[Incidence of COVID-19 in health workers. Work activity and home protection]. / Incidencia de COVID-19 en trabajadores de salud. Actividad laboral y resguardo domiciliario.

Background: The COVID-19 pandemic has had repercussions in the social, economic, psychological and health spheres, for which risk and exposure groups have been identified. Health workers are distinguished from the rest of the population by constant contact with patients carrying the SARS-CoV-2 virus. Objetive: To determine the difference in the incidence of COVID-19 in health workers who remain in work activity and those who shelter at home. Material and methods: Cohort study in health workers from March 2020 to January 2021. Two groups were integrated, the exposed group made up of workers who remained working in the health unit (n = 4650) and the non-exposed group, those who carried out home protection (n = 337). When the groups were integrated, none had a diagnosis of COVID-19, they were followed up for 11 months and when COVID-19 was diagnosed, it was done with a PCR test. Statistical analysis included incidence rate, confidence intervals, Chi square, relative risk, and confidence interval for relative risk. Results: The incidence of COVID-19 in workers in home shelter was 39.8% (95% CI: 34.6-45.0) and in workers who remained in the medical unit 16.0% (95% CI: 14.9-17.1). The relative risk was 0.40 (95% CI: 0.34-0.47) for workers who remained working in the health unit. Conclusion: The incidence of COVID-19 was higher in health workers with home protection than in those who continued with normal activities in the medical unit.

Introducción: la pandemia por COVID-19 ha repercutido en el ámbito social, económico, psicológico y de la salud, por lo que se han identificado grupos de riesgo y de exposición. Los trabajadores de la salud se distinguen del resto de la población por el contacto constante con pacientes portadores del virus SARS-CoV-2. Objetivo: determinar la diferencia de incidencia de COVID-19 en trabajadores de la salud que permanece en actividad laboral y los que se resguardan en domicilio. Material y métodos: estudio de cohorte en trabajadores de la salud de marzo 2020 a enero 2021. Se integraron dos grupos: el grupo expuesto compuesto por trabajadores que permanecieron laborando en la unidad de salud (n = 4650) y el grupo no expuesto, que realizaron resguardo domiciliario (n = 337). Cuando se integraron los grupos ninguno tenía diagnóstico de COVID-19, se siguieron durante 11 meses y cuando se diagnosticó COVID-19 se realizó con prueba de PCR. El análisis estadístico incluyó tasa de incidencia, Intervalos de confianza, Chi cuadrada, riesgo relativo e intervalo de confianza para riesgo relativo. Resultados: la incidencia de COVID-19 de trabajadores en resguardo domiciliario fue de 39.8% (IC95%: 34.6-45.0) y en trabajadores que permanecieron en la unidad médica de 16.0% (IC95%: 14.9-17.1). El riesgo relativo fue de 0.40 (IC95%: 0.34-0.47) para trabajadores que permanecieron laborando en la unidad de salud. Conclusión: la incidencia de COVID-19 fue superior en trabajadores de la salud con resguardo domiciliario que en aquellos que continuaron con actividades normales en la unidad médica.

Overexpression of Cicer arietinum ßIII-Gal but not ßIV-Gal in arabidopsis causes a reduction of cell wall ß-(1,4)-galactan compensated by an increase in homogalacturonan.

In Cicer arietinum, as in several plant species, the ß-galactosidases are encoded by multigene families, although the role of the different proteins is not completely elucidated. Here, we focus in 2 members of this family, ßIII-Gal and ßIV-Gal, with high degree of amino acid sequence identity (81%), but involved in different developmental processes according to previous studies. Our objective is to deepen in the function of these proteins by establishing their substrate specificity and the possible alterations caused in the cell wall polysaccharides when they are overproduced in Arabidopsis thaliana by constructing the 35S::ßIII-Gal and 35S::ßIV-Gal transgenic plants. ßIII-Gal does cause visible alterations of the morphology of the transgenic plant, all related to a decrease in growth at different stages of development. FTIR spectroscopy and immunological studies showed that ßIII-Gal causes changes in the structure of the arabidopsis cell wall polysaccharides, mainly a reduction of the galactan side chains which is compensated by a marked increase in homogalacturonan, which allows us to attribute to galactan a role in the control of the architecture of the cell wall, and therefore in the processes of growth. The 35S::ßIV-Gal plants do not present any phenotypic changes, neither in their morphology nor in their cell walls. In spite of the high sequence homology, our results show different specificity of substrate for these proteins, maybe due to other dissimilar characteristics, such as isoelectric points or the number of N-glycosylation sites, which could determine their enzymatic properties and their distinct action in the cell walls.

Subcellular location of Arabidopsis thaliana subfamily a1 ß-galactosidases and developmental regulation of transcript levels of their coding genes.

The aim of this work is to gain insight into the six members of the a1 subfamily of the ß-galactosidases (BGAL) from Arabidopsis thaliana. First, the subcellular location of all these six BGAL proteins from a1 subfamily has been established in the cell wall by the construction of transgenic plants producing the enhanced green fluorescent protein (eGFP) fused to the BGAL proteins. BGAL12 is also located in the endoplasmic reticulum. Our study of the AtBGAL transcript accumulation along plant development indicated that all AtBGAL transcript appeared in initial stages of development, both dark- and light-grown seedlings, being AtBGAL1, AtBGAL2 and AtBGAL3 transcripts the predominant ones in the latter condition, mainly in the aerial part and with levels decreasing with age. The high accumulation of transcript of AtBGAL4 in basal internodes and in leaves at the end of development, and their strong increase after treatment both with BL and H3BO3 point to an involvement of BGAL4 in cell wall changes leading to the cease of elongation and increased rigidity. The changes of AtBGAL transcript accumulation in relation to different stages and conditions of plant development, suggest that each of the different gene products have a plant-specific function and provides support for the proposed function of the subfamily a1 BGAL in plant cell wall remodelling for cell expansion or for cell response to stress conditions.