The Effect of Dual Bioactive Compounds Artemisinin and Metformin Co-loaded in PLGA-PEG Nano-particles on Breast Cancer Cell lines: Potential Apoptotic and Anti-proliferative Action.

The most prevalent malignancy among women is breast cancer. Phytochemicals and their derivatives are rapidly being recognized as possible cancer complementary therapies because they can modify signaling pathways that lead to cell cycle control or directly alter cell cycle regulatory molecules. The phytochemicals' poor bioavailability and short half-life make them unsuitable as anticancer drugs. Applying PLGA-PEG NPs improves their solubility and tolerance while also reducing drug adverse effects. According to the findings, combining anti-tumor phytochemicals can be more effective in regulating several signaling pathways linked to tumor cell development. The point of the study was to compare the anti-proliferative impacts of combined artemisinin and metformin on cell cycle arrest and expression of cyclin D1 and apoptotic genes (bcl-2, Bax, survivin, caspase-7, and caspase-3), and also hTERT genes in breast cancer cells. T-47D breast cancer cells were treated with different concentrations of metformin (MET) and artemisinin (ART) co-loaded in PLGA-PEG NPs and free form. The MTT test was applied to assess drug cytotoxicity in T47D cells. The cell cycle distribution was investigated using flow cytometry and the expression levels of cyclin D1, hTERT, Bax, bcl-2, caspase-3, and caspase-7, and survivin genes were then determined using real-time PCR. The findings of the MTT test and flow cytometry revealed that each state was cytotoxic to T47D cells in a time and dose-dependent pattern. Compared to various state of drugs (free and nano state, pure and combination state) Met-Art-PLGA/PEG NPs demonstrated the strongest anti-proliferative impact and considerably inhibited the development of T-47D cells; also, treatment with nano-formulated forms of Met-Art combination resulted in substantial downregulation of hTERT, Bcl-2, cyclin D1, survivin, and upregulation of caspase-3, caspase-7, and Bax, in the cells, as compared to the free forms, as indicated by real-time PCR findings. The findings suggested that combining an ART/MET-loaded PLGA-PEG NP-based therapy for breast cancer could significantly improve treatment effectiveness.

Bronchial challenge, assessed with forced expiratory manoeuvres and airway impedance.

OBJECTIVE: The Methacholine concentration at which a 20% decrease of the forced expiratory volume in 1s (PC20_FEV1) or a 40% increase in airway resistance (PC40_Rrs6) occur are accepted indicators for airway hyperresponsiveness. We hypothesised that the level of detection of bronchial hyperresponsiveness will differ between the two methods. METHODS: The response to Methacholine was assessed by forced oscillation technique (FOT) and spirometry in 20 stable hyperresponsive asthmatics. The effects of repeated lung function measurements on respiratory muscle fatigue were measured from maximal inspiratory mouth pressure (MIP). After each dose, patients scored their perception of dyspnoea on a BORG scale. Differences in patient's burden were measured by comparing the BORG-score at PC40_Rrs6 (BORG-PC40_Rrs6) and at PC20_FEV1 (BORG-PC20_FEV1). Reproducibility was also evaluated. RESULTS: The PC20_FEV1-values were 2.2 (0.4) doubling dose higher as compared to the PC40_Rrs6 (P<0.001). The mean BORG-score at PC40_Rrs6 was 1.7 points lower as compared to the BORG-score at PC20_FEV1 (P<0.001). The difference (mean(sd)) between the PC20_FEV1 of measurement 1 and 2 was -0.1 (1.4) doubling dose, and -0.3 (2.7) doubling dose for PC40_Rrs6. The MIP after Methacholine provocation was 1.0(0.2) kPa lower as compared to the MIP before the challenge test (P<0.001), suggesting respiratory muscle fatigue. CONCLUSION: Measuring PC40_Rrs6 shortens the challenge test and lowers the concentrations of bronchoconstrictor agents as compared to measurements of PC20_FEV1. The FOT-method was less strenuous for patients. In spite of the fact that the reproducibility is two-fold worse than measuring PC20_FEV1, it still remains quite acceptable at a mean of 0.3 doubling dose. The respiratory muscle strength was deteriorated after the challenge test.

Long-term follow-up of toluene diisocyanate-induced asthma.

Eighty-seven cases of occupational asthma induced by toluene diisocyanate (TDI) were diagnosed by an inhalation challenge with TDI and methacholine. After an average follow-up interval of 11 yrs, all subjects were re-examined. Of the 87 subjects examined, 13 (15%) had remained in the same job, 44 (50.5%) had been removed from exposure for <10 yrs and 30 (34.5%) had been removed for >10 yrs. The proportion of subjects who experienced symptoms of asthma and those who were hyperresponsive to methacholine was significantly lower. Of the patients, 59% used short-acting bronchodilators, 8% long-acting bronchodilators and 18% were on regular inhaled glucocorticoids. Thus, multiple regression analysis showed a positive correlation between forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) at follow-up and FVC and FEV1 at diagnosis, and a negative correlation with smoking and with therapy with bronchodilators. Stepwise logistic regression showed that the follow-up provocative dose causing a 20% fall in the FEV1 (PD20) could be predicted from baseline PD20. These results indicate that respiratory symptoms and airway hyperresponsiveness to methacholine persist in subjects removed from exposure to TDI for >10 yrs. A more favourable prognosis was associated with a better lung function and a lower degree of airway hyperresponsiveness to methacholine at diagnosis.

Oropharyngeal angioedema induced by inhaled histamine.

Inhaled histamine used to measure airway responsiveness produces some side effects more frequently than does methacholine. It is possible that the inhaled histamine induces the side effects in asthmatics with increased end organ responsiveness to histamine. A 56-yr-old woman with chronic idiopathic angioedema presented with asthma-like symptoms. Methacholine challenge test was performed, with a negative result. Five days later, histamine inhalation test was done. FEV1 fell by 37% after inhalation of histamine concentration of 8 mg/mL. Immediately thereafter, severe angioedema on face, lips, and oropharyngeal area, foreign body sensation at throat, and hoarseness occurred. To assess end organ responsiveness to histamine, skin prick tests with doubling concentrations of histamine (0.03-16 mg/mL) were carried out on the forearm of the patient and six age- and sex-matched asthmatic controls. The wheal areas were measured. The patient showed greater skin responses than the controls. Regression analysis showed that the intercept and slope were greater than cut-off levels determined from six controls. The patient showed an increased skin wheal response to histamine, indicating the enhanced end organ responsiveness to histamine, which is likely to contribute to the development of the oropharyngeal angioedema by inhaled histamine.

[The effects of ozone and toxic air particles on airway function in mice]. / Vplyv ozonu ta toksychnykh chastok povitria na dykhal'ni shliakhy myshei.

We tested the hypothesis that exposures to particulate matter and ozone can produce asthma-like symptoms. Balb/c mice received a single intratracheal instillation of particulate matter and TiO2 or they were exposed to low concentration of ozone. We have established that exposure to particulate matter produces increased responsiveness to methacholine in mice. Exposure to ozone and TiO2 did not produce changes in respiratory mechanics. These data are spreading our understanding about mechanisms of environmental influence on airways.

TNF-alpha dysregulation in asthma: relationship to ongoing corticosteroidtherapy.

BACKGROUND: Tumour necrosis factor-alpha (TNF-alpha) is a major proinflammatory cytokine that is thought to be important in the pathogenesis of asthma. However, alterations in systemic regulation of this cytokine in asthma have not been examined in the context of corticosteroid therapy. OBJECTIVES: To examine the ability of peripheral blood mononuclear cells (PBMC) from three different groups of patients with asthma requiring varying amounts of inhaled corticosteroids (ICS) for clinical control, and to examine cells from age- and sex-matched nonasthmatic patients to produce TNF-alpha. DESIGN: All patients with asthma had a positive methacholine challenge test. 'High dose' ICS patients with asthma required ICS greater than or equal to 800 microg/day. 'Medium dose' patients with asthma were on less than or equal to 500 microg/day of ICS, whereas 'no ICS' patients with asthma had received no ICS for at least three months. Each patient with asthma was examined in parallel with an age- and sex-matched, nonasthmatic, nonatopic control subject. Cells were cultured (with or without the addition of potential stimulators phytohemagglutinin, lipopolysaccharide, formyl-methionine-leucine-phenylalanine or antihuman CD3), and TNF-alpha production was assessed by ELISA. MAIN RESULTS: PBMC from both high dose ICS (n=8) and no ICS (n=11) patients with asthma produced more than twice the amount of TNF-alpha than cells from matched nonasthmatic control patients (P<0.01) when cultured alone or in the presence of each stimulus (P<0.05). In contrast, there was no significant difference in TNF-alpha production between medium dose ICS patients with asthma and control patients. A group of asymptomatic atopic patients (n=6) did not have an increased level of TNF-alpha production. CONCLUSIONS: Increases in TNF-a production within the PBMC compartment can be observed in both patients with asthma receiving high dose ICS and in a group of patients with mild asthma receiving no ICS therapy, but not in patients with asthma receiving a medium dose of ICS or atopic patients.

Perception of bronchoconstriction and bronchial hyper-responsiveness in asthma.

The inter-relationship between the perception of bronchoconstriction, bronchial hyper-responsiveness and temporal adaptation in asthma is still a matter of debate. In a total of 52 stable asthmatic patients, 32 without airway obstruction ¿forced expiratory volume in 1 s (FEV(1))/vital capacity (VC) 84.1% (S.D. 7.9%), and 20 with airway obstruction [FEV(1)/VC 60% (4%)], we assessed the perception of bronchoconstriction during methacholine inhalation by using: (i) the slope and intercept of the Borg and VAS (Visual Analog Scale) scores against the decrease in FEV(1), expressed as a percentage of the predicted value; and (ii) the Borg and VAS scores at a 20% decrease in FEV(1) from the lowest post-saline level (PB(20)). Bronchial hyper-responsiveness was assessed as the provocative concentration of methacholine causing a 20% fall in FEV(1) (PC(20)FEV(1)). The reduction in FEV(1) was significantly related to the Borg and VAS scores, with values for the group mean slope and intercept of this relationship of 0.13 (S.D. 0.08) and -1.1 (3.02) for Borg, and 1.5 (1.19) and -12.01 (35) for VAS. PB(20) was 3 (1.75) with Borg scores and 34.6 (20.5) with VAS scores. Compared with the subgroup without airway obstruction, the obstructed subgroup exhibited similar slopes, but lower Borg and VAS intercepts. For similar decreases in FEV(1) (5-20% decreases from the lowest post-saline values), the Borg and VAS scores were lower in the non-obstructed than in the obstructed subgroup. PC(20)FEV(1) was significantly related to both Borg PB(20) and VAS PB(20) when considering all patients. When assessing the subgroups, PC(20)FEV(1) was related to Borg PB(20) and VAS PB(20) in the non-obstructed subjects, but not in the obstructed subjects. In neither subgroup was the log of the cumulative dose related to the Borg and VAS scores at the end of the test. We conclude that, unlike in previous studies, the ability to perceive acute bronchoconstriction may be reduced as background airflow obstruction increases in asthma. Bronchial hyper-responsiveness did not play a major role in perceived breathlessness in patients without airway obstruction, and even less of a role in patients with obstruction. The cumulative dose of agonist did not appear to influence the perception of bronchoconstriction.

Induced sputum: comparison of postinfectious cough with allergic asthma in children.

BACKGROUND: Cough persisting after a respiratory infection is common in children and is often managed as asthma. However, little is known about the pathophysiologic mechanisms of such cough and how it compares with asthma. OBJECTIVE: We used the technique of induced sputum to examine the inflammatory index values associated with persistent cough or allergic asthma in children. We hypothesized that the sputum from children with persistent postinfectious cough would differ from that of children with allergic asthma in that the former would lack eosinophils compared with the latter. STUDY DESIGN: Sputum production was induced with hypertonic saline solution in 34 children: 12 with cough persisting for 1 month or more after an apparent respiratory tract infection, not treated with corticosteroid; 11 with untreated atopic asthma, not using inhaled corticosteroid; and 11 with treated atopic asthma using inhaled corticosteroid. RESULTS: The percentage of eosinophils in the sputum of children with cough was significantly lower than in the sputum of children with untreated allergic asthma (median 0.5% vs 14.5%, P <.0001). Similarly, the percentage of eosinophils in the sputum of children with asthma treated with inhaled steroids was significantly lower compared with untreated asthmatic children (1.5% vs 14.5%, P <.0001). The peripheral blood eosinophils, serum eosinophil cationic protein, and nasal percent eosinophils of the patients with cough were also significantly lower than those from patients with untreated asthma. Methacholine challenge in 6 of the 11 cough patients tested showed mild-to-moderate hyperresponsiveness, whereas the other 5 had a negative methacholine challenge. CONCLUSIONS: Children with persistent postinfectious cough do not have airway eosinophilia typical of untreated asthma. Despite the absence of eosinophilic inflammation, some of the patients with chronic cough had reactive airways. These results suggest that postinfectious cough in children has different pathophysiologic features than allergic asthma and probably represents a different disease.

The relationship between airways inflammation and asthma severity.

In order to investigate the relationship between airways inflammation and disease severity, and improve the understanding of persistent asthma, 74 asthmatics, with disease severity ranging from intermittent, to mild to moderate and severe persistent (classified according to the Global Initiative for Asthma [GINA] guidelines), and 22 nonatopic control subjects were studied using the method of induced sputum. Sputum was analyzed for total and differential cell counts concentrations of albumin, and levels of eosinophil cationic protein (ECP), myeloperoxidase (MPO), and tryptase, inflammatory mediators reflecting eosinophil, neutrophil, and mast cell activation. Asthma severity (assessed by FEV(1), peak expiratory flow [PEF] variability, and daily symptom scores) and methacholine airways responsiveness were related to sputum eosinophilia and ECP. In addition, sputum neutrophilia and MPO levels correlated, albeit weakly, with PEF variability and symptom scores, respectively. Tryptase concentrations were raised in mild to moderate asthmatics. Albumin concentrations were significantly raised across the spectrum of asthma severity and correlated with those of tryptase and ECP. Despite treatment with either high doses of inhaled corticosteroids or oral corticosteroids, prominent eosinophilic inflammation with raised ECP was noted. This study points to persistent, disease severity-related airways inflammation in asthma, involving eosinophils, mast cells, and neutrophils, which is evident despite treatment with corticosteroids.

Hiperreactividad en 30 niños sin asma con dermatitis atópica / Bronchial hyperreactivity in children with atopic dermatitis

Introducción. La importancia de la dermatitis atópica (DA) no sólo radica en su alta morbilidad, con topografía y morfología dérmica características, sino que además existen manifestaciones extracutáneas, de las cuales la hiperreactividad bronquial (HRB) puede estar presente expresándose posteriomente como asma bronquial, por este motivo el objetivo del trabajo fue determinar la presencia de HRB en 30 niños con DA sin diagnóstico de asma o afección pulmonar previa. Material y métodos. Se realizó un estudio prospectivo, transversal, en 30 niños de 6 a 16 años de edad que acudieron al Hospital Infantil de México Federico Gómez con diagnóstico de DA. Para determinar la presencia de HRB se realizaron pruebas de función pulmonar (espirometría basal y posterior al reto con diferentes concentraciones de metacolina). El análisis estadístico se llevó a cabo por la prueba t de Student pareada con corrección de Kurtosis. Resultados. La edad media fue de 11 años, con una relación femenino/masculino de 1.5: 1. De los 30 pacientes, 21 tuvieron reto positivo, demostrado por el descenso del VEF1 con respecto a la basal de 20 por ciento acompañándose de tos, opresión torácica y sibilancias. Al analizar los valores del VEF1 se encontró significancia estadística (P=0.0125) de los basales comparados con cada reto. De esta manera se observa que 70 por ciento tuvo HRB, concordando con lo reportado por otros autores, en los cuales más de la mitad de los pecientes con DA presentan HRB. Conclusión. Es necesario vigilar estrechamente a los pacientes con DA ya que como se demostró en este estudio, existe la posibilidad de que en algún momento de la vida pudieran presentar asma bronquial y aunque no se pueda evitar en su totalidad sí se podrían tomar las medidas necesarias para disminuir esta posibilidad basados en la pevención

Occupational asthma and food allergy due to carmine.

Carmine (E120), a natural red dye extracted from the dried females of the insect Dactylopius coccus var. Costa (cochineal), has been reported to cause hypersensitivity reactions. We report a case of occupational asthma and food allergy due to carmine in a worker not engaged in dye manufacturing. A 35-year-old nonatopic man, who had worked for 4 years in a spice warehouse, reported asthma and rhinoconjunctivitis for 5 months, related to carmine handling in his work. Two weeks before the visit, he reported one similar episode after the ingestion of a red-colored sweet containing carmine. Peak flow showed drops higher than 25% related to carmine exposure. Prick tests with the cochineal insect and carmine were positive, but negative to common aeroallergens, several mites, foods, and spices. The methacholine test was positive. Specific bronchial challenge test with a cochineal extract was positive with a dual pattern (20% and 24% fall in FEV1). Double-blind oral challenge with E120 was positive. The patient's sera contained specific IgE for various high-molecular-weight proteins from the cochineal extract, as shown by immunoblotting. Carmine proteins can induce IgE-mediated food allergy and occupational asthma in workers using products where its presence could be easily overlooked, as well as in dye manufacture workers.

Determinants of bronchial responsiveness in the European Community Respiratory Health Survey in Italy: evidence of an independent role of atopy, total serum IgE levels, and asthma symptoms.

The aim of the analysis was to test whether total serum IgE levels, specific serum IgE levels, and asthma symptoms are independent predictors of bronchial hyperresponsiveness (BHR), after controlling for known risk factors or potential confounders. The study was carried out on a sample of 875 young adults, 20-44 years old, who took part in the European Community Respiratory Health Survey in Italy. The subjects underwent a dose-response methacholine challenge test. We also measured airway caliber as the baseline FEV1 in absolute terms and as percentage of forced vital capacity (FVC); skin wheal response to 11 common environmental allergens; and total and specific serum IgE levels to mites, molds, pets, and respiratory symptoms by means of a standardized questionnaire. Atopy (positive skin prick test and/or positive specific IgE assay), total IgE, asthma symptoms, airway caliber, and age appeared to be independent predictors of BHR. When all the other risk factors were taken into account, atopy and total IgE were associated with a threefold increase in BHR risk and thus emerged as the main determinants of BHR. The importance of symptom status as a determinant of BHR decreased remarkably after controlling for atopy and IgE: the odds ratio of current asthmatics to asymptomatic subjects decreased from 15.3 to 8.8. When controlling for symptoms and atopy, a family history of allergic diseases and early respiratory infections was not found to be associated with BHR. Both FEV1 and FEV1/FVC were strongly and inversely associated with BHR. When airway caliber was taken into account, older age was associated with decreased responsiveness, and the level of responsiveness did not differ significantly between males and females and between smokers and nonsmokers. The results from this analysis indicate that at any given age, irrespective of sex and smoking habits, total serum IgE, specific IgE, airway caliber, and asthma symptoms are the main independent factors influencing the occurrence of BHR in a young adult sample.

Estimation of thickness of airway surface liquid in ferret trachea in vitro.

The tracheae of ferrets and rabbits were mounted in vitro in organ baths. While the tracheae were liquid filled, the permeability coefficient ( P) was determined, and then while the tracheae were air filled, the percent clearance for 99mTc-labeled diethylenetriaminepentaacetic acid (DTPA) was determined. The thickness of airway surface liquid (ASL) was estimated by three methods. 1) The initial concentration of 99mTc-DTPA and the total amount of 99mTc-DTPA (the sum of that entering the outside medium, that draining from the trachea, and that washed out at the end of 40 min) gave the initial volume of ASL and thus its thickness. Mean values were 45.7 micron for the ferret and 41.9 micron for the rabbit. 2) Estimates of ASL thickness at the end of the 40-min period, based on the final 99mTc-DTPA concentration and the amount in the washout, were 42.9 micron for ferret and 45.4 micron for rabbit. 3) The ratio of P to percent clearance gave mean ASL thickness values of 49.2 micron for the ferret and 40.3 micron for the rabbit. Thus three separate methods for determining ASL thickness give very similar results, with means in the range 40-49 micron. Administration of methacholine or atropine to ferret tracheae did not significantly change ASL thickness.

Econazole, miconazole and SK & F 96365 inhibit depolarization-induced and receptor-operated contraction of guinea-pig isolated trachea in vitro.

Econazole, miconazole, SK & F 96365 and nifedipine inhibited Ca2+- and depolarization-induced and receptor-operated contraction of guinea-pig isolated trachea. Econazole, miconazole and SK & F 96365 inhibited histamine- and methacholine-induced tracheal contraction more than nifedipine. Nifedipine was more potent in inhibiting KCl-induced contraction. Nifedipine, salbutamol and theophylline, but not econazole, miconazole or SK & F 96365, relaxed KCl, histamine-, and methacholine-precontracted trachea. It appears that in the guinea-pig tracheal smooth muscle, econazole, miconazole and SK & F 96365 behave differently from nifedipine, theophylline and salbutamol. Econazole, miconazole and SK & F 96365 are thus introduced as novel antagonists of receptor-operated airway smooth muscle contraction.

Interpolación y extrapolación computarizadas de la PC20 de metacolina usando diferentes modelos matemáticos / Computarized interpolation and extrapolation of the methacholine PC20 using differents mathematical models

Las curvas de dosis-respuesta (CDR) de 33 niños asmáticos en los cuales se había alcanzado PC20 (concentración de metacolina inhalada capaz de disminuir el volumen espiratorio forzado en 1 segundo (VEF1) en 20 porciento respecto del valor control), fueron empleadas para el análisis. El cálculo de la PC20 mediante interpolación o extrapolación se hizo con un programa computacional diseñado para tal fin. Para la interpolación se emplearon los siguientes modelos: cuadrático (todos los puntos), lineal (últimos 2 puntos), logarítmico de los últimos 2 puntos y también el método manual en el cual la PC20 se calculó por interpolación gráfica de los últimos 2 puntos (gráfico en papel semi-log). Para la extrapolación se consideraron los puntos de la CDR localizados sobre la linea del 20 porciento de caida del VEF, y los modelos empleados fueron: cuadrático (todos los puntos), lineal (últimos 2 puntos), y lineal (primero y último punto). El análisis estadístico se realizó mediante ANOVA

Characteristics of bronchial asthma with incomplete reversibility of airflow obstruction.

BACKGROUND: Incomplete reversibility of airflow obstruction (IRAO) can be observed in some asthmatic patients without significant smoking history nor evidence of other respiratory condition. The characteristics of this group remain however to be defined. METHODS: We compared 18 asthmatic patients with persistent airflow obstruction, defined as an FEV1 < or = 75% predicted despite optimal corticosteroid treatment, to others with complete reversibility of airflow obstruction, paired for age and gender (CRAO, FEV1 > 80% of predicted). RESULTS: Mean duration of asthma was 31.6 years for IRAO patients and 17.7 for the CRAO group and mean baseline FEV1 was 48.6 +/- 2.6% and 89.3 +/- 3.4%, respectively. Patients with IRAO had more severe airflow obstruction and hyperinflation than those with CRAO, while lung compliance and CO diffusion were similar. Overall healthcare use was similar in the two groups, but those with IRAO had a greater global asthma-related discomfort, increased diurnal variation of airflow obstruction and used higher doses of inhaled corticosteroids than those with CRAO. Patients with IRAO had slightly increased airway wall thickness on high resolution chest tomography compared with CRAO. Baseline FEV1 however, was not correlated with the measured airway wall thickness. CONCLUSION: We found that asthmatic patients with IRAO have a more severe asthma and asthma of longer duration than asthmatic subjects with CRAO. Our data suggest that in asthma, IRAO may result from long-standing airway inflammation and associated structural changes, although this remains to be further documented.

Effect of inhaled furosemide and cromolyn on bronchoconstriction induced by ultrasonically nebulized distilled water in asthmatic subjects.

BACKGROUND: Inhaled furosemide has been shown recently to produce a protective effect against bronchoconstriction induced by several indirect stimuli, including ultrasonically nebulized distilled water (UNDW). Since there is a close parallel between its experimental effects and those reported for cromolyn,/it has been suggested that they may share some common mechanisms of action. Their protective effect, however, has never been compared directly. In this study, therefore, we have investigated the ability of equal doses (30 mg) of inhaled furosemide and cromolyn to modulate bronchoconstriction induced by UNDW in a group of ten asthmatic patients. METHODS: Subjects with documented bronchial response to UNDW were enrolled in a randomized, double-blind, placebo-controlled study. Treatments were administered five minutes prior to increasing outputs of UNDW and the response was expressed as the provocative output causing a 20% fall in FEV1 (PO20, in mL/min) and as the output-response slope. RESULTS: Geometric mean PO20 increased from 1.53 to 4.05 mL/min (P < .0004) after furosemide. After inhaling the highest output of UNDW (5.2 mL/min), PO20 was not measurable in six of ten patients when pretreated with furosemide and in all patients when pretreated with cromolyn. This difference was statistically significant (P < .05). Geometric mean values of output-response slope significantly decreased from 13.6 to 2.97 after furosemide (P < .0001) and from 13.6 to 1.43 (P < .0002) after cromolyn. CONCLUSIONS: These results suggest that cromolyn has a slightly greater anti-reactive activity in UNDW-induced bronchoconstriction compared to furosemide.

Muscarinic and nicotinic receptors raise intracellular Ca2+ levels in rat carotid body type I cells.

1. The effects of cholinergic agonists upon intracellular free Ca2+ levels ([Ca2+]i) have been studied in enzymically isolated rat carotid body single type I cells, using indo-1. 2. Acetylcholine (ACh) dose-dependently increased [Ca2+]i in 55% of cells studied (EC50 = 13 microM). These [Ca2+]i rises were partially inhibited by atropine or mecamylamine. 3. Specific nicotinic and muscarinic agonists also elevated [Ca2+]i in a dose-dependent manner (nicotine, EC50 = 15 microM; methacholine, EC50 = 20 microM). 4. While the majority of the ACh-sensitive cells responded to both classes of cholinergic agonist, 29% responded exclusively to nicotinic stimulation and 9% responded exclusively to muscarinic stimulation. 5. In the presence of nicotinic agonists, Ca2+i responses were transient. In the presence of muscarinic agonists, Ca2+i responses consisted of an initial rise, which then declined to a lower plateau level. 6. Nicotinic responses were rapidly abolished in Ca(2+)-free medium, suggesting that they are dependent on Ca2+ influx. 7. The plateau component of the muscarinic-activated response was also abolished in Ca(2+)-free conditions. The rapid initial [Ca2+]i rise, however, could still be evoked after several minutes in Ca(2+)-free medium. Muscarine also increased Mn2+ quenching of intracellular fura-2 fluorescence. These data suggest that the full muscarinic response depends on both Ca2+ release from intracellular stores and Ca2+o influx. 8. The results indicate that, in rat carotid body type I cells, both nicotinic and muscarinic acetylcholine receptors increase [Ca2+]i, but achieve this via different mechanisms. ACh may therefore play a role in carotid body function by modulating Ca2+i in the chemosensory type I cells.

Comparison between the effect of ipratropium bromide as a pressurized aerosol and as an aqueous pump spray on methacholine-induced rhinorrhoea.

Topical application of the anti-cholinergic drug ipratropium bromide is used for the treatment of rhinorrhoea. As the commercially-available pressurized aerosols are now largely being replaced by aqueous pump sprays, not containing CFC gases, we have compared these two types of sprays in a time-effect study of 20 normal persons, using the secretory response to nasal methacholine challenge as the effect parameter. Pre-treatment has been given as a single dose of 80 mg of ipratropium bromide, and 24 mg methacholine was used for challenge. The pressurized aerosol reduces rhinorrhoea with 60% (p < 0.05) and the effect lasts for at least 8 h. The corresponding value for the aqueous pump spray is 40% (p < 0.05) and the effect lasts for less than 4 h. The differences between the two sprays is significant 30 min, 1, 2 and 4 h after medication (p < 0.05). This finding is unexpected and we cannot offer a satisfactory explanation. The result indicates that changes in dosing and dose-frequency of ipratropium bromide may be necessary when patients are transferred from a pressurized spray to an aqueous pump spray.