Síndrome dos ovários policísticos (SOP): fatores de risco associados e as observações na pandemia da Covid-19 / Polycystic ovary syndrome (PCOS): associated risk factors and observations in the Covid-19 pandemic

A Síndrome dos Ovários Policísticos (SOP) é um distúrbio endócrino heterogêneo que afeta mulheres em idade reprodutiva em todo o mundo. Estima-se que aproximadamente 1 em cada 10 mulheres enfrenta SOP e padece com suas complicações. Esse distúrbio endócrino, envolve em sua etiologia mecanismos de desenvolvimento diversos, permeando fatores risco genéticos e epigenéticos, o que influencia no seu diagnóstico e prognóstico. Entretanto, no que tange a sua fisiopatologia, essa possui características complexas que ainda não são totalmente compreendidas. Quanto às manifestações clínicas, estas estão relacionadas a irregularidade dos ciclos menstruais, hiperandrogenismo e outros acometimentos metabólicos característicos da síndrome. Dentro desse contexto, para além dos múltiplos fatores de risco já conhecidos, observou-se, no âmbito da pandemia do Coronavírus, um paralelo entre a presença da SOP e uma maior susceptibilidade de infecção pelo vírus da Covid-19, levando a uma maior atenção para essas pacientes. No que tange ao diagnóstico, este é considerado essencialmente um diagnóstico de exclusão, sendo utilizado para isso o critério de Rotterdam através de dois dos seguintes achados: presença de oligo-amenorreia, morfologia ovariana e hiperandrogenismo clínico e/ou laboratorial, não havendo exames específicos para sua detecção. Por fim, no que concerne ao tratamento, este deve ser realizado de acordo com as manifestações de cada paciente, associando mudanças no estilo de vida e intervenções farmacológicas. Diante disso, diversos dilemas podem ser levantados no contexto da SOP, ressaltando assim, a importância da delimitação dos fatores de risco associados, com o intuito de fornecer um tratamento rápido e adequado para cada paciente

A social and ecological assessment of tropical land uses at multiple scales: the Sustainable Amazon Network

Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazonia Sustentavel, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far.Keywords: Social–ecological systems, Tropical forests, Land use, Interdisciplinary research, Sustainability, Trade-off

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Reparo de DNA em dois patógenos humanos: caracterização do gene IMP4 de Schistosoma mansini e estudos acerca do MMR, Sistema GO e taxa de mutação em Trypanosoma cruzi

Exportado OPUSMade available in DSpace on 2019-08-13T12:41:16Z (GMT). No. of bitstreams: 1 tese_carolina_furtado_torres_da_silva.pdf: 7053948 bytes, checksum: fd933a4bfda9acf1498df42a00d96ba8 (MD5) Previous issue date: 30O conteúdo genético de um organismo está continuamente exposto a agentes que danificam a molécula de DNA, causando mutações ou comprometendo suas funções. Complexos mecanismos de reparo ou tolerância a danos no DNA ajudam a manter baixas as taxas de mutação em uma célula e a garantir a integridade do seu genoma. Neste trabalho, estudamos o reparo de DNA em dois parasitos humanos, Schistosoma mansoni e Trypanosoma cruzi, causadores da esquistossomose e da Doença de Chagas no Brasil. Esses parasitas são expostos a diferentes agentes genotóxicos ao longo do ciclo de vida e necessitam, portanto, apresentar diversos mecanismos de adaptação. Através da estratégia de complementação funcional heteróloga, isolamos um cDNA de S. mansoni capaz de complementar bactérias deficientes na via de reparo por excisão de bases (BER). O sequenciamento do cDNA indicou homologia ao gene ScIMP4 de Saccharomyces cerevisiae, que está envolvido no metabolismo de RNA. Construímos uma linhagem mutante de S. cerevisiae, que codifica a proteína IMP4 truncada e verificamos que esta apresenta sensibilidade acentuada a MMS. Observamos ainda que o gene IMP4 de S. mansoni foi capaz de complementar parcialmente a levedura mutante, indicando homologia funcional entre os genes IMP4 do verme e da levedura. Na segunda etapa deste trabalho, estudamos mecanismos de reparo de DNA possivelmente associados à geração de variabilidade genética em T. cruzi. Nosso grupo demonstrou previamente a existência de três isoformas (A, B e C) da proteína TcMSH2 em T. cruzi. Esta proteína é o principal componente da via de reparo de erros de pareamento (MMR) em eucariotos. Através de ensaios in vivo com cisplatina, MNNG e H2O2, na presença de cloreto de cádmio (em concentrações que inibem especificamente o MMR), obtivemos novos indícios de que as cepas que codificam a isoforma A de TcMSH2 apresentam MMR mais eficiente, quando comparadas a cepas que codificam a isoforma C desta proteína, e isto pode estar relacionado com a maior variabilidade genética vista nas últimas. Para estudar mecanismos de resposta a danos oxidativos em T. cruzi, caracterizamos o possível ortólogo de OGG1 no parasito. Vimos que a expressão do alelo TcOgg1A é tóxica em bactérias e que a superexpressão deste no clone CL Brener aumenta sua sensibilidade ao tratamento com H2O2. Ainda, realizamos uma busca por homólogos funcionais de MutT em T. cruzi. Nossos resultados indicam que os alelos Ndx1 e Ndx4, que apresentam o domínio Nudix, não complementam bactérias deficientes em MutT. Também observamos que a superexpressão de EcMutT em T. cruzi aumenta a sobrevivência dos parasitos em resposta ao tratamento com H2O2 e reduz os níveis de 8-oxoG após estresse oxidativo. Finalmente, desenvolvemos um sistema repórter capaz de avaliar a taxa de mutação em T. cruzi. O ensaio, realizado em meio semi-sólido, baseia-se na seleção de mutantes resistentes a neomicina, que revertem uma mutação inserida no gene neo introduzido no genoma do parasito. Os resultados obtidos em um ensaio preliminar indicam a viabilidade da metodologia, através da qual seremos capazes de determinar a taxa de mutação em diferentes cepas de T. cruzi, assim como avaliar o efeito de diferentes agentes mutagênicos no parasita.Cells have evolved a complex set of mechanisms to appropriately respond to genotoxic damage, ensuring genomic stability. Such responses retain mutation rates in an acceptable level, through a fine-tuning balance between genome maintenance and generation of genetic variability. In this work, we studied some features of the DNA repair machinery of Schistosoma mansoni and Trypanosoma cruzi, the causative agents of schistosomiasis and Chagas disease in Brazil. Both parasites need to adapt to distinct environments, and are consequently exposed to various DNA damaging agents. Using a functional heterologue complementation strategy, we have isolated a S. mansoni cDNA that complements Escherichia coli mutants defective in the DNA base excision repair (BER) pathway. This cDNA has sequence homology to a gene involved in the RNA metabolism pathway, the ScIMP4 gene of Saccharomyces cerevisiae. To establish whether the S. mansoni cDNA could complement yeast mutants ScIMP4-defective, we constructed a yeast haploid strain containing a truncated Imp4p gene which shows MMS sensitivity. The functional homology between the ScIMP4 gene and the cDNA from S. mansoni was verified by partial complementation of the mutant yeast with the worms gene. As a second goal, we studied T. cruzi DNA repair mechanisms possibly involved in the generation of genetic variability in this protozoan parasite. We have previously demonstrated that polymorphisms in the TcMSH2 locus, which encodes a key component of the mismatch repair (MMR), result in three different protein isoforms present in the T. cruzi population. Using cisplatin, MNNG and H2O2 in vivo assays performed with cadmium, which in sub lethal concentrations inhibits specifically the MMR, we provided evidences that TcMSH2A-expressing parasites have increased MMR activity when compared to parasite strains expressing TcMSH2C isoforms. To better understand the mechanisms involved in the oxidative DNA damage response in T. cruzi we characterized the putative OGG1 ortologue in the parasite and showed that (i) TcOgg1A expression is toxic in bacteria and (ii) stably TcOgg1A transfected parasites have increased H2O2 sensitivity. Additionally, a search for candidates for a functional homologue of E. coli MutT in T. cruzi using the Nudix Box was attempted. We`ve found that expression of Ndx1 or Ndx4 was unable to suppress the high spontaneous mutagenesis of E. coli mutT-deficient strain and that EcMutT overexpressing parasites showed increased survival and decreased 8oxoG levels after H2O2 treatment. Finally, we developed a methodology to determine the mutation rate in T. cruzi. The assay is performed in semisolid medium plates and is based on the selection of clones that spontaneously reverts the neomycin-sensitive phenotype caused by a single base substitution in the neomycin resistance gene (neo) inserted into the parasite genome. Our preliminary results indicate that this experimental approach is functional since (i) clones that grew in neomycin containing plates have the mutation repaired as shown by DNA sequence, (ii) a proportionally higher number of clones able to grow in the presence of neomycin was observed after long-time culture in liquid medium and in cultures that were treated with a mutagenic agent. This methodology is now in place in our laboratory to be used to determine the mutation rate in distinct T. cruzi strains, as well as analyzing the effect of different mutagens in this parasite

Assessment of genetic mutation frequency induced by oxidative stress in Trypanosoma cruzi

Abstract Trypanosoma cruzi is the etiological agent of Chagas disease, a public health challenge due to its morbidity and mortality rates, which affects around 6-7 million people worldwide. Symptoms, response to chemotherapy, and the course of Chagas disease are greatly influenced by T. cruzi‘s intra-specific variability. Thus, DNA mutations in this parasite possibly play a key role in the wide range of clinical manifestations and in drug sensitivity. Indeed, the environmental conditions of oxidative stress faced by T. cruzi during its life cycle can generate genetic mutations. However, the lack of an established experimental design to assess mutation rates in T. cruzi precludes the study of conditions and mechanisms that potentially produce genomic variability in this parasite. We developed an assay that employs a reporter gene that, once mutated in specific positions, convert G418-sensitive into G418-insenstitive T. cruzi. We were able to determine the frequency of DNA mutations in T. cruzi exposed and non-exposed to oxidative insults assessing the number of colony-forming units in solid selective media after plating a defined number of cells. We verified that T. cruzi‘s spontaneous mutation frequency was comparable to those found in other eukaryotes, and that exposure to hydrogen peroxide promoted a two-fold increase in T. cruzi‘s mutation frequency. We hypothesize that genetic mutations in T. cruzi can arise from oxidative insults faced by this parasite during its life cycle

Assessment of genetic mutation frequency induced by oxidative stress in Trypanosoma cruzi

<div><p>Abstract Trypanosoma cruzi is the etiological agent of Chagas disease, a public health challenge due to its morbidity and mortality rates, which affects around 6-7 million people worldwide. Symptoms, response to chemotherapy, and the course of Chagas disease are greatly influenced by T. cruzi‘s intra-specific variability. Thus, DNA mutations in this parasite possibly play a key role in the wide range of clinical manifestations and in drug sensitivity. Indeed, the environmental conditions of oxidative stress faced by T. cruzi during its life cycle can generate genetic mutations. However, the lack of an established experimental design to assess mutation rates in T. cruzi precludes the study of conditions and mechanisms that potentially produce genomic variability in this parasite. We developed an assay that employs a reporter gene that, once mutated in specific positions, convert G418-sensitive into G418-insenstitive T. cruzi. We were able to determine the frequency of DNA mutations in T. cruzi exposed and non-exposed to oxidative insults assessing the number of colony-forming units in solid selective media after plating a defined number of cells. We verified that T. cruzi‘s spontaneous mutation frequency was comparable to those found in other eukaryotes, and that exposure to hydrogen peroxide promoted a two-fold increase in T. cruzi‘s mutation frequency. We hypothesize that genetic mutations in T. cruzi can arise from oxidative insults faced by this parasite during its life cycle.</p></div

A social and ecological assessment of tropical land uses at multiple scales:the Sustainable Amazon Network

Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazonia Sustentavel, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far

NEOTROPICAL FRESHWATER FISHES: A dataset of occurrence and abundance of freshwater fishes in the Neotropics

The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications