Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Anaesthesiologie ; 72(12): 871-877, 2023 12.
Artigo em Alemão | MEDLINE | ID: mdl-37999740

RESUMO

Resuscitative endovascular balloon occlusion of the aorta (REBOA) represents an endovascular procedure for aortic occlusion. The procedure can be used for temporary hemorrhage control as a bridge until surgical treatment for noncompressible abdominal or pelvic bleeding and to improve coronary and cerebral perfusion pressure during cardiopulmonary resuscitation. The prehospital administration is challenging and currently hardly possible in Germany. In the REBOA in bleeding and cardiac arrest in the prehospital care by helicopter emergency medical service (RIBCAP-HEMS) project, the prehospital use of REBOA will be tested in a feasibility study. This article describes the training course on the procedure in preparation for prehospital use, which was conducted before the start of the aforementioned feasibility study for the emergency physicians and paramedics (HEMS-TC) of the DRF Air Rescue Base in Halle (Saale). The course provided the necessary theoretical and practical skills to apply REBOA in the prehospital setting to patients in extremis in a safe, indications-conform and time-critical manner. The fact that all emergency physicians of the two air ambulances Christoph 84 and Christoph 85 in Halle are specialists in anesthesiology with corresponding experience in the placement of invasive arterial catheters proved to be advantageous. The training course was able to significantly improve the theoretical and practical abilities of the participants. The results of the currently ongoing study must show whether the procedure can be usefully integrated into the prehospital care of patients in extremis.


Assuntos
Oclusão com Balão , Reanimação Cardiopulmonar , Serviços Médicos de Emergência , Humanos , Aorta/cirurgia , Hemorragia/terapia , Serviços Médicos de Emergência/métodos , Oclusão com Balão/métodos
2.
J Clin Med ; 12(7)2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-37048553

RESUMO

During the COVID-19 pandemic, large numbers of elderly, multimorbid people required treatment in intensive care units. This study investigated how the inherent patient factors age and comorbidity burden affected the treatment strategy and the outcome achieved. Retrospective analysis of data from intensive care patients enrolled in the Lean European Open Survey on SARS-CoV2-Infected Patients (LEOSS) cohort found that a patient's age and comorbidity burden in fact influenced their mortality rate and the use of ventilation therapy. Evidence showed that advanced age and multimorbidity were associated with the restrictive use of invasive ventilation therapies, particularly ECMO. Geriatric patients with a high comorbidity burden were clustered in the sub-cohort of non-ventilated ICU patients characterized by a high mortality rate. The risk of death generally increased with older age and accumulating comorbidity burden. Here, the more aggressive an applied procedure, the younger the age in which a majority of patients died. Clearly, geriatric, multimorbid COVID-19 patients benefit less from invasive ventilation therapies. This implies the need for a holistic approach to therapy decisions, taking into account the patient's wishes.

3.
J Clin Med ; 11(17)2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-36079168

RESUMO

Superinfections are a fundamental critical care problem, and their significance in severe COVID-19 cases needs to be determined. This study analyzed data from the Lean European Open Survey on SARS-CoV-2-Infected Patients (LEOSS) cohort focusing on intensive care patients. A retrospective analysis of patient data from 840 cases of COVID-19 with critical courses demonstrated that co-infections were frequently present and were primarily of nosocomial origin. Furthermore, our analysis showed that invasive therapy procedures accompanied an increased risk for healthcare-associated infections. Non-ventilated ICU patients were rarely affected by secondary infections. The risk of infection, however, increased even when non-invasive ventilation was used. A further, significant increase in infection rates was seen with the use of invasive ventilation and even more so with extracorporeal membrane oxygenation (ECMO) therapy. The marked differences among ICU techniques used for the treatment of COVID-19-induced respiratory failure in terms of secondary infection risk profile should be taken into account for the optimal management of critically ill COVID-19 patients, as well as for adequate antimicrobial therapy.

4.
Anaesthesiologie ; 71(10): 767-773, 2022 10.
Artigo em Alemão | MEDLINE | ID: mdl-35925195

RESUMO

INTRODUCTION: As part of surgical interventions in pediatric patients, children with craniofacial malformations and syndromes are presented in the field of oral and maxillofacial surgery, anesthesia and also in all other clinical disciplines. In particular, the Pierre Robin sequence in the clinical context leads to a situation albeit a rare one, which should be given high attention in preoperative, intraoperative and postoperative care. MATERIAL AND METHODS: In a retrospective analysis from 1993 to 2020 in the Department of Oral and Maxillofacial Surgery at the University Hospital Halle (Saale), a total of 54 patients were identified with syndromic changes and a need for surgical treatment. During this period, 12 patients with a Pierre Robin sequence were genetically confirmed, who received a total of 20 surgical interventions under general anesthesia at different times. Statistical analysis was performed using SPSS 17.0. RESULTS: In 12 patients with a Pierre Robin sequence, 20 surgical procedures were performed with the patient under general anesthesia. The youngest patients had an average age of 6 months, the oldest 16 years at the time of the operation. The average age was 5.7 years. In addition to the genetic component, all children were assigned to the ASA I classification. The surgical indication was initially an isolated cleft palate in all patients, followed by further interventions such as dental restorations, corrective surgery in the area of the palate or ear nose throat (ENT) examinations. Drug induction of general anesthesia was weight-adapted using propofol 1%, fentanyl or remifentanil and rocuronium. In our study, out of 18 orotracheal intubations, only 2 patients had to be intubated by video laryngoscopy. One patient required nasal intubation and another was fitted with a laryngeal mask. The success rate of conventional intubation was 89.5%. Postoperatively, one infant had recurrent drops in saturation, so that reintubation was necessary.


Assuntos
Máscaras Laríngeas , Síndrome de Pierre Robin , Propofol , Anestesia Geral/efeitos adversos , Criança , Pré-Escolar , Fentanila , Hospitais Universitários , Humanos , Lactente , Síndrome de Pierre Robin/genética , Remifentanil , Estudos Retrospectivos , Rocurônio
5.
HNO ; 70(10): 765-768, 2022 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-35362726

RESUMO

HISTORY: A 21-year-old female was injured by accidental strangulation. Dyspnea and stridor occurred with delay, and led to emergency intubation. FINDINGS: Physical examination showed strangulation marks and neck emphysema. Computed tomography confirmed laryngotracheal separation and revealed misplacement of the ventilation tube. DIAGNOSIS: Further surgical exploration revealed complete laryngotracheal (cricotracheal) separation. TREATMENT: After initial emergency tracheotomy, cricotracheal reanastomosis was achieved by a two-stage surgical approach. CONCLUSION: Laryngotracheal separation is associated with high mortality. In the case presented herein, the patient survived and was discharged from hospital without a tracheostomy tube despite bilateral recurrent laryngeal nerve palsy.


Assuntos
Traqueia , Traqueotomia , Adulto , Feminino , Humanos , Pescoço , Tomografia Computadorizada por Raios X , Traqueia/diagnóstico por imagem , Traqueia/cirurgia , Traqueostomia , Adulto Jovem
6.
BMC Cardiovasc Disord ; 21(1): 528, 2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34743690

RESUMO

BACKGROUND: The value of mechanical circulatory support (MCS) in cardiogenic shock, especially the combination of the ECMELLA approach (Impella combined with ECMO), remains controversial. CASE PRESENTATION: A previously healthy 33-year-old female patient was submitted to a local emergency department with a flu-like infection and febrile temperatures up to 39 °C. The patient was tested positive for type-A influenza, however negative for SARS-CoV-2. Despite escalated invasive ventilation, refractory hypercapnia (paCO2: 22 kPa) with severe respiratory acidosis (pH: 6.9) and a rising norepinephrine rate occurred within a few hours. Due to a Horovitz-Index < 100, out-of-centre veno-venous extracorporeal membrane oxygenation (vv-ECMO)-implantation was performed. A CT-scan done because of anisocoria revealed an extended dissection of the right vertebral artery. While the initial left ventricular function was normal, echocardiography revealed severe global hypokinesia. After angiographic exclusion of coronary artery stenoses, we geared up LV unloading by additional implantation of an Impella CP and expanded the vv-ECMO to a veno-venous-arterial ECMO (vva-ECMO). Clinically relevant bleeding from the punctured femoral arteries resulted in massive transfusion and was treated by vascular surgery later on. Under continued MCS, LVEF increased to approximately 40% 2 days after the initiation of ECMELLA. After weaning, the Impella CP was explanted at day 5 and the vva-ECMO was removed on day 9, respectively. The patient was discharged in an unaffected neurological condition to rehabilitation 25 days after the initial admission. CONCLUSIONS: This exceptional case exemplifies the importance of aggressive MCS in severe cardiogenic shock, which may be especially promising in younger patients with non-ischaemic cardiomyopathy and potentially reversible causes of cardiogenic shock. This case impressively demonstrates that especially young patients may achieve complete neurological restoration, even though the initial prognosis may appear unfavourable.


Assuntos
Oxigenação por Membrana Extracorpórea/métodos , Coração Auxiliar , Vírus da Influenza A/isolamento & purificação , Influenza Humana , Respiração Artificial/métodos , Insuficiência Respiratória , Disfunção Ventricular Esquerda , Adulto , COVID-19/diagnóstico , Deterioração Clínica , Cuidados Críticos/métodos , Ecocardiografia/métodos , Feminino , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Humanos , Influenza Humana/complicações , Influenza Humana/diagnóstico , Influenza Humana/fisiopatologia , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/fisiopatologia , Insuficiência Respiratória/terapia , SARS-CoV-2 , Testes Sorológicos/métodos , Índice de Gravidade de Doença , Choque Cardiogênico/etiologia , Choque Cardiogênico/fisiopatologia , Choque Cardiogênico/terapia , Resultado do Tratamento , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/fisiopatologia , Disfunção Ventricular Esquerda/terapia
7.
Nat Plants ; 5(1): 54-62, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30598532

RESUMO

Domesticated plants and animals often display dramatic responses to selection, but the origins of the genetic diversity underlying these responses remain poorly understood. Despite domestication and improvement bottlenecks, the cultivated sunflower remains highly variable genetically, possibly due to hybridization with wild relatives. To characterize genetic diversity in the sunflower and to quantify contributions from wild relatives, we sequenced 287 cultivated lines, 17 Native American landraces and 189 wild accessions representing 11 compatible wild species. Cultivar sequences failing to map to the sunflower reference were assembled de novo for each genotype to determine the gene repertoire, or 'pan-genome', of the cultivated sunflower. Assembled genes were then compared to the wild species to estimate origins. Results indicate that the cultivated sunflower pan-genome comprises 61,205 genes, of which 27% vary across genotypes. Approximately 10% of the cultivated sunflower pan-genome is derived through introgression from wild sunflower species, and 1.5% of genes originated solely through introgression. Gene ontology functional analyses further indicate that genes associated with biotic resistance are over-represented among introgressed regions, an observation consistent with breeding records. Analyses of allelic variation associated with downy mildew resistance provide an example in which such introgressions have contributed to resistance to a globally challenging disease.


Assuntos
Helianthus/genética , Helianthus/microbiologia , Hibridização Genética , Doenças das Plantas/genética , Produtos Agrícolas/genética , Produtos Agrícolas/microbiologia , Resistência à Doença/genética , Ontologia Genética , Genes de Plantas , Variação Genética , Genoma de Planta , Doenças das Plantas/microbiologia , Recombinação Genética , Seleção Genética
8.
PLoS One ; 12(5): e0178163, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28542423

RESUMO

Genetic manipulation of the deadly malaria parasite Plasmodium falciparum remains challenging, but the rise of CRISPR/Cas9-based genome editing tools is increasing the feasibility of altering this parasite's genome in order to study its biology. Of particular interest is the investigation of drug targets and drug resistance mechanisms, which have major implications for fighting malaria. We present a new method for introducing drug resistance mutations in P. falciparum without the use of plasmids or the need for cloning homologous recombination templates. We demonstrate this method by introducing edits into the sodium efflux channel PfATP4 by transfection of a purified CRISPR/Cas9-guide RNA ribonucleoprotein complex and a 200-nucleotide single-stranded oligodeoxynucleotide (ssODN) repair template. Analysis of whole genome sequencing data with the variant-finding program MinorityReport confirmed that only the intended edits were made, and growth inhibition assays confirmed that these mutations confer resistance to the antimalarial SJ733. The method described here is ideally suited for the introduction of mutations that confer a fitness advantage under selection conditions, and the novel finding that an ssODN can function as a repair template in P. falciparum could greatly simplify future editing attempts regardless of the nuclease used or the delivery method.


Assuntos
Sistemas CRISPR-Cas/genética , Resistência a Medicamentos/genética , Genoma de Protozoário , ATPase Trocadora de Hidrogênio-Potássio/genética , Isoquinolinas/farmacologia , Mutação/genética , Plasmodium falciparum/genética , Sequência de Aminoácidos , Sequência de Bases , Vetores Genéticos , Humanos , Malária Falciparum/genética , Malária Falciparum/parasitologia , Plasmídeos , Edição de RNA/genética
9.
Genome Announc ; 4(5)2016 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-27635002

RESUMO

This is the first complete mitochondrial genome sequence for sunflower and the first complete mitochondrial genome for any member of Asteraceae, the largest plant family, which includes over 23,000 named species. The master circle is 300,945-bp long and includes 27 protein-coding sequences, 18 tRNAs, and the 26S, 5S, and 18S rRNAs.

10.
J Colloid Interface Sci ; 481: 82-90, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-27454031

RESUMO

Surfaces that simultaneously exhibit superhydrophobicity, low contact angle hysteresis, and high transmission of visible light are of interest for many applications, such as optical devices, solar panels, and self-cleaning windows. Superhydrophobicity could also find use in medical devices where antifouling characteristics are desirable. These applications also typically require mechanical wear resistance. The fabrication of such surfaces is challenging due to the competing goals of superhydrophobicity and transmittance in terms of the required degree of surface roughness. In this study, deep reactive ion etching (DRIE) was used to create rough surfaces on PDMS substrates using a O2/CF4 plasma. Surfaces then underwent an additional treatment with either octafluorocyclobutane (C4F8) plasma or vapor deposition of perfluorooctyltrichlorosilane (PFOTCS) following surface activation with O2 plasma. The effects of surface roughness and the additional surface modifications were examined with respect to the contact angle, contact angle hysteresis, and optical transmittance. To examine wear resistance, a sliding wear experiment was performed using an atomic force microscope (AFM).

11.
BMC Plant Biol ; 15: 84, 2015 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-25887675

RESUMO

BACKGROUND: Shoot branching is an important determinant of plant architecture and influences various aspects of growth and development. Selection on branching has also played an important role in the domestication of crop plants, including sunflower (Helianthus annuus L.). Here, we describe an investigation of the genetic basis of variation in branching in sunflower via association mapping in a diverse collection of cultivated sunflower lines. RESULTS: Detailed phenotypic analyses revealed extensive variation in the extent and type of branching within the focal population. After correcting for population structure and kinship, association analyses were performed using a genome-wide collection of SNPs to identify genomic regions that influence a variety of branching-related traits. This work resulted in the identification of multiple previously unidentified genomic regions that contribute to variation in branching. Genomic regions that were associated with apical and mid-apical branching were generally distinct from those associated with basal and mid-basal branching. Homologs of known branching genes from other study systems (i.e., Arabidopsis, rice, pea, and petunia) were also identified from the draft assembly of the sunflower genome and their map positions were compared to those of associations identified herein. Numerous candidate branching genes were found to map in close proximity to significant branching associations. CONCLUSIONS: In sunflower, variation in branching is genetically complex and overall branching patterns (i.e., apical vs. basal) were found to be influenced by distinct genomic regions. Moreover, numerous candidate branching genes mapped in close proximity to significant branching associations. Although the sunflower genome exhibits localized islands of elevated linkage disequilibrium (LD), these non-random associations are known to decay rapidly elsewhere. The subset of candidate genes that co-localized with significant associations in regions of low LD represents the most promising target for future functional analyses.


Assuntos
Helianthus/crescimento & desenvolvimento , Helianthus/genética , Genes de Plantas , Polimorfismo de Nucleotídeo Único
12.
Nature ; 522(7554): 89-93, 2015 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-25762136

RESUMO

Disruption of the MECP2 gene leads to Rett syndrome (RTT), a severe neurological disorder with features of autism. MECP2 encodes a methyl-DNA-binding protein that has been proposed to function as a transcriptional repressor, but despite numerous mouse studies examining neuronal gene expression in Mecp2 mutants, no clear model has emerged for how MeCP2 protein regulates transcription. Here we identify a genome-wide length-dependent increase in gene expression in MeCP2 mutant mouse models and human RTT brains. We present evidence that MeCP2 represses gene expression by binding to methylated CA sites within long genes, and that in neurons lacking MeCP2, decreasing the expression of long genes attenuates RTT-associated cellular deficits. In addition, we find that long genes as a population are enriched for neuronal functions and selectively expressed in the brain. These findings suggest that mutations in MeCP2 may cause neurological dysfunction by specifically disrupting long gene expression in the brain.


Assuntos
Metilação de DNA/genética , Proteína 2 de Ligação a Metil-CpG/genética , Proteína 2 de Ligação a Metil-CpG/metabolismo , Mutação/genética , Síndrome de Rett/genética , Animais , Sequência de Bases , Encéfalo/metabolismo , DNA (Citosina-5-)-Metiltransferases/metabolismo , DNA Metiltransferase 3A , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Proteína 2 de Ligação a Metil-CpG/deficiência , Camundongos , Dados de Sequência Molecular , Neurônios/metabolismo
13.
J Org Chem ; 80(3): 1312-20, 2015 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-25584395

RESUMO

Despite significant advances in antimalarial chemotherapy over the past 30 years, development of resistance to frontline drugs remains a significant challenge that limits efforts to eradicate the disease. We now report the discovery of a new class of antimalarials, salinipostins A-K, with low nanomolar potencies and high selectivity indices against mammalian cells (salinipostin A: Plasmodium falciparum EC50 50 nM, HEK293T cytotoxicity EC50 > 50 µM). These compounds were isolated from a marine-derived Salinospora sp. bacterium and contain a bicyclic phosphotriester core structure, which is a rare motif among natural products. This scaffold differs significantly from the structures of known antimalarial compounds and represents a new lead structure for the development of therapeutic targets in malaria. Examination of the growth stage specificity of salinipostin A indicates that it exhibits growth stage-specific effects that differ from compounds that inhibit heme polymerization, while resistance selection experiments were unable to identify parasite populations that exhibited significant resistance against this compound class.


Assuntos
Antimaláricos/química , Antimaláricos/farmacologia , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/química , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Compostos Bicíclicos com Pontes/química , Compostos Bicíclicos com Pontes/farmacologia , Células HEK293/química , Malária/metabolismo , Plasmodium falciparum/efeitos dos fármacos , Animais , Produtos Biológicos/isolamento & purificação , Compostos Bicíclicos com Pontes/isolamento & purificação , Compostos Bicíclicos Heterocíclicos com Pontes/isolamento & purificação , Humanos , Biologia Marinha , Plasmodium falciparum/química
14.
Proc Natl Acad Sci U S A ; 111(50): E5455-62, 2014 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-25453091

RESUMO

Drug discovery for malaria has been transformed in the last 5 years by the discovery of many new lead compounds identified by phenotypic screening. The process of developing these compounds as drug leads and studying the cellular responses they induce is revealing new targets that regulate key processes in the Plasmodium parasites that cause malaria. We disclose herein that the clinical candidate (+)-SJ733 acts upon one of these targets, ATP4. ATP4 is thought to be a cation-transporting ATPase responsible for maintaining low intracellular Na(+) levels in the parasite. Treatment of parasitized erythrocytes with (+)-SJ733 in vitro caused a rapid perturbation of Na(+) homeostasis in the parasite. This perturbation was followed by profound physical changes in the infected cells, including increased membrane rigidity and externalization of phosphatidylserine, consistent with eryptosis (erythrocyte suicide) or senescence. These changes are proposed to underpin the rapid (+)-SJ733-induced clearance of parasites seen in vivo. Plasmodium falciparum ATPase 4 (pfatp4) mutations that confer resistance to (+)-SJ733 carry a high fitness cost. The speed with which (+)-SJ733 kills parasites and the high fitness cost associated with resistance-conferring mutations appear to slow and suppress the selection of highly drug-resistant mutants in vivo. Together, our data suggest that inhibitors of PfATP4 have highly attractive features for fast-acting antimalarials to be used in the global eradication campaign.


Assuntos
Antimaláricos/farmacologia , ATPases Transportadoras de Cálcio/metabolismo , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Isoquinolinas/farmacologia , Malária/tratamento farmacológico , Modelos Moleculares , Plasmodium/efeitos dos fármacos , Antimaláricos/farmacocinética , ATPases Transportadoras de Cálcio/genética , Senescência Celular/efeitos dos fármacos , Descoberta de Drogas , Resistência a Medicamentos/genética , Eritrócitos/efeitos dos fármacos , Citometria de Fluxo , Compostos Heterocíclicos de 4 ou mais Anéis/farmacocinética , Ensaios de Triagem em Larga Escala , Isoquinolinas/farmacocinética , Estrutura Molecular
15.
New Phytol ; 201(3): 1021-1030, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24245977

RESUMO

The perennial sunflower Helianthus tuberosus, known as Jerusalem Artichoke or Sunchoke, was cultivated in eastern North America before European contact. As such, it represents one of the few taxa that can support an independent origin of domestication in this region. Its tubers were adopted as a source of food and forage when the species was transferred to the Old World in the early 1600s, and are still used today. Despite the cultural and economic importance of this tuber crop species, its origin is debated. Competing hypotheses implicate the occurrence of polyploidization with or without hybridization, and list the annual sunflower H. annuus and five distantly related perennial sunflower species as potential parents. Here, we test these scenarios by skimming the genomes of diverse populations of Jerusalem Artichoke and its putative progenitors. We identify relationships among Helianthus taxa using complete plastomes (151 551 bp), partial mitochondrial genomes (196 853 bp) and 35S (8196 bp) and 5S (514 bp) ribosomal DNA. Our results refute the possibility that Jerusalem Artichoke is of H. annuus ancestry. We provide the first genetic evidence that this species originated recursively from perennial sunflowers of central-eastern North America via hybridization between tetraploid Hairy Sunflower and diploid Sawtooth Sunflower.


Assuntos
Evolução Biológica , Produtos Agrícolas/genética , Genoma de Planta/genética , Helianthus/genética , Tubérculos/genética , DNA Ribossômico/genética , Geografia , Haplótipos/genética , Funções Verossimilhança , Filogenia , Polimorfismo Genético
16.
Nat Neurosci ; 16(7): 898-902, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23770565

RESUMO

Rett syndrome (RTT) is a severe neurological disorder that is caused by mutations in the MECP2 gene. Many missense mutations causing RTT are clustered in the DNA-binding domain of MeCP2, suggesting that association with chromatin is critical for its function. We identified a second mutational cluster in a previously uncharacterized region of MeCP2. We found that RTT mutations in this region abolished the interaction between MeCP2 and the NCoR/SMRT co-repressor complexes. Mice bearing a common missense RTT mutation in this domain exhibited severe RTT-like phenotypes. Our data are compatible with the hypothesis that brain dysfunction in RTT is caused by a loss of the MeCP2 'bridge' between the NCoR/SMRT co-repressors and chromatin.


Assuntos
Proteína 2 de Ligação a Metil-CpG/genética , Mutação/genética , Correpressor 1 de Receptor Nuclear/metabolismo , Correpressor 2 de Receptor Nuclear/metabolismo , Síndrome de Rett/genética , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Células Cultivadas , Modelos Animais de Doenças , Comportamento Exploratório/fisiologia , Proteínas de Fluorescência Verde/genética , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Imunoprecipitação , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Moleculares , Correpressor 1 de Receptor Nuclear/genética , Correpressor 2 de Receptor Nuclear/genética , Síndrome de Rett/patologia , Síndrome de Rett/fisiopatologia
17.
Nature ; 499(7458): 341-5, 2013 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-23770587

RESUMO

Rett syndrome (RTT) is an X-linked human neurodevelopmental disorder with features of autism and severe neurological dysfunction in females. RTT is caused by mutations in methyl-CpG-binding protein 2 (MeCP2), a nuclear protein that, in neurons, regulates transcription, is expressed at high levels similar to that of histones, and binds to methylated cytosines broadly across the genome. By phosphotryptic mapping, we identify three sites (S86, S274 and T308) of activity-dependent MeCP2 phosphorylation. Phosphorylation of these sites is differentially induced by neuronal activity, brain-derived neurotrophic factor, or agents that elevate the intracellular level of 3',5'-cyclic AMP (cAMP), indicating that MeCP2 may function as an epigenetic regulator of gene expression that integrates diverse signals from the environment. Here we show that the phosphorylation of T308 blocks the interaction of the repressor domain of MeCP2 with the nuclear receptor co-repressor (NCoR) complex and suppresses the ability of MeCP2 to repress transcription. In knock-in mice bearing the common human RTT missense mutation R306C, neuronal activity fails to induce MeCP2 T308 phosphorylation, suggesting that the loss of T308 phosphorylation might contribute to RTT. Consistent with this possibility, the mutation of MeCP2 T308A in mice leads to a decrease in the induction of a subset of activity-regulated genes and to RTT-like symptoms. These findings indicate that the activity-dependent phosphorylation of MeCP2 at T308 regulates the interaction of MeCP2 with the NCoR complex, and that RTT in humans may be due, in part, to the loss of activity-dependent MeCP2 T308 phosphorylation and a disruption of the phosphorylation-regulated interaction of MeCP2 with the NCoR complex.


Assuntos
Proteínas Correpressoras/metabolismo , Proteína 2 de Ligação a Metil-CpG/metabolismo , Treonina/metabolismo , Animais , Células Cultivadas , Humanos , Proteína 2 de Ligação a Metil-CpG/química , Proteína 2 de Ligação a Metil-CpG/genética , Camundongos , Mutação , Neurônios/metabolismo , Fosforilação , Síndrome de Rett/genética , Transcrição Gênica
18.
PLoS Genet ; 9(3): e1003378, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23555290

RESUMO

The combination of large-scale population genomic analyses and trait-based mapping approaches has the potential to provide novel insights into the evolutionary history and genome organization of crop plants. Here, we describe the detailed genotypic and phenotypic analysis of a sunflower (Helianthus annuus L.) association mapping population that captures nearly 90% of the allelic diversity present within the cultivated sunflower germplasm collection. We used these data to characterize overall patterns of genomic diversity and to perform association analyses on plant architecture (i.e., branching) and flowering time, successfully identifying numerous associations underlying these agronomically and evolutionarily important traits. Overall, we found variable levels of linkage disequilibrium (LD) across the genome. In general, islands of elevated LD correspond to genomic regions underlying traits that are known to have been targeted by selection during the evolution of cultivated sunflower. In many cases, these regions also showed significantly elevated levels of differentiation between the two major sunflower breeding groups, consistent with the occurrence of divergence due to strong selection. One of these regions, which harbors a major branching locus, spans a surprisingly long genetic interval (ca. 25 cM), indicating the occurrence of an extended selective sweep in an otherwise recombinogenic interval.


Assuntos
Variação Genética , Helianthus/genética , Locos de Características Quantitativas/genética , Seleção Genética , Mapeamento Cromossômico , Estudos de Associação Genética , Genoma de Planta , Humanos , Desequilíbrio de Ligação , Filogenia
19.
Nature ; 493(7432): 327-37, 2013 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-23325215

RESUMO

Neuronal activity induces the post-translational modification of synaptic molecules, promotes localized protein synthesis within dendrites and activates gene transcription, thereby regulating synaptic function and allowing neuronal circuits to respond dynamically to experience. Evidence indicates that many of the genes that are mutated in autism spectrum disorder are crucial components of the activity-dependent signalling networks that regulate synapse development and plasticity. Dysregulation of activity-dependent signalling pathways in neurons may, therefore, have a key role in the aetiology of autism spectrum disorder.


Assuntos
Transtornos Globais do Desenvolvimento Infantil/patologia , Transtornos Globais do Desenvolvimento Infantil/fisiopatologia , Neurônios/fisiologia , Transdução de Sinais , Criança , Transtornos Globais do Desenvolvimento Infantil/genética , Regulação da Expressão Gênica , Humanos , Plasticidade Neuronal , Sinapses/metabolismo
20.
Langmuir ; 28(31): 11391-9, 2012 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-22765167

RESUMO

It is of significant interest to create surfaces that simultaneously exhibit high water contact angle, low contact angle hysteresis, and high transmission of visible light, as well as mechanical wear resistance for industrial applications. The fabrication of such surfaces has often involved complex or expensive processes, required techniques that were not suitable for a variety of substrates and particles, required surface post-treatment, or lacked wear resistance. A systematic study has been performed in which transparent superhydrophobic surfaces were created on glass, polycarbonate, and poly(methyl methacrylate) (PMMA) substrates using surface-functionalized SiO(2), ZnO, and indium tin oxide (ITO) nanoparticles. The contact angle, contact angle hysteresis, and optical transmittance were measured for samples using all particle-substrate combinations. To examine wear resistance, multiscale wear experiments were performed using an atomic force microscope (AFM) and a water jet apparatus.


Assuntos
Nanopartículas/química , Dióxido de Silício/química , Compostos de Estanho/química , Óxido de Zinco/química , Vidro/química , Interações Hidrofóbicas e Hidrofílicas , Teste de Materiais , Microscopia de Força Atômica , Nanopartículas/ultraestrutura , Cimento de Policarboxilato/química , Polímeros/química , Polimetil Metacrilato/química , Propriedades de Superfície , Água
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...