Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Plant J ; 118(5): 1668-1688, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38407828

RESUMO

Bioenergy sorghum is a low-input, drought-resilient, deep-rooting annual crop that has high biomass yield potential enabling the sustainable production of biofuels, biopower, and bioproducts. Bioenergy sorghum's 4-5 m stems account for ~80% of the harvested biomass. Stems accumulate high levels of sucrose that could be used to synthesize bioethanol and useful biopolymers if information about cell-type gene expression and regulation in stems was available to enable engineering. To obtain this information, laser capture microdissection was used to isolate and collect transcriptome profiles from five major cell types that are present in stems of the sweet sorghum Wray. Transcriptome analysis identified genes with cell-type-specific and cell-preferred expression patterns that reflect the distinct metabolic, transport, and regulatory functions of each cell type. Analysis of cell-type-specific gene regulatory networks (GRNs) revealed that unique transcription factor families contribute to distinct regulatory landscapes, where regulation is organized through various modes and identifiable network motifs. Cell-specific transcriptome data was combined with known secondary cell wall (SCW) networks to identify the GRNs that differentially activate SCW formation in vascular sclerenchyma and epidermal cells. The spatial transcriptomic dataset provides a valuable source of information about the function of different sorghum cell types and GRNs that will enable the engineering of bioenergy sorghum stems, and an interactive web application developed during this project will allow easy access and exploration of the data (https://mc-lab.shinyapps.io/lcm-dataset/).


Assuntos
Biocombustíveis , Parede Celular , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Caules de Planta , Sorghum , Transcriptoma , Sorghum/genética , Sorghum/metabolismo , Caules de Planta/genética , Caules de Planta/metabolismo , Parede Celular/metabolismo , Parede Celular/genética , Perfilação da Expressão Gênica
2.
Pediatr Blood Cancer ; 69(10): e29770, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35593532

RESUMO

BACKGROUND: Medulloblastoma is the most common malignant brain tumor in children. While survival has improved in high-income countries (HIC), the outcomes for patients in low-to-middle-income countries (LMIC) are unclear. Therefore, we sought to determine the survival of children with medulloblastoma at the Instituto Nacional de Enfermedades Neoplasicas (INEN) between 1997 and 2013 in Peru. METHODS: Between 1997 and 2013, data from 103 children older than 3 years with medulloblastoma were analyzed. Fourteen patients were excluded. The patients were split into two distinct cohorts, 1997-2008 and 2009-2013, corresponding with chemotherapy regimen changes. Event-free (EFS) and overall survival (OS) were calculated using the Kaplan-Meier method, whereas prognostic factors were determined by univariate analysis (log-rank test). RESULTS: Eighty-nine patients were included; median age was 8.1 years (range: 3-13.9 years). The 5-year OS was 62% (95% CI: 53%-74%), while EFS was 57% (95% CI: 48%-69%). The variables adversely affecting survival were anaplastic histology (compared to desmoplastic; OS: HR = 3.4, p = .03), metastasis (OS: HR = 3.5, p = .01; EFS: HR = 4.3, p = .004), delay in radiation therapy of 31-60 days (compared to ≤30 days; EFS: HR = 2.1, p = .04), and treatment 2009-2013 cohort (OS: HR = 2.2, p = .02; EFS: HR = 2.0, p = .03). CONCLUSIONS: Outcomes for medulloblastoma at INEN were low compared with HIC. Anaplastic subtype, metastasis at diagnosis, delay in radiation therapy, and treatment in the period 2009-2013 negatively affected the outcomes in our study. Multidisciplinary teamwork, timely delivery of treatment, and partnerships with loco-regional groups and colleagues in HIC is likely beneficial.


Assuntos
Neoplasias Encefálicas , Neoplasias Cerebelares , Meduloblastoma , Adolescente , Neoplasias Cerebelares/patologia , Criança , Pré-Escolar , Intervalo Livre de Doença , Humanos , Meduloblastoma/patologia , Peru/epidemiologia , Prognóstico , Fatores de Risco
3.
Adv Exp Med Biol ; 1258: 111-123, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32767237

RESUMO

Outcomes for young people diagnosed with osteosarcoma hinge almost exclusively on whether they develop lung metastasis. The striking predilection that osteosarcoma shows for metastatic spread to lung suggests properties and/or lung interactions that generate tissue-specific survival and proliferation advantages. While these mechanisms remain overall poorly defined, studies have begun to describe biological elements important to metastasis. Mechanisms described to date include both cell-autonomous adaptations that allow disseminated tumor cells to survive the stressors imposed by metastasis and intercellular signaling networks that tumor cells exploit to pirate needed signals from surrounding tissues or to recruit other cells that create a more favorable niche. Evidence suggests that cell-autonomous changes are largely driven by epigenetic reprogramming of disseminated tumor cells that facilitates resistance to late apoptosis, manages endoplasmic reticulum (ER) stressors, promotes translation of complex transcripts, and activates clotting pathways. Tumor-host signaling pathways important for lung colonization drive interactions with lung epithelium, mesenchymal stem cells, and mediators of innate and adaptive immunity. In this chapter, we highlight one particular pathway that integrates cell-autonomous adaptations with lung-specific tumor-host interactions. In this mechanism, aberrant ΔNp63 expression primes tumor cells to produce IL6 and CXCL8 upon interaction with lung epithelial cells. This tumor-derived IL6 and CXCL8 then initiates autocrine, osteosarcoma-lung paracrine, and osteosarcoma-immune paracrine interactions that facilitate metastasis. Importantly, many of these pathways appear targetable with clinically feasible therapeutics. Ongoing work to better understand metastasis is driving efforts to improve outcomes by targeting the most devastating complication of this disease.


Assuntos
Neoplasias Ósseas/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/secundário , Pulmão/patologia , Osteossarcoma/patologia , Transdução de Sinais/efeitos dos fármacos , Neoplasias Ósseas/tratamento farmacológico , Proliferação de Células , Humanos , Pulmão/efeitos dos fármacos , Neoplasias Pulmonares/patologia , Osteossarcoma/tratamento farmacológico
4.
J Neurol Neurosurg Psychiatry ; 89(8): 866-869, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29487169

RESUMO

OBJECTIVES: Early neurological deterioration prompting urgent brain imaging occurs in nearly 15% of patients with ischaemic stroke receiving intravenous tissue plasminogen activator (tPA). We aim to determine risk factors associated with symptomatic intracranial haemorrhage (sICH) in patients with ischaemic stroke undergoing emergent brain imaging for early neurological deterioration after receiving tPA. METHODS: We abstracted data from our prospective stroke database and included all patients receiving tPA for ischaemic stroke between 1 March 2015 and 1 March 2017. We then identified patients with neurological deterioration who underwent urgent brain imaging prior to their per-protocol surveillance imaging and divided patients into two groups: those with and without sICH. We compared baseline demographics, clinical variables, in-hospital treatments and functional outcomes at 90 days between the two groups. RESULTS: We identified 511 patients who received tPA, of whom 108 (21.1%) had an emergent brain CT. Of these patients, 17.5% (19/108) had sICH; 21.3% (23/108) of emergent scans occurred while tPA was infusing, though only 4.3% of these scans (1/23) revealed sICH. On multivariable analyses, the only predictor of sICH was a change in level of consciousness (OR 6.62, 95% CI 1.64 to 26.70, P=0.008). CONCLUSION: Change in level of consciousness is associated with sICH among patients undergoing emergent brain imaging after receiving tPA. In this group of patients, preparation of tPA reversal agents while awaiting brain imaging may reduce reversal times. Future studies are needed to study the cost-effectiveness of this approach.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Fibrinolíticos/efeitos adversos , Hemorragias Intracranianas/induzido quimicamente , Acidente Vascular Cerebral/tratamento farmacológico , Ativador de Plasminogênio Tecidual/efeitos adversos , Administração Intravenosa , Idoso , Idoso de 80 Anos ou mais , Feminino , Fibrinolíticos/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Terapia Trombolítica/efeitos adversos , Ativador de Plasminogênio Tecidual/uso terapêutico
5.
Epilepsy Behav ; 88: 123-129, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30268021

RESUMO

BACKGROUND: The available information on postictal semiology and behavior in patients with psychogenic nonepileptic seizure (PNES) is limited. In this study, we explore the differences in postictal semiology and behavior between patients with epileptic seizure (ES) and PNES and focus on clinical features that may be helpful in differentiating these two conditions. METHODS: In this retrospective study, video-electroencephalograph (video-EEG) of 144 seizures from 64 patients with PNES and 66 seizures from 42 patients with ES were reviewed. Three novel postictal behaviors were compared between the two groups: a) abrupt, brief, and rapid blinking or shaking of the head as if regaining sensorium or "coming out" of the ictal event; b) looking around the room with a scanning and uncertain look; c) posing a question of "what happened?" or a similar question to the others present in the room. In addition, differences in several other postictal characteristics were studied. RESULTS: At least one of the three specific postictal behaviors was seen in 20.1% of patients with PNES but none of the patients with ES resulting in 100% specificity and 36% sensitivity. While mean ictal duration was significantly longer in patients with PNES (175.3 ±â€¯168 s) compared to ES (105.4 ±â€¯102.9 s), the interval between the end of ictal episode and first correct verbal response (74.5 ±â€¯126.2 s versus 139.4 ±â€¯185.4 s), or first followed command (84.1 ±â€¯133.8 s versus 141.1 ±â€¯192.1 s) were shorter. In the group with PNES, 59.7% of patients demonstrated a whispering or altered voice during the first correct verbal response versus 21.2% of patients in the group with ES. The first followed command was slow or erroneous in 49.3% of the patients with PNES and in 19.7% of the patients with ES. CONCLUSION: In this study, we found significant differences between postictal semiology and behavior of patients with PNES and ES that can be helpful tools in distinguishing between these two conditions. Specifically, three novel postictal behaviors were studied and were found to have a high specificity, but low sensitivity, in distinguishing PNES from ES.


Assuntos
Epilepsia/diagnóstico , Epilepsia/psicologia , Convulsões/diagnóstico , Convulsões/psicologia , Adulto , Estudos de Casos e Controles , Diagnóstico Diferencial , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e Especificidade
6.
J Exp Bot ; 65(13): 3737-47, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24958895

RESUMO

Miscanthus × giganteus is exceptional among C4 plants in its ability to acclimate to chilling (≤14 °C) and maintain a high photosynthetic capacity, in sharp contrast to maize, leading to very high productivity even in cool temperate climates. To identify the mechanisms that underlie this acclimation, RNA was isolated from M × giganteus leaves in chilling and nonchilling conditions and hybridized to microarrays developed for its close relative Zea mays. Among 21 000 array probes that yielded robust signals, 723 showed significant expression change under chilling. Approximately half of these were for annotated genes. Thirty genes associated with chloroplast membrane function were all upregulated. Increases in transcripts for the lhcb5 (chlorophyll a/b-binding protein CP26), ndhF (NADH dehydrogenase F, chloroplast), atpA (ATP synthase alpha subunit), psbA (D1), petA (cytochrome f), and lhcb4 (chlorophyll a/b-binding protein CP29), relative to housekeeping genes in M. × giganteus, were confirmed by quantitative reverse-transcription PCR. In contrast, psbo1, lhcb5, psbA, and lhcb4 were all significantly decreased in Z. mays after 14 days of chilling. Western blot analysis of the D1 protein and LHCII type II chlorophyll a/b-binding protein also showed significant increases in M. × giganteus during chilling and significant decreases in Z. mays. Compared to other C4 species, M. × giganteus grown in chilling conditions appears to counteract the loss of photosynthetic proteins and proteins protecting photosystem II typically observed in other species by increasing mRNA levels for their synthesis.


Assuntos
Adaptação Fisiológica , Dióxido de Carbono/metabolismo , Fotossíntese , Complexo de Proteína do Fotossistema II/metabolismo , Poaceae/genética , Proteínas de Ligação à Clorofila/genética , Proteínas de Ligação à Clorofila/metabolismo , Temperatura Baixa , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Luz , Modelos Biológicos , Análise de Sequência com Séries de Oligonucleotídeos , Folhas de Planta/genética , Folhas de Planta/fisiologia , Folhas de Planta/efeitos da radiação , Poaceae/fisiologia , Poaceae/efeitos da radiação , RNA de Plantas/genética , Zea mays/genética , Zea mays/fisiologia
7.
Artigo em Inglês | MEDLINE | ID: mdl-38724887

RESUMO

The neurodegenerative effects alcohol use disorder (AUD) have been well characterized and are likely due to the long-term effects of alcohol on the brain. The molecular events that underlie regional neuronal loss are a focus of current research. Chronic inflammation in the central nervous system, termed neuroinflammation, contributes to the progressive loss of neurons in the brain. Using data from genome-wide association studies and genetic and gene expression data, α-synuclein was identified as a gene of interest for AUD almost 10 years ago. Despite this and the well-recognized role of α-synuclein in mediating neuroinflammation in other neurodegenerative diseases, its role in alcohol-induced brain damage and AUD is yet to be elucidated. This systematic literature review quantifies and analyzes relationships between AUD, α-synuclein, and neuroinflammation. The review identified fewer studies focused on the role in AUD of α-synuclein (30) than on neuroinflammation (177), with published studies heavily centered on the myeloid differentiation primary response 88 (MyD88)-dependent toll-like receptor 4 (TLR4) pathway. The systematic review revealed that no original literature investigates the roles of α-synuclein and neuroinflammation in AUD and that there are significantly fewer published articles on the role of α-synuclein in AUD than in other neuroinflammatory conditions. Studies of the role of neuroinflammation in AUD are largely centered on the TLR4 signaling cascade, followed by TLR2 and TLR3, and soluble cytokines such as IL-10, IL-1ß, and TNF-α. Key research themes identified in other neurodegenerative disorders provide new insights for further investigation in AUD.

8.
BMC Genomics ; 14: 864, 2013 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-24320546

RESUMO

BACKGROUND: The Miscanthus genus of perennial C4 grasses contains promising biofuel crops for temperate climates. However, few genomic resources exist for Miscanthus, which limits understanding of its interesting biology and future genetic improvement. A comprehensive catalog of expressed sequences were generated from a variety of Miscanthus species and tissue types, with an emphasis on characterizing gene expression changes in spring compared to fall rhizomes. RESULTS: Illumina short read sequencing technology was used to produce transcriptome sequences from different tissues and organs during distinct developmental stages for multiple Miscanthus species, including Miscanthus sinensis, Miscanthus sacchariflorus, and their interspecific hybrid Miscanthus × giganteus. More than fifty billion base-pairs of Miscanthus transcript sequence were produced. Overall, 26,230 Sorghum gene models (i.e., ~ 96% of predicted Sorghum genes) had at least five Miscanthus reads mapped to them, suggesting that a large portion of the Miscanthus transcriptome is represented in this dataset. The Miscanthus × giganteus data was used to identify genes preferentially expressed in a single tissue, such as the spring rhizome, using Sorghum bicolor as a reference. Quantitative real-time PCR was used to verify examples of preferential expression predicted via RNA-Seq. Contiguous consensus transcript sequences were assembled for each species and annotated using InterProScan. Sequences from the assembled transcriptome were used to amplify genomic segments from a doubled haploid Miscanthus sinensis and from Miscanthus × giganteus to further disentangle the allelic and paralogous variations in genes. CONCLUSIONS: This large expressed sequence tag collection creates a valuable resource for the study of Miscanthus biology by providing detailed gene sequence information and tissue preferred expression patterns. We have successfully generated a database of transcriptome assemblies and demonstrated its use in the study of genes of interest. Analysis of gene expression profiles revealed biological pathways that exhibit altered regulation in spring compared to fall rhizomes, which are consistent with their different physiological functions. The expression profiles of the subterranean rhizome provides a better understanding of the biological activities of the underground stem structures that are essentials for perenniality and the storage or remobilization of carbon and nutrient resources.


Assuntos
Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Poaceae/genética , Rejuvenescimento , Rizoma/genética , Transcriptoma , Análise por Conglomerados , Evolução Molecular , Interação Gene-Ambiente , Sequenciamento de Nucleotídeos em Larga Escala , Dados de Sequência Molecular , Especificidade de Órgãos/genética , Poaceae/classificação , Reprodutibilidade dos Testes , Estações do Ano
9.
Fertil Steril ; 119(5): 746-750, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36925057

RESUMO

Endometriosis and adenomyosis are closely related disorders. Their pathophysiologies are extremely similar. Both tissues originate from the eutopically located intracavitary endometrium. Oligoclones of endometrial glandular epithelial cells with somatic mutations and attached stromal cells may give rise to endometriosis if they travel to peritoneal surfaces or the ovary via retrograde menstruation and/or may be entrapped in the myometrium to give rise to adenomyosis. In both instances, the endometrial cell populations possess survival and growth capabilities conferred by somatic epithelial mutations and epigenetic abnormalities in stromal cells. Activating mutations of KRAS are the most commonly found genetic variant in endometriotic epithelial cells, whereas the adenomyotic epithelial cells almost exclusively bear KRAS mutations. Epigenetic abnormalities in the stromal cells of endometriosis and adenomyosis are very similar and involve an abnormal expression pattern of nuclear receptors, including the steroid receptors. These epigenetic defects give rise to excessive local estrogen biosynthesis by aromatase and abnormal estrogen action via estrogen receptor-ß. Deficient progesterone receptor expression results in progesterone resistance in both endometriosis and adenomyosis.


Assuntos
Adenomiose , Endometriose , Doenças Uterinas , Feminino , Humanos , Endometriose/metabolismo , Adenomiose/genética , Adenomiose/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Doenças Uterinas/metabolismo , Endométrio/metabolismo , Estrogênios
10.
Nat Commun ; 11(1): 5442, 2020 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-33116128

RESUMO

Miscanthus is a perennial wild grass that is of global importance for paper production, roofing, horticultural plantings, and an emerging highly productive temperate biomass crop. We report a chromosome-scale assembly of the paleotetraploid M. sinensis genome, providing a resource for Miscanthus that links its chromosomes to the related diploid Sorghum and complex polyploid sugarcanes. The asymmetric distribution of transposons across the two homoeologous subgenomes proves Miscanthus paleo-allotetraploidy and identifies several balanced reciprocal homoeologous exchanges. Analysis of M. sinensis and M. sacchariflorus populations demonstrates extensive interspecific admixture and hybridization, and documents the origin of the highly productive triploid bioenergy crop M. × giganteus. Transcriptional profiling of leaves, stem, and rhizomes over growing seasons provides insight into rhizome development and nutrient recycling, processes critical for sustainable biomass accumulation in a perennial temperate grass. The Miscanthus genome expands the power of comparative genomics to understand traits of importance to Andropogoneae grasses.


Assuntos
Poaceae/genética , Biomassa , Cromossomos de Plantas/genética , Elementos de DNA Transponíveis , Diploide , Evolução Molecular , Regulação da Expressão Gênica de Plantas , Variação Genética , Genoma de Planta , Genômica , Modelos Genéticos , Filogenia , Poaceae/classificação , Poaceae/crescimento & desenvolvimento , Poliploidia , Saccharum/genética , Estações do Ano , Sorghum/genética
11.
Front Plant Sci ; 10: 192, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30906302

RESUMO

Herbicide safeners protect cereal crops from herbicide injury by inducing genes and proteins involved in detoxification reactions, such as glutathione S-transferases (GSTs) and cytochrome P450s (P450s). Only a few studies have characterized gene or protein expression profiles for investigating plant responses to safener treatment in cereal crops, and most transcriptome analyses in response to safener treatments have been conducted in dicot model species that are not protected by safener from herbicide injury. In this study, three different approaches were utilized in grain sorghum (Sorghum bicolor (L.) Moench) to investigate mechanisms involved in safener-regulated signaling pathways. An initial transcriptome analysis was performed to examine global gene expression in etiolated shoot tissues of hybrid grain sorghum following treatment with the sorghum safener, fluxofenim. Most upregulated transcripts encoded detoxification enzymes, including P450s, GSTs, and UDP-dependent glucosyltransferases (UGTs). Interestingly, several of these upregulated transcripts are similar to genes involved with the biosynthesis and recycling/catabolism of dhurrin, an important chemical defense compound, in these seedling tissues. Secondly, 761 diverse sorghum inbred lines were evaluated in a genome-wide association study (GWAS) to determine key molecular-genetic factors governing safener-mediated signaling mechanisms and/or herbicide detoxification. GWAS revealed a significant single nucleotide polymorphism (SNP) associated with safener-induced response on chromosome 9, located within a phi-class SbGST gene and about 15-kb from a different phi-class SbGST. Lastly, the expression of these two candidate SbGSTs was quantified in etiolated shoot tissues of sorghum inbred BTx623 in response to fluxofenim treatment. SbGSTF1 and SbGSTF2 transcripts increased within 12-hr after fluxofenim treatment but the level of safener-induced expression differed between the two genes. In addition to identifying specific GSTs potentially involved in the safener-mediated detoxification pathway, this research elucidates a new direction for studying both constitutive and inducible mechanisms for chemical defense in cereal crop seedlings.

12.
Biol Open ; 2(12): 1324-35, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24337117

RESUMO

Contrary to previous studies, we found that Xenopus laevis tadpoles raised in normoxic water without access to air can routinely complete metamorphosis with lungs that are either severely stunted and uninflated or absent altogether. This is the first demonstration that lung development in a tetrapod can be inhibited by environmental factors and that a tetrapod that relies significantly on lung respiration under unstressed conditions can be raised to forego this function without adverse effects. This study compared lung development in untreated, air-deprived (AD) and air-restored (AR) tadpoles and frogs using whole mounts, histology, BrdU labeling of cell division and antibody staining of smooth muscle actin. We also examined the relationship of swimming and breathing behaviors to lung recovery in AR animals. Inhibition and recovery of lung development occurred at the stage of lung inflation. Lung recovery in AR tadpoles occurred at a predictable and rapid rate and correlated with changes in swimming and breathing behavior. It thus presents a new experimental model for investigating the role of mechanical forces in lung development. Lung recovery in AR frogs was unpredictable and did not correlate with behavioral changes. Its low frequency of occurrence could be attributed to developmental, physical and behavioral changes, the effects of which increase with size and age. Plasticity of lung inflation at tadpole stages and loss of plasticity at postmetamorphic stages offer new insights into the role of developmental plasticity in amphibian lung loss and life history evolution.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA