RESUMO
Over the past 2 decades, fundamentals of exercise medicine, including clinical exercise testing, assessment and promotion of physical activity, exercise prescription, and supervised exercise training/rehabilitation programming have demonstrated considerable clinical value in the management of children and adolescents with congenital and acquired heart disease. Although the principles of exercise medicine have become an integral component in pediatric cardiology, there are no standardized training recommendations for exercise physiology during pediatric cardiology fellowship at this time. Thus, the Pediatric Cardiology Exercise Medicine Curriculum Committee (PCEMCC) was formed to establish core and advanced exercise physiology training recommendations for pediatric cardiology trainees. The PCEMCC includes a diverse group of pediatric cardiologists, exercise physiologists, and fellowship program directors. The expert consensus training recommendations are by no means a mandate and are summarized herein, including suggestions for achieving the minimum knowledge and training needed for general pediatric cardiology practice.
Assuntos
Cardiologia , Cardiopatias , Criança , Humanos , Adolescente , Bolsas de Estudo , Cardiologia/educação , Currículo , Exercício FísicoRESUMO
Aims In this novel study in the Irish setting, we quantified the number items managed per General Practitioner (GP) consult, how each item is managed, and impact on a GP's job satisfaction. Methods Participating GPs at two surgeries completed a questionnaire - integrated into the practice management software - after each consultation that satisfied the inclusion criteria during a four-week period. Results Due to feasibility constraints, 500 of 857 (58.3%) completed questionnaires were randomly selected for our sample. GPs manage an average of 1.76 items per consultation. Older patients presented with more items. Greater number of presenting items led to less being managed on the day 71% (n=5) for 5 items vs. 95.2% (n= 246) for 1 item, longer consultation duration (mean = 14.63 minutes (4-45) and decreased GP satisfaction, mean 8/10 (2-10). Conclusion Increasing the number of items in a GP consultation has a statistically significant effect on duration of consultation, how each item is managed, and even GP satisfaction.
Assuntos
Clínicos Gerais , Estudos Transversais , Humanos , Satisfação Pessoal , Encaminhamento e Consulta , Inquéritos e Questionários , Carga de TrabalhoRESUMO
AIM: Surgical site infection in colorectal surgery is associated with significant healthcare costs, which may be reduced by using a closed-incision negative-pressure therapy device. The aim of this study was to assess the impact of closed-incision negative-pressure therapy on the incidence of surgical site infection. METHOD: In this retrospective cohort study we evaluated all patients who had undergone high-risk open colorectal surgery at a single tertiary care centre from 2012 to 2016. We compared the incidence of surgical site infection between those receiving standard postoperative wound care between 2012 and 2014 and those receiving closed-incision negative-pressure therapy via a customizable device (Prevena Incision Management System, KCI, an Acelity company, San Antonio, Texas, USA) between 2014 and 2016. A validated surgical site infection risk score was used to create a 1:1 matched cohort subset. RESULTS: Negative pressure therapy was used in 77 patients and compared with 238 controls. Negative pressure patients were more likely to have a stoma (92% vs 48%, P < 0.01) and to be smokers (33% vs 15%, P < 0.01). Surgical site infection was higher in control patients (15%, n = 35/238) compared with negative pressure patients (7%, n = 5/77) (P = 0.05). On regression analysis, negative pressure therapy was associated with decreased surgical site infection (OR 0.27; 95% CI 0.09-0.78). These differences persisted in the matched analysis. CONCLUSION: Negative pressure therapy was associated with decreased surgical site infection. Negative pressure therapy offers significant potential for quality improvement.
Assuntos
Procedimentos Cirúrgicos do Sistema Digestório/métodos , Tratamento de Ferimentos com Pressão Negativa/métodos , Infecção da Ferida Cirúrgica/prevenção & controle , Ferida Cirúrgica/terapia , Adulto , Idoso , Estudos de Casos e Controles , Colectomia/métodos , Feminino , Humanos , Intestino Delgado/cirurgia , Laparotomia , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Protectomia/métodos , Estudos Retrospectivos , Risco , Estomas CirúrgicosRESUMO
Congenital thyroid disorders are often associated with profound deafness, indicating a requirement for thyroid hormone (T3) and its receptors in the development of hearing. Two T3 receptor genes, Tr alpha and Tr beta are differentially expressed, although in overlapping patterns, during development. Thus, the extent to which they mediate unique or redundant functions is unclear. We demonstrate that Tr beta-deficient (Thrb-/-) mice exhibit a permanent deficit in auditory function across a wide range of frequencies, although they show no other overt neurological defects. The auditory-evoked brainstem response (ABR) in Thrb-/- mice, although greatly diminished, displayed normal waveforms, which suggested that the primary defect resides in the cochlea. Although hypothyroidism causes cochlear malformation, there was no evidence of this in Thrb-/- mice. These findings suggest that Tr beta controls the maturation of auditory function but not morphogenesis of the cochlea. Thrb-/- mice provide a model for the human endocrine disorder of resistance to thyroid hormone (RTH), which is typically associated with dominant mutations in Tr beta. However, deafness is generally absent in RTH, indicating that dominant and recessive mutations in Tr beta have different consequences on the auditory system. Our results identify Tr beta as an essential transcription factor for auditory development and indicate that distinct Tr genes serve certain unique functions.
Assuntos
Surdez/genética , Receptores dos Hormônios Tireóideos/genética , Animais , Limiar Auditivo , Sequência de Bases , Cóclea/anormalidades , Cóclea/patologia , Potenciais Evocados Auditivos do Tronco Encefálico , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Homozigoto , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Camundongos Mutantes , Dados de Sequência Molecular , Mutação , FenótipoRESUMO
PURPOSE: Incisional hernia occurs in up to 20% of patients after abdominal surgery and is most common after vertical midline incisions. Diastasis recti may contribute to incisional hernia but has not been explored as a risk factor or included in hernia risk models. We examined the association between diastasis recti and incisional hernia after midline incisions. METHODS: In this single-center study, all patients undergoing elective gastrointestinal surgery with a midline open incision or extraction site in a prospective surgical quality collaborative database between 2016 and 2020 were included. Eligible patients had axial imaging within 6 months prior to surgery and no less than 6 months after surgery to determine the presence of diastasis recti and incisional hernia, respectively. Radiographic hernia-free survival was assessed with log-rank tests and multivariable Cox regression, comparing patients with and without diastasis width > 25 mm. RESULTS: Of 156 patients, forty-four (28.2%) developed radiographic hernia > 1 cm. 36 of 85 patients (42.4%) with DR width > 25 mm developed IH, compared to 9 of 71 (12.7%) without DR (p < 0.001). Hernia-free survival differed by DR width on bivariate and multivariable Cox regression, adjusted hazard ratio: 3.87, 95% confidence interval: 1.84-8.14. CONCLUSION: Diastasis recti is a significant risk factor for incisional hernia after midline abdominal surgery. When present, surgeons can include these data when discussing surgical risks and should consider a lower risk, off-midline approach when feasible. Incorporating diastasis into larger studies may improve comprehensive models of incisional hernia risk.
Assuntos
Procedimentos Cirúrgicos do Sistema Digestório , Hérnia Ventral , Hérnia Incisional , Humanos , Hérnia Incisional/cirurgia , Hérnia Ventral/cirurgia , Estudos Prospectivos , Herniorrafia/efeitos adversosRESUMO
Throughout the ongoing SARS-CoV-2 pandemic, the recommended sample type for initial diagnostic testing for SARS-CoV-2 infection has been a nasopharyngeal swab. Shortages in swabs and difficulties in obtaining nasopharyngeal swabs in certain patient groups has prompted research into alternative specimen types for the diagnosis of COVID-19. The aim of this study was to assess how 'simply collected' saliva along with tongue swabs and buccal swabs preformed as an alternative specimen type for SARS-CoV-2 detection. It was observed that saliva samples allowed for the detection of 85.3% of positive patients, tongue swabs allowed for the detection of 67.6% of positive patients and buccal swabs allowed for detection of 20.8% of positive patients, when compared to nasopharyngeal swabs. From this data, it could be concluded that using simple saliva collection can provide a less invasive and reliable alternative method for the detection of SARS-CoV2 particularly in those patients where invasive sampling is difficult and where regular repeat testing is required.
Assuntos
COVID-19 , SARS-CoV-2 , Teste para COVID-19 , Humanos , Nasofaringe , RNA Viral , Saliva , Manejo de Espécimes , LínguaAssuntos
Traumatismos Craniocerebrais/epidemiologia , Anormalidades Craniofaciais/epidemiologia , Traumatismos Faciais/epidemiologia , Hospitais Pediátricos/estatística & dados numéricos , Encaminhamento e Consulta/estatística & dados numéricos , Especialidades Cirúrgicas/estatística & dados numéricos , Distribuição por Idade , Pré-Escolar , Fissura Palatina/epidemiologia , Estudos de Coortes , Craniossinostoses/epidemiologia , Procedimentos Clínicos , Feminino , Medicina Geral , Humanos , Lactente , Irlanda , Masculino , Auditoria Médica , Neonatologia , Pediatria , Plagiocefalia/epidemiologia , Estudos RetrospectivosRESUMO
A vascular access device is defined as a catheter inserted into veins allowing fluids and medicines to be delivered intravenously1. The need for such devices in acutely unwell patients has remained steady throughout the COVID-19 pandemic. We describe here our experience of up-skilling the resident plastic surgery and maxillofacial surgical registrars to provide a vascular access service to reduce the workload on our intensive care colleagues. We hope that our practice and an 'all hands on deck' approach to the utilisation of baseline skills within the existing workforce will inform other departments to help ease the burden on critical care departments as we progress through the next stages of the COVID-19 pandemic.
Assuntos
COVID-19 , Cirurgia Plástica , Humanos , Pandemias , SARS-CoV-2 , Recursos HumanosRESUMO
Demand for beef produced from pasture-based diets is rising as it is perceived to be healthier, animal friendly and good for the environment. Animals reared on a solely grass forage diet, however, have a lower growth rate than cereal-fed animals and consequently are slaughtered at an older age. This study focused on the former by conducting life cycle assessments of beef production systems offering only fresh or conserved grass, and comparing them to a conventional pasture-based beef production system offering concentrate feeding during housing. The four suckler weanling-to-beef production systems simulated were: (i) Steers produced to slaughter entirely on a grass forage diet at 20 months (GO-20); (ii) Steers produced to slaughter entirely on a grass forage diet at 24 months (GO-24); (iii) Steers produced to slaughter on a grass forage diet with concentrate supplementation during housing (GC-24), and (iv) Steers produced to slaughter entirely on a grass forage diet at 28 months (GO-28). Two breed types were evaluated: early-maturing and late-maturing (LM). The environmental impacts assessed were global warming potential (GWP), non-renewable energy (NRE), acidification potential (AP), eutrophication potential (marine (MEP) and freshwater) were expressed per animal, per kg live weight gain (LWG), kg carcass weight gain, and kg meat weight gain (MWG). The GO-20 production system had the lowest environmental impact across all categories and functional units for both breeds. Extending age at slaughter increased environmental impact across all categories per animal. The LWG response of EM steers to concentrate feed supplementation in GC-24 was greater than the increase in total environmental impact resulting in GC-24 having a lower environmental impact across categories per kg product than GO-24. Concentrate feed supplementation had a similar effect on LM steers with the exception of NRE and AP. The increase in daily LWG in the third grazing season in comparison to the second grazing and housing resulted in GO-28 having lower GWP, NRE, AP, and MEP per kg product than GO-24. Early-maturing steers had lower environmental impact than LM when expressed per kg LWG. However the opposite occurred when impacts were expressed per kg MWG, despite LM steers producing the least LWG. The LM steers compensated for poor LWG performance by having superior carcass traits, which caused the breed to have the lowest environmental impact per kg MWG. The results reaffirms the importance of functional unit and suggests reducing the environmental impact of LWG does not always translate into improvements in the environmental performance of meat.
Assuntos
Ração Animal , Melhoramento Vegetal , Ração Animal/análise , Animais , Composição Corporal , Bovinos , Dieta/veterinária , Estágios do Ciclo de Vida , Carne/análiseRESUMO
The properties of the viral and cellular fos proteins (Fos) were investigated as a first step toward understanding the function of the fos gene. Treatment of nuclei with salt and nonionic detergents solubilized a complex that contained Fos together with several other cellular proteins. The majority of the Fos protein complex was released from isolated nuclei incubated in the presence of deoxyribonuclease I or micrococcal nuclease but not with ribonuclease A, suggesting that Fos is associated with chromatin. This hypothesis is supported by the finding that Fos protein from native or denatured nuclear extracts exhibited DNA-binding activity in vitro. These results suggest that Fos is involved in the regulation of gene expression.
Assuntos
Celulose/análogos & derivados , DNA/análogos & derivados , DNA/metabolismo , Oncogenes , Proteínas Virais/metabolismo , Neoplasias das Glândulas Suprarrenais/genética , Animais , Celulose/metabolismo , Desoxirribonuclease I/metabolismo , Eletroforese em Gel de Poliacrilamida , Nuclease do Micrococo/metabolismo , Feocromocitoma/genética , Ribonuclease Pancreático/metabolismoRESUMO
Alterations in proto-oncogene expression after stimulation of rat pheochromocytoma (PC12) cells by nerve growth factor (NGF) have been investigated. A specific stimulation of c-fos messenger RNA and protein was detected 30 minutes after treatment. This induction was enhanced more than 100-fold in the presence of peripherally active benzodiazepines. The effect was specific as very little change was observed in the levels of c-rasHa, c-rasKi, c-myc, and N-myc messenger RNA's. Under the conditions used here, NGF treatment ultimately results in neurite outgrowth, with a reduction or cessation of cell division. Thus, stimulation of the c-fos gene in this system appeared to be associated with differentiation and not with cellular proliferation. The effect of benzodiazepines was stereospecific and represents a novel action of these compounds at the level of gene expression.
Assuntos
Benzodiazepinas/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Fatores de Crescimento Neural/farmacologia , Oncogenes , Animais , Linhagem Celular , Transformação Celular Neoplásica/efeitos dos fármacos , Feocromocitoma/genética , Feocromocitoma/metabolismo , RNA Mensageiro/biossíntese , RatosRESUMO
DNA bending is essential for the assembly of multiprotein complexes that contact several DNA sequence elements. An approach based on phasing analysis was developed that allows determination of both the directed DNA bend angle and the orientation of DNA bending. This technique has been applied to the analysis of DNA bending by the transcription regulatory proteins Fos and Jun. Complexes that contained different combinations of full-length and truncated Fos and Jun induced DNA bends of different magnitudes and orientations. The DNA bends induced by the individual proteins were determined on the basis of a quantitative model for DNA bending by dimeric complexes. This information was used to visualize the consequences of DNA bending by Fos and Jun for the structures of Fos-Jun-DNA and Jun-DNA complexes.
Assuntos
Proteínas de Ligação a DNA/fisiologia , DNA/ultraestrutura , Proteínas Proto-Oncogênicas c-fos/fisiologia , Proteínas Proto-Oncogênicas c-jun/fisiologia , Gráficos por Computador , Técnicas In Vitro , Zíper de Leucina , Modelos Moleculares , Conformação de Ácido Nucleico , Peptídeos , Proteínas Proto-Oncogênicas c-fos/química , Proteínas Proto-Oncogênicas c-jun/química , Proteínas Recombinantes , Relação Estrutura-AtividadeRESUMO
The Fos and Jun oncoproteins form dimeric complexes that stimulate transcription of genes containing activator protein-1 regulatory elements. We found, by representational difference analysis, that expression of DNA 5-methylcytosine transferase (dnmt1) in fos-transformed cells is three times the expression in normal fibroblasts and that fos-transformed cells contain about 20 percent more 5-methylcytosine than normal fibroblasts. Transfection of the gene encoding Dnmt1 induced morphological transformation, whereas inhibition of dnmt1 expression or activity resulted in reversion of fos transformation. Inhibition of histone deacetylase, which associates with methylated DNA, also caused reversion. These results suggest that fos may transform cells through alterations in DNA methylation and in histone deacetylation.
Assuntos
Transformação Celular Neoplásica , DNA (Citosina-5-)-Metiltransferases/metabolismo , Genes fos , Proteínas Proto-Oncogênicas c-fos/metabolismo , 5-Metilcitosina , Acetilação , Animais , Tamanho Celular , Citosina/análogos & derivados , Citosina/metabolismo , DNA (Citosina-5-)-Metiltransferases/genética , Metilação de DNA , Inibidores Enzimáticos/farmacologia , Regulação Neoplásica da Expressão Gênica , Inibidores de Histona Desacetilases , Histonas/metabolismo , Ácidos Hidroxâmicos/farmacologia , Ratos , Transcrição Gênica , TransfecçãoRESUMO
The proto-oncogene c-fos is expressed in neurons in response to direct stimulation by growth factors and neurotransmitters. In order to determine whether the c-fos protein (Fos) and Fos-related proteins can be induced in response to polysynaptic activation, rat hindlimb motor/sensory cortex was stimulated electrically and Fos expression examined immunohistochemically. Three hours after the onset of stimulation, focal nuclear Fos staining was seen in motor and sensory thalamus, pontine nuclei, globus pallidus, and cerebellum. Moreover, 24-hour water deprivation resulted in Fos expression in paraventricular and supraoptic nuclei. Fos immunohistochemistry therefore provides a cellular method to label polysynaptically activated neurons and thereby map functional pathways.
