Marwan Aguilar

Some of the lineages of SARS-CoV-2, the new coronavirus responsible for COVID-19, exhibit higher transmissibility or partial resistance to antibody-mediated neutralization and were designated by WHO as Variants of Interests (VOIs) or Concern (VOCs). The aim of this study was to monitor the dissemination of VOIs and VOCs in Venezuela from March 2021 to February 2022. A 614 nt genomic fragment was sequenced for the detection of some relevant mutations of these variants. Their presence was confirmed by complete genome sequencing, with a correlation higher than 99% between both methodologies. After the introduction of the Gamma VOC since the beginning of the year 2021, the variants Alpha VOC and Lambda VOI were detected as early as March 2021, at a very low frequency. In contrast, the Mu VOI, detected in May 2021, was able to circulate throughout the country. After the detection of the Delta VOC in June 2021, it became the predominant circulating variant. With the arrival of the Omicron...

Los ensayos de cuantificación de ARN plasmáticos de VIH-1 son importantes para el control de pacientes infectados, así como el monitoreo de la respuesta a la terapia antirretroviral. Por lo tanto, los ensayos comerciales empleados para este propósito deben presentar buena correlación entre si, para dar lugar al manejo terapéutico apropiado. El objetivo del estudio consistió en correlacionar los resultados obtenidos mediante el ensayo de amplificación de señal (bDNA) y PCR en tiempo real (RT-PCR), ambas casas comerciales aprobadas por la FDA y con diferente diana de detección del VIH-1. La validación se realizó con 180 muestras clínicas de pacientes referidos al INHRR. Los resultados fueron comparados con la subpoblación de linfocitos TCD4+ determinados mediante citometría de flujo. El análisis estadístico se realizó empleando el coeficiente de regresión lineal de Pearson (R2) y el valor de contraste de hipótesis con una significancia del 95 %, usando el programa SPSS Statistics v10.0. Se observó una buena correlación entre los ensayos (R2=0.961, p<0.05), siendo la RTPCR más sensible. Las diferencias cuantitativas de carga viral entre las técnicas ensayadas fue menor de 0.5 log10 copias/ml para el 89% de las muestras, y >1 log10 copias/ml solo en dos pacientes, no indicando necesariamente cambio terapéutico. Adicionalmente, se encontró una correlación inversa entre los linfocitos TCD4+ y carga viral del VIH-1 medida por bDNA (R2= 0.20, p<0.05) y RT-PCR (R2= 0.15, p<0.05). Los ensayos evaluados mostraron que ambas técnicas puedes ser empleadas indistintamente para el control de los pacientes VIH positivo

Viruses occupy important place in infectious pathologies and are primary causes of infantile morbidity and mortality, such as respiratory diseases and diarrheas. Being intracellular parasites vaccines have been the most common strategy utilized against them, nevertheless antiviral drugs agents can be useful not only as preventives but therapeutic. In this work we do a general review about antiviral drugs and their principal mechanisms of action at the viral and cellular level, describing the most utilized that already exist until now, and the new ones discovered many of them originated from vegetal species of tropical forest (natural medicine). This constant searching has been done because many of the currently viral drugs are cytotoxic and induce the phenomenon of viral resistance. In this sense the tropical forest has resulted in a source of new compounds with antiviral activity because it is the most prolific biotic community of the planet, having in its biodiversity also the muc...

El Anuario de Mortalidad en Venezuela reporto en el ano 2.008 3.150 muertes infantiles por “sindrome de dificultad respiratoria del recien nacido” y “dificultad respiratoria del recien nacido”. El gen APOE codifica la Apolipoproteina-E que interviene en el metabolismo lipidico incluyendo fosfolipidos, justificando su analisis en relacion a la Enfermedad de Membrana Hialina (EMH). EL gen APOE humano es polimorfico y esta asociado a diversos trastornos del metabolismo lipidico. Por esta razon, se estudio su posible relacion con la sintesis del surfactante pulmonar y por ello con la EMH en neonatos prematuros. Se realizo una investigacion tipo campo experimental, para la cual se tomaron muestras de sangre periferica de 64 neonatos prematuros, pacientes del Hospital Universitario de Caracas, UCV, durante el periodo enero 2008 a diciembre 2009. En el laboratorio de Patologia Molecular, UCV, se realizo aislamiento del ADN genomico de las muestras y mediante la tecnica de RFLP-PCR se genot...

In less than two years since SARS-CoV-2 emerged, the new coronavirus responsible for COVID-19, has accumulated a great number of mutations. Many of these mutations are located in the Spike protein and some of them confer to the virus higher transmissibility or partial resistance to antibody mediated neutralization. Viral variants with such confirmed abilities are designated by WHO as Variants of Concern (VOCs). The aim of this study was to monitor the introduction of variants and VOCs in Venezuela. A small fragment of the viral genome was sequenced for the detection of the most relevant mutations found in VOCs. This approach allowed the detection of Gamma VOC. Its presence was confirmed by complete genome sequencing. The Gamma VOC was detected in Venezuela since January 2021, and in March 2021 was predominant in the East and Central side of the country, representing more than 95% of cases sequenced in all the country in April–May 2021. In addition to the Gamma VOC, other isolates carrying the mutation E484K were also detected. The frequency of this mutation has been increasing worldwide, as shown in a survey of sequences carrying E484K mutation in GISAID, and was detected in Venezuela in many probable cases of reinfection. Complete genome sequencing of these cases allowed us to identify E484K mutation in association with Gamma VOC and other lineages. In conclusion, the strategy adopted in this study is suitable for genomic surveillance of variants for countries lacking robust genome sequencing capacities. In the period studied, Gamma VOC seems to have rapidly become the dominant variant throughout the country.

SARS-CoV-2 is the new coronavirus responsible for COVID-19 disease. The first two cases of COVID-19 were detected in Venezuela on March 13, 2020. The aim of this study was the genetic characterization of Venezuelan SARS-CoV-2 isolates. A total of 7 full SARS-CoV-2 genome sequences were obtained by Sanger sequencing, from patients of different regions of Venezuela, mainly from the beginning of the epidemic. Ten out of 11 isolates (6 complete genomes and 4 partial spike genomic regions) belonged to lineage B, bearing the D614G mutation in the Spike protein. Isolates from the first outbreak that occurred in the Margarita Island harbored an in-frame deletion in its sequence, without amino acids 83–85 of the NSP1 of the ORF1. The search for deletions in 48,635 sequences showed that the NSP1 gene exhibit the highest frequency of deletions along the whole genome. Structural analysis suggests a change in the N-terminal domain with the presence of this deletion. In contrast, isolates circula...

SUMMARY Its genetic dissection, through the identification of quantitative trait loci (QTLs) is an important component of the strategy for the genetic improvement of drought tolerance in local rice cultivars. As a first step within this strategy, we measured the capacity of osmotic adjustment (OA) in 8 local rice varieties (‘Araure 4’, ‘Araure 50’, ‘Cimarron’, ‘Linea 17’, ‘Fonaiap 1’, ‘Fonaiap 2000’ and ‘Venezuela 21’) subjected to water deficit (drought) under glasshouse conditions. The OA values varied between 0.080.6 MPa. ‘Fonaiap 2000’ showed the highest capacity for OA with values ca. 0.5 MPa. In this cultivar, OA was associated with the accumulation of carbohydrates under drought stress. Drought stress symptoms (leaf rolling) appeared later and at more negatives leaf water potemtials (ψh ~ -3.1 MPa) in ‘Fonaiap 2000’ than in the rest of the cultivars studied, indicating that OA is an effective mechanism for maintaining a favorable water status. The values of OA measured in this study are similar to those reported for other cultivars used for mapping QTLs associated to this trait. Thus, ‘Fonaiap 2000’ appears as a good candidate for developing mapping populations for QTL identification and as a potential donor for the improvement of osmotic adjustment capacity in our rice germplasm.

Resumen GHNEIM-HERRERA, Thaura, ROSALES, Arnaldo, MARWAN AGUILAR et al. Identificación de cultivares de arroz con alta capacidad de ajuste osmótico para el mejoramiento genético de la tolerancia a la sequía. Agronomía Trop., dic. 2006, vol. 56, ...

Page 1. Artículo de Revisión - Review Article Revisión sobre el Estado Actual de las Drogas Antivirales Marwan Aguilar y Pedro Michelli. ... Rev Infect Dis 1988, 10 Suppl 3, S490-4. 14. McLeod, GX & Hammer, SM Zidovudine: five years later. Ann Intern Med 1992, 117, 487-501. ...