Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 52
Filtrar
1.
Occup Med (Lond) ; 73(2): 109-111, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36097691

RESUMO

The antioxidant, tert-butylhydroquinone (TBHQ), a common additive in food and cosmetics can cause allergic contact dermatitis. A 49-year-old non-atopic male factory worker developed asthma in connection with cleaning mixing drums containing TBHQ. Due to the suspicion that TBHQ might be the cause of asthma, a specific inhalation challenge was carried out. Lactose was used as a control agent. The following day he developed asthma symptoms with a 41% drop in FEV1 after 30-min exposure to small amounts of TBHQ and water. Methacholine reactivity increased 5-fold after TBHQ exposure compared to pre-exposure reactivity. This suggests that TBHQ may be the cause of asthma in this case. Due to this case respirators were introduced in the factory to reduce TBHQ exposure. TBHQ has not previously been shown to cause asthma.


Assuntos
Antioxidantes , Hidroquinonas , Masculino , Humanos , Pessoa de Meia-Idade , Antioxidantes/efeitos adversos , Hidroquinonas/efeitos adversos
2.
Eur J Neurol ; 26(12): 1426-1432, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31002206

RESUMO

BACKGROUND AND PURPOSE: Neuroinflammation has been proposed as part of the pathogenesis of post-concussion symptoms (PCS), but the inflammatory response of the human brain to mild traumatic brain injury (mTBI) remains unknown. We hypothesized that a neuroinflammatory response is present in mTBI at 1-2 weeks post-injury and persists in patients with PCS. METHODS: We scanned 14 patients with mTBI without signs of structural damage at 1-2 weeks and 3-4 months post-injury and 22 healthy controls once using the single photon emission computed tomography tracer 123 I-CLINDE, which visualizes translocator protein (TSPO), a protein upregulated in active immune cells. PCS was defined as three or more persisting symptoms from the Rivermead Post Concussion Symptoms Questionnaire at 3 months post-injury. RESULTS: Across brain regions, patients had significantly higher 123 I-CLINDE binding to TSPO than healthy controls, both at 1-2 weeks after the injury in all patients (P = 0.011) and at 3-4 months in the seven patients with PCS (P = 0.006) and in the six patients with good recovery (P = 0.018). When the nine brain regions were tested separately and results were corrected for multiple comparisons, no individual region differed significantly, but all estimated parameters indicated increased 123 I-CLINDE binding to TSPO, ranging from 2% to 19% in all patients at 1-2 weeks, 13% to 27% in patients with PCS at 3-4 months and -9% to 17% in patients with good recovery at 3-4 months. CONCLUSIONS: Neuroinflammation was present in mTBI at 1-2 weeks post-injury and persisted at 3-4 months post-injury with a tendency to be most pronounced in patients with PCS.


Assuntos
Concussão Encefálica/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Inflamação/diagnóstico por imagem , Adulto , Idoso , Encéfalo/metabolismo , Concussão Encefálica/metabolismo , Compostos Bicíclicos Heterocíclicos com Pontes , Feminino , Humanos , Inflamação/metabolismo , Masculino , Pessoa de Meia-Idade , Imagem Molecular , Síndrome Pós-Concussão , Tomografia Computadorizada de Emissão de Fóton Único , Adulto Jovem
3.
Gene Ther ; 24(4): 245-252, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28276446

RESUMO

Injecting proteins into the central nervous system that stimulate neuronal growth can lead to beneficial effects in animal models of disease. In particular, glial cell line-derived neurotrophic factor (GDNF) has shown promise in animal and cell models of Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis (ALS). Here, systemic AAV9-GDNF was delivered via tail vein injections to young rats to determine whether this could be a safe and functional strategy to treat the SOD1G93A rat model of ALS and, therefore, translated to a therapy for ALS patients. We found that GDNF administration in this manner resulted in modest functional improvement, whereby grip strength was maintained for longer and the onset of forelimb paralysis was delayed compared to non-treated rats. This did not, however, translate into an extension in survival. In addition, ALS rats receiving GDNF exhibited slower weight gain, reduced activity levels and decreased working memory. Collectively, these results confirm that caution should be applied when applying growth factors such as GDNF systemically to multiple tissues.


Assuntos
Esclerose Lateral Amiotrófica/terapia , Sistema Nervoso Central/fisiopatologia , Fator Neurotrófico Derivado de Linhagem de Célula Glial/uso terapêutico , Neurônios Motores/patologia , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/fisiopatologia , Animais , Sistema Nervoso Central/efeitos dos fármacos , Dependovirus/genética , Modelos Animais de Doenças , Terapia Genética , Vetores Genéticos/genética , Vetores Genéticos/uso terapêutico , Fator Neurotrófico Derivado de Linhagem de Célula Glial/efeitos adversos , Fator Neurotrófico Derivado de Linhagem de Célula Glial/genética , Força da Mão/fisiologia , Humanos , Neurônios Motores/metabolismo , Ratos , Medula Espinal/efeitos dos fármacos , Medula Espinal/fisiopatologia , Superóxido Dismutase/genética
4.
Antimicrob Agents Chemother ; 58(9): 5096-101, 2014 09.
Artigo em Inglês | MEDLINE | ID: mdl-24936595

RESUMO

Azole-resistant Aspergillus fumigatus harboring the TR34/L98H or TR46/Y121F/T289A alterations is increasingly found in Europe and Asia. Here, we present the first clinical cases of TR46/Y121/T289A and three cases of TR34/L98H outside the cystic fibrosis (CF) population in Denmark and the results of environmental surveys. Four patients (2012 to 2014) with 11 A. fumigatus and 4 Rhizomucor pusillus isolates and 239 soil samples (spring 2010 and autumn 2013, respectively) with a total of 113 A. fumigatus isolates were examined. Aspergillus isolates were screened for azole resistance using azole-containing agar. Confirmatory susceptibility testing was done using the EUCAST microbroth dilution EDEF 9.1 reference method. For relevant A. fumigatus isolates, CYP51A sequencing and microsatellite genotyping were performed. Three patients harbored TR34/L98H isolates. Two were azole naive at the time of acquisition and two were coinfected with wild-type A. fumigatus or R. pusillus isolates, complicating and delaying diagnosis. The TR46/Y121F/T289A strain was isolated in 2014 from a lung transplant patient. Genotyping indicated that susceptible and resistant Aspergillus isolates were unrelated and that no transmission between patients occurred. Azole resistance was not detected in any of the 113 soil isolates. TR34/L98H and TR46/Y121F/T289A alterations appear to be emerging in the clinical setting in Denmark and now involve azole-naive patients. Two recent soil-sampling surveys in Denmark were unable to indicate any increased prevalence of azole-resistant A. fumigatus in the environment. These findings further support the demand for real-time susceptibility testing of all clinically relevant isolates and for studies investigating the seasonal variation and ecological niches for azole-resistant environmental A. fumigatus.


Assuntos
Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/genética , Azóis/farmacologia , Adulto , Idoso , Antifúngicos/farmacologia , Aspergilose/tratamento farmacológico , Dinamarca , Farmacorresistência Fúngica/genética , Meio Ambiente , Feminino , Proteínas Fúngicas/genética , Genótipo , Humanos , Masculino , Testes de Sensibilidade Microbiana/métodos , Repetições de Microssatélites/genética , Pessoa de Meia-Idade
5.
Obesity (Silver Spring) ; 21(9): 1803-6, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23696269

RESUMO

OBJECTIVE: Dopamine plays an important role in both the rewarding and conditioning effects of food. These effects involve mesolimbic, mesocortical, and nigrostriatal pathways. In humans, the most consistent finding has been reduced striatal dopamine D2/3 receptor availability. In striatum, dopamine is inactivated by reuptake via the dopamine transporter (DAT). The aim of the study was to test the hypothesis of lower DAT availability in obese healthy subjects using a selective DAT radiotracer in a sample of subjects with a wide range of BMI values. DESIGN AND METHODS: Thirty-three healthy subjects with a mean age of 48.4 ± 13.3 (range, 21-71) years and a mean BMI of 29.6 ± 7.8 kg/m2 (range, 21.0-49.5) were included in the study. We used [123I]PE2I and SPECT to measure DAT availability. RESULTS: Using multiple linear regression analyses with striatal DAT as the dependent variable and BMI, age and gender as predictors was performed. We found no correlation between BMI and striatal DAT availability in striatum (P = 0.99), caudate nucleus (P = 0.61), and putamen (P = 0.30). Furthermore, we found no group difference between obese/severely obese (BMI > 30 kg/m2) and normal weight controls (BMI ≤ 25 kg/m2). CONCLUSIONS: We did not find any correlation between BMI and DAT availability in healthy volunteers.


Assuntos
Índice de Massa Corporal , Encéfalo/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Dopamina/metabolismo , Obesidade/metabolismo , Adulto , Idoso , Corpo Estriado/metabolismo , Feminino , Voluntários Saudáveis , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Valores de Referência
6.
Allergy ; 63(7): 865-71, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18588552

RESUMO

BACKGROUND: There is evidence that selenium levels are relatively low in Europe and may be falling. Low levels of selenium or low activity of some of the enzymes dependent on selenium have been associated with asthma. METHODS: The GA(2)LEN network has organized a multicentre case-control study in Europe to assess the relation of plasma selenium to asthma. The network compared 569 cases in 14 European centres with a diagnosis of asthma and reporting asthma symptoms in the last 12 months with 576 controls from the same centres with no diagnosis of asthma and no asthmatic symptoms in the last 12 months. RESULTS: All cases and controls were selected from the same population defined by age and place of residence. Mean plasma selenium concentrations among the controls ranged from 116.3 microg/l in Palermo to 67.7 microg/l in Vienna and 56.1 microg/l among the children in Oslo. Random effects meta-analysis of the results from the centres showed no overall association between asthma and plasma selenium [odds ratio (OR)/10 microg/l increase in plasma selenium: 1.04; 95% confidence interval (CI): 0.89-1.21] though there was a significantly protective effect in Lodz (OR: 0.48; 95% CI: 0.29-0.78) and a marginally significant adverse effect in Amsterdam (OR: 1.68; 95% CI: 0.98-2.90) and Ghent (OR: 1.35; 95% CI: 1.03-1.77). CONCLUSION: This study does not support a role for selenium in protection against asthma, but effect modification and confounding cannot be ruled out.


Assuntos
Asma/sangue , Asma/epidemiologia , Selênio/sangue , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Intervalos de Confiança , Fatores de Confusão Epidemiológicos , Suplementos Nutricionais , Europa (Continente)/epidemiologia , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Necessidades Nutricionais , Razão de Chances , Prevalência , Risco , Índice de Gravidade de Doença , Fumar
7.
Eur Respir J ; 32(5): 1231-6, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18579547

RESUMO

Studies from the UK and USA suggest that frequent use of paracetamol (acetaminophen) may increase the risk of asthma, but data across Europe are lacking. As part of a multicentric case-control study organised by the Global Allergy and Asthma European Network (GA(2)LEN), it was examined whether or not frequent paracetamol use is associated with adult asthma across Europe. The network compared 521 cases with a diagnosis of asthma and reporting of asthma symptoms within the last 12 months with 507 controls with no diagnosis of asthma and no asthmatic symptoms within the last 12 months across 12 European centres. All cases and controls were selected from the same population, defined by age (20-45 yrs) and place of residence. In a random effects meta-analysis, weekly use of paracetamol, compared with less frequent use, was strongly positively associated with asthma after controlling for confounders. There was no evidence for heterogeneity across centres. No association was seen between use of other analgesics and asthma. These data add to the increasing and consistent epidemiological evidence implicating frequent paracetamol use in asthma in diverse populations.


Assuntos
Acetaminofen/efeitos adversos , Asma/complicações , Dor/complicações , Dor/tratamento farmacológico , Adulto , Analgésicos/efeitos adversos , Asma/tratamento farmacológico , Asma/etiologia , Estudos de Casos e Controles , Europa (Continente)/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Risco , Resultado do Tratamento
8.
Atherosclerosis ; 196(2): 937-42, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17418218

RESUMO

PURPOSE: The purpose was to investigate in a large, randomized, double-blinded, placebo-controlled trial, whether antibiotic treatment can prevent progression of peripheral arterial disease (PAD). MATERIAL AND METHODS: Five hundred and seven patients were included; all patients had an established diagnosis of PAD. Their mean age was 66 years (36-85), and 59% were males. Patients were randomized to Roxithromycin 300 mg daily for 28 days. Baseline investigations were ankle blood pressure, ankle-brachial blood pressure index (ABPI), walking distance, C. pneumoniae serology, cholesterol and medical history. Follow-up was performed every 6 months. Primary events were defined as death, peripheral revascularization and major lower limb amputation. Secondary events were thrombosis, stroke, transient cerebral ischaemic attack and myocardial infarction. Change in ABPI was also investigated. Data were analyzed mainly by Cox regression and linear regression. RESULTS: Included patients with PAD were randomized. Two patients withdrew. Of the remaining, 248 received roxithromycin and 257 placebo. In the treatment group 55% were seropositive and 53% in the placebo group. Mean follow-up was 2.1 years (range 0.06-5.1 years). In the placebo group, 26 died and 80 primary events occurred in total. In the treatment group, 28 died and 74 primary events were observed. The hazard ratio of death was 1.13 (95% CI: 0.68; 1.90), and of primary events 0.92 (95% CI: 0.67; 1.26). Also on secondary events and ABPI changes, no significant differences were found. CONCLUSION: Long-term treatment with roxithromycin is ineffective in preventing death, amputation, peripheral revascularization, myocardial infarction, stroke, transient cerebral ischaemic attack, thrombosis and decline in ABPI in patients with an established diagnosis of PAD.


Assuntos
Infecções por Chlamydophila/tratamento farmacológico , Chlamydophila pneumoniae , Doenças Vasculares Periféricas/tratamento farmacológico , Roxitromicina/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Vasculares Periféricas/mortalidade , Resultado do Tratamento
9.
Eur J Nucl Med Mol Imaging ; 31(12): 1631-8, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15583914

RESUMO

PURPOSE: The aim of this study was to ascertain whether combined presynaptic and postsynaptic dopaminergic single-photon emission computed tomography (SPECT) scanning is useful for differentiation between patients with idiopathic Parkinson's disease (IPD), patients with multiple system atrophy of the striatonigral type (MSA) and healthy subjects. METHODS: SPECT measurements of the dopamine transporter (DAT) were done with 123I-beta-CIT, while for determination of the dopamine D2-like receptors (D2), 123I-epidepride was used. Clinical evaluation and SPECT scans were carried out in 14 patients with IPD, eight patients with MSA and 11 healthy age-matched control subjects. RESULTS: Putaminal DAT binding was reduced to 32% of control values in IPD and to 19% of control values in MSA . Significantly higher striatal asymmetry in DAT binding was found in MSA than in controls, but IPD patients had significantly higher asymmetry than MSA patients. Striatal D2 binding did not differ significantly between patients and healthy controls but the ratio between caudate DAT and D2 binding was significantly higher in patients with IPD than in those with MSA, even when disease severity was taken into account. CONCLUSION: Patients with reduced striatal 123I-beta-CIT binding and a side-to-side difference greater than 15% are likely to suffer from IPD. Patients with reduced striatal 123I-beta-CIT binding and a side-to-side difference of between 5% and 15% are more likely to have MSA. 123I-epidepride SPECT measurements may add further diagnostic information, since the ratio between DAT and D2 receptor binding is significantly higher in IPD than in MSA.


Assuntos
Cocaína/análogos & derivados , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Atrofia de Múltiplos Sistemas/diagnóstico por imagem , Atrofia de Múltiplos Sistemas/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/metabolismo , Receptores de Dopamina D2/metabolismo , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Adulto , Idoso , Benzamidas/farmacocinética , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Cocaína/farmacocinética , Diagnóstico Diferencial , Proteínas da Membrana Plasmática de Transporte de Dopamina , Feminino , Humanos , Radioisótopos do Iodo/farmacocinética , Masculino , Pessoa de Meia-Idade , Pirrolidinas/farmacocinética , Compostos Radiofarmacêuticos/farmacocinética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
10.
Occup Environ Med ; 60(9): E8, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12937204

RESUMO

BACKGROUND: The physical and psychosocial work environment is expected to modify recovery from shoulder disorders, but knowledge is limited. METHODS: In a follow up study of musculoskeletal disorders in industrial and service workers, 113 employees were identified with a history of shoulder pain combined with clinical signs of shoulder tendonitis. The workers had yearly re-examinations up to three times. Quantitative estimates of duration, repetitiveness, and forcefulness of current tasks were obtained from video recordings. Perception of job demands, decision latitude, and social support was recorded by a job content questionnaire. Recovery of shoulder tendonitis was analysed by Kaplan-Meier survival technique and by logistic regression on exposure variables and individual characteristics in models, allowing for time varying exposures. RESULTS: Some 50% of workers recovered within 10 months (95% CI 6 to 14 months). Higher age was strongly related to slow recovery, while physical job exposures were not. Perception of demands, control, and social support at the time when the shoulder disorder was diagnosed, were associated with delayed recovery, but these psychosocial factors did not predict slow recovery in incident cases identified during follow up. CONCLUSION: The median duration of shoulder tendonitis in a cross sectional sample of industrial and service workers was in the order of 10 months. This estimate is most likely biased towards too high a value. Recovery was strongly reduced in higher age. Physical workplace exposures and perceived psychosocial job characteristics during the period preceding diagnosis seem not to be important prognostic factors.


Assuntos
Transtornos Traumáticos Cumulativos/etiologia , Doenças Profissionais/etiologia , Lesões do Ombro , Tendinopatia/etiologia , Idoso , Estudos de Coortes , Dinamarca , Feminino , Seguimentos , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Prognóstico , Recuperação de Função Fisiológica , Análise de Regressão , Inquéritos e Questionários
11.
Acta Anaesthesiol Scand ; 46(5): 567-78, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12027852

RESUMO

BACKGROUND: The optimal arterial carbon dioxide tension (P(a)CO(2)) in patients with acute bacterial meningitis (ABM) is unknown and controversial. The objective of this study was to measure global cerebral blood flow (CBF), cerebrovascular CO(2) reactivity (CO(2)R), and cerebral metabolic rates (CMR) of oxygen (O(2)), glucose (glu), and lactate (lac), in patients with ABM and compare the results to those obtained in healthy volunteers. METHODS: We studied 19 patients (17 of whom were sedated) with ABM and eight healthy volunteers (controls). CBF was measured during baseline ventilation and hyperventilation with single-photon emission computed tomography (SPECT) (14 patients) and/or the Kety-Schmidt technique (KS) (11 patients and all controls). In KS studies, CMR was measured by multiplying the arterial to jugular venous concentration difference (a-v D) by CBF. RESULTS: CBF did not differ significantly among groups, although a larger variation was seen in patients than in controls. CO(2)R was not significantly different among groups. At baseline, patients had significantly lower a-v DO(2), CMR(O(2)), CMR(glu), and CMR(lac) than controls. CMR(O(2)) did not change between hyperventilation compared to baseline ventilation, whereas CMR(glu) increased. CONCLUSION: In patients with acute bacterial meningitis, we found variable levels of CBF and cerebrovascular CO(2) reactivity, a low a-v DO(2), low cerebral metabolic rates of oxygen and glucose, and a cerebral lactate efflux. In these patients, a ventilation strategy guided by jugular bulb oximetry and/or repeated CBF measurements may be more optimal in terms of cerebral oxygenation than a strategy aiming at identical levels of P(a)CO(2) for all patients.


Assuntos
Dióxido de Carbono/sangue , Circulação Cerebrovascular/fisiologia , Meningites Bacterianas/sangue , Meningites Bacterianas/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Glicemia/metabolismo , Química Encefálica/fisiologia , Feminino , Humanos , Ácido Láctico/sangue , Masculino , Pessoa de Meia-Idade , Oxirredução , Oxigênio/sangue , Consumo de Oxigênio/fisiologia , Estudos Prospectivos , Tomografia Computadorizada de Emissão de Fóton Único
12.
Stroke ; 32(11): 2530-3, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11692012

RESUMO

BACKGROUND AND PURPOSE: Arterial blood pressure and cardiac output are often reduced in patients with chronic heart failure (CHF). Counterregulatory mechanisms with increased neurohormonal activation and changes in the distribution of cardiac output are assumed to secure vital organ perfusion. However, clinical examination of patients with CHF frequently reveals neurological symptoms with dizziness and memory problems, suggesting altered brain perfusion. In this study we determined whether cerebral blood flow (CBF) is reduced in patients with New York Heart Association (NYHA) functional class III and IV (n=12) compared with healthy control subjects (n=12). Furthermore, we examined whether heart transplantation (n=5) could restore CBF. METHODS: CBF was estimated by single-photon emission computed tomography and (133)Xe as tracer, and middle cerebral artery velocity was measured by transcranial Doppler ultrasound. RESULTS: In the CHF patients, CBF was 36+/-1 mL/min per 100 g, corresponding to a 31% reduction compared with the control group (52+/-5 mL/min per 100 g) (P<0.05). After heart transplantation, CBF increased from 35+/-3 mL/min per 100 g before transplantation to 50+/-3 mL/min per 100 g within the first postoperative month (P<0.05). CONCLUSIONS: We conclude that CBF is substantially, but reversibly, reduced in patients with NYHA class III/IV heart failure. This phenomenon suggests that redistribution of cardiac output inadequately secures brain perfusion in patients with severe CHF.


Assuntos
Circulação Cerebrovascular , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/cirurgia , Transplante de Coração , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea , Dióxido de Carbono/análise , Doença Crônica , Feminino , Insuficiência Cardíaca/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/diagnóstico por imagem , Tomografia Computadorizada de Emissão , Ultrassonografia Doppler Transcraniana
13.
Respiration ; 68(4): 416-9, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11464092

RESUMO

A 74-year-old woman presented with a 2-day history of cough, dyspnea and wheezing following aspiration of a tetracycline tablet. She developed a left lower lobe pneumonitis, and bronchoscopy revealed left main bronchus narrowing and exudate. The course of this patient is discussed in reference to the available literature on toxic aspirations.


Assuntos
Brônquios , Corpos Estranhos/complicações , Inalação , Pneumonia/etiologia , Idoso , Broncoscopia , Feminino , Humanos , Tetraciclina
14.
Mol Cell ; 6(6): 1365-75, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11163210

RESUMO

Ubiquitin-mediated proteolysis regulates the activity of diverse receptor systems. Here, we identify Smurf2, a C2-WW-HECT domain ubiquitin ligase and show that Smurf2 associates constitutively with Smad7. Smurf2 is nuclear, but binding to Smad7 induces export and recruitment to the activated TGF beta receptor, where it causes degradation of receptors and Smad7 via proteasomal and lysosomal pathways. IFN gamma, which stimulates expression of Smad7, induces Smad7-Smurf2 complex formation and increases TGF beta receptor turnover, which is stabilized by blocking Smad7 or Smurf2 expression. Furthermore, Smad7 mutants that interfere with recruitment of Smurf2 to the receptors are compromised in their inhibitory activity. These studies thus define Smad7 as an adaptor in an E3 ubiquitin-ligase complex that targets the TGF beta receptor for degradation.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Ligases/metabolismo , Proteínas Nucleares/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Transativadores/metabolismo , Animais , Linhagem Celular , Cisteína Endopeptidases/metabolismo , Proteínas de Ligação a DNA/genética , Regulação para Baixo/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Immunoblotting , Interferon gama/farmacologia , Ligases/química , Lisossomos/metabolismo , Substâncias Macromoleculares , Modelos Biológicos , Dados de Sequência Molecular , Complexos Multienzimáticos/metabolismo , Mutação , Complexo de Endopeptidases do Proteassoma , Ligação Proteica/efeitos dos fármacos , Estrutura Terciária de Proteína , Transporte Proteico , Proteínas Recombinantes de Fusão , Proteína Smad7 , Transativadores/genética , Transfecção , Ubiquitina-Proteína Ligases
15.
Ugeskr Laeger ; 161(18): 2680-1, 1999 May 03.
Artigo em Dinamarquês | MEDLINE | ID: mdl-10434791

RESUMO

Spontaneous rupture of the kidney with perirenal haemorrhage is a rare and serious complication of polyarteritis nodosa (PAN), usually requiring urgent surgery. The present case was a 28-year old male, who had been ill for 14 days, with abdominal pain, loss of appetite, nausea and vomiting. The patient was in shock on hospital admission. Explorative laparotomy revealed a massive haemorrhage from the right kidney. The kidney was removed and histological examination of the specimen revealed polyarteritis nodosa. The clinical history of the presented case is similar to previously described cases of kidney rupture in PAN. In the case presented, however, the diagnosis was first established histologically, while the diagnosis in most of the former cases was established on renal angiography, with findings of spindle-formed renal aneurysms.


Assuntos
Hemorragia/etiologia , Nefropatias/etiologia , Rim/lesões , Poliarterite Nodosa/complicações , Adulto , Diagnóstico Diferencial , Hemorragia/diagnóstico , Hemorragia/cirurgia , Humanos , Rim/patologia , Nefropatias/diagnóstico , Nefropatias/cirurgia , Masculino , Nefrectomia , Poliarterite Nodosa/diagnóstico , Poliarterite Nodosa/patologia , Artéria Renal/patologia , Ruptura Espontânea
17.
Nature ; 400(6745): 687-93, 1999 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-10458166

RESUMO

The TGF-beta superfamily of proteins regulates many different biological processes, including cell growth, differentiation and embryonic pattern formation. TGF-beta-like factors signal across cell membranes through complexes of transmembrane receptors known as type I and type II serine/threonine-kinase receptors, which in turn activate the SMAD signalling pathway. On the inside of the cell membrane, a receptor-regulated class of SMADs are phosphorylated by the type-I-receptor kinase. In this way, receptors for different factors are able to pass on specific signals along the pathway: for example, receptors for bone morphogenetic protein (BMP) target SMADs 1, 5 and 8, whereas receptors for activin and TGF-beta target SMADs 2 and 3. Phosphorylation of receptor-regulated SMADs induces their association with Smad4, the 'common-partner' SMAD, and stimulates accumulation of this complex in the nucleus, where it regulates transcriptional responses. Here we describe Smurf1, a new member of the Hect family of E3 ubiquitin ligases. Smurf1 selectively interacts with receptor-regulated SMADs specific for the BMP pathway in order to trigger their ubiquitination and degradation, and hence their inactivation. In the amphibian Xenopus laevis, Smurf1 messenger RNA is localized to the animal pole of the egg; in Xenopus embryos, ectopic Smurf1 inhibits the transmission of BMP signals and thereby affects pattern formation. Smurf1 also enhances cellular responsiveness to the Smad2 (activin/TGF-beta) pathway. Thus, targeted ubiquitination of SMADs may serve to control both embryonic development and a wide variety of cellular responses to TGF-beta signals.


Assuntos
Padronização Corporal/fisiologia , Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas de Ligação a DNA/metabolismo , Ligases/metabolismo , Transdução de Sinais , Transativadores/metabolismo , Animais , Células COS , Linhagem Celular , Clonagem Molecular , Ectoderma/metabolismo , Embrião não Mamífero/metabolismo , Humanos , Ligases/genética , Dados de Sequência Molecular , Fosfoproteínas/metabolismo , Proteínas Smad , Proteína Smad2 , Proteína Smad5 , Fator de Crescimento Transformador beta/metabolismo , Ubiquitina-Proteína Ligases , Ubiquitinas/metabolismo , Xenopus , Proteínas de Xenopus
18.
Dis Colon Rectum ; 42(1): 56-65, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10211521

RESUMO

PURPOSE: The aim of the present study was to study whether patients developing anastomotic leakage after colorectal resections for colorectal cancer have laboratory signs of an altered hemostatic balance in the systemic circulation, preoperatively and postoperatively, causing an impaired healing process. METHODS: Patients operated on for colorectal cancer were studied. Seventeen consecutive patients with anastomotic leakage and 17 patients without anastomotic leakage were matched according to age, gender, tumor stage, and localization of tumor. Hemostatic balance was estimated preoperatively and at one, two, and seven days and at three months after surgery by plasma levels of sensitive markers of coagulation activation and fibrinolysis, i.e., prothrombin fragment 1 + 2, thrombin-antithrombin complexes, soluble fibrin, tissue-type plasminogen activator activity, and plasminogen activator inhibitor Type 1. RESULTS: Preoperatively, the hemostatic balance was comparable in patients with and without anastomotic leakage. In the early postoperative period, patients developing anastomotic leakage exhibited signs of systemic coagulation activation, i.e., elevated plasma levels of prothrombin fragment 1 + 2, thrombin-antithrombin complexes, soluble fibrin, and plasminogen activator inhibitor Type 1. The observed coagulation activation appeared before the anastomotic leakage became clinically evident. More patients with anastomotic leakage received perioperative blood transfusions than patients without leakage, despite the fact that duration of surgery and intraoperative blood loss were comparable in the two groups. CONCLUSIONS: Enhanced coagulation activity was observed postoperatively in patients developing anastomotic leakage after colorectal resections for colorectal cancer. Such a hypercoagulable state may contribute to the development of anastomotic leakage by facilitating formation of microthromboses in the perianastomotic area.


Assuntos
Coagulação Sanguínea , Neoplasias Colorretais/cirurgia , Fibrinólise , Deiscência da Ferida Operatória/etiologia , Fatores Etários , Anastomose Cirúrgica , Neoplasias Colorretais/sangue , Feminino , Fibrina/análise , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Inibidor 1 de Ativador de Plasminogênio/análise , Complicações Pós-Operatórias , Protrombina/análise , Fatores Sexuais , Deiscência da Ferida Operatória/sangue , Trombina/análise
19.
Dev Biol ; 207(2): 364-79, 1999 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-10068469

RESUMO

Smads are central mediators of signal transduction for the TGFbeta superfamily. However, the precise functions of Smad-mediated signaling pathways in early development are unclear. Here we demonstrate a requirement for Smad2 signaling in dorsoanterior axis formation during Xenopus development. Using two point mutations of Smad2 previously identified in colorectal carcinomas, we show that Smad2 ushers Smad4 to the nucleus to form a transcriptional activation complex with the nuclear DNA-binding protein FAST-1 and that the mutant proteins interact normally with FAST-1 but fail to recruit Smad4 into the nucleus. This mechanism of inhibition specifically restricts the dominant-negative activity of these mutants to the activin/Vg1 signaling pathway without inhibiting BMPs. Furthermore, expression of these mutants in Xenopus animal caps inhibits but does not abolish activin and Vg1 induction of mesoderm and in the embryo results in a truncated dorsoanterior axis. These studies define a mechanism through which mutations in Smad2 may block TGFbeta-dependent signaling and suggest a critical role for inductive signaling mediated by the Smad2 pathway in Xenopus organizer function.


Assuntos
Proteínas de Ligação a DNA/genética , Inibinas/genética , Transdução de Sinais/genética , Transativadores/genética , Proteínas de Xenopus , Xenopus/embriologia , Receptores de Ativinas Tipo I , Ativinas , Animais , Células COS , Desenvolvimento Embrionário , Fatores de Transcrição Forkhead , Regulação da Expressão Gênica no Desenvolvimento/genética , Morfogênese , Mutação , Fatores de Crescimento Neural , Fosforilação , RNA Mensageiro/metabolismo , Receptores de Fatores de Crescimento/genética , Proteínas Smad , Proteína Smad2 , Proteína Smad4 , Fatores de Transcrição/genética , Ativação Transcricional/genética , Transfecção , Fator de Crescimento Transformador beta/genética
20.
Development ; 126(8): 1739-51, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10079235

RESUMO

Mutations in the Tbx5 transcription factor cause heart septal defects found in human Holt-Oram Syndrome. The complete extent to which Tbx5 functions in heart development, however, has not been established. Here we show that, in Xenopus embryos, Tbx5 is expressed in the early heart field, posterior to the cardiac homeobox transcription factor, Nkx2.5. During morphogenesis, Tbx5 is expressed throughout the heart tube except the anterior portion, the bulbus cordis. When Tbx5 activity is antagonized with a hormone-inducible, dominant negative version of the protein, the heart fails to develop. These results suggest that, in addition to its function in heart septation, Tbx5 has a more global role in cardiac specification and heart development in vertebrate embryos.


Assuntos
Coração/embriologia , Proteínas com Domínio T , Fatores de Transcrição/fisiologia , Proteínas de Xenopus , Sequência de Aminoácidos , Animais , Sequência de Bases , DNA Complementar , Olho/embriologia , Olho/metabolismo , Expressão Gênica , Homologia de Genes , Proteína Homeobox Nkx-2.5 , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Hormônios/farmacologia , Humanos , Mesoderma , Camundongos , Dados de Sequência Molecular , Morfogênese , Fenótipo , Receptores de Glucocorticoides/metabolismo , Fatores de Transcrição/genética , Xenopus laevis/embriologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...