Asthma Programme in Finland: Did the use of secondary care resources become more rational?

OBJECTIVES

The aims were to evaluate the profile of newly diagnosed adult asthma cases and the approach adopted to the secondary care management at the launch of the Finnish asthma programme in 1994 and seven years later, in 2001.

METHODS

A retrospective medical record audit was made of non-acutely referred patients with asthma in 1994 (n=165) and in 2001 (n=133). Clinical profile data, numbers of out-patient visits and periods of in-patient care before and after asthma diagnosis were gathered from referral letters and secondary care records.

RESULTS

The newly diagnosed asthma patients in 2001 were older, more obese and had more co-morbidities. The main asthma symptoms, such as dyspnoea, wheezing and cough, occurred equally in both years but were more often periodic than daily in 2001. Wheezing during auscultation was significantly less common in 2001. The diagnostic process was associated to a history of asthma in first-degree relatives (OR 5.34, 95% CI 1.12-24.49) in 1994 and a visit to a nurse prior to that to a physician (OR 3.13, 95% CI 1.17-8.37) in 2001. Secondary care visits per new case of asthma (7.3 in 1994 vs. 5.4 in 2001) and days in hospital (3.6 in 1994 vs. 0.95 in 2001) decreased significantly.

CONCLUSIONS

The profile of asthma diagnosed in secondary care indicates milder disease with more co-morbidities in 2001 than in 1994.Trends towards assigning a more active role on the part of primary care physicians and more rational use of secondary care resources in the management of asthma were found.

A 10 year asthma programme in Finland: major change for the better

BACKGROUND

A National Asthma Programme was undertaken in Finland from 1994 to 2004 to improve asthma care and prevent an increase in costs. The main goal was to lessen the burden of asthma to individuals and society.

METHODS

The action programme focused on implementation of new knowledge, especially for primary care. The main premise underpinning the campaign was that asthma is an inflammatory disease and requires anti-inflammatory treatment from the outset. The key for implementation was an effective network of asthma-responsible professionals and development of a post hoc evaluation strategy. In 1997 Finnish pharmacies were included in the Pharmacy Programme and in 2002 a Childhood Asthma mini-Programme was launched.

RESULTS

The incidence of asthma is still increasing, but the burden of asthma has decreased considerably. The number of hospital days has fallen by 54% from 110 000 in 1993 to 51 000 in 2003, 69% in relation to the number of asthmatics (n = 135 363 and 207 757, respectively), with the trend still downwards. In 1993, 7212 patients of working age (9% of 80 133 asthmatics) received a disability pension from the Social Insurance Institution compared with 1741 in 2003 (1.5% of 116 067 asthmatics). The absolute decrease was 76%, and 83% in relation to the number of asthmatics. The increase in the cost of asthma (compensation for disability, drugs, hospital care, and outpatient doctor visits) ended: in 1993 the costs were 218 million euro which had fallen to 213.5 million euro in 2003. Costs per patient per year have decreased 36% (from 1611 euro to 1031 euro).

CONCLUSION

It is possible to reduce the morbidity of asthma and its impact on individuals as well as on society. Improvements would have taken place without the programme, but not of this magnitude.

Risk factors for rehospitalisation in COPD: role of health status, anxiety and depression

The aim of the present study was to analyse the risk of rehospitalisation in patients with chronic obstructive pulmonary disease and associated risk factors. This prospective study included 416 patients from a university hospital in each of the five Nordic countries. Data included demographic information, spirometry, comorbidity and 12 month follow-up for 406 patients. The hospital anxiety and depression scale and St. George's Respiratory Questionnaire (SGRQ) were applied to all patients. The number of patients that had a re-admission within 12 months was 246 (60.6%). Patients that had a re-admission had lower lung function and health status. A low forced expiratory volume in one second (FEV1) and health status were independent predictors for re-admission. Hazard ratio (HR; 95% CI) was 0.82 (0.74-0.90) per 10% increase of the predicted FEV1 and 1.06 (1.02-1.10) per 4 units increase in total SGRQ score. The risk of rehospitalisation was also increased in subjects with anxiety (HR 1.76 (1.16-2.68)) and in subjects with low health status (total SGRQ score >60 units). When comparing the different subscales in the SGRQ, the closest relation between the risk of rehospitalisation was seen with the activity scale (HR 1.07 (1.03-1.11) per 4 unit increase). In patients with low health status, anxiety is an important risk factor for rehospitalisation. This may be important for patient treatment and warrants further studies.

Economic evaluation of the use of PCR assay in diagnosing pulmonary TB in a low-incidence area

To determine whether polymerase chain reaction (PCR) testing in the initial diagnosis of pulmonary tuberculosis (TB) is cost-effective in a low-prevalence population, an economic evaluation was carried out between the smear and culture (NOPCR) and smear, culture and PCR (+PCR) strategies. A decision tree model based on retrospective laboratory data was developed to assess the strategies of testing patients with suspicion of TB. Direct healthcare costs prior to confirmation of TB or nontuberculous mycobacteria by PCR or culture were included. Effectiveness was measured by the probability of correct treatment and isolation decisions. In the baseline situation NOPCR costs Euro 29.50 less than the +PCR strategy per patient tested. According to sensitivity analyses, reducing PCR test price, shortening test performance time or increasing the proportion of smear-positive patients in the tested population would contribute to cost savings with the +PCR strategy. Routine polymerase chain reaction testing of all specimens from suspected tuberculosis patients in a low-prevalence population was not cost-saving. When the polymerase chain reaction assay was applied only to smear-positive sputum specimens, the smear and culture strategy was clearly dominated by it, i.e. the polymerase chain reaction smear-positive sputum strategy was less costly and more effective in producing correct treatment decisions and isolations.

The IL1A genotype is associated with nasal polyposis in asthmatic adults

BACKGROUND

Nasal polyposis (NP) is a chronic inflammatory disease often found coexisting with asthma. As this disorder tends to cluster in families, a genetic predisposition has been suggested. Interleukin-1 (IL-1) has been proposed to play a role in the pathogenesis of NP.

METHODS

We analysed the single G-to-T base exchange polymorphism in exon 5 at +4845 of the gene encoding IL-1alpha (IL1A) and the C-to-T base exchange polymorphism at -511 of the gene encoding IL-1beta (IL1B) in a population-based sample of adult asthma patients (n = 245). The data were assessed for correlation with data on history of NP and other phenotype-related characteristics.

RESULTS

The prevalence of NP in our study group was 14.3%. The distribution of the IL1A genotype differed significantly between asthmatics with and without NP (P = 0.005). The risk of NP was markedly increased in allele G homozygous subjects (OR = 2.73; 95%CI = 1.40-5.32). In the case of IL1B we found no significant associations. Asthmatics with NP had more symptoms than others, but lung function and blood eosinophil counts were similar.

CONCLUSIONS

Our study demonstrates an association of IL1A with NP inasthmatic patients and addresses the role of IL-1alpha as an inflammatory modulator in the pathogenesis of this disease.

Mycobacterium tuberculosis complex is not detected by DNA amplification assay in sputum specimens of patients with lung scars due to past pulmonary tuberculosis

OBJECTIVE

To evaluate detection of false-positive sputum amplification assay results in former tuberculosis patients with residual pulmonary scars.

DESIGN

A total of 268 sputum specimens from 25 war veterans with tuberculosis during 1940-1959, without adequate chemotherapy, and 19 subjects effectively treated for cavitary tuberculosis during 1980-1993 were tested by smear, culture and DNA amplification, as were 34 controls with no history of tuberculosis or pulmonary scars.

RESULTS

No active tuberculosis cases were identified. All specimens were negative on DNA amplification and smear. Eight specimens from six subjects were positive on culture, revealing atypical mycobacteria.

CONCLUSION

No genetic Mycobacterium tuberculosis material in sputum specimens of subjects with residual lesions of pulmonary tuberculosis and no false-positive amplification results were detected.

No impairment of peripheral deposition in novel asthmatics treated with an MDI corticosteroid with spacer

Pulmonary distribution and lung functions were evaluated during a 4-month inhaled corticosteroid treatment period in 10 steroid-naïve novel asthmatics with normal or slightly reduced lung functions. Patients were given a total daily dose of 1000 microg of beclomethasone dipropionate aerosol twice a day via a pressured metered dose inhaler with a large-volume chamber device (Volumatic, GlaxoSmith Kline, U.K.). Gamma lung scintigraphy and lung function tests were performed before and after 2 months and 4 months. Inhaled 99mTc-labelled beclomethasone dipropionate liposomes were used to assess lung deposition patterns during inhaled steroid therapy. Serum eosinophil cationic protein (ECP) concentration was used as a surrogate marker of asthmatic inflammation. Following beclomethasone treatment, all lung functions were enhanced, but only FVC values showed significant improvement. The FEV1/FVC ratio remained slightly reduced in spite of inhaled corticosteroid therapy. However, the association between changes in improved FVC values and reduced ECP levels proved to be statistically significant. In lung scintigraphy, no evidence of changes in pulmonary deposition patterns were seen during the follow-up period. We conclude that inhaled corticosteroid therapy can lead to improvements in lung functions and surrogate markers of airway inflammation in novel asthma without affecting the peripheral deposition pattern of aerosols.

Interleukin-10 gene promoter region polymorphism is associated with eosinophil count and circulating immunoglobulin E in adult asthma

BACKGROUND

IL-10 has several functional effects relevant to asthma. It can modulate IgE production and induce apoptosis in eosinophils. Polymorphisms of IL-10 gene have been shown to affect IL-10 production.

OBJECTIVE

To establish whether IL-10 polymorphisms are associated with asthma and phenotype-related characteristics.

METHODS

The frequency of three single base exchange polymorphisms (at positions - 1082, - 819 and - 592) and corresponding haplotypes of the IL-10 gene were analysed in 245 adult asthmatic subjects and 405 controls using PCR and restriction fragment length polymorphism (RFLP). The data were assessed for correlations with the eosinophil count, serum IgE and lung function.

RESULTS

The IL-10 haplotype frequencies were similar in asthmatics and controls. Eosinophil count median was 2.0- to 3.2-fold higher among asthmatics with rare ATA/ATA genotype than in asthmatics with other genotypes. No such difference was seen in the control group. When analysed by IL-10 haplotype carrier state and gender, male asthmatics with ATA haplotype had 2.8-fold higher serum IgE than those without ATA. A converse association was found in male controls with ATA haplotype, who had 1.9-fold lower serum IgE than their ATA-negative counterparts. The high IL-10-producing GCC haplotype was associated with impaired lung function in smoking male controls while in asthmatics no clear effect on lung function was found with any of the haplotypes studied.

CONCLUSION

These results suggest that the eosinophil counts and serum IgE are differently regulated by IL-10 genotype in asthmatic and in normal subjects. However, IL-10 polymorphism is not related to susceptibility in asthma.

Possibilities of formoterol to enhance the peripheral lung deposition of the inhaled liposome corticosteroids

The pulmonary distribution and clearance of 99m-Tc-labelled beclomethasone dipropionate (Bec)--dilauroylphosphatidylcholine (DLPC) were compared in nine asthmatic patients on inhaled steroids after a 1-week medical treatment period of long-acting beta2-agonist formoterol. The patients were given formoterol 12 microg (OxisTurbuhaler) twice daily in addition to their own regular inhaled corticosteroid therapy. Gamma lung scintigraphy and lung function tests were performed before and after formoterol treatment. The bronchodilating effect ofthe combined therapy was significant: 1-week usage of inhaled formoterol enhanced peripheral lung deposition of beclomethasone liposome and thus diminished central/peripheral deposition ratio (C/P ratio). All measured lung function values except FEV1/FVC% improved after the medication period, although statistically significant levels were not reached. A systemic positive connection was seen between enhanced lung functions and greater lung deposition measured as AUC(0-24h)/24 Beclomethasone liposome formulation maintained its long-lasting effect in connection with formoterol treatment. At the 4-h measurement, 76% of the liposome-entrapped radioactivity still remained in the lungs before and 75% after the medication period.

The efficacy of a new salbutamol metered-dose powder inhaler in comparison with two other inhaler devices

An open cross-over and randomized study was carried out in order to compare the efficacy and safety of inhaled salbutamol delivered from a new 50 microg dose(-1) metered-dose dry powder inhaler Taifun, and a commercially available 50 microg dose(-1) dry powder inhaler Turbuhaler, and a conventional 100 microg dose(-1) pressurized metered-dose inhaler with a spacer (pMDI+S). Twenty-one patients, aged 21-70 years, with stable asthma and with demonstrated reversibility upon inhalation of salbutamol were included in the study. On three separate study days, the patients received a total dose of 400 microg of salbutamol from the dry powder inhalers and a dose of 800 microg from the pMDI+S in a cumulative fashion: 1,1, 2 and 4 doses at 30 min intervals. The percent change in forced expiratory volume in 1 sec (FEV1), was used as the primary efficacy variable. Salbutamol inhaled via the Taifun produced greater bronchodilation than the other devices. The difference in percent change in FEV1 between the Taifun and the other devices was statistically significant at the two first dose levels, but diminished towards the higher doses when the plateau of the dose-response curve was reached. The estimated relative dose potency of the Taifun was approximately 1.9- and 2.8-fold compared to the Turbuhaler and the pMDI+S, respectively. The Taifun caused a slight, but clinically insignificant, decrease in serum potassium concentration. There were no significant changes in the other safety parameters (blood pressure, heart rate and electrocardiogram recordings) with any of the used devices. In conclusion, this study indicates that salbutamol inhaled via the Taifun is more potentthan salbutamol inhaled from the other devices tested. In practise, a smaller total dose of salbutamol from theTaifun is needed to produce a similar bronchodilatory response. All treatments were equally well tolerated.

Evaluation of commercial DNA and rRNA amplification assays for assessment of treatment outcome in pulmonary tuberculosis patients

To evaluate the clinical utility of the DNA and RNA amplification assays in monitoring the efficacy of tuberculosis treatment, 416 sputum specimens collected from 15 smear-positive tuberculosis patients during and after treatment were tested for the presence of Mycobacterium tuberculosis by microscopy, culture, polymerase chain reaction (Cobas Amplicor Mycobacterium Tuberculosis Test; Roche, Switzerland) and AMTDT 2 (Amplified Mycobacterium Tuberculosis Direct Test; Gen Probe, USA). All patients were cured, and no relapses were found. Results of both amplification assays re mained positive longer than results of either smear or culture. Four of 15 patients were positive by polymerase chain reaction and/or AMTDT 2 at the completion of treatment. Subsequent sputum specimens from these patients converted to negative within 2.5-12 months. The present data do not support the routine use of qualitative amplification assays for monitoring the treatment response of smear-positive tuberculosis patients.

Increase of asthma in adults in northern Finland?--a report from the FinEsS study

BACKGROUND

According to previous studies, the prevalence of asthma has been lower in Finland than in other Nordic countries. In the present study, we assessed the prevalence of asthma and respiratory symptoms in northern Finland and calculated risk factors for these conditions.

METHODS

In November 1995, 7937 randomly selected subjects, 20-69 years of age, in northern Finland were invited to participate in a postal questionnaire survey. Complete answers were received from 6633 subjects (83.6%).

RESULTS

Asthma diagnosed by a physician was reported by 6.0%, while 6.3% were using asthma medicines. Asthma was most common in young adults and the elderly. The prevalence of wheezing during the previous 12 months was reported by 19.7%, while wheezing with shortness of breath apart form colds during the previous 12 months was reported by 7.1%. Only small differences between the sexes were found in prevalence of asthma and respiratory symptoms. All symptoms were strongly smoking-dependent. Sixty-three percent of men and 42% of women were current or ex-smokers. Family history of obstructive airway disease was the strongest risk factor for asthma (OR 2.9), while increasing age, smoking, and family history of obstructive airway disease were the most important risk factors for frequent wheeze.

CONCLUSIONS

The results indicate that the prevalence of asthma and symptoms associated with asthma in adults in northern Finland is now similar to that observed in Sweden and the other Nordic countries.

Comparison of the efficacy and safety of mometasone furoate dry powder inhaler to budesonide Turbuhaler

Mometasone furoate (MF) administered by dry powder inhaler (DPI) was composed with budesonide (BUD) Turbuhaler in the treatment of moderate persistent asthma. The patients were randomized to one of four treatment groups: MF DPI (100, 200, 400 microg b.i.d) or BUD Turbuhaler. 400 microg b.i.d in a 12-week, active-controlled, evaluator-blind, multicentre international trial. The primary efficacy variable was the mean change from baseline to endpoint (last treatment visit) in forced expiratory volume in one second (FEV1). Changes in FEV1 showed a statistically significant superiority (p<0.05) of MF DPI 200 and 400 microg b.i.d compared with the BUD Turbuhaler 400 microg b.i.d treatment. Significant superiority (p<0.05) was also seen in scores for several secondary efficacy variables when MF DPI was compared with BUD Turbuhaler treatment. MF DPI 200 microg b.i.d was comparable to MF DPI 400 microg b.i.d in therapeutic benefit. The incidence of oral candidiasis was no more than 3% in any group. All treatments were well tolerated. A total daily dose of 400 microg of mometasone furoate administered by dry powder inhaler provides a well-tolerated treatment for patients with moderate persistent asthma and results in a significantly greater improvement, when compared to a daily dose of 800 microg BUD Turbuhaler in the parameters measured in this study.

A new beclomethasone dipropionate multidose powder inhaler in the treatment of bronchial asthma

The clinical efficacy, tolerability and acceptability of a new multidose powder inhaler (MDPI) containing beclomethasone dipropionate (BDP) were compared with those of a BDP aerosol administered with a large volume spacer (MDI-spacer) among adult asthmatics currently receiving from 500 to 1,000 microgram/day of an inhaled corticosteroid. During the study, the dosage of BDP from both devices was 400 microgram twice daily. Ninety-one patients were randomized to the MDPI group and 42 to the MDI-spacer group. The trial was performed as an open, randomized, parallel group multicenter study. The duration of the treatment period was 12 weeks, and the study was preceded by a 2-week run-in period. During the run-in period, the mean morning peak expiratory flow (PEF) was 487 and 466 1/min in the MDPI and MDI-spacer groups, respectively. After the 12-week treatment, the morning PEF was 491 1/min in the MDPI group and 463 1/min in the MDI-spacer group. The evening values were 500 and 479 1/min during the run-in period and 496 and 476 1/min after the 12-week treatment, respectively. Asthma symptom scores and the use of rescue medication were low in both groups, indicating good efficacy of the preparations tested. The median dose of histamine required to decrease forced expiratory volume in 1 s by 15% increased during the study from 800 to 1,098 microgram in the MDPI group and from 795 to 960 microgram in the MDI-spacer group. The most frequent adverse events in both groups were hoarseness and sore throat. There were no statistically significant differences between the treatment groups in serum cortisol values or in the number of patients with thrush. Seventy-two percent of the patients regarded the MDPI easier to use while 95% considered it more portable. Over 80% of the patients felt that the MDPI was also easier to clean and as easy or easier to learn to use than the MDI-spacer. To conclude, the novel powder inhaler is well tolerated and at least equally effective as the conventional MDI-spacer combination in the treatment of asthma with BDP. However, in everyday use, patients clearly favored the powder inhaler.

Bee venom induces high histamine or high leukotriene C4 release in skin of sensitized beekeepers

Histamine is the principal mediator released in the skin during immediate bee venom allergy but the significance of cysteinyl leukotrienes in these reactions is not known. We measured skin histamine and cysteinyl leukotriene release induced by bee venom in six sensitized beekeepers with the skin microdialysis technique. The skin was dialyzed for 2 h after skin prick test with bee venom, and the release of histamine and leukotriene C4 (LTC4) into the microdialysis fractions was measured. Leukotriene E4 (LTE) and methylhistamine excretion into the urine was assayed and whole blood histamine release test was performed. The release of histamine in the skin was variable: either high delayed, high immediate and delayed, weak release or no marked release. The histamine releasability in the skin correlated with that in whole blood. The three subjects with low histamine release exhibited high LTC4 release in the skin as well as high LTE4 excretion into the urine. Thus, the histamine and LTC4 releases were inversely associated with each other. These differences may explain the variation in the clinical reaction by bee stings in sensitized beekeepers.

Serum ECP and MPO, but not urinary LTE4, are associated with bronchial hyper-responsiveness

A random population-based sample of 131 subjects was used to assess the value of serum eosinophil cationic protein (ECP), serum myeloperioxidase (MPO), and urinary leukotriene E4 (LTE4) in predicting bronchial hyper-responsiveness measured by methacholine challenge. Special interest was focused on the history of aspirin intolerance and on smoking as contributing factors. The mean serum ECP and MPO were higher in hyper-reactive [provocational dose causing a 20% fall in forced expiratory volume in 1 sec. (PD20) < or = 6900 micrograms] than in non-hyper-reactive subjects (22.3 vs. 13.2 micrograms l-1, P < 0.001 and 377 vs. 278 micrograms l-1, P = 0.001, respectively). This was also seen in current smokers vs. never smokers (17.2 vs. 12.9 micrograms l-1, P = 0.03 and 372 vs. 286 micrograms l-1, P = 0.04, respectively). There were no differences in baseline urinary excretion of LTE4 between hyper-reactive and non-hyper-reactive subjects. During the 2 h after methacholine challenge, urinary LTE4 excretion increased from 53.8 and 69.0 ng mmol-1 creatinine in non-hyper-reactive subjects, but there was no change in hyper-reactive subjects (non-hyper-reactive vs. hyper-reactive, P = 0.06). The increase was greatest in subjects with aspirin intolerance causing urticaria or angioedema but not aggravation of asthma (from 58.5 to 87.2 ng mmol-1 creatinine), probably due to extrapulmonary leukotriene production. Our results indicate that serum ECP and MPO, but not urinary LTE4 (even in subjects with a history of aspirin intolerance), predict bronchial hyper-responsiveness to methacholine. The subject's smoking history must be taken into account when these parameters are considered.

Prevalence of asthma, aspirin intolerance, nasal polyposis and chronic obstructive pulmonary disease in a population-based study

BACKGROUND

Remarkable overlap exists in symptoms between asthma and chronic obstructive pulmonary disease (COPD), and the symptoms of the patients with mild asthma are often falsely thought to be caused by smoking. The objective of the study was to determine the prevalence of doctor-diagnosed asthma, asthmatic symptoms and doctor-diagnosed COPD in an adult population. The prevalence and relation to asthma of aspirin intolerance, nasal polyposis, allergic rhinitis and smoking habits were also examined.

METHODS

Postal questionnaire survey of a population-based random sample (4300) of adult women and men aged 18-65 years served by the Päijät-Häme Central Hospital in southern Finland (a region with 208 000 inhabitants) was performed.

RESULTS

The non-response-adjusted prevalence (Drane's linear method) of doctor-diagnosed asthma was 4.4% (95% CI: 3.3-5.5%) and of COPD 3.7% (95% CI: 2.7-4.8%). The prevalence of allergic rhinitis was 37.3% (95% CI: 33.3-41.2%), and of overall aspirin intolerance 5.7% (95% CI: 4.4-7.1%). The observed prevalence of aspirin intolerance causing shortness of breath or attacks of asthma was 1.2% and it was higher in patients with doctor-diagnosed asthma than without (8.8% versus 0.8%, relative risk [RR] = 11.4, P < 0.0001), and higher in those with allergic-like rhinitis than without (2.6% versus 0.3%, RR = 7.7, P < 0.0001). The prevalence of nasal polyposis was 4.3% (95% CI : 2.8-5.8%).

CONCLUSIONS

The current prevalence of doctor-diagnosed asthma among adults is 4.4%, and allergic rhinitis, nasal polyposis and aspirin intolerance are associated with an increased risk of asthma. There is also association between aspirin-induced asthma and allergic-like rhinitis.

Autoantibodies against oxidised low-density lipoprotein in patients with obstructive sleep apnoea

Autoantibodies against oxidised low-density lipoprotein (OxLDL-Abs) have been proposed to be an indicator of endothelial dysfunction and a novel tool for finding individuals with a high cardiovascular risk. In a cross-sectional study, OxLDL-Abs were measured in 297 patients with obstructive sleep apnoea (OSA) and 54 controls using an enzyme-linked immunosorbent assay. The autoantibodies were increased in patients with OSA when compared to controls (age, body mass index (BMI) and gender adjusted, p = 0.001). However, within the OSA patients, OxLDL-Abs were not related to smoking, hypertension or BMI, and there was a weak negative correlation (r = -0.16, P = 0.007) between age and levels of OxLDL-Abs. In conclusion, at present the measurement OxLDL-Abs still remains a method for basic research and is not applicable for screening of at-risk patients with OSA.

Pulmonary distribution and clearance of two beclomethasone liposome formulations in healthy volunteers

The pulmonary distribution and clearance of 99mTc-labelled beclomethasone dipropionate (Bec) dilauroylphosphatidylcholine (DLPC) and dipalmitoylphosphatidylcholine (DPPC) liposomes were compared in 11 healthy volunteers using gamma scintigraphy. As delivered by using the Aerotech jet nebulizer both liposome aerosols had a suitable droplet size (mass median aerodynamic diameter 1.3 microm) allowing deep pulmonary deposition. However, in the total drug output during the inhalation there was a relatively large difference between DLPC and DPPC of 11.4 and 3.1 microg, respectively. In a gamma camera study no significant differences existed in the central/peripheral lung deposition between the DLPC and DPPC formulations. Progressive clearance of both Tc-labelled Bec liposomes was seen: 24 h after inhalation, 79% of the originally deposited radioactivity of DLPC liposomes and 83% of that of DPPC liposomes remained in the lungs. Thus there was slightly slower clearance of inhaled liposomes using DPPC instead of DLPC. We conclude that both liposome formulations are suitable for nebulization, although aerosol clouds were more efficiently made from the DLPC liposome suspension. Our results support the view that liposome encapsulation of a drug can offer sustained release and drug action in the lower airways.

Human plasma antioxidant capacity during radiotherapy for lung cancer: a clinical study

Even though it is well established that oxygen-free radicals are the main mechanism responsible for the cytotoxicity produced during radiotherapy, the role of the human antioxidant defense system in clinical radiation oncology is still to be clarified. Changes in the human plasma total peroxyl radical trapping capacity (TRAP) and its individual components were followed during clinical radiotherapy for lung cancer. Sixteen patients receiving radical-aimed radiotherapy provided blood samples nine times during the treatment. Our hypothesis was that oxygen-free radical production increased by irradiation should decrease the plasma TRAP as a consequence of oxidative stress. Only a moderate reduction of the plasma TRAP was found during the therapy in the study group taken as a whole, but the development pattern of TRAP and its unidentified components were clearly different in those patients showing complete or partial response to the treatment and those in which the disease progressed unabated. Plasma ascorbate levels showed no significant changes during radiotherapy. A decrease in vitamin E concentrations was seen after 6 Gy (p=0.05). Uric acid concentrations increased towards the end of the radiotherapy in both response groups (p=0.02 at 50 Gy). In this study, 26.6% of the plasma TRAP was due to unidentified antioxidants (UNID).

Effects of surgical removal of lung cancer on total plasma antioxidant capacity in lung cancer patients

Previous evidence suggests that malignant tumors cause an oxidative burden to human antioxidative defense systems. We followed the plasma total radical-trapping antioxidant parameters (TRAP) and their main antioxidant components (alpha-tocopherol, uric acid, protein sulfhydryl groups, and unidentified antioxidant proportions) in 13 lung cancer patients and 7 control patients scheduled for thoracotomy. Plasma samples were collected 9 times during a 5 month follow-up period in the cancer patients. The objective of the study was to evaluate the effects of surgical removal of lung cancer on human plasma total antioxidant capacity. A significant reduction of plasma TRAP (period effect of ANOVA, p = 0.0006) and its components appeared in both groups during the first postoperative day. This decrease was due to reduction of ascorbate (p = 0.002) alpha-tocopherol (p = 0.0001) and urate (p = 0.05) concentrations. At 3 and 5 months after the surgical removal of the tumor there was an augmentation in plasma TRAP concentrations (p = 0.02, 3 months; p = 0.07, 5 months). This was mainly due to the increases in plasma yet as unidentified antioxidant components (UNID) and protein SH-groups. The data indicates that, first, thoracotomy itself causes a reduction in plasma TRAP during the early hours after operation, and secondly surgical removal of lung cancer increases plasma TRAP concentrations compared to the baseline values possibly reflecting the relief of oxidative stress caused by malignant tumors.

Regional lung deposition and clearance of 99mTc-labeled beclomethasone-DLPC liposomes in mild and severe asthma

OBJECTIVE

To compare the distribution and clearance of inhaled beclomethasone dipropionate (Bec)-dilauroylphosphatidylcholine (DLPC) liposomes in patients with mild and severe asthma.

DESIGN

A 99mTc-labeled Bec-DLPC suspension was delivered via a nebulizer (Aerotech II). Immediately after inhalation, anterior and posterior views of the lungs and an anterior view of the oropharynx were measured by a large field gamma camera with the patient in a supine position. To evaluate the mucociliary clearance of the inhaled liposomes, anterior and posterior lung scans were repeated 1, 2, 4, and 24 h after the aerosol delivery.

PATIENTS

Ten patients with mild asthma (FEV1 >80% of the predicted) and 10 patients with severe asthma (FEV1 <60% of the predicted) were included in an open, parallel group study.

RESULTS

Clearance is more rapid among patients with severe asthma (p<0.0001). At the 4-h measurement, a mean of 82% (SD, 5.9) of the total pulmonary dose was detected in the lungs of patients with mild asthma while in those with severe asthma the figure was 69% (SD, 10.9). The ratio between central and peripheral deposition was significantly higher for patients with severe asthma than for those having a mild form of the disease; 1.07 (SD, 0.29) and 0.76 (SD, 0.07), respectively (p=0.008).

CONCLUSIONS

Inhaled Bec-DLPC liposomes were deposited more centrally in the lower airways of patients with severe asthma than those having a milder form of the disease. The clearance of Bec-DLPC liposomes is strikingly slow in both groups of asthmatic patients. However, due to the more peripheral penetration of inhaled liposomes in patients with mild asthma, the clearance rate in this group was slower than in those with severe asthma.

Clodronate is effective in preventing corticosteroid-induced bone loss among asthmatic patients

Clodronate is a novel drug used for inhibiting osteoclastic activity. The aim of the present double-blind study was to evaluate the efficacy and tolerability of clodronate (Leiras, Finland) in corticosteroid-induced bone loss among asthmatic patients. Seventy-four adult patients (41 women and 33 men, mean age 57.3 years) having a long history (mean 8.1 years) of oral and inhaled corticosteroid therapy were randomized to four parallel treatment groups: clodronate 800, 1600, or 2400 mg/day, or an identical placebo. The bone mineral density (BMD) of the lumbar spine (L2-4), femoral neck, and trochanter were assessed using dual-energy X-ray absortiometry at entry, 6 months, and 12 months. The baseline BMDs did not differ significantly between the study groups. In the lumbar spine, the mean BMD increased significantly between the baseline and 12-month visit in the clodronate groups of 1600 and 2400 mg/day, 2.6% (0.02 g/cm2, p < 0.02) and 3.0% (0.03 g/cm2, p < 0.01), respectively, but not in the placebo and clodronate 800 mg/day groups. The test for a linear trend (BMD percent change for L2-4) at 12 months was significant (p < 0.02), indicating a dose response to clodronate. The mean BMD values of the femoral neck increased significantly in the 2400 mg/day group, 4.3% (0.03 g/cm2, p < 0.0001), as well as in the trochanter region 2.8% (0.02 g/cm2, p < 0.02). Gastric irritation was the most common adverse effect noted on a clodronate dose of 2400 mg/day. We conclude that oral clodronate is effective in preventing bone loss or increasing bone mass in asthmatic patients having a long history of continuous peroral and inhaled corticosteroid administration.

Detection of Mycobacterium tuberculosis complex in sputum specimens by the automated Roche Cobas Amplicor Mycobacterium Tuberculosis Test

Three hundred twenty-four sputum specimens from 151 patients with suspected active pulmonary tuberculosis were tested for the presence of the Mycobacterium tuberculosis complex with auramine fluorochrome stain and automated PCR assay (Roche Cobas Amplicor Mycobacterium Tuberculosis Test [MTB]). The results were compared with those of the conventional Löwenstein-Jensen tube culture and the BACTEC radiometer liquid culture. A total of 76 specimens from 32 patients were culture positive for M. tuberculosis. In addition, 37 specimens from 15 patients were smear and culture positive for other Mycobacterium species but negative by the present nucleic acid amplification method and thus were not included in the comparison. Compared with culture, the sensitivities, specificities, and positive and negative predictive values for acid-fast smear were 67, 98, 93, and 91% and those for the Cobas Amplicor MTB were 83, 99, 97, and 95%, respectively. When three consecutive sputum specimens per patient could be obtained, the sensitivity of the Cobas Amplicor MTB improved to 91%, whereas the sensitivity of the acid-fast smear remained unchanged.

The bronchoprotective efficacy of salbutamol inhaled from a new metered-dose powder inhaler compared with a conventional pressurized metered-dose inhaler connected to a spacer

The aim of this study was to compare the efficacy of 100 micrograms of salbutamol inhaled from a new metered-dose powder inhaler (MDPI, Leiras Taifun, Finland) with that of a same dose of salbutamol inhaled from a conventional pressurized metered-dose inhaler with a large volume spacer (pMDI + S) in protecting against methacholine (Mch) induced bronchoconstriction. This was a 3 day, randomized, cross-over, partly blinded, placebo-controlled multicentre study where the pMDI + S was used as an open control. Twenty-six asthmatic outpatients with a baseline FEV1 > or = 60% of predicted and with bronchial hyperreactivity (PD20 FEV1 < or = 890 micrograms of Mch) were studied. On each study day the patients underwent an Mch provocation 30 min after inhaling placebo from the MDPI or a dose of 100 micrograms of salbutamol from the MDPI and from the pMDI + S. PD20 FEV1 and dose-response slope [DRS; maximal change in FEV1 (%)/dose of Mch (mumol)] were used to evaluate efficacy. The median values of PD20 FEV1 were 250, 622 and 1737 micrograms after placebo MDPI, salbutamol pMDI + S and salbutamol MDPI, respectively. The corresponding DRS values were -11.0%, -4.5% and -2.0% mumol-1. With both parameters, all differences were statistically significant (P < 0.05). In conclusion, 100 micrograms of salbutamol inhaled from Leiras Taifun MDPI offers better protection against Mch-induced bronchoconstriction than 100 micrograms of salbutamol from a pMDI connected to a large volume spacer device.

Lymphocyte subpopulations, cytokine release and specific immunoglobulin G in reactive and nonreactive beekeepers

Although bee venom sensitization and systemic sting reactions are common among beekeepers, the prediction of the severity of reactions has not yet been possible with laboratory tests. The present study was designed to evaluate parameters that might be clinically useful in estimation of systemic reactivity, and parameters that could differentiate allergic beekeepers from sensitized subjects. Thirty-two beekeepers were selected and placed into the following three groups: anergic (n = 10), asymptomatic sensitized (n = 11), and allergic (n = 11). Peripheral blood lymphocyte subpopulations, venom-specific immunoglobulin (Ig) E and IgG and cytokine release by peripheral blood mononuclear cells were measured. The ratio of stimulated interleukin-4 to stimulated interferon-gamma was significantly higher in sensitized beekeepers than in allergic or anergic subjects. Venom-specific IgG correlated significantly with the number of annual stings (r = 0.575) and the years spent in beekeeping (r = 0.471). No significant differences in the subpopulations of peripheral blood lymphocytes were found between the study groups. We conclude that differences in the subpopulations of peripheral blood lymphocytes are not associated with sensitization or systemic reactivity. In asymptomatic sensitized beekeepers, T helper 2 T-cell dominance is more pronounced than in allergic subjects. Bee venom specific IgG correlates directly with the degree of exposure to bee venom.

No relation between apolipoprotein E alleles and obstructive sleep apnea

Apolipoprotein E (ApoE) is a genetic risk factor influencing the development of cardiovascular diseases and Alzheimer's disease. Patients with obstructive sleep apnea (OSA) suffer an excess mortality and morbidity from cardiovascular diseases. The frequencies of ApoE alleles were determined in 291 patients with OSA and 728 controls. The distribution of ApoE alleles and genotypes showed no difference between OSA and controls.

A rapid dosimetric methacholine challenge in asthma diagnostics: a clinical study of 230 patients with dyspnoea, wheezing or a cough of unknown cause

The rapid methacholine challenge test using a pocket turbine spirometer (Micro Spirometer) and the Spira Elektro 2 dosimeter was performed with 230 consecutive patients who had dyspnoea, wheezing or a prolonged cough of unknown cause. Patients with previous asthma diagnoses as well as those who had used inhaled steroids during the preceding 4 weeks were excluded. Seventy-eight patients (34%) were methacholine positive (PD20FEV1 < or = 6900 micrograms) 47 (60%) of whom had a final diagnosis of American Thoracic Society (ATS) criteria fulfilling bronchial asthma. One hundred and fifty-two patients (66%) were methacholine negative (PD20FEV1 > 6900 micrograms) 14 (9%) of whom had bronchial asthma according to clinical evaluation. Increased bronchial responsiveness was strongly associated with ATS criteria fulfilling asthma (P < 0.0001). When PD20FEV1 was used, 47 (77%) of the asthmatic patients were hyper-responsive (range 40-6900 micrograms) compared to 31 (18%) of the non-asthmatic patients (range 160-6900 micrograms). When using PD15FEV1, 51 (84%) of the asthmatic patients (range 28-6900 micrograms) and 52 (31%) of the non-asthmatic patients (range 100-6900 micrograms) were hyper-responsive. The level of bronchial responsiveness measured by both PD20FEV1 and PD15FEV1 differed significantly between asthmatic and non-asthmatic patients (P < 0.0001). Hyper-responsiveness was associated with an increased daily variation in peak expiratory flow (PEF) (P < 0.0001) and an increased number of blood eosinophils (P < 0.0001). Hyper-responsiveness was also associated with decreased levels of FEV1 and percentages of predicted FEV1 (P = 0.04 and P < 0.0001, respectively). Stepwise logistic regression analysis showed that the number of positive prick results (OR = 1.15, 95% CI 1.01-1.31), blood eosinophils (1.004, 1.00-1.01), level of FEV1 (0.56, 0.36-0.87) and current smoking (2.36, 1.00-5.59) were factors significantly associated with the probability of hyper-responsiveness. Age, gender, atopy, pets and a history of ex-smoking were not significantly associated with hyper-responsiveness, neither in univariate nor in multivariate analyses. The Bayesian analysis was used to investigate the diagnostic value of the rapid methacholine challenge test. A receiver operator characteristic curve demonstrated that PD20FEV1 separated asthmatic and non-asthmatic patients better than PD15FEV1. The best cutoff value of PD20FEV1 was 6000 micrograms, but the difference from 6900 micrograms was minimal. The best results of the test using a PD20FEV1 cutoff point of 6900 micrograms (PPV: 0.80, NPV: 0.79) were obtained when the pre-test probability was 0.48. The interval security of the test was established by a pre-test probability between 0.19 and 0.78. Maximal positive (0.34) and negative (0.31) final gains were achieved when pre-test probabilities were 0.33 and 0.65, respectively. The cutoff level of 150 micrograms gave 100% of specificity and predictive value of a positive test for clinical asthma diagnosis. The Bayesian analysis approach demonstrated that the test is useful in asthma diagnostics if not performed on patients with lowest or highest probabilities of asthma.

Biomarker evidence of DNA oxidation in lung cancer patients: association of urinary 8-hydroxy-2'-deoxyguanosine excretion with radiotherapy, chemotherapy, and response to treatment

Ratios of urinary 8-hydroxy-2'-deoxyguanosine to urinary creatinine (8-OHdG/creatinine) have been considered as a good biological indicator of DNA oxidation. Urinary 8-OHdG/creatinine levels of lung cancer patients were evaluated by enzyme-linked immunosorbent assay using a monoclonal antibody N45.1 during radiotherapy and chemotherapy. An increase in urinary 8-OHdG/creatinine was found in non-small-cell carcinoma (non-SCC) patients during the course of radiotherapy. SCC patients showed higher levels of urinary 8-OHdG/creatinine than the controls. Furthermore, SCC patients with complete or partial response to the chemotherapy showed a significant decrease in urinary 8-OHdG/creatinine while patients with no change or progressive disease showed an increase.

Plasma peroxyl radical trapping capacity in lung cancer patients: a case-control study

Increasing evidence suggests that cancer patients express oxidative disturbances. The main objective of this cross-sectional case-control study (n = 57 + 76) was to explore whether lung cancer patients, when compared to healthy controls, have alterations in their plasma peroxyl radical trapping capacity (TRAP). Group matching was used with respect to age, sex and smoking history. A secondary objective was to observe the effects of life-long cigarette consumption on plasma TRAP and its components. Mean TRAP values were significantly lower in the cancer patients than in the control group (1143 vs 1273 mumol/l, p = 0.0002). Moreover, all the components of TRAP (except uric acid) were significantly lower in the cancer group: protein SH-groups 442 vs 571 mumol/l, ascorbic acid 34.0 vs 46.5 mumol/l and vitamin E 25.0 vs 33.8 mumol/l. The as yet unidentified antioxidant compounds in plasma contributed 26.5% of plasma TRAP in the cancer group and 30.2% in the control group. There was no correlation between cigarette consumption in pack-years and plasma TRAP; however, plasma concentrations of uric acid and ascorbic acid were negatively correlated with cigarette consumption.

Repeatability of a rapid dosimetric method for methacholine challenge using