Randomized clinical trial to assess the impact of the broadly neutralizing HIV-1 monoclonal antibody VRC01 on HIV-1 persistence in individuals on effective ART

Background. Broadly neutralizing monoclonal antibodies (bnMAbs) may promote clearance of HIV-1-expressing cells through antibody-dependent cell-mediated cytotoxicity. We evaluated the effect of the CD4-binding site bnMAb, VRC01, on measures of HIV-1 persistence in chronically infected individuals. Methods. A5342 was a phase 1, randomized, double-blind, placebo-controlled, parallel-arm study. Participants on effective antiretroviral therapy (ART) were randomized to receive 2 infusions of VRC01 (40 mg/kg) at entry and week 3, and 2 infusions of placebo (saline) at weeks 6 and 9; or 2 infusions of placebo at entry and week 3, and 2 infusions of VRC01 at weeks 6 and 9. Results. Infusion of VRC01 was safe and well tolerated. The median fold-change in the cell-associated HIV-1 RNA/DNA ratio from baseline to week 6 was 1.12 and 0.83 for the VRC01 and placebo arms, respectively, with no significant difference between arms (P = .16). There were no significant differences in the proportions with residual plasma viremia ≥1 copies/mL or in phorbol 12-myristate 13-acetate/ionomycin-induced virus production from CD4+ T cells between arms (both P > .05). Conclusions. In individuals with chronic HIV-1 infection on ART, VRC01 infusions were safe and well tolerated but did not affect plasma viremia, cellular HIV-1 RNA/DNA levels, or stimulated virus production from CD4+ T cells

A Middle to Late Miocene Trans-Andean Portal: Geologic Record in the Tatacoa Desert

Integration of several geologic lines of evidence reveals the prevalence of a lowland trans-Andean portal communicating western Amazonia and the westernmost Andes from at least middle Miocene until Pliocene times. Volcanism and crustal shortening built up relief in the southernmost Central and Eastern Cordilleras of Colombia, closing this lowland gap. Independent lines of evidence consist first, of field mapping in the Tatacoa Desert with a coverage area of ∼381 km2, 1,165 km of geological contact traces, 164 structural data points, and 3D aerial digital mapping models. This map documents the beginning of southward propagation of the southernmost tip of the Eastern Cordillera’s west-verging, fold-and-thrust belt between ∼12.2 and 13.7 Ma. Second, a compilation of new and published detrital zircon geochronology in middle Miocene strata of the Tatacoa Desert shows three distinctive age populations: middle Miocene, middle Eocene, and Jurassic; the first two sourced west of the Central Cordillera, the latter in the Magdalena Valley. Similar populations with the three distinctive peaks have now been recovered in western Amazonian middle Miocene strata. These observations, along with published molecular and fossil fish data, suggest that by Serravallian times (∼13 Ma), the Northern Andes were separated from the Central Andes at ∼3°N by a fluvial system that flowed into the Amazon Basin through the Tatacoa Desert. This paleogeographic configuration would be similar to a Western Andean, or Marañon Portal. Late Miocene flattening of the subducting Nazca slab caused the eastward migration of the Miocene volcanic arc, so that starting at ∼4 Ma, large composite volcanoes were built up along the axis of today's Central Cordillera, closing this lowland Andean portal and altering the drainage patterns to resemble a modern configuration.ISSN:2296-646

Consenso colombiano de atención, diagnóstico y manejo de la infección por SARS-COV-2/COVID-19 en establecimientos de atención de la salud Recomendaciones basadas en consenso de expertos e informadas en la evidencia

The “Asociación Colombiana de Infectología” (ACIN) and the “Instituto de Evaluación de Nuevas Tecnologías de la Salud” (IETS) created a task force to develop recommendations for Covid 19 health care diagnosis, management and treatment informed, and based, on evidence. Theses reccomendations are addressed to the health personnel on the Colombian context of health services. © 2020 Asociacion Colombiana de Infectologia. All rights reserved

Constraints to peer scaffolding Limitações na colaboração entre pares

Several studies, usually carried out in settings that are conducive to interaction, demonstrate peers can provide mutual scaffolding effectively. In contrast, this article focuses on constraints to peer scaffolding which, possibly, happened because of participants' demotivating learning environment. Analysis is based on the video and audio recordings of the performance of two beginning Brazilian students carrying out two oral tasks in an EFL class. Task one consists of an information gap and task two, of a communicative drill. The following constraints were identified: 1) the less capable peer's object-regulation, 2) the more capable peer's hindrance to scaffolding, 3) the more capable peer's lack of L2 knowledge. These hindrances can be explained by the students' pervasive and frustrating foreign language learning experience in the Brazilian public school and by the lack of socialization into scaffolding.<br>Vários estudos, geralmente conduzidos em ambientes que favorecem a interação, mostram que colegas podem colaborar mutuamente e de modo eficaz. Entretanto, este trabalho aborda obstáculos à criação desse tipo de andaime que podem ter ocorrido devido ao ambiente desmotivador dos alunos utilizados na pesquisa. A análise é baseada em gravações de áudio e vídeo do desempenho dos alunos em duas atividades orais em uma aula de inglês como língua estrangeira. A atividade um consistiu em uma lacuna de informação e a dois, em um drill comunicativo. Os seguintes obstáculos foram encontrados: 1) a regulação pelo objeto do aluno menos capaz, 2) dificuldades do aluno mais capaz em promover andaimes, 3) falta de conhecimento de inglês do aluno mais capaz. Esses empecilhos podem ser explicados pela experiência onipresente e frustrante desses alunos em aprender inglês na escola pública brasileira e pela sua falta de socialização na colaboração entre pares