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2.
J Hosp Infect ; 144: 111-117, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38159727

RESUMO

BACKGROUND: Vascular access devices form an essential component in the management of acute and chronic medical conditions. Introduction and ongoing management of these devices are linked with bundles of care aimed at reducing associated risks including bleeding and infection. AIM: To evaluate the antimicrobial potential of the potassium ferrate haemostatic disc on Gram-positive (Staphylococcus aureus) and Gram-negative (Klebsiella pneumoniae, Pseudomonas aeruginosa) bacteria and on Candida albicans. METHODS: The impact of the potassium ferrate disc was compared with the often-used chlorhexidine gluconate (CHG) impregnated disc to evaluate the potential efficacy of the potassium ferrate disc as an alternative to CHG in cases with an increased risk of active bleeding. RESULTS: In the presence of anticoagulated blood, we observed an inhibitory effect of the haemostatic disc on microbial growth for microbial strains commonly associated with vascular access device related infections. CONCLUSION: Our results indicate that the potassium ferrate disc may provide dual clinical benefits with both haemostatic and antimicrobial action observed during in-vitro testing.


Assuntos
Anti-Infecciosos Locais , Anti-Infecciosos , Infecções Relacionadas a Cateter , Cateterismo Venoso Central , Hemostáticos , Compostos de Ferro , Compostos de Potássio , Sepse , Humanos , Cateterismo Venoso Central/efeitos adversos , Hemostáticos/farmacologia , Clorexidina/farmacologia , Anti-Infecciosos/farmacologia , Sepse/etiologia , Infecções Relacionadas a Cateter/microbiologia
3.
Control Clin Trials ; 22(4): 405-19, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11514041

RESUMO

Although the beneficial effects of treatment with inhaled steroids in asthma are widely accepted, the role of early intervention in patients with mild asthma remains unsettled. Conventional efficacy trials are often of short duration and involve highly selected patient populations that exclude many patients typical of those encountered in routine clinical practice. Hence, a large "real-world" effectiveness study is needed to evaluate the benefits of early intervention with inhaled steroids in patients with mild, persistent asthma. In the START (inhaled Steroid Treatment As Regular Therapy in early asthma) study, patients ages 6-60 years, from 31 countries and districts worldwide with mild persistent asthma, have been randomized to once-daily treatment with budesonide, 200 microg (for patients < 11 years) or 400 microg (for patients > or = 11 years), or placebo via Turbuhaler for 3 years. The double-blind treatment period will be followed by a 2-year period of open budesonide treatment. Throughout the study, other asthma medication including glucocorticosteroids can be given as judged appropriate by the investigator. Lung function will be measured by spirometry using standardized techniques at 3-month intervals throughout the study, and bronchodilator reversibility will be measured annually. The primary outcome measures are the time to the first severe asthma-related event during the first 3 years of the study and the change in postbronchodilator forced expiratory volume in 1 second (FEV(1)) from baseline during the entire 5-year study period. These measures have been chosen to reflect the progression of mild asthma toward more severe asthma and the extent of irreversible airflow limitation, which should reflect the degree of airway remodeling.


Assuntos
Anti-Inflamatórios/uso terapêutico , Asma/tratamento farmacológico , Budesonida/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Projetos de Pesquisa , Doença Aguda , Administração Tópica , Adolescente , Adulto , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/efeitos adversos , Asma/diagnóstico , Budesonida/administração & dosagem , Budesonida/efeitos adversos , Criança , Método Duplo-Cego , Seguimentos , Glucocorticoides , Humanos , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Nebulizadores e Vaporizadores , Avaliação de Resultados em Cuidados de Saúde/métodos , Distribuição Aleatória , Testes de Função Respiratória , Tamanho da Amostra , Estatística como Assunto
5.
Respir Med ; 95(6): 505-12, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11421509

RESUMO

The FACET (Formoterol and Corticosteroid Establishing Therapy) study established that there is a clear clinical benefit in adding formoterol to budesonide therapy in patients who have persistent symptoms of asthma despite treatment with low to moderate doses of an inhaled corticosteroid. We combined the clinical results from the FACET study with an expert survey on average resource use in connection with mild and severe asthma exacerbations in the U.K., Sweden and Spain. The primary objective of this study was to assess the health economics of adding the inhaled long-acting beta2-agonist formoterol to the inhaled corticosteroid budesonide in the treatment of asthma. The extra costs of adding the inhaled beta2-agonist formoterol to the corticosteroid budesonide in asthmatic patients in Sweden were offset by savings from reduced use of resources for exacerbations. For Spain the picture was mixed. Adding formoterol to low dose budesonide generated savings, whereas for moderate doses of budesonide about 75% of the extra formoterol costs could be recouped. In the U.K., other savings offset about half of the extra cost of formoterol. All cost-effectiveness ratios are within accepted cost-effectiveness ranges reported from previous studies. If productivity losses were included, there were net savings in all three countries, ranging from Euro 267-1183 per patient per year. In conclusion, adding the inhaled, long-acting beta2-agonist formoterol to low-moderate doses of the inhaled corticosteroid budesonide generated significant gains in all outcome measures with partial or complete offset of costs. Adding formoterol to budesonide can thus be considered to be cost-effective.


Assuntos
Antiasmáticos/economia , Asma/economia , Budesonida/economia , Etanolaminas/economia , Doença Aguda , Adolescente , Adulto , Idoso , Antiasmáticos/uso terapêutico , Asma/tratamento farmacológico , Budesonida/uso terapêutico , Redução de Custos , Análise Custo-Benefício , Quimioterapia Combinada , Etanolaminas/uso terapêutico , Fumarato de Formoterol , Custos de Cuidados de Saúde , Humanos , Pessoa de Meia-Idade , Distribuição Normal , Espanha , Suécia , Reino Unido
6.
Eur Respir J ; 14(5): 1038-43, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10596687

RESUMO

The Formoterol and Corticosteroids Establishing Therapy (FACET) study has provided the first opportunity to examine the long-term effects of inhaled steroids and long-acting beta2-agonists on asthma-specific quality of life. The objectives of the present study were to: evaluate the effects of long-term (1 yr) formoterol and increasing doses of budesonide on asthma quality of life; 2) to determine whether initial improvements in quality of life are sustained when improvements in clinical indices persist; and 3) to evaluate the long-term relationship between changes in clinical indices and changes in quality of life. Of the 852 asthmatic adults enrolled, 470 from five countries participated in this quality of life evaluation. After a 4-week run-in on 1,600 microg budesonide, patients were randomized to either 200 microg (Bud200) or 800 microg budesonide (Bud800) in combination with either 24 microg formoterol (F) or placebo daily for 1 yr. The Asthma Quality of Life Questionnaire (AQLQ) was completed and conventional clinical indices measured at enrolment and randomization and on seven occasions during the following 12 months. During the run-in, there was an improvement in AQLQ score (changes (delta) in overall score approximately 0.50; p<0.0001). After randomization, there was a further improvement in the Bud800+F group (delta=0.21; p=0.028). One month post-randomization, improvements in all groups stabilized and were sustained throughout the 12 months in a pattern very similar to that observed for the conventional clinical indices. The correlation of individual patient changes in clinical indices and changes in AQLQ score during the 12-month randomized period were weak to moderate (maximum r=0.51). Improvements in quality of life, which were greatest in the 800 microg budesonide plus 24 microg formoterol group, were sustained throughout the 12 months in a similar manner to the clinical indices. Long-term changes in conventional clinical indices cannot be used to predict the effect of treatment on individual patient experience.


Assuntos
Agonistas Adrenérgicos beta/administração & dosagem , Asma/tratamento farmacológico , Broncodilatadores/administração & dosagem , Budesonida/administração & dosagem , Etanolaminas/administração & dosagem , Qualidade de Vida , Agonistas Adrenérgicos beta/uso terapêutico , Adulto , Asma/psicologia , Broncodilatadores/uso terapêutico , Budesonida/uso terapêutico , Método Duplo-Cego , Etanolaminas/uso terapêutico , Feminino , Fumarato de Formoterol , Humanos , Masculino , Avaliação de Resultados em Cuidados de Saúde/métodos , Inquéritos e Questionários , Fatores de Tempo
7.
Am J Respir Crit Care Med ; 160(2): 594-9, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10430734

RESUMO

The identification, prevention, and prompt treatment of exacerbations are major objectives of asthma management. We looked at change in PEF, symptoms, and use of rescue beta-agonists during the 425 severe exacerbations that occurred during a 12-mo parallel group study (FACET) in which low and high doses of budesonide with and without formoterol were compared in patients with asthma. Oral corticosteroids were prescribed for severe exacerbations, the main study end point, defined as the need for a course of oral corticosteroids (n = 311) or a reduction in morning PEF of > 30% on two consecutive days. PEF, symptoms, and bronchodilator use over the 14 d before and after the exacerbation were obtained from diary cards. Exacerbations were characterized by a gradual fall in PEF over several days, followed by more rapid changes over 2 to 3 d; an increase in symptoms and rescue beta-agonist use occurred in parallel, and both the severity and time course of the changes were similar in all treatment groups. Exacerbations identified by the need for oral corticosteroids were associated with more symptoms and smaller changes in PEF than those identified on the basis of PEF criteria. Female sex was the main patient characteristic associated with an increased risk of having a severe exacerbation. Exacerbations may be characterized predominantly by change in symptoms or change in PEF, but the pattern was not affected by the dose of inhaled corticosteroid or by whether the patient was taking formoterol.


Assuntos
Broncoconstrição/efeitos dos fármacos , Broncodilatadores/administração & dosagem , Budesonida/administração & dosagem , Etanolaminas/administração & dosagem , Adolescente , Adulto , Idoso , Broncodilatadores/efeitos adversos , Budesonida/efeitos adversos , Preparações de Ação Retardada , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Quimioterapia Combinada , Etanolaminas/efeitos adversos , Volume Expiratório Forçado/efeitos dos fármacos , Fumarato de Formoterol , Humanos , Pessoa de Meia-Idade , Pico do Fluxo Expiratório/efeitos dos fármacos
10.
N Engl J Med ; 337(20): 1405-11, 1997 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-9358137

RESUMO

BACKGROUND: The role of long-acting, inhaled beta2-agonists in treating asthma is uncertain. In a double-blind study, we evaluated the effects of adding inhaled formoterol to both lower and higher doses of the inhaled glucocorticoid budesonide. METHODS: After a four-week run-in period of treatment with budesonide (800 microg twice daily), 852 patients being treated with glucocorticoids were randomly assigned to one of four treatments given twice daily by means of a dry-powder inhaler (Turbuhaler): 100 microg of budesonide plus placebo, 100 microg of budesonide plus 12 microg of formoterol, 400 microg of budesonide plus placebo, or 400 microg of budesonide plus 12 microg of formoterol. Terbutaline was permitted as needed. Treatment continued for one year; we compared the frequency of exacerbations of asthma, symptoms, and lung function in the four groups. A severe exacerbation was defined by the need for oral glucocorticoids or a decrease in the peak flow to more than 30 percent below the base-line value on two consecutive days. RESULTS: The rates of severe and mild exacerbations were reduced by 26 percent and 40 percent, respectively, when formoterol was added to the lower dose of budesonide. The higher dose of budesonide alone reduced the rates of severe and mild exacerbations by 49 percent and 37 percent, respectively. Patients treated with formoterol and the higher dose of budesonide had the greatest reductions -- 63 percent and 62 percent, respectively. Symptoms of asthma and lung function improved with both formoterol and the higher dose of budesonide, but the improvements with formoterol were greater. CONCLUSIONS: In patients who have persistent symptoms of asthma despite treatment with inhaled glucocorticoids, the addition of formoterol to budesonide therapy or the use of a higher dose of budesonide may be beneficial. The addition of formoterol to budesonide therapy improves symptoms and lung function without lessening the control of asthma.


Assuntos
Agonistas Adrenérgicos beta/uso terapêutico , Asma/tratamento farmacológico , Broncodilatadores/uso terapêutico , Budesonida/uso terapêutico , Etanolaminas/uso terapêutico , Glucocorticoides/uso terapêutico , Administração por Inalação , Adolescente , Adulto , Idoso , Broncodilatadores/administração & dosagem , Budesonida/administração & dosagem , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Volume Expiratório Forçado/efeitos dos fármacos , Fumarato de Formoterol , Glucocorticoides/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Pico do Fluxo Expiratório/efeitos dos fármacos
11.
Eur Respir J ; 10(11): 2474-8, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9426081

RESUMO

Two studies are presented, with the aim of establishing the dose potency ratio for salbutamol given via Turbuhaler and via a pressurized metered-dose inhaler (pMDI). Both studies were of a double-blind, randomized design. Outpatients with mild-to-moderate chronic reversible airway obstruction were given single doses of salbutamol administered via Turbuhaler and via pMDI. Efficacy and safety variables were measured before and during 6 h after each dose. The first study was a four-way crossover study including 12 patients. The salbutamol doses given were: 50, 100 and 2x100 microg via Turbuhaler and 2x100 microg via pMDI (Ventolin). The study showed that 2x100 microg of salbutamol inhaled via Turbuhaler is more potent than 2x100 microg salbutamol inhaled via a pMDI, and that 100 microg salbutamol via Turbuhaler is at least as potent as 2x100 microg salbutamol inhaled via a pMDI. The second study including 50 patients was a placebo-controlled five-way crossover, study. Two doses of salbutamol via Turbuhaler, 50 and 2x100 microg, and via pMDI, 100 and 2x200 microg, were given. There was a dose-dependent response in forced expiratory volume in one second (FEV1) for both inhalers. Adjusted for differences in baseline FEV1 values, the estimated relative dose potency for Turbuhaler versus pMDI was 1.98:1 (95% confidence interval 12-3.2). These studies showed that the same bronchodilating effect can be achieved when half the dose of salbutamol given via a conventional pressurized metered-dose inhaler is given via Turbuhaler.


Assuntos
Albuterol/administração & dosagem , Asma/tratamento farmacológico , Broncodilatadores/administração & dosagem , Nebulizadores e Vaporizadores , Administração por Inalação , Albuterol/farmacologia , Asma/fisiopatologia , Broncodilatadores/farmacologia , Estudos Cross-Over , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Pessoa de Meia-Idade
12.
Allergy ; 51(10): 745-8, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8905004

RESUMO

Formoterol administered by a dry-powder (DP) capsule inhaler was compared with a pressurized metered-dose inhaler (pMDI) with regard to bronchodilating and systemic effects. The study used a double-blind, crossover, double-dummy technique. Twelve patients with moderate reversible asthma in a stable phase were examined on two separate study days, and the inhalers were given in randomized order. After baseline measurements, increasing doses of formoterol were given at intervals of 75 min. FEV1 and heart rate and tremor measurements were repeated after each dose, and the doses were 12 + 12 + 24 + 48 micrograms, giving a total dose of 96 micrograms. The peak expiratory flow rate (PEFR) was recorded in the morning before the first dose, after the last dose, and then repeatedly at home until 19 h after the last dose. There was an equal increase in ventilatory capacity at each dose level, independent of inhaler device. Repeated PEFR measurements after the last dose did not reveal any differences in duration of effect. There was a slight but statistically significant increase in heart rate and tremor after the highest doses of the DP formulation compared to the pMDI. These systemic effects can probably be explained by the reduced oral deposition of the aerosol caused by using a spacer. This study indicates that the DP and pMDI formulations of formoterol are equipotent in bronchodilation.


Assuntos
Asma/tratamento farmacológico , Broncodilatadores/administração & dosagem , Etanolaminas/administração & dosagem , Nebulizadores e Vaporizadores , Administração por Inalação , Adulto , Idoso , Cápsulas , Estudos Cross-Over , Relação Dose-Resposta a Droga , Método Duplo-Cego , Fumarato de Formoterol , Humanos , Masculino , Pessoa de Meia-Idade , Pico do Fluxo Expiratório/efeitos dos fármacos , Pós , Equivalência Terapêutica , Fatores de Tempo
13.
Eur Respir J ; 9(7): 1427-32, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8836654

RESUMO

Studies using dry powder devices have suggested that fluticasone propionate (FP) has a greater systemic effect than budesonide (BUD). The aim of the present study was to investigate and compare the relative systemic potency of FP and BUD from their respective pressurized metered-dose inhalers (pMDIs). A placebo-controlled, open, randomized, cross-over study was conducted in 21 healthy male volunteers. Placebo, BUD (200, 400 and 1,000 micrograms b.i.d.) and FP (200, 375 and 1,000 micrograms b.i.d.) were inhaled for 4 days, with a wash-out period of at least 3 days between treatments. Blood samples for cortisol analysis were drawn during the last 24 h of each treatment period. Cortisol levels, measured as 24 h pooled plasma cortisol, were statistically significantly lower (p = 0.0001) for all dose levels during FP pMDI treatment (21, 39 and 84% suppression from placebo) than during BUD pMDI treatment (1, 3 and 27% suppression from placebo). The relative systemic potency FP:BUD was 3.7:1 (95% confidence interval (95% CI) 2.9-4.8)). The relative systemic potency based on the single 08:00 h samples was 5.2:1 (95% CI 3.0-9.3). In conclusion, in healthy male volunteers using pressurized metered-dose inhalers, fluticasone propionate was shown to have a stronger systemic effect than budesonide.


Assuntos
Androstadienos/administração & dosagem , Anti-Inflamatórios/administração & dosagem , Pregnenodionas/administração & dosagem , Administração por Inalação , Administração Tópica , Adulto , Aerossóis , Androstadienos/farmacologia , Anti-Inflamatórios/farmacologia , Budesonida , Estudos Cross-Over , Relação Dose-Resposta a Droga , Fluticasona , Humanos , Hidrocortisona/sangue , Masculino , Nebulizadores e Vaporizadores , Pregnenodionas/farmacologia , Radioimunoensaio
14.
Am J Med Genet ; 55(3): 311-4, 1995 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-7726228

RESUMO

Familial Mediterranean fever (FMF) is an autosomal recessive recurrent episodic inflammatory disorder that occurs with high frequency in certain populations in the Mediterranean area. Using extended pedigree data of 90 FMF probands, we calculated the FMF gene frequency in various ethnic groups in Israel by analyzing the frequency in a total of 2,312 first cousins. The heterozygote frequencies were as follows: 1:4.9 (0.2 +/- 0.06) for the Libyan subgroup, 1:6.4 (0.16 +/- 0.03) for the other North African countries subgroup, 1:13.3 (0.07 +/- 0.04) for the Iraqi subgroup, 1:11.4 (0.09 +/- 0.06) for the Ashkenazic subgroup, and 1:29.4 (0.03 +/- 0.03) for the remaining ethnic groups. The observed number of affected parents and offspring of the probands was in agreement with the estimated gene frequency. Thus, the FMF gene frequency is very high in all Jewish ethnic groups in Israel, especially those originating in North African countries. This also explains the parent-to-off-spring transmission of FMF reported in North-African Jews.


Assuntos
Febre Familiar do Mediterrâneo/etnologia , Judeus/genética , África do Norte/etnologia , Cromossomos Humanos Par 16 , Europa (Continente)/etnologia , Feminino , Frequência do Gene , Heterozigoto , Humanos , Iraque/etnologia , Israel/epidemiologia , Líbia/etnologia , Masculino , Epidemiologia Molecular , Turquia/etnologia
16.
Am J Med Genet ; 53(2): 172-5, 1994 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-7856643

RESUMO

To identify a specific heterozygote advantage in familial Mediterranean fever (FMF), responsible for the high carrier rate of 1/6 in North African Jews, we studied the morbidity and mortality of 148 parents of affected patients and of 148 ethnically matched control persons. Our data demonstrate an apparently reduced prevalence of asthma in the heterozygotes compared with the control persons (3 vs. 6). There were no significant differences between the 2 groups in fertility rate, number of pregnancies and deliveries, or the prevalence of common diseases. Our data are in agreement with previous studies which demonstrated decreased asthma prevalence in FMF patients. It further confirmed, these findings suggest that identification of the FMF gene on 16p may provide an insight into asthma.


Assuntos
Asma/genética , Asma/prevenção & controle , Febre Familiar do Mediterrâneo/genética , Adulto , África do Norte/etnologia , Idoso , Asma/epidemiologia , Cromossomos Humanos Par 16 , Febre Familiar do Mediterrâneo/epidemiologia , Feminino , Frequência do Gene , Heterozigoto , Humanos , Israel/epidemiologia , Judeus/genética , Masculino , Pessoa de Meia-Idade , Gravidez , Seleção Genética
17.
Adolescence ; 29(113): 1-11, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8036968

RESUMO

From a review of recent literature, support was found for the hypothesis that the power of an alcoholic parent within a household is related to whether offspring become alcoholic. In considering reasons for this relationship, it is suggested here that children and adolescents are more likely to emulate and identify with a powerful alcoholic parent and, through these processes, learn that alcohol can make them feel powerful.


Assuntos
Alcoolismo/psicologia , Filho de Pais com Deficiência/psicologia , Comportamento Imitativo , Desenvolvimento da Personalidade , Adolescente , Consumo de Bebidas Alcoólicas/genética , Consumo de Bebidas Alcoólicas/psicologia , Alcoolismo/genética , Feminino , Humanos , Masculino , Fatores de Risco
18.
Br J Pharmacol ; 109(3): 845-51, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8358575

RESUMO

1. We examined non-adrenergic, non-cholinergic (NANC) stimulation for its stabilizing effect on bronchial smooth-muscle tone with respect to its regulatory power and the effect of variations in neural impulse frequency. 2. The guinea-pig isolated main bronchus (n = 4-12) was pretreated with indomethacin (10 microM) and incubated with atropine (1 microM) and guanethidine (10 microM). Electrical field stimulation (EFS: 1200 mA, 0.5 ms, 240 s) was applied at various levels of tone prior to EFS: first without tone, then at a moderate tone induced by histamine (0.3 microM) and, finally, at a high tone induced by histamine (6 microM). Three different stimulation frequencies (1, 3 or 10 Hz) were used in order to produce moderate to near-maximum contractile and relaxant NANC neural responses. Both the contractile and the relaxant NANC responses were tetrodotoxin-sensitive in the guinea-pig isolated main bronchus (3 Hz). 3. Without tone prior to EFS, NANC activation (1, 3 or 10 Hz) induced a pronounced contractile response. At a moderate level of tone prior to EFS, NANC activation induced a less pronounced contractile response. At the highest level of tone prior to EFS, NANC activation induced a relaxant response. All these NANC responses adjusted the tone towards a similar level and this 'stabilization level' was 56(6)% at 1 Hz, 65(3)% at 3 Hz and 56(5)% at 10 Hz, expressed as a percentage of the maximum histamine-induced (0.1 mM) tone in each airway preparation. 4. There was a difference of approximately 90% of maximum between the highest and the lowest tone level prior to NANC activation. This difference was reduced by the converging contractile and relaxantNANC responses and the magnitude of this 'convergence effect' was 40(8)% at 1 Hz, 72(4)% at 3 Hz and 90(2)% at 10 Hz.5. These findings indicate that NANC neural activation stabilizes bronchial smooth-muscle tone via a contraction when the tone is low prior to activation and via a relaxation when the tone is high prior to activation. The NANC stabilizing effect on tone appears to be powerful and its magnitude can be controlled by the neural impulse frequency. The level of tone towards which the NANC responses converge does not appear to be markedly altered by variations in the impulse frequency. Our findings are consistent with a regulatory role for NANC responses in the control of bronchial smooth-muscle tone.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Músculo Liso/fisiologia , Animais , Brônquios/efeitos dos fármacos , Brônquios/inervação , Brônquios/fisiologia , Estimulação Elétrica , Feminino , Cobaias , Histamina/farmacologia , Técnicas In Vitro , Indometacina/farmacologia , Contração Muscular/fisiologia , Relaxamento Muscular/efeitos dos fármacos , Tono Muscular/efeitos dos fármacos , Tono Muscular/fisiologia , Músculo Liso/efeitos dos fármacos , Músculo Liso/inervação , Tetrodotoxina/farmacologia
19.
Thorax ; 48(5): 547-53, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-8100652