Assuntos
Encéfalo/metabolismo , Regulação da Expressão Gênica , Proteínas Proto-Oncogênicas/genética , Animais , Núcleo Celular/metabolismo , Cerebelo/metabolismo , Córtex Cerebral/metabolismo , Estimulação Elétrica , Globo Pálido/metabolismo , Hipocampo/metabolismo , Hipotálamo/metabolismo , Imuno-Histoquímica , Córtex Motor/fisiologia , Neurônios/metabolismo , Ponte/metabolismo , Proteínas Proto-Oncogênicas c-fos , Ratos , Tálamo/metabolismoRESUMO
The proto-oncogenes c-fos and c-jun function cooperatively as inducible transcription factors in signal transduction processes. Their protein products, Fos and Jun, form a heterodimeric complex that interacts with the DNA regulatory element known as the activator protein-1 (AP-1) binding site. Dimerization occurs via interaction between leucine zipper domains and serves to bring into proper juxtaposition a region in each protein that is rich in basic amino acids and that forms a DNA-binding domain. DNA binding of the Fos-Jun heterodimer was modulated by reduction-oxidation (redox) of a single conserved cysteine residue in the DNA-binding domains of the two proteins. Furthermore, a nuclear protein was identified that reduced Fos and Jun and stimulated DNA-binding activity in vitro. These results suggest that transcriptional activity mediated by AP-1 binding factors may be regulated by a redox mechanism.
Assuntos
Proteínas de Ligação a DNA/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Fatores de Transcrição/fisiologia , Sequência de Aminoácidos , Animais , Sistema Livre de Células , Cisteína/fisiologia , Análise Mutacional de DNA , Proteínas de Ligação a DNA/efeitos dos fármacos , Diamida/farmacologia , Humanos , Técnicas In Vitro , Dados de Sequência Molecular , Oxirredução , Proteínas Proto-Oncogênicas c-fos , Proteínas Proto-Oncogênicas c-jun , Ratos , Proteínas Recombinantes , Transdução de Sinais , Relação Estrutura-Atividade , Reagentes de Sulfidrila/farmacologiaRESUMO
The protein products of the fos and jun proto-oncogenes form a heterodimeric complex that participates in a stable high affinity interaction with DNA elements containing AP-1 binding sites. The effects of deletions and point mutations in Fos and Jun on protein complex formation and DNA binding have been examined. The data suggest that Fos and Jun dimerize via a parallel interaction of helical domains containing a heptad repeat of leucine residues (the leucine zipper). Dimerization is required for DNA binding and results in the appropriate juxtaposition of basic amino acid regions from Fos and Jun, both of which are required for association with DNA.
Assuntos
Proteínas de Ligação a DNA/metabolismo , DNA/metabolismo , Leucina , Proteínas Proto-Oncogênicas/metabolismo , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Reagentes de Ligações Cruzadas , Proteínas de Ligação a DNA/genética , Glutaral , Técnicas de Imunoadsorção , Substâncias Macromoleculares , Dados de Sequência Molecular , Mutação , Conformação Proteica , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-fos , Proteínas Proto-Oncogênicas c-jun , Ratos , Sequências Repetitivas de Ácido Nucleico , Relação Estrutura-Atividade , Fatores de Transcrição/genéticaRESUMO
Glutamate and aspartate are endogenous excitatory amino acid neurotransmitters widely distributed in the mammalian central nervous system. Aspartate was shown to induce a large membrane current sensitive to N-methyl-D-aspartate (NMDA) and non-NMDA receptor antagonists in Purkinje cells from mice lacking functional NMDA receptors (NR1(-/-)). This response was accompanied by high permeability to calcium. In contrast, no current was induced by aspartate in hippocampal neurons and cerebellar granule cells from NR1(-/-) mice. Several other glutamate receptor agonists failed to evoke this response. Thus, in Purkinje cells, aspartate activates a distinct response capable of contributing to synaptic plasticity through calcium permeability.
