70 research outputs found

    The Role of Specific Integrase Strand Transfer Inhibitors (INSTIs) in the Alteration of Oligodendrocyte Maturation and Myelination in Hand

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    Currently, thirty-seven million people are infected with human immunodeficiency virus-1 (HIV-1) worldwide. Thankfully, the development of combined antiretroviral therapy (cART) regimens has decreased mortality and significantly improved the overall quality of life for these patients. However, approximately half of all patients clinically manifest with HIV-associated neurocognitive disorder (HAND), a spectrum of cognitive, motor, and behavioral abnormalities which histologically present as non-specific gliosis, synaptodendritc damage and loss of white matter and myelin. Furthermore, the severity of white matter damage correlates with the length of ART duration. However, almost no studies have been performed to determine how the myelin sheath or the oligodendrocytes that synthesize the sheath are damaged. Thus, we hypothesized that the administration of ART contributed in part to the myelin loss in the CNS of HIV-positive patients. Previously, we have reported that the protease inhibitor class of ART drugs hampered the in vitrodifferentiation of oligodendrocytes. Given that the new US guidelines for treating HIV patients recommends anew class of drugs, the integrasestrand transferinhibitors(INSTIs)as front-line therapy, we examined if two specific INSTIs, Elvitegravir (EVG) and raltegravir (RAL), altered the survival and/or maturation of developing oligodendrocytes in vitroand in vivo. We found that treatment of oligodendrocyte precursor cells (OPCs) with EVG, but not RAL, during differentiation reduced the number of cells positive for immature oligodendrocyte marker galactosylceramide (GalC) and mature oligodendrocyte marker myelin basic protein (MBP) in vitro, as well as the synthesis of myelin proteins. However, neither EVG or RAL induced cell loss or apoptosis, as determined by cell counts and TUNEL assays, suggesting that EVG does not affect OPC viability but instead, inhibits differentiation. EVG-induced oligodendrocyte differentiation deficits could be reversed by pre-treating the cells with a drug that pharmacologically inhibits the phosphorylation of eukaryotic initiation factor 2α(eIF2α) throughthe cellular integrated stress response (ISR). Finally, in vivo,mice receiving EVG/COBI failed to remyelinate the corpus callosum during the three week recovery period following demyelination, after cuprizone treatment. Although EVG/COBI treatment by itself did not cause overt white matter loss in this brain region. Our study demonstrates that EVG, but not RAL, inhibits oligodendrocyte precursor cell differentiation both in vitroand in vivo. Furthermore, EVG may be inhibiting oligodendrocyte precursor cell differentiation though activation of the ISR. Also, we found thatthe effects of EVG on oligodendrocyte differentiation could be attenuated in vitroby inhibiting the ISR. These studies suggest that ART may contribute to cognitive impairment by inhibiting renewal and replacement of oligodendrocytes in adults or development of oligodendrocytes in children. Further, our results suggest an ISR inhibitor might attenuate the negative effect of EVG on the maturation of oligodendrocytes. Our findings also suggest that development of less toxic ART compounds and adjunctive therapies are needed to minimize the side effects of ART on the CNS

    Study of Bryophytic Flora in the Ramsar Wetland of Merja Zerga (North-west of Morocco)

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    The research undertaken in the IBA and Ramsar wetland of Merja Zerga at Moulay Bousselham were interested only in the higher plants. Our study tends then to contribute to enrich the knowledge about the bryophytic flora of this area by filling the gaps in this field. Thus, we carried out a systematic sampling with a stop and a harvest in each encountered bryophyte population. This prospection enabled us to find 26 species of bryophytes including 22 species of mosses belonging to 15 genera and 9 families, and 4 species of liverworts belonging to 3 genera and 3 families. The relative low specificity of this wetland can be explained by the influence of sea spray and the strong anthropic disturbance. A comparison with previous studies allowed us to conclude that 11 species were observed for the first time in the area

    Contribution à la dépollution d’un rejet textile par adsorption sur un coagulant à base du mélange fer/aluminium préparé par électrocoagulation

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    L’industrie textile consomme une grande quantité d’eau, générant ainsi des rejets liquides à charge élevée en divers types de polluants. Ces derniers produisent des effets nocifs sur l’environnement. Ce travail s’intéresse à la dépollution d’un rejet d’une industrie textile, par addition d’un coagulant synthétique à base de fer et d’aluminium, préparé par le procédé d’électrocoagulation. Les résultats ont montré que le traitement de ce rejet par ce coagulant, a permis d’atteindre un rendement d’élimination des matières colorantes de 83.37% en terme de demande chimique en oxygène (DCO).Mots clés: traitement, hydroxyde, coagulation, demande chimique en oxygèn

    Study of the bryological flora at the archaeological site of Chellah, Morocco

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    The Chellah archaeological site in Rabat, listed as a cultural asset since 2012 on UNESCO's World Heritage List, is subject to significant biodeterioration. The aim of this study is to identify the bryophytes that have an important impact on the destruction of the substrate. For this purpose, three prospectionswere carried out in autumn 2014, spring 2015 and winter 2016. The systematic sampling carried out allowed us to identify 20 species of bryophytes belonging to 10 botanical families, of which 4are dominant with 13 species equivalent to 65% of the total. The four families are Pottiaceae, Brachyceciaceae, Funariaceae and Bryaceae; they belong to the class of Muscinae. The liverworts are represented by only 6 species, representing 30% of the total population. Among the 20 species inventoried, 3 are newly observed in the region of Rabat: Entosthodon pulchellus (H. Philib.) Brugués; Dydimodon Fallax Hedw. and Trichostomum crispulum Bruch. When bryophytes settle on substrates, a preliminary soilis initiated to the detriment of the quality of materials and their durability

    Contribution à la dépollution des eaux usées de textile par électrocoagulation et par adsorption sur des composés à base de fer et d’aluminium

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    Les ressources hydriques au monde sont rares et la demande en eau connaît une croissance continue en liaison avec l’évolution démographique et les activités consommatrices en eau, notamment les industries de textiles se voient dans l’obligation de recycler les eaux résiduaires et en particulier celles colorées. Dans ce travail, nous nous sommes intéressés à l’étude de l’élimination des matières organiques et colorantes de deux rejets provenant des industries de textile, un de teinture du tissu de polyester à pH acide et l’autre de teinture du tissu de coton à pH basique. Ces rejets ont été traités de deux manières. La première est par électrocoagulation en utilisant des plaques de fer et/ou d’aluminium. La deuxième est par adsorption sur des composés synthétiques à base de fer et d’aluminium préparés par électrocoagulation. Dans le cas du traitement par le procédé d’électrocoagulation, nous avons constaté que le rendement d’élimination en demande chimique en oxygène (DCO) du rejet de polyester atteint un rendement de DCO de 60% pour un temps de 7 min de réaction. Pour le rejet de coton, le rendement d’élimination, par les plaques de fer/aluminium et l’élimination des matières colorantes, atteint une valeur de 45% en terme de DCO, et ceci en utilisant des plaques d’aluminium seul et de fer/aluminium pour un temps de 12 et 15 min respectivement. Dans le cas du traitement par ajout des coagulants synthétiques préparés au laboratoire, nous pouvons observer que le meilleur rendement d’élimination en DCO du rejet de polyester est obtenu pour une valeur de 48%, pour la faible granulométrie avec une concentration de 5 g/l du composé à base de fer /aluminium. Le rendement d’élimination en DCO du rejet de coton augmente jusqu'à une valeur de 60% avec une concentration de 5 g/l de coagulants appliqués à base d’aluminium seul. Les résultats de la dépollution de ces rejets, ont montré que le rendement d'élimination des matières organiques et colorantes par le procédé d'électrocoagulation est important, et la durée de traitement est courte, mais l'inconvénient de ce procédé c'est la saleté des plaques après chaque utilisation et la fabrication d'une grande quantité des boues par rapport à l’adsorption sur des composés à base de fer /aluminium où on utilise des poudres peu solubles et stables avec un bon rendement d’élimination et faibles quantités de fer et d'aluminium dans le surnageant traité.Keywords: Colorant textile, électrocoagulation, adsorption, dépollution, fer, aluminiu

    Seasonal Variation (Winter vs. Summer) Crustacean Fauna of the Oualidia Lagoon, Morocco

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    The Oualidia lagoon on the Atlantic coast of Morocco provides important ecosystem services such as aquaculture, fisheries, tourism and high ecological and biological productivity. This is the first study to describe the spatio-temporal distribution of the crustacean community and potential controlling factors in the coastal waters of the Oualidia lagoon. Crustaceans were sampled with a Van Veen grab during two surveys in winter and summer 2013, and taxonomic composition and diversity were determined at 43 sampling sites. Of the eighteen crustacean taxa recorded, fifteen were new to Oualidia Lagoon. Sphaeroma serratum was the most abundant species in both seasons. Organic matter and chlorophyll a content were higher, temperature and salinity were lower in winter than in summer. The structure of the crustacean assemblages was characterised by the formation of two main clusters, organised according to a downstream gradient. Canonical Correspondence Analysis (CCA) showed that granulometry, organic matter and salinity strongly influenced the distribution pattern of crustaceans in the lagoon

    Comparative genomic and phylogeographic analysis of Mycobacterium leprae

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    Reductive evolution and massive pseudogene formation have shaped the 3.31-Mb genome of Mycobacterium leprae, an unculturable obligate pathogen that causes leprosy in humans. The complete genome sequence of M. leprae strain Br4923 from Brazil was obtained by conventional methods (6 x coverage), and Illumina resequencing technology was used to obtain the sequences of strains Thai53 (38 x coverage) and NHDP63 (46 x coverage) from Thailand and the United States, respectively. Whole-genome comparisons with the previously sequenced TN strain from India revealed that the four strains share 99.995% sequence identity and differ only in 215 polymorphic sites, mainly SNPs, and by 5 pseudogenes. Sixteen interrelated SNP subtypes were defined by genotyping both extant and extinct strains of M. leprae from around the world. The 16 SNP subtypes showed a strong geographical association that reflects the migration patterns of early humans and trade routes, with the Silk Road linking Europe to China having contributed to the spread of leprosy

    SARS-CoV-2 infects the human kidney and drives fibrosis in kidney organoids

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    Kidney failure is frequently observed during and after COVID-19, but it remains elusive whether this is a direct effect of the virus. Here, we report that SARS-CoV-2 directly infects kidney cells and is associated with increased tubule-interstitial kidney fibrosis in patient autopsy samples. To study direct effects of the virus on the kidney independent of systemic effects of COVID-19, we infected human-induced pluripotent stem-cell-derived kidney organoids with SARS-CoV-2. Single-cell RNA sequencing indicated injury and dedifferentiation of infected cells with activation of profibrotic signaling pathways. Importantly, SARS-CoV-2 infection also led to increased collagen 1 protein expression in organoids. A SARS-CoV-2 protease inhibitor was able to ameliorate the infection of kidney cells by SARS-CoV-2. Our results suggest that SARS-CoV-2 can directly infect kidney cells and induce cell injury with subsequent fibrosis. These data could explain both acute kidney injury in COVID-19 patients and the development of chronic kidney disease in long COVID

    Optimal sizing of wind-photovoltaic hybrid system by the LPSP method

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    A Floristical and Ecological Study of the Medicinal Flora Used by the Local Population of the Haouz-Rehamna Region (Middle Atlantic Morocco-4)

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    To carry out a floristical inventory of plants used in traditional medicine in the HaouzRehamna region, a series of ethnobotanical surveys were conducted during five campaigns (2012–2017) with a representative sample of 1,700 people. These researches are completed by the determination of species collected in the field. It is worth mentioning that, taking into account the recent changes at the international level on taxonomy, the results obtained allowed us to elaborate a catalogue of 415 plant species (bryophytes (2 species); lichens (1), superior mushrooms (1), pteridophytes (4), gymnosperms (8), chlamydosperms (2) and angiosperms (397)) belonging to 291 genera and 99 botanical families, of which nine are the most representative and total 53.49%, namely: Asteraceae (11.33%), Lamiaceae (10.12%), Fabaceae (8.43%), Apiaceae (6.50%), Solanaceae (4.34%), Poaceae (3.86%), Rosaceae (3.37%), Brassicaceae (3.13%) and Cucurbitaceae (2.41%). On the contrary, the other 90 families represent a specific number less than or equal to 1.93%. The data also reflect a high degree of monotypic, where a single species represented 47.48% of the recorded families, and 79.03% of the genera were monotypic. The spontaneous plants occupy the first place with 241 species (58.07%). In addition, the classification by genus showed that the genus Mentha is the most used by its number of species (8 species). Moreover, we noted the use of 12 hybrid species. The chorological analysis revealed the domination of taxa with Mediterranean distribution for spontaneous species. Therophytes (27%) and phanerophytes (23.36%) are the most represented life forms. The results of this study could serve as a basis for future research in the field of floristics and ecology for the conservation of biodiversity
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