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  1. Article: Intra-erythrocytic vacuoles in asplenic patients: elusive genesis and original clearance of unique organelles.

    Dumas, Lucie / Roussel, Camille / Buffet, Pierre

    Frontiers in physiology

    2023  Volume 14, Page(s) 1324463

    Abstract: The spleen plays a dual role of immune response and the filtration of red blood cells (RBC), the latter function being performed within the unique microcirculatory architecture of the red pulp. The red pulp filters and eliminates senescent and ... ...

    Abstract The spleen plays a dual role of immune response and the filtration of red blood cells (RBC), the latter function being performed within the unique microcirculatory architecture of the red pulp. The red pulp filters and eliminates senescent and pathological RBC and can expell intra-erythrocytic rigid bodies through the so-called pitting mechanism. The loss of splenic function increases the risk of infections, thromboembolism, and hematological malignancies. However, current diagnostic tests such as quantification of Howell-Jolly Bodies and splenic scintigraphy lack sensitivity or are logistically demanding. Although not widely available in medical practice, the quantification of RBC containing vacuoles, i.e., pocked RBC, is a highly sensitive and specific marker for hyposplenism. The peripheral blood of hypo/asplenic individuals contains up to 80% RBC with vacuoles, whereas these pocked RBC account for less than 4% of RBC in healthy subjects. Despite their value as a spleen function test, intraerythrocytic vacuoles have received relatively limited attention so far, and little is known about their origin, content, and clearance. We provide an overview of the current knowledge regarding possible origins and mechanisms of elimination, as well as the potential function of these unique and original organelles observed in otherwise "empty" mature RBC. We highlight the need for further research on pocked RBC, particularly regarding their potential function and specific markers for easy counting and sorting, which are prerequisites for functional studies and wider application in medical practice.
    Language English
    Publishing date 2023-12-18
    Publishing country Switzerland
    Document type Journal Article ; Review
    ZDB-ID 2564217-0
    ISSN 1664-042X
    ISSN 1664-042X
    DOI 10.3389/fphys.2023.1324463
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Un migrant de 19 ans consulte pour une urétrite et une éruption vésiculeuse.

    Hochedez, Patrick / Consigny, Paul-Henri / Durand, Agnès / Buffet, Pierre

    Medecine tropicale et sante internationale

    2023  Volume 3, Issue 3

    Abstract: We report the case of a 19-year-old Malian patient, who presented with urethritis and a vesicular rash during the summer of 2022, following a probable heterosexual intercourse. The epidemic context among the male homosexual population and the clinical ... ...

    Title translation A 19-year-old male migrant with urethritis and vesicular rash.
    Abstract We report the case of a 19-year-old Malian patient, who presented with urethritis and a vesicular rash during the summer of 2022, following a probable heterosexual intercourse. The epidemic context among the male homosexual population and the clinical picture without genital lesions or lymphadenopathy allowed us to discuss both chickenpox and mpox, the latter being finally confirmed by the detection of Monkeypox virus DNA from vesicular fluid.
    MeSH term(s) Humans ; Male ; Young Adult ; Exanthema/etiology ; Homosexuality, Male ; Transients and Migrants ; Urethritis/diagnosis ; Urethritis/etiology ; Skin Diseases, Vesiculobullous/etiology ; Mpox (monkeypox)/complications ; Mpox (monkeypox)/diagnosis ; Mpox (monkeypox)/virology ; Monkeypox virus/isolation & purification
    Language French
    Publishing date 2023-09-04
    Publishing country France
    Document type Case Reports ; English Abstract ; Journal Article
    ISSN 2778-2034
    ISSN (online) 2778-2034
    DOI 10.48327/mtsi.v3i3.2023.376
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Marginal-Zone Lymphomas.

    Henry, Benoît / Buffet, Pierre / Bates, Imelda

    The New England journal of medicine

    2022  Volume 386, Issue 20, Page(s) 1962

    MeSH term(s) Humans ; Lymphoma, B-Cell, Marginal Zone/diagnosis ; Lymphoma, B-Cell, Marginal Zone/pathology
    Language English
    Publishing date 2022-06-07
    Publishing country United States
    Document type Letter ; Comment
    ZDB-ID 207154-x
    ISSN 1533-4406 ; 0028-4793
    ISSN (online) 1533-4406
    ISSN 0028-4793
    DOI 10.1056/NEJMc2203319
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Disseminated mucocutaneous leishmaniasis in a traveller with idiopathic CD4 lymphocytopenia.

    Thizy, Guillaume / Caumes, Eric / Molher, Joffrey / Ariey, Frederic / Lortholary, Olivier / Buffet, Pierre / Melenotte, Cléa

    Journal of travel medicine

    2023  Volume 30, Issue 8

    MeSH term(s) Humans ; Leishmaniasis, Mucocutaneous/diagnosis ; Leishmaniasis, Mucocutaneous/drug therapy ; Immunologic Deficiency Syndromes ; Thymus Gland ; Lymphopenia
    Language English
    Publishing date 2023-05-08
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1212504-0
    ISSN 1708-8305 ; 1195-1982
    ISSN (online) 1708-8305
    ISSN 1195-1982
    DOI 10.1093/jtm/taad063
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: A combined computational and experimental investigation of the filtration function of splenic macrophages in sickle cell disease.

    Li, Guansheng / Qiang, Yuhao / Li, He / Li, Xuejin / Buffet, Pierre A / Dao, Ming / Karniadakis, George Em

    PLoS computational biology

    2023  Volume 19, Issue 12, Page(s) e1011223

    Abstract: Being the largest lymphatic organ in the body, the spleen also constantly controls the quality of red blood cells (RBCs) in circulation through its two major filtration components, namely interendothelial slits (IES) and red pulp macrophages. In contrast ...

    Abstract Being the largest lymphatic organ in the body, the spleen also constantly controls the quality of red blood cells (RBCs) in circulation through its two major filtration components, namely interendothelial slits (IES) and red pulp macrophages. In contrast to the extensive studies in understanding the filtration function of IES, fewer works investigate how the splenic macrophages retain the aged and diseased RBCs, i.e., RBCs in sickle cell disease (SCD). Herein, we perform a computational study informed by companion experiments to quantify the dynamics of RBCs captured and retained by the macrophages. We first calibrate the parameters in the computational model based on microfluidic experimental measurements for sickle RBCs under normoxia and hypoxia, as those parameters are not available in the literature. Next, we quantify the impact of key factors expected to dictate the RBC retention by the macrophages in the spleen, namely, blood flow conditions, RBC aggregation, hematocrit, RBC morphology, and oxygen levels. Our simulation results show that hypoxic conditions could enhance the adhesion between the sickle RBCs and macrophages. This, in turn, increases the retention of RBCs by as much as four-fold, which could be a possible cause of RBC congestion in the spleen of patients with SCD. Our study on the impact of RBC aggregation illustrates a 'clustering effect', where multiple RBCs in one aggregate can make contact and adhere to the macrophages, leading to a higher retention rate than that resulting from RBC-macrophage pair interactions. Our simulations of sickle RBCs flowing past macrophages for a range of blood flow velocities indicate that the increased blood velocity could quickly attenuate the function of the red pulp macrophages on detaining aged or diseased RBCs, thereby providing a possible rationale for the slow blood flow in the open circulation of the spleen. Furthermore, we quantify the impact of RBC morphology on their tendency to be retained by the macrophages. We find that the sickle and granular-shaped RBCs are more likely to be filtered by macrophages in the spleen. This finding is consistent with the observation of low percentages of these two forms of sickle RBCs in the blood smear of SCD patients. Taken together, our experimental and simulation results aid in our quantitative understanding of the function of splenic macrophages in retaining the diseased RBCs and provide an opportunity to combine such knowledge with the current knowledge of the interaction between IES and traversing RBCs to apprehend the complete filtration function of the spleen in SCD.
    MeSH term(s) Humans ; Aged ; Anemia, Sickle Cell ; Erythrocytes ; Spleen/physiology ; Hematologic Diseases ; Macrophages
    Language English
    Publishing date 2023-12-13
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2193340-6
    ISSN 1553-7358 ; 1553-734X
    ISSN (online) 1553-7358
    ISSN 1553-734X
    DOI 10.1371/journal.pcbi.1011223
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: A combined computational and experimental investigation of the filtration function of splenic macrophages in sickle cell disease.

    Li, Guansheng / Qiang, Yuhao / Li, He / Li, Xuejin / Buffet, Pierre A / Dao, Ming / Karniadakis, George Em

    bioRxiv : the preprint server for biology

    2023  

    Abstract: Being the largest lymphatic organ in the body, the spleen also constantly controls the quality of red blood cells (RBCs) in circulation through its two major filtration components, namely interendothelial slits (IES) and red pulp macrophages. In contrast ...

    Abstract Being the largest lymphatic organ in the body, the spleen also constantly controls the quality of red blood cells (RBCs) in circulation through its two major filtration components, namely interendothelial slits (IES) and red pulp macrophages. In contrast to the extensive studies in understanding the filtration function of IES, there are relatively fewer works on investigating how the splenic macrophages retain the aged and diseased RBCs, i.e., RBCs in sickle cell disease (SCD). Herein, we perform a computational study informed by companion experiments to quantify the dynamics of RBCs captured and retained by the macrophages. We first calibrate the parameters in the computational model based on microfluidic experimental measurements for sickle RBCs under normoxia and hypoxia, as those parameters are not available in the literature. Next, we quantify the impact of a set of key factors that are expected to dictate the RBC retention by the macrophages in the spleen, namely, blood flow conditions, RBC aggregation, hematocrit, RBC morphology, and oxygen levels. Our simulation results show that hypoxic conditions could enhance the adhesion between the sickle RBCs and macrophages. This, in turn, increases the retention of RBCs by as much as five-fold, which could be a possible cause of RBC congestion in the spleen of patients with SCD. Our study on the impact of RBC aggregation illustrates a 'clustering effect', where multiple RBCs in one aggregate can make contact and adhere to the macrophages, leading to a higher retention rate than that resulting from RBC-macrophage pair interactions. Our simulations of sickle RBCs flowing past macrophages for a range of blood flow velocities indicate that the increased blood velocity could quickly attenuate the function of the red pulp macrophages on detaining aged or diseased RBCs, thereby providing a possible rationale for the slow blood flow in the open circulation of the spleen. Furthermore, we quantify the impact of RBC morphology on their tendency to be retained by the macrophages. We find that the sickle and granular-shaped RBCs are more likely to be filtered by macrophages in the spleen. This finding is consistent with the observation of low percentages of these two forms of sickle RBCs in the blood smear of SCD patients. Taken together, our experimental and simulation results aid in our quantitative understanding of the function of splenic macrophages in retaining the diseased RBCs and provide an opportunity to combine such knowledge with the current knowledge of the interaction between IES and traversing RBCs to apprehend the complete filtration function of the spleen in SCD.
    Language English
    Publishing date 2023-06-03
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2023.05.31.543007
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Health problems and exposure to infectious risks in returning humanitarian aid workers.

    Benabdelmoumen, Ghania / Van der Pluijm, Rob W / Taieb, Fabien / Jidar, Kaoutar / Kuhmel, Lucie / Lucet, Cora / Buffet, Pierre / Hochedez, Patrick / Itani, Oula / Consigny, Paul-Henri

    Journal of travel medicine

    2024  

    Abstract: Background: Humanitarian aid workers are exposed to deployment-related health threats. Identifying subgroups at higher risk of infection in this diverse population could help optimize prevention.: Methods: We carried out a retrospective study based ... ...

    Abstract Background: Humanitarian aid workers are exposed to deployment-related health threats. Identifying subgroups at higher risk of infection in this diverse population could help optimize prevention.
    Methods: We carried out a retrospective study based on anonymized data of humanitarian aid workers that visited our clinic for a post-deployment visit between January 1st, 2018, and December 31st, 2021. We conducted a descriptive analysis of basic demographic data, self-reported risk exposure and health problems encountered during deployment extracted from a standard questionnaire.
    Results: The questionnaire was administered to 1238 aid workers during 1529 post-deployment medical consultations. The median age was 37.2 years (IQR 31.7-44.3) and 718/1529 (47.0%) were female aid workers. The median duration of deployment was 6 months (IQR 3-12 months). Most deployments (1321/1529 (86.4%)) were for a medical organization and in Sub-Saharan Africa (73.2%).The most common risk exposures were contact with freshwater in schistosomiasis endemic regions (187/1308 (14.3%)); unprotected sexual contact with a person other than a regular partner (138/1529 (9.0%)); suspected rabies exposure (56/1529 (3.7%)); and accidental exposure to blood (44/1529 (2.9%)).Gastrointestinal problems (487/1529 (31.9%)), malaria (237/1529 (15.5%)) and respiratory tract infections (94/1529 (6,2%)) were the most encountered health problems. Fifteen volunteers (1%) were hospitalized during deployment and 19 (1.2%) repatriated due to health problems. Adherence to malaria chemoprophylaxis was poor, only taken according to prescription in 355 out of 1225 (29.0%) of aid workers for whom prophylaxis was indicated.
    Conclusion: Humanitarian aid workers deployed abroad encounter significant rates of health problems and report a high level of risk exposure during their deployment, with the risks being greatest among younger people, those deployed to rural areas, and those working for non-medical organizations. These findings help guide future pre-deployment consultations, to increase awareness and reduce risk behaviour during deployment, as well as focus on adherence to medical advice such as malaria chemoprophylaxis.
    Language English
    Publishing date 2024-03-29
    Publishing country England
    Document type Journal Article
    ZDB-ID 1212504-0
    ISSN 1708-8305 ; 1195-1982
    ISSN (online) 1708-8305
    ISSN 1195-1982
    DOI 10.1093/jtm/taae050
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Surge in Imported Cutaneous Leishmaniasis Cases from Mexico in 2023: A Case Series.

    Equihua Martinez, Gabriela / Del Moreno Castillo, Maria Cristina / Lindner, Andreas K / Gargala, Gilles / Cessot, Gilles / van de Werve, Charlotte / Caumes, Eric / Harms, Gundel / Aurbach, Ute / Kampmann, Beate / Buffet, Pierre / Melenotte, Cléa

    Journal of travel medicine

    2024  

    Abstract: In Europe, American cutaneous leishmaniasis caused by Leishmania mexicana is a rare imported disease. A series of six cases in 2023 is a noteworthy escalation at our institutions compared to the past two decades. This surge is likely linked to an ... ...

    Abstract In Europe, American cutaneous leishmaniasis caused by Leishmania mexicana is a rare imported disease. A series of six cases in 2023 is a noteworthy escalation at our institutions compared to the past two decades. This surge is likely linked to an increase of cases and environmental changes in South-Eastern Mexico.
    Language English
    Publishing date 2024-04-05
    Publishing country England
    Document type Journal Article
    ZDB-ID 1212504-0
    ISSN 1708-8305 ; 1195-1982
    ISSN (online) 1708-8305
    ISSN 1195-1982
    DOI 10.1093/jtm/taae051
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  9. Article: Methods to Investigate the Deformability of RBC During Malaria.

    Depond, Mallorie / Henry, Benoit / Buffet, Pierre / Ndour, Papa Alioune

    Frontiers in physiology

    2020  Volume 10, Page(s) 1613

    Abstract: Despite a 30% decline in mortality since 2000, malaria still affected 219 million subjects and caused 435,000 deaths in 2017. Red blood cells (RBC) ... ...

    Abstract Despite a 30% decline in mortality since 2000, malaria still affected 219 million subjects and caused 435,000 deaths in 2017. Red blood cells (RBC) host
    Language English
    Publishing date 2020-01-21
    Publishing country Switzerland
    Document type Journal Article ; Review
    ZDB-ID 2564217-0
    ISSN 1664-042X
    ISSN 1664-042X
    DOI 10.3389/fphys.2019.01613
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: [No title information]

    Buffet, Pierre / Danis, Martin

    Bulletin de l'Academie nationale de medecine

    2016  Volume 200, Issue 3, Page(s) 493–495

    Title translation Élimination du paludisme, un objectif envisageable? Coordonner les actions.
    MeSH term(s) Africa ; Child ; Disease Eradication/organization & administration ; Humans ; Malaria/prevention & control ; Organizational Objectives
    Language French
    Publishing date 2016
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 213227-8
    ISSN 0001-4079
    ISSN 0001-4079
    Database MEDical Literature Analysis and Retrieval System OnLINE

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