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1.
Rheumatology (Oxford) ; 56(11): 1993-2003, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-28968735

RESUMO

Objectives: To assess long-term efficacy, safety and tolerability of secukinumab up to 104 weeks in patients with active PsA. Methods: Patients with PsA (n = 397) were randomized to s.c. secukinumab 300, 150 or 75 mg or placebo at baseline, weeks 1, 2, 3 and 4 and every 4 weeks thereafter. Placebo-treated patients were re-randomized to receive secukinumab 300 or 150 mg s.c. from week 16 (placebo non-responders) or week 24 (placebo responders). Exploratory endpoints at week 104 included 20, 50 and 70% improvement in ACR criteria (ACR20, 50, 70); 75 and 90% improvement in the Psoriasis Area Severity Index, 28-joint DAS with CRP, presence of dactylitis and enthesitis and other patient-reported outcomes. For binary variables, missing values were imputed; continuous variables were analysed by a mixed-effects model for repeated measures. Results: A total of 86/100 (86%), 76/100 (76%) and 65/99 (66%) patients in the secukinumab 300, 150 and 75 mg groups, respectively, completed 104 weeks. At week 104, ACR20 response rates after multiple imputation in the 300, 150 and 75 mg groups were 69.4, 64.4 and 50.3%, respectively. Sustained clinical improvements were observed through week 104 with secukinumab across other clinically important domains of PsA. Responses were sustained through week 104 regardless of prior anti-TNF-α use. Over the entire treatment period the incidence, type and severity of adverse events were consistent with those reported previously. Conclusion: Secukinumab provided sustained improvements in signs and symptoms and multiple clinical domains in patients of active PsA through 2 years of therapy. Secukinumab was well tolerated, with a safety profile consistent with that reported previously. Trial registration: ClinicalTrials.gov (https://clinicaltrials.gov), NCT01752634.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Antirreumáticos/uso terapêutico , Artrite Psoriásica/tratamento farmacológico , Anticorpos Monoclonais Humanizados , Artrite Psoriásica/metabolismo , Artrite Psoriásica/fisiopatologia , Proteína C-Reativa/metabolismo , Diarreia/induzido quimicamente , Método Duplo-Cego , Quimioterapia Combinada , Glucocorticoides/uso terapêutico , Humanos , Modelos Logísticos , Estudos Longitudinais , Metotrexato/uso terapêutico , Nasofaringite/induzido quimicamente , Medidas de Resultados Relatados pelo Paciente , Qualidade de Vida , Infecções Respiratórias/induzido quimicamente , Índice de Gravidade de Doença , Resultado do Tratamento
2.
J Allergy Clin Immunol ; 137(5): 1413-1422.e12, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27006248

RESUMO

BACKGROUND: There is a paucity of studies comparing asthma and chronic obstructive pulmonary disease (COPD) based on thoracic quantitative computed tomographic (QCT) parameters. OBJECTIVES: We sought to compare QCT parameters of airway remodeling, air trapping, and emphysema between asthmatic patients and patients with COPD and explore their relationship with airflow limitation. METHODS: Asthmatic patients (n = 171), patients with COPD (n = 81), and healthy subjects (n = 49) recruited from a single center underwent QCT and clinical characterization. RESULTS: Proximal airway percentage wall area (%WA) was significantly increased in asthmatic patients (62.5% [SD, 2.2]) and patients with COPD (62.7% [SD, 2.3]) compared with that in healthy control subjects (60.3% [SD, 2.2], P < .001). Air trapping measured based on mean lung density expiratory/inspiratory ratio was significantly increased in patients with COPD (mean, 0.922 [SD, 0.037]) and asthmatic patients (mean, 0.852 [SD, 0.061]) compared with that in healthy subjects (mean, 0.816 [SD, 0.066], P < .001). Emphysema assessed based on lung density measured by using Hounsfield units below which 15% of the voxels lie (Perc15) was a feature of COPD only (patients with COPD: mean, -964 [SD, 19.62] vs asthmatic patients: mean, -937 [SD, 22.7] and healthy subjects: mean, -937 [SD, 17.1], P < .001). Multiple regression analyses showed that the strongest predictor of lung function impairment in asthmatic patients was %WA, whereas in the COPD and asthma subgrouped with postbronchodilator FEV1 percent predicted value of less than 80%, it was air trapping. Factor analysis of QCT parameters in asthmatic patients and patients with COPD combined determined 3 components, with %WA, air trapping, and Perc15 values being the highest loading factors. Cluster analysis identified 3 clusters with mild, moderate, or severe lung function impairment with corresponding decreased lung density (Perc15 values) and increased air trapping. CONCLUSIONS: In asthmatic patients and patients with COPD, lung function impairment is strongly associated with air trapping, with a contribution from proximal airway narrowing in asthmatic patients.


