Reversion of methacholine induced bronchoconstriction with inhaled diazepam in patients with asthma / Bloqueo de la respuesta bronco constrictora a metacolina con diazepam inhalado en pacientes con asma

Background: Benzodiazepines have a direct bronchodilatory effect. Methacholine is a non-selective muscarinic receptor agonist causing bronchoconstriction. Aim: To examine the effects of inhaled benzodiazepines, modulating bronchoconstriction induced by methacholine in patients with asthma. Patients and Methods: Twelve patients with well controlled asthma were studied. On the first day, after determining the initial values of pulmonary function, a dose response curve was carried out with progressive doses of methacholine. After the last dose, when at least a 20% drop of the initial forced expiratory volume in the first second (FEV1) was achieved, vital capacity (VC) and FEV1 were measured at 7, 15 and 30 minutes after provocation. On the second day a diazepam aerosol was inhaled by the patients prior to the same protocol with methacholine. Results: In the first day of testing, methacholine inhalation (6 mg/mL) led to a significant drop in FEV1 from 2.98 to 1.69 L. On the second day of study, in the same patients, previous inhalation with diazepam reduced the changes of FEV1 after inhalation of methacholine. This parameter decreased from 2.48 to 2.21 L. Conclusions: Inhalation of benzodiazepines reduce bronchoconstriction after a methacholine challenge in patients with asthma.

Antecedentes: Las benzodiacepinas tienen un efecto broncodilatador directo. La metacolina es un agonista muscarínico que causa bronco constricción. Objetivo: Evaluar el efecto modulador de la inhalación de diazepam sobre la bronco constricción inducida por metacolina. Pacientes y Métodos: Se estudiaron 12 pacientes con asma bien controlada. En el primer día, se determinó la curva dosis respuesta de parámetros de función pulmonar a una dosis progresiva de metacolina. Después de la última dosis, cuando se consiguió un 20% de reducción en la capacidad vital forzada en el primer segundo (FEV1), se midió FEV1 y la capacidad vital (CV) a los 7, 15 y 30 min después de la provocación. En el segundo día los pacientes se inhalaron con diazepam antes de hacer la prueba con metacolina. Resultados: En el primer día, el FEV1 bajo de 2,98 a 1,69 l con 6 mg/ml de metacolina. En el segundo día, la inhalación de diazepam redujo la respuesta a metacolina con una reducción de FEV1 de 2,48 a 2,21 L. Conclusiones: La benzodiacepinas reducen la respuesta de vasoconstricción a metacolina.

Medicinas tradicionales andinas y su despenalización: entrevista con Walter Álvarez Quispe / Decriminalizing traditional Andean medicine: an interview with Walter Álvarez Quispe

Walter Álvarez Quispe, terapeuta kallawaya y biomédico especializado en cirugía general y ginecología, presenta la lucha de los terapeutas tradicionales y alternativos por la depenalización de estos sistemas médicos andinos realizada entre 1960 y 1990. Bolivia se torna el primer país en América Latina y el Caribe en despenalizar la medicina tradicional antes de los planteamientos de la Conferencia Internacional sobre Atención Primaria de Salud (Alma-Ata, 1978). Los datos aportados por el entrevistado aseguran que los logros alcanzados, principalmente por los kallawayas, responden a un proyecto propio y autónomo. Estas conquistas no se deben a las políticas oficiales de interculturalidad en salud, aunque busquen atribuirse para sí los logros alcanzados.

Walter Álvarez Quispe, a Kallawaya healer and biomedical practitioner specializing in general surgery and gynecology, presents the struggle of traditional and alternative healers to get their Andean medical systems depenalized between 1960 and 1990. Bolivia was the first country in Latin America and the Caribbean to decriminalize traditional medicine before the proposals of the International Conference on Primary Health Care (Alma-Ata, 1978). The data provided by the interviewee show that the successes achieved, mainly by the Kallawayas, stem from their own independent initiative. These victories are not the result of official policies of interculturality in healthcare, although the successes achieved tend to be ascribed to them.

The effects of pycnogenol on antioxidant enzymes in a mouse model of ozone exposure

BACKGROUND/AIMS: Ozone is an environmentally reactive oxidant, and pycnogenol is a mixture of flavonoid compounds extracted from pine tree bark that have antioxidant activity. We investigated the effects of pycnogenol on reactive nitrogen species, antioxidant responses, and airway responsiveness in BALB/c mice exposed to ozone. METHODS: Antioxidant levels were determined using high performance liquid chromatography with electrochemical detection. Nitric oxide (NO) metabolites in bronchoalveolar lavage (BAL) fluid from BALB/c mice in filtered air and 2 ppm ozone with pycnogenol pretreatment before ozone exposure (n = 6) were quantified colorimetrically using the Griess reaction. RESULTS: Uric acid and ascorbic acid concentrations were significantly higher in BAL fluid following pretreatment with pycnogenol, whereas gamma-tocopherol concentrations were higher in the ozone exposed group but were similar in the ozone and pycnogenol pretreatment groups. Retinol and gamma-tocopherol concentrations tended to increase in the ozone exposure group but were similar in the ozone and pycnogenol pretreatment groups following ozone exposure. Malonylaldehyde concentrations increased in the ozone exposure group but were similar in the ozone and pycnogenol plus ozone groups. The nitrite and total NO metabolite concentrations in BAL fluid, which parallel the in vivo generation of NO in the airways, were significantly greater in the ozone exposed group than the group exposed to filtered air, but decreased with pycnogenol pretreatment. CONCLUSIONS: Pycnogenol may increase levels of antioxidant enzymes and decrease levels of nitrogen species, suggesting that antioxidants minimize the effects of acute ozone exposure via a protective mechanism.

Baixo grau de percepção da dispneia após teste de broncoprovocação induzida por metacolina em pacientes com asma / Poor perception of dyspnea following methacholine challenge test in patients with asthma

OBJETIVO: Determinar o percentual de asmáticos com má percepção da dispneia, correlacionando-a com gravidade da broncoconstrição aguda, hiper-responsividade brônquica, uso de medicação de manutenção e controle da asma. MÉTODOS: Ensaio clínico não controlado com pacientes asmáticos do Ambulatório de Pneumologia do Hospital São Lucas em Porto Alegre (RS). Foram realizados testes de broncoprovocação com metacolina com protocolo dosimetrado em cinco doses, e foi avaliada a percepção da dispneia após cada dose administrada, utilizando a escala de Borg. Dados sobre controle da asma, medicação em uso e uso de broncodilatador de curta ação de resgate foram coletados. RESULTADOS: Dos 65 pacientes incluídos, 53 completaram a avaliação. Desses, 32 (60,5 por cento) apresentaram percepção adequada da dispneia após o teste de broncoprovocação com metacolina, ao passo que 21 (39,5 por cento) não perceberam nenhuma alteração no grau de dispneia mesmo após uma queda de 20 por cento em VEF1. Não houve diferenças significativas entre os dois grupos em relação a VEF1 basal, percentagem de queda do VEF1 e dose de metacolina causadora de queda de 20 por cento do VEF1. Não houve correlação significativa entre percepção da dispneia e idade (p = 0,247), sexo (p = 0,329), uso de medicação de manutenção (p = 0,152), controle da asma (p = 0,562), hiper-responsividade brônquica (p = 0,082) e gravidade da broncoconstrição aguda (p = 0,749). CONCLUSÕES: Uma percentagem significativa dos asmáticos apresenta baixo grau de percepção da dispneia. Os fatores relacionados com a incapacidade de identificação da modificação da função pulmonar não estão bem definidos. A identificação e a orientação desse grupo de pacientes são fundamentais para a redução de morbidade e mortalidade por asma.

OBJECTIVE: To determine the proportion of asthma patients with a poor perception of dyspnea, correlating the level of that perception with the severity of acute bronchoconstriction, bronchial hyperresponsiveness, use of maintenance medication, and asthma control. METHODS: Uncontrolled clinical trial involving asthma patients treated at the Pulmonology Outpatient Clinic of the São Lucas Hospital, in Porto Alegre , Brazil. Methacholine challenge testing was performed using a five-breath dosimeter protocol. The perception of dyspnea after each breath was determined using the Borg scale. Data concerning asthma control, medication in use, and use of rescue short-acting bronchodilators were recorded. RESULTS: Of the 65 patients included in the study, 53 completed the evaluation. Of those, 32 (60.5 percent) showed adequate perception of dyspnea after the methacholine challenge test, whereas 21 (39.5 percent) did not perceive any changes in the degree of dyspnea even after a 20 percent fall in FEV1. There were no significant differences between the two groups regarding baseline FEV1, percentage fall in FEV1, and the dose of methacholine causing a 20 percent fall in FEV1. The perception of dyspnea was not significantly associated with age (p = 0.247); gender (p = 0.329); use of maintenance medication (p = 0.152); asthma control (p = 0.562), bronchial hyperresponsiveness (p = 0.082); or severity of acute bronchoconstriction (p = 0.749). CONCLUSIONS: A significant proportion of asthma patients have a poor perception of dyspnea. The factors related to the inability of these patients to identify changes in pulmonary function have not yet been well defined. In order to reduce asthma-related morbidity and mortality, it is essential that this group of patients be identified and counseled.

Gender and perception of dyspnea: The role of the variation in the forced expiratory volume in one second / Género y percepción de disnea: el rol de la variación del volumen espiratorio forzado en un segundo

During bronchoconstriction women perceive more breathlessness than men. The aims of study were 1) to evaluate if quality of dyspnea in bronchoconstriction was different in women and men 2) to assess if gender difference in the perception of dyspnea could be related to the level of bronchoconstriction. 457 subjects (257 women) inhaled methacholine to a 20% decrease in FEV1, or 32 mg/ml. Dyspnea was evaluated using the modified Borg scale and a list of expressions of dyspnea. Borg scores were recorded immediately before the challenge test baseline and at the maximum FEV1 decrease. The prevalence of descriptors of dyspnea reported by women and men was similar. Dyspnea was related to the level of FEV1 (ΔFEV1: OR 1.05, 95%CI 1.01-1.09, p 0.0095), females (OR 2.90, 95%CI 1.33-6.33, p 0.0072), younger subjects (OR 0.93, 95%CI 0.89- 0.97, p 0.0013) and body mass index (BMI) (OR 1.11, 95%CI 1.01-1.23, p 0.023). As the FEV1 fell less than 20% from baseline, only the ΔFEV1 was significantly associated with dyspnea (ΔFEV1:OR 1.15, 95%CI 1.07- 1.24, p 0.0002). Instead, if the FEV1 fell higher ≥ 20%, the presence of dyspnea was related to the degree of bronchoconstriction (ΔFEV1: OR 1.04, 95%CI 1.01-1.09, p 0.0187), females (OR 3.02, 95%CI 1.36-6.72, p 0.0067), younger subjects (OR 0.92, 95%CI 0.88-0.96, p 0.0007) and BMI (OR 1.12, 95%CI 1.01-1.23, p 0.023). The quality of dyspnea during the bronchoconstriction was similar in women and men; women showed a higher perception of dyspnea than men only when the FEV1 fell more than 20% from baseline.

Durante la broncoconstricción las mujeres perciben más disnea que los hombres. Los objetivos del estudio fueron evaluar: 1) si la calidad de la disnea durante la broncoconstricción fue diferente en mujeres y hombres, 2) si la diferencia entre sexos en la percepción de disnea podría relacionarse al nivel de broncoconstricción. 457 sujetos (257 mujeres) inhalaron metacolina hasta un descenso del FEV1 ≥ 20% o 32 mg/ml. La disnea fue evaluada mediante escala de Borg y una lista de expresiones de disnea. El Borg fue registrado en forma basal y con el máximo descenso del FEV1. La frecuencia de descriptores de disnea informados por mujeres y hombres fue similar. La disnea estuvo relacionada al grado de broncoconstricción (ΔFEV1: OR 1.05, 95%CI 1.01-1.09, p 0.0095), sexo femenino (OR 2.90, 95%CI 1.33-6.33, p 0.0072), edad (OR 0.93, 95%CI 0.89-0.97, p0.0013) e índice de masa corporal (IMC) (OR 1.11, 95%CI 1.01-1.23, p 0.023). Cuando el FEV1 cayó menos del 20%, solo el ΔFEV1 se asoció con disnea (ΔFEV1: OR 1.15, 95%CI 1.07-1.24, p 0.0002). En tanto que si el FEV1 cayó ≥ del 20%, la disnea estuvo relacionada al grado de broncoconstricción (ΔFEV1: OR 1.04, 95%CI 1.01-1.09, p 0.0187), sexo femenino (OR 3.02, 95%CI 1.36-6.72, p 0.0067), edad (OR 0.92, 95%CI 0.88-0.96, p 0.0007) e IMC (OR 1.12, 95%CI 1.01-1.23, p 0.023). La calidad de la disnea durante la broncoconstricción fue similar en hombres y mujeres; las mujeres tuvieron mayor percepción de disnea que los hombres solo cuando el FEV1 descendió más del 20%.

Eficácia do formoterol na reversão imediata do broncoespasmo / Efficacy of inhaled formoterol in reversing bronchoconstriction

OBJETIVO: Avaliar efetividade e rapidez de ação do formoterol liberado através de inalador para pó seco na reversão de broncoespasmo induzido pela metacolina. MÉTODOS: Avaliaram-se prospectivamente 84 pacientes com queda do volume expiratório forçado no primeiro segundo 20 por cento após inalação de metacolina. Todos estavam sob investigação de sintomas respiratórios de etiologia não definida. Foram randomizados 41 pacientes para receber 200 mcg de fenoterol spray e 43 para receber 12 mcg de formoterol sob a forma de inalador de pó seco para reversão imediata do broncoespasmo. Avaliaram-se a queda no volume expiratório forçado no primeiro segundo inicial, dose provocadora de queda de 20 por cento do volume expiratório forçado no primeiro segundo inicial, e volume expiratório forçado no primeiro segundo após cinco e dez minutos da administração dos fármacos. RESULTADOS: Não houve diferença significativa entre os grupos em relação ao sexo, idade, peso, altura, dose provocadora de queda de 20 por cento do volume expiratório forçado no primeiro segundo, volume expiratório forçado no primeiro segundo inicial e pós-metacolina. A melhora do volume expiratório forçado no primeiro segundo após uso do broncodilatador foi de 34 por cento (cinco minutos) e 50,1 por cento (dez minutos) no primeiro grupo, e 46,5 por cento (cinco minutos) e 53,2 por cento (dez minutos) no segundo. CONCLUSÃO: O efeito broncodilatador do formoterol após cinco e dez minutos da indução de broncoespasmo pela metacolina foi similar ao do fenoterol. O formoterol, além de ser um broncodilatador de longa duração, tem também rápido início de ação, sugerindo que possa ser empregado como medicação de resgate nas crises de broncoespasmo.

OBJECTIVE: To evaluate the effectiveness and onset of action of formoterol delivered by dry-powder inhaler in reversing methacholine-induced bronchoconstriction. METHODS: Patients presenting a drop in forced expiratory volume in one second > 20 percent after methacholine inhalation were included. A total of 84 patients were evaluated. All of the participating patients presented respiratory symptoms of unknown origin, which were being investigated. The patients were randomized to receive 200 æg of spray fenoterol (n = 41) or 12 æg of dry-powder inhaler formoterol (n = 43), both administered in order to achieve immediate reversal of methacholine-induced bronchoconstriction. We evaluated the decrease in forced expiratory volume in one second (in relation to the baseline value) after methacholine challenge and the dose of methacholine required to provoke a drop of 20 percent in forced expiratory volume in one second, as well as the increase in forced expiratory volume in one second (in relation to the baseline value) at five and ten minutes after bronchodilator use. RESULTS: There were no significant differences related to gender, age, weight, height or dose of methacholine required to provoke a drop of 20 percent in forced expiratory volume in one second. Nor were there any significant differences in terms of baseline or post-methacholine forced expiratory volume in one second. In the fenoterol group, the mean postbronchodilator increase in forced expiratory volume in one second increase was 34 percent (at five minutes) and 50.1 percent (at ten minutes), compared with 46.5 percent (at five minutes) and 53.2 percent (at ten minutes) in the formoterol group. CONCLUSION: The bronchodilator effect of formoterol at five and ten minutes after methacholine-induced bronchoconstriction was similar to that of fenoterol. Despite being a long-acting bronchodilator, formoterol also has a rapid onset of action, which suggests that it could be employed ...

Antiallergic/antiasthmatic effect of novel antiallergic hexapeptide-95/220 in various experimental models.

The effects of newly synthesized antiallergic hexapeptide 95/220 was investigated on various allergic and asthmatic test models. This newly developed peptide was found to be more potent than clinically used drug disodium cromoglycate (DSCG). Hexapeptide 95/220 inhibited immediate hypersensitivity reactions such as passive cutaneous anaphylaxis (PCA) and mast cell degranulation in rats, antigen-induced bronchoconstriction in actively sensitized guinea pigs in dose dependent manner like DSCG. Antigen-induced contraction of guinea pig ileum was also markedly inhibited by this newly developed hexapeptide in the same fashion as ketotifen and DSCG did but at comparatively lower dose. Egg albumin-induced histamine release was also blocked by this hexapeptide from chopped lung tissues of sensitized guinea pigs. These results suggest that hexapeptide' 95/220 has potent inhibitory effect on immediate hypersensitivity reactions thereby inhibiting mediator release from mast cell. Moreover, this newly synthesized peptide is orally active and effective at lower doses as compared to standard drugs.

Effect of low temperature on tracheal smooth muscle contractile and relaxing responses evoked by electrical field stimulation

OBJECTIVE: The aim of this work was to evaluate the effect of low temperature (LT) on the contractile and relaxing responses of rat tracheas (RTs) after electrical field stimulation (EFS). METHODS: Voltage-dependent (10-60 V, 40 Hz) and frequency-dependent (0.1-60 Hz, 40 V) response curves were constructed at 37 and 18 degrees C after the activation of tracheal intramural nerves with a Grass S88 stimulator. The EFS that produced half of the maximum contractile response (ES50) at 37 or 18 degrees C was determined and considered as the dependent variable. The relaxation of pre-contracted RTs (EFS; 5 Hz, 40 V) to sodium nitroprusside (SNP; 1 x 10(-7) - 1 x 10(-3) M) isoproterenol (ISP; 1 x 10(-9) - 1 x 10(-5) M) and to 20 mM potassium chloride (KCl) after low-K+ inhibition of the Na+/K+ pump at 18 and 37 degrees C were determined. RESULTS: We found that the tracheal responses elicited by EFS at 37 and 18 degrees C were completely blocked with 1 microM atropine. LT slightly increases the voltage-dependent ES50, from 33.7 +/- 4.0 to 37.8 +/- 4.8 V, n = 5 but decreases the frequency-dependent ES50 from 19.3 +/- 4.3 to 1.0 +/- 0.28 Hz, n = 5, p < 0.05. Relaxing responses to SNP, ISP and KCl at 37 degrees C correspond to 43.5 +/- 6, 36.7 +/- 12 and 12.1 +/- 1.5 respectively. No significant tracheal relaxations were elicited at 18 degrees C. Our results indicate that in RTs, LT enhances tracheal sensitivity to EFS and decreases it in response to bronchorelaxants. The LT-dependent enhanced contractile response is observed only after a low frequency stimulation range (0.1-20 Hz), that is very close to the frequency of vagal stimuli required for inducing bronchoconstriction in vivo. Furthermore, LT abolishes the sensitivity of RTs to exogenously added bronchorelaxants (NO and ISP). In addition, LT appears to decrease the Na(+)-K+ pump activity; this effect has been associated with increased tracheal hyperreactivity in vitro. ACH appears to be the main endogenous neurotransmitter involved on neurally mediated contractile responses at 37 and 18 degrees C. CONCLUSION: Low temperature enhances the contractile response of rat tracheas in response to endogenous ACH release. The effect of LT is limited to frequencies below 20 Hz, which are within the physiological range required for bronchoconstriction. Furthermore, LT severely impairs the sensitivity of RTs to relaxant stimuli, either of endogenous of exogenous origin.

Efecto del Bromuro de ipratropio sobre la broncoconstriccion por histamina en sujetos con obstruccion cronica al flujo aereo / Effect of ipratropium bromide on histamine-induced bronchoconstriction in subjects with chronic airway obstruction

El bromuro de ipratropio (B I) es un agente anticolinérgico muy recomendado para el tratamiento de la obstrucción crónica al flujo aéreo (EPOC). No obstante, no hay definición respecto a la existencia de efectos preventivos (no broncodilatadores) del BI. Con el fin de evaluar la acción del BI (80 µg en aerosol) ante una prueba de histamina se estudiaron 9 sujetos (hombres) con EPOC moderada, mediante un diseño doble ciego, aleatorio, controlado y cruzado entre placebo y BI. Tenían una edad promedio (ñ error standard de media) = 57,9 ñ 2,4 años con antecedentes de tabaquismo de 54,6 ñ 5,1 paquete-años y un FEV1 basal = 1,36 ñ 0,08 litros (47,2 ñ 3,8 percent del teórico).La hiperreactividad bronquial a la histamina en el día control fue logPC20 =-0,54 ñ 0,24 mg/ml (media geométrica: 0,27 mg/ml). El BI produjo un aumento significativo en el FEV1 basal; aunque no hubo correlación entre la obstrucción basal (FEV1, FEV1/FVC percent) y la broncodilatación con la hiperreactividad (logPC20). El BI redujo la broncoconstricción por histamina (logPC20 BI = -0,15 ñ 0,17 mg/ml; media geométrica [MG] = 0,70 mg/ml) en comparación con placebo (logPC20 post placebo = -0,76 ñ 0,22 mg/ml [MG = 0,17 mg/ml]; P = 0,018) y la dosis doble fue para BI = 2,02 ñ 0,68 vs placebo = -0,62 ñ 0,79; p: 0,024. Tanto el fenoterol como el BI revirtieron totalmente la caída del FEV1 al final de la prueba de histamina. Se concluye que el BI mostró un efecto protector ante la histamina en estos sujetos con diagnóstico de EPOC moderada

Protective effects of different doses of inhaled fenoterol on methacholine-induced bronchoconstriction in asthmatic children

Objective: To evaluate the protective effect of different doses of inhaled fenoterol (F) on bronchoconstriction induced by methacholine (M). Design: randomized double-blind study. Setting: Referrence center. Participants: 9 children (aged from 7 to 15 years old), with mild or moderate asthma and allergic to D. pteronyssinus. Intervention: On the first day, the M concentration necessary to induce a 20 per cent fall in the forced expiratory volume in the first second (FEV(1); PC(20)FEV(1)) was determined using closed circuit inhalation (De Vilbiss 646). On subsequent days, the children inhaled a dose of F (25 or 50 or 100 or 220 mug) through the same circuit and, after 15 minutes the FEV(1), was measured, becoming the basal value. Bronchoprovocation was then initiated using the concentration prior to the PC(20)FEV(1) of the first day and continuing until there was a 20 per cent fall in the FEV(1). This concentration was the "new" PC(20)FEV(1). Results. F in a dose of 25 mug protected 2 of the 9 children, in a dose of 50 mg protected 4 of the 9 and in doses of 100 and 200 mug protected all children. We did not observe any relationship between the magnitude of the bronchodilation and bronchoprotection induced by the inhalation of F. Conclusions: Our results suggest that a dose of 100 mug of F is capable of inducing bronchoprotection in children with mild/moderate asthma.

Atrial natriuretic peptide prevents bronchoconstriction in vitro.

Under in vitro conditions atrial natriuretic peptide (ANP) caused specific relation of bronchoconstriction induced by tosyl arginine methyl ester (TAME) on rat trachea. This supports the hypothesis that ANP is a relaxant of airway as well as vascular smooth muscle and since lung tissue contains ANP and ANP receptors, it is hypothesized that the lungs may be a target organ for ANP. It is concluded that ANP had definite bronchodilating properties on rat trachea mounted in vitro and could be a possible antagonist of TAME.

Effect of calcium channel antagonists on cholinergic bronchial responsiveness in asthma.

Bronchial responsiveness to methacholine was studied in 23 stable asthmatics before and after nifedipine and diltiazem. There was no significant bronchodilatory effect of either calcium channel antagonists. The mean provocative dose of methacholine required to produce a 20% fall in FEV1 (PC20 = 0.157 +/- 0.74 mg) was not altered by nifedipine (PC20 = 0.159 +/- 0.61). However, diltiazem offered significant protection. The mean ratio of PC20 after diltiazem over baseline was 3.27 +/- 3.55. The results suggest that although both calcium channel antagonists have no influence on normal basal bronchomotor tone, diltiazem does significantly protect against cholinergic stimulation.

Effect of honey on tracheobronchial tree of adult male guinea pigs

The effect of honey on the bronchoconstriction induced by histamine [0.5%] and acetylcholine [4%] aerosols in normal conscious guinea pigs, as well as its antianaphylactic effect on sensitized guinea pigs exposed to the antigen [5% ovalbumin aerosol] have been evaluated. Pretreatment with honey [3 g/kg] prolonged the preconvulsive time of normal conscious guinea pigs exposed to histamine, acetylcholine aerosols, or sensitized guinea pigs exposed to the antigen [5% ovalbumin] aerosol. The effect in the latter one is better than the first two types. This denoted that honey can be used for treatment of bronchial asthma due to its antagonistic effect to hypersensitivity reactions

A comparison of different intervals of administration of inhaled terbutaline in children with acute asthma.

Thirty asthmatic children, 5 to 14 years of age, 20 boys and 10 girls, were studied while having acute asthmatic attacks. Each group of 10 children received either a single dose of 6 puffs (1500 micrograms) or 3 doses of 2 puffs (500 micrograms) at 5-minute or 15-minute intervals of terbutaline pressurized aerosol inhaler through a 750-ml volumetric spacer. The onset of bronchodilatation was observed within 2 minutes in all. The 3 doses at 15-minute intervals gave the greatest bronchodilatation throughout the 6-hour study period in comparing with the other two regimens. Slightly insignificant increases in systolic blood pressure and heart rate were observed in all groups and there were no statistically significant differences among them. No serious side effects were observed.

Prediction of airway responsiveness to allergen from skin sensitivity to allergen, airway responsiveness to histamine and serum IgE levels.

Immediate allergic reaction of the skin, non allergic airway responsiveness of the bronchi, and serum IgE levels were estimated in 25 atopic non asthmatic subjects and 15 controls. A good correlation was observed between these three parameters i.e. patients with positive skin response to allergen had increased airway responsiveness and significantly increased levels of serum IgE. However, the serum levels of IgE provided a significantly better indication of the likely presence of bronchial allergic reactivity than did the skin reactivity. The results indicate that knowledge of the airway responsiveness to histamine, skin sensitivity to allergen and serum IgE levels can predict the presence of airways responsiveness to an allergen. In all atopic non asthmatic individuals with a significant correlation between these parameters, the relevant allergen could stand identified as having the potential to provoke attacks of clinical asthma.

Significant changes of bronchial responsiveness to methacholine after early asthmatic reaction to toluene diisocyanate (TDI) in a TDI-sensitive asthmatic worker

Current asthma is often diagnostically excluded by the presence of normal bronchial responsiveness. We report on a TDI-induced occupational asthma patient with normal bronchial responsiveness. He had suffered from shortness of breath during and after TDI exposure for several months. His initial methacholine bronchial challenge test showed a negative response. The bronchoprovacation test with TDI showed an isolated immediate bronchoconstriction. The following methacholine bronchial challenge tests revealed that the bronchial hyperresponsiveness developed seven hours after the TDI challenge (methacholine PC20:5.1 mg/ml), progressed up until 24 hours, and returned to normal on the seventh day. This case provides evidence that the response of the airway to TDI may not always be accompanied by bronchial hyperresponsiveness to methacholine. Screening programs utilizing methacholine challenges may not always identify TDI-sensitized asthmatic workers.

Reactive dye induced occupational asthma without nonspecific bronchial hyperreactivity

Current asthma is often excluded by the presence of normal bronchial hyperresponsiveness. We report two asthmatic patients with normal bronchial hyperresponsiveness and one asthmatic patient with mild bronchial hyperresponsiveness (methacholine PC20; 24 mg/ml) which was presumed to be caused by sensitization and exposure to Black GR, the most frequent sensitizer among reactive dyes. They all complained of lower respiratory symptoms after work as well as at the workstation. The bronchoprovocation test with Black GR revealed isolated immediate bronchoconstrictions in all 3 patients and all had high specific IgE antibodies to Black GR-human serum albumin conjugate. After one worker continued at work for 3 days, he experienced a marked drop of methacholine PC20, and it returned to the pre-exposure level during 1 week. The other patient whose initial methacholine challenge was negative developed bronchial hyperresponsiveness on the first day after the dye bronchoprovocation, and returned to normal bronchial hyperresponsiveness on the third day. These findings suggested that patients with occupational asthma caused by reactive dye may not always have bronchial hyperresponsiveness to methacholine, and the screening program utilizing methacholine challenges may not always identify these patients.