Comparison of two twice-daily doses of budesonide/formoterol maintenance and reliever therapy

The aim of this study was to compare two budesonide/formoterol maintenance doses within the budesonide/formoterol maintenance and reliever therapy concept and to identify possible patient characteristics at baseline which would predict a better response to a higher than standard maintenance dose. A total of 8,424 patients with symptomatic asthma when using an inhaled corticosteroid (ICS) with or without a long-acting β(2)-agonist were randomised to budesonide/formoterol 160/4.5 μg, one (1 × 2) or two (2 × 2) inhalations b.i.d. Patients used the same inhaler as needed for symptom relief. The primary outcome variable was time to first severe asthma exacerbation. In the total study population, the time to first severe asthma exacerbation was prolonged by 18% with 2 × 2 versus 1 × 2 (hazard ratio 0.82; p = 0.03). Lung function (peak expiratory flow) was the only statistically significant predictor of a better response to 2 × 2. The mean daily ICS doses were 737 and 463 μg in the 2 × 2 and 1 × 2 groups, respectively. In a real-life setting, budesonide/formoterol maintenance and reliever therapy at the 2 × 2 maintenance dose did prolong time to first severe exacerbation but at a higher medication load. Patients with low lung function benefited most from the higher maintenance dose.

Effect of formoterol with or without budesonide in repeated low-dose allergen challenge

The use of combination therapy in mild asthma is debated. The current authors evaluated the effects of formoterol alone and a formoterol/budesonide combination inhaler on asthma deterioration induced by repeated low-dose allergen exposure. In total, 15 subjects with intermittent allergic asthma inhaled low doses of allergen on seven consecutive weekdays in a three-period, crossover, double-blind, double-dummy comparison between formoterol 4.5 microg Turbuhaler, budesonide 160 microg/formoterol 4.5 microg Turbuhaler and placebo, each taken as two puffs 30 min after allergen dosing. The outcome variables were: provocative dose of methacholine causing a 20% fall in forced expiratory volume in one second (PD(20)), exhaled nitric oxide fraction (F(eNO)), sputum eosinophils and prostaglandin D(2), and diary card recordings of symptoms (on a scale of 0-10), short-acting beta(2)-agonist use and evening forced expiratory volume in one second (FEV(1)). With placebo treatment, allergen exposure caused significant increases in airway hyperresponsiveness (geometric mean (coefficient of variation) PD(20): 397 (98) microg before versus 168 (82) microg after), F(eNO) (mean+/-sd 46+/-31 ppb before versus 73+/-46 ppb after) and asthma symptom score (mean+/-sd 0.39+/-0.55 before versus 0.68+/-0.67 after). Budesonide/formoterol abolished these changes and significantly improved baseline FEV(1). Formoterol alone, while providing symptom relief, was no better than placebo in protecting against the allergen-induced increase in airway inflammation. Signs of deteriorating asthma, provoked by low-dose allergen, are prevented by short-term use of budesonide/formoterol but not by temporary use of formoterol alone.

A real-life cost-effectiveness evaluation of budesonide/formoterol maintenance and reliever therapy in asthma

OBJECTIVE

To evaluate direct asthma-related costs in Swedish primary care in a real-life setting.

DESIGN

12-month open-label study.

SETTING

Swedish primary care in a real-life setting.

PARTICIPANTS

1776 patients with persistent asthma.

INTERVENTIONS

Patients with persistent asthma were randomised to one of three treatments: a free adjustable combination of budesonide (100-400 microg/inhalation) and formoterol (4.5 or 9 microg/inhalation) via separate inhalers plus terbutaline as needed; budesonide/formoterol (160/4.5 microg or 80/4.5 microg, two inhalations twice daily) plus terbutaline as needed; budesonide/formoterol (160/4.5 microg or 80/4.5 microg, one inhalation twice daily or two inhalations once daily), for maintenance plus additional inhalations as needed. Doses depended on previous inhaled corticosteroid dose. Patients attended the clinic at 0, 1.5, and 12 months. Telephone interviews were conducted at 4, 6, 8, and 10 months.

MAIN OUTCOME MEASURES

The primary endpoint was direct asthma-related healthcare costs.

RESULTS

Statistically significant reductions in annual direct costs per patient were observed with budesonide/formoterol maintenance and reliever therapy compared with the free adjustable combination of budesonide and formoterol (-13%, P<0.001) and fixed-dose budesonide/formoterol plus terbutaline (-20%, P<0.001). Time to first severe exacerbation did not differ significantly across treatment groups, with a mean reduction of 28% versus the free adjustable combination of budesonide and formoterol (P=0.076). Patients receiving budesonide/formoterol maintenance and reliever therapy used a significantly lower daily dose of budesonide compared with the conventional (P<0.001).

CONCLUSIONS

This study reports direct cost savings with budesonide/formoterol maintenance and reliever therapy compared with conventional treatment regimens with at least equivalent efficacy.

Formoterol as needed with or without budesonide in patients with intermittent asthma and raised NO levels in exhaled air: A SOMA study

Patients with mild intermittent asthma sometimes show signs of inflammation, and guidelines suggesting bronchodilator therapy alone as needed may be questioned. The current study compared as-needed use of a rapid-acting beta2-agonist with as-needed use of a beta2-agonist and corticosteroid combination as the only medication in asthma patients with intermittent symptoms. A total of 92 nonsmoking asthma patients (of 187 screened) using only an inhaled beta2-agonist as needed (28 males, 64 females; mean age 37 yrs; mean forced expiratory volume in one second (FEV1) 101% predicted, mean reversibility 6.5% pred and fractional exhaled nitric oxide (FeNO) > or =20 parts per billion (ppb)) were randomised to treatment with formoterol (Oxis Turbuhaler) 4.5 microg as needed (n = 47) or budesonide/formoterol (Symbicort Turbuhaler) 160/4.5 microg as needed (n = 45) in a double-blind, parallel-group 24-week study. The primary variable of efficacy was change in FeNO. Baseline FeNO was 60 ppb and 59 ppb in the budesonide/formoterol and formoterol groups, respectively. Mean reductions in FeNO in the budesonide/formoterol and formoterol groups were 18.2 ppb and 2.8 ppb, respectively (95% confidence interval (CI) 7.5-23.5 ppb). The reduction in the budesonide/formoterol group occurred during the first 4 weeks of treatment and remained at this low level. Mean FEV1 increased by 1.8% pred normal value in the budesonide/formoterol group and decreased by 0.9% pred normal value in the formoterol group (95% CI -4.7- -0.7). In the budesonide/formoterol group, use of > or =4 inhalations x day(-1) of study medication was seen on 21 treatment days compared with 74 in the formoterol group. In conclusion, as-needed use of an inhaled corticosteroid together with a rapid-acting bronchodilator may be more beneficial than a beta2-agonist alone in patients with intermittent asthma and signs of airway inflammation. The long-term benefits are unknown.

Budesonide/formoterol adjustable maintenance dosing reduces asthma exacerbations versus fixed dosing

A guided, adjustable-dosing regimen with budesonide/formoterol was investigated in asthma patients. In a randomised, open, multicentre study, 1034 patients received budesonide/ formoterol (Symbicort, Turbuhaler,) 80/4.5 microg or 160/4.5 microg (depending on pre-study inhaled corticosteroid dose) two inhalations twice daily for four weeks, followed by adjustable or fixed maintenance dosing for six months. Patients receiving adjustable dosing stepped down to one inhalation twice daily if symptoms were controlled and could, if symptoms worsened, step up to four inhalations twice daily for one or two weeks according to a self-guided management plan. The primary efficacy variable was occurrence of exacerbations. Compared with fixed dosing, adjustable dosing was associated with fewer patients experiencing exacerbations (6.2% vs 9.5%, NNT 30, p<0.05), fewer daily inhalations of budesonide/formoterol (2.35 vs 3.95, p<0.001), lower costs (six-month saving Euros 98, p<0.001) and was similarly well tolerated. Adjustable maintenance dosing with budesonide/formoterol provides more effective asthma control than fixed dosing, and reduces costs.

Once-daily budesonide/formoterol in a single inhaler in adults with moderate persistent asthma

Patients with moderate persistent asthma (n = 523; mean FEV1 77.4%) not fully controlled with inhaled corticosteroids (ICS; 400-1000 microg/day) were randomized to receive either once-daily budesonide/formoterol (160/4.5 microg, two inhalations); or twice-daily budesonide/formoterol (160/4.5 microg, one inhalation); or budesonide (400 microg) once-daily for 12 weeks. Once-daily dosing was administered in the evening and twice-daily dosing was administered in the morning and evening. All patients received twice-daily budesonide (200 microg) during a 2-week run-in. Compared with budesonide alone, change in mean morning and evening peak expiratory flow was greater in the once-daily budesonide/formoterol group (27 and 171 min(-1), respectively; P < 0.001) and twice-daily budesonide/formoterol group (23 and 24 l min(-1), respectively; P < 0.001). Night awakenings, symptom-free days, reliever-use-free days and asthma-control days were all improved during once-daily budesonide/formoterol therapy vs. budesonide (P < or = 0.05). Similar improvements were also seen with twice-daily budesonide/formoterol (P < or = 0.05). The risk of a mild exacerbation was reduced after once- and twice-daily budesonide/formoterol vs. budesonide (38% and 35%, respectively; P < 0.002). All treatments were well tolerated. Budesonide/formoterol, once- or twice-daily, in a single inhaler improved asthma symptoms and exacerbations compared with budesonide. In the majority of patients with moderate persistent asthma requiring ICS and long-acting beta-agonists, once-daily formoterol/budesonide provided sustained efficacy over 24 h, similar to twice-daily dosing.

Asthma care and factors affecting medication compliance: the patient's point of view

OBJECTIVE

To identify important factors that can influence patient compliance with prescribed medication and to elucidate aspects of asthma care from the patient's point of view.

DESIGN

Field investigation; the interviewer used a semi-structured questionnaire.

SETTING

Patients with asthma in primary health care settings in Sweden.

STUDY PARTICIPANTS

A sample of 77 patients was randomly selected from 11 primary health care centres in southern Sweden; 63 of these patients participated in the study.

CONCLUSION

The factors of importance for self-reported compliance with prescribed medication were age, gender, duration of the disease, the attitude of the staff and information/education about asthma. The patients expressed important aspects of care, and these are in accordance with how an asthma nurse practice functions in Sweden.

A cost-effectiveness study comparing the as-needed use of formoterol (Oxis) and terbutaline (Bricanyl) in patients with moderate to severe asthma

This study evaluated the economic and health-related consequences of the as-needed use of a long-acting beta2-agonist with fast onset (formoterol, Oxis Turbuhaler 4.5 microg) versus a short-acting beta2-agonist (terbutaline, Bricanyl Turbuhaler 0.5 mg) in patients with moderate to severe asthma. A multi-national (Sweden, Norway, The Netherlands and Greece), multi-centre (35 centres), randomized, double-blind clinical trial was conducted using 362 patients on inhaled steroids during a 12-week period. The effectiveness results were pooled and the total costs included estimates for beta2-agonists, inhaled steroids, oral steroids, physician visits and sick-leave. The 182 patients in the formoterol group had 14,404 days of exposure and 29 severe exacerbations, and the 180 patients in the terbutaline group had 13,655 days of exposure and 48 severe exacerbations. The terbutaline group had 62% more severe exacerbations than the formoterol group (P=0.039), based on exposure time. Per patient, the calculated total costs were SEK 3386 for the formoterol group and SEK 3709 for the terbutaline group over the 12-week period. The conclusion is that the use of Oxis Turbuhaler instead of Bricanyl Turbuhaler for as-needed treatment is a more effective treatment generating cost savings from a societal perspective.

Improved asthma control with budesonide/formoterol in a single inhaler, compared with budesonide alone

Budesonide/formoterol in a single inhaler was compared with budesonide alone, and with concurrent administration of budesonide and formoterol from separate inhalers, in patients with asthma, not controlled with inhaled glucocorticosteroids alone. In this 12-week, double-blind, randomized, double-dummy study, 362 adult asthmatics (forced expiratory volume in one second 73.8% of predicted, inhaled glucocorticosteroid dose 960 microg x day(-1)) received single inhaler budesonide/formoterol (Symbicort Turbuhaler) 160/4.5 microg, two inhalations b.i.d., or corresponding treatment with budesonide, or budesonide plus formoterol via separate inhalers. There was a greater increase in morning peak expiratory flow (PEF) with single-inhaler (35.7 L x min(-1)) and separate-inhaler (32.0 L x min(-1)) budesonide and formoterol, compared with budesonide alone (0.2 L x min(-1); p<0.001, both comparisons); the effect was apparent after 1 day (p<0.001 versus budesonide, both comparisons). Similarly, evening PEF, use of rescue medication, total asthma symptom scores and percentage of symptom-free days improved more with both single inhaler and separate inhaler therapy than with budesonide alone, as did asthma control days (approximately 15% more, p<0.001 versus budesonide, both comparisons, with a marked increase in the first week). All treatments were well tolerated and the adverse event profile was similar in all three treatment groups. It is concluded that single inhaler therapy with budesonide and formoterol is a clinically effective and well-tolerated treatment for patients with asthma that is not fully controlled by inhaled glucocorticosteroids alone.

Comparison of formoterol and terbutaline for as-needed treatment of asthma: a randomised trial

BACKGROUND

Asthma guidelines recommend that long-acting inhaled beta-agonists should be used as maintenance therapy for patients with asthma inadequately controlled on an inhaled corticosteroid. We studied the safety and efficacy of the long-acting beta-agonist formoterol compared with terbutaline, each taken as needed, in patients with moderate to severe asthma.

METHODS

Patients were taking an inhaled corticosteroid (mean dose 870 microg daily) and had a forced expiratory volume in 1 s (FEV1) of at least 50% predicted (mean 74%). Those requiring an inhaled beta-agonist three to eight times a day during the study run-in period (362 of 621 who started) were randomly assigned formoterol 4.5 microg or terbutaline 0.5 mg as needed by Turbuhaler in daily doses up to 54 microg and 6 mg, respectively, for 12 weeks in a double-blind, parallel-group study. Analyses were by intention to treat.

FINDINGS

The 362 randomised patients (157 men, 205 women) had a mean age of 47 years. Patients taking formoterol had a longer time to their first severe asthma exacerbation (relative-risk ratio 0.55 [95% CI 0.34-0.89]), took fewer inhalations of study drug, and had larger increases in FEV1 (5%) and morning and evening peak expiratory flow (mean difference in increase 11 L/min and 8 L/min) than those taking terbutaline. No safety issues were identified.

INTERPRETATION

When taken as needed, formoterol 4.5 microg provided better asthma control than terbutaline 0.5 mg in patients requiring moderate doses of relief medication despite inhaled corticosteroid treatment. Safety studies should be extended to a wider population of patients with asthma.

Effects of anti-reflux surgery on chronic cough and asthma in patients with gastro-oesophageal reflux disease

This two-group prospective study evaluated the effect of anti-reflux surgery (fundoplication) on 24 patients with severe gastro-oesophageal reflux disease (GORD) and concomitant asthma (n=13) or chronic cough (n=11). Twenty-four hour oesophageal pH monitoring and lung function tests (FEV1, FVC) were done before and within 1 year after anti-reflux surgery. A diary was kept by the patient during the 4-week period prior to surgery and during 4-week periods 6 and 12 months postoperatively, with daily monitoring of peak expiratory flow rate, respiratory and reflux symptoms and medication. In non-asthmatic patients, coughing was reduced by 47% and 80% during the day and night, respectively, 12 months after surgery (P < 0.01). Concomitant hoarseness and expectoration were also significantly reduced (P<0.05). No effect on lung function was seen. In patients with asthma, small, non-significant reductions in asthma symptom scores and consumption of rescue medication were seen. Twenty-two patients were completely free from their GORD symptoms after surgery. In conclusion, anti-reflux surgery in patients with GORD had a more favourable effect on concomitant cough than concomitant asthma.

Patient questionnaires in primary health care. Validation of items used in asthma care

OBJECTIVE

To evaluate each item in a patient questionnaire for the purpose of investigating whether the validity of each item is acceptable.

DESIGN

The questionnaire was completed by the patients at an ordinary follow-up visit for their asthma, and within 1 week a nurse interviewed them by telephone with the aim of analysing the validity of each item through the use of predetermined criteria.

SETTINGS

Patients with asthma in primary health care settings in Sweden.

STUDY PARTICIPANTS

Fifty-one patients were consecutively included from three different primary health care units.

RESULTS

Nine of 13 items had an acceptable validity. The four items that were not found to have acceptable validity were developed further.

CONCLUSION

Evaluating each item in a questionnaire by means of interviews with the specific patient population is a useful method of assuring that the intention of the patient questionnaire has been met.

Asthma nurse practice--a resource-effective approach in asthma management

The objective of this study was to evaluate the efficacy of an Asthma Nurse Practice (ANP) in primary health care. A 12-month (September 1994-August 1995) open, prospective intervention study with pre- and post-test comparisons was performed on patients with asthma treated at a primary care centre in Sweden. Sixty-three patients with mild or moderate asthma participated and medication, structured follow-up and education in self-management at an ANP were assessed over a 12-month period. The main outcome measures assessed were pulmonary function, eosinophil cationic protein (ECP) in serum, respiratory symptoms, patient knowledge of asthma and emergency visits. ANP in primary health care increased patient knowledge of asthma and medication. The number of patients with nocturnal symptoms decreased significantly. Pulmonary function was improved: vital capacity (VC) 98-106, forced expiratory volume in 1 sec (FEV1) 93-100 and peak expiratory flow (PEF) 98-115% of predicted (P < 0.001). Variation in PEF fell from 21 to 12% (P < 0.001). ECP was significantly reduced. Visits to the emergency room were 60% fewer during the year of intervention (P < 0.01). In conclusion, patients attending an Asthma Nurse Practice, comprising a structured programme for asthma management, improve their knowledge and asthma control.

A 3-month comparison of formoterol with terbutaline via turbuhaler. A placebo-controlled study

BACKGROUND AND AIM

Oxis Turbuhaler is a new dry powder formulation of long-acting beta2-agonist formoterol. This study compared the efficacy and safety of regular use of the long-acting beta2-agonist formoterol and the short-acting terbutaline for 3 months in patients with asthma.

METHOD

After 1-week run-in, 343 patients received either formoterol 12 microg bid (F) (delivered dose of 9 microg), terbutaline 500 microg qid (T) or placebo qid, in a parallel-group, double-blind, randomized manner. They had a mean of 61% of predicted forced expiratory volume in 1 second (FEV1) and a mean reversibility of 26%. Eighty-nine percent used inhaled corticosteroids.

RESULTS

During run-in mean morning peak expiratory flow (PEF L/min) for F was 366 and 348 for T, and 344 for placebo (P). The F group improved morning PEF significantly compared with P (P = .0022) and T (P = .0001). Changes from run-in were + 18, -1.5, and +5 L/min after F, T, and P, respectively. The F group was statistically significantly better than P and T in increasing evening PEF and in reducing night-time asthma. The F and T statistically significantly reduced the use of rescue medication compared with P. The bronchodilating response to the study drug and to an additional 1.25 mg terbutaline was of the same magnitude before and throughout the study. No statistically significant treatment-by-time interaction was observed (P > .20). There were no adverse effects of clinical relevance.

CONCLUSION

Formoterol Turbuhaler, 12 microg bid, was more effective than terbutaline Turbuhaler, 0.5 mg qid, and placebo. Regular use of formoterol or terbutaline did not significantly influence the response to additional inhalation of terbutaline.

Low-dose formoterol Turbuhaler (Oxis) b.i.d., a 3-month placebo-controlled comparison with terbutaline (q.i.d.)

This study compared the efficacy of a low dose of formoterol Turbuhaler 6 micrograms b.i.d. (F) with that of terbutaline 0.5 mg q.i.d. (T), and placebo (P) from Turbuhaler. After a 2-week run-in, 397 adults with mild to moderate asthma were randomly allocated to one of the treatments for 12 weeks. During run-in, the mean morning peak expiratory flow (PEF) was 360 (F), 368 (T) and 367 1 min-1 (P). F was better than T (P = 0.014) and P (P = 0.0001) in improving morning PEF [mean changes from run-in: 20 (F), 9 (T), and 21 min-1 (P)]. F was statistically significantly more effective than either T or P in reducing asthma symptoms. F gave also statistically significantly higher evening PEF and less use of rescue medication than P. Bronchodilator response to study drugs and additional 1.25 mg terbutaline was similar before and after the 12-week treatment period. There were no adverse effects of clinical relevance. In conclusion, formoterol Turbuhaler, 6 micrograms b.i.d. was more effective in improving PEF and offered better asthma control than either terbutaline Turbuhaler, 0.5 mg q.i.d. or placebo. Regular use of formoterol did not reduce the bronchodilator response to additional terbutaline. There were no clinically relevant adverse effects.

A 6-month comparison between formoterol and salmeterol in patients with reversible obstructive airways disease

The aim of this randomized, open, parallel group study was to compare the clinical efficacy of formoterol dry powder capsule 12 micrograms b.i.d. and salmeterol dry powder 50 micrograms b.i.d. in the treatment of patients with reversible obstructive airways disease. The 6-month treatment was preceded by a 2 week run-in period. Morning pre-dose peak expiratory flow (PEF) during the last 7 days of treatment was the primary variable. Throughout the study, patients recorded morning and evening pre-dose PEF, use of rescue medication, respiratory symptoms and adverse events. Clinic visits were scheduled at monthly intervals. Of the 482 patients randomized (equal numbers in the two treatment groups), 428 completed the study. Four hundred and twenty-five patients were included in the efficacy analysis for the primary variable. For mean morning pre-dose PEF during the last 7 days of treatment, the 95% confidence interval (CI) for the treatment contrast formoterol minus salmeterol was included entirely in the pre-defined range of equivalence (CI limits = -8.69, +9.841 min-1). This was also the case for the morning PEF during the last week before each clinic visit. For mean evening pre-dose PEF, the estimated treatment contrasts showed a trend towards superiority of formoterol over salmeterol, which became statistically significant at 2, 3 and 4 months (P < 0.05; estimated contrasts 7.27, 10.45 and 10.511 min-1, respectively). No treatment group differences were found in use of rescue medication and respiratory symptom scores. The incidence of adverse events was similar in the two groups. These findings demonstrate that formoterol 12 micrograms b.i.d. and salmeterol 50 micrograms b.i.d., both formulated as dry powders, have similar long-term efficacy and safety profiles in patients with reversible obstructive airways disease.

Mammary tumours in Sprague-Dawley rats after initiation with DMBA followed by exposure to 50 Hz electromagnetic fields in a promotional scheme

In order to test whether a transient-producing intermittent magnetic field (MF) acts as a promoter in rat mammary tumour development, a study of a 50 Hz sinusoidal MF with flux densities of 0.25 and 0.5 mT was performed on female Sprague-Dawley rats. A single administration of 7 mg of 7,12-dimethyl-benz[a]anthracene (DMBA) was given by gavage to 52-day-old animals. After 1 week, exposure to an intermittent (15 s on/15 s off) transient-associated magnetic field was started. MF exposure was performed for 19 or 21 h per day up to 25 weeks, when the study was terminated. Twice a week a careful examination with palpation for tumours was done. Tumour incidence, the number of tumours per animal, tumour volume and tumour weight were recorded. A total of 70% of MF-exposed animals developed tumours. For animals exposed to DMBA alone the correspondent figure was 71.7%. No statistical differences were seen either for tumour-bearing animals or for the total number of tumours. A slightly larger total tumour weight and tumour volume was seen for animals exposed to 0.25 mT MF. These differences were not statistically significant.

Do low molecular weight heparin and dextran increase the blood loss in transurethral resection of the prostate?

OBJECTIVE

To evaluate whether the use of dextran or the combination of low molecular weight heparin and dextran increases the blood loss in elective transurethral resection for benign prostatic hyperplasia.

PATIENTS AND METHODS

This open randomized controlled study included 198 patients operated under spinal anaesthesia who were allocated to four groups differing in the combination of prophylactic treatment used for thrombosis and for the substitution of blood loss. The prophylactic treatment was either dalteparin sodium, continued each day until mobilization, or 3% Ringer dextran-60 just before operation and continued with 6% dextran-70 for 2 days post-operatively, and the volume substitute was Ringer dextran or Ringer's acetate. Thus, the four treatments (by prophylaxis and volume substitute, respectively) were dalteparin and Ringer's acetate, dalteparin and dextran, dextran and Ringer's acetate, and dextran and dextran. The haemoglobin lost to the irrigation fluid was measured and used to calculate blood loss.

RESULTS

Patients receiving dextran had a larger post-operative and total blood loss than those who did not. The need for transfusion did not differ between the treatment groups.

CONCLUSION

The combination of dalteparin and dextran was not associated with an increased blood loss above that with dextran alone.

Two dimensional protein patterns of bronchoalveolar lavage fluid from non-smokers, smokers, and subjects exposed to asbestos

BACKGROUND

Bronchoalveolar lavage (BAL) fluid contains a large number of proteins which comprise a potential resource for studying respiratory effects due to occupational and environmental exposures. A study was undertaken to compare protein patterns of BAL fluid from non-smokers, smokers, and subjects exposed to asbestos.

METHODS

BAL fluid samples were analysed with two dimensional gel electrophoresis (2-DE). The separated proteins were detected, quantified, and pattern-matched between different individuals with a computerised imaging system designed for evaluations of 2-DE patterns.

RESULTS

About 200 different protein spots were detected in each sample of BAL fluid. As is the case with blood plasma, the BAL fluid samples contained large amounts of albumin, transferrin, and immunoglobulins. Higher levels of basic proteins were found in smokers than in non-smokers, while subjects exposed to asbestos had increased amounts of several high molecular weight proteins as well as basic proteins. Lower levels of albumin and higher levels of immunoglobulins were found in smokers than in non-smokers, while higher levels of transferrin were found in asbestos exposed subjects than in unexposed subjects. Moreover, in the group exposed to asbestos differences were found between patients with pleuritis and patients with pleural plaque, and one protein spot was found only in two patients with progressive pleural disease.

CONCLUSION

These results suggest that both smokers and asbestos exposed subjects have significant changes in their airway protein expression compared with non-smokers and unexposed subjects. It is inferred that analysis of protein patterns in the BAL fluid with 2-DE may be used to detect and characterise, at a molecular level, respiratory effects due to occupational and environmental exposures.

Lack of effect of loratadine on moderate to severe asthma

BACKGROUND

Antihistamines have been shown to be effective in patients with allergic asthma, but their role in chronic and more severe asthma is uncertain.

OBJECTIVES

To evaluate whether loratadine, a selective H1 receptor antagonist, given as an adjunct to standard asthma medication would have any effect in patients with moderate-to-severe asthma.

METHODS

Thirty-five patients with moderate-to-severe asthma, most receiving inhaled steroids, were enrolled in this double-blind, crossover study. In addition to their maintenance therapy patients received either loratadine, 20 mg once daily, or placebo for 4 weeks before crossing over to the other preparation for a further 4 weeks. Variables of efficacy were daily and nocturnal respiratory symptoms, lung function (PEF, FEV1, FVC), and bronchodilator use.

RESULTS

Three subjects were withdrawn from the study because of deteriorating asthma. There was a trend in favor of loratadine treatment with regard to global assessment of drug efficacy but the difference was not statistically significant. There was no objective improvement in asthma control comparing loratadine with placebo but if each treatment week were compared with the run-in period, PEF was significantly (P < .01) improved during the initial phase of loratadine treatment. This effect gradually decreased with time, suggesting tolerance to any bronchodilatory effect of the antihistamine.

CONCLUSION

Loratadine, given as an adjunct to standard asthma therapy, has little if any role to play in the treatment of moderate-to-severe asthma.

Dose potency relationship of terbutaline inhaled via Turbuhaler or via a pressurized metered dose inhaler

OBJECTIVE

The relative dose potency of cumulative doses of terbutaline sulfate inhaled via Turbuhaler and via a pressurized metered dose inhaler was estimated with respect to lung efficacy and systemic effect.

METHODS

The study was an open, crossover, randomized, multicenter study including 31 adult patients with asthma [forced expiratory volume in one second (FEV1), 65% of predicted]. The patients inhaled terbutaline doses of 0.125, 0.125, 0.25, 0.5, 1.0, and 2.0 mg (a total of 4 mg) at 30-minute intervals. Lung function [FEV1, forced vital capacity (FVC), forced expiratory flow at 75% of FVC (FEF75%), and peak expiratory flow (PEF)], and systemic effect variables (serum potassium, tremor, pulse, blood pressure) were monitored prior to the first inhalation and 15 to 25 minutes after each inhaled dose.

RESULTS

The mean relative dose potency of terbutaline inhaled via Turbuhaler compared with pressurized metered dose inhaler was 1.5 (95% confidence interval: 1.2 to 1.8) with respect to FEV1 and serum potassium, respectively. The corresponding relative dose potencies for PEF, FVC, and FEF75% were 1.0, 1.2, and 1.6, respectively, with no statistically significant difference between the two devices. No differences between the devices were evident with regard to blood pressure and pulse.

CONCLUSION

The results suggest that Turbuhaler is more efficient in the delivery of inhaled terbutaline to the lungs compared with the conventional pressurized metered dose inhaler.

The effects of long-term oral administration of ethanol on Sprague-Dawley rats--a condensed report

For a period of 2 years Sprague-Dawley rats received 3% and 1% ethyl alcohol or an equicaloric amount of glucose in a semisynthetic liquid diet. Thereafter the tumour incidence was recorded. For male rats no neoplastic lesions were observed to be related to ethanol exposure. For females, when individual group comparisons were made, an increase in mammary gland tumours was seen for females receiving the low ethanol containing diet. In some tumour frequency comparisons the opposite, namely a decrease in the rate of incidence, was obtained. The overall information seems to indicate the absence of a carcinogenic activity of ethyl alcohol per se after long-term oral administration. Liver and bile duct injury was seen among males. Inflammatory reactions were seen among males in pancreas and for females in the clitoral gland. Hyperplasia was observed in the thyroid gland in both sexes and in the adrenal glands among females. Peripheral nerve degeneration was common in both sexes.

Intermittent 50 Hz magnetic field and skin tumor promotion in SENCAR mice

A number of epidemiological studies have indicated association between exposure to extremely low frequency electromagnetic fields and a variety of cancers, including leukaemia and brain tumours among residentially exposed children and among occupationally exposed adults. In order to test if intermittent magnetic fields (MF) act as a tumour promoter, a long-term skin carcinogenicity study of 50 Hz sinusoidal MF with flux densities of 50 muT and 0.5 mT, continuous as well as with an intermittence of 15 s on/off, was performed. Female SENCAR mice were divided into eight groups of 50 animals in each and treated according to an initiation- promotion scheme. 7,12-dimethylbenz[a] anthracene (DMBA) in acetone was applied to the dorsal skin at a subcarcinogenic dose, as an initiator and exposure to MF was performed for 19-21 h/day during 104 weeks starting 1 week after the initiator treatment. The phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) was used as a positive control for skin tumour promoting activity. Two animals from each group were assigned for skin hyperplasia analysis at 2, 6, 12, 18 and 21 months. The animals were observed daily. The appearance of skin lesions and neoplasms were carefully followed and histopathological diagnosis was made for all neoplasms present at death. The experiment was terminated after 105 weeks. DMBA-treatment alone yielded altogether two skin tumours in two tumour-bearing animals and the animals exposed to acetone alone had one skin tumour. The animals exposed to continuous fields showed no skin tumour. Five animals exposed to 0.5 mT on/off had a total of 13 skin tumours and in the group exposed to 50 microT on/off four animals had a total of four skin tumours. The on/off exposed groups differed significantly from the continuously exposed groups (P = 0.014) but the difference between the on/off exposure groups and the DMBA group was not statistically significant when tumour-bearing animals and cumulated skin tumours were compared. There was a statistically significant dose trend (P = 0.045) with flux density and Tesla-h for intermittent MF exposure for cumulated skin tumours per tumour-bearing animals. The epithelial thickness of DMBA + MF-treated animals was of the same magnitude as for DMBA-treated animals indicating that, in the case of a promoting effect being present, another mechanism than one involving sustained hyperplasia may be involved.

Structure and regulation of expression of the acetylcholinesterase gene

Acetylcholinesterase, an enzyme essential for the termination of the action of acetylcholine, is encoded by a single gene. Alternative mRNA processing gives rise to the expression of enzyme forms with three distinct carboxyl-termini. These structural differences govern the cellular disposition of the expressed enzyme but do not influence catalytic activity. Alternative polyadenylation signals give rise to distinct 3' non-coding regions which are likely to affect mRNA stability. Alternative splicing also occurs at the 5' end of the gene where two promoter regions can be identified. Hence, regulation of expression of the gene occurs at 3 levels, transcriptional through alternative promoters, translational by affecting mRNA stability and processing of distinct mRNAs and post-translationally by giving rise to distinct peptide chains which are processed differently. Recombinant DNA studies have also been extended to modifying protein structure through site-specific mutagenesis and studying the function of the mutant enzymes.

A study on skin tumour formation in mice with 50 Hz magnetic field exposure

In order to test the possibility that magnetic fields (MF) act as a tumour promoter, a long-term skin carcinogenicity study of 50 Hz sinusoidal MF with flux densities of 50 microT and 0.5 mT was performed in female NMRI mice. 7,12-dimethylbenz[a]anthracene (DMBA) in acetone was applied to the dorsal skin, as an initiator, and exposure to MF was performed for 19 (weekdays) or 21 h/day (weekends and holidays) for 103 weeks starting one week after the initiator treatment. The phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) was used as a positive control for skin tumour promoting activity. MF was also evaluated for complete carcinogenic action in groups of mice that were treated with acetone only. Six animals from each group were taken for skin hyperplasia analysis and were killed after 9, 26 and 52 weeks. The appearance of skin lesions were carefully followed and histopathological diagnosis was made for all neoplasms present at death. The statistical analyses on occurrence of skin tumour bearing animals and cumulated skin tumours, with corrections for survival did not reveal a difference between the controls and the MF exposed groups. The epithelial thickness of DMBA + MF-treated animals was of the same magnitude as for DMBA-treated animals. Leukaemia was a little more frequent among animals exposed to 0.5 mT MF compared to the control animals. However this difference was not statistically significant.

Rat liver foci study on coexposure with 50 Hz magnetic fields and known carcinogens

A study was performed to investigate possible interactions by magnetic fields (MF) with the processes of initiation and promotion of chemically induced preneoplastic lesions in rat liver. Male Sprague-Dawley rats were subjected to a 70% partial hepatectomy followed after 24 h by i.p. injection of diethylnitrosamine (DENA) as a tumour initiator. Starting one week after the DENA-treatment phenobarbital (PB) was given to promote growth of enzymatically altered foci of liver cells. MF was applied immediately after the partial hepatectomy and continued until sacrifice after 12 weeks of PB exposure. Homogenous horizontal AC magnetic fields with a frequency of 50 Hz and flux densities of 0.5 mu T or 0.5 mT were used. The rats coexposed with MF and DENA plus PB did not gain weight as much as the rats exposed to the chemical agents only. The MF-exposure also resulted in a slight reduction in size and numbers of the focal lesions. The results suggest an interaction of MF with the processes of chemical carcinogenesis either as a result of stress or depending on effects on the proliferation of preneoplastic cells.

A clinical comparison of hydrocortisone butyrate with oxytetracycline/hydrocortisone acetate-polymyxin B in the local treatment of acute external otitis

In a single blind, randomized study, 46 patients with acute external otitis were treated with either oxytetracycline/hydrocortisone with polymyxin B (TPB) or hydrocortisone-17-alpha-butyrate eardrops for 7 days. Pseudomonas pyocyanea, Staphylococcus epidermidis and Staph. aureus were the microorganisms most frequently found in the ear canal. Fungi were not found in any culture. The overall cure rate was 80%. No significant difference in therapeutic efficacy was noted between the preparations except regarding Staph. aureus, which was cultured from 17% of the patients. Although the butyrate solution did not contain any antibiotic supplement, it seemed to be more effective than TPB in treating the staphylococcal infections. These findings suggest that such other factors as the hydrogen ion concentration, the steroid potency or the vehicle per se are of importance for the successful treatment of acute external otitis.

Esophageal acid perfusion, airway function, and symptoms in asthmatic patients with marked bronchial hyperreactivity

It is believed that GER can trigger asthma by the stimulation of acid-sensitive receptors in the esophagus. The aim of this study was to determine whether esophageal acid stimulation in asthmatic patients can provoke clinically detectable bronchospasm and if a possible response is correlated to bronchial reactivity. Eight patients with chronic asthma and GER disease were investigated on three occasions with a histamine challenge test followed by acid provocation of the esophagus. Assessment of bronchial function was made by FEV1, chest auscultation, and respiratory symptoms. While symptoms and signs of bronchoconstriction induced by esophageal acid stimulation were not detected clinically on any occasion, there was a significant correlation between histamine reactivity and the subclinical bronchospasm following acid provocation. It is concluded that esophageal acid stimulation during daytime in the majority of asthmatic patients is not a strong and immediate trigger of asthma.

Increased bronchial reactivity and potentiated skin responses in hypertensive subjects suffering from coughs during ACE-inhibitor therapy

The aim of this study was to investigate whether ACE-inhibitors could influence bronchial reactivity and interfere with inflammatory skin responses. Ten hypertensive subjects, who had reacted with coughs during ACE-inhibitor therapy, were treated in a double-blind crossover fashion for two weeks with enalapril and with placebo. Enalapril reduced the PC20 value for histamine and augmented the dermal response. Circulating eosinophilic leukocyte level in venous blood dropped markedly after the histamine bronchoprovocation performed during enalapril treatment. Plasma substance P was reduced after histamine provocation performed during placebo treatment, whereas this reduction was abolished by enalapril. In this study, we have demonstrated ACE-inhibitor-induction of moderately increased bronchial reactivity in subjects with suspected ACE-inhibitor-elicited coughs. It is suggested that coughing during ACE-inhibitor therapy is due to an increased inflammatory state in the airways.

Effects of ranitidine treatment on patients with asthma and a history of gastro-oesophageal reflux: a double blind crossover study

Forty eight patients with moderate to severe asthma were enrolled in a double blind crossover study designed to evaluate the effects of ranitidine treatment, 150 mg twice daily for four weeks, on gastro-oesophageal reflux, asthma control, and bronchial reactivity. All 48 had a history of reflux symptoms and 27 had in addition reflux associated respiratory symptoms. Thirty two patients had objective evidence of acid reflux on 24 hour pH monitoring (pH of less than 4 for more than 1% of the 24 hours) and 27 patients had a positive result in the acid perfusion test. Reflux symptoms were significantly improved after ranitidine treatment. Ranitidine treatment was associated with modest improvements in nocturnal asthma and daily use of inhaled bronchodilator drugs but there was no significant change in bronchial reactivity, lung function, peak flow, or the number of eosinophils in the blood. Comparisons between the effect of ranitidine treatment on asthma control were performed between patients with and without a history of reflux associated respiratory symptoms, with and without a positive result in the acid perfusion test, and with and without objective evidence of gastro-oesophageal reflux. A history of reflux associated respiratory symptoms was the only factor that predicted an improvement in asthma control after ranitidine treatment. These results indicate that antireflux treatment will produce only small improvements in asthma control in asthmatic patients with a history of gastro-oesophageal reflux.

Gastro-oesophageal reflux and nocturnal asthma

Gastro-oesophageal (GO) reflux is believed to be a possible cause of nocturnal asthma. The aim of this study was to see if there is any correlation between the incidence of GO-reflux at night and nocturnal asthma. Thirty-seven adult patients with a history of nocturnal asthma for more than one hundred days a year and of reflux disease were evaluated using 24 h pH-monitoring of the oesophagus and measurement of peak expiratory flow (PEF) rate every hour when awake. Half of the patients suffered from severe GO-reflux at night, whilst the other half had no nocturnal reflux. Respiratory symptoms and inhalation of beta-2 agonists were recorded during the night and PEF was recorded when the patients awoke in the morning. A significant correlation was found between reflux at night and the degree of bronchial obstruction in the early morning, but not between night-time reflux and nocturnal respiratory symptoms. It would appear that GO-reflux in most asthmatics is neither a strong nor immediate trigger factor in nocturnal asthma, although it does seem to influence bronchial obstruction during the night as was demonstrated by a low morning-PEF value.

Recovery of malondialdehyde in urine as a 2,4-dinitrophenylhydrazine derivative after exposure to chloroform or hydroquinone

Malondialdehyde (MDA) excretion in urine as an index for toxicological effects of chloroform and hydroquinone was evaluated. In a first series of experiments three groups of rats were used: non-pretreated rats (group I), starved rats (group II) and starved plus phenobarbital pretreated rats (group III). Chloroform (0.15 or 0.30 ml/kg, p.o.) was given as a single dose. The MDA excretion was related to the pretreatment, and in group III to liver damage. In a second series of experiments control rats were administered hydroquinone (100 or 200 mg/kg, p.o.), which induced a dose-related MDA excretion. These data indicate that the MDA assay was a selective and accurate marker for toxicological effects induced by the tested compounds.

Recovery of malondialdehyde in urine as a 2,4-dinitrophenylhydrazine derivative analyzed with high-performance liquid chromatography

Malondialdehyde (MDA) in urine was measured as a 2,4-dinitrophenylhydrazine (DNPH) derivative using high-performance liquid chromatography (HPLC) for the analysis. MDA standard coeluted with a peak obtained from rat urine after i.p. administration of MDA standard. This peak was also the only peak containing 14C after injection of a [14C]MDA standard, and was shown by mass spectrometry to contain 1-(2,4-dinitrophenyl)pyrazole, the derivative formed when MDA is treated with DNPH. Depending on the amount given (0.3-5.5 mumol), the recovery (after 24 h sampling period) in urine was 0.7-2.6%. This apparent non-linear kinetics may relate to several factors, such as dose-dependent metabolism. However, the peak urinary concentration approached the expected plasma concentration and reproducible recovery data were obtained, suggesting that MDA was passively excreted in a reasonably stable form. These data indicate that monitoring MDA excretion in urine can give useful information about lipid peroxidation in vivo.

Influence of theophylline on gastro-oesophageal reflux and asthma

The aim of the study was to determine whether gastro-oesophageal (GO)-reflux was increased by normal maintenance doses of theophylline, and if so, whether this was detrimental to lung function in asthmatic patients with symptoms of reflux. In 25 patients with moderate or severe bronchial asthma and a history of respiratory symptoms aggravated by reflux, two consecutive oesophageal 24-h pH recordings were made, one with and the other without their ordinary dose of slow release theophylline. The theophylline treatment caused a significant increase in total reflux time and reflux symptoms but did not worsen the asthma. Patients with subtherapeutic serum levels showed significant improvement in lung function and those with therapeutic serum levels did not. It is concluded that theophylline, in view of its potential to exacerbate GO-reflux, should be used with caution as maintenance therapy in asthmatic patients with GO-reflux.

Gastro-oesophageal reflux and triggering of bronchial asthma: a negative report

The aim of this study was to investigate whether a direct causal relationship exists between gastro-oesophageal (GO) reflux episodes and bronchial asthma. Forty-two patients with moderate or severe asthma and pathological GO-reflux were examined using a 24-h pH test at a proximal and a distal level of the oesophagus. Respiratory symptoms and the use of extra beta-2 agonist metered dose inhaler were recorded in a standardized protocol, and peak expiratory flow (PEF) was recorded once an hour until the patient went to bed. No association was found between reflux at either the proximal or the distal level of the oesophagus and bronchial symptoms or PEF reductions. We conclude that GO-reflux does not play an important role as an immediate trigger factor in bronchial asthma.

The effect of inhaled clonidine in patients with asthma

To study the effect of inhaled clonidine on broncho-obstruction in asthmatics, 10 patients with extrinsic asthma were broncho-provoked twice with an allergen that had been shown to give positive skin prick test results. Before the provocations, saline or clonidine (75 micrograms) was inhaled via a DeVilbiss no. 40 nebulizer. Clonidine slightly improved the basal respiratory function without significantly influencing the blood pressure. There was a reduction in the allergen-evoked broncho-obstruction by 42 to 65% after pretreatment with clonidine. The eosinophilic leukocytes in peripheral blood had a slight tendency to leave the circulatory system during the provocation preceded by the clonidine treatment. These data add further evidence to the finding that clonidine may be of interest in the treatment of broncho-obstructive diseases.

Lipid peroxidation in vivo monitored as ethane exhalation and malondialdehyde excretion in urine after oral administration of chloroform

In vivo lipid peroxidation was studied in phenobarbital pretreated rats exposed for chloroform. Lipid peroxidation was monitored as ethane exhalation or malondialdehyde (MDA) excretion in urine. A single oral dose of chloroform (0.7 ml/kg b.wt.) showed a marked increase in ethane exhalation in animals starved for 48 hours prior to chloroform treatment. This increase became evident after a lag-period of about 100 min. Pretreatment with diethylmaleate (1 ml/kg b.wt.) 1 hour prior to chloroform treatment gave a similar result. MDA excretion in urine from non-starved animals, exposed to chloroform, markedly increased after 4 hours and after 24 hours 115 nmol/kg had been excreted. In animals starved for 48 hours prior to chloroform treatment about 270 nmol/kg excreted within 24 hours. Small molecular weight thiols were measured in liver, kidneys and lungs. Chloroform decreased the thiol content of the liver by 43.2% within 100 min. while the concentration in the kidneys and the lungs were less affected. It is suggested that chloroform may act as a potent inducer of lipid peroxidation in vivo. The synergistic effects of the pretreatments and the lag phase indicate that glutathione depletion in the liver was an essential factor in this response.

Biosynthesis of dolichol and dolichylphosphate in rat hepatocytes in vivo

The biosynthesis of dolichol and dolichylmonophosphate in rat liver was studied using [3H]mevalonate as precursor. The radioactive precursor was either injected into the portal vein of the rat or added to the incubation medium containing isolated hepatocytes, followed by the isolation of microsomes and mitochondria from the liver or the hepatocytes. In both systems dolichol in microsomes was highly labeled after a short labeling period followed by a rapid decrease. During this period the labeling of mitochondrial dolichol was low. The specific radioactivity of dolichyl-P in microsomes of both systems was higher in the initial phase than in dolichol and increased further with time. The mitochondrial labeling was also increased but was at a much lower level.

Enrichment of the intracellular dolichol pool in isolated liver cells

Isolated hepatocytes were incubated with egg lecithin liposomes containing dolichol(C55), dolichol(C95), and dolichol phosphate(C55) in order to enrich intracellular membranes with these polyprenols. After incubation, the lipids were recovered from various membrane fractions and from the supernatant. The highest concentration was found in the microsomes. A part of the dolichol in microsomes, as well as in other fractions, was phosphorylated. This phosphorylation is mediated by the CTP-specific kinase that is present only on the outer surface of the microsomes and uses alpha-saturated polyprenols as substrates. The isolated microsomes enriched with dolichol in vivo exhibited increased lipid and protein glycosylation upon incubation with nucleotide sugars and it was demonstrated that the increased lipid glycosylation was due to transfer of the sugar to the exogenous incorporated dolichol.