Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
1.
Clin Infect Dis ; 75(8): 1370-1378, 2022 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-35218356

RESUMO

BACKGROUND: The world is set on the eradication of measles. Continuation of the measles vaccine (MV) after eradication could still reduce morbidity because the MV has so-called beneficial nonspecific effects. We evaluated the effect of a "booster" dose of the MV on overall severe morbidity. METHODS: We conducted a randomized controlled trial among children aged 17.5 to 48 months in Guinea-Bissau, where the MV is recommended only at 9 months of age. At the time of this interim analysis, 3164 children had been allocated 1:1 to a second dose of measles vaccine (MV2) at 18 months of age or to no vaccine. Severe morbidity (a composite outcome of nonaccidental deaths and hospital admissions) rate ratios (SMRRs) were calculated by Cox regression analysis censored for national oral polio vaccine (OPV) campaigns. RESULTS: There were no measles cases during the trial period. There were 43 nonaccidental deaths or hospital admissions during follow-up. Severe morbidity was 2.6 per 100 person-years in the MV2 group and 3.6 per 100 person-years among controls; hence, the estimated effect of MV2 on severe morbidity was 28% (SMRR, 0.72; 95% confidence interval [CI], .38-1.38). At 12 months of follow-up, the number needed to treat to prevent 1 severe morbidity event was 137 children. After OPV campaigns, the estimated effect of MV2 was reduced to 9% (SMRR, 0.91; 95% CI, .46-1.81). CONCLUSIONS: MV2 may reduce nonmeasles severe morbidity by 28% (-38% to 62%), although this did not achieve statistical significance in this study. If significant in higher powered studies, this has major implications for child health, even after measles eradication. CLINICAL TRIALS REGISTRATION: NCT02943681.


Assuntos
Vacina contra Sarampo , Sarampo , Criança , Guiné-Bissau/epidemiologia , Hospitais , Humanos , Lactente , Sarampo/prevenção & controle , Vacina Antipólio Oral
3.
PLoS One ; 15(11): e0242507, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33253198

RESUMO

Asymptomatic malaria infections may affect red blood cell (RBC) homeostasis. Reports indicate a role for chronic hemolysis and splenomegaly, however, the underlying processes are incompletely understood. New hematology analysers provide parameters for a more comprehensive analysis of RBC hemostasis. Complete blood counts were analysed in subjects from all age groups (n = 1118) living in a malaria hyperendemic area and cytokines and iron biomarkers were also measured. Subjects were divided into age groups (<2 years, 2-4, 5-14 and ≥15 years old) and clinical categories (smear-negative healthy subjects, asymptomatic malaria and clinical malaria). We found that hemoglobin levels were similar in smear-negative healthy children and asymptomatic malaria children but significantly lower in clinical malaria with a maximum difference of 2.2 g/dl in children <2 years decreasing to 0.1 g/dl in those aged ≥15 years. Delta-He, presenting different hemoglobinization of reticulocytes and RBC, levels were lower in asymptomatic and clinial malaria, indicating a recent effect of malaria on erythropoiesis. Reticulocyte counts and reticulocyte production index (RPI), indicating the erythropoietic capacity of the bone marrow, were higher in young children with malaria compared to smear-negative subjects. A negative correlation between reticulocyte counts and Hb levels was found in asymptomatic malaria (ρ = -0.32, p<0.001) unlike in clinical malaria (ρ = -0.008, p = 0.92). Free-Hb levels, indicating hemolysis, were only higher in clinical malaria. Phagocytozing monocytes, indicating erythophagocytosis, were highest in clinical malaria, followed by asymptomatic malaria and smear-negative subjects. Circulating cytokines and iron biomarkers (hepcidin, ferritin) showed similar patterns. Pro/anti-inflammatory (IL-6/IL-10) ratio was higher in clinical than asymptomatic malaria. Cytokine production capacity of ex-vivo whole blood stimulation with LPS was lower in children with asymptomatic malaria compared to smear-negative healthy children. Bone marrow response can compensate the increased red blood cell loss in asymptomatic malaria, unlike in clinical malaria, possibly because of limited level and length of inflammation. Trial registration: Prospective diagnostic study: ClinicalTrials.gov identifier: NCT02669823. Explorative cross-sectional field study: ClinicalTrials.gov identifier: NCT03176719.


Assuntos
Eritrócitos/patologia , Malária/sangue , Adolescente , Adulto , Infecções Assintomáticas , Burkina Faso/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Eritrócitos/citologia , Feminino , Homeostase , Humanos , Malária/diagnóstico , Malária/patologia , Masculino , Estudos Prospectivos , Adulto Jovem
4.
J Pediatric Infect Dis Soc ; 9(2): 166-172, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-30715451

RESUMO

BACKGROUND AND HYPOTHESIS: Maternal priming might enhance the beneficial nonspecific effects (NSEs) of live measles vaccination (MV). Children with a bacillus Calmette-Guérin (BCG) vaccine scar have a lower mortality rate than those without a scar that is not explained by protection against tuberculosis. We examined the hypothesis that BCG scarring would have a stronger effect on a child if the mother also had a BCG scar. METHODS: In a randomized controlled trial (RCT) of early MV in children aged 4.5 months, the BCG-scar status of the children and their mother were registered at enrollment at 4.5 months of age. The children were followed up until they were 36 months of age. Using a Cox proportional hazards model, we compared mortality rate ratios according to maternal and child BCG-scar status after adjusting for where the BCG vaccine was given (the national hospital or elsewhere). We censored for other interventions that have immunomodulating effects on child survival, including neonatal vitamin A supplementation and early MV. RESULTS: A total of 2213 children had not received neonatal vitamin A supplementation and early MV; 83% of these children and 44% of the mothers had a BCG scar. Children whose mother had a BCG scar were not more likely to have a BCG scar than those whose mother did not have a BCG scar (risk ratio, 1.01 [95% confidence interval (CI), 0.98-1.05]). Among the children, having a BCG scar was associated with a 41% (95% CI, 5%-64%) lower mortality between the ages of 4.5 and 36 months. The reduction in mortality was 66% (95% CI, 33%-83%) if the mother also had a BCG scar but only 8% (95% CI, -83% to 53%) if the mother had no BCG scar (test of interaction, P = .04). CONCLUSIONS: Maternal BCG priming might be important for the effect of BCG vaccination on child survival. Ensuring better BCG vaccine scarring among mothers and children could have a considerable effect on child mortality levels.


Assuntos
Vacina BCG , Mortalidade da Criança , Cicatriz , Vacinação , Pré-Escolar , Feminino , Seguimentos , Guiné-Bissau/epidemiologia , Humanos , Lactente , Masculino , Mães , Modelos de Riscos Proporcionais , Tuberculose/prevenção & controle , Vacinação/estatística & dados numéricos
5.
Biochim Biophys Acta Biomembr ; 1862(3): 183155, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31846645

RESUMO

At concentrations exceeding 10 µM, arginine-rich cell-penetrating peptides (CPPs) trigger a rapid cytoplasmic import that involves activation of acid sphingomyelinase (ASMase). ASMase activation occurs through a variety of stress signals and has also been related to the reorganization of membrane microdomains during entry of pathogens. However, in none of these cases has the initial trigger for ASMase activation been established on a molecular level. We here show that rapid cytosolic CPP import depends upon an increase in intracellular calcium, likely caused by modulation of the Orai1 calcium channel. At low peptide concentration, cytoplasmic import could be induced by thapsigargin, a known activator of Orai1. Compounds known to block Orai1 inhibited rapid uptake. Peptide-mediated modulation of Orai1 involved cell surface sialic acids as inhibition of sialylation as well as chemical blocking of sialic acids reduced rapid cytoplasmic uptake, which could be reconstituted by thapsigargin. These results establish a link between the known propensity of arginine-rich CPPs to interact with the glycocalyx and calcium influx as the initial step triggering direct cytosolic peptide uptake.


Assuntos
Peptídeos Penetradores de Células/metabolismo , Proteína ORAI1/metabolismo , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Sinalização do Cálcio/fisiologia , Cátions/metabolismo , Membrana Celular/metabolismo , Peptídeos Penetradores de Células/fisiologia , Citosol , Células HeLa , Humanos , Proteína ORAI1/fisiologia , Esfingomielina Fosfodiesterase/metabolismo , Tapsigargina/farmacologia
6.
J Rheumatol ; 44(9): 1325-1330, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28668802

RESUMO

OBJECTIVE: To determine whether anticyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factor (RF) are risk factors for 10-year cardiovascular disease (CVD) in patients with rheumatoid arthritis (RA). METHODS: Analyses were performed using data from the Nijmegen early RA inception cohort, in which patients with newly diagnosed RA, consecutively included since 1985, were regularly followed up. Anti-CCP and RF were determined at baseline (diagnosis). Outcome was the first cardiovascular disease (CVD) event [ischemic heart disease, nonhemorrhagic cerebrovascular accident (CVA), or peripheral artery disease (PAD)] after baseline as retrieved from physician diagnosis. Fatality was checked against death certificates. Cox regression including correction for baseline confounders was performed to estimate the effect of anti-CCP, RF, and their interaction on 10-year CVD-free survival. RESULTS: Of 929 patients included, 628 were anti-CCP-positive and 697 were RF-positive. During followup, with a median of 7.5 years, 162 CV events were observed (101 ischemic heart disease, 45 CVA, and 16 PAD), of which 15 were fatal. The HRadjusted for anti-CCP was 1.17 (95% CI 0.82-1.67) and the HRadjusted for RF was 1.52 (95% CI 1.00-2.30). The association of RF positivity with CVD was even stronger in the anti-CCP-negative patients: HRadjusted 2.09 (95% CI 1.18-3.71). There was no significant interaction (p = 0.098) between anti-CCP and RF. CONCLUSION: Rather than anti-CCP, presence of RF was associated with CVD in this cohort of patients with RA.


Assuntos
Anticorpos Antiproteína Citrulinada/sangue , Artrite Reumatoide/complicações , Doenças Cardiovasculares/etiologia , Fator Reumatoide/sangue , Adulto , Idoso , Artrite Reumatoide/sangue , Artrite Reumatoide/imunologia , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/imunologia , Estudos de Coortes , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
7.
EBioMedicine ; 8: 341-348, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27428443

RESUMO

BACKGROUND: Bacillus Calmette-Guérin (BCG) vaccination possesses effects on health beyond its target disease, the so called "non-specific effects". We evaluate these effects, as well as the effect of timing of BCG and other vaccinations, on stunting in Sub-Saharan African (SSA) children under five. METHODS: We use a Big Data design, including cross-sectional data for 368,450 children from 33 SSA countries. Logistic regression analysis is used with control factors at child, mother, household and context level. RESULTS: Overall, BCG vaccination did not affect stunting in SSA children (OR 1.00 [0.98-1.03]). Timing of BCG vaccination was of importance (ßtime=0.067 [0.061-0.073]): compared to unvaccinated children, BCG was associated with lower odds on stunting for children vaccinated early in life (OR 0.92 [0.89-0.94]) and higher odds for children vaccinated later in infancy (OR 1.64 [1.53-1.76]). Similar findings were done for diphtheria-tetanus-pertussis (DTP)1 and measles vaccination, and when hemoglobin concentration was used as outcome variable. CONCLUSIONS: We found a general time-dependent pattern of non-specific effects of vaccination, with positive associations for vaccinations given early in life and negative associations for vaccinations given later in infancy. If confirmed in further research, our findings may provide a new perspective on the non-specific effects of vaccination.


Assuntos
Transtornos do Crescimento/epidemiologia , Transtornos do Crescimento/etiologia , Vacinação , Vacinas , África Subsaariana/epidemiologia , Pré-Escolar , Estudos Transversais , Feminino , Geografia , Humanos , Lactente , Recém-Nascido , Masculino , Razão de Chances , Vigilância da População , Prevalência , Estudos Retrospectivos , Fatores de Tempo , Vacinação/efeitos adversos , Vacinas/efeitos adversos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...