75 research outputs found

    Opportunistic and Other Infections in HIV-Infected Children in Latin America Compared to a Similar Cohort in the United States

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    Opportunistic and other infections have declined since the introduction of highly active antiretroviral therapy (HAART) in developed countries but few studies have addressed the impact of HAART in HIV-infected children from developing countries. This study examines the prevalence and incidence of opportunistic and other infections in Latin America during the HAART era. Vertically HIV-infected children enrolled in a cohort study between 2002 and 2007 were followed for the occurrence of 29 targeted infections. Cross-sectional and longitudinal analyses were performed to calculate the prevalence of infections before enrollment and the incidence rates of opportunistic and other infections after enrollment. Comparisons were made with data from a U. S. cohort (PACTG 219C). Of the 731 vertically HIV-infected children 568 (78%) had at least one opportunistic or other infection prior to enrollment. The most prevalent infections were bacterial pneumonia, oral candidiasis, varicella, tuberculosis, herpes zoster, and Pneumocystis jiroveci pneumonia. After enrollment, the overall incidence was 23.5 per 100 person-years; the most common infections (per 100 person-years) were bacterial pneumonia (7.8), varicella (3.0), dermatophyte infections (2.9), herpes simplex (2.5), and herpes zoster (1.8). All of these incidence rates were higher than those reported in PACTG 219C. The types and relative distribution of infections among HIV-infected children in Latin America in this study are similar to those seen in the United States but the incidence rates are higher. Further research is necessary to determine the reasons for these higher rates.NICHD [N01-HD-3-3345, HHSN267200800001C, N01-HD-8-0001

    First Colombian Multicentric Newborn Screening for Congenital Toxoplasmosis

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    Congenital toxoplasmosis can result in permanent sequel as blindness or neurological damage in children and it seems to be more severe in South America than in other continents. There is a lack of information about this frequency in Colombia, where no control program is established, although it is a recognized cause of potentially preventable congenital blindness. We propose the first Colombian multicentric study to determine the frequency and impact of congenital toxoplasmosis. More than 15,000 newborns in seven cities were studied. Newborns were tested at birth by doing a cord blood test for toxoplasmosis. Additionally, children from mothers with history of toxoplasmosis acquired during pregnancy were recalled for a follow-up. The program identified fifteen children otherwise undiagnosed; three of these children died as consequence of congenital toxoplasmosis. The frequency of the congenital infection varied significantly between cities, being higher in Armenia and Florencia, intermediate in Bogota, Bucaramanga and Barranquilla and very low in western cities such as Cucuta and Riohacha. For the first time a significant correlation was found between mean rainfall at the city and the incidence of this congenital infection

    Autoantibodies against type I IFNs in patients with life-threatening COVID-19

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    Interindividual clinical variability in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is vast. We report that at least 101 of 987 patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia had neutralizing immunoglobulin G (IgG) autoantibodies (auto-Abs) against interferon-w (IFN-w) (13 patients), against the 13 types of IFN-a (36), or against both (52) at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 of the 101 were men. A B cell autoimmune phenocopy of inborn errors of type I IFN immunity accounts for life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men

    Stabilization effect of intrinsically disordered regions on multidomain proteins: The case of the methyl-cpg protein 2, mecp2

