New insights into the antiviral activity of nordihydroguaiaretic acid: Inhibition of dengue virus serotype 1 replication.

BACKGROUND: Dengue virus (DENV) is considered one of the most important pathogens in the world causing 390 million infections each year. Currently, the development of vaccines against DENV presents some shortcomings and there is no antiviral therapy available for its infection. An important challenge is that both treatments and vaccines must be effective against all four DENV serotypes. Nordihydroguaiaretic acid (NDGA), isolated from Larrea divaricata Cav. (Zygophyllaceae) has shown a significant inhibitory effect on a broad spectrum of viruses, including DENV serotypes 2 and 4. PURPOSE: We evaluated the in vitro virucidal and antiviral activity of NDGA on DENV serotype 1 (DENV1), including the study of its mechanism of action, to provide more evidence on its antiviral activity. METHODS: The viability of viral particles was quantified by the plaque-forming unit reduction method. NDGA effects on DENV1 genome and viral proteins were evaluated by qPCR and immunofluorescence, respectively. Lysosomotropic activity was assayed using acridine orange and neutral red dyes. RESULTS: NDGA showed in vitro virucidal and antiviral activity against DENV1. The antiviral effect would be effective within the first 2 h after viral internalization, when the uncoating process takes place. In addition, we determined by qPCR that NDGA decreases the amount of intracellular RNA of DENV1 and, by immunofluorescence, the number of cells infected. These results indicate that the antiviral effect of NDGA would have an intracellular mechanism of action, which is consistent with its ability to be incorporated into host cells. Considering the inhibitory activity of NDGA on the cellular lipid metabolism, we compared the antiviral effect of two inhibitors acting on two different pathways of this type of metabolism: 1) resveratrol that inhibits the sterol regulatory element of binding proteins, and 2) caffeic acid that inhibits the 5-lipoxygenase (5-LOX) enzyme. Only caffeic acid produced an inhibitory effect on DENV1 infection. We studied the lysosomotropic activity of NDGA on host cells and found, for the first time, that this compound inhibited the acidification of cell vesicles which would prevent DENV1 uncoating process. CONCLUSION: The present work contributes to the knowledge of NDGA activity on DENV. We describe its activity on DENV1, a serotype different to those that have been already reported. Moreover, we provide evidence on which stage/s of the viral replication cycle NDGA exerts its effects. We suggest that the mechanism of action of NDGA on DENV1 is related to its lysosomotropic effect, which inhibits the viral uncoating process.

Roughness of retinal layers in Alzheimer's disease.

There is growing evidence that thinned retinal regions are interspersed with thickened regions in all retinal layers of patients with Alzheimer's disease (AD), causing roughness to appear on layer thickness maps. The hypothesis is that roughness of retinal layers, assessed by the fractal dimension (FD) of their thickness maps, is an early biomarker of AD. Ten retinal layers have been studied in macular volumes of optical coherence tomography from 24 healthy volunteers and 19 patients with mild AD (Mini-Mental State Examination 23.42 ± 3.11). Results show that FD of retinal layers is greater in the AD group, the differences being statistically significant (p < 0.05). Correlation of layer FD with cognitive score, visual acuity and age reach statistical significance at 7 layers. Nearly all (44 out of 45) FD correlations among layers are positive and half of them reached statistical significance (p < 0.05). Factor analysis unveiled two independent factors identified as the dysregulation of the choroidal vascular network and the retinal inflammatory process. Conclusions: surface roughness is a holistic feature of retinal layers that can be assessed by the FD of their thickness maps and it is an early biomarker of AD.

Planning to reduce 30-day adverse events after discharge of frail elderly patients with acute heart failure: design and rationale for the DEED FRAIL-AHF trial. / Planificación del alta desde urgencias para reducir eventos adversos a 30 días en pacientes mayores frágiles con insuficiencia cardiaca aguda: diseño y justificación del ensayo clínico DEED FRAIL-AHF.

OBJECTIVES: To demonstrate the efficacy of a system for comprehensive care transfer (Multilevel Guided Discharge Plan [MGDP]) for frail older patients diagnosed with acute heart failure (AHF) and to validate the results of MGDP implementation under real clinical conditions. The MGDP seeks to reduce the number of adverse outcomes within 30 days of emergency department (ED) discharge. MATERIAL AND METHODS: We will enroll frail patients over the age of 70 years discharged home from the ED with a main diagnosis of AHF. The MGDP includes the following components: 1) a checklist of clinical recommendations and resource activations, 2) scheduling of an early follow-up visit, 3) transfer of information to the primary care doctor, and 4) written instructions for the patient. Phase 1 of the study will be a matched-pair cluster-randomized controlled trial. Ten EDs will be randomly assigned to the intervention group and 10 to the control group. Each group will enroll 480 patients, and the outcomes will be compared between groups. Phase 2 will be a quasi-experimental study of the intervention in 300 new patients enrolled by the same 20 EDs. The outcomes will be compared to those for each Phase-1 group. The main endpoint at 30 days will be a composite of 2 outcomes: revisits to an ED and/for hospitalization for AHF or cardiovascular death. CONCLUSION: The study will assess the efficacy and feasibility of comprehensive MGDP transfer of care for frail older AHF patients discharged home.

OBJETIVO: Demostrar la eficacia de una intervención integral en la transición de cuidados (Plan de Alta Guiado Multinivel, PAGM) para disminuir eventos adversos a 30 días en ancianos frágiles con insuficiencia cardiaca aguda (ICA) dados de alta desde servicios de urgencias (SU) y validar los resultados de dicha intervención en condiciones reales. METODO: Se seleccionarán pacientes 70 años frágiles con diagnóstico principal de ICA dados del alta a su domicilio desde SU. La intervención consistirá en aplicar un PAGM: 1) lista de verificación sobre recomendaciones clínicas y activación de recursos; 2) programación de visita precoz; 3) transmisión de información a atención primaria; 4) hoja de instrucciones al paciente por escrito. Fase 1: ensayo clínico con asignación al azar por conglomerados emparejado. Se asignará de forma aleatoria 10 SU (N = 480) al grupo de intervención y 10 SU (N = 480) al grupo de control. Se compararán los resultados entre grupo de intervención y control. Fase 2: estudio cuasi-experimental. Se realizará la intervención en los 20 SU (N = 300). Se comparará los resultados entre la fase 1 y 2 del grupo de intervención y entre la fase 1 y 2 del grupo de control. La variable principal de resultado es compuesta (revisita a urgencias u hospitalización por ICA o mortalidad de origen cardiovascular) a los 30 días del alta. CONCLUSIONES: El estudio valorará la eficacia y factibilidad de una intervención integral en la transición de cuidados para reducir resultados adversos a 30 días en ancianos frágiles con ICA dados de alta desde los SU.

[Microbicides for preventing sexually transmitted infections: Current status and strategies for preclinical evaluation of new candidates]. / Microbicidas para la prevención de infecciones de transmisión sexual: estado actual y estrategias para la evaluación preclínica de nuevos candidatos.

Microbicides are a new tool, still under investigation, which could help prevent infection by the human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs). Increasing evidence shows that the complexity of sexual transmission of viral pathogens requires the identification of compounds able to block the early events during the cycle of viral infection. In this manuscript we provide a comprehensive review of the different microbicide strategies that have been studied or are currently being considered for STI prevention, particularly emphasizing those having the potential to block HIV infection. The manuscript also reviews the complex process that is required to conduct future clinical studies in humans and concludes with a brief discussion of the strategies that could be part of the immediate future in microbicide research.

Microbicidas para la prevención de infecciones de transmisión sexual: estado actual y estrategias para la evaluación preclínica de nuevos candidatos. / [Microbicides for preventing sexually transmitted infections: Current status and strategies for preclinical evaluation of new candidates].

Microbicides are a new tool, still under investigation, which could help prevent infection by the human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs). Increasing evidence shows that the complexity of sexual transmission of viral pathogens requires the identification of compounds able to block the early events during the cycle of viral infection. In this manuscript we provide a comprehensive review of the different microbicide strategies that have been studied or are currently being considered for STI prevention, particularly emphasizing those having the potential to block HIV infection. The manuscript also reviews the complex process that is required to conduct future clinical studies in humans and concludes with a brief discussion of the strategies that could be part of the immediate future in microbicide research.

Zinc acetate/carrageenan gels exhibit potent activity in vivo against high-dose herpes simplex virus 2 vaginal and rectal challenge.

