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  1. Article: Unraveling the Underlying Molecular Mechanism of 'Silent Hypoxia' in COVID-19 Patients Suggests a Central Role for Angiotensin II Modulation of the AT1R-Hypoxia-Inducible Factor Signaling Pathway.

    Devaux, Christian Albert / Lagier, Jean-Christophe

    Journal of clinical medicine

    2023  Volume 12, Issue 6

    Abstract: A few days after being infected with SARS-CoV-2, a fraction of people remain asymptomatic but suffer from a decrease in arterial oxygen saturation in the absence of apparent dyspnea. In light of our clinical investigation on the modulation of molecules ... ...

    Abstract A few days after being infected with SARS-CoV-2, a fraction of people remain asymptomatic but suffer from a decrease in arterial oxygen saturation in the absence of apparent dyspnea. In light of our clinical investigation on the modulation of molecules belonging to the renin angiotensin system (RAS) in COVID-19 patients, we propose a model that explains 'silent hypoxia'. The RAS imbalance caused by SARS-CoV-2 results in an accumulation of angiotensin 2 (Ang II), which activates the angiotensin 2 type 1 receptor (AT1R) and triggers a harmful cascade of intracellular signals leading to the nuclear translocation of the hypoxia-inducible factor (HIF)-1α. HIF-1α transactivates many genes including the angiotensin-converting enzyme 1 (ACE1), while at the same time, ACE2 is downregulated. A growing number of cells is maintained in a hypoxic condition that is self-sustained by the presence of the virus and the ACE1/ACE2 ratio imbalance. This is associated with a progressive worsening of the patient's biological parameters including decreased oxygen saturation, without further clinical manifestations. When too many cells activate the Ang II-AT1R-HIF-1α axis, there is a 'hypoxic spillover', which marks the tipping point between 'silent' and symptomatic hypoxia in the patient. Immediate ventilation is required to prevent the 'hypoxic spillover'.
    Language English
    Publishing date 2023-03-22
    Publishing country Switzerland
    Document type Journal Article ; Review
    ZDB-ID 2662592-1
    ISSN 2077-0383
    ISSN 2077-0383
    DOI 10.3390/jcm12062445
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Unraveling the Underlying Molecular Mechanism of ‘Silent Hypoxia’ in COVID-19 Patients Suggests a Central Role for Angiotensin II Modulation of the AT1R-Hypoxia-Inducible Factor Signaling Pathway

    Christian Albert Devaux / Jean-Christophe Lagier

    Journal of Clinical Medicine, Vol 12, Iss 2445, p

    2023  Volume 2445

    Abstract: A few days after being infected with SARS-CoV-2, a fraction of people remain asymptomatic but suffer from a decrease in arterial oxygen saturation in the absence of apparent dyspnea. In light of our clinical investigation on the modulation of molecules ... ...

    Abstract A few days after being infected with SARS-CoV-2, a fraction of people remain asymptomatic but suffer from a decrease in arterial oxygen saturation in the absence of apparent dyspnea. In light of our clinical investigation on the modulation of molecules belonging to the renin angiotensin system (RAS) in COVID-19 patients, we propose a model that explains ‘silent hypoxia’. The RAS imbalance caused by SARS-CoV-2 results in an accumulation of angiotensin 2 (Ang II), which activates the angiotensin 2 type 1 receptor (AT1R) and triggers a harmful cascade of intracellular signals leading to the nuclear translocation of the hypoxia-inducible factor (HIF)-1α. HIF-1α transactivates many genes including the angiotensin-converting enzyme 1 (ACE1), while at the same time, ACE2 is downregulated. A growing number of cells is maintained in a hypoxic condition that is self-sustained by the presence of the virus and the ACE1/ACE2 ratio imbalance. This is associated with a progressive worsening of the patient’s biological parameters including decreased oxygen saturation, without further clinical manifestations. When too many cells activate the Ang II-AT1R-HIF-1α axis, there is a ‘hypoxic spillover’, which marks the tipping point between ‘silent’ and symptomatic hypoxia in the patient. Immediate ventilation is required to prevent the ‘hypoxic spillover’.
    Keywords COVID-19 ; silent hypoxia ; angiotensin II ; ACE2 ; renin-angiotensin system ; AT1R ; Medicine ; R
    Subject code 610
    Language English
    Publishing date 2023-03-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article: Conduite à tenir devant une morsure ou une griffure animale.

    Melenotte, Cléa / Lagier, Jean-Christophe

    La Revue du praticien

    2019  Volume 69, Issue 3, Page(s) 324–327

    Title translation Management of an c or scratch.
    Language French
    Publishing date 2019-05-17
    Publishing country France
    Document type Journal Article
    ZDB-ID 205365-2
    ISSN 2101-017X ; 0035-2640
    ISSN (online) 2101-017X
    ISSN 0035-2640
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Fecal microbiota transplantation for antibiotic resistant bacteria decolonization

    Sophie Amrane / Jean-Christophe Lagier

    Human Microbiome Journal, Vol 16, Iss , Pp 100071- (2020)

    2020  

    Abstract: Patients colonized with antibiotic resistant bacteria are at risk of infections and spontaneous decolonization delays are highly variable between patients. The management of these patients is therefore time-consuming; requires patient isolation, and ... ...

    Abstract Patients colonized with antibiotic resistant bacteria are at risk of infections and spontaneous decolonization delays are highly variable between patients. The management of these patients is therefore time-consuming; requires patient isolation, and cohort policies. Fecal microbiota transplantation (FMT) has been used with the aim of shortening this gut colonization. Here, we proposed a comprehensive literature review on FMT utilization for gut antibiotics resistant bacteria decolonization. After literature research through Pubmed indexed for MEDLINE, we analyzed 23 studies with description of FMT utilization and analyze of gut decolonization. In total, the data involved 197 patients, 153 of whom underwent FMT. Overall, 66.7% (102/153) of the patients were decolonized after FMT. However, we noticed a lot of interpretation bias, such as variation in colonization definition and high disparities in FMT administration modalities. Two disparities were of special interest: repeated FMT seems to increase the effectiveness of decolonization, and gut decolonization with antibiotics before FMT was proposed by some authors, but with too few studies to draw a conclusion. Overall, the use of FMT is a promising perspective for intestinal decolonization, but it requires greater standardization.
    Keywords Fecal microbiota transplantation ; Decolonization ; Antibiotic resistance ; Vancomycin resistant Enterococcus faecium ; And carbapenem resistant Enterobacteriaceae ; Medicine (General) ; R5-920 ; Microbiology ; QR1-502
    Subject code 610
    Language English
    Publishing date 2020-06-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Description of nasopharyngeal bacterial pathogens associated with different SARS-CoV-2 variants.

    Tchoupou Saha, Ornella La Fortune / Dubourg, Grégory / Yacouba, Abdourahamane / Tola, Raphael / Raoult, Didier / Lagier, Jean-Christophe

    Microbial pathogenesis

    2024  Volume 188, Page(s) 106561

    Abstract: The emergence of the coronavirus pandemic facilitated the acquisition of mutations in the SARS-CoV-2 genome, resulting in the appearance of new variants over the past three years. We previously identified several taxa associated with the clinical outcome ...

    Abstract The emergence of the coronavirus pandemic facilitated the acquisition of mutations in the SARS-CoV-2 genome, resulting in the appearance of new variants over the past three years. We previously identified several taxa associated with the clinical outcome of COVID-19 disease in a retrospective study involving 120 patients (infected patients and negative subjects). However, little is known about whether the different variants could influence variations in the composition of the nasopharyngeal microbiota. In this study, we used multiplex pathogen-specific PCR to analyse the presence of nasopharyngeal bacterial pathogens from 400 SARS-CoV-2 positive patients (equally distributed in the four SARS-CoV-2 variants studied: B.1.1.7 (Alpha), B.1 0.617.2 (Delta), B.1.160 (Marseille-4), and B.1.1.529 (omicron)). We then compared them to 400 patients who tested negative for all respiratory viruses tested in this study, including SARS-CoV-2. We first observed an enrichment of Staphylococcus aureus (P ≤ .05) and Corynebacterium propinquum (P ≤ .05) in COVID-19-positive patients, regardless of the variant, compared to negative subjects. We specifically highlighted a significantly higher frequency of S. aureus (P ≤ .0001), C. propinquum (P ≤ .0001), and Klebsiella pneumoniae (P ≤ .0001), in patients infected with the omicron variant, whereas that of Haemophilus influenzae was higher in patients infected with Marseille-4 (P ≤ .001) and Alpha (P ≤ .01) variants. Our results suggest that the nasopharyngeal bacterial pathogens have their own specificity according to the SARS-CoV-2 variant and independently of the season. Additional studies are needed to determine the role of these pathogens in the evolution of the clinical outcome of patients.
    MeSH term(s) Humans ; SARS-CoV-2/genetics ; COVID-19 ; Retrospective Studies ; Staphylococcus aureus
    Language English
    Publishing date 2024-02-01
    Publishing country England
    Document type Journal Article
    ZDB-ID 632772-2
    ISSN 1096-1208 ; 0882-4010
    ISSN (online) 1096-1208
    ISSN 0882-4010
    DOI 10.1016/j.micpath.2024.106561
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Seasonal variation of asymptomatic viral and bacterial nasopharyngeal carriage in rural Senegal.

    Diouf, Fatou Samba / Tidjani Alou, Maryam / Bassene, Hubert / Cortaredona, Sebastien / Diatta, Georges / Raoult, Didier / Sokhna, Cheikh / Lagier, Jean-Christophe

    Journal of infection and public health

    2024  Volume 17, Issue 5, Page(s) 922–928

    Abstract: Background: The surveillance of respiratory pathogens in rural areas of West Africa has, to date, largely been focussed on symptoms. In this prospective study conducted prior to the COVID-19 pandemic, we aimed to assess the asymptomatic prevalence of ... ...

    Abstract Background: The surveillance of respiratory pathogens in rural areas of West Africa has, to date, largely been focussed on symptoms. In this prospective study conducted prior to the COVID-19 pandemic, we aimed to assess the asymptomatic prevalence of respiratory pathogen carriage in a group of individuals living in a rural area of Senegalese.
    Methods: Longitudinal follow up was performed through monthly nasopharyngeal swabbing during the dry season and weekly swabbing during the rainy season. We enrolled 15 individuals from the village of Ndiop. A total of 368 nasopharyngeal swabs were collected over a one-year period. We investigated the prevalence of 18 respiratory viruses and eight respiratory bacteria in different age groups using singleplex and multiplex PCR.
    Results: In total, 19.56% of the samples (72/368) were positive for respiratory viruses and 13.60% of the samples (50/368) were positive for respiratory bacteria. Coronaviruses (19/72, 26.39%), adenoviruses (17/72, 23.61%), rhinoviruses (14/72, 19.44%), Streptococcus pneumoniae (17/50, 34%), and Moraxella catarrhalis (15/50, 30%) were the most frequently detected viruses. Interestingly, the carriage of respiratory pathogens was shown to be more frequent during the rainy season, as pluviometry was shown to be positively associated with the occurrence of respiratory viruses such as influenza (P = .0078, r
    Conclusions: Our results show a non-negligible circulation of respiratory pathogens in a rural area in Senegal (West Africa) with an underestimated proportion of asymptomatic individuals. This study highlights the fact that the circulation of viruses and bacteria in the community has been overlooked.
    MeSH term(s) Humans ; Infant ; Seasons ; Respiratory Tract Infections ; Senegal/epidemiology ; Prospective Studies ; Pandemics ; Nasopharynx ; Bacteria ; Viruses
    Language English
    Publishing date 2024-03-26
    Publishing country England
    Document type Journal Article
    ZDB-ID 2467587-8
    ISSN 1876-035X ; 1876-0341
    ISSN (online) 1876-035X
    ISSN 1876-0341
    DOI 10.1016/j.jiph.2024.03.020
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: New Insights Into the Physiopathology of COVID-19: SARS-CoV-2-Associated Gastrointestinal Illness.

    Devaux, Christian A / Lagier, Jean-Christophe / Raoult, Didier

    Frontiers in medicine

    2021  Volume 8, Page(s) 640073

    Abstract: Although SARS-CoV-2 is considered a lung-tropic virus that infects the respiratory tract through binding to the ACE2 cell-surface molecules present on alveolar lungs epithelial cells, gastrointestinal symptoms have been frequently reported in COVID-19 ... ...

    Abstract Although SARS-CoV-2 is considered a lung-tropic virus that infects the respiratory tract through binding to the ACE2 cell-surface molecules present on alveolar lungs epithelial cells, gastrointestinal symptoms have been frequently reported in COVID-19 patients. What can be considered an apparent paradox is that these symptoms (e.g., diarrhea), sometimes precede the development of respiratory tract illness as if the breathing apparatus was not its first target during viral dissemination. Recently, evidence was reported that the gut is an active site of replication for SARS-CoV-2. This replication mainly occurs in mature enterocytes expressing the ACE2 viral receptor and TMPRSS4 protease. In this review we question how SARS-CoV-2 can cause intestinal disturbances, whether there are pneumocyte-tropic, enterocyte-tropic and/or dual tropic strains of SARS-CoV-2. We examine two major models: first, that of a virus directly causing damage locally (e.g., by inducing apoptosis of infected enterocytes); secondly, that of indirect effect of the virus (e.g., by inducing changes in the composition of the gut microbiota followed by the induction of an inflammatory process), and suggest that both situations probably occur simultaneously in COVID-19 patients. We eventually discuss the consequences of the virus replication in brush border of intestine on long-distance damages affecting other tissues/organs, particularly lungs.
    Language English
    Publishing date 2021-02-18
    Publishing country Switzerland
    Document type Journal Article ; Review
    ZDB-ID 2775999-4
    ISSN 2296-858X
    ISSN 2296-858X
    DOI 10.3389/fmed.2021.640073
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Retraction Note: Repertoire of the gut microbiota from stomach to colon using culturomics and next-generation sequencing.

    Mailhe, Morgane / Ricaboni, Davide / Vitton, Véronique / Gonzalez, Jean-Michel / Bachar, Dipankar / Dubourg, Grégory / Cadoret, Frédéric / Rober, Catherine / Delerce, Jérémy / Levasseur, Anthony / Fournier, Pierre-Edouard / Angelakis, Emmanouil / Lagier, Jean-Christophe / Raoult, Didier

    BMC microbiology

    2024  Volume 24, Issue 1, Page(s) 10

    Language English
    Publishing date 2024-01-03
    Publishing country England
    Document type Retraction of Publication
    ZDB-ID 2041505-9
    ISSN 1471-2180 ; 1471-2180
    ISSN (online) 1471-2180
    ISSN 1471-2180
    DOI 10.1186/s12866-023-03167-3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Cardiovascular Safety of Hydroxychloroquine-Azithromycin in 424 COVID-19 Patients.

    Million, Matthieu / Lagier, Jean-Christophe / Hourdain, Jérôme / Franceschi, Frédéric / Deharo, Jean-Claude / Parola, Philippe / Brouqui, Philippe

    Medicina (Kaunas, Lithuania)

    2023  Volume 59, Issue 5

    Abstract: Background and ... ...

    Abstract Background and Objectives
    MeSH term(s) Adult ; Humans ; Female ; Middle Aged ; Aged ; COVID-19 ; Hydroxychloroquine/adverse effects ; Azithromycin/adverse effects ; SARS-CoV-2 ; Long QT Syndrome/chemically induced ; COVID-19 Drug Treatment ; Electrocardiography/methods
    Chemical Substances Hydroxychloroquine (4QWG6N8QKH) ; Azithromycin (83905-01-5)
    Language English
    Publishing date 2023-04-29
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2188113-3
    ISSN 1648-9144 ; 1010-660X
    ISSN (online) 1648-9144
    ISSN 1010-660X
    DOI 10.3390/medicina59050863
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Correction to: Non contiguous-finished genome sequence and description of Bacillus timonensis sp. nov.

    Kokcha, Sahare / Mishra, Ajay Kumar / Lagier, Jean-Christophe / Million, Matthieu / Leroy, Quentin / Raoult, Didier / Fournier, Pierre-Edouard

    Environmental microbiome

    2023  Volume 18, Issue 1, Page(s) 51

    Language English
    Publishing date 2023-06-07
    Publishing country England
    Document type Published Erratum
    ISSN 2524-6372
    ISSN (online) 2524-6372
    DOI 10.1186/s40793-022-00448-8
    Database MEDical Literature Analysis and Retrieval System OnLINE

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