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    18 pags., 8 figs., 6 tabs. -- This article belongs to the Special Issue The Amazing World of IDPs in Human Diseases IIIntrinsic disorder plays an important functional role in proteins. Disordered regions are linked to posttranslational modifications, conformational switching, extra/intracellular trafficking, and allosteric control, among other phenomena. Disorder provides proteins with enhanced plasticity, resulting in a dynamic protein conformational/functional landscape, with well-structured and disordered regions displaying reciprocal, interdependent features. Although lacking well-defined conformation, disordered regions may affect the intrinsic stability and functional properties of ordered regions. MeCP2, methyl-CpG binding protein 2, is a multifunctional transcriptional regulator associated with neuronal development and maturation. MeCP2 multidomain structure makes it a prototype for multidomain, multifunctional, intrinsically disordered proteins (IDP). The methyl-binding domain (MBD) is one of the key domains in MeCP2, responsible for DNA recognition. It has been reported previously that the two disordered domains flanking MBD, the N-terminal domain (NTD) and the intervening domain (ID), increase the intrinsic stability of MBD against thermal denaturation. In order to prove unequivocally this stabilization effect, ruling out any artifactual result from monitoring the unfolding MBD with a local fluorescence probe (the single tryptophan in MBD) or from driving the protein unfolding by temperature, we have studied the MBD stability by differential scanning calorimetry (reporting on the global unfolding process) and chemical denaturation (altering intramolecular interactions by a different mechanism compared to thermal denaturation).This research was funded by the Spanish Ministry of Economy and Competitiveness and European ERDF Funds (MCIU/AEI/FEDER, EU) (BFU2016-78232-P to A.V.C.; BES-2017-080739 to D.O.A.); Miguel Servet Program from Instituto de Salud Carlos III (CPII13/00017 to O.A.); Fondo de Investigaciones Sanitarias from Instituto de Salud Carlos III and European Union (ERDF/ESF, “Investing in your future”) (PI15/00663 and PI18/00349 to O.A.); Diputación General de Aragón (Protein Targets and Bioactive Compounds Group E45_20R to A.V.C. and Digestive Pathology Group B25_20R to O.A.); and the Centro de Investigación Biomédica en Red en Enfermedades Hepáticas y Digestivas (CIBERehd)

    Molecular context-dependent effects induced by rett syndrome-associated mutations in MeCP2

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    19 pags., 8 figs., 4 tabs. -- This article belongs to the Special Issue The Amazing World of IDPs in Human DiseasesMethyl-CpG binding protein 2 (MeCP2) is a transcriptional regulator and a chromatin-binding protein involved in neuronal development and maturation. Loss-of-function mutations in MeCP2 result in Rett syndrome (RTT), a neurodevelopmental disorder that is the main cause of mental retardation in females. MeCP2 is an intrinsically disordered protein (IDP) constituted by six domains. Two domains are the main responsible elements for DNA binding (methyl-CpG binding domain, MBD) and recruitment of gene transcription/silencing machinery (transcription repressor domain, TRD). These two domains concentrate most of the RTT-associated mutations. R106W and R133C are associated with severe and mild RTT phenotype, respectively. We have performed a comprehensive characterization of the structural and functional impact of these substitutions at molecular level. Because we have previously shown that the MBD-flanking disordered domains (N-terminal domain, NTD, and intervening domain, ID) exert a considerable influence on the structural and functional features of the MBD (Claveria-Gimeno, R. et al. Sci Rep. 2017, 7, 41635), here we report the biophysical study of the influence of the protein scaffold on the structural and functional effect induced by these two RTT-associated mutations. These results represent an example of how a given mutation may show different effects (sometimes opposing effects) depending on the molecular context.This research was funded by the Spanish Ministry of Economy and Competitiveness and European ERDF Funds (MCIU/AEI/FEDER, EU) (BFU2016-78232-P to A.V.C.; BES-2017-080739 to D.O.A.); Miguel Servet Program from Instituto de Salud Carlos III (CPII13/00017 to O.A.); Fondo de Investigaciones Sanitarias from Instituto de Salud Carlos III and European Union (ERDF/ESF, “Investing in your future”) (PI15/00663 and PI18/00349 to O.A.); Diputación General de Aragón (Protein Targets and Bioactive Compounds Group E45_17R to A.V.C. and Digestive Pathology Group B25_17R to O.A.); and the Centro de Investigación Biomédica en Red en Enfermedades Hepáticas y Digestivas (CIBERehd).Peer reviewe

    Molecular context-dependent effects induced by rett syndrome-associated mutations in mecp2

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    Altres ajuts: This research was funded by the Diputación General de Aragón (Protein Targets and Bioactive Compounds Group E45_17R to A.V.C. and Digestive Pathology Group B25_17R to O.A.); and the Centro de Investigación Biomédica en Red en Enfermedades Hepáticas y Digestivas (CIBERehd).Methyl-CpG binding protein 2 (MeCP2) is a transcriptional regulator and a chromatinbinding protein involved in neuronal development and maturation. Loss-of-function mutations in MeCP2 result in Rett syndrome (RTT), a neurodevelopmental disorder that is the main cause of mental retardation in females. MeCP2 is an intrinsically disordered protein (IDP) constituted by six domains. Two domains are the main responsible elements for DNA binding (methyl-CpG binding domain, MBD) and recruitment of gene transcription/silencing machinery (transcription repressor domain, TRD). These two domains concentrate most of the RTT-associated mutations. R106W and R133C are associated with severe and mild RTT phenotype, respectively. We have performed a comprehensive characterization of the structural and functional impact of these substitutions at molecular level. Because we have previously shown that the MBD-flanking disordered domains (Nterminal domain, NTD, and intervening domain, ID) exert a considerable influence on the structural and functional features of the MBD (Claveria-Gimeno, R. et al. Sci Rep. 2017, 7, 41635), here we report the biophysical study of the influence of the protein scaffold on the structural and functional effect induced by these two RTT-associated mutations. These results represent an example of how a given mutation may show different effects (sometimes opposing effects) depending on the molecular context

    Altered Natural Killer Cell Function in HIV-Exposed Uninfected Infants

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    ObjectivesHIV-exposed uninfected (HEU) infants have higher rates of severe and fatal infections compared with HIV-unexposed (HUU) infants, likely due to immune perturbations. We hypothesized that alterations in natural killer (NK) cell activity might occur in HEU infants and predispose them to severe infections.DesignCase–control study using cryopreserved peripheral blood mononuclear cells (PBMCs) at birth and 6 months from HEU infants enrolled from 2002 to 2009 and HUU infants enrolled from 2011 to 2013.MethodsNK cell phenotype and function were assessed by flow cytometry after 20-h incubation with and without K562 cells.ResultsThe proportion of NK cells among PBMCs was lower at birth in 12 HEU vs. 22 HUU (1.68 vs. 10.30%, p < 0.0001) and at 6 months in 52 HEU vs. 72 HUU (3.09 vs. 4.65%, p = 0.0005). At birth, HEU NK cells demonstrated increased killing of K562 target cells (p < 0.0001) and increased expression of CD107a (21.65 vs. 12.70%, p = 0.047), but these differences resolved by 6 months. Stimulated HEU NK cells produced less interferon (IFN)γ at birth (0.77 vs. 2.64%, p = 0.008) and at 6 months (4.12 vs. 8.39%, p = 0.001), and showed reduced perforin staining at 6 months (66.95 vs. 77.30%, p = 0.0008). Analysis of cell culture supernatants indicated that lower NK cell activity in HEU was associated with reduced interleukin (IL)-12, IL-15, and IL-18. Addition of recombinant human IL-12 to stimulated HEU PBMCs restored IFNγ production to that seen in stimulated HUU cultures.ConclusionNK cell proportion, phenotype, and function are altered in HEU infants. NK cell cytotoxicity and degranulation are increased in HEU at birth, but HEU NK cells have reduced IFNγ and perforin production, suggesting an adequate initial response, but decreased functional reserve. NK cell function improved with addition of exogenous IL-12, implicating impaired production of IL-12 by accessory cells. Alterations in NK cell and accessory cell function may contribute to the increased susceptibility to infection in HEU infants

    Prevalence and Associated Characteristics of HIV-Infected Children in Latin America Who Know Their HIV Status

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    We estimated the prevalence of human immunodeficiency virus (HIV) disclosure in children from a prospective observational cohort study conducted at clinical sites in Brazil, Mexico, and Peru. Fewer than half of the children in this study knew their HIV status, which highlights the need for better strategies for disclosure that are age and culturally appropriate.Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentEunice Kennedy Shriver Natl Inst Child Hlth & Hum, NIH, Bethesda, MD USAUniv Nacl Mayor San Marcos, Inst Med Trop Daniel Carrion, Lima, PeruUniv Fed Sao Paulo, Escola Paulista Med, Sao Paulo, BrazilHosp Femina, Porto Alegre, RS, BrazilWestat Corp, Rockville, MD USAUniv Fed Sao Paulo, Escola Paulista Med, Sao Paulo, BrazilEKSNUCHHD: N01-HD-3-3345EKSNUCHHD: HHSN267200800001CEKSNUCHHD: HHSN275201300003CWeb of Scienc

    Missed opportunities for prevention of mother-to-child transmission of HIV-1 in the NISDI Perinatal and LILAC cohorts

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    Presentes no NISDI Perinatal: Beatriz Grinsztejn; Valdiléa Veloso (Fundação Oswaldo Cruz. Instituto Nacional de Infectologia Evandro Chagas. Laboratório de Pesquisa Clínica em DST/AIDS. Rio de Janeiro, RJ, Brasil).Submitted by Fábio Marques ([email protected]) on 2018-11-07T17:49:40Z No. of bitstreams: 1 Missed opportunities for prevention_Beatriz_Grinsztejn_INI_LapClin-AIDS_2012.pdf: 93703 bytes, checksum: 255b016f6919f81ff71e5fdecdb0aee8 (MD5)Approved for entry into archive by Regina Costa ([email protected]) on 2018-11-16T15:14:25Z (GMT) No. of bitstreams: 1 Missed opportunities for prevention_Beatriz_Grinsztejn_INI_LapClin-AIDS_2012.pdf: 93703 bytes, checksum: 255b016f6919f81ff71e5fdecdb0aee8 (MD5)Made available in DSpace on 2018-11-16T15:14:25Z (GMT). No. of bitstreams: 1 Missed opportunities for prevention_Beatriz_Grinsztejn_INI_LapClin-AIDS_2012.pdf: 93703 bytes, checksum: 255b016f6919f81ff71e5fdecdb0aee8 (MD5) Previous issue date: 2012Pediatric, Adolescent, and Maternal AIDS Branch, CRMC, NICHD, NIH, DHHS. Bethesda, USA.Westat. Rockville, Maryland, USA.Westat. Rockville, Maryland, USA.Universidade Federal do Rio de Janeiro. Hospital Clementino Fraga. Serviço de Doenças Infecciosas. Rio de Janeiro, RJ, Brasil.Universidade de São Paulo. Faculdade de Medicina de Ribeirão Preto. Ribeirão Preto, SP, Brasil.Hospital Dra. Cecilia Grierson. Unidad de Enfermedades Infecciosas. Buenos Aires, Argentina.Nossa Senhora da Conceição Hospital. Serviço de Doenças Infecciosas. Porto Alegre, Brasil.Universidade Federal de São Paulo. Faculdade Paulista de Medicina. Departamento de Pediatria. São Paulo, Brasil.Hospital Geral de Nova Iguaçu. HIV Family Care Clinic./ Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de AIDS e Imunologia Molecular. Rio de Janeiro, Brasil.Universidad Nacional Mayor de San Marcos. D.A. Instituto Carrión de Medicina Tropical. Sección de Epidemiología. Lima, Perú.Irmandade da Santa Casa de Misericordia de Porto Alegre. Porto Alegre, Brasil.OBJECTIVE: To evaluate cases of mother-to-child transmission of HIV-1 at multiple sites in Latin America and the Caribbean in terms of missed opportunities for prevention. METHODS: Pregnant women infected with HIV-1 were eligible for inclusion if they were enrolled in either the NISDI Perinatal or LILAC protocols by October 20, 2009, and had delivered a live infant with known HIV-1 infection status after March 1, 2006. RESULTS: Of 711 eligible mothers, 10 delivered infants infected with HIV-1. The transmission rate was 1.4% (95% CI, 0.7-2.6). Timing of transmission was in utero or intrapartum (n=5), intrapartum (n=2), intrapartum or early postnatal (n=1), and unknown (n=2). Possible missed opportunities for prevention included poor control of maternal viral load during pregnancy; late initiation of antiretrovirals during pregnancy; lack of cesarean delivery before labor and before rupture of membranes; late diagnosis of HIV-1 infection; lack of intrapartum antiretrovirals; and incomplete avoidance of breastfeeding. CONCLUSION: Early knowledge of HIV-1 infection status (ideally before or in early pregnancy) would aid timely initiation of antiretroviral treatment and strategies designed to prevent mother-to-child transmission. Use of antiretrovirals must be appropriately monitored in terms of adherence and drug resistance. If feasible, breastfeeding should be completely avoided. Presented in part at the XIX International AIDS Conference (Washington, DC; July 22-27, 2012); abstract WEPE163
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