Topical microbicides that block the sexual transmission of HIV and herpes simplex virus 2 (HSV-2) are desperately needed to reduce the incidence of HIV infections worldwide. Previously we completed phase 3 testing of the carrageenan-based gel Carraguard. Although the trial did not show that Carraguard is effective in preventing HIV transmission during vaginal sex, it did show that Carraguard is safe when used weekly for up to 2 years. Moreover, Carraguard has in vitro activity against human papillomavirus (HPV) and HSV-2 and favorable physical and rheological properties, which makes it a useful vehicle to deliver antiviral agents such as zinc acetate. To that end, we previously reported that a prototype zinc acetate carrageenan gel protects macaques against vaginal challenge with combined simian-human immunodeficiency virus reverse transcriptase (SHIV-RT). Herein, we report the safety and efficacy of a series of zinc acetate and/or carrageenan gels. The gels protected mice (75 to 85% survival; P < 0.001) against high-dose (10(6)-PFU) HSV-2 vaginal or rectal challenge. In contrast, zinc acetate formulated in HEC (hydroxyethylcellulose; or the Universal Placebo) failed to protect mice against the high-dose vaginal HSV-2 challenge (similar to aqueous zinc acetate solution and the placebo controls). The gels were found to be effective spreading gels, exhibited limited toxicity in vitro, caused minimal damage to the architecture of the cervicovaginal and rectal mucosae in vivo, and induced no increased susceptibility to HSV-2 infection in a mouse model. Our results provide a strong rationale to further optimize and evaluate the zinc acetate/carrageenan gels for their ability to block the sexual transmission of HIV and HSV-2.

Target preparation for DNA microarray hybridization.

DNA microarrays are widely used to analyze genome-wide gene expression patterns and to study genotypic variations. They are miniaturized collections of thousands of DNA fragments arrayed on a surface. Based on nucleic acid complementary binding, they serve as a tool to interrogate complex populations of nucleic acids for abundance or binding affinity of particular sequences. Before a nucleic acid (target) can be used for hybridization to the probes of a microarray, it needs to be extracted from the tissue and labeled. Frequently, it also needs to be amplified to increase detection sensitivity. During a hybridization process, labeled target molecules with sequences complementary to the probes are captured quantitatively. Subsequently, a reader measures the amount of label on each probe. To generate accurate and informative data, one of the most critical aspects of these experiments is the quality of both the isolated and the labeled nucleic acid samples. This chapter describes detailed procedures for the preparation of labeled RNA samples for DNA microarray analysis.

Diverticulitis aguda de sigma: valor de la ecografía como test diagnóstico inicial / Acute diverticulitis of the sigmoid colon: value of ultrasound as an initial diagnostic test

Objetivo: Comprobar el valor de la ecografía como método diagnóstico inicial en la diverticulitis aguda.Material y métodos: Se realizó ecografía en 76 pacientes con el diagnóstico clínico de diverticulitis aguda de sigma. El diagnóstico final se basó en el curso clínico en todos los casos, la TC (n = 46), el examen histopatológico de la pieza quirúrgica (n = 10), la colonoscopia (n = 4) y el enema opaco (n = 2). El criterio diagnóstico ecográfico fue el engrosamiento mural del sigma > de 4 mm y la presencia de al menos uno de los siguientes hallazgos: divertículos, flemón o absceso.El diagnóstico por TC se basó en dos hallazgos necesarios: engrosamiento de sigma > de 4 mm y la inflamación de la grasa pericólica.Resultados: El diagnóstico final fue diverticulitis aguda (n = 52), otro diagnóstico (n = 18) o desconocido (n = 6). La sensibilidad de la ecografía y la TC fue 81 por ciento y 94 por ciento respectivamente, y la especificidad 79 por ciento y 83 por ciento respectivamente. De los 10 falsos negativos de la ecografía siete correspondieron a diverticulitis simples y tres a diverticulitis complicadas (dos con absceso y una con neumoperitoneo). La TC diagnosticó correctamente ocho de estos casos, presentando dos falsos negativos ante diverticulitis leves.Conclusión: La ecografía resulta un buen test en el diagnóstico inicial de la diverticulitis aguda de sigma. Se debe realizar TC ante una ecografía no diagnóstica o negativa con una alta sospecha clínica de diverticulitis, y tambien ante la posibilidad de una diverticulitis complicada (AU)