ottawa performed between January 1, 2010, and July 30, 2016. TC-325 use was identified via staff polling, product order forms and endoscopic records review. Once identified, patient charts and online records were examined to identify MRUGIB cases and to assess our primary and secondary endpoints. OUTCOMES: The primary outcome was hemostasis at seven days. Secondary outcomes include immediate hemostasis, early hemostasis, hemostasis at 14 days, 30-day mortality, adverse events related to TC-325 therapy and the need for repeat endoscopic intervention, surgery or transarterial embolization. RESULTS: Twenty-five patients were identified. The median age was 62 years (interquartile range [IQR] 52.5-76), and most were male (64%). TC-325 was the primary treatment modality in 20 patients (80%). Hemostasis was 88%, 89%, 58% and 50% at 24 hours, 72 hours, 7 days and 14 days, respectively. Five patients underwent repeat endoscopy, two patients required surgical intervention, and transarterial embolization was not required. Twelve patients died by 30 days (48%). There were no complications directly attributed to the use of TC-325. CONCLUSIONS: TC-325 is effective for achieving and maintaining hemostasis in patients with malignancy-related upper gastrointestinal bleeding, and most patients do not require additional interventions. The 30-day mortality risk in this group of patients is high.

6.
Clin Nutr ESPEN ; 17: 68-74, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28361750

RESUMEN

BACKGROUND: Malnutrition is an important predictor of morbidity and mortality among cirrhotic patients. Our objectives were to assess protein-calorie malnutrition (PCM) in cirrhotic pre-liver transplant patients and to study the correlation between subjective global assessment (SGA) and other objective measures of malnutrition. METHODS: We recruited pre-liver transplant adult patients at our center between October 2012 and Oct 2015. Nutrition status was assessed via SGA. PCM was assessed by comparing recommended to actual protein and calorie intake. SGA was correlated with body mass index (BMI), dry BMI, handgrip strength by calibrated dynometer (HGS), and mid-arm circumference (MAC). We used non-parametric statistical methods in our analysis. RESULTS: Seventy patients were included in this study. Majority were males (n = 46, 66%) with a median age of 58 years (IQR: 50-61). Moderate to severe malnutrition was prevalent in our cohort (SGA-A: n = 15 (21.4%), SGA-B: n = 30 (42.9%) and SGA-C: n = 25 (35.7%). There was a significant difference in the recommended calories consumed between SGA groups (A 98.5% vs. C 79.2%, P = 0.03). A similar trend was observed for the recommended protein consumed (A 85.4%, C 62.5%; P = 0.09). SGA correlated with BMI (A = 26.4, C = 22.4; P<0.01), Dry BMI (A = 25.9, C = 20.4; P<0.01), HGS (A = 67.0, C = 47.0 PSI; P = 0.03), and MAC (A = 29.5 cm, C = 22.0 cm; P<0.01). HGS and MAC were strongly correlated (Spearman correlation 0.49, P<0.01). CONCLUSIONS: Cirrhotic patients have significant protein-calorie malnutrition. Multiple malnutrition tools including BMI, dry BMI, HGS and MAC were precisely able to assess malnutrition.


Asunto(s)
Cirrosis Hepática/cirugía , Trasplante de Hígado , Evaluación Nutricional , Estado Nutricional , Pruebas en el Punto de Atención , Desnutrición Proteico-Calórica/diagnóstico , Listas de Espera , Adulto , Alberta , Antropometría , Índice de Masa Corporal , Proteínas en la Dieta/administración & dosificación , Ingestión de Energía , Femenino , Fuerza de la Mano , Humanos , Cirrosis Hepática/complicaciones , Cirrosis Hepática/diagnóstico , Masculino , Persona de Mediana Edad , Dinamómetro de Fuerza Muscular , Valor Predictivo de las Pruebas , Estudios Prospectivos , Desnutrición Proteico-Calórica/complicaciones , Desnutrición Proteico-Calórica/fisiopatología , Ingesta Diaria Recomendada , Factores de Riesgo
7.
J Immunol ; 180(11): 7221-9, 2008 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-18490721

RESUMEN

Granulysin is a cytolytic effector molecule used by lymphocytes to kill tumor and microbial cells. Regulation of granulysin production is complex. A significant delay (5 days) following stimulation of CD4(+) T cells with IL-2 occurs before granulysin is produced. Unfortunately, the mechanisms responsible for this delay are unknown. We have recently demonstrated that granulysin-mediated killing of Cryptococcus neoformans by CD4(+) T cells is defective during HIV infection. This is because CD4(+) T cells from HIV-infected patients fail to produce granulysin in response to IL-2 activation. The present studies examined the mechanism of delayed production of granulysin and the mechanism of the defect in HIV patients. We demonstrate that IL-2 initially requires both STAT5 and PI3K activation to increase expression of IL-2Rbeta, produce granulysin, and kill C. neoformans. The increased expression of IL-2Rbeta precedes granulysin, and preventing the increased expression of IL-2Rbeta using small interfering RNA knockdown abrogates granulysin expression. Moreover, following the increased expression of IL-2Rbeta, blocking subsequent signaling by IL-2 using IL-2Rbeta-specific blocking Abs abrogates expression of granulysin. Finally, CD4(+) T cells from HIV-infected patients, who are defective in both STAT5 and PI3K signaling, fail to express IL-2Rbeta and fail to produce granulysin. These results suggest that IL-2 signals via PI3K and STAT5 to increase expression of IL-2Rbeta, which in turn is required for production of granulysin. These results provide a mechanism to explain the "late" production of granulysin during normal T cell responses, as well as for defective granulysin production by CD4(+) T cells in HIV-infected patients.


Asunto(s)
Antígenos de Diferenciación de Linfocitos T/metabolismo , Linfocitos T CD4-Positivos/inmunología , Infecciones por VIH/inmunología , Subunidad beta del Receptor de Interleucina-2/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Factor de Transcripción STAT5/metabolismo , Antígenos de Diferenciación de Linfocitos T/inmunología , Linfocitos T CD4-Positivos/metabolismo , Fosfatidilinositol 3-Quinasa Clase Ib , Cryptococcus neoformans/inmunología , Inhibidores Enzimáticos/farmacología , Infecciones por VIH/metabolismo , Humanos , Interleucina-2/inmunología , Interleucina-2/metabolismo , Subunidad beta del Receptor de Interleucina-2/inmunología , Isoenzimas/antagonistas & inhibidores , Isoenzimas/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3 , Factor de Transcripción STAT5/análisis , Transducción de Señal
8.
J Immunol ; 178(10): 6456-64, 2007 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-17475875

RESUMEN

Previously, NK cells have been reported to kill the opportunistic fungal pathogen Cryptococcus neoformans through a perforin-dependent mechanism; however, the receptor and signaling involved are unknown. In this report we sought to identify the signaling pathways activated and required for direct perforin-mediated killing of microbes. In this study, using the NK-like cell line YT and primary peripheral blood NK cells, it is demonstrated that YT cells kill C. neoformans and that the killing is accompanied by the activation of PI3K. We demonstrate that inhibition of either the catalytic subunit (using a pharmacological inhibitor) or the alpha-regulatory subunit (using small interfering RNA knockdown) of PI3K significantly inhibited the killing of C. neoformans. Downstream of PI3K, ERK1/2 was activated in a PI3K-dependent fashion and was required for cryptococcal killing. Furthermore, we demonstrate that perforin release from YT cells can be detected by 4 h after contact of the YT cells with C. neoformans and that the release of perforin is blocked by pharmacological inhibition of either PI3K or ERK1/2. Defective degranulation is rooted in the inability to polarize perforin-containing granules toward the target. Finally, we demonstrate that PI3K-ERK1/2-dependent signaling is activated and required for the killing of C. neoformans by primary NK cells. Taken together, these data identify a conserved PI3K-ERK1/2 pathway that is used by NK cells during the direct killing of C. neoformans and demonstrate that the pathway is essential in the formation and activation of the microbicidal mechanism.


Asunto(s)
Cryptococcus neoformans/crecimiento & desarrollo , Cryptococcus neoformans/inmunología , Quinasas MAP Reguladas por Señal Extracelular/fisiología , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/microbiología , Sistema de Señalización de MAP Quinasas/inmunología , Glicoproteínas de Membrana/fisiología , Fosfatidilinositol 3-Quinasas/fisiología , Proteínas Citotóxicas Formadoras de Poros/fisiología , Animales , Línea Celular Tumoral , Citotoxicidad Inmunológica , Activación Enzimática/inmunología , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Células Asesinas Naturales/enzimología , Células Asesinas Naturales/metabolismo , Glicoproteínas de Membrana/metabolismo , Ratones , Perforina , Proteínas Citotóxicas Formadoras de Poros/metabolismo
9.
FEMS Yeast Res ; 6(4): 543-57, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16696650

RESUMEN

Murine experimentation has provided many useful tools, including the ability to knockout or over-express genes and to perform experiments that are limited by ethical considerations. Over the past century, mice have imparted valuable insights into the biology of many systems, including human immunity. However, although there are many similarities between the immune response of humans and mice, there are also many differences; none is more prominent than when examining natural killer cell biology. These differences include tissue distribution, effector molecules, receptor repertoire, and cytokine responses, all of which have important implications when extrapolating the studies to the human immune responses to Cryptococcus neoformans.


Asunto(s)
Criptococosis/inmunología , Cryptococcus neoformans/patogenicidad , Células Asesinas Naturales/inmunología , Animales , Modelos Animales de Enfermedad , Humanos , Ratones
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA