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  1. Article ; Online: HIV-1 therapeutic vaccines in clinical development to intensify or replace antiretroviral therapy: the promising results of the Tat vaccine.

    Cafaro, Aurelio / Ensoli, Barbara

    Expert review of vaccines

    2022  Volume 21, Issue 9, Page(s) 1243–1253

    Abstract: Introduction: Upon the introduction of the combination antiretroviral therapy (cART), HIV infection has become a chronic disease. However, cART is unable to eradicate the virus and fails to restore the CD4 counts in about 30% of the treated individuals. ...

    Abstract Introduction: Upon the introduction of the combination antiretroviral therapy (cART), HIV infection has become a chronic disease. However, cART is unable to eradicate the virus and fails to restore the CD4 counts in about 30% of the treated individuals. Furthermore, treatment is life-long, and it does not protect from morbidities typically observed in the elderly. Therapeutic vaccines represent the most cost-effective intervention to intensify or replace cART.
    Areas covered: Here, we briefly discuss the obstacles to the development and evaluation of the efficacy of therapeutic vaccines and review recent approaches evaluated in clinical trials.
    Expert opinion: Although vaccines were generally safe and immunogenic, evidence of efficacy was negligible or marginal in most trials. A notable exception is the therapeutic Tat vaccine approach showing promising results of cART intensification, with CD4 T-cell increase and proviral load reduction beyond those afforded by cART alone. Rationale and evidence in support of choosing Tat as the vaccine target are thoroughly discussed.
    MeSH term(s) AIDS Vaccines ; Aged ; HIV Infections/drug therapy ; HIV Infections/prevention & control ; HIV-1 ; Humans ; Viral Load
    Chemical Substances AIDS Vaccines
    Language English
    Publishing date 2022-06-17
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2181284-6
    ISSN 1744-8395 ; 1476-0584
    ISSN (online) 1744-8395
    ISSN 1476-0584
    DOI 10.1080/14760584.2022.2089119
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Role of HIV-1 Tat Protein Interactions with Host Receptors in HIV Infection and Pathogenesis.

    Cafaro, Aurelio / Schietroma, Ivan / Sernicola, Leonardo / Belli, Roberto / Campagna, Massimo / Mancini, Flavia / Farcomeni, Stefania / Pavone-Cossut, Maria Rosaria / Borsetti, Alessandra / Monini, Paolo / Ensoli, Barbara

    International journal of molecular sciences

    2024  Volume 25, Issue 3

    Abstract: Each time the virus starts a new round of expression/replication, even under effective antiretroviral therapy (ART), the transactivator of viral transcription Tat is one of the first HIV-1 protein to be produced, as it is strictly required for HIV ... ...

    Abstract Each time the virus starts a new round of expression/replication, even under effective antiretroviral therapy (ART), the transactivator of viral transcription Tat is one of the first HIV-1 protein to be produced, as it is strictly required for HIV replication and spreading. At this stage, most of the Tat protein exits infected cells, accumulates in the extracellular matrix and exerts profound effects on both the virus and neighbor cells, mostly of the innate and adaptive immune systems. Through these effects, extracellular Tat contributes to the acquisition of infection, spreading and progression to AIDS in untreated patients, or to non-AIDS co-morbidities in ART-treated individuals, who experience inflammation and immune activation despite virus suppression. Here, we review the role of extracellular Tat in both the virus life cycle and on cells of the innate and adaptive immune system, and we provide epidemiological and experimental evidence of the importance of targeting Tat to block residual HIV expression and replication. Finally, we briefly review vaccine studies showing that a therapeutic Tat vaccine intensifies ART, while its inclusion in a preventative vaccine may blunt escape from neutralizing antibodies and block early events in HIV acquisition.
    MeSH term(s) Humans ; HIV Infections ; HIV-1/metabolism ; tat Gene Products, Human Immunodeficiency Virus/metabolism ; Antibodies, Neutralizing ; Vaccines/therapeutic use
    Chemical Substances tat Gene Products, Human Immunodeficiency Virus ; Antibodies, Neutralizing ; Vaccines
    Language English
    Publishing date 2024-01-30
    Publishing country Switzerland
    Document type Journal Article ; Review
    ZDB-ID 2019364-6
    ISSN 1422-0067 ; 1422-0067 ; 1661-6596
    ISSN (online) 1422-0067
    ISSN 1422-0067 ; 1661-6596
    DOI 10.3390/ijms25031704
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: New insights into pathogenesis point to HIV-1 Tat as a key vaccine target

    Ensoli, Barbara / Moretti, Sonia / Borsetti, Alessandra / Maggiorella, Maria Teresa / Buttò, Stefano / Picconi, Orietta / Tripiciano, Antonella / Sgadari, Cecilia / Monini, Paolo / Cafaro, Aurelio

    Archives of virology. 2021 Nov., v. 166, no. 11

    2021  

    Abstract: Despite over 30 years of enormous effort and progress in the field, no preventative and/or therapeutic vaccines against human immunodeficiency virus (HIV) are available. Here, we briefly summarize the vaccine strategies and vaccine candidates that in ... ...

    Abstract Despite over 30 years of enormous effort and progress in the field, no preventative and/or therapeutic vaccines against human immunodeficiency virus (HIV) are available. Here, we briefly summarize the vaccine strategies and vaccine candidates that in recent years advanced to efficacy trials with mostly unsatisfactory results. Next, we discuss a novel and somewhat contrarian approach based on biological and epidemiological evidence, which led us to choose the HIV protein Tat for the development of preventive and therapeutic HIV vaccines. Toward this goal, we review here the role of Tat in the virus life cycle as well as experimental and epidemiological evidence supporting its key role in the natural history of HIV infection and comorbidities. We then discuss the preclinical and clinical development of a Tat therapeutic vaccine, which, by improving the functionality and homeostasis of the immune system and by reducing the viral reservoir in virologically suppressed vaccinees, helps to establish key determinants for intensification of combination antiretroviral therapy (cART) and a functional cure. Future developments and potential applications of the Tat therapeutic vaccine are also discussed, as well as the rationale for its use in preventative strategies. We hope this contribution will lead to a reconsideration of the current paradigms for the development of HIV/AIDS vaccines, with a focus on targeting of viral proteins with key roles in HIV pathogenesis.
    Keywords HIV infections ; antiretroviral agents ; homeostasis ; immune system ; natural history ; pathogenesis ; therapeutics ; vaccines ; virology ; viruses
    Language English
    Dates of publication 2021-11
    Size p. 2955-2974.
    Publishing place Springer Vienna
    Document type Article
    Note Review
    ZDB-ID 7491-3
    ISSN 1432-8798 ; 0304-8608
    ISSN (online) 1432-8798
    ISSN 0304-8608
    DOI 10.1007/s00705-021-05158-z
    Database NAL-Catalogue (AGRICOLA)

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  4. Article: The Tat Protein of HIV-1 Prevents the Loss of HSV-Specific Memory Adaptive Responses and Favors the Control of Viral Reactivation.

    Nicoli, Francesco / Gallerani, Eleonora / Sicurella, Mariaconcetta / Pacifico, Salvatore / Cafaro, Aurelio / Ensoli, Barbara / Marconi, Peggy / Caputo, Antonella / Gavioli, Riccardo

    Vaccines

    2020  Volume 8, Issue 2

    Abstract: The development of therapeutic strategies to control the reactivation of the Herpes Simplex Virus (HSV) is an unaddressed priority. In this study, we evaluated whether Tat, a HIV-1 protein displaying adjuvant functions, could improve previously ... ...

    Abstract The development of therapeutic strategies to control the reactivation of the Herpes Simplex Virus (HSV) is an unaddressed priority. In this study, we evaluated whether Tat, a HIV-1 protein displaying adjuvant functions, could improve previously established HSV-specific memory responses and prevent viral reactivation. To this aim, mice were infected with non-lethal doses of HSV-1 and, 44 days later, injected or not with Tat. Mice were then monitored to check their health status and measure memory HSV-specific cellular and humoral responses. The appearance of symptoms associated with HSV-reactivation was observed at significantly higher frequencies in the control group than in the Tat-treated mice. In addition, the control animals experienced a time-dependent decrease in HSV-specific Immunoglobulin G (IgG), while the Tat-treated mice maintained antibody titers over time. IgG levels were directly correlated with the number of HSV-specific CD8
    Language English
    Publishing date 2020-06-04
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2703319-3
    ISSN 2076-393X
    ISSN 2076-393X
    DOI 10.3390/vaccines8020274
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: HIV therapeutic vaccines aimed at intensifying combination antiretroviral therapy.

    Moretti, Sonia / Cafaro, Aurelio / Tripiciano, Antonella / Picconi, Orietta / Buttò, Stefano / Ensoli, Fabrizio / Sgadari, Cecilia / Monini, Paolo / Ensoli, Barbara

    Expert review of vaccines

    2020  Volume 19, Issue 1, Page(s) 71–84

    Abstract: ... ...

    Abstract Introduction
    MeSH term(s) AIDS Vaccines/administration & dosage ; AIDS Vaccines/immunology ; Animals ; Anti-HIV Agents/administration & dosage ; Anti-HIV Agents/pharmacology ; CD4-Positive T-Lymphocytes/immunology ; Drug Therapy, Combination ; HIV Infections/immunology ; HIV Infections/prevention & control ; HIV Infections/virology ; Humans ; Virus Replication/drug effects
    Chemical Substances AIDS Vaccines ; Anti-HIV Agents
    Language English
    Publishing date 2020-01-19
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 2181284-6
    ISSN 1744-8395 ; 1476-0584
    ISSN (online) 1744-8395
    ISSN 1476-0584
    DOI 10.1080/14760584.2020.1712199
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: Anti-Tat Immunity in HIV-1 Infection: Effects of Naturally Occurring and Vaccine-Induced Antibodies Against Tat on the Course of the Disease.

    Cafaro, Aurelio / Tripiciano, Antonella / Picconi, Orietta / Sgadari, Cecilia / Moretti, Sonia / Buttò, Stefano / Monini, Paolo / Ensoli, Barbara

    Vaccines

    2019  Volume 7, Issue 3

    Abstract: HIV-1 Tat is an essential protein in the virus life cycle, which is required for virus gene expression and replication. Most Tat that is produced during infection is released extracellularly and it plays a key role in HIV pathogenesis, including residual ...

    Abstract HIV-1 Tat is an essential protein in the virus life cycle, which is required for virus gene expression and replication. Most Tat that is produced during infection is released extracellularly and it plays a key role in HIV pathogenesis, including residual disease upon combination antiretroviral therapy (cART). Here, we review epidemiological and experimental evidence showing that antibodies against HIV-1 Tat, infrequently occurring in natural infection, play a protective role against disease progression, and that vaccine targeting Tat can intensify cART. In fact, Tat vaccination of subjects on suppressive cART in Italy and South Africa promoted immune restoration, including CD4+ T-cell increase in low immunological responders, and a reduction of proviral DNA even after six years of cART, when both CD4+ T-cell gain and DNA decay have reached a plateau. Of note, DNA decay was predicted by the neutralization of Tat-mediated entry of Env into dendritic cells by anti-Tat antibodies, which were cross-clade binding and neutralizing. Anti-Tat cellular immunity also contributed to the DNA decay. Based on these data, we propose the Tat therapeutic vaccine as a pathogenesis-driven intervention that effectively intensifies cART and it may lead to a functional cure, providing new perspectives and opportunities also for prevention and virus eradication strategies.
    Language English
    Publishing date 2019-08-26
    Publishing country Switzerland
    Document type Journal Article ; Review
    ZDB-ID 2703319-3
    ISSN 2076-393X
    ISSN 2076-393X
    DOI 10.3390/vaccines7030099
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: New insights into pathogenesis point to HIV-1 Tat as a key vaccine target.

    Ensoli, Barbara / Moretti, Sonia / Borsetti, Alessandra / Maggiorella, Maria Teresa / Buttò, Stefano / Picconi, Orietta / Tripiciano, Antonella / Sgadari, Cecilia / Monini, Paolo / Cafaro, Aurelio

    Archives of virology

    2021  Volume 166, Issue 11, Page(s) 2955–2974

    Abstract: Despite over 30 years of enormous effort and progress in the field, no preventative and/or therapeutic vaccines against human immunodeficiency virus (HIV) are available. Here, we briefly summarize the vaccine strategies and vaccine candidates that in ... ...

    Abstract Despite over 30 years of enormous effort and progress in the field, no preventative and/or therapeutic vaccines against human immunodeficiency virus (HIV) are available. Here, we briefly summarize the vaccine strategies and vaccine candidates that in recent years advanced to efficacy trials with mostly unsatisfactory results. Next, we discuss a novel and somewhat contrarian approach based on biological and epidemiological evidence, which led us to choose the HIV protein Tat for the development of preventive and therapeutic HIV vaccines. Toward this goal, we review here the role of Tat in the virus life cycle as well as experimental and epidemiological evidence supporting its key role in the natural history of HIV infection and comorbidities. We then discuss the preclinical and clinical development of a Tat therapeutic vaccine, which, by improving the functionality and homeostasis of the immune system and by reducing the viral reservoir in virologically suppressed vaccinees, helps to establish key determinants for intensification of combination antiretroviral therapy (cART) and a functional cure. Future developments and potential applications of the Tat therapeutic vaccine are also discussed, as well as the rationale for its use in preventative strategies. We hope this contribution will lead to a reconsideration of the current paradigms for the development of HIV/AIDS vaccines, with a focus on targeting of viral proteins with key roles in HIV pathogenesis.
    MeSH term(s) AIDS Vaccines/immunology ; AIDS Vaccines/pharmacology ; Clinical Trials, Phase I as Topic ; Clinical Trials, Phase II as Topic ; Comorbidity ; HIV Infections/epidemiology ; HIV Infections/transmission ; HIV Infections/virology ; HIV-1/pathogenicity ; HIV-1/physiology ; Humans ; tat Gene Products, Human Immunodeficiency Virus/immunology ; tat Gene Products, Human Immunodeficiency Virus/physiology
    Chemical Substances AIDS Vaccines ; tat Gene Products, Human Immunodeficiency Virus
    Language English
    Publishing date 2021-08-14
    Publishing country Austria
    Document type Journal Article ; Review
    ZDB-ID 7491-3
    ISSN 1432-8798 ; 0304-8608
    ISSN (online) 1432-8798
    ISSN 0304-8608
    DOI 10.1007/s00705-021-05158-z
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article: Challenges in HIV Vaccine Research for Treatment and Prevention.

    Ensoli, Barbara / Cafaro, Aurelio / Monini, Paolo / Marcotullio, Simone / Ensoli, Fabrizio

    Frontiers in immunology

    2014  Volume 5, Page(s) 417

    Abstract: Many attempts have been made or are ongoing for HIV prevention and HIV cure. Many successes are in the list, particularly for HIV drugs, recently proposed also for prevention. However, no eradication of infection has been achieved so far with any drug. ... ...

    Abstract Many attempts have been made or are ongoing for HIV prevention and HIV cure. Many successes are in the list, particularly for HIV drugs, recently proposed also for prevention. However, no eradication of infection has been achieved so far with any drug. Further, a residual immune dysregulation associated to chronic immune activation and incomplete restoration of B and T cell subsets, together with HIV DNA persistence in reservoirs, are still unmet needs of the highly active antiretroviral therapy, causing novel "non-AIDS related" diseases that account for a higher risk of death even in virologically suppressed patients. These "ART unmet needs" represent a problem, which is expected to increase by ART roll out. Further, in countries such as South Africa, where six millions of individuals are infected, ART appears unable to contain the epidemics. Regretfully, all the attempts at developing a preventative vaccine have been largely disappointing. However, recent therapeutic immunization strategies have opened new avenues for HIV treatment, which might be exploitable also for preventative vaccine approaches. For example, immunization strategies aimed at targeting key viral products responsible of virus transmission, activation, and maintenance of virus reservoirs may intensify drug efficacy and lead to a functional cure providing new perspectives also for prevention and future virus eradication strategies. However, this approach imposes new challenges to the scientific community, vaccine developers, and regulatory bodies, such as the identification of novel immunological and virological biomarkers to assess efficacy end-points, taking advantage from the natural history of infection and exploiting lessons from former trials. This review will focus first on recent advancement of therapeutic strategies, then on the progresses made in preventative approaches, discussing concepts, and problems for the way ahead for the development of vaccines for HIV treatment and prevention.
    Language English
    Publishing date 2014-09-08
    Publishing country Switzerland
    Document type Journal Article ; Review
    ZDB-ID 2606827-8
    ISSN 1664-3224
    ISSN 1664-3224
    DOI 10.3389/fimmu.2014.00417
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: HIV-1 Tat Protein Enters Dysfunctional Endothelial Cells via Integrins and Renders Them Permissive to Virus Replication.

    Cafaro, Aurelio / Barillari, Giovanni / Moretti, Sonia / Palladino, Clelia / Tripiciano, Antonella / Falchi, Mario / Picconi, Orietta / Pavone Cossut, Maria Rosaria / Campagna, Massimo / Arancio, Angela / Sgadari, Cecilia / Andreini, Claudia / Banci, Lucia / Monini, Paolo / Ensoli, Barbara

    International journal of molecular sciences

    2020  Volume 22, Issue 1

    Abstract: Previous work has shown that the Tat protein of Human Immunodeficiency Virus (HIV)-1 is released by acutely infected cells in a biologically active form and enters dendritic cells upon the binding of its arginine-glycine-aspartic acid (RGD) domain to the ...

    Abstract Previous work has shown that the Tat protein of Human Immunodeficiency Virus (HIV)-1 is released by acutely infected cells in a biologically active form and enters dendritic cells upon the binding of its arginine-glycine-aspartic acid (RGD) domain to the α5β1, αvβ3, and αvβ5 integrins. The up-regulation/activation of these integrins occurs in endothelial cells exposed to inflammatory cytokines that are increased in HIV-infected individuals, leading to endothelial cell dysfunction. Here, we show that inflammatory cytokine-activated endothelial cells selectively bind and rapidly take up nano-micromolar concentrations of Tat, as determined by flow cytometry. Protein oxidation and low temperatures reduce Tat entry, suggesting a conformation- and energy-dependent process. Consistently, Tat entry is competed out by RGD-Tat peptides or integrin natural ligands, and it is blocked by anti-α5β1, -αvβ3, and -αvβ5 antibodies. Moreover, modelling-docking calculations identify a low-energy Tat-αvβ3 integrin complex in which Tat makes contacts with both the αv and β3 chains. It is noteworthy that internalized Tat induces HIV replication in inflammatory cytokine-treated, but not untreated, endothelial cells. Thus, endothelial cell dysfunction driven by inflammatory cytokines renders the vascular system a target of Tat, which makes endothelial cells permissive to HIV replication, adding a further layer of complexity to functionally cure and/or eradicate HIV infection.
    MeSH term(s) Alkynes/pharmacology ; Benzoxazines/pharmacology ; Biomarkers ; Cell Adhesion ; Cell-Penetrating Peptides/metabolism ; Cyclopropanes/pharmacology ; Cytokines/metabolism ; Endothelial Cells/metabolism ; Endothelial Cells/virology ; Fibronectins/metabolism ; HIV Infections/metabolism ; HIV Infections/virology ; HIV-1/drug effects ; HIV-1/physiology ; Host-Pathogen Interactions ; Humans ; Inflammation Mediators/metabolism ; Integrins/chemistry ; Integrins/metabolism ; Models, Molecular ; Oxidation-Reduction ; Protein Binding ; Protein Conformation ; Protein Interaction Domains and Motifs ; Structure-Activity Relationship ; Temperature ; Virus Replication ; Vitronectin/metabolism ; tat Gene Products, Human Immunodeficiency Virus/chemistry ; tat Gene Products, Human Immunodeficiency Virus/metabolism
    Chemical Substances Alkynes ; Benzoxazines ; Biomarkers ; Cell-Penetrating Peptides ; Cyclopropanes ; Cytokines ; Fibronectins ; Inflammation Mediators ; Integrins ; Vitronectin ; tat Gene Products, Human Immunodeficiency Virus ; efavirenz (JE6H2O27P8)
    Language English
    Publishing date 2020-12-30
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2019364-6
    ISSN 1422-0067 ; 1422-0067 ; 1661-6596
    ISSN (online) 1422-0067
    ISSN 1422-0067 ; 1661-6596
    DOI 10.3390/ijms22010317
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: The HIV-1 Tat protein affects human CD4+ T-cell programing and activation, and favors the differentiation of naïve CD4+ T cells.

    Nicoli, Francesco / Gallerani, Eleonora / Sforza, Fabio / Finessi, Valentina / Chachage, Mkunde / Geldmacher, Christof / Cafaro, Aurelio / Ensoli, Barbara / Caputo, Antonella / Gavioli, Riccardo

    AIDS (London, England)

    2017  Volume 32, Issue 5, Page(s) 575–581

    Abstract: Objective: HIV infection is characterized by several immune dysfunctions, such as chronic activation of the immune system, premature aging and loss of CD4 T cells, in particular within the naïve compartment. The Tat protein of HIV is released ... ...

    Abstract Objective: HIV infection is characterized by several immune dysfunctions, such as chronic activation of the immune system, premature aging and loss of CD4 T cells, in particular within the naïve compartment. The Tat protein of HIV is released extracellularly and enters neighboring cells affecting their functionality, for instance impacting on CD8 T-cell programs and activity. As the presence and/or induction of anti-Tat immune responses is associated with reduced T-cell dysfunction and CD4 T-cell loss, we investigated whether Tat impacts human resting or activated CD4 T cells.
    Methods: Purified CD4 T cells were activated by T cell receptor engagement in the presence or absence of Tat. Cytokine production, surface phenotype and expression of transcription factors important for T-cell programing were measured. Purified naïve CD4 T cells were cultured in nonpolarizing conditions in the presence or absence of Tat and their proliferation and differentiation was evaluated.
    Results: Tat favors the secretion of IL2, IFNγ and TNFα in CD4 T cells, as well as the upregulation of T-bet and Eomes expression. Naïve CD4 T cells cultured in the presence of Tat showed enhanced expansion and differentiation toward memory phenotype, showing in particular recruitment into the effector memory T-cell pool.
    Conclusion: Tat affects the programing and functionality of CD4 T lymphocytes favoring the differentiation of naïve CD4 T cells.
    MeSH term(s) Antigens, CD/analysis ; CD4-Positive T-Lymphocytes/drug effects ; CD4-Positive T-Lymphocytes/immunology ; Cell Differentiation/drug effects ; Cytokines/metabolism ; HIV Infections/pathology ; Host-Pathogen Interactions ; Humans ; Lymphocyte Activation/drug effects ; tat Gene Products, Human Immunodeficiency Virus/metabolism
    Chemical Substances Antigens, CD ; Cytokines ; tat Gene Products, Human Immunodeficiency Virus
    Language English
    Publishing date 2017-12-27
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 639076-6
    ISSN 1473-5571 ; 0269-9370 ; 1350-2840
    ISSN (online) 1473-5571
    ISSN 0269-9370 ; 1350-2840
    DOI 10.1097/QAD.0000000000001734
    Database MEDical Literature Analysis and Retrieval System OnLINE

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