Angiotensin Converting Enzyme 2 (ACE2) and COVID-19: An overview of its structure, physiologic role and its involvement in SARS-COV2 infection and therapy

Coronavirus disease of 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is of a great global and national public health concern. Structural studies suggested that the SARS-CoV2 binds through its spike-protein to target cells by interacting with the angiotensin-converting enzyme 2 (ACE2) receptor which is widely expressed in the heart, kidneys, lungs, gut and testes cells. This article reviews the structural and physiologic roles of the human ACE2 and its correlation with the SARS-CoV2 infection and therapy. Evidence has been provided that the amino acids 318-510 of the viral spike protein represent the receptor-binding domain (RBD) which binds to ACE2, especially by means of the critical amino acids at positions 479 and 487, then allowing virus tropism and propagation. ACE2 play a crucial role in the down regulation of the renin-angiotensin-aldosterone system (RAAS). The RAAS ACE-Angiotensin II-AT1R regulatory axis promotes detrimental effects on the host, such as vasoconstriction, generation of reactive oxygen species, inflammation and matrix remodeling. However, the ACE2-Ang 1-7-MasR axis counterbalances the activation of the classical RAS system which inhibits cell growth, inflammation and fibrosis. The ACE2 has a protective effect against organ damage, lung injury and underlying chronic diseases such as hypertension, diabetes, and cardiovascular diseases wich are linked with poor prognosis of healing in patients with COVID-19. On account of the protective effects of ACE2, the design and development of drugs enhancing its activity may become one of the most promising strategies for the therapy of COVID-19 in the future

Contamination des sols par les métaux lourds à partir de mines abandonnées : le cas des mines Aouli-Mibladen-Zeïda au Maroc

Cette étude évalue la contamination métallique des sols au voisinage des mines Aouli, Mibladen et Zeïda abandonnées dans la Haute Moulouya à l’est du Maroc, et s’attache en particulier à l’estimation de la variabilité spatiale de cette contamination et de l’étendue de l’aire contaminée. Les résultats révèlent que les sols proches des sites miniers étudiés et même très éloignés sont fortement contaminés par les métaux lourds – plomb (Pb), zinc (Zn), cuivre (Cu) et cadmium (Cd) ; ils soulignent également une grande variabilité des concentrations non seulement entre les trois sites miniers mais aussi dans un même site minier. L’index de pollution des sols étudiés est généralement élevé même pour les sols échantillonnés en aval à plus de 130 km des sites miniers, alors qu’il est extrêmement élevé en surface des verses de résidus miniers soulignant que ces dernières constituent en l’état des sources pérennes de contamination par les métaux lourds. L’aire insalubre touchée par la pollution métallique issue des sites miniers abandonnés dans la Haute Moulouya est très vaste suite à la dispersion, par les transports éoliens et hydriques, des polluants résiduels des rejets miniers abandonnés sur place. Des mesures de remédiation doivent être prises afin d’immobiliser les polluants et limiter leur transport vers l’environnement

Lead poisoning in children: a case report

Lead colic is a rare cause of abdominal pain. The diagnosis of lead poisoning is most often mentioned in at risk populations (children, psychotic). We report the case of a 2 year old child that was presented for acute abdomen. Abdominal plain radiograph showed multiple intra-colonic metallic particles and suggested lead poisoning diagnosis. Anamnesis found a notion of pica and consumption of peeling paint. Elevated blood lead levels (BLL) confirmed the diagnosis. The lead poisoning is a public health problem especially in children, but its manifestation by a lead colic is rare and could simulate an acute abdomen table.The Pan African Medical Journal 2016;2

ANALYSIS OF SEASONAL VARIATION ON DEGREE OF CONTAMINATION WITH HEAVY METALS IN AARJATE VILLAGE, MOROCCO. AN INDEX APPROACH

Water samples from wells and samples from soil nearby them were taken during dry (June-September 2013) and wet (December 2013, January - February 2014) seasons and concentrations of Cd, Cu, Mn, Ni, Pb and Zn were determined. Contamination Factor for each heavy metal and Nemerow pollution index were calculated showing a decrease in contamination degree from summer to winter for soil and an increase in case of groundwater. Vertical transfer of pollutants from top soil to groundwater was assessed using Hierarchical Cluster Analysis, significant correlations between concentrations and composition of soil being found. In case of Ni, the variables corresponding to the concentrations from soil and groundwater were part of the same cluster, in both seasons, the distribution maps of concentrations confirming the pattern of transfer