Melatonina : bases científicas para su uso en el COVID 19

La Melatonina es una hormona que actúa facilitando la aparición del sueño fisiológico. Además presenta potentes acciónes antiinflamatoria y antioxidante, con lo que ha demostrado ya ser capaz de ejercer efectos muy beneficioso sobre las alteraciones ligadas al envejecimiento que aparecen en el sistema cardiovascular y especialmente en pulmón, donde nuestro grupo ha podido constatar un efecto protector frente a procesos de estrés oxidativo , inflamatorios y de muerte celular programada ( apoptosis).. Aunque no es una sustancia antivírica, sin embargo ha demostrado tener efectos muy positivos en algunos modelos experimentales de infección por vírus disminuyendo la carga viral y también reduciendo la oxidación y la inflamación con lo que atenúa la gravedad de la enfermedad. En el COVID 19 es capaz también de interferir en el proceso infectivo que ocurre a través de los receptores de ACE2 y de EGF pues es capaz de bloquear dichas interacciones con lo que disminuye la viremia. Concretamente reduce la actividad del inflamasoma NLRP3 con lo que bloquea la liberación masiva de citoquinas disminuyendo el proceso inflamatorio lo que supone una mejoría de la evolución de la enfermedad. Por todo ello la melatonina puede desempeñar un importante papel en el tratamiento del COVID 19.Alternate : Melatonin is a hormone that acts facilitating the appearance of physiological sleep It has also a very evident antinflammatory and antioxidant capacities that result in beneficial actions on the aging processes in the cardiovascular system and in the lungs where our group has detected a protective action against oxidative stress , inflammation and apoptosis . Although melatonin is not viricidal by itself in some models of viral infections it has demonstrated its ability to reduce viral load and also inflammation and oxidation, reducing the severity of the disease. In COVID 19 melatonin has been shown to be able to interfere with the infectious process that takes place through ACE2 and EGF receptors being able to block these interactions thus reducing viremia .It is able to block the activation of the NLRP3 inflammasome thus dramatically reducing the massive secretion of cytokines and markedly reducing hyperinflammation and apoptosis leading to a better evolution of the disease .For all these reasons melatonin could play an important role in the treatment of COVID 19.

The role of outdoor and indoor air quality in the spread of SARS-CoV-2: Overview and recommendations by the research group on COVID-19 and particulate matter (RESCOP commission).

There are important questions surrounding the potential contribution of outdoor and indoor air quality in the transmission of SARS-CoV-2 and perpetuation of COVID-19 epidemic waves. Environmental health may be a critical component of COVID-19 prevention. The public health community and health agencies should consider the evolving evidence in their recommendations and statements, and work to issue occupational guidelines. Evidence coming from the current epidemiological and experimental research is expected to add knowledge about virus diffusion, COVID-19 severity in most polluted areas, inter-personal distance requirements and need for wearing face masks in indoor or outdoor environments. The COVID-19 pandemic has highlighted the need for maintaining particulate matter concentrations at low levels for multiple health-related reasons, which may also include the spread of SARS-CoV-2. Indoor environments represent even a more crucial challenge to cope with, as it is easier for the SARS-COV2 to spread, remain vital and infect other subjects in closed spaces in the presence of already infected asymptomatic or mildly symptomatic people. The potential merits of preventive measures, such as CO2 monitoring associated with natural or controlled mechanical ventilation and air purification, for schools, indoor public places (restaurants, offices, hotels, museums, theatres/cinemas etc.) and transportations need to be carefully considered. Hospital settings and nursing/retirement homes as well as emergency rooms, infectious diseases divisions and ambulances represent higher risk indoor environments and may require additional monitoring and specific decontamination strategies based on mechanical ventilation or air purification.

Determination of SARS-CoV-2 RNA in different particulate matter size fractions of outdoor air samples in Madrid during the lockdown.

BACKGROUND: Previous studies described the presence of SARS-CoV-2 in outdoor air particulate matter (PM) in urban areas of northern Italy and USA. The city of Madrid was heavily affected by COVID-19 during March-June 2020. Also, this city usually displays high concentrations of PM under several atmospheric situations. This is mandatory to assess the presence of viral RNA in PM, as an indicator of epidemic recurrence. Our study was aimed at investigating the presence of SARS-CoV-2 RNA in outdoor air samples (on PM10, PM2.5 and PM1). METHODS: Six samples of PM10, PM2.5 and PM1 were collected between the May 4th and 22nd 2020 in Madrid, on quartz fiber filters by using MCV high volume samplers (30 m3 h-1 flow) with three inlets (Digitel DHA-80) for sampling PM10, PM2.5 and PM1. RNA extraction and amplification was performed according to the protocol recently set by Setti et al.2020c in Italy. Up to three highly specific molecular marker genes (N1, N2, and RP) were used to test the presence of SARS-CoV-2 RNA. RESULTS: After RNA extraction and expression measurements of N1, N2 and RP genes from all the collected filters, no presence of SARS-CoV-2 RNA was observed. Control tests to exclude false positive results were successfully accomplished. CONCLUSIONS: No presence of SARS-CoV-2 in quartz fiber filters samplers for PM10, PM2.5 and PM1 fractions was observed in our study carried out in Madrid during the month of May 2020. Nevertheless, the absence of viral genomes could be due to different factors including: limited social interactions and economic activities resulting in reduced circulation of the coronavirus, lower daily PM concentration in outdoor air, as well as to meteorological stability and higher temperature that characterize spring season. Further research should be carried out during winter, in presence of higher viral circulation and daily PM exceedances.