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Aneuploidy is widely observed in both unicellular and multicellular eukaryotes, usually associated with adaptation to stress conditions. Chromosomal duplication stability is a tradeoff between the fitness cost of having unbalanced gene copies and the potential fitness gained from increased dosage of specific advantageous genes. Trypanosomatids, a family of protozoans that include species that cause neglected tropical diseases, are a relevant group to study aneuploidies. Their life cycle has several stressors that could select for different patterns of chromosomal duplications and/or losses, and their nearly universal use of polycistronic transcription increases their reliance on gene expansion/contraction, as well as post-transcriptional control as mechanisms for gene expression regulation. By evaluating the data from 866 isolates covering seven trypanosomatid genera, we have revealed that aneuploidy tolerance is an ancestral characteristic of trypanosomatids but has a reduced occurrence in a specific monophyletic clade that has undergone large genomic reorganization and chromosomal fusions. We have also identified an ancient chromosomal duplication that was maintained across these parasite's speciation, named collectively as the trypanosomatid ancestral supernumerary chromosome (TASC). TASC has most genes in the same coding strand, is expressed as a disomic chromosome (even having four copies), and has increased potential for functional variation, but it purges highly deleterious mutations more efficiently than other chromosomes. The evidence of stringent control over gene expression in this chromosome suggests that these parasites have adapted to mitigate the fitness cost associated with this ancient chromosomal duplication.
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Aneuploidia , Duplicação Cromossômica , Regulação da Expressão Gênica , Genoma de Protozoário , Evolução Molecular , Trypanosomatina/genética , FilogeniaRESUMO
Addressing the challenges of quiescence and post-treatment relapse is of utmost importance in the microbiology field. This study shows that Leishmania infantum and L. donovani parasites rapidly enter into quiescence after an estimated 2-3 divisions in both human and mouse bone marrow stem cells. Interestingly, this behavior is not observed in macrophages, which are the primary host cells of the Leishmania parasite. Transcriptional comparison of the quiescent and non-quiescent metabolic states confirmed the overall decrease of gene expression as a hallmark of quiescence. Quiescent amastigotes display a reduced size and signs of a rapid evolutionary adaptation response with genetic alterations. Our study provides further evidence that this quiescent state significantly enhances resistance to treatment. Moreover, transitioning through quiescence is highly compatible with sand fly transmission and increases the potential of parasites to infect cells. Collectively, this work identified stem cells in the bone marrow as a niche where Leishmania quiescence occurs, with important implications for antiparasitic treatment and acquisition of virulence traits.
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Células-Tronco Hematopoéticas , Leishmania infantum , Animais , Células-Tronco Hematopoéticas/parasitologia , Células-Tronco Hematopoéticas/metabolismo , Camundongos , Humanos , Leishmania donovani/fisiologia , Macrófagos/parasitologia , Macrófagos/metabolismo , Leishmaniose Visceral/parasitologia , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos BALB CRESUMO
In Brazil, Leishmania braziliensis is the main causative agent of the neglected tropical disease, cutaneous leishmaniasis (CL). CL presents on a spectrum of disease severity with a high rate of treatment failure. Yet the parasite factors that contribute to disease presentation and treatment outcome are not well understood, in part because successfully isolating and culturing parasites from patient lesions remains a major technical challenge. Here we describe the development of selective whole genome amplification (SWGA) for Leishmania and show that this method enables culture-independent analysis of parasite genomes obtained directly from primary patient skin samples, allowing us to circumvent artifacts associated with adaptation to culture. We show that SWGA can be applied to multiple Leishmania species residing in different host species, suggesting that this method is broadly useful in both experimental infection models and clinical studies. SWGA carried out directly on skin biopsies collected from patients in Corte de Pedra, Bahia, Brazil, showed extensive genomic diversity. Finally, as a proof-of-concept, we demonstrated that SWGA data can be integrated with published whole genome data from cultured parasite isolates to identify variants unique to specific geographic regions in Brazil where treatment failure rates are known to be high. SWGA provides a relatively simple method to generate Leishmania genomes directly from patient samples, unlocking the potential to link parasite genetics with host clinical phenotypes.
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Genoma de Protozoário , Leishmaniose Cutânea , Parasitologia , Pele , Genoma de Protozoário/genética , Humanos , Genética Populacional , Pele/parasitologia , Brasil , Leishmaniose Cutânea/parasitologia , Parasitologia/métodos , Leishmania braziliensis/genéticaRESUMO
BACKGROUND: Gene families are groups of homologous genes that often have similar biological functions. These families are formed by gene duplication events throughout evolution, resulting in multiple copies of an ancestral gene. Over time, these copies can acquire mutations and structural variations, resulting in members that may vary in size, motif ordering and sequence. Multigene families have been described in a broad range of organisms, from single-celled bacteria to complex multicellular organisms, and have been linked to an array of phenomena, such as host-pathogen interactions, immune evasion and embryonic development. Despite the importance of gene families, few approaches have been developed for estimating and graphically visualizing their diversity patterns and expression profiles in genome-wide studies. RESULTS: Here, we introduce an R package named dgfr, which estimates and enables the visualization of sequence divergence within gene families, as well as the visualization of secondary data such as gene expression. The package takes as input a multi-fasta file containing the coding sequences (CDS) or amino acid sequences from a multigene family, performs a pairwise alignment among all sequences, and estimates their distance, which is subjected to dimension reduction, optimal cluster determination, and gene assignment to each cluster. The result is a dataset that allows for the visualization of sequence divergence and expression within the gene family, an approximation of the number of clusters present in the family. CONCLUSIONS: dgfr provides a way to estimate and study the diversity of gene families, as well as visualize the dispersion and secondary profile of the sequences. The dgfr package is available at https://github.com/lailaviana/dgfr under the GPL-3 license.
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Variação Genética , Família Multigênica , Software , Variação Genética/genética , Alinhamento de Sequência/métodosRESUMO
RESEARCH HIGHLIGHTS: Peptides + CpG-ODN reduced SH in caeca at the first week post-infection.Administered formulations did not reduce SH-faecal excretion.Levels of intestinal IgA were similar between all groups.CpG-ODN improved some parameters associated with chick intestinal health.
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Doenças das Aves Domésticas , Salmonelose Animal , Salmonella enterica , Animais , Sorogrupo , Salmonelose Animal/prevenção & controle , Salmonelose Animal/microbiologia , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/microbiologia , GalinhasRESUMO
This study aimed to investigate the antioxidant and anti-inflammatory properties of quercetin on the cellular components of the Enteric Nervous System in the ileum of rats with arthritis. Rats were distributed into five groups: control (C), arthritic (AIA), arthritic treated with ibuprofen (AI), arthritic treated with quercetin (AQ) and arthritic treated with both ibuprofen and quercetin (AIQ). The ileum was processed for immunohistochemical techniques for HuC/D, calcitonin gene-related peptide, and vasoactive intestinal polypeptide. Measurements in histological sections, chemiluminescence assays, and total antioxidant capacity were also performed. Rheumatoid arthritis resulted in a decrease in neuronal density, yet neuroplasticity mechanisms were evident through observed changes in varicosities size and neuronal area compared to the control group. Reduced paw edema and neuroprotective effects were predominantly noted in both plexuses, as evidenced by the increased density preservation of HuC/D-IR neurons in the AIQ group. The increase of lipoperoxidation levels and paw edema volume in the AQ group was observed compared to the arthritic, whereas the AIQ group mainly showed similar results to those observed in the control. The enteropathy associated with arthritis proved to be significant in the field of gastroenterology, and the combination of quercetin and ibuprofen demonstrated promising anti-inflammatory and neuroprotective effects.
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Anti-Inflamatórios , Antioxidantes , Ibuprofeno , Quercetina , Ratos Wistar , Animais , Quercetina/farmacologia , Quercetina/uso terapêutico , Ibuprofeno/farmacologia , Ibuprofeno/uso terapêutico , Ratos , Masculino , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Neurônios/efeitos dos fármacos , Neurônios/patologia , Artrite Experimental/tratamento farmacológico , Artrite Experimental/patologia , Sistema Nervoso Entérico/efeitos dos fármacos , Sistema Nervoso Entérico/patologia , Imuno-Histoquímica , Íleo/efeitos dos fármacos , Íleo/patologiaRESUMO
We report the sequencing and assembly of the PH8 strain of Leishmania amazonensis one of the etiological agents of leishmaniasis. After combining data from long Pacbio reads, short Illumina reads and synteny with the Leishmania mexicana genome, the sequence of 34 chromosomes with 8317 annotated genes was generated. Multigene families encoding three virulence factors, A2, amastins and the GP63 metalloproteases, were identified and compared to their annotation in other Leishmania species. As they have been recently recognized as virulence factors essential for disease establishment and progression of the infection, we also identified 14 genes encoding proteins involved in parasite iron and heme metabolism and compared to genes from other Trypanosomatids. To follow these studies with a genetic approach to address the role of virulence factors, we tested two CRISPR-Cas9 protocols to generate L. amazonensis knockout cell lines, using the Miltefosine transporter gene as a proof of concept.
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Leishmania mexicana , Leishmania , Leishmania mexicana/genética , Virulência/genética , Leishmania/genética , Genoma , Fatores de Virulência/metabolismoRESUMO
INTRODUCTION: Clostridioides difficile is the main cause of antibiotic-associated diarrhea in humans and is a major enteropathogen in several animal species. In newborn piglets, colonic lesions caused by C. difficile A and B toxins (TcdA and TcdB, respectively) cause diarrhea and significant production losses. OBJECTIVE: The present study aimed to develop two recombinant vaccines from immunogenic C-terminal fragments of TcdA and TcdB and evaluate the immune response in rabbits and in breeding sows. Two vaccines were produced: bivalent (rAB), consisting of recombinant fragments of TcdA and TcdB, and chimeric (rQAB), corresponding to the synthesis of the same fragments in a single protein. Groups of rabbits were inoculated with 10 or 50 µg of proteins adjuvanted with aluminum or 0.85 % sterile saline in a final volume of 1 mL/dose. Anti-TcdA and anti-TcdB IgG antibodies were detected in rabbits and sows immunized with both rAB and rQAB vaccines by ELISA. The vaccinated sows were inoculated intramuscularly with 20 µg/dose using a prime-boost approach. RESULTS: Different antibody titers (p ≤ 0.05) were observed among the vaccinated groups of sows (rAB and rQAB) and control. Additionally, newborn piglets from vaccinated sows were also positive for anti-TcdA and anti-TcdB IgGs, in contrast to control piglets (p ≤ 0.05). Immunization of sows with the rQAB vaccine conferred higher anti-TcdA and anti-TcdB responses in piglets, suggesting the superiority of this compound over rAB. CONCLUSION: The synthesized recombinant proteins were capable of inducing antibody titers against C. difficile toxins A and B in sows, and were passively transferred to piglets through colostrum.
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Sporotrichosis is a neglected fungal zoonosis with significant impacts on human and animal health. Accurate diagnosis, treatment, and understanding of the transmission dynamics of Sporothrix species are essential for mitigating the spread of sporotrichosis. This study aimed to identify the Sporothrix species involved in the ongoing outbreaks of animal sporotrichosis in the metropolitan region of Belo Horizonte, Minas Gerais, Brazil, and analyse the phylogenetic relationships between pathogenic species to investigate the outbreak origin. Additionally, to better understand the evolution of the disease, we conducted a retrospective survey of positive feline and canine cases from November 2017 to July 2021 with proven cultures for Sporothrix. A significant increase in animal cases over the last 4 years was observed, with cats being the most affected host. Sporothrix brasiliensis was the predominant agent in 100% of the clinical isolates (n = 180) molecularly identified. Phylogenetic and haplotype analysis points towards the cases isolated from Minas Gerais sharing the haplotype originating from a long-lasting outbreak of cat-transmitted sporotrichosis in Rio de Janeiro, however, with a secondary contribution from genotypes circulating in other outbreaks in Brazil. Thus, we present clear evidence of the circulation of different S. brasiliensis genotypes associated with animal sporotrichosis in the metropolitan region of Belo Horizonte. Genetic monitoring can contribute to understanding the causal agent for zoonotic sporotrichosis in epidemiological processes and help to implement disease prevention and control measures.
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Doenças do Gato , Sporothrix , Esporotricose , Humanos , Animais , Gatos , Cães , Esporotricose/tratamento farmacológico , Esporotricose/epidemiologia , Esporotricose/veterinária , Brasil/epidemiologia , Filogenia , Estudos Retrospectivos , Doenças do Gato/microbiologiaRESUMO
Homologous recombination (HR) has an intimate relationship with genome replication, both during repair of DNA lesions that might prevent DNA synthesis and in tackling stalls to the replication fork. Recent studies led us to ask if HR might have a more central role in replicating the genome of Leishmania, a eukaryotic parasite. Conflicting evidence has emerged regarding whether or not HR genes are essential, and genome-wide mapping has provided evidence for an unorthodox organisation of DNA replication initiation sites, termed origins. To answer this question, we have employed a combined CRISPR/Cas9 and DiCre approach to rapidly generate and assess the effect of conditional ablation of RAD51 and three RAD51-related proteins in Leishmania major. Using this approach, we demonstrate that loss of any of these HR factors is not immediately lethal but in each case growth slows with time and leads to DNA damage and accumulation of cells with aberrant DNA content. Despite these similarities, we show that only loss of RAD51 or RAD51-3 impairs DNA synthesis and causes elevated levels of genome-wide mutation. Furthermore, we show that these two HR factors act in distinct ways, since ablation of RAD51, but not RAD51-3, has a profound effect on DNA replication, causing loss of initiation at the major origins and increased DNA synthesis at subtelomeres. Our work clarifies questions regarding the importance of HR to survival of Leishmania and reveals an unanticipated, central role for RAD51 in the programme of genome replication in a microbial eukaryote.
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Recombinação Homóloga/genética , Leishmania major/genética , Leishmaniose Cutânea/genética , Rad51 Recombinase/genética , Sistemas CRISPR-Cas/genética , Dano ao DNA/genética , Reparo do DNA/genética , Replicação do DNA/genética , Técnicas de Inativação de Genes , Genoma/genética , Humanos , Leishmania major/patogenicidade , Leishmaniose Cutânea/parasitologiaRESUMO
Pencil drawing is one of the simplest and most cost-effective ways of fabricating miniaturized electrodes on a paper substrate. However, it is limited by the lack of reproducibility regarding the electrode drawing process. A 3D-printed pencil holder (3DPH) is proposed here for simple, reproducible, and low-cost hand-drawn fabrication of paper-based electrochemical devices. 3DPH was designed to keep pressure and angulation of the graphite mine constant on the paper substrate using a micromechanical pencil regardless of the user/operator. This approach significantly improved the reproducibility and cost of making reliable pencil-drawn electrodes. The results showed high reproducibility and accuracy of the 3DPH-assisted electrodes prepared by 4 different operators in terms of sheet resistance and electrochemical behavior. Cyclic voltammetric (CV) curves in the presence of [Fe(CN)6]3-/4- redox probe showed only 3.9% variation for the anodic peak currents of different electrodes prepared by different operators when compared with electrodes prepared without the 3D-printed support. SEM analyses revealed a more uniform graphite deposition/design of the electrodes prepared with 3DPH, which corroborates the results obtained by CV. As a proof of concept, 3DPH-assisted pencil-drawn graphite electrodes were employed for dopamine detection in synthetic saliva, showing a proportional increase in anodic peak current at 0.12 V vs. carbon pRE with increasing dopamine (DA) concentration, with a detection limit of 0.39µmol L-1. Moreover recovery was in the range 93-104% of DA (4-7% RSD) in synthetic saliva for three different concentrations, demonstrating the reliability of the approach. Finally, we believe this approach can make pencil-drawn technology more robust, accessible, reliable, and inexpensive for real on-site applications, especially in hard-to-reach locations or research centers with little investment.
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MOTIVATION: In silico identification of linear B-cell epitopes represents an important step in the development of diagnostic tests and vaccine candidates, by providing potential high-probability targets for experimental investigation. Current predictive tools were developed under a generalist approach, training models with heterogeneous datasets to develop predictors that can be deployed for a wide variety of pathogens. However, continuous advances in processing power and the increasing amount of epitope data for a broad range of pathogens indicate that training organism or taxon-specific models may become a feasible alternative, with unexplored potential gains in predictive performance. RESULTS: This article shows how organism-specific training of epitope prediction models can yield substantial performance gains across several quality metrics when compared to models trained with heterogeneous and hybrid data, and with a variety of widely used predictors from the literature. These results suggest a promising alternative for the development of custom-tailored predictive models with high predictive power, which can be easily implemented and deployed for the investigation of specific pathogens. AVAILABILITY AND IMPLEMENTATION: The data underlying this article, as well as the full reproducibility scripts, are available at https://github.com/fcampelo/OrgSpec-paper. The R package that implements the organism-specific pipeline functions is available at https://github.com/fcampelo/epitopes. SUPPLEMENTARY INFORMATION: Supplementary materials are available at Bioinformatics online.
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Mapeamento de Epitopos , Epitopos de Linfócito B , Aprendizado de Máquina , Análise de Sequência de Proteína , Humanos , Animais , Conjuntos de Dados como Assunto , Especificidade da Espécie , Análise de Sequência de Proteína/métodos , Mapeamento de Epitopos/métodosRESUMO
BACKGROUND: Brazil is among the countries in South America where the COVID-19 pandemic has hit the general population hardest. Self-testing for SARS-CoV-2 infection is one of the community-based strategies that could help asymptomatic individuals at-risk of COVID-19, as well as those living in areas that are difficult for health personnel to reach, to know their infectious status and contribute to impeding further transmission of the virus. METHODS: A population-based survey was conducted in November 2021, to assess the acceptability of rapid SARS-CoV-2 antigen self-testing among the population of São Paulo. Survey respondents were approached at more than 400 different street-points that were randomly selected using a five-stage randomization process. A 35-item structured questionnaire was used. Dependent variables for our analyses were the likelihood to use and willingness to pay for self-testing, and the likelihood of taking preventive measures to prevent onward transmission of SARS-CoV-2 following a reactive self-test result. Bivariate and multivariate regression analyses were performed. RESULTS: Overall, 417 respondents (44.12% female) participated; 19.66% had previously had COVID-19 disease. A minority (9.59%) felt at high-risk of COVID-19. The majority of both females and males (73.91% and 60.09%, respectively) were in favor of the idea of SARS-CoV-2 self-testing. Overall, if self-tests were available, almost half of the sample would be very likely (n = 54, 12.95%) or likely (n = 151, 36.21%) to use one if they felt they needed to. Upon receiving a positive self-test result, the majority of respondents would communicate it (88.49%), request facility-based post-test counseling (98.32%), self-isolate (97.60%), and warn their close contacts (96.64%). CONCLUSION: Rapid SARS-CoV-2 antigen self-testing could be an acceptable screening tool in São Paulo. The population would be empowered by having access to a technology that would allow them to test, even if asymptomatic, when traveling, or going to work or school. If there is a surge in the incidence of cases, self-testing could be a good approach for mass case detection by Brazil's already overstretched Unified Health System.
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COVID-19 , SARS-CoV-2 , Atitude , Brasil/epidemiologia , COVID-19/diagnóstico , COVID-19/epidemiologia , Feminino , Humanos , Masculino , Pandemias/prevenção & controle , Autoteste , Inquéritos e QuestionáriosRESUMO
OBJECTIVE: Heart rate variability (HRV), an index of the autonomic cardiac activity, is decreased in patients with epilepsy, and a low HRV is associated with a higher risk of sudden death. Generalized tonic-clonic seizures are one of the most consistent risk factors for SUDEP, but the influence (and relative risk) of each type of seizure on cardiac function is still unknown. Our objective was to assess the impact of the type of seizure (focal to bilateral tonic-clonic seizure - FBTCS - versus non-FBTCS) on periictal HRV, in a group of patients with refractory epilepsy and both types of seizures. METHODS: We performed a 48-hour Holter recording on 121 patients consecutively admitted to our Epilepsy Monitoring Unit. We only included patients with both FBTCS and non-FBTCS on the Holter recording and selected the first seizure of each type to analyze. To evaluate HRV parameters (AVNN, SDNN, RMSSD, pNN20, LF, HF, and LF/HF), we chose 5-min epochs pre- and postictally. RESULTS: We included 14 patients, with a median age of 36 (min-max, 16-55) years and 64% were female. Thirty-six percent had cardiovascular risk factors, but no previously known cardiac disease. In the preictal period, there were no statistically significant differences in HRV parameters, between FBTCS and non-FBTCS. In the postictal period, AVNN, RMSSD, pNN20, LF, and HF were significantly lower, and LF/HF and HR were significantly higher in FBTCS. From preictal to postictal periods, FBTCS elicited a statistically significant rise in HR and LF/HF, and a statistically significant fall in AVNN, RMSSD, pNN20, and HF. Non-FBTCS only caused statistically significant changes in HR (decrease) and AVNN (increase). SIGNIFICANCE/CONCLUSION: This work emphasizes the greater effect of FBTCS in autonomic cardiac function in patients with refractory epilepsy, compared to other types of seizures, with a significant reduction in vagal tonus, which may be associated with an increased risk of SUDEP.
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Epilepsia , Frequência Cardíaca , Convulsões , Adolescente , Adulto , Eletroencefalografia , Epilepsia/fisiopatologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Medição de Risco , Convulsões/classificação , Convulsões/fisiopatologia , Morte Súbita Inesperada na Epilepsia/epidemiologia , Adulto JovemRESUMO
BACKGROUND: The World Health Organization recommends the Maternal and Child Health Handbook (MCH-HB) to promote health service utilization from pregnancy to early childhood. Although many countries have adopted it as a national health policy, there is a paucity of research in MCH-HB's implementation. Thus, this study aimed to evaluate the MCH-HB's implementation status based on the RE-AIM framework (Reach, Effectiveness, Adoption, Implementation, Maintenance), and identify facilitators of, and barriers to its implementation in Angola to understand effective implementation strategies. METHODS: A cross-sectional survey was conducted targeting all health facilities which implemented MCH-HB, subsamples of health workers, and officers responsible for the MCH-HB at the municipality health office. Using the 14 indicators based on the RE-AIM framework, health facilities' overall implementation statuses were assessed. This categorized health facilities into optimal-implementation and suboptimal-implementation groups. To identify barriers to and facilitators of MCH-HB implementation, semi-structured interviews were conducted among health workers and municipality health officers responsible for MCH-HB. The data were analyzed via content analysis. RESULTS: A total of 88 health facilities and 216 health workers were surveyed to evaluate the implementation status, and 155 interviews were conducted among health workers to assess the barriers to and facilitators of the implementation. The overall implementation target was achieved in 50 health facilities (56.8%). The target was achieved by more health facilities in urban than rural areas (urban 68.4%, rural 53.6%) and by more health facilities of higher facility types (hospital 83.3%, health center 59.3%, health post 52.7%). Through the interview data's analysis, facilitators of and barriers to MCH-HB were comprehensively demonstrated. MCH-HB's content advantage was the most widely recognized facilitator and inadequate training for health workers was the most widely recognized barrier. CONCLUSIONS: Strengthening education for health workers, supervision by municipality health officers, and community sensitization were potential implementation strategies. These strategies must be intensified in rural and lower-level health facilities.
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Saúde da Criança , Promoção da Saúde , Angola , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Gravidez , População RuralRESUMO
Deep brain stimulation of the Anterior Nucleus of the Thalamus (ANT-DBS) is an effective therapy in epilepsy. Poorer surgical outcomes are related to deviations of the lead from the ANT-target. The target identification relies on the visualization of anatomical structures by medical imaging, which presents some disadvantages. This study aims to research whether ANT-LFPs recorded with the PerceptTM PC neurostimulator can be an asset in the identification of the DBS-target. For this purpose, 17 features were extracted from LFPs recorded from a single patient, who stayed at an Epilepsy Monitoring Unit for a 5-day period. Features were then integrated into two machine learning (ML)-based methodologies, according to different LFP bipolar montages: Pass1 (nonadjacent channels) and Pass2 (adjacent channels). We obtained an accuracy of 76.6% for the Pass1-classifier and 83.33% for the Pass2-classifier in distinguishing locations completely inserted in the target and completely outside. Then, both classifiers were used to predict the target percentage of all combinations, and we found that contacts 3 (left hemisphere) and 2 and 3 (right hemisphere) presented higher signatures of the ANT-target, which agreed with the medical images. This result opens a new window of opportunity for the use of LFPs in the guidance of DBS target identification.
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Núcleos Anteriores do Tálamo , Estimulação Encefálica Profunda , Epilepsia , Núcleos Anteriores do Tálamo/fisiologia , Estimulação Encefálica Profunda/métodos , Eletrodos , Epilepsia/terapia , HumanosRESUMO
BACKGROUND: Diabetes has been recognized as a risk factor contributing to the incidence and progression of Parkinson's disease (PD). Although several hypotheses suggest a number of different mechanisms underlying the aggravation of PD caused by diabetes, less attention has been paid to the fact that diabetes and PD share pathological microvascular alterations in the brain. The characteristics of the interaction of diabetes in combination with PD at the vascular interface are currently not known. METHODS: We combined a high-fat diet (HFD) model of diabetes mellitus type 2 (DMT2) with the 6-OHDA lesion model of PD in male mice. We analyzed the association between insulin resistance and the achieved degree of dopaminergic nigrostriatal pathology. We further assessed the impact of the interaction of the two pathologies on motor deficits using a battery of behavioral tests and on microglial activation using immunohistochemistry. Vascular pathology was investigated histologically by analyzing vessel density and branching points, pericyte density, blood-brain barrier leakage, and the interaction between microvessels and microglia in the striatum. RESULTS: Different degrees of PD lesion were obtained resulting in moderate and severe dopaminergic cell loss. Even though the HFD paradigm did not affect the degree of nigrostriatal lesion in the acute toxin-induced PD model used, we observed a partial aggravation of the motor performance of parkinsonian mice by the diet. Importantly, the combination of a moderate PD pathology and HFD resulted in a significant pericyte depletion, an absence of an angiogenic response, and a significant reduction in microglia/vascular interaction pointing to an aggravation of vascular pathology. CONCLUSION: This study provides the first evidence for an interaction of DMT2 and PD at the brain microvasculature involving changes in the interaction of microglia with microvessels. These pathological changes may contribute to the pathological mechanisms underlying the accelerated progression of PD when associated with diabetes.
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Diabetes Mellitus Tipo 2/patologia , Dieta Hiperlipídica , Neurônios Dopaminérgicos/metabolismo , Microglia/patologia , Doença de Parkinson Secundária/patologia , Pericitos/patologia , Anfetamina/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Corpo Estriado/patologia , Diabetes Mellitus Tipo 2/metabolismo , Modelos Animais de Doenças , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/patologia , Resistência à Insulina/fisiologia , Masculino , Camundongos , Microglia/efeitos dos fármacos , Microglia/metabolismo , Oxidopamina , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/metabolismo , Pericitos/efeitos dos fármacos , Pericitos/metabolismoRESUMO
PURPOSE: The aim of this study was to compare all retinal layers' thickness in full-term and preterm children without retinopathy of prematurity (ROP). METHODS: Cross-sectional study including two groups of patients: group 1 children with history of preterm gestation without ROP (gestational age < 37 weeks) and group 2 healthy children with history of full-term gestation. All subjects underwent an ophthalmic examination including spectral domain-optical coherence tomography. After automatic retinal segmentation, each retinal layer thickness (eight separate layers and overall thickness) was calculated in all nine Early Treatment Diabetic Retinopathy Study areas. Demographic, systemic, gestational, and birth data were collected. Generalized additive regression models were used to analyze the data. RESULTS: Fifty-one children (51 eyes) were recruited, 19 full-term and 32 preterm children, mean age at ophthalmic examination of 10.58 (4.21) and 14.13 (3.16), respectively. In multivariable analysis, the preterm group's retinal thickness was significantly decreased in total retina nasal outer sector, ganglion cell layer (GCL), and inner plexiform layer (IPL), specifically GCL temporal outer (p = 0.010), GCL superior outer (p = 0.009), IPL temporal outer (p = 0.022), and IPL superior outer (p = 0.004), when compared with full-term group. From the variables compared only with birth head circumference that influenced the models, a non-linear association was identified and consequently modeled with splines through a generalized additive model. CONCLUSION: This study suggests that preterm children without ROP have structural retinal alterations, mostly in GCL and IPL in outer areas of the macula. Therefore, it is crucial to question gestational history since these retinal changes may be found later in life leading to useless investigation.
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Macula Lutea , Retinopatia da Prematuridade , Criança , Estudos Transversais , Humanos , Recém-Nascido , Retina/diagnóstico por imagem , Retinopatia da Prematuridade/diagnóstico , Tomografia de Coerência Óptica , Acuidade VisualRESUMO
Inducing and controlling temperature gradients in illuminated subwavelength plasmonic structures is a challenging task. Here, we present a strategy to remotely induce and tune temperature gradients in a subwavelength metallic nanocone by adjusting the angle of incidence of linearly polarized continuous-wave illumination. We demonstrate, through rigorous three-dimensional numerical simulations, that properly tilting the incident illumination angle can increase or decrease the photoinduced temperature gradients within the nanostructure. We analyze the apex-base photoinduced temperature gradient for different illumination directions, resembling typical illumination schemes utilized in surface or tip-enhanced Raman spectroscopy.
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Paracentral acute middle maculopathy (PAMM) is a recently identified spectral-domain optical coherence tomography (SD-OCT) finding characterized by a hyper-reflective band spanning the inner nuclear layer (INL), which typically evolves to INL atrophy in later stages. Typical clinical features include the sudden onset of one or multiple paracentral scotomas, normal or mild reduction in visual acuity, and a normal fundus appearance or a fundus with a deep grayish lesion. Although its pathophysiology is not yet fully understood, ischemia at the level of the intermediate and deep capillary plexa has been demonstrated to play a major role. Since its first description, an increasing number of publications on PAMM have been published in ophthalmology scientific journals. The purpose of this study is to provide a review of the current literature on PAMM.