Assuntos
Ácido Aspártico/farmacologia , Cálcio/metabolismo , Células de Purkinje/metabolismo , Receptores de Aminoácido/metabolismo , Animais , Cerebelo/citologia , Cerebelo/metabolismo , Agonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Ácido Glutâmico/farmacologia , Hipocampo/citologia , Hipocampo/metabolismo , Homocisteína/análogos & derivados , Homocisteína/farmacologia , Magnésio/farmacologia , Camundongos , Camundongos Knockout , N-Metilaspartato/farmacologia , Plasticidade Neuronal , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Técnicas de Patch-Clamp , Permeabilidade , Células de Purkinje/efeitos dos fármacos , Receptores de Aminoácido/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/agonistas , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/fisiologiaRESUMO
The Wilms' tumor locus (WTL) at 11p13 contains a gene that encodes a zinc finger-containing protein that has characteristics of a DNA-binding protein. However, binding of this protein to DNA in a sequence-specific manner has not been demonstrated. A synthetic gene was constructed that contained the zinc finger region, and the protein was expressed in Escherichia coli. The recombinant protein was used to identify a specific DNA binding site from a pool of degenerate oligonucleotides. The binding sites obtained were similar to the sequence recognized by the early growth response-1 (EGR-1) gene product, a zinc finger-containing protein that is induced by mitogenic stimuli. A mutation in the zinc finger region of the protein originally identified in a Wilms' tumor patient abolished its DNA-binding activity. These results suggest that the WTL protein may act at the DNA binding site of a growth factor-inducible gene and that loss of DNA-binding activity contributes to the tumorigenic process.
Assuntos
Proteínas de Ligação a DNA/metabolismo , DNA/metabolismo , Genes do Tumor de Wilms , Proteínas Imediatamente Precoces , Fatores de Transcrição/metabolismo , Dedos de Zinco , Sequência de Aminoácidos , Sequência de Bases , Sítios de Ligação , Ligação Competitiva , Cromossomos Humanos Par 11 , Sequência Consenso , DNA/genética , Proteínas de Ligação a DNA/genética , Proteína 1 de Resposta de Crescimento Precoce , Escherichia coli/genética , Humanos , Dados de Sequência Molecular , Mutação , Oligonucleotídeos/metabolismo , Reação em Cadeia da Polimerase , Proteínas Recombinantes/metabolismo , Mapeamento por Restrição , Fatores de Transcrição/genética , Dedos de Zinco/genéticaRESUMO
Fos and Jun form a heterodimeric complex that associates with the nucleotide sequence motif known as the AP-1 binding site. Although this complex has been proposed to function as a transcriptional regulator in neurons, no specific target gene has yet been identified. Proenkephalin mRNA increased in the hippocampus during seizure just after an increase in c-fos and c-jun expression was detected. Fos-Jun complexes bound specifically to a regulatory sequence in the 5' control region of the proenkephalin gene. Furthermore, c-fos and c-jun stimulated transcription from this control region synergistically in transactivation assays. These data suggest that the proenkephalin gene may be a physiological target for Fos and Jun in the hippocampus and indicate that these proto-oncogene transcription factors may play a role in neuronal responses to stimulation.
Assuntos
Encéfalo/metabolismo , Proteínas de Ligação a DNA/genética , Encefalinas/genética , Regulação da Expressão Gênica , Genes , Precursores de Proteínas/genética , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Proto-Oncogenes , Fatores de Transcrição/genética , Animais , Sequência de Bases , Linhagem Celular , Proteínas de Ligação a DNA/metabolismo , Elementos Facilitadores Genéticos , Hipocampo/metabolismo , Camundongos , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-fos , Proteínas Proto-Oncogênicas c-jun , RNA Mensageiro/genética , Teratoma , Fatores de Transcrição/metabolismo , Transcrição GênicaRESUMO
A dramatic and specific induction of c-fos was observed in identifiable neuronal populations in vivo after administration of the convulsant Metrazole. This effect was time- and dose-dependent and was abolished by prior treatment with the anticonvulsant drugs diazepam or pentobarbital. About 60 minutes after administration of Metrazole, c-fos messenger RNA reached a maximum and declined to basal levels after 180 minutes. A further decrease below that in normal brain was observed before a return to basal levels after 16 hours. While Metrazole still elicited seizures during this period, reinduction of c-fos was largely refractory. At 90 minutes, c-fos protein was observed in the nuclei of neurons in the dentate gyrus, and in the pyriform and cingulate cortices. Subsequently, c-fos protein appeared throughout the cortex, hippocampus, and limbic system. Thus, seizure activity results in increased c-fos gene expression in particular subsets of neurons.