Assuntos
Remodelação das Vias Aéreas , Asma , Doença Pulmonar Obstrutiva Crônica , Enfisema Pulmonar , Adulto , Idoso , Asma/diagnóstico por imagem , Asma/patologia , Asma/fisiopatologia , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/diagnóstico por imagem , Doença Pulmonar Obstrutiva Crônica/patologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Enfisema Pulmonar/diagnóstico por imagem , Enfisema Pulmonar/patologia , Enfisema Pulmonar/fisiopatologia , Tomografia Computadorizada por Raios X
3.
Gut ; 64(2): 233-42, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24700437

RESUMO

BACKGROUND: Anti-tumour necrosis factor α (TNFα) therapy effectively induces and maintains remission in Crohn's disease (CD). Up to 40% of patients, however, fail to respond to anti-TNFα. OBJECTIVE: To identify the mechanisms underlying the persistence of mucosal lesions in patients who fail to respond to anti-TNFα therapy. DESIGN: An observational study based on whole-genome transcriptional analysis was carried out using intestinal biopsy specimens from patients with CD receiving (n=12) or not (n=10) anti-TNFα therapy. The transcriptional signature of responders was compared with that of non-responders after anti-TNFα therapy. Controls with non-inflammatory bowel disease (non-IBD) (n=17) were used for comparisons. Genes of interest were validated by real-time RT-PCR in an independent cohort of patients with CD receiving (n=17) or not (n=16) anti-TNFα and non-IBD controls (n=7). RESULTS: We confirmed that response to anti-TNFα is accompanied by significant regulation of a large number of genes, including IL1B, S100A8, CXCL1, which correlated with endoscopic activity. Remarkably, patients who failed to respond to anti-TNFα showed a mixed signature, maintaining increased expression of IL1B, IL17A and S100A8, while showing significant modulation of other genes commonly upregulated in active CD, including IL6 and IL23p19. CONCLUSIONS: Our results show that anti-TNFα therapy significantly downregulates a subset of inflammatory genes even in patients who fail to achieve endoscopic remission, suggesting that these genes may not be dominant in driving inflammation in non-responders. On the other hand, we identified IL1B and IL17A as genes that remained altered in non-responders, pointing to potentially more relevant targets for modulating mucosal damage in refractory patients.


Assuntos
Doença de Crohn/tratamento farmacológico , Fármacos Gastrointestinais/uso terapêutico , Mediadores da Inflamação/metabolismo , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adalimumab , Adulto , Idoso , Anti-Inflamatórios não Esteroides/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Colo/metabolismo , Doença de Crohn/genética , Doença de Crohn/metabolismo , Feminino , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Infliximab , Interleucina-6/biossíntese , Interleucina-6/genética , Mucosa Intestinal/metabolismo , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Ativação Transcricional , Falha de Tratamento , Adulto Jovem
4.
Respir Res ; 14: 17, 2013 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-23398985

RESUMO

BACKGROUND: Severe asthma is a heterogeneous disease and the relationship between airway inflammation and airway remodelling is poorly understood. We sought to define sputum mediator profiles in severe asthmatics categorised by CT-determined airway geometry and sputum differential cell counts. METHODS: In a single centre cross-sectional observational study we recruited 59 subjects with severe asthma that underwent sputum induction and thoracic CT. Quantitative CT analysis of the apical segment of the right upper lobe (RB1) was performed. Forty-one mediators in sputum samples were measured of which 21 mediators that were assessable in >50% of samples were included in the analyses. RESULTS: Independent of airway geometry, sputum MMP9 and IL-1ß were elevated in those groups with a high sputum neutrophil count while sputum ICAM was elevated in those subjects with a low sputum neutrophil count. In contrast, sputum CCL11, IL-1α and fibrinogen were different in groups stratified by both sputum neutrophil count and airway geometry. Sputum CCL11 concentration was elevated in subjects with a low sputum neutrophil count and high luminal and total RB1 area, whereas sputum IL1α was increased in subjects with a high sputum neutrophil count and low total RB1 area. Sputum fibrinogen was elevated in those subjects with RB1 luminal narrowing and in those subjects with neutrophilic inflammation without luminal narrowing. CONCLUSIONS: We have demonstrated that sputum mediator profiling reveals a number of associations with airway geometry. Whether these findings reflect important biological phenotypes that might inform stratified medicine approaches requires further investigation.


Assuntos
Remodelação das Vias Aéreas , Asma/diagnóstico , Mediadores da Inflamação/análise , Pulmão/diagnóstico por imagem , Pulmão/imunologia , Escarro/imunologia , Tomografia Computadorizada por Raios X , Adulto , Asma/diagnóstico por imagem , Asma/imunologia , Biomarcadores/análise , Quimiocina CCL11/análise , Estudos Transversais , Inglaterra , Feminino , Fibrinogênio/análise , Humanos , Molécula 1 de Adesão Intercelular/análise , Interleucina-1alfa/análise , Interleucina-1beta/análise , Contagem de Leucócitos , Masculino , Metaloproteinase 9 da Matriz/análise , Pessoa de Meia-Idade , Neutrófilos/imunologia , Fenótipo , Valor Preditivo dos Testes , Estudos Retrospectivos , Índice de Gravidade de Doença
5.
Am J Physiol Lung Cell Mol Physiol ; 297(3): L530-7, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19542247

RESUMO

Respiratory infections exacerbate chronic lung diseases promoting airway inflammation and hyperreactivity. Toll-like receptor 3 (TLR3) recognizes viral double-stranded (ds) RNA such as polyinosinic-polycytidylic acid [poly(I:C)] and stimulates innate immune responses. The objective of this study was to test the hypothesis that dsRNA promotes lung inflammation and alters airway responsiveness to cholinergic and beta-adrenergic receptor agonists in human lung slices. Human airway smooth muscle (ASM) was incubated for 24 h in poly(I:C) +/- TNFalpha and a TLR3 monoclonal antibody. Precision-cut lung slices (PCLS; 250-microm thickness) from healthy human lungs containing a small airway were incubated in 0, 10, or 100 microg/ml poly(I:C) for 24 h. Intravital microscopy of lung slices was used to quantify contractile and relaxation responsiveness to carbachol and isoproterenol, respectively. Supernatants of ASM and PCLS were analyzed for cytokine secretion using a 25-multiplex bead assay. In human ASM, poly(I:C) (0.5 microg/ml) increased macrophage inflammatory protein-1alpha (MIP-1alpha) and RANTES that was prevented by a TLR3 monoclonal receptor antibody. Incubation of human PCLS with poly(I:C) (10 and 100 microg/ml) had little effect on the log EC(50) or maximum drug effect (E(max)) for contraction and relaxation in response to carbachol and isoproterenol, respectively. The responsiveness of the same human PCLS to poly(I:C) incubation was confirmed by the robust increase in chemokines and cytokines. In separate experiments, incubation of PCLS with IL-13 or TNFalpha (100 ng/ml) increased airway sensitivity to carbachol. Poly(I:C) promotes inflammatory mediator release that was not associated with enhanced bronchoconstriction or attenuated bronchodilation in normal healthy human lung slices. Transduction at the TLR3 initiated by dsRNA stimulates downstream innate immune responses.


Assuntos
Citocinas/metabolismo , Contração Muscular/efeitos dos fármacos , Relaxamento Muscular/efeitos dos fármacos , Poli I-C/farmacologia , Receptor 3 Toll-Like/metabolismo , Traqueia/efeitos dos fármacos , Traqueia/fisiologia , Quimiocinas/metabolismo , Humanos , Técnicas In Vitro , Interleucina-13/farmacologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Traqueia/citologia , Fator de Necrose Tumoral alfa/farmacologia
6.
Pharmacol Ther ; 114(2): 129-45, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17408750

RESUMO

The developing lung is highly susceptible to damage from exposure to environmental toxicants particularly due to the protracted maturation of the respiratory system, extending from the embryonic phase of development in utero through to adolescence. The functional organization of the lungs requires a coordinated ontogeny of critical developmental processes that include branching morphogenesis, cellular differentiation and proliferation, alveolarization, and maturation of the pulmonary immune, vasculature, and neural systems. Therefore, exposure to environmental pollutants during crucial periods of prenatal and/or postnatal development may determine the course of lung morphogenesis and maturation. Depending on the timing of exposure and pathobiological response of the affected tissue, exposure to environmental pollutants can potentially result in long-term alterations that affect the structure and function of the respiratory system. Besides an immature respiratory system at birth, children possess unique differences in their physiology and behavioral characteristics compared to adults that are believed to augment the vulnerability of their developing lungs to perturbations by environmental toxins. Furthermore, an interaction between genetic predisposition and increased opportunity for exposure to chemical and infectious disease increase the hazards and risks for infants and children. In this article, the evidence for perturbations of lung developmental processes by key ambient pollutants (environmental tobacco smoke [ETS], ozone, and particulate matter [PM]) are discussed in terms of biological factors that are intrinsic to infants and children and that influence exposure-related lung development and respiratory outcomes.


Assuntos
Poluição do Ar/efeitos adversos , Desenvolvimento Fetal/fisiologia , Pulmão/embriologia , Pulmão/crescimento & desenvolvimento , Adolescente , Fatores Etários , Criança , Pré-Escolar , Feminino , Desenvolvimento Fetal/efeitos dos fármacos , Humanos , Lactente , Recém-Nascido , Pulmão/efeitos dos fármacos , Pneumopatias/induzido quimicamente , Pneumopatias/etiologia , Pneumopatias/fisiopatologia , Estado Nutricional , Ozônio/toxicidade , Gravidez , Fenômenos Fisiológicos Respiratórios/efeitos dos fármacos , Fatores de Risco , Poluição por Fumaça de Tabaco/efeitos adversos
7.
Respir Physiol Neurobiol ; 160(1): 28-36, 2008 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-17884737

RESUMO

Calcitonin gene-related peptide (CGRP) is located with substance P in nerve varicosities in close apposition to principal neurons in airway parasympathetic ganglia. Substance P has multiple effects on airway parasympathetic neurons but the role of CGRP is unknown. Using intracellular current clamp recording of ganglionic neurons, stimulation of vagal afferent nerves in the presence of neurokinin receptor antagonists evoked hyperpolarization of the membrane potential which was blocked by the CGRP-1 receptor antagonist, CGRP(8-37). Exogenous application of alpha-CGRP (0.001-0.1 microM) hyperpolarized the membrane potential, which was either blocked or reversed to depolarization in the presence of CGRP(8-37), whereas higher concentrations of alpha-CGRP (1.0-10.0 microM) caused depolarization. Action potential accommodation in phasic-type neurons decreased in the presence of alpha-CGRP (0.1-10 microM). The co-localization of substance P- and CGRP-immunoreactivity was observed in nerve varicosities within ganglia; prolonged exposure to capsaicin in vitro depleted substance P and CGRP immunostaining in nerve varicosities. These results demonstrate that CGRP has multiple effects on the excitability of airway parasympathetic neurons and may alter their activity, ultimately affecting parasympathetic tone in the lower airways.


Assuntos
Brônquios/inervação , Peptídeo Relacionado com Gene de Calcitonina/fisiologia , Sistema Nervoso Parassimpático/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Animais , Brônquios/efeitos dos fármacos , Peptídeo Relacionado com Gene de Calcitonina/antagonistas & inibidores , Capsaicina/farmacologia , Interpretação Estatística de Dados , Estimulação Elétrica , Eletrofisiologia , Imunofluorescência , Gânglios Parassimpáticos/citologia , Gânglios Parassimpáticos/efeitos dos fármacos , Cobaias , Masculino , Membranas/efeitos dos fármacos , Terminações Nervosas/efeitos dos fármacos , Sistema Nervoso Parassimpático/citologia , Técnicas de Patch-Clamp , Reflexo/efeitos dos fármacos , Substância P/metabolismo , Substância P/fisiologia
8.
Arthritis Res Ther ; 20(1): 47, 2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-29544534

RESUMO

BACKGROUND: The study aimed to assess 52-week efficacy and safety of secukinumab self-administration by autoinjector in patients with active psoriatic arthritis (PsA) in the FUTURE 3 study ( ClinicalTrials.gov NCT01989468). METHODS: Patients (≥ 18 years of age; N = 414) with active PsA were randomized 1:1:1 to subcutaneous (s.c.) secukinumab 300 mg, 150 mg, or placebo at baseline, weeks 1, 2, 3, and 4, and every 4 weeks thereafter. Per clinical response, placebo-treated patients were re-randomized to s.c. secukinumab 300 or 150 mg at week 16 (nonresponders) or week 24 (responders) and stratified at randomization by prior anti-tumor necrosis factor (TNF) therapy (anti-TNF-naïve, 68.1%; intolerant/inadequate response (anti-TNF-IR), 31.9%). The primary endpoint was the proportion of patients achieving at least 20% improvement in American College of Rheumatology response criteria (ACR20) at week 24. Autoinjector usability was evaluated by Self-Injection Assessment Questionnaire (SIAQ). RESULTS: Overall, 92.1% (300 mg), 91.3% (150 mg), and 93.4% (placebo) of patients completed 24 weeks, and 84.9% (300 mg) and 79.7% (150 mg) completed 52 weeks. In the overall population (combined anti-TNF-naïve and anti-TNF-IR), ACR20 response rate at week 24 was significantly higher in secukinumab groups (300 mg, 48.2% (p < 0.0001); 150 mg, 42% (p < 0.0001); placebo, 16.1%) and was sustained through 52 weeks. SIAQ results showed that more than 93% of patients were satisfied/very satisfied with autoinjector usage. Secukinumab was well tolerated with no new or unexpected safety signals reported. CONCLUSIONS: Secukinumab provided sustained improvements in signs and symptoms in active PsA patients through 52 weeks. High acceptability of autoinjector was observed. The safety profile was consistent with that reported previously. TRIAL REGISTRATION: ClinicalTrials.gov NCT01989468 . Registered 21 November 2013. EudraCT 2013-004002-25 . Registered 17 December 2013.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Artrite Psoriásica/diagnóstico , Artrite Psoriásica/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Adulto , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Método Duplo-Cego , Sistemas de Liberação de Medicamentos/efeitos adversos , Feminino , Cefaleia/induzido quimicamente , Humanos , Injeções Subcutâneas , Masculino , Pessoa de Meia-Idade , Nasofaringite/induzido quimicamente , Autoadministração , Resultado do Tratamento
9.
Respir Physiol Neurobiol ; 155(1): 55-63, 2007 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-16616710

RESUMO

Airway injury in infant monkeys exposed to ozone and/or house dust mite allergen (HDMA) is associated with a loss of epithelial innervation. In this study, we evaluated for persistence/recovery of the altered epithelial innervation. Thirty-day-old rhesus monkeys were exposed to repeated episodes of HDMA and/or ozone from 1 to 6 months of age and subsequently allowed to recover for 6 months in the absence of further ozone exposure and/or minimal HDMA challenge (sufficient to maintain allergen sensitization). At 1 year of age, nerve density in intrapulmonary airways was immunohistochemically evaluated using antibodies directed against protein gene product 9.5. Hyperinnervation and irregular epithelial nerve distribution was observed in both HDMA- and ozone-exposed groups; most prominent alterations were observed in animals exposed to HDMA plus ozone. Therefore, while adaptive mechanisms exist that re-establish epithelial innervation following cessation or diminution of exposure to HDMA and/or ozone, the recovery is associated with persistent proliferative mechanisms that result in hyperinnervation of the airways.


Assuntos
Alérgenos/toxicidade , Hipersensibilidade/fisiopatologia , Pulmão/efeitos dos fármacos , Pulmão/inervação , Oxidantes Fotoquímicos/toxicidade , Ozônio/toxicidade , Animais , Epitélio/efeitos dos fármacos , Epitélio/inervação , Imuno-Histoquímica , Macaca mulatta , Masculino , Microscopia Confocal , Pyroglyphidae/imunologia
10.
High Alt Med Biol ; 6(4): 289-300, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16351563

RESUMO

We examined the effect of dietary supplementation with L-arginine on breath condensate VEGF, exhaled nitric oxide (NO), plasma erythropoietin, symptoms of acute mountain sickness, and respiratory related sensations at 4,342 m through the course of 24 h in seven healthy male subjects. Serum L-arginine levels increased in treated subjects at time 0, 8, and 24 h compared with placebo, indicating the effectiveness of our treatment. L-arginine had no significant effect on overall Lake Louise scores compared with placebo. However, there was a significant increase in headache within the L-arginine treatment group at 12 h compared with time 0, a change not seen in the placebo condition between these two time points. There was a trend (p = 0.087) toward greater exhaled NO and significant increases in breath condensate VEGF with L-arginine treatment, but no L-arginine effect on serum EPO. These results suggest that L-arginine supplementation increases HIF-1 stabilization in the lung, possibly through a NO-dependent pathway. In total, our observations indicate that L-arginine supplementation is not beneficial in the prophylactic treatment of AMS.


Assuntos
Doença da Altitude/tratamento farmacológico , Arginina/administração & dosagem , Cefaleia/tratamento farmacológico , Óxido Nítrico/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Adulto , Doença da Altitude/metabolismo , Doença da Altitude/prevenção & controle , Análise de Variância , Testes Respiratórios/métodos , Estudos Cross-Over , Relação Dose-Resposta a Droga , Método Duplo-Cego , Cefaleia/etiologia , Cefaleia/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade
11.
Physiol Meas ; 31(9): 1147-59, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20664162

RESUMO

The release of small intestinal hormones by constituents of ingested food, such as fatty acids, is integral to post-prandial responses that reduce food intake. Recent evidence suggests that small intestinal electrical stimulation reduces food intake, although the mechanism of action is debated. To test the hypothesis that intestinal stimulation directly alters hormone release locally we used isolated rat distal ileum and measured glucagon-like peptide-1 (GLP-1) released in the presence or absence of linoleic acid (LA) and electrical field stimulation (EFS). Intact segments were oriented longitudinally between bipolar stimulating electrodes in organ bath chambers containing modified Krebs-Ringers bicarbonate (KRB) buffer including protease inhibitors. Incubation in LA (3 mg ml(-1)) for 45 min increased GLP-1 concentration (21.9 +/- 2.6 pM versus KRB buffer alone 3.6 +/- 0.1 pM). Eleven electrical stimulation conditions were tested. In the presence of LA none of the stimulation conditions inhibited LA-evoked GLP-1 release, whereas two high frequency short pulse widths (14 V, 20 Hz, 5 ms and 14 V, 40 Hz, 5 ms) and one low frequency long pulse width (14 V, 0.4 Hz, 300 ms) EFS conditions enhanced LA-evoked GLP-1 release by >250%. These results are consistent with a local effect of intestinal electrical stimulation to enhance GLP-1 release in response to luminal nutrients in the intestines. Enhancing hormone release could improve the efficacy of intestinal electrical stimulation and provide a potential treatment for obesity and metabolic conditions.


Assuntos
Alimentos , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Íleo/metabolismo , Animais , Estimulação Elétrica , Motilidade Gastrointestinal/fisiologia , Íleo/fisiologia , Técnicas In Vitro , Vias Neurais/fisiologia , Ratos , Ratos Sprague-Dawley
12.
Toxicol Pathol ; 35(1): 97-110, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17325978

RESUMO

UNLABELLED: The recent, dramatic increase in the incidence of childhood asthma suggests a role for environmental contaminants in the promotion of interactions between allergens and the respiratory system of young children. To establish whether exposure to an environmental stressor, ozone (O3), and an allergen, house dust mite (HDMA), during early childhood promotes remodeling of the epithelial-mesenchymal trophic unit (EMTU) of the tracheobronchial airway wall by altering postnatal development, infant rhesus monkeys were exposed to cyclic episodes of filtered air (FA), HDMA, O3, or HDMA plus O3. The following alterations in the EMTU were found after exposure to HDMA, O3, or HDMA plus O3: (1) reduced airway number; (2) hyperplasia of bronchial epithelium; (3) increased mucous cells; (4) shifts in distal airway smooth muscle bundle orientation and abundance to favor hyperreactivity; (5) interrupted postnatal basement membrane zone differentiation; (6) modified epithelial nerve fiber distribution; and (7) reorganization of the airway vascular and immune system. CONCLUSIONS: cyclic challenge of infants to toxic stress during postnatal lung development modifies the EMTU. This exacerbates the allergen response to favor development of intermittent airway obstruction associated with wheeze. And, exposure of infants during early postnatal lung development initiates compromises in airway growth and development that persist or worsen as growth continues, even with cessation of exposure.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Alérgenos/efeitos adversos , Asma/etiologia , Brônquios/efeitos dos fármacos , Desenvolvimento Infantil/efeitos dos fármacos , Crescimento e Desenvolvimento/efeitos dos fármacos , Poluentes Atmosféricos/imunologia , Alérgenos/imunologia , Animais , Asma/imunologia , Asma/prevenção & controle , Brônquios/crescimento & desenvolvimento , Brônquios/fisiopatologia , Criança , Desenvolvimento Infantil/fisiologia , Dermatophagoides farinae/imunologia , Modelos Animais de Doenças , Humanos , Exposição por Inalação , Macaca mulatta , Oxidantes Fotoquímicos/efeitos adversos , Ozônio/efeitos adversos
13.
Am J Physiol Lung Cell Mol Physiol ; 282(4): L775-81, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11880304

RESUMO

In the vagal-sensory system, neuropeptides such as substance P and calcitonin gene-related peptide (CGRP) are synthesized nearly exclusively in small-diameter nociceptive type C-fiber neurons. By definition, these neurons are designed to respond to noxious or tissue-damaging stimuli. A common feature of visceral inflammation is the elevation in production of sensory neuropeptides. Little is known, however, about the physiological characteristics of vagal sensory neurons induced by inflammation to produce substance P. In the present study, we show that allergic inflammation of guinea pig airways leads to the induction of substance P and CGRP production in large-diameter vagal sensory neurons. Electrophysiological and anatomical evidence reveals that the peripheral terminals of these neurons are low-threshold Adelta mechanosensors that are insensitive to nociceptive stimuli such as capsaicin and bradykinin. Thus inflammation causes a qualitative change in chemical coding of vagal primary afferent neurons. The results support the hypothesis that during an inflammatory reaction, sensory neuropeptide release from primary afferent nerve endings in the periphery and central nervous system does not require noxious or nociceptive stimuli but may also occur simply as a result of stimulation of low-threshold mechanosensors. This may contribute to the heightened reflex physiology and pain that often accompany inflammatory diseases.


Assuntos
Alveolite Alérgica Extrínseca/metabolismo , Pulmão/imunologia , Pulmão/inervação , Neurônios Aferentes/metabolismo , Substância P/metabolismo , Adaptação Fisiológica/imunologia , Animais , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Capsaicina/farmacologia , Cobaias , Pulmão/metabolismo , Masculino , Mecanorreceptores/imunologia , Mecanorreceptores/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Fibras Nervosas/imunologia , Fibras Nervosas/metabolismo , Proteínas de Neurofilamentos/análise , Neurônios Aferentes/química , Neurônios Aferentes/imunologia , Gânglio Nodoso/citologia
14.
Am J Physiol Lung Cell Mol Physiol ; 284(4): L581-7, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12618420

RESUMO

In vitro antigen challenge has multiple effects on the excitability of guinea pig bronchial parasympathetic ganglion neurons, including depolarization, causing phasic neurons to fire with a repetitive action potential pattern and potentiating synaptic transmission. In the present study, guinea pigs were passively sensitized to the antigen ovalbumin. After sensitization, the bronchi were prepared for in vitro electrophysiological intracellular recording of parasympathetic ganglia neurons to investigate the contribution of cyclooxygenase activation and prostanoids on parasympathetic nerve activity. Cyclooxygenase inhibition with either indomethacin or piroxicam before in vitro antigen challenge blocked the change in accommodation. These cyclooxygenase inhibitors also blocked the release of prostaglandin D(2) (PGD(2)) from bronchial tissue during antigen challenge. We also determined that PGE(2) and PGD(2) decreased the duration of the action potential after hyperpolarization, whereas PGF(2alpha) potentiated synaptic transmission. Thus prostaglandins released during antigen challenge have multiple effects on the excitability of guinea pig bronchial parasympathetic ganglia neurons, which may consequently affect the output from these neurons and thereby alter parasympathetic tone in the lower airways.


Assuntos
Brônquios/inervação , Gânglios Parassimpáticos/fisiologia , Prostaglandina-Endoperóxido Sintases/metabolismo , Prostaglandinas/metabolismo , Potenciais de Ação/efeitos dos fármacos , Animais , Asma/metabolismo , Asma/fisiopatologia , Broncoconstrição/fisiologia , Inibidores de Ciclo-Oxigenase/farmacologia , Dinoprosta/metabolismo , Dinoprosta/farmacologia , Dinoprostona/metabolismo , Dinoprostona/farmacologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Cobaias , Indometacina/farmacologia , Masculino , Ovalbumina/farmacologia , Piroxicam/farmacologia , Prostaglandina D2/metabolismo , Prostaglandina D2/farmacologia , Prostaglandinas/farmacologia , Transmissão Sináptica/fisiologia
15.
Am J Physiol Heart Circ Physiol ; 282(5): H1615-24, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11959623

RESUMO

A single bout of exercise results in a postexercise hypotension (PEH) that is accompanied by a reduced baroreflex function. Based on the role of rostral ventrolateral medulla (RVLM) neurons in controlling sympathetic nerve activity (SNA) and blood pressure, the role of gamma-aminobutyric acid (GABA) in controlling RVLM neuronal activity, and the reduced baroreflex-SNA relationship during PEH, we determined whether: 1) RVLM neuronal activity is decreased during PEH, 2) GABA(A)-receptor mechanisms mediate the decrease, and 3) baroreflex control of RVLM activity is reduced. Spontaneously hypertensive rats (SHR) were subjected to 40 min of treadmill or sham exercise (Sham PEH). PEH lasted 10 h in conscious and anesthetized SHR, indicating that the anesthetics did not affect the expression of PEH. Extracellular RVLM neuronal activity having a cardiac and sympathetic rhythm, lumbar SNA, and blood pressure were recorded at rest and during baroreflex function curves. Resting RVLM neuronal activity was lower and was increased to a greater extent by GABA(A)-receptor antagonism in PEH versus Sham PEH (P < 0.05). Baroreflex control of RVLM neuronal activity operated with a reduced gain (P < 0.05). Thus increased GABA signaling at RVLM neurons may contribute to PEH.


Assuntos
Hipotensão/etiologia , Bulbo/fisiopatologia , Neurônios/fisiologia , Esforço Físico , Receptores de GABA-A/fisiologia , Sistema Nervoso Simpático/fisiopatologia , Animais , Barorreflexo/fisiologia , Bicuculina/farmacologia , Pressão Sanguínea , Agonistas GABAérgicos/farmacologia , Antagonistas GABAérgicos/farmacologia , Antagonistas de Receptores de GABA-A , Hipotensão/fisiopatologia , Masculino , Muscimol/farmacologia , Distribuição Aleatória , Ratos , Ratos Endogâmicos SHR , Transdução de Sinais , Ácido gama-Aminobutírico/fisiologia
16.
Am J Physiol Regul Integr Comp Physiol ; 283(2): R320-30, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12121843

RESUMO

Neurokinin-containing nerve fibers were localized to guinea pig airway parasympathetic ganglia in control tissues but not in tissues pretreated with capsaicin. The purpose of the present study was to determine whether neurokinins, released during axonal reflexes or after antidromic afferent nerve stimulation, modulate ganglionic synaptic neurotransmission. The neurokinin type 3 (NK(3)) receptor antagonists SB-223412 and SR-142801 inhibited vagally mediated cholinergic contractions of bronchi in vitro at stimulation voltages threshold for preganglionic nerve activation but had no effect on vagally mediated contractions evoked at optimal voltage or field stimulation-induced contractions. Intracellular recordings from the ganglia neurons revealed that capsaicin-sensitive nerve stimulation potentiated subsequent preganglionic nerve-evoked fast excitatory postsynaptic potentials. This effect was mimicked by the NK(3) receptor agonist senktide analog and blocked by SB-223412. In situ, senktide analog markedly increased baseline tracheal cholinergic tone, an effect that was reversed by atropine and prevented by vagotomy or SB-223412. Comparable effects of intravenous senktide analog on pulmonary insufflation pressure were observed. These data highlight the important integrative role played by parasympathetic ganglia and indicate that activation of NK(3) receptors in airway ganglia by endogenous neurokinins facilitates synaptic neurotransmission.


Assuntos
Brônquios/inervação , Gânglios Parassimpáticos/fisiologia , Substância P/análogos & derivados , Transmissão Sináptica/fisiologia , Traqueia/inervação , Nervo Vago/fisiologia , Animais , Brônquios/efeitos dos fármacos , Broncoconstrição/efeitos dos fármacos , Broncoconstrição/fisiologia , Estimulação Elétrica , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Cobaias , Imuno-Histoquímica , Técnicas In Vitro , Masculino , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Fragmentos de Peptídeos/farmacologia , Piperidinas/farmacologia , Quinolinas/farmacologia , Receptores da Neurocinina-3/agonistas , Receptores da Neurocinina-3/antagonistas & inibidores , Substância P/metabolismo , Substância P/farmacologia , Transmissão Sináptica/efeitos dos fármacos , Traqueia/efeitos dos fármacos , Vagotomia , Nervo Vago/efeitos dos fármacos
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