Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Nat Plants ; 9(1): 81-95, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36604579

RESUMO

Stress can have long-lasting impacts on plants. Here we report the long-term effects of the stress hormone jasmonic acid (JA) on the defence phenotype, transcriptome and DNA methylome of Arabidopsis. Three weeks after transient JA signalling, 5-week-old plants retained induced resistance (IR) against herbivory but showed increased susceptibility to pathogens. Transcriptome analysis revealed long-term priming and/or upregulation of JA-dependent defence genes but repression of ethylene- and salicylic acid-dependent genes. Long-term JA-IR was associated with shifts in glucosinolate composition and required MYC2/3/4 transcription factors, RNA-directed DNA methylation, the DNA demethylase ROS1 and the small RNA (sRNA)-binding protein AGO1. Although methylome analysis did not reveal consistent changes in DNA methylation near MYC2/3/4-controlled genes, JA-treated plants were specifically enriched with hypomethylated ATREP2 transposable elements (TEs). Epigenomic characterization of mutants and transgenic lines revealed that ATREP2 TEs are regulated by RdDM and ROS1 and produce 21 nt sRNAs that bind to nuclear AGO1. Since ATREP2 TEs are enriched with sequences from IR-related defence genes, our results suggest that AGO1-associated sRNAs from hypomethylated ATREP2 TEs trans-regulate long-lasting memory of JA-dependent immunity.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Desmetilação do DNA , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Proteínas Tirosina Quinases/farmacologia , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas/farmacologia , Arabidopsis/metabolismo , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , RNA/metabolismo , Regulação da Expressão Gênica de Plantas
3.
Diabetol Metab Syndr ; 10: 2, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29308091

RESUMO

BACKGROUND: Gestational diabetes is a risk factor for future development of type 2 diabetes. The primary aim of this study was to estimate the prevalence of postpartum glucose tolerance status evaluation in pregnancies complicated by gestational diabetes 6-12 weeks after delivery. The secondary one was to identify the factors that are implicated with postpartum glucose retesting. METHODS: This was a retrospective study performed with a cohort of women with gestational diabetes, with prenatal care and delivery at a tertiary care center, from January 2013 to April 2017. The diagnosis of gestational diabetes was based on IADPSG criteria (Fasting ≥ 92 mg/dl, 1 h ≥ 180 mg/dl and/or 2 h ≥ 153 mg/dl, respectively) and the diagnosis of type 2 diabetes and prediabetes were made using the 2016 ADA's criteria (fasting and 2 h after glucose load ≥ 126 mg/dl and/or ≥ 200 and 100-125 mg/dl and/or 140 and 199 mg/dl, respectively). All women had an appointment scheduled 6-12 weeks postpartum with the results of a 75-g oral glucose tolerance test (OGTT). RESULTS: Of the 152 evaluated women, 21 (13.8%) returned with the postpartum OGTT results. Of these, 9 (45.0%) had a diagnosis of prediabetes. The use of insulin during gestation was the only factor implicated in a higher adherence rate to postpartum testing OR 6.33 (p 0.002). No significance was found for other demographic and clinical variables (age, family income, years of study, parity, gestational age at first visit, smoking, family history of type 2 diabetes, diagnosis of gestational diabetes before the third trimester, pregestational body mass index, previous history of gestational diabetes and ethnicity). CONCLUSION: The majority of patients with gestational diabetes did not return postpartum to perform OGTT and in our study the only factor implicated in a higher postpartum return was the use of insulin during pregnancy. Considering that 45.0% were diagnosed with prediabetes, diabetes care teams should initially identify non-adherent patients.

4.
Genet Mol Res ; 15(1)2016 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-26909954

RESUMO

Plasma membrane proteolipid 3 (PMP3) is a class of small hydrophobic proteins found in many organisms including higher plants. Some plant PMP3 genes have been shown to respond to abiotic stresses and to participate in the processes of plant stress tolerance. In this study, we isolated the cassava (Manihot esculenta Crantz) MePMP3-2 gene and functionally characterized its role in tolerance to abiotic stress by expressing it in rice (Oryza sativa L.). MePMP3-2 encodes a 77-amino acid protein belonging to a subgroup of plant PMP3s that have long hydrophylic C-terminal tails of unknown function. In silico analysis and co-localization studies indicated that MePMP3-2 is a plasma membrane protein with two transmembrane domains, similar to other PMP3s. In cassava leaves, MePMP3-2 expression was up-regulated by salt and drought stresses. Heterologous constitutive expression of MePMP3-2 in rice did not alter plant growth and development but increased tolerance to salt and drought stresses. In addition, under stress conditions MePMP3-2 transgenic plants accumulated less malondialdehyde, had increased levels of proline, and exhibited greater up-regulation of the stress-related genes OsProT and OsP5CS, but led to only minor changes in OsDREB2A and OsLEA3 expression. These findings indicate that MePMP3-2 may play an important role in salt and drought stress tolerance in transgenic rice.


Assuntos
Adaptação Fisiológica , Regulação da Expressão Gênica de Plantas , Manihot/fisiologia , Proteínas de Membrana/fisiologia , Oryza/fisiologia , Proteínas de Plantas/fisiologia , Plantas Geneticamente Modificadas , Sequência de Aminoácidos , Simulação por Computador , Secas , Manihot/genética , Manihot/metabolismo , Proteínas de Membrana/química , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Oryza/genética , Oryza/metabolismo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteolipídeos/fisiologia , Tolerância ao Sal , Alinhamento de Sequência , Regulação para Cima
5.
Diagn Cytopathol ; 22(4): 243-5, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10787146

RESUMO

We describe the cytological features of a malignant phyllodes tumor, in a 40-yr-old female, that metastasized to the forearm, and we correlate these findings with the criteria suggested by other authors for predicting the clinical and metastatic behavior of this tumor. The diagnosis of metastasis was based on fine-needle aspiration (FNA) cytology. One year prior, the patient had undergone mastectomy of the left breast for malignant phyllodes tumor, as proven by histopathology. The patient then presented with right forearm swelling, 1 yr later. FNA cytology was performed, and the diagnosis was metastatic malignant phyllodes tumor. Histologic review of the breast tumor revealed stromal overgrowth, which is the most important histologic criterion for predicting the metastatic behavior of malignant phyllodes tumor as reported by some authors.


Assuntos
Neoplasias da Mama/patologia , Tumor Filoide/secundário , Neoplasias de Tecidos Moles/secundário , Adulto , Biópsia por Agulha , Neoplasias da Mama/cirurgia , Feminino , Antebraço/patologia , Humanos , Mastectomia Simples , Tumor Filoide/cirurgia
6.
Eur J Biochem ; 229(2): 550-7, 1995 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-7744079

RESUMO

The sequence of the intergenic spacer (IGS) of the Brassica rapa rDNA was determined and compared with those of other Cruciferae species. In the 3012-bp IGS, two segments of mostly unique sequence flank a 1.5-kb region consisting of two tandem arrays of repeats. A putative transcription initiation site (TIS) was identified by sequence comparison, 395 bp downstream from the repeat region. The intercalating segment displays unusual sequence patterns, and modelling of its topology predicts intrinsically bent DNA, with two elements of bending centered at positions -118 and -288 relative to the TIS. Comparative analysis of spacers from Cruciferae, revealed a common organization and high sequence similarity in their 5' and, particularly, 3' regions, whereas the repeat region upstream of TIS diverges rapidly. The conservation of structural elements, including the bent DNA upstream from the TIS, is discussed in light of their possible involvement in the IGS functions and structure of spacers in common ancestors. Examination of the Cruciferae spacers shows that, in addition to unequal crossover and gene conversion, insertional mutagenesis and replication slippage are molecular mechanisms significantly contributing to their evolution.


Assuntos
Evolução Biológica , Brassica/genética , DNA Ribossômico/genética , Genes de Plantas , Sequência de Bases , Dados de Sequência Molecular , Sequências Repetitivas de Ácido Nucleico , Mapeamento por Restrição , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico
7.
Plant Mol Biol ; 26(3): 817-32, 1994 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7999997

RESUMO

Canrep is a heterogeneous, tandemly repeated, 176 bp nucleotide sequence that contains a single Hind III site and is present in high copy numbers in the genomes of many Brassica species. Complete clusters of repeats of this DNA were cloned from the nuclear DNA of Brassica juncea. Restriction-fragment dimers and higher multimers of the 176 bp sequence have arisen by mutations within the Hind III recognition sequence. Adjacent repeats from within the same cluster usually have different nucleotide sequences with features indicating that diversity is generated by a mechanism that causes site-specific base substitutions. While most of the units of canrep DNA are clustered in long arrays of tandem repeats, some are dispersed throughout the genome as isolated copies or in small clusters. Regardless of the size of the arrays, each cluster begins and ends with a variable-length, truncated repeat and is flanked by inverted copies of the sequence 5'-ATCTCAT3'-, which is not part of the basic sequence of the canrep family of DNAs. Furthermore, some clusters are located close to nucleotide sequences related to those of known plant transposons. Thus, canrep elements may be dispersed by transposition. There are two distinct subfamilies of canrep sequences in B. juncea, and one of these is closely related to one of the two subfamilies of this type of DNA from B. napus, indicating that it originated from B. campestris, the common diploid ancestor of both amphidiploid species. Neither the repetitive DNA nor nucleotide sequences flanking canrep clusters are transcribed in seedlings, suggesting that even small arrays of repeats are located in heterochromatic regions and might be involved in chromatin condensation and/or chromosome segregation.


Assuntos
Brassica/genética , DNA de Plantas/genética , Genoma de Planta , Sequências Repetitivas de Ácido Nucleico/genética , Sequência de Bases , Clonagem Molecular , Variação Genética/genética , Biblioteca Genômica , Dados de Sequência Molecular , Mapeamento por Restrição , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico , Transcrição Gênica
8.
Acta Med Port ; 6(11): 543-6, 1993 Nov.
Artigo em Português | MEDLINE | ID: mdl-8140923

RESUMO

We present the case of an HIV-seropositive drug addict patient whose seropositivity was unknown until admission to hospital, where he presented with a clinical picture of fever splenomegaly and weight loss. A diagnosis of visceral leishmaniasis was established. We stress the diagnostic difficulties well expressed in the need to repeat the bone marrow aspirate to detect the presence of leishmanias. The lack of response to conventional antimonial therapy is discussed as well as the role of pentamidine as an alternative therapy.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Soropositividade para HIV/diagnóstico , HIV-1/imunologia , Leishmaniose Visceral/diagnóstico , Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Adulto , Animais , Quimioterapia Combinada , Febre/diagnóstico , Soropositividade para HIV/tratamento farmacológico , Hepatomegalia/diagnóstico , Dependência de Heroína/complicações , Humanos , Leishmania donovani/isolamento & purificação , Leishmaniose Visceral/tratamento farmacológico , Masculino , Esplenomegalia/diagnóstico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...