Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Source
    • Language
377 result(s) for "Figueiredo, Camila A."
Sort by:
Uncovering genetic mechanisms associated with harmful use of alcohol in admixed Latin Americans
Background Harmful use of alcohol (HUA) refers to drinking patterns that are associated with increased risk of medical complications and adverse social impacts. HUA is a multifactorial condition, involving neurotransmission system alterations, environmental factors, and genetic predisposition. Previous studies have identified numerous genetic variants associated with alcohol-related phenotypes. However, the generalizability of these findings remains limited, as most studies have primarily focused on European and Asian populations, leaving other ethnic groups, such as Latino Americans, underrepresented. Here, we explored the genetic mechanisms underlying HUA in admixed Brazilians. HUA was evaluated in 2,840 individuals using the Alcohol Use Disorder Identification Test (AUDIT). Genetic variations were assessed using a genome-wide genotyping array, followed by genotype imputation. Ancestry patterns were estimated by comparing individual variants with those of reference populations. Association analysis was performed using multivariate logistic regression, and the functional impacts of variants were investigated through in silico analysis. Pathway enrichment and network analyses were conducted to identify potential genetic mechanisms underlying HUA. Results Ancestry analysis confirmed the admixed nature of the study population, with lower levels of European ancestry significantly associated ( p  < 0.05, Mann-Whitney U test) with increased risk of HUA, suggesting potential ancestry-related genetic or socio-environmental factors contributing to alcohol-related behaviors. The genome-wide association study identified a significant association between the variant rs1097611 at 1p33 and HUA p  = 4.88 × 10 -8 , odds ratio [OR] = 1.8, confidence interval [CI] = 1.46–2.23), based on a multivariate logistic regression model assuming additive genetic effects and adjusted for sex and European ancestry. The rs1097611 and other variants at this locus are located in regulatory regions and have been previously associated with differential CYP4B1 expression across multiple tissues. Other suggestive association signals (5 × 10 -8 < p < 10 − 5 ) were identified at loci previously implicated in addictive substance use behaviors, including alcohol and/or tobacco consumption, such as 10q21.2 ( ARID5B ), 5q34-q35.1 ( SLIT3 ), and 10q11.23 ( SGMS1 ). Genome-based pathway enrichment analysis revealed several mechanisms potentially involved in HUA, primarily related to neurobiological processes and neuronal signaling. Finally, network analysis revealed a highly interconnected cluster of nervous system-related pathways, pointing to their potential functional interplay. Conclusions This study identifies novel loci, particularly at 1p33 ( CYP4B1 ), and genetic mechanisms potentially involved in HUA in an admixed Latin American population. Studies in diverse ethnic groups are crucial to uncover novel genetic risk variants for HUA and improve its management.
Causes and MEchanisms foR non-atopic Asthma in Children (CAMERA) study: rationale and protocol
Background The Causes And MEchanisms foR non-atopic Asthma in children (CAMERA) study was designed to investigate risk factors and mechanisms of non-atopic asthma in children and young adults in Brazil, Ecuador, Uganda, and New Zealand. Initial epidemiological analyses using existing datasets identified and compared risk factors for both atopic and non-atopic asthma. The focus of this paper is the protocol for sample collection and analysis of clinical data on possible non-atopic mechanisms. Methods In each of the four centres, the CAMERA study will enroll 160 participants aged 10–28 years, equally distributed among atopic asthmatics (AA), non-atopic asthmatics (NAA), atopic non-asthmatics and non-atopic non-asthmatics. Participants will be new recruits or returning World ASthma Phenotypes (WASP) study participants. Phase I consists of skin prick tests to define atopy, a general CAMERA questionnaire that covers respiratory and general health to identify asthma cases, followed by an asthma control questionnaire for asthmatics only. Phase II consists of a stress questionnaire and the following clinical assessments: lung function, nasal cytology, blood sampling, in vitro whole blood stimulation to assess IFN-γ production, hair cortisol concentration, dry air and capsaicin challenges, plus in a subset, cold air challenges. Analyses will compare inflammatory, physiological and clinical parameters across the four groups overall and by country. Discussion Here, we present the protocol for the CAMERA study, to provide relevant methodological details for CAMERA publications and to allow other centres globally to conduct similar analyses. The findings of this mechanistic multi-centre study will inform new and phenotype-specific prevention and treatment approaches. Clinical trial number Not applicable.
Detection of cytokines in cervicovaginal lavage in HIV-infected women and its association with high-risk human papillomavirus
Women living with HIV/AIDS (WLHA) have an increased prevalence of high-risk HPV infection (HR-HPV) and cervical intraepithelial neoplasia (CIN) and a greater risk of cervical cancer despite access to a new generation of antiretroviral therapy. The aim of this study is to evaluate the concentrations of different cytokines involved in the local immune response in WLHA, which is fundamental for understanding the pathogenesis of HPV-related cancer in this population. IL-1β, IL-2, IL-4, IL-6, IL-10, IFN-γ, TNF-α, IP-10, GM-CSF, and MIP-1α were investigated in the cervicovaginal lavage (CVL) of 106 WLHA attending at Hospital Universitario Professor Edgard Santos in Salvador, Bahia, Brazil, during the period December 2019 to April 2023 by Luminex . All participants were also tested for and and underwent colposcopy, Pap smear, and Nugent score. HIV plasma viral load (VL) and CD4 cell count were performed for all WLHA. In this study, 22.6% (24/106) of WLHA were infected with HR-HPV. A higher proportion of patients with HR-HPV (66.7%) had detectable levels of IL-10 than those negative ones (40.2%, = 0.02). More premenopausal women had either IL-6 (51.4%) or IP-10 (58.3%) than those in menopausal status (26.5% for IL-6 and 32.4% for IP-10, = 0.013 and = 0.011, respectively). Vaginosis was negatively associated with detection of IP-10 (24.2% vs. 61.4%, < 0.001) and INF-γ (39.4% vs. 68.6%, = 0.005). A positive association was detected for IL-1β (66.7 vs. 37.1%, = 0.005) and IL-10 (63.6% vs. 37.1%, = 0.01). VL and CD4 were not associated with the studied cytokines. We demonstrated a positive association between IL-10 and HPV infection in CVL, suggesting the predominance of the Th2 response in HIV/HPV co-infected patients. However, further studies with longer follow-up will be needed to evaluate the association of IL-10 with HPV infection, CIN, and cervical cancer in WLHA.
Single nucleotide variants in the IL33 and IL1RL1 (ST2) genes are associated with periodontitis and with Aggregatibacter actinomycetemcomitans in the dental plaque biofilm: A putative role in understanding the host immune response in periodontitis
The Interleukin (IL)-33 is important in several inflammatory diseases and its cellular receptor is the Interleukin 1 receptor-like 1 (IL1RL1), also called suppression of tumorigenicity 2 ligand (ST2L). This study investigated associations between single nucleotide variants (SNVs) in the IL33 gene and in the IL1RL1 (ST2) gene with periodontitis. Additionally, aimed to determine the role of Aggregatibacter actinomycetemcomitans ( Aa ) relative amount in the subgingival biofilm in these associations. A cross-sectional study was carried out with 506 individuals that answered a structured questionnaire used to collect their health status, socioeconomic-demographic, and behavioral characteristics. Periodontal examination was performed to determine the presence and severity of periodontitis, and subgingival biofilm samples were collected to quantify the relative amount of Aa by real time polymerase chain reaction. Human genomic DNA was extracted from whole blood cells and SNV genotyping was performed. Logistic regression estimated the association measurements, odds ratio (OR), and 95% confidence interval (95%CI), between the IL33 and ST2 genes with periodontitis, and subgroup analyses assessed the relative amount of Aa in these associations. 23% of individuals had periodontitis. Adjusted measurements showed a statistically significant inverse association between two SNVs of the ST2; rs148548829 (C allele) and rs10206753 (G allele). These two alleles together with a third SNV, the rs11693204 (A allele), were inversely associated with moderate periodontitis. One SNV of the IL33 gene also showed a statistically significant inverse association with moderate periodontitis. Nine SNVs of the ST2 gene were inversely associated with the relative amount of Aa . In the high Aa subgroup, there was a direct association between 11 SNVs of the ST2 gene and moderate periodontitis and two SNVs of the ST2 gene and severe periodontitis, and eight SNVs of the ST2 gene and periodontitis. These exploratory findings of genetic variants in IL-33/ST2 axis support the concept that the different tissue responses among individuals with periodontitis may be modulated by the host’s genetics, influencing the physiopathology of the disease.
Factors associated with asthma attack recurrence in Ecuadorian children: longitudinal study of potential impact of the COVID-19 pandemic lockdown
BackgroundThe COVID-19 pandemic caused a major disruption in access to and use of health resources and facilities. There are limited longitudinal data from low-resource settings on the impact of pandemic mitigation strategies and medication use on asthma attacks in children.MethodsWe did a longitudinal study of risk factors for asthma attack recurrence among children aged 5–17 years presenting with an attack to emergency rooms in public hospitals in Ecuador. Children were followed for at least 12 months by monthly telemonitoring. Cox regression models for multiple recurrences were used to identify potential risk factors.Results213 asthmatic children were recruited from May 2019 to March 2020 when recruitment was interrupted by a COVID-19 lockdown: 97% were followed for at least 12 months (median 419 days, IQRs 393–421 days). In multivariable analysis, the lockdown effect (adjusted HR 0.35, 95% CI 0.22 to 0.56, p<0.001) and use of inhaled corticosteroids (adjusted HR 0.64, 95% CI 0.43 to 0.93, p=0.020) were strongly protective against recurrence while short-acting β2 agonist use was associated with increased recurrence, particularly among children with a previous asthma diagnosis (interaction p=0.033). Other risk factors were household mould (adjusted HR 1.42, 95% CI 1.03 to 1.95, p=0.031) and number of prerecruitment emergency room visits (adjusted HR 1.05, 95% CI 1.00 to 1.11, p=0.040).ConclusionOur data show in a population of asthmatic children from marginalised urban neighbourhoods in Ecuador, that use of inhaled corticosteroids was protective against asthma attack recurrence as were mitigation strategies implemented during the COVID-19 pandemic to reduce transmission of respiratory viruses.
Understanding and controlling asthma in Latin America: A review of recent research informed by the SCAALA programme
Asthma is an important health concern in Latin America (LA) where it is associated with variable prevalence and disease burden between countries. High prevalence and morbidity have been observed in some regions, particularly marginalized urban populations. Research over the past 10 years from LA has shown that childhood disease is primarily non‐atopic. The attenuation of atopy may be explained by enhanced immune regulation induced by intense exposures to environmental factors such as childhood infections and poor environmental conditions of the urban poor. Non‐atopic symptoms are associated with environmental and lifestyle factors including poor living conditions, respiratory infections, psychosocial stress, obesity, and a diet of highly processed foods. Ancestry (particularly African) and genetic factors increase asthma risk, and some of these factors may be specific to LA settings. Asthma in LA tends to be poorly controlled and depends on access to health care and medications. There is a need to improve management and access to medication through primary health care. Future research should consider the heterogeneity of asthma to identify relevant endotypes and underlying causes. The outcome of such research will need to focus on implementable strategies relevant to populations living in resource‐poor settings where the disease burden is greatest.
Arterial Hypertension and Skin Allergy Are Risk Factors for Progression from Dengue to Dengue Hemorrhagic Fever: A Case Control Study
Currently, knowledge does not allow early prediction of which cases of dengue fever (DF) will progress to dengue hemorrhagic fever (DHF), to allow early intervention to prevent progression or to limit severity. The objective of this study is to investigate the hypothesis that some specific comorbidities increase the likelihood of a DF case progressing to DHF. A concurrent case-control study, conducted during dengue epidemics, from 2009 to 2012. Cases were patients with dengue fever that progressed to DHF, and controls were patients of dengue fever who did not progress to DHF. Logistic regression was used to estimate the association between DHF and comorbidities. There were 490 cases of DHF and 1,316 controls. Among adults, progression to DHF was associated with self-reported hypertension (OR = 1.6; 95% CI 1.1-2.1) and skin allergy (OR = 1.8; 95% CI 1.1-3.2) with DHF after adjusting for ethnicity and socio-economic variables. There was no statistically significant association between any chronic disease and progression to DHF in those younger than 15 years. Physicians attending patients with dengue fever should keep those with hypertension or skin allergies in health units to monitor progression for early intervention. This would reduce mortality by dengue.
Dissociation between skin test reactivity and anti-aeroallergen IgE: Determinants among urban Brazilian children
The dissociation between specific IgE and skin prick test reactivity to aeroallergens, a common finding in populations living in low and middle-income countries, has important implications for the diagnosis and treatment of allergic diseases. Few studies have investigated the determinants of this dissociation. In the present study, we explored potential factors explaining this dissociation in children living in an urban area of Northeast Brazil, focusing in particular on factors associated with poor hygiene. Of 1445 children from low income communities, investigated for risk factors of allergies, we studied 481 with specific IgE antibodies to any of Blomia tropicalis, Dermatophagoides pteronyssinus, Periplaneta americana and Blatella germanica allergens. Data on demographic, environmental and social exposures were collected by questionnaire; serum IgG and stool examinations were done to detect current or past infections with viral, bacterial, protozoan and intestinal helminth pathogens. We measured atopy by skin prick testing (SPT) and specific IgE (sIgE) to aerollergens in serum (by ImmunoCAP). SIgE reactivity to B. tropicalis extract depleted of carbohydrates was measured by an in-house ELISA. Total IgE was measured by in house capture ELISA. SNPs were typed using Illumina Omni 2.5. Negative skin prick tests in the presence of specific IgE antibodies were frequent. Factors independently associated with a reduced frequency of positive skin prick tests were large number of siblings, the presence of IgG to herpes simplex virus, Ascaris lumbricoides and Trichuris trichiura infections, living in neighborhoods with infrequent garbage collection, presence of rodents and cats in the household and sIgE reactivity to glycosylated B. tropicalis allergens. Also, SNP on IGHE (rs61737468) was negatively associated with SPT reactivity. A variety of factors were found to be associated with decreased frequency of SPT such as unhygienic living conditions, infections, total IgE, IgE response to glycosylated allergens and genetic polymorphisms, indicating that multiple mechanisms may be involved. Our data, showing that exposures to an unhygienic environment and childhood infections modulate immediate allergen skin test reactivity, provide support for the \"hygiene hypothesis\".
Genome-wide burden and association analyses implicate copy number variations in asthma risk among children and young adults from Latin America
The genetic architecture of asthma was relatively well explored. However, some work remains in the field to improve our understanding on asthma genetics, especially in non-Caucasian populations and with regards to commonly neglected genetic variants, such as Copy Number Variations (CNVs). In the present study, we investigated the contribution of CNVs on asthma risk among Latin Americans. CNVs were inferred from SNP genotyping data. Genome wide burden and association analyses were conducted to evaluate the impact of CNVs on asthma outcome. We found no significant difference in the numbers of CNVs between asthmatics and non-asthmatics. Nevertheless, we found that CNVs are larger in patients then in healthy controls and that CNVs from cases intersect significantly more genes and regulatory elements. We also found that a deletion at 6p22.1 is associated with asthma symptoms in children from Salvador (Brazil) and in young adults from Pelotas (Brazil). To support our results, we conducted an in silico functional analysis and found that this deletion spans several regulatory elements, including two promoter elements active in lung cells. In conclusion, we found robust evidence that CNVs could contribute for asthma susceptibility. These results uncover a new perspective on the influence of genetic factors modulating asthma risk.
Effect of Allium cepa L. on Lipopolysaccharide-Stimulated Osteoclast Precursor Cell Viability, Count, and Morphology Using 4',6-Diamidino-2-phenylindole-Staining
Allium cepa L. is known to possess numerous pharmacological properties. Our aim was to examine the in vitro effects of Allium cepa L. extract (AcE) on Porphyromonas gingivalis LPS and Escherichia coli LPS-stimulated osteoclast precursor cells to determine cell viability to other future cell-based assays. Osteoclast precursor cells (RAW 264.7) were stimulated by Pg LPS (1 μg/mL) and E. coli LPS (1 μg/mL) in the presence or absence of different concentrations of AcE (10–1000 μg/mL) for 5 days at 37°C/5% CO2. Resazurin reduction and total protein content assays were used to detect cell viability. AcE did not affect cell viability. Resazurin reduction assay showed that AcE, at up to 1000 μg/mL, did not significantly affect cell viability and cellular protein levels. Additionally a caspase 3/7 luminescence assay was used to disclose apoptosis and there was no difference in apoptotic activity between tested groups and control group. Fluorescence images stained by DAPI showed no alteration on the morphology and cell counts of LPS-stimulated osteoclast precursor cells with the use of AcE in all tested concentrations when compared to control. These findings suggest that Allium cepa L. extract could be used for in vitro studies on Porphyromonas gingivalis LPS and Escherichia coli LPS-stimulated osteoclast precursor cells.