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Drosophila is an important model for studying heart development and disease. Yet, single-cell transcriptomic data of its developing heart have not been performed. Here, we report single-cell profiling of the entire fly heart using â¼3000 Hand-GFP embryos collected at five consecutive developmental stages, ranging from bilateral migrating rows of cardiac progenitors to a fused heart tube. The data revealed six distinct cardiac cell types in the embryonic fly heart: cardioblasts, both Svp+ and Tin+ subtypes; and five types of pericardial cell (PC) that can be distinguished by four key transcription factors (Eve, Odd, Ct and Tin) and include the newly described end of the line PC. Notably, the embryonic fly heart combines transcriptional signatures of the mammalian first and second heart fields. Using unique markers for each heart cell type, we defined their number and location during heart development to build a comprehensive 3D cell map. These data provide a resource to track the expression of any gene in the developing fly heart, which can serve as a reference to study genetic perturbations and cardiac diseases.
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Drosophila melanogaster , Drosophila melanogaster/citologia , Drosophila melanogaster/embriologia , Coração/embriologia , Análise da Expressão Gênica de Célula Única , Linfonodos/citologia , Linfonodos/embriologia , Embrião não Mamífero , Desenvolvimento Embrionário , Biomarcadores , OrganogêneseRESUMO
Indirect nitrous oxide (N2O) emissions from streams and rivers are a poorly constrained term in the global N2O budget. Current models of riverine N2O emissions place a strong focus on denitrification in groundwater and riverine environments as a dominant source of riverine N2O, but do not explicitly consider direct N2O input from terrestrial ecosystems. Here, we combine N2O isotope measurements and spatial stream network modeling to show that terrestrial-aquatic interactions, driven by changing hydrologic connectivity, control the sources and dynamics of riverine N2O in a mesoscale river network within the U.S. Corn Belt. We find that N2O produced from nitrification constituted a substantial fraction (i.e., >30%) of riverine N2O across the entire river network. The delivery of soil-produced N2O to streams was identified as a key mechanism for the high nitrification contribution and potentially accounted for more than 40% of the total riverine emission. This revealed large terrestrial N2O input implies an important climate-N2O feedback mechanism that may enhance riverine N2O emissions under a wetter and warmer climate. Inadequate representation of hydrologic connectivity in observations and modeling of riverine N2O emissions may result in significant underestimations.
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Hidrologia , Óxido Nitroso , Rios , Rios/química , Água Subterrânea/química , Ecossistema , Nitrificação , Solo/química , Monitoramento AmbientalRESUMO
OBJECTIVE: The purpose of this review is to systematically assess primary research publications on known genetic variants, which modify the risk for symptoms or dysfunction persisting 30 days or more following mild traumatic brain injury (mTBI). SUMMARY OF REVIEW: A search of PubMed and Embase from inception through June 2022 identified 42 studies that associated genetic variants with the presence of symptoms or cognitive dysfunction 30 days or more following mTBI. Risk of bias was assessed for each publication using the Newcastle Ottawa Scale (NOS). Fifteen of the 22 studies evaluating apolipoprotein E ( APOE ) É4 concluded that it was associated with worse outcomes and 4 of the 8 studies investigating the brain-derived neurotrophic factor ( BDNF ) reported the Val66Met allele was associated with poorer outcomes. The review also identified 12 studies associating 28 additional variants with mTBI outcomes. Of these, 8 references associated specific variants with poorer outcomes. Aside from analyses comparing carriers and noncarriers of APOE É4 and BDNF Val66Met, most of the reviewed studies were too dissimilar, particularly in terms of specific outcome measures but also in genes examined, to allow for direct comparisons of their findings. Moreover, these investigations were observational and subject to varying degrees of bias. CONCLUSIONS: The most consistent finding across articles was that APOE É4 is associated with persistent post-mTBI impairment (symptoms or cognitive dysfunction) more than 30 days after mTBI. The sparsity of other well-established and consistent findings in the mTBI literature should motivate larger, prospective studies, which characterize the risk for persistent impairment with standardized outcomes in mTBI posed by other genetic variants influencing mTBI recovery.
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Ectomycorrhizal (EM) associations can promote the dominance of tree species in otherwise diverse tropical forests. These EM associations between trees and their fungal mutualists have important consequences for soil organic matter cycling, yet the influence of these EM-associated effects on surrounding microbial communities is not well known, particularly in neotropical forests. We examined fungal and prokaryotic community composition in surface soil samples from mixed arbuscular mycorrhizal (AM) and ectomycorrhizal (EM) stands as well as stands dominated by EM-associated Oreomunnea mexicana (Juglandaceae) in four watersheds differing in soil fertility in the Fortuna Forest Reserve, Panama. We hypothesized that EM-dominated stands would support distinct microbial community assemblages relative to the mixed AM-EM stands due to differences in carbon and nitrogen cycling associated with the dominance of EM trees. We expected that this microbiome selection in EM-dominated stands would lead to lower overall microbial community diversity and turnover, with tighter correspondence between general fungal and prokaryotic communities. We measured fungal and prokaryotic community composition via high-throughput Illumina sequencing of the ITS2 (fungi) and 16S rRNA (prokaryotic) gene regions. We analyzed differences in alpha and beta diversity between forest stands associated with different mycorrhizal types, as well as the relative abundance of fungal functional groups and various microbial taxa. We found that fungal and prokaryotic community composition differed based on stand mycorrhizal type. There was lower prokaryotic diversity and lower relative abundance of fungal saprotrophs and pathogens in EM-dominated than AM-EM mixed stands. However, contrary to our prediction, there was lower homogeneity for fungal communities in EM-dominated stands compared to mixed AM-EM stands. Overall, we demonstrate that EM-dominated tropical forest stands have distinct soil microbiomes relative to surrounding diverse forests, suggesting that EM fungi may filter microbial functional groups in ways that could potentially influence plant performance or ecosystem function.
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Microbiota , Micorrizas , Micorrizas/fisiologia , Solo , RNA Ribossômico 16S , Florestas , Árvores/microbiologia , Microbiologia do Solo , Fungos/genéticaRESUMO
BACKGROUND: Understanding immunogenicity and effectiveness of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines is critical to guide rational use. METHODS: We compared the immunogenicity of mRNA-1273, BNT-162b2, and Ad26.COV2.S in healthy ambulatory adults. We performed an inverse-variance meta-analysis of population-level effectiveness from public health reports inâ >â 40 million individuals. RESULTS: A single dose of either mRNA vaccine yielded comparable antibody and neutralization titers to convalescent individuals. Ad26.COV2.S yielded lower antibody concentrations and frequently undetectable neutralization titers. Bulk and cytotoxic T-cell responses were higher in mRNA1273 and BNT162b2 than Ad26.COV2.S recipients. Regardless of vaccine, <50% of vaccinees demonstrated CD8+ T-cell responses. Antibody concentrations and neutralization titers increased comparably after the first dose of either vaccine, and further in recipients of a second dose. Prior infection was associated with high antibody concentrations and neutralization even after a single dose and regardless of vaccine. Neutralization of Beta, Gamma, and Delta strains were poorer regardless of vaccine. In meta-analysis, relative to mRNA1273 the effectiveness of BNT162b2 was lower against infection and hospitalization, and Ad26COV2.S was lower against infection, hospitalization, and death. CONCLUSIONS: Variation in the immunogenicity correlates with variable effectiveness of the 3 vaccines deployed in the United States.
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Ad26COVS1 , COVID-19 , Vacina de mRNA-1273 contra 2019-nCoV , Adulto , Vacina BNT162 , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , Imunogenicidade da Vacina , SARS-CoV-2/genética , Vacinas Sintéticas , Vacinas de mRNARESUMO
Because genotypes within a species commonly differ in traits that influence other species, whole communities, or even ecosystem functions, evolutionary change within one key species may affect the community and ecosystem processes. Here we use experimental mesocosms to test how the evolution of reduced cooperation in rhizobium mutualists in response to 20 years of nitrogen fertilization compares to the effects of rhizobium presence on soil nitrogen availability and plant community composition and diversity. The evolution of reduced rhizobium cooperation caused reductions in soil nitrogen, biological nitrogen fixation, and leaf nitrogen concentrations that were as strong as, or even stronger than, experimental rhizobium inoculation (presence/absence) treatments. Effects of both rhizobium evolution and rhizobium inoculation on legume dominance, plant community composition, and plant species diversity were often smaller in magnitude, but suggest that rhizobium evolution can alter the relative abundance of plant functional groups. Our findings indicate that the consequences of rapid microbial evolution for ecosystems and communities can rival the effects resulting from the presence or abundance of keystone mutualists.
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Fabaceae , Rhizobium , Ecossistema , Fabaceae/fisiologia , Nitrogênio , Plantas , Rhizobium/fisiologia , Solo , Simbiose/fisiologiaRESUMO
Many biotic and abiotic processes contribute to nitrous oxide (N2 O) production in the biosphere, but N2 O consumption in the environment has heretofore been attributed primarily to canonical denitrifying microorganisms. The nosZ genes encoding the N2 O reductase enzyme, NosZ, responsible for N2 O reduction to dinitrogen are now known to include two distinct groups: the well-studied Clade I which denitrifiers typically possess, and the novel Clade II possessed by diverse groups of microorganisms, most of which are non-denitrifiers. Clade II N2 O reducers could play an important, previously unrecognized role in controlling N2 O emissions for several reasons, including: (1) the consumption of N2 O produced by processes other than denitrification, (2) hypothesized non-respiratory functions of NosZ as an electron sink or for N2 O detoxification, (3) possible differing enzyme kinetics of Clade II NosZ compared to Clade I NosZ, and (4) greater nosZ gene abundance for Clade II compared to Clade I in soils of many ecosystems. Despite the potential ecological significance of Clade II NosZ, a census of 800 peer-reviewed original research articles discussing nosZ and published from 2013 to 2019 showed that the percentage of articles evaluating or mentioning Clade II nosZ increased from 5% in 2013 to only 22% in 2019. The census revealed that the slowly spreading awareness of Clade II nosZ may result in part from disciplinary silos, with the percentage of nosZ articles mentioning Clade II nosZ ranging from 0% in Agriculture and Agronomy journals to 32% in Multidisciplinary Sciences journals. In addition, inconsistent nomenclature for Clade I nosZ and Clade II nosZ, with 17 different terminologies used in the literature, may have created confusion about the two distinct groups of N2 O reducers. We provide recommendations to accelerate advances in understanding the role of the diversity of N2 O reducers in regulating soil N2 O emissions.
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Óxido Nitroso , Solo , Bactérias/genética , Desnitrificação , Ecossistema , Filogenia , Microbiologia do SoloRESUMO
Quantifying changes in soil organic carbon (SOC) stocks and other soil properties is essential for understanding how soils will respond to land management practices and global change. Although they are widely used, comparisons of SOC stocks at fixed depth (FD) intervals are subject to errors when changes in bulk density or soil organic matter occur. The equivalent soil mass (ESM) method has been recommended in lieu of FD for assessing changes in SOC stocks in mineral soils, but ESM remains underutilized for SOC stocks and has rarely been used for other soil properties. In this paper, we draw attention to the limitations of the FD method and demonstrate the advantages of the ESM approach. We provide illustrations to show that the FD approach is susceptible to errors not only for quantifying SOC stocks but also for soil mass-based properties such as SOC mass percent, C:N mass ratio, and δ13 C. We describe the ESM approach and show how it mitigates the FD method limitations. Using bulk density change simulations applied to an empirical dataset from bioenergy cropping systems, we show that the ESM method provides consistently lower errors than FD when quantifying changes in SOC stocks and other soil properties. To simplify the use of ESM, we detail how the method can be integrated into sampling schemes, and we provide an example R computer script that can perform ESM calculations on large datasets. We encourage future studies, whether temporal or comparative, to utilize sampling methods that are amenable to the ESM approach. Overall, we agree with previous recommendations that ESM should be the standard method for evaluating SOC stock changes in mineral soils, but we further suggest that ESM may also be preferred for comparisons of other soil properties including mass percentages, elemental mass ratios, and stable isotope composition.