RESUMO

BACKGROUND: Formoterol and salmeterol are new long acting beta 2 adrenoceptor agonists. The maximum relaxant effect, potency and functional antagonism against carbachol induced contraction for salmeterol, formoterol and salbutamol have been compared in the guinea pig isolated trachea. In addition, the possibility of inducing a non-beta adrenoceptor mediated relaxation by salmeterol was studied. METHODS: Concentration response experiments were conducted with isolated tracheal preparations (n = 4-6 in all experiments), precontracted by carbachol to cause either 40% (60 nmol/l), 80% (0.3 mumol/l) or 100% (3 mumol/l, supramaximal) of the maximum contraction. Each beta agonist was added cumulatively at each level of precontraction. Additional cumulative concentration response experiments were conducted for salmeterol alone at the highest level of precontraction, with and without beta blockade by sotalol (1 mmol/l). With the drug concentrations which produced the maximum response and the highest level of precontraction, the relaxation of formoterol (10 nmol/l) and salmeterol (1 mumol/l) was also compared non-cumulatively. Finally, with the corresponding drug concentrations and precontraction, the relaxant effect was compared for formoterol (10 nmol/l) in salmeterol relaxed airways with that of salmeterol (1 mumol/l) in formoterol relaxed airways. RESULTS: The increase in carbachol concentration from 60 nmol/l to 3 mumol/l induced a rightward shift in the mean (SE) concentration (log steps) causing 50% maximum relaxation for salmeterol (0.73 (0.17)), formoterol (0.85 (0.18)), and salbutamol (1.13 (0.11)). Significant differences in the maximum relaxant effect were shown at the highest level of precontraction only, with a remaining active tension of percentage precontraction of 27% (4%) for 1 mumol/l salbutamol and 35% (3%) for 10 nmol/l formoterol compared with 50% (2%) for 1 mumol/l salmeterol. The rank order of potency was: formoterol > salbutamol approximately salmeterol at all levels of precontraction (-log EC50: 9.32 (0.05) for formoterol, 7.82 (0.08) for salbutamol, and 7.50 (0.13) for salmeterol at 80% maximum precontraction). Beta blockade by sotalol (1 mmol/l) significantly inhibited the relaxation induced by salmeterol (1 mumol/l) (remaining active tension: 104% (1%) v 71% (11%) of precontraction) but not the relaxation induced by salmeterol (10 mumol/l) (remaining active tension: 75% (5%) v 71% (12%) of precontraction). In the non-cumulative experiments, formoterol displayed more relaxant effect than salmeterol (remaining active tension: 51% (6%) v 65% (6%) of precontraction). Finally, formoterol significantly relaxed salmeterol relaxed airways (relaxant effect: 22% (8%) of precontraction) whereas there was no significant response to salmeterol in formoterol relaxed airways (relaxant effect: 5% (12%) of precontraction). CONCLUSIONS: In the guinea pig isolated trachea, formoterol and salbutamol produce more relaxant effect than salmeterol, suggesting that salmeterol is a partial beta 2 agonist. Very high concentrations of salmeterol may induce non-beta adrenoceptor mediated relaxation. Formoterol is more potent than both salbutamol and salmeterol. There is no pronounced difference in the magnitude of antagonism against carbachol induced contractions between salmeterol, formoterol, and salbutamol.


Assuntos
Agonistas Adrenérgicos beta/farmacologia , Albuterol/análogos & derivados , Albuterol/farmacologia , Etanolaminas/farmacologia , Traqueia/efeitos dos fármacos , Animais , Carbacol/farmacologia , Relação Dose-Resposta a Droga , Feminino , Fumarato de Formoterol , Cobaias , Relaxamento Muscular/efeitos dos fármacos , Xinafoato de Salmeterol , Sotalol/farmacologia
20.
Eur Respir J ; 6(3): 425-33, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8472834

RESUMO

In guinea-pig isolated airways, nonadrenergic, noncholinergic (NANC) neural responses converge towards a similar level of smooth muscle tone, via a contraction when the tone is low prior to stimulation, and via a relaxation when the tone is high prior to stimulation. We wanted to assess the effect of simultaneous parasympathetic activation on these converging NANC responses, with and without the addition of sympathetic activation. In guinea-pig isolated airways, the spontaneous airway tone was initially abolished by indomethacin (10 microM). In one series, adrenergic depletion by guanethidine (10 microM) was then established, with and without cholinergic blockade by atropine (1 microM). In another series, either cholinergic blockade by atropine (1 microM) or no blockade was utilized. Responses to electrical field stimulation (1,200 mA, 0.5 ms, 3 Hz for 240 s) were studied with no induced tone, at a moderate (0.3 microM) and at a near-maximum (6 microM), histamine-induced tone. The mean level of the tonus equilibrium (% of maximum tone) was higher with the simultaneous NANC and parasympathetic activation than with NANC activation alone (75% compared with 44%, in the main bronchus, n = 8). The level of the tonus equilibrium was also higher with the simultaneous NANC, sympathetic and parasympathetic activation than with NANC and sympathetic activation only (49% compared with 21%, in the main bronchus, n = 8). The pattern was similar in the distal trachea. In conclusion, NANC neural responses can stabilize smooth muscle tone, and this stabilizing effect can be modulated by both parasympathetic and sympathetic activation, in guinea-pig isolated airways.


Assuntos
Brônquios/inervação , Contração Muscular/fisiologia , Tono Muscular/fisiologia , Músculo Liso/inervação , Sistema Nervoso Parassimpático/fisiologia , Sistema Nervoso Simpático/fisiologia , Traqueia/inervação , Animais , Atropina/farmacologia , Estimulação Elétrica , Feminino , Guanetidina/farmacologia , Cobaias , Indometacina/farmacologia , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiologia
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