Dengue Virus Type 2: Protein Binding and Active Replication in Human Central Nervous System Cells

An increased number of dengue cases with neurological complications have been reported in recent years. The lack of reliable animal models for dengue has hindered studies on dengue virus (DENV) pathogenesis and cellular tropism in vivo. We further investigate the tropism of DENV for the human central nervous system (CNS), characterizing DENV interactions with cell surface proteins in human CNS cells by virus overlay protein binding assays (VOPBA) and coimmunoprecipitations. In VOPBA, three membrane proteins (60, 70, and 130 kDa) from the gray matter bound the entire virus particle, whereas only a 70 kDa protein bound in white matter. The coimmunoprecipitation assays revealed three proteins from gray matter consistently binding virus particles, one clearly distinguishable protein (~32 kDa) and two less apparent proteins (100 and 130 kDa). Monoclonal anti-NS3 targeted the virus protein in primary cell cultures of human CNS treated with DENV-2, which also stained positive for NeuH, a neuron-specific marker. Thus, our results indicate (1) that DENV-2 exhibited a direct tropism for human neurons and (2) that human neurons sustain an active DENV replication as was demonstrated by the presence of the NS3 viral antigen in primary cultures of these cells treated with DENV-2

Comparative study of senescent Th biomarkers in healthy donors and early arthritis patients. Analysis of VPAC receptors and their influence

Pro-inflammatory CD4+CD28− T cells are characteristic of immunosenescence, but also of several autoimmune/inflammatory diseases. Vasoactive intestinal peptide (VIP) acts as an anti-inflammatory and immunomodulatory mediator on these cells. Our objective was to study the mutual influence between senescent Th cells and VIP axis in early arthritis (EA), comparing with non-EA donors. We characterized the correlation between senescent Th cells and clinic parameters of EA as well as the behavior of senescent Th biomarkers by real-time PCR. Clinical data were systematically recorded at baseline and after 6 months of follow-up. The number of CD4+CD28− T cells measured by sorting is higher in patients who initially meet ACR classification criteria for rheumatoid arthritis (RA) compared to those who were classified as undifferentiated arthritis (UA). A slight positive correlation between EA CD4+CD28− T cells and CRP or ESR and a negative correlation with bone mineral density were found. Th senescent biomarkers in EA CD4+CD28− T cells were similar to donors, however some of them increased after 6 months of follow-up. VPAC receptors were analyzed by real-time PCR and immunofluorescence, and CD4+CD28− T cells showed higher expression of VPAC2 and lower of VPAC1, VPAC2 showing a significant increased expression in EA cells. Sorted CD4+CD28− T cells were in vitro expanded in presence of VIP, wherein VIP increased senescent biomarker CD27, while it diminished CD57 or NKG2 senescent biomarkers. Our study demonstrates for the first time the existence of a link between senescent Th cells and the VIP axis

Evaluación de la susceptibilidad de las células del sistema nervioso central a la infección por el virus del dengue

Tesis (Maestría en Ciencias en Inmunología), Instituto Politécnico Nacional, SEPI, ENCB, 2010, 1 archivo PDF, (63 páginas). tesis.ipn.m

Impact of Calcium-Silicon nanoparticles on flower quality and biochemical characteristics of Lilium under salt stress

Lilium plants are one of the most important and widely distributed ornamental crops in the world. However, these plants are also susceptible to salinity, an environmental factor that is one of the main ones worldwide. Salinity negatively affects the development and productivity of plants, in addition to the fact that it can affect the quality of flowers in ornamental crops. The use of nanotechnology can be a useful tool to counteract the negative effects of salinity, since the application of nanoparticles can function as a biostimulant and induce positive responses against different types of abiotic stress. In the present study, the foliar application of two types and concentrations of calcium-silicon nanoparticles (Ca-Si NPs) (500 and 750 mg L−1) in lilium plants grown with or without stress and under saline stress (30 mM NaCl) was evaluated. The differences between both nanoparticles were the size and content of inorganic residues, where CaSi-1 had a size of 23.29 nm and a content of inorganic residues of 62.0 %, while CaSi-2 had a size of 15.29 nm and a content of inorganic residues of 87.0 %. The results showed that salinity affected the quality of the flowers, as well as the biochemical parameters of the plants. In contrast, the application of Ca-Si NPs induced positive effects on flower quality, improved flower size and fresh biomass. Under salt stress conditions, the application of Ca-Si NPs in lilium improved the biochemical parameters, increased the content of chlorophylls (up to 38.1 %), vitamin C (9.4 %), and antioxidant capacity (19.2-23.8 %) in the leaves. Regarding the stress indicators in the leaves, the hydrogen peroxide (H2O2) was not affected by salinity or by the Ca-Si NPs, while the malondialdehyde (MDA) increased by the application of the NPs, however, under saline stress there were no differences. In lilium flowers without salt stress, both H2O2 and MDA increased by the application of Ca-Si NPs, while under salt stress only MDA increased. The use of Ca-Si NPs can be an alternative to counteract the harmful effects of salinity stress in plants

Seed Priming with Carbon Nanomaterials Improves the Bioactive Compounds of Tomato Plants under Saline Stress

The consumption of food with a high content of bioactive compounds is correlated with the prevention of chronic degenerative diseases. Tomato is a food with exceptional nutraceutical value; however, saline stress severely affects the yield, the quality of fruits, and the agricultural productivity of this crop. Recent studies have shown that seed priming can mitigate or alleviate the negative effects caused by this type of stress. However, the use of carbon nanomaterials (CNMs) in this technique has not been tested for this purpose. In the present study, the effects of tomato seed priming with carbon nanotubes (CNTs) and graphene (GP) (50, 250, and 500 mg L−1) and two controls (not sonicated and sonicated) were evaluated based on the content of photosynthetic pigments in the leaves; the physicochemical parameters of the fruits; and the presence of enzymatic and non-enzymatic antioxidant compounds, carotenoids, and stress biomarkers such as hydrogen peroxide (H2O2) and malondialdehyde (MDA) in the leaves and fruits of tomato plants without saline stress and with saline stress (50 mM NaCl). The results show that saline stress in combination with CNTs and GP increased the content of chlorophylls (9.1–21.7%), ascorbic acid (19.5%), glutathione (≈13%), proteins (9.9–11.9%), and phenols (14.2%) on the leaves. The addition of CNTs and GP increased the activity of enzymes (CAT, APX, GPX, and PAL). Likewise, there was also a slight increase in the content of H2O2 (by 20.5%) and MDA (3.7%) in the leaves. Salinity affected the quality of tomato fruits. The physico-chemical parameters and bioactive compounds in both the stressed and non-stressed tomato plants were modified with the addition of CNTs and GP. Higher contents of total soluble solids (25.9%), phenols (up to 144.85%), flavonoids (up to 37.63%), ascorbic acid (≈28%), and lycopene (12.4–36.2%) were observed. The addition of carbon nanomaterials by seed priming in tomato plants subjected to saline stress modifies the content of bioactive compounds in tomato fruits and improves the antioxidant defense system, suggesting possible protection of the plant from the negative impacts of stress by salinity. However, analysis of the mechanism of action of CNMs through seed priming, in greater depth is suggested, perhaps with the use of omics sciences

Seed Priming with Carbon Nanomaterials to Modify the Germination, Growth, and Antioxidant Status of Tomato Seedlings

The objective of this work was to determine the responses of tomato seed priming with CNMs (carbon nanomaterials), evaluating the changes in germination and biochemical compounds as well as the effect on the growth of tomato seedlings. Five concentrations of CNMs (10, 100, 250, 500, and 1000 mg L−1) were evaluated, as well as an absolute control and a sonicated control. The results showed that seed priming with CNMs did not affect the germination rate of the tomato seeds; however, it negatively affected the vigor variables, such as the root length (up to 39.2%) and hypocotyl biomass (up to 33%). In contrast, the root biomass was increased by the application of both carbon nanotubes and graphene up to 127% in the best case. Seed priming with carbon nanotubes (1000 mg L−1) decreased the plant height (29%), stem diameter (20%), fresh shoot biomass (63%), fresh root biomass (63%), and dry shoot biomass (71%). Seed priming with graphene increased the content of chlorophylls (up to 111%), vitamin C (up to 78%), β-carotene (up to 11 fold), phenols (up to 85%), and flavonoids (up to 45%), as well as the H2O2 content (up to 215%). Carbon nanotubes (CNTs) increased the enzymatic activity (phenylalanine ammonia lyase (PAL), ascorbate peroxidase (APX), glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT). In addition, seed priming with high concentrations of CNMs showed negative effects. Seed priming with carbon nanomaterials can potentially improve the development of the tomato crop; therefore, this technique can be used to induce biostimulation and provides an easy way to apply carbon nanomaterials

DESIGN OF A WEBSITE TO SUPPORT THE TEACHING-LEARNING PROCESS OF GENETICS: Received: 18th February 2024 Revised: 30th April 2024 & 13th May 2024 Accepted: 1st April 2024

Genetics is a science whose teaching-learning process is complex, mainly because it involves abstract concepts about objects invisible to human eyes, such as cells, genes, molecules. The aim of this work was the design of a website for the teaching-learning of genetics by undergraduate \ two aspects: content and user interface. The contents were defined based on an analysis of the skills and knowledge necessary for life sciences professionals. The user interface was designed based on the concept of usability, taking “simplicity” as a guiding criterion. The Genetics website (genetica.abaco2.org) contains resources and tools: infographics, short tests on specific topics, and a simple simulator of the Hardy-Weinberg Law, among others. In addition, short educational texts were designed whereby the student can be introduced to specific topics. The efficiency in learning to read two texts was evaluated in ten groups of undergraduate students (5 of them experimental) by applying a ten-question questionnaire. The experimental groups, which previously read the two educational texts, had 19.8% and 32.2 % more correct answers than the control groups (P<0.01). The Genética website designed is a resource that supports the teaching-learning of specific topics in Genetics that has proven to be useful to undergraduate students and their professors

Clinical and Virological Features of Patients Hospitalized with Different Types of COVID-19 Vaccination in Mexico City

Coronavirus disease 2019 (COVID-19) vaccines effectively protect against severe disease and death. However, the impact of the vaccine used, viral variants, and host factors on disease severity remain poorly understood. This work aimed to compare COVID-19 clinical presentations and outcomes in vaccinated and unvaccinated patients in Mexico City. From March to September 2021, clinical, demographic characteristics, and viral variants were obtained from 1014 individuals with a documented SARS-CoV-2 infection. We compared unvaccinated, partially vaccinated, and fully vaccinated patients, stratifying by age groups. We also fitted multivariate statistical models to evaluate the impact of vaccination status, SARS-CoV-2 lineages, vaccine types, and clinical parameters. Most hospitalized patients were unvaccinated. In patients over 61 years old, mortality was significantly higher in unvaccinated compared to fully vaccinated individuals. In patients aged 31 to 60 years, vaccinated patients were more likely to be outpatients (46%) than unvaccinated individuals (6.1%). We found immune disease and age above 61 years old to be risk factors, while full vaccination was found to be the most protective factor against in-hospital death. This study suggests that vaccination is essential to reduce mortality in a comorbid population such as that of Mexico

HIV-1 drug resistance before initiation or re-initiation of first-line ART in eight regions of Mexico: a sub-nationally representative survey.

BackgroundHIV pretreatment drug resistance (PDR) to NNRTIs in persons initiating ART is increasing in Mexico.ObjectivesTo compare HIV PDR in eight sub-regions of Mexico.Patients and methodsA large PDR survey was implemented in Mexico (September 2017-March 2018) across eight sub-regions. All larger clinics (which provide ART to 90% of all initiators) were included, allocating sample size using the probability-proportional-to-size method. Both antiretroviral-naive and prior antiretroviral-exposed persons were included. HIV PDR levels were estimated from pol Sanger sequences obtained at a WHO-designated laboratory.ResultsA total of 2006 participants were enrolled from 74 clinics. PDR to NNRTIs was higher than to other drug classes (P < 0.0001), crossing the 10% threshold in the North-East, East, South-West and South-East. NNRTI PDR was higher in the South-West (P = 0.02), coinciding with the highest proportion of restarters in this sub-region (14%). We observed higher PDR prevalence to any drug in women compared with men (16.5% versus 12.2%, P = 0.04). After multivariable adjustment, higher NNRTI PDR remained significantly associated with previous antiretroviral exposure in the Centre-North, North-West, South-West and South-East [adjusted OR (aOR): 21, 5, 8 and 25, respectively; P < 0.05]. Genetic network analyses showed high assortativity by sub-region (P < 0.0001), with evidence of drug resistance mutation transmission within local clusters.ConclusionsDiversification of the public health response to HIV drug resistance based on sub-regional characteristics could be considered in Mexico. Higher NNRTI PDR levels were associated with poorer regions, suggesting opportunities to strengthen local HIV programmes. Price and licensing negotiations of drug regimens containing integrase inhibitors are warranted