15 research outputs found
Reactive Oxygen Species Hydrogen Peroxide Mediates Kaposi's Sarcoma-Associated Herpesvirus Reactivation from Latency
Kaposi's sarcoma-associated herpesvirus (KSHV) establishes a latent
infection in the host following an acute infection. Reactivation from latency
contributes to the development of KSHV-induced malignancies, which include
Kaposi's sarcoma (KS), the most common cancer in untreated AIDS patients,
primary effusion lymphoma and multicentric Castleman's disease. However,
the physiological cues that trigger KSHV reactivation remain unclear. Here, we
show that the reactive oxygen species (ROS) hydrogen peroxide
(H2O2) induces KSHV reactivation from latency through
both autocrine and paracrine signaling. Furthermore, KSHV spontaneous lytic
replication, and KSHV reactivation from latency induced by oxidative stress,
hypoxia, and proinflammatory and proangiogenic cytokines are mediated by
H2O2. Mechanistically, H2O2
induction of KSHV reactivation depends on the activation of mitogen-activated
protein kinase ERK1/2, JNK, and p38 pathways. Significantly,
H2O2 scavengers N-acetyl-L-cysteine (NAC), catalase
and glutathione inhibit KSHV lytic replication in culture. In a mouse model of
KSHV-induced lymphoma, NAC effectively inhibits KSHV lytic replication and
significantly prolongs the lifespan of the mice. These results directly relate
KSHV reactivation to oxidative stress and inflammation, which are physiological
hallmarks of KS patients. The discovery of this novel mechanism of KSHV
reactivation indicates that antioxidants and anti-inflammation drugs could be
promising preventive and therapeutic agents for effectively targeting KSHV
replication and KSHV-related malignancies
El proceso de duelo en psicoterapia de tiempo limitado, evaluado mediante el método del tema central de conflicto relacional (CCRT)
La presente tesis surge del interés de aunar teoría y práctica clínica; como objetivo general se plantea describir el duelo desde un marco referencial psicoanalítico y detectar dicho fenómeno en la práctica clínica, e intervenir con un modelo de psicoterapia psicoanalítica focal y de tiempo limitado. El análisis se realizó con una muestra pequeña de cinco casos estudiados intensivamente con metodología cualitativa y cuantitativa, en donde todos los pacientes estudiados enfrentaron la pérdida postmortem de un ser querido. Los tratamientos psicoterapéuticos se desarrollaron en un encuadre de catorce sesiones y un seguimiento al mes. En cada caso se focalizó en torno a la pérdida y se tomó en cuenta como foco complementario el trabajo de la ansiedad de separación. El duelo que cada uno de los sujetos afrontó fue evaluado de manera clínica y sistemática con el fin de indagar cambios significativos en la elaboración de dicho proceso. Se aplicó el “Método del Tema Central de Conflicto Relacional” (CCRT), en su reformulación alemana denominado: CCRT- LU (Albani, Pokorny, Blazer, Grueninger et al., 2002) adaptado al castellano (López del Hoyo, Ávila-Espada, Pokorny y Albani, 2004). Las principales ventajas que presenta este sistema de categorías son su base empírica y teórica; la estructura lógica y simétrica; y la facilidad de aplicación y de aprendizaje. Los resultados obtenidos muestran de manera concluyente que el Método del Tema Central de Conflicto Relacional (CCRT) se mostró sensible para identificar el cambio de patrón relacional núcleo del conflicto. Aunque no se pueden generalizar las conclusiones y se requiere más investigación, sí aporta un mejor conocimiento de la dinámica del duelo y los cambios que se dieron en esa dinámica fueron detectados por el CCRT. Tras comparar los patrones en las secuencias inicial y final del tratamiento, se pudo comprobar que la psicoterapia psicoanalítica focal y de tiempo limitado aplicada se asoció con cambios en los patrones estructurales del conflicto relacional, y dichos cambios mostraron una evolución favorable del duelo. Finalmente, el valor de este estudio no se limita a los casos estudiados, sino que muestra la importancia de continuar con investigaciones que combinen proceso y resultados, abordando la especificidad de las estructuras emocionales, cognitivas e interpersonales que pueden movilizarse mediante las estrategias de la psicoterapia focal orientada psicoanalíticamente
Aplicación de la Reformulación Alemana del Método del Tema Central de Conflicto Relacional (CCRT-LU) para la Evaluación del Cambio en un Caso de Duelo por Pérdida de la Pareja
The Core Conflictual Relationship Theme Method (CCRT) in its German reformulation named CCRT-LU, and in the Castilian version named CCRT-LU-S, was applied to a single case of grief for the loss of the partner. The objective was to evaluate clinically and systematically changes in the psychotherapeutic process comparing the beginning and the end of the treatment. The method was sensitive to identify in the verbal content of individual psychotherapy sessions the changing patterns of the Core Conflictual Relationship and the central relationship patterns were investigated in order to detect whether there is a pattern, script or outline typical of grief. We worked with focal and brief psychodynamic psychotherapy model of 14 sessions and a follow up after a month. The focus of work in psychotherapy chosen was the elaboration of grief for death of the spouse.Se aplicó el Método del Tema Central de Conflicto Relacional (CCRT) en su reformulación alemana denominada CCRT-LU, utilizando la versión del método en castellano CCRT-LU-S, a un caso único de duelo por pérdida de la pareja. El objetivo fue evaluar clínica y sistemáticamente el cambio en el proceso psicoterapéutico de inicio y fin de la terapia. El método se mostró sensible para identificar el cambio de patrón relacional núcleo de conflicto en el contenido verbal de las sesiones psicoterapéuticas del sujeto, en donde se investigaron los patrones centrales de relación identificables, con el fin de detectar si existe un patrón, guión o esquema típico del duelo. Se trabajó con un modelo de psicoterapia de tiempo limitado y focal desarrollado en 14 sesiones y un seguimiento al mes. El foco de trabajo elegido fue la elaboración del duelo por muerte de la pareja
Simian Immunodeficiency Virus Nef Protein Delays the Progression of CD4(+) T Cells through G(1)/S Phase of the Cell Cycle
Human and simian immunodeficiency virus (HIV and SIV, respectively) infections are characterized by gradual depletion of CD4(+) T cells. The underlying mechanisms of CD4(+) T-cell depletion and HIV and SIV persistence are not fully determined. The Nef protein is expressed early in infection and is necessary for pathogenesis. Nef can cause T-cell activation and downmodulates cell surface signaling molecules. However, the effect of Nef on the cell cycle has not been well characterized. To determine the role of Nef in the cell cycle, we investigated whether the SIV Nef protein can modulate cell proliferation and apoptosis in CD4(+) Jurkat T cells. We developed a CD4(+) Jurkat T-cell line that stably expresses SIV Nef under the control of an inducible promoter. Alterations in cell proliferation were determined by flow cytometry using stable intracytoplasmic fluorescent dye 5- and 6-carboxyfluorescein diacetate succinimidyl ester and bromodeoxyuridine incorporation. Apoptotic cell death was measured by annexin V and propidium iodide staining. Our results demonstrated that SIV Nef inhibited Fas-induced apoptosis in these cells and that the mechanism involved upregulation of the Bcl-2 protein. SIV Nef suppressed CD4(+) T-cell proliferation by inhibiting the progression of cells into S phase of the cell cycle. Suppression involved an upregulation of cyclin-dependent kinase inhibitors p21 and p27 and the downregulation of cyclin D(1) and cyclin A. In summary, inhibition of apoptosis by Nef can lead to persistence of infected cells and can support viral replication. In addition, a Nef-mediated delay in cell cycle progression may contribute to CD4(+) T-cell anergy/depletion seen in HIV and SIV disease
Rapid Onset of Intestinal Epithelial Barrier Dysfunction in Primary Human Immunodeficiency Virus Infection Is Driven by an Imbalance between Immune Response and Mucosal Repair and Regeneration▿
Gut-associated lymphoid tissue (GALT) is an early target for human immunodeficiency virus type 1 (HIV-1) infection and is a site for severe CD4+ T-cell depletion. HIV-associated enteropathy is well-documented in chronic HIV-1 infection. However, the initial host responses to HIV infection in GALT and the early molecular correlates of HIV enteropathogenesis have not been characterized during primary HIV infection. In this study, we provide evidence of viral replication in GALT resident CD4+ T cells and macrophages in primary-stage patients and identify early patterns of host mucosal responses and changes in the molecular microenvironment through gene expression profiling. High levels of viral replication in GALT and marked CD4+ T-cell depletion correlated with decreased expression levels of genes regulating epithelial barrier maintenance and digestive/metabolic functions. These changes coincided with a marked increase in the transcription of immune activation-, inflammation-, and apoptosis-associated genes. Our findings indicate that HIV-induced pathogenesis in GALT emerges at both the molecular and cellular levels prior to seroconversion in primary HIV infection, potentially setting the stage for disease progression by impairing the ability to control viral replication and repair and regenerate intestinal mucosal tissues
Conocimientos de trabajadores de la salud sobre COVID-19, en embarazadas: grupo de especialistas de la Red COVID-19 y Gestación
Determinar el conocimiento de los trabajadores de la salud (TS) sobre diferentes aspectos de la enfermedad COVID-19 en embarazadas. Métodos: Para ello elaboramos una encuesta utilizando la escala de Likert, la cual fue distribuida por las redes sociales durante 8 días, en el mes de abril de 2020. Resultados: La encuesta fue respondida por 617 TS, con edad de predominio en el rango de 51 a 60 años, 33.8 % hombres y mujeres 66.2 %; la mayoría venezolanos 92.2 %; de profesión gineco-obstetras 25.5 %, médicos generales 13.3 %, internistas 7.7 % y perinatólogos 6.1 %, entre otros TS. Más del 70 % de los TS respondió correctamente la pregunta sobre las manifestaciones clínicas del COVID-19 en la gestante, en contraste con la asertividad sobre el aborto, mortalidad materna y prematuridad, la cual fue sólo de 40 % o menos. Este es el primer estudio realizado en Venezuela sobre este tópico.to determine the knowledge of health care workers (HCW) about different aspects of COVID-19 in pregnant women; Methods: we carried out a survey using the Likert scale, which was distributed by social networks for 8 days in April 2020. Results: The survey was answered by 617 HCW, with a predominant age range of 51 to 60 years with 33.8%, women 66.2%, Venezuelan 92. 2%. Obstetrician-gynecologists 25.5%, general practitioners 13.3%, internists 7.7% and perinatologists 6.1%, More than 70% of the TS answered assertively the question about the clinical manifestations of COVID-19 in the pregnant woman in contrast to the assertiveness about abortion, maternal mortality and prematurity which was 40% or less. This is the first study carried out in Venezuela on this subject
Viral Suppression and Immune Restoration in the Gastrointestinal Mucosa of Human Immunodeficiency Virus Type 1-Infected Patients Initiating Therapy during Primary or Chronic Infection
Although the gut-associated lymphoid tissue (GALT) is an important early site for human immunodeficiency virus (HIV) replication and severe CD4(+) T-cell depletion, our understanding is limited about the restoration of the gut mucosal immune system during highly active antiretroviral therapy (HAART). We evaluated the kinetics of viral suppression, CD4(+) T-cell restoration, gene expression, and HIV-specific CD8(+) T-cell responses in longitudinal gastrointestinal biopsy and peripheral blood samples from patients initiating HAART during primary HIV infection (PHI) or chronic HIV infection (CHI) using flow cytometry, real-time PCR, and DNA microarray analysis. Viral suppression was more effective in GALT of PHI patients than CHI patients during HAART. Mucosal CD4(+) T-cell restoration was delayed compared to peripheral blood and independent of the time of HAART initiation. Immunophenotypic analysis showed that repopulating mucosal CD4(+) T cells were predominantly of a memory phenotype and expressed CD11α, α(E)β(7), CCR5, and CXCR4. Incomplete suppression of viral replication in GALT during HAART correlated with increased HIV-specific CD8(+) T-cell responses. DNA microarray analysis revealed that genes involved in inflammation and cell activation were up regulated in patients who did not replenish mucosal CD4(+) T cells efficiently, while expression of genes involved in growth and repair was increased in patients with efficient mucosal CD4(+) T-cell restoration. Our findings suggest that the discordance in CD4(+) T-cell restoration between GALT and peripheral blood during therapy can be attributed to the incomplete viral suppression and increased immune activation and inflammation that may prevent restoration of CD4(+) T cells and the gut microenvironment