RESUMO
Aedes aegypti is the main vector of Dengue Virus, carrying the virus during the whole mosquito life post-infection. Few mosquito fitness costs have been associated to the virus infection, thereby allowing for a swift dissemination. In order to diminish the mosquito population, public health agency use persistent chemicals with environmental impact for disease control. Most countries barely use biological controls, if at all. With the purpose of developing novel Dengue control strategies, a detailed understanding of the unexplored virus-vector interactions is urgently needed. Damage induced (through tissue injury or bacterial invasion) DNA duplication (endoreplication) has been described in insects during epithelial cells renewal. Here, we delved into the mosquito midgut tissue ability to synthesize DNA de novo; postulating that Dengue virus infection could trigger a protective endoreplication mechanism in some mosquito cells. We hypothesized that the Aedes aegypti orthologue of the Drosophila melanogaster hindsight gene (not previously annotated in Aedes aegypti transcriptome/genome) is part of the Delta-Notch pathway. The activation of this transcriptional cascade leads to genomic DNA endoreplication. The amplification of the genomic copies of specific genes ultimately limits the viral spreading during infection. Conversely, inhibiting DNA synthesis capacity, hence endoreplication, leads to a higher viral replication.
RESUMO
Priming is the conceptual term defining memory phenomenon in innate immune response. Numerous examples of enhanced secondary immune response have been described in diverse taxa of invertebrates; which naturally lacks memory response. In mosquitoes, a previous non-lethal challenge with some specific pathogens modify their immune response against the same microorganism; developing an improved antimicrobial reaction. In this work, we explore the ability of Aedes aegypti to mount a higher antiviral response upon a second oral DENV challenge. When previously challenged with inactive virus, we observed that the posterior infection showed a diminished number of DENV infectious particles in midguts and carcasses. In challenged tissues, we detected higher de novo midgut DNA synthesis than control group, as determined by DNA incorporation of 5-bromo-2-deoxyuridine. We demonstrated that inactive DENV particle are capable to induce DNA synthesis levels comparable to infective DENV. We considered the Drosophila melanogaster hindsight and Delta-Notch mosquitoes orthologues as potential de novo DNA synthesis pathway components (as observed in fly oocyte development and midgut tissue renewal). We showed that Aedes aegypti hindsight transcript relative expression levels were higher than control during DENV infection and inactive DENV particle alimentation. Also, Aedes aegypti second challenge with active DENV induced higher hindsight, Delta and Notch transcriptions in the primed mosquitoes (compared with the primary infection levels). Considering that the mosquito de novo DNA synthesis is concomitant to viral particle reduction, this finding opens a new perspective on the mechanisms underlying the vector antiviral immune response and the effector molecules involved.
Assuntos
Aedes/imunologia , Vírus da Dengue/fisiologia , Dengue/imunologia , Intestinos/virologia , Imunidade Adaptativa , Aedes/virologia , Animais , DNA , Humanos , Imunização Secundária , Memória Imunológica , Mosquitos Vetores , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Carga Viral , Vírion/metabolismoRESUMO
Introducción: La dificultad de completar un protocolo de weaning convencional, en el paciente obeso mórbido, establece una estadía prolongada en ventilación mecánica (VMI) y en UCI. Se propone el protocolo de weaning Fast-Fat, en pacientes obesos mórbidos, con insuficiencia respiratoria aguda (IRA), utilizando VMNI posextubación inmediata. Metodología: A fin de evaluar el protocolo de weaning en relación a: mortalidad a los 28 días, días de VMI, días UCI, necesidad de reintubación, número de traqueotomías (TQ) realizadas, y días de VMNI; y a la vez, comparar los días de VMI y días UCI en relación a protocolo de weaning convencional; se realizó un estudio de corte transversal con reclutamiento prospectivo, entre mayo de 2010 y julio de 2011, incluyendo en el protocolo, al total de pacientes que estaban en condiciones de iniciar un proceso de weaning con antecedentes de obesidad (IMC >35) e IRA. Si completan de manera exitosa la PVE de 1 hora en VMI, y cumplen criterios de extubación, pasan directamente VMNI. Se incluyeron 30 pacientes adultos, con edades de 59,1 +/- 12,7; 50 por ciento varones, con APACHE II 16,3 (rango 7 a 33), que fueron comparados con una cohorte retrospectiva de 18 pacientes similares características. Resultados: Nuestro estudio no presentó mortalidad a los 28 días, ningún paciente requirió reintubación, ni TQ; con 2,1 +/- 1,1 días en VMNI. Con estadía en VMI 5,7 +/- 2,4 días, versus el grupo comparativo sin aplicación de protocolo de 14,4 +/- 6 días (p<0,05). Con estadía en UCI de 21,4 +/- 5,6 días sin protocolo versus 7,6 +/- 2,48 días (p <0,05) con protocolo de weaning. Conclusión: Es posible disminuir de manera significativa, la estadía en VMI, en UCI, con la aplicación de este protocolo de weaning rápido utilizando VMNI posextubación en pacientes obesos mórbidos; de manera eficaz y segura.
Introduction: The difficulty of completing a standard weaning protocol in morbid obese patient, provides an extended stay on invasive mechanical ventilation (MV) and in ICU. Intends a protocol of weaning Fat-Fast, in morbidly obese patients and acute respiratory failure (ARF) using noninvasive ventilation (NIV) immediately after extubation. Methodology: to assess the weaning protocol in relation to: mortality at 28 days, days in IMV, ICU days, need for reintubation, n° of tracheotomies performed; and also, compare IMV days, and ICU days in relation to conventional weaning protocol. We conducted a cross sectional study with prospective recruitment between May 2010and July 2011, including all patients who were able to initiate a process of weaning, with clinical history obesity (BMI > 35) and ARF. If completed successfully the designed spontaneous ventilatory trial for 1 hour in the IMV, and meet extubation criteria, pass directly to the NIV. We included 30 adult patients, aged 59.1 +/- 12.7, 50 percent male, and with APACHE II 16.3 (range 7 to 33), were compared with a retrospective cohort of 18 patients with similar characteristics. Results: no mortality at 28 days, no patient requires reintubation or TQ; with an average of 2.1 +/- 1.1 days in the NIV. IMV stay was 5.7 +/- 2.4 days with Fast-Fat, versus conventional weaning protocol was 14.4 +/- 6 days (p < 0, 05). ICU stay with the conventional protocol was 21.4 +/- 5.6 versus 7.6 +/- 2.48 days (p<0, 05) with Fast Fat. Conclusion: With the application of this rapid weaning protocol, using postextubation NIV in morbidly obese patients, it is possible to decrease effectively and safely the IMV and ICU stay, significantly.
Assuntos
Humanos , Masculino , Adulto , Feminino , Desmame do Respirador/métodos , Insuficiência Respiratória/terapia , Obesidade Mórbida/complicações , Respiração Artificial , Doença Aguda , Extubação , Protocolos Clínicos , Estudos Transversais , Unidades de Terapia Intensiva , Insuficiência Respiratória/complicações , Tempo de Internação , Estudos Prospectivos , Fatores de TempoRESUMO
Introducción: La VMNI se utiliza en una gran variedad de condiciones clínicas, siendo necesario, determinar las variables que condicionan el éxito o fracaso de la VMNI en insuficiencia respiratoria aguda (IRA) tipo I y II, y en falla postextubación (FPEXT). Material y método: A fin de analizar las variables responsables del éxito o fracaso de la VMNI en IRA, y desarrollar un modelo predictivo precoz, del éxito de la VMNI; se analizaron 102 pacientes (edad 56,5 +/- 17,2 años, 64 por ciento hombres, con APACHE II: 14,7 +/-6,5); que utilizaron VMNI, en modalidad Bilevel. Se registraron parámetros demográficos, clínicos y gasométricos, basales y a la hora de inicio de la VMNI. Los datos fueron analizados con regresión lineal, tablas de contigencia, pruebas de normalidad Shapiro Wilks, Cramer Von Mises, Durbin-Watson; razón de verosimilitud, Chi cuadrado y árbol de clasificación. Resultados: La aplicación de la VMNI fue exitosa en 82,4 por ciento de los casos. El éxito no está supeditado al tipo de IRA; puesto que tanto en IRA I y II es >80 por ciento de los casos, con una leve tendencia hacia mejores resultados con VMNI en IRA tipo II (p= 0,93). En FPEXT,y en IRA, se logra evitar la intubación, en el 78 por ciento y 87 por ciento respectivamente. Se observan 6 variables, que mediante un flujograma propuesto, permiten predecir con el 96 por ciento de exactitud, el éxito o fracaso de la VMNI, en ambos tipos de IRA y en FPEXT. Además se aporta con un modelo que permite calcular la FiO2 administrada en equipos de VMNI sin blender de O2 (p = 0.09). Conclusiones: La VMNI es una herramienta eficaz en el manejo precoz de ambos tipos de IRA y FPEXT, evitando la conexión a VMI.No se encontraron variables individuales, que logren predecir el éxito o fracaso de la VMNI de manera significativa en ambos tipos de IRA, como tampoco en FPEXT. Sin embargo, la combinación de 6 variables permite, a través del flujograma propuesto...
Noninvasive ventilation (NIV) is used in a variety of clinical conditions, it is important to determine the variables that decide the success or failure of NIV in Acute Respiratory Failure (ARF) type I and II, and also in failure after extubation (FAE). Material and Methods: The aims of this study were asses with the variables in the success or failure of NIV in ARF, and develop an early prediction model of success or failure in the NIV. We analyzed 102 patients (age 56, 5 +/- 17,2 years; 64 percent men; APACHE II 14,7 +/- 6,5) who used NIV in bilevel mode. We recorded demographic, clinical and blood gas prior and an hour later, to the initiation of the NIV. Data were analyzed whit linear regression, contingency tables, Shapiro Wilks normality tests, Cramer Von Mises, Durbin-Watson, like hood ratio, chi square and classification tree. Results: the application of NIV was successful in 82, 4 percent of cases. The success does not depend of the type of ARF, since both of ARF have a success in >80 percent of cases, with a slight trend towards better outcome whit NIV to treat ARF type II(p=0,93). In FAE and in both ARF, intubations were avoided in 78 percent and 87 percent respectively. Six variables are obtained, through a proposed flow chart, whit 96 percent of accuracy, allows predicting success of NIV, in both types of ARF and in FAE. In addition, we delivered a new model that calculates the FiO2administrated in ventilators without an O2 blender (p =0.09). Conclusion: The noninvasive ventilator assistant is an effective tool in early management of both types of ARF, avoiding the connection to invasive ventilation, or reintubation. There were no isolated variables that are able to predict the success or failure of NIV significantly in both types of ARF, nor in FAE. However, the combination of 6 variables can, through the proposed flow chart, anticipates the evolution of the patients in the NIV.