RESUMO
The production of fossil fuels, including oil, gas, and coal, retains a dominant share in US energy production and serves as a major anthropogenic source of methane, a greenhouse gas with a high warming potential. In addition to directly emitting methane into the air, fossil fuel production can release methane into groundwater, and that methane may eventually reach the atmosphere. In this study, we collected 311 water samples from an unconventional oil and gas (UOG) production region in Pennsylvania and an oil and gas (O&G) and coal production region across Ohio and West Virginia. Methane concentration was negatively correlated to distance to the nearest O&G well in the second region, but such a correlation was shown to be driven by topography as a confounding variable. Furthermore, sulfate concentration was negatively correlated with methane concentration and with distance to coal mining in the second region, and these correlations were robust even when considering topography. We hypothesized that coal mining enriched sulfate in groundwater, which in turn inhibited methanogenesis and enhanced microbial methane oxidation. Thus, this study highlights the complex interplay of multiple factors in shaping groundwater methane concentrations, including biogeochemical conversion, topography, and conventional fossil extraction.
Assuntos
Combustíveis Fósseis , Água Subterrânea , Campos de Petróleo e Gás , Metano , Região dos Apalaches , Carvão Mineral , SulfatosRESUMO
BACKGROUND: Chemicals used or emitted by unconventional oil and gas development (UOGD) include reproductive/developmental toxicants. Associations between UOGD and certain birth defects were reported in a few studies, with none conducted in Ohio, which experienced a thirty-fold increase in natural gas production between 2010 and 2020. METHODS: We conducted a registry-based cohort study of 965,236 live births in Ohio from 2010 to 2017. Birth defects were identified in 4653 individuals using state birth records and a state surveillance system. We assigned UOGD exposure based on maternal residential proximity at birth to active UOG wells and a metric specific to the drinking-water exposure pathway that identified UOG wells hydrologically connected to a residence ("upgradient UOG wells"). We estimated odds ratios (ORs) and 95% confidence intervals (CIs) for all structural birth defects combined and specific birth defect types using binary exposure metrics (presence/absence of any UOG well and presence/absence of an upgradient UOG well within 10 km), adjusting for confounders. Additionally, we conducted analyses stratified by urbanicity, infant sex, and social vulnerability. RESULTS: The odds of any structural defect were 1.13 times higher in children born to mothers living within 10 km of UOGD than those born to unexposed mothers (95%CI: 0.98-1.30). Odds were elevated for neural tube defects (OR: 1.57, 95%CI: 1.12-2.19), limb reduction defects (OR: 1.99, 95%CI: 1.18-3.35), and spina bifida (OR 1.93; 95%CI 1.25-2.98). Hypospadias (males only) was inversely related to UOGD exposure (OR: 0.62, 95%CI: 0.43-0.91). Odds of any structural defect were greater in magnitude but less precise in analyses using the hydrological-specific metric (OR: 1.30; 95%CI: 0.85-1.90), in areas with high social vulnerability (OR: 1.27, 95%CI: 0.99-1.60), and among female offspring (OR: 1.28, 95%CI: 1.06-1.53). CONCLUSIONS: Our results suggest a positive association between UOGD and certain birth defects, and findings for neural tube defects corroborate results from prior studies.
Assuntos
Gás Natural , Defeitos do Tubo Neural , Masculino , Gravidez , Recém-Nascido , Criança , Humanos , Feminino , Ohio/epidemiologia , Estudos de Coortes , PartoRESUMO
Concerns over unconventional oil and gas (UOG) development persist, especially in rural communities that rely on shallow groundwater for drinking and other domestic purposes. Given the continued expansion of the industry, regional (vs local scale) models are needed to characterize groundwater contamination risks faced by the increasing proportion of the population residing in areas that accommodate UOG extraction. In this paper, we evaluate groundwater vulnerability to contamination from surface spills and shallow subsurface leakage of UOG wells within a 104,000 km2 region in the Appalachian Basin, northeastern USA. We test a computationally efficient ensemble approach for simulating groundwater flow and contaminant transport processes to quantify vulnerability with high resolution. We also examine metamodels, or machine learning models trained to emulate physically based models, and investigate their spatial transferability. We identify predictors describing proximity to UOG, hydrology, and topography that are important for metamodels to make accurate vulnerability predictions outside their training regions. Using our approach, we estimate that 21,000-30,000 individuals in our study area are dependent on domestic water wells that are vulnerable to contamination from UOG activities. Our novel modeling framework could be used to guide groundwater monitoring, provide information for public health studies, and assess environmental justice issues.
Assuntos
Água Subterrânea , Poluentes Químicos da Água , Monitoramento Ambiental , Humanos , Hidrocarbonetos , Campos de Petróleo e Gás , Poluentes Químicos da Água/análise , Poços de ÁguaRESUMO
Health studies report associations between metrics of residential proximity to unconventional oil and gas (UOG) development and adverse health endpoints. We investigated whether exposure through household groundwater is captured by existing metrics and a newly developed metric incorporating groundwater flow paths. We compared metrics with detection frequencies/concentrations of 64 organic and inorganic UOG-related chemicals/groups in residential groundwater from 255 homes (Pennsylvania n = 94 and Ohio n = 161). Twenty-seven chemicals were detected in ≥20% of water samples at concentrations generally below U.S. Environmental Protection Agency standards. In Pennsylvania, two organic chemicals/groups had reduced odds of detection with increasing distance to the nearest well: 1,2-dichloroethene and benzene (Odds Ratio [OR]: 0.46, 95% confidence interval [CI]: 0.23-0.93) and m- and p-xylene (OR: 0.28, 95% CI: 0.10-0.80); results were consistent across metrics. In Ohio, the odds of detecting toluene increased with increasing distance to the nearest well (OR: 1.48, 95% CI: 1.12-1.95), also consistent across metrics. Correlations between inorganic chemicals and metrics were limited (all |ρ| ≤ 0.28). Limited associations between metrics and chemicals may indicate that UOG-related water contamination occurs rarely/episodically, more complex metrics may be needed to capture drinking water exposure, and/or spatial metrics in health studies may better reflect exposure to other stressors.
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Água Potável , Água Subterrânea , Poluentes Químicos da Água , Região dos Apalaches , Monitoramento Ambiental/métodos , Campos de Petróleo e Gás , Poluentes Químicos da Água/análiseRESUMO
BACKGROUND: Good governance and regulatory supervision are required to conduct research in an international public health emergency context and to ensure compliance with ethical standards. The "Strengthening research ethics governance and regulatory oversight in Central America and the Dominican Republic in response to the COVID-19 pandemic" study is a regional effort in which research ethics stakeholders participated in addressing research ethics governance and preparedness response challenges to the COVID-19 pandemic in Central America and the Dominican Republic. METHODS: A qualitative action research study was conducted following a participatory approach. Research ethics stakeholders in Central America and the Dominican Republic were mapped; a regional webinar and three virtual workshops were conducted discussing research ethics governance, ethics review and collaborative research practice during the pandemic. A roundtable session presented results and obtained feedback on a draft of a policy to strengthen regional research ethics governance. RESULTS: Countries across Central America and the Dominican Republic are at different stages in their development of research ethics systems. Countries with more established systems before COVID-19 were better organized and prepared to respond. This finding argues against improvisation and supports further work on strengthening governance of research ethics systems. Community engagement in research ethics public policy-making is practically absent in the region. Research and research ethics collaboration schemes are lacking amongst the countries; however, there are incipient initiatives in the region, such as the Central America and Caribbean Network of Research Ethics Committees. A policy brief with recommendations on how to advance towards strengthening the governance of research ethics systems was prepared and submitted to the Central American Integration System for analysis and possible approval. CONCLUSION: National research ethics systems in Central America and the Dominican Republic were unprepared to respond to the COVID-19 pandemic with respect to research oversight and effective collaboration. In most cases, national research ethics systems were found to be weak, and regional research collaboration was practically absent. To promote collaboration, a joint strategy needs to be developed with a regional vision towards sharing knowledge and best practices.
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COVID-19 , Pandemias , Humanos , República Dominicana , América Central , Ética em PesquisaRESUMO
Conflicting evidence exists as to whether or not unconventional oil and gas (UOG) development has enhanced methane transport into groundwater aquifers over the past 15 years. In this study, recent groundwater samples were collected from 90 domestic wells and 4 springs in Northeastern Pennsylvania located above the Marcellus Shale after more than a decade of UOG development. No statistically significant correlations were observed between the groundwater methane level and various UOG geospatial metrics, including proximity to UOG wells and well violations, as well as the number of UOG wells and violations within particular radii. The δ13C and methane-to-higher chain hydrocarbon signatures suggested that the elevated methane levels were not attributable to UOG development nor could they be explained by using simple biogenic-thermogenic end-member mixing models. Instead, groundwater methane levels were significantly correlated with geochemical water type and topographical location. Comparing a subset of contemporary methane measurements to their co-located pre-drilling records (n = 64 at 49 distinct locations) did not indicate systematic increases in methane concentration but did reveal several cases of elevated concentration (n = 12) across a spectrum of topographies. Multiple lines of evidence suggested that the high-concentration groundwater methane could have originated from shallow thermogenic methane that migrated upward into groundwater aquifers with Appalachian Basin brine.
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Água Subterrânea , Poluentes Químicos da Água , Monitoramento Ambiental , Metano/análise , Gás Natural , Campos de Petróleo e Gás , Pennsylvania , Poluentes Químicos da Água/análiseRESUMO
Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal (non-epithelial) neoplasms of the human gastrointestinal (GI) tract. They are thought to derive from interstitial cells of Cajal (ICCs) or an ICC progenitor based on immunophenotypical and ultrastructural similarities. Because ICCs show primary cilium, our hypothesis is based on the possibility that some of these neoplastic cells could also present it. To determine this, an exhaustive ultrastructural study has been developed on four gastric GISTs. Previous studies had demonstrated considerable variability in tumour cells with two dominating phenotypes, spindly and epithelioid. In addition to these two types, we have found another cell type reminiscent of adult ICCs with a voluminous nucleus surrounded by narrow perinuclear cytoplasm with long slender cytoplasmic processes. We have also noted the presence of small undifferentiated cells. In this study, we report for the first time the presence of primary cilia (PCs) in spindle and epithelioid tumour cells, an ultrastructural feature we consider of special interest that has hitherto been ignored in the literature dealing with the ultrastructure of GISTs. We also point out the frequent occurrence of multivesicular bodies (MVBs). The ultrastructural findings described in gastric GISTs in this study appear to be relevant considering the critical roles played by PCs and MVBs recently demonstrated in tumourigenic processes.
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Cílios/patologia , Neoplasias Gastrointestinais/patologia , Tumores do Estroma Gastrointestinal/ultraestrutura , Actinas/metabolismo , Antígenos CD34/metabolismo , Biomarcadores Tumorais/metabolismo , Citoplasma/metabolismo , Desmina/metabolismo , Neoplasias Gastrointestinais/diagnóstico por imagem , Tumores do Estroma Gastrointestinal/patologia , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Imunofenotipagem , Células Intersticiais de Cajal/metabolismo , Microscopia Eletrônica de Transmissão , Fenótipo , Proteínas Proto-Oncogênicas c-kit/metabolismo , Proteínas S100/metabolismo , UltrassonografiaRESUMO
The primary cilium is a non-motile cilium whose structure is 9+0. It is involved in co-ordinating cellular signal transduction pathways, developmental processes and tissue homeostasis. Defects in the structure or function of the primary cilium underlie numerous human diseases, collectively termed ciliopathies. The presence of single cilia in the central nervous system (CNS) is well documented, including some choroid plexus cells, neural stem cells, neurons and astrocytes, but the presence of primary cilia in differentiated neurons of the enteric nervous system (ENS) has not yet been described in mammals to the best of our knowledge. The enteric nervous system closely resembles the central nervous system. In fact, the ultrastructure of the ENS is more similar to the CNS ultrastructure than to the rest of the peripheral nervous system. This research work describes for the first time the ultrastructural characteristics of the single cilium in neurons of rat duodenum myenteric plexus, and reviews the cilium function in the CNS to propose the possible role of cilia in the ENS cells.
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Duodeno/inervação , Sistema Nervoso Entérico/ultraestrutura , Neurônios/ultraestrutura , Animais , Cílios/fisiologia , Cílios/ultraestrutura , Duodeno/citologia , Sistema Nervoso Entérico/fisiologia , Humanos , Microscopia Eletrônica de Transmissão , Microtomia , Plexo Mientérico/citologia , Plexo Mientérico/fisiologia , Neurônios/fisiologia , Ratos , Ratos WistarRESUMO
Unconventional oil and gas (UOG) development, made possible by horizontal drilling and high-volume hydraulic fracturing, has been fraught with controversy since the industry's rapid expansion in the early 2000's. Concerns about environmental contamination and public health risks persist in many rural communities that depend on groundwater resources for drinking and other daily needs. Spatial disparities in UOG risks can pose distributive environmental injustice if such risks are disproportionately borne by marginalized communities. In this paper, we analyzed groundwater vulnerability to contamination from UOG as a physically based measure of risk in conjunction with census tract level sociodemographic characteristics describing social vulnerability in the northern Appalachian Basin. We found significant associations between elevated groundwater vulnerability and lower population density, consistent with UOG development occurring in less densely populated rural areas. We also found associations between elevated groundwater vulnerability and lower income, higher proportions of elderly populations, and higher proportion of mobile homes, suggesting a disproportionate risk burden on these socially vulnerable groups. We did not find a statistically significant association between elevated groundwater vulnerability and populations of racial/ethnic minorities in our study region. Household surveys provided empirical support for a relationship between sociodemographic characteristics and capacity to assess and mitigate exposures to potentially contaminated water. Further research is needed to probe if the observed disparities translate to differences in chemical exposure and adverse health outcomes.
RESUMO
Gasdermin (GSDM)-mediated pyroptosis is functionally involved in multiple diseases, but Gasdermin-B (GSDMB) exhibit cell death-dependent and independent activities in several pathologies including cancer. When the GSDMB pore-forming N-terminal domain is released by Granzyme-A cleavage, it provokes cancer cell death, but uncleaved GSDMB promotes multiple pro-tumoral effects (invasion, metastasis, and drug resistance). To uncover the mechanisms of GSDMB pyroptosis, here we determined the GSDMB regions essential for cell death and described for the first time a differential role of the four translated GSDMB isoforms (GSDMB1-4, that differ in the alternative usage of exons 6-7) in this process. Accordingly, we here prove that exon 6 translation is essential for GSDMB mediated pyroptosis, and therefore, GSDMB isoforms lacking this exon (GSDMB1-2) cannot provoke cancer cell death. Consistently, in breast carcinomas the expression of GSDMB2, and not exon 6-containing variants (GSDMB3-4), associates with unfavourable clinical-pathological parameters. Mechanistically, we show that GSDMB N-terminal constructs containing exon-6 provoke cell membrane lysis and a concomitant mitochondrial damage. Moreover, we have identified specific residues within exon 6 and other regions of the N-terminal domain that are important for GSDMB-triggered cell death as well as for mitochondrial impairment. Additionally, we demonstrated that GSDMB cleavage by specific proteases (Granzyme-A, Neutrophil Elastase and caspases) have different effects on pyroptosis regulation. Thus, immunocyte-derived Granzyme-A can cleave all GSDMB isoforms, but in only those containing exon 6, this processing results in pyroptosis induction. By contrast, the cleavage of GSDMB isoforms by Neutrophil Elastase or caspases produces short N-terminal fragments with no cytotoxic activity, thus suggesting that these proteases act as inhibitory mechanisms of pyroptosis. Summarizing, our results have important implications for understanding the complex roles of GSDMB isoforms in cancer or other pathologies and for the future design of GSDMB-targeted therapies.
Assuntos
Neoplasias da Mama , Piroptose , Humanos , Feminino , Granzimas/genética , Granzimas/metabolismo , Peptídeo Hidrolases/metabolismo , Elastase de Leucócito/metabolismo , Gasderminas , Proteínas de Neoplasias/metabolismo , Caspases/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Neoplasias da Mama/genética , Proteínas Citotóxicas Formadoras de Poros/metabolismoRESUMO
BACKGROUND: Unconventional oil and gas development (UOGD) releases chemicals that have been linked to cancer and childhood leukemia. Studies of UOGD exposure and childhood leukemia are extremely limited. OBJECTIVE: The objective of this study was to evaluate potential associations between residential proximity to UOGD and risk of acute lymphoblastic leukemia (ALL), the most common form of childhood leukemia, in a large regional sample using UOGD-specific metrics, including a novel metric to represent the water pathway. METHODS: We conducted a registry-based case-control study of 405 children ages 2-7 y diagnosed with ALL in Pennsylvania between 2009-2017, and 2,080 controls matched on birth year. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between residential proximity to UOGD (including a new water pathway-specific proximity metric) and ALL in two exposure windows: a primary window (3 months preconception to 1 y prior to diagnosis/reference date) and a perinatal window (preconception to birth). RESULTS: Children with at least one UOG well within 2km of their birth residence during the primary window had 1.98 times the odds of developing ALL in comparison with those with no UOG wells [95% confidence interval (CI): 1.06, 3.69]. Children with at least one vs. no UOG wells within 2km during the perinatal window had 2.80 times the odds of developing ALL (95% CI: 1.11, 7.05). These relationships were slightly attenuated after adjusting for maternal race and socio-economic status [odds ratio (OR) =1.74 (95% CI: 0.93, 3.27) and OR=2.35 (95% CI: 0.93, 5.95)], respectively). The ORs produced by models using the water pathway-specific metric were similar in magnitude to the aggregate metric. DISCUSSION: Our study including a novel UOGD metric found UOGD to be a risk factor for childhood ALL. This work adds to mounting evidence of UOGD's impacts on children's health, providing additional support for limiting UOGD near residences. https://doi.org/10.1289/EHP11092.
Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Razão de Chances , Pennsylvania/epidemiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Gravidez , Fatores de Risco , ÁguaRESUMO
Horizontal drilling with hydraulic fracturing (HDHF) relies on the use of anthropogenic organic chemicals in proximity to residential areas, raising concern for groundwater contamination. Here, we extensively characterized organic contaminants in 94 domestic groundwater sites in Northeastern Pennsylvania after ten years of activity in the region. All analyzed volatile and semi-volatile compounds were below recommended United States Environmental Protection Agency maximum contaminant levels, and integrated concentrations across two volatility ranges, gasoline range organic compounds (GRO) and diesel range organic compounds (DRO), were low (0.13 ± 0.06 to 2.2 ± 0.7 ppb and 5.2-101.6 ppb, respectively). Following dozens of correlation analyses with distance-to-well metrics and inter-chemical indicator correlations, no statistically significant correlations were found except: (1) GRO levels were higher within 2 km of violations and (2) correlation between DRO and a few inorganic species (e.g., Ba and Sr) and methane. The correlation of DRO with inorganic species suggests a potential high salinity source, whereas elevated GRO may result from nearby safety violations. Highest-concentration DRO samples contained bis-2-ethylhexyl phthalate and N,N-dimethyltetradecylamine. Nevertheless, the overall low rate of contamination for the analytes could be explained by a spatially-resolved hydrogeologic model, where estimated transport distances from gas wells over the relevant timeframes were short relative to the distance to the nearest groundwater wells. Together, the observations and modeled results suggest a low probability of systematic groundwater organic contamination in the region.
Assuntos
Água Subterrânea , Fraturamento Hidráulico , Poluentes Químicos da Água , Monitoramento Ambiental/métodos , Água Subterrânea/química , Metano/análise , Campos de Petróleo e Gás , Pennsylvania , Estados Unidos , Poluentes Químicos da Água/análiseRESUMO
BACKGROUND: Gasdermin B (GSDMB) over-expression promotes poor prognosis and aggressive behavior in HER2 breast cancer by increasing resistance to therapy. Decoding the molecular mechanism of GSDMB-mediated drug resistance is crucial to identify novel effective targeted treatments for HER2/GSDMB aggressive tumors. METHODS: Different in vitro approaches (immunoblot, qRT-PCR, flow cytometry, proteomic analysis, immunoprecipitation, and confocal/electron microscopy) were performed in HER2 breast and gastroesophageal carcinoma cell models. Results were then validated using in vivo preclinical animal models and analyzing human breast and gastric cancer samples. RESULTS: GSDMB up-regulation renders HER2 cancer cells more resistant to anti-HER2 agents by promoting protective autophagy. Accordingly, the combination of lapatinib with the autophagy inhibitor chloroquine increases the therapeutic response of GSDMB-positive cancers in vitro and in zebrafish and mice tumor xenograft in vivo models. Mechanistically, GSDMB N-terminal domain interacts with the key components of the autophagy machinery LC3B and Rab7, facilitating the Rab7 activation during pro-survival autophagy in response to anti-HER2 therapies. Finally, we validated these results in clinical samples where GSDMB/Rab7/LC3B co-expression associates significantly with relapse in HER2 breast and gastric cancers. CONCLUSION: Our findings uncover for the first time a functional link between GSDMB over-expression and protective autophagy in response to HER2-targeted therapies. GSDMB behaves like an autophagy adaptor and plays a pivotal role in modulating autophagosome maturation through Rab7 activation. Finally, our results provide a new and accessible therapeutic approach for HER2/GSDMB + cancers with adverse clinical outcome.
Assuntos
Neoplasias da Mama , Receptor ErbB-2 , Animais , Autofagia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Cloroquina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Lapatinib/farmacologia , Camundongos , Recidiva Local de Neoplasia , Proteômica , Receptor ErbB-2/genética , Peixe-ZebraRESUMO
Peripheral nerve grafts have shown the ability to facilitate central axonal growth and regenerate the adult central nervous system. However, the detailed description of a technique for atraumatic graft placement within the brain is lacking. We present a stereotactic procedure to implant a peripheral nerve graft within a rat's brain with minimal brain tissue damage. The procedure permits a correct graft placement joining two chosen points, and the survival and integration of the graft in the host tissue with a light glial reaction, with evidence of central axonal growth inside the graft, at least up to 8 weeks after its implantation.
Assuntos
Encéfalo/cirurgia , Regeneração Nervosa/fisiologia , Nervo Isquiático/transplante , Técnicas Estereotáxicas , Animais , Encéfalo/ultraestrutura , Microscopia Eletrônica de Transmissão , RatosRESUMO
Vancomycin minimum inhibitory concentrations (MICs) at the upper end of the susceptible range for Staphylococcus aureus have been associated with poor clinical outcomes of bloodstream infections. We tested the hypothesis that high vancomycin MICs in S. aureus bacteraemia isolates are associated with increased cell wall thickness and suboptimal bacterial internalisation or lysis by human phagocytes. In total, 95 isolates were evaluated. Original vancomycin MICs were determined by Etest. The susceptibility of S. aureus isolates to killing by phagocytes was assessed in a human whole blood assay. Internalisation of bacterial cells by phagocytes was investigated by flow cytometry. Cell wall thickness was evaluated by transmission electron microscopy. Genotypic analysis of S. aureus isolates was performed using a DNA microarray system. Vancomycin MICs were significantly higher (P=0.006) in isolates that were killed suboptimally (killing index <60%) compared with those killed efficiently (killing index >70%) and tended to correlate inversely (P=0.08) with the killing indices. Isolates in both killing groups were internalised by human neutrophils and monocytes with comparable efficiency. The cell wall was significantly thicker (P=0.03) in isolates in the low killing group. No genotypic differences were found between the isolates in both killing groups. In summary, high vancomycin MICs in S. aureus bacteraemia isolates were associated with increased cell wall thickness and reduced intracellular killing by phagocytes.
Assuntos
Antibacterianos/farmacologia , Bacteriemia/microbiologia , Parede Celular/ultraestrutura , Fagócitos/imunologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Vancomicina/farmacologia , Endocitose , Citometria de Fluxo , Técnicas de Genotipagem , Humanos , Análise em Microsséries , Testes de Sensibilidade Microbiana , Viabilidade Microbiana , Fagócitos/microbiologia , Staphylococcus aureus/imunologia , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/ultraestruturaRESUMO
Antecedentes: La Red de Salud Global estableció, en enero 2020, una comunidad de práctica para abordar la investigación en COVID-19 en países de ingresos bajos/medios. Objetivo: Identificar prioridades en investigación sobre COVID-19 que requieren atención urgente en América Latina y el Caribe (LAC) y establecer una comunidad de práctica abierta local para apoyar su implementación. Métodos: Estudio exploratorio mixto. Se analizaron los resultados específicos para LAC de una encuesta en línea (enfoque cuantitativo) que evaluó si la agenda prioritaria de investigación para COVID-19 de la OMS sigue siendo pertinente solicitando a los participantes que clasificaran sus tres principales prioridades a corto y largo plazo. Asimismo, se organizó un taller virtual abierto (enfoque cualitativo) el cual fue grabado. Se realizó un análisis temático pragmático a partir de las presentaciones de los panelistas y de las preguntas y comentarios de la audiencia. Se generó un marco de codificación mediante enfoques inductivo y luego deductivo siguiendo la agenda OMS. Resultados: Se contó con 223 participantes de 22 países. Se identificó un consenso sobre los temas de investigación e innovación prioritarios para LAC, dentro y fuera del marco de la agenda OMS, siendo una gran prioridad la necesidad de estudios de ciencias sociales para ayudar a los científicos biomédicos. Discusión: Dado que los casos siguen aumentando en LAC, consideramos que nuestros hallazgos son útiles para orientar tanto a las redes de investigación en la planificación de estudios como a los financiadores en sus decisiones para la asignación de recursos para investigación e innovación...(AU)
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Humanos , Infecções por Coronavirus , América Latina/epidemiologia , Pesquisa Científica e Desenvolvimento Tecnológico , Lacunas da Prática Profissional/éticaRESUMO
Neurons and glia in spinal sensory ganglia derive from multipotent neural crest-derived stem cells. In contrast to neural progenitor cells in the central nervous system, neural crest progenitors coexist with differentiated sensory neurons all throughout the neurogenic period. Thus, developing sensory ganglia are advantageous for determining the possible influence of cell-cell interactions in the regulation of precursor proliferation and neurogenesis. Neurotrophins are important regulators of neuronal survival in the developing vertebrate nervous system and, in addition, they appear to influence precursor behavior in vitro. Studies in mice carrying mutations in neurotrophin genes provide a good system in which to analyze essential actions of these factors on the different developing neural populations.
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Gânglios Espinais/embriologia , Fatores de Crescimento Neural/deficiência , Fatores de Crescimento Neural/genética , Crista Neural/embriologia , Neuroglia/citologia , Neurônios Aferentes/citologia , Células-Tronco/metabolismo , Animais , Diferenciação Celular/fisiologia , Divisão Celular/fisiologia , Gânglios Espinais/citologia , Gânglios Espinais/metabolismo , Camundongos , Crista Neural/citologia , Crista Neural/metabolismo , Neuroglia/metabolismo , Neurônios Aferentes/metabolismo , Receptores de Fator de Crescimento Neural/genética , Receptores de Fator de Crescimento Neural/metabolismo , Células-Tronco/citologiaRESUMO
Although transplantation of adipose-derived stem cells (ADSC) in chronic myocardial infarction (MI) models is associated with functional improvement, its therapeutic value is limited due to poor long-term cell engraftment and survival. Thus, the objective of this study was to examine whether transplantation of collagen patches seeded with ADSC could enhance cell engraftment and improve cardiac function in models of chronic MI. With that purpose, chronically infarcted Sprague-Dawley rats (n = 58) were divided into four groups and transplanted with media, collagen scaffold (CS), rat ADSC, or CS seeded with rat ADSC (CS-rADSC). Cell engraftment, histological changes, and cardiac function were assessed 4 months after transplantation. In addition, Göttingen minipigs (n = 18) were subjected to MI and then transplanted 2 months later with CS or CS seeded with autologous minipig ADSC (CS-pADSC). Functional and histological assessments were performed 3 months post-transplantation. Transplantation of CS-rADSC was associated with increased cell engraftment, significant improvement in cardiac function, myocardial remodeling, and revascularization. Moreover, transplantation of CS-pADSC in the pre-clinical swine model improved cardiac function and was associated with decreased fibrosis and increased vasculogenesis. In summary, transplantation of CS-ADSC resulted in enhanced cell engraftment and was associated with a significant improvement in cardiac function and myocardial remodeling.
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Tecido Adiposo/citologia , Colágeno/administração & dosagem , Modelos Animais de Doenças , Infarto do Miocárdio/cirurgia , Pericárdio , Transplante de Células-Tronco , Animais , Doença Crônica , Coração/fisiopatologia , Infarto do Miocárdio/fisiopatologia , Ratos , Ratos Sprague-Dawley , Suínos , Porco Miniatura , Alicerces TeciduaisRESUMO
Lamin A (LMNA)-linked lipodystrophies may be either genetic (associated with LMNA mutations) or acquired (associated with the use of human immunodeficiency virus protease inhibitors [PIs]), and in both cases they share clinical features such as anomalous distribution of body fat or generalized loss of adipose tissue, metabolic alterations, and early cardiovascular complications. Both LMNA-linked lipodystrophies are characterized by the accumulation of the lamin A precursor prelamin A. The pathological mechanism by which prelamin A accumulation induces the lipodystrophy associated phenotypes remains unclear. Since the affected tissues in these disorders are of mesenchymal origin, we have generated an LMNA-linked experimental model using human mesenchymal stem cells treated with a PI, which recapitulates the phenotypes observed in patient biopsies. This model has been demonstrated to be a useful tool to unravel the pathological mechanism of the LMNA-linked lipodystrophies, providing an ideal system to identify potential targets to generate new therapies for drug discovery screening. We report for the first time that impaired adipogenesis is a consequence of the interaction between accumulated prelamin A and Sp1 transcription factor, sequestration of which results in altered extracellular matrix gene expression. In fact, our study shows a novel, essential, and finely tuned role for Sp1 in adipose lineage differentiation in human mesenchymal stem cells. These findings define a new physiological experimental model to elucidate the pathological mechanisms LMNA-linked lipodystrophies, creating new opportunities for research and treatment not only of LMNA-linked lipodystrophies but also of other adipogenesis-associated metabolic diseases.
Assuntos
Tecido Adiposo/metabolismo , Diferenciação Celular/fisiologia , Metabolismo dos Lipídeos/fisiologia , Células-Tronco Mesenquimais/metabolismo , Proteínas Nucleares/biossíntese , Precursores de Proteínas/biossíntese , Vesículas Secretórias/metabolismo , Fator de Transcrição Sp1/metabolismo , Adipogenia/fisiologia , Tecido Adiposo/citologia , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Regulação da Expressão Gênica/genética , Humanos , Lamina Tipo A , Lipodistrofia/genética , Lipodistrofia/metabolismo , Lipodistrofia/patologia , Células-Tronco Mesenquimais/citologia , Mutação , Proteínas Nucleares/genética , Precursores de Proteínas/genética , Vesículas Secretórias/genética , Fator de Transcrição Sp1/genéticaRESUMO
Fresh adipose-derived cells have been shown to be effective in the treatment of acute myocardial infarction (MI), but their role in the chronic setting is unknown. We sought to determine the long-term effect of the adipose derived-stromal vascular fraction (SVF) cell transplantation in a rat model of chronic MI. MI was induced in 82 rats by permanent coronary artery ligation and 5 weeks later rats were allocated to receive an intramyocardial injection of 10(7) GFP-expressing fresh SVF cells or culture media as control. Heart function and tissue metabolism were determined by echocardiography and (18)F-FDG-microPET, respectively, and histological studies were performed for up to 3 months after transplantation. SVF induced a statistically significant long-lasting (3 months) improvement in cardiac function and tissue metabolism that was associated with increased revascularization and positive heart remodeling, with a significantly smaller infarct size, thicker infarct wall, lower scar fibrosis, and lower cardiac hypertrophy. Importantly, injected cells engrafted and were detected in the treated hearts for at least 3 months, directly contributing to the vasculature and myofibroblasts and at negligible levels to cardiomyocytes. Furthermore, SVF release of angiogenic (VEGF and HGF) and proinflammatory (MCP-1) cytokines, as well as TIMP1 and TIMP4, was demonstrated in vitro and in vivo, strongly suggesting that they have a trophic effect. These results show the potential of SVF to contribute to the regeneration of ischemic tissue and to provide a long-term functional benefit in a rat model of chronic MI, by both direct and indirect mechanisms.