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Carbono , Solo , Minerais , Nitrogênio/análiseRESUMO
PREMISE: Nutrients, light, water, and temperature are key factors limiting the growth of individual plants in nature. Mutualistic interactions between plants and microbes often mediate resource limitation for both partners. In the mutualism between legumes and rhizobia, plants provide rhizobia with carbon in exchange for fixed nitrogen. Because partner quality in mutualisms is genotype-dependent, within-species genetic variation is expected to alter the responses of mutualists to changes in the resource environment. Here we ask whether partner quality variation in rhizobia mediates the response of host plants to changing light availability, and conversely, whether light alters the expression of partner quality variation. METHODS: We inoculated clover hosts with 11 strains of Rhizobium leguminosarum that differed in partner quality, grew plants under either ambient or low light conditions in the greenhouse, and measured plant growth, nodule traits, and foliar nutrient composition. RESULTS: Light availability and rhizobium inoculum interactively determined plant growth, and variation in rhizobium partner quality was more apparent in ambient light. CONCLUSIONS: Our results suggest that variation in the costs and benefits of rhizobium symbionts mediate host responses to light availability and that rhizobium strain variation might more important in higher-light environments. Our work adds to a growing appreciation for the role of microbial intraspecific and interspecific diversity in mediating extended phenotypes in their hosts and suggests an important role for light availability in the ecology and evolution of legume-rhizobium symbiosis.
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Fabaceae , Rhizobium , Genótipo , Fixação de Nitrogênio , SimbioseRESUMO
Chronic myelomonocytic leukemia (CMML) and juvenile myelomonocytic leukemia (JMML) are myelodysplastic syndrome (MDS)/myeloproliferative neoplasm (MPN) overlap disorders characterized by monocytosis, myelodysplasia, and a characteristic hypersensitivity to granulocyte-macrophage colony-stimulating factor (GM-CSF). Currently, there are no available disease-modifying therapies for CMML, nor are there preclinical models that fully recapitulate the unique features of CMML. Through use of immunocompromised mice with transgenic expression of human GM-CSF, interleukin-3, and stem cell factor in a NOD/SCID-IL2Rγnull background (NSGS mice), we demonstrate remarkable engraftment of CMML and JMML providing the first examples of serially transplantable and genetically accurate models of CMML. Xenotransplantation of CD34+ cells (n = 8 patients) or unfractionated bone marrow (BM) or peripheral blood mononuclear cells (n = 10) resulted in robust engraftment of CMML in BM, spleen, liver, and lung of recipients (n = 82 total mice). Engrafted cells were myeloid-restricted and matched the immunophenotype, morphology, and genetic mutations of the corresponding patient. Similar levels of engraftment were seen upon serial transplantation of human CD34+ cells in secondary NSGS recipients (2/5 patients, 6/11 mice), demonstrating the durability of CMML grafts and functionally validating CD34+ cells as harboring the disease-initiating compartment in vivo. Successful engraftments of JMML primary samples were also achieved in all NSGS recipients (n = 4 patients, n = 12 mice). Engraftment of CMML and JMML resulted in overt phenotypic abnormalities and lethality in recipients, which facilitated evaluation of the JAK2/FLT3 inhibitor pacritinib in vivo. These data reveal that NSGS mice support the development of CMML and JMML disease-initiating and mature leukemic cells in vivo, allowing creation of genetically accurate preclinical models of these disorders.
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Hidrocarbonetos Aromáticos com Pontes/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielomonocítica Juvenil/tratamento farmacológico , Síndromes Mielodisplásicas/tratamento farmacológico , Pirimidinas/farmacologia , Animais , Feminino , Xenoenxertos , Humanos , Janus Quinase 2/antagonistas & inibidores , Janus Quinase 2/genética , Janus Quinase 2/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Leucemia Mielomonocítica Juvenil/genética , Leucemia Mielomonocítica Juvenil/metabolismo , Leucemia Mielomonocítica Juvenil/patologia , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Síndromes Mielodisplásicas/metabolismo , Síndromes Mielodisplásicas/patologia , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Transplante de Neoplasias , Ensaios Antitumorais Modelo de Xenoenxerto , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidores , Tirosina Quinase 3 Semelhante a fms/genética , Tirosina Quinase 3 Semelhante a fms/metabolismoRESUMO
BACKGROUND: Pediatric pelvic fractures are rare. The contribution of pelvic fracture pattern, risk factors for associated injuries, and mortality are poorly defined in this population. METHODS: Patients aged 0-17 with pelvic fractures at a level I trauma center over a 20-y period were reviewed. Fracture patterns were classified according to the Young-Burgess classification when applicable. Fractures were analyzed for location, pubic symphysis or sacroiliac widening, and contrast extravasation. RESULTS: There were 163 pelvic fractures in 8758 admissions (incidence 2%). The most common associated injures were extremity fractures (60%, n = 98), abdominal solid organ (55%, n = 89), and chest (48%, n = 78), with the majority (61%, n = 99) sustaining injuries to multiple organs. Unstable fractures were associated with injures to the thorax (70% versus 40%), heart (15% versus 2%), and spleen (40% versus 18%), all P < 0.05. Nonpelvic operative interventions were required in 45% (n = 73) and were more common in unstable fractures (36% versus 19%), contrast extravasation (63% versus 26%), sacroiliac widening (36% versus 20%), and sacral fractures (39% versus 13%), all P < 0.05. Mortality was 13% and higher in males versus females (18% versus 5%), contrast extravasation (50% versus 3%), or sacroiliac/pubic symphysis widening (13% versus 2%) (all P < 0.05). Male gender (OR 6.03), brain injury (OR 6.18), spine injury (OR 5.06), and cardiac injury (OR 35.0) were independently associated with mortality (all P < 0.05). CONCLUSIONS: Pediatric pelvic fractures are rare but critical injuries associated with significant morbidity and need for interventions. Increasing fracture severity corresponds to injuries to other body systems and increased mortality.
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Fraturas Ósseas/epidemiologia , Ossos Pélvicos/lesões , Centros de Traumatologia/estatística & dados numéricos , Adolescente , Criança , Pré-Escolar , Feminino , Florida/epidemiologia , Fraturas Ósseas/cirurgia , Humanos , Lactente , Escala de Gravidade do Ferimento , Masculino , Traumatismo Múltiplo/epidemiologia , Estudos RetrospectivosRESUMO
Annual row crops dominate agriculture around the world and have considerable negative environmental impacts, including significant greenhouse gas emissions. Transformative land-use solutions are necessary to mitigate climate change and restore critical ecosystem services. Alley cropping (AC)-the integration of trees with crops-is an agroforestry practice that has been studied as a transformative, multifunctional land-use solution. In the temperate zone, AC has strong potential for climate change mitigation through direct emissions reductions and increases in land-use efficiency via overyielding compared to trees and crops grown separately. In addition, AC provides climate change adaptation potential and ecological benefits by buffering alley crops to weather extremes, diversifying income to hedge financial risk, increasing biodiversity, reducing soil erosion, and improving nutrient- and water-use efficiency. The scope of temperate AC research and application has been largely limited to simple systems that combine one timber tree species with an annual grain. We propose two frontiers in temperate AC that expand this scope and could transform its climate-related benefits: (i) diversification via woody polyculture and (ii) expanded use of tree crops for food and fodder. While AC is ready now for implementation on marginal lands, we discuss key considerations that could enhance the scalability of the two proposed frontiers and catalyze widespread adoption.
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Agricultura/métodos , Produtos Agrícolas , Ecossistema , Solo , Agricultura/tendências , Biodiversidade , Mudança Climática , ÁrvoresRESUMO
Recent controversies surrounding the authenticity of c-kit+ cardiac progenitor cells significantly push back the advance in regenerative therapies for cardiovascular diseases. There is an urgent need for research in characterizing alternative types of cardiac progenitor cells. Towards this goal, in the present study, we determined the effect of maternal diabetes on Sca1+ cardiac progenitor cells. Maternal diabetes induced caspase 3-dependent apoptosis in Sca1+ cardiac progenitor cells derived from embryonic day 17.5 (E17.5). Similarly, high glucose in vitro but not the glucose osmotic control mannitol triggered Sca1+ cardiac progenitor cell apoptosis in a dose- and time-dependent manner. Both maternal diabetes and high glucose in vitro activated the pro-apoptotic transcription factor, Forkhead O 3a (FoxO3a) via dephosphorylation at threonine 32 (Thr-32) residue. foxo3a gene deletion abolished maternal diabetes-induced Sca1+ cardiac progenitor cell apoptosis. The dominant negative FoxO3a mutant without the transactivation domain from the C terminus blocked high glucose-induced Sca1+ cardiac progenitor cell apoptosis, whereas the constitutively active FoxO3a mutant with the three phosphorylation sites, Thr-32, Ser-253, and Ser-315, being replaced by alanine residues mimicked the pro-apoptotic effect of high glucose. Thus, maternal diabetes and high glucose in vitro may limit the regenerative potential of Sca1+ cardiac progenitor cells by inducing apoptosis through FoxO3a activation. These findings will serve as the guide in optimizing the autologous therapy using Sca1+ cardiac progenitor cells in cardiac defect babies born exposed to maternal diabetes.
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Ataxina-1/metabolismo , Caspase 3/metabolismo , Diabetes Gestacional/patologia , Proteína Forkhead Box O3/metabolismo , Glucose/metabolismo , Miocárdio/patologia , Células-Tronco/patologia , Animais , Apoptose , Diabetes Gestacional/genética , Diabetes Gestacional/metabolismo , Embrião de Mamíferos/citologia , Embrião de Mamíferos/patologia , Feminino , Proteína Forkhead Box O3/genética , Deleção de Genes , Coração/embriologia , Cardiopatias Congênitas/etiologia , Cardiopatias Congênitas/genética , Cardiopatias Congênitas/metabolismo , Cardiopatias Congênitas/patologia , Camundongos Endogâmicos C57BL , Miocárdio/citologia , Miocárdio/metabolismo , Gravidez , Células-Tronco/citologia , Células-Tronco/metabolismoRESUMO
Low-grade chronic inflammation plays an important role in the pathogenesis of obesity-induced insulin resistance. ABCA1 is essential for reverse cholesterol transport and HDL synthesis, and protects against macrophage inflammation. In the present study, the effects of ABCA1 deficiency in hematopoietic cells on diet-induced inflammation and insulin resistance were tested in vivo using bone marrow transplanted (BMT)-WT and BMT-ABCA1(-/-) mice. When challenged with a high-fat high-carbohydrate diabetogenic diet with added cholesterol (HFHSC), BMT-ABCA1(-/-) mice displayed enhanced insulin resistance and impaired glucose tolerance as compared with BMT-WT mice. The worsened insulin resistance and impaired glucose tolerance in BMT-ABCA1(-/-) mice were accompanied by increased macrophage accumulation and inflammation in adipose tissue and liver. Moreover, BMT-ABCA1(-/-) mice had significantly higher hematopoietic stem cell proliferation, myeloid cell expansion, and monocytosis when challenged with the HFHSC diet. In vitro studies indicated that macrophages from ABCA1(-/-) mice showed significantly increased inflammatory responses induced by saturated fatty acids. Taken together, these studies point to an important role for hematopoietic ABCA1 in modulating a feed-forward mechanism in obesity such that inflamed tissue macrophages stimulate the production of more monocytes, leading to an exacerbation of inflammation and associated disease processes.
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Transportador 1 de Cassete de Ligação de ATP/deficiência , Resistência à Insulina/fisiologia , Transportador 1 de Cassete de Ligação de ATP/sangue , Transportador 1 de Cassete de Ligação de ATP/genética , Tecido Adiposo/metabolismo , Animais , Colesterol/metabolismo , Colesterol/farmacologia , Dieta Hiperlipídica , Intolerância à Glucose/metabolismo , Inflamação/metabolismo , Inflamação/patologia , Fígado/metabolismo , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos DBA , Monócitos/metabolismo , Monócitos/patologia , Transtornos Mieloproliferativos/genética , Transtornos Mieloproliferativos/metabolismo , Transtornos Mieloproliferativos/patologia , Obesidade/patologia , Receptores de LDL/metabolismoRESUMO
Development of the endocrine compartment of the pancreas, as represented by the islets of Langerhans, occurs through a series of highly regulated events encompassing branching of the pancreatic epithelium, delamination and differentiation of islet progenitors from ductal domains, followed by expansion and three-dimensional organization into islet clusters. Cellular interactions with the extracellular matrix (ECM) mediated by receptors of the integrin family are postulated to regulate key functions in these processes. Yet, specific events regulated by these receptors in the developing pancreas remain unknown. Here, we show that ablation of the ß1 integrin gene in developing pancreatic ß-cells reduces their ability to expand during embryonic life, during the first week of postnatal life, and thereafter. Mice lacking ß1 integrin in insulin-producing cells exhibit a dramatic reduction of the number of ß-cells to only â¼18% of wild-type levels. Despite the significant reduction in ß-cell mass, these mutant mice are not diabetic. A thorough phenotypic analysis of ß-cells lacking ß1 integrin revealed a normal expression repertoire of ß-cell markers, normal architectural organization within islet clusters, and a normal ultrastructure. Global gene expression analysis revealed that ablation of this ECM receptor in ß-cells inhibits the expression of genes regulating cell cycle progression. Collectively, our results demonstrate that ß1 integrin receptors function as crucial positive regulators of ß-cell expansion.
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Proliferação de Células , Regulação da Expressão Gênica no Desenvolvimento , Células Secretoras de Insulina/metabolismo , Integrina beta1/metabolismo , Animais , Adesão Celular , Contagem de Células , Ciclo Celular , Diferenciação Celular , Membrana Celular/metabolismo , Forma Celular , Células Cultivadas , Embrião de Mamíferos/metabolismo , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Insulina/genética , Insulina/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/ultraestrutura , Integrina beta1/genética , Camundongos , Camundongos Knockout , Microscopia Eletrônica de Transmissão , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Fosforilação , Regiões Promotoras GenéticasRESUMO
Sea level rise will change inundation regimes in salt marshes, altering redox dynamics that control nitrification - a potential source of the potent greenhouse gas, nitrous oxide (N2 O) - and denitrification, a major nitrogen (N) loss pathway in coastal ecosystems and both a source and sink of N2 O. Measurements of net N2 O fluxes alone yield little insight into the different effects of redox conditions on N2 O production and consumption. We used in situ measurements of gross N2 O fluxes across a salt marsh elevation gradient to determine how soil N2 O emissions in coastal ecosystems may respond to future sea level rise. Soil redox declined as marsh elevation decreased, with lower soil nitrate and higher ferrous iron in the low marsh compared to the mid and high marshes (P < 0.001 for both). In addition, soil oxygen concentrations were lower in the low and mid-marshes relative to the high marsh (P < 0.001). Net N2 O fluxes differed significantly among marsh zones (P = 0.009), averaging 9.8 ± 5.4 µg N m(-2) h(-1) , -2.2 ± 0.9 µg N m(-2) h(-1) , and 0.67 ± 0.57 µg N m(-2) h(-1) in the low, mid, and high marshes, respectively. Both net N2 O release and uptake were observed in the low and high marshes, but the mid-marsh was consistently a net N2 O sink. Gross N2 O production was highest in the low marsh and lowest in the mid-marsh (P = 0.02), whereas gross N2 O consumption did not differ among marsh zones. Thus, variability in gross N2 O production rates drove the differences in net N2 O flux among marsh zones. Our results suggest that future studies should focus on elucidating controls on the processes producing, rather than consuming, N2 O in salt marshes to improve our predictions of changes in net N2 O fluxes caused by future sea level rise.
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Ciclo do Nitrogênio , Óxido Nitroso/análise , Solo/química , Áreas Alagadas , California , Desnitrificação , Monitoramento Ambiental , Nitrificação , Oxigênio/análise , Água do MarRESUMO
CONTEXT: Laparoscopic surgery is commonly used for the treatment of many pediatric surgical diseases at our department. Single-incision laparoscopic surgery (SILS) is well-known for its cosmetic benefit. We, hereby, present our experience of SILS and evaluate its efficacy. MATERIALS AND METHODS: From July 2012 to June 2014, 78 patients aged less than 18 years who underwent SILS were retrospectively evaluated. There were 44 males and 34 females, with a mean age of 10.3 years. The procedures included appendectomy (n = 64), reduction of intussusception (n = 8), removal of an intestinal foreign body (n = 3), and Meckel's diverticulectomy (n = 3). We compared the patients who underwent SILS with those who underwent conventional laparoscopic surgery (CLS), regarding these procedures. The parameters for analysis included the patient's demographic data, surgical indication, complications, operative time, and length of hospital stay. CONCLUSION: SILS is comparable to CLS regarding two major procedures, namely, appendectomy and reduction of intussusception. There were no significant differences between the two groups regarding the patients' demographic data, complications, and length of hospital stay. According to our experience of SILS, it could be a feasible and safe procedure for the treatment of various pediatric surgical diseases. However, large prospective randomized studies are needed to identify the differences between SIL and CLS.
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Changes in the redox state of iron (Fe) can be coupled to the biogeochemical cycling of carbon (C), nitrogen, and phosphorus, and thus regulate soil C, ecosystem nutrient availability, and greenhouse gas production. However, its importance broadly in non-flooded upland terrestrial ecosystems is unknown. We measured Fe reduction in soil samples from an annual grassland, a drained peatland, and a humid tropical forest We incubated soil slurries in an anoxic glovebox for 5.5 days and added sodium acetate daily at rates up to 0.4 mg C x (g soil)(-1) x d(-1). Soil moisture, poorly crystalline Fe oxide concentrations, and Fe(II) concentrations differed among study sites in the following order: annual grassland < drained peatland < tropical forest (P < 0.001 for all characteristics). All of the soil samples demonstrated high Fe reduction potential with maximum rates over the course of the incubation averaging 1706 ± 66, 2016 ± 12, and 2973 ± 115 µg Fe x (g soil)(-1) x d(-1) (mean ± SE) for the tropical forest, annual grassland, and drained peatland, respectively. Our results suggest that upland soils from diverse ecosystems have the potential to exhibit high short-term rates of Fe reduction that may play an important role in driving soil biogeochemical processes during periods of anaerobiosis.
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Ferro/química , Solo/química , California , Ecossistema , Oxirredução , Porto RicoRESUMO
Gastrointestinal stromal tumors (GISTs) are neoplasms of neural cells in the gastrointestinal tract; they typically develop in older adults, with less than 10% of cases presenting among patients under the age of 40. This report describes the clinical course and management of a 28-year-old woman with a history of irritable bowel syndrome (IBS) who presented with acute upper abdominal pain. Surgical pathology confirmed a diagnosis of metastatic GIST. The patient underwent imatinib therapy and subsequent surgical tumor debulking. Postoperatively, she presented with acute appendicitis, for which she eventually required appendectomy, and she became pregnant approximately 1 year after the initial diagnosis. This case highlights several treatment challenges that may be encountered in young patients presenting with GIST.
RESUMO
Strain differences have been reported for motor behaviors, and only a subset of spinal cord injury (SCI) patients develop neuropathic pain, implicating genetic or genomic contribution to this condition. Here, we evaluated neuropsychiatric behaviors in A/J, BALB/c, and C57BL/6 male mice and tested genetic or genomic alterations following SCI. A/J and BALB/c naive mice showed significantly less locomotor activity and greater anxiety-like behavior than C57BL/6 mice. Although SCI elicited locomotor dysfunction, C57BL/6 and A/J mice showed the best and the worst post-traumatic recovery, respectively. Mild (m)-SCI mice showed deficits in gait dynamics. All moderate/severe SCI mice exhibited similar degrees of anxiety/depression. mSCI in BALB/c and A/J mice resulted in depression, whereas C57BL/6 mice did not exhibit depression. mSCI mice had significantly lower mechanical thresholds than their controls, indicating high cutaneous hypersensitivity. C57BL/6, but not A/J and BLAB/c mice, showed significantly lower heat thresholds than their controls. C57BL/6 mice exhibited spontaneous pain. RNAseq showed that genes in immune responses and wound healing were upregulated, although A/J mice showed the largest increase. The cell cycle and the truncated isoform of trkB genes were robustly elevated in SCI mice. Thus, different genomics are associated with post-traumatic recovery, underscoring the likely importance of genetic factors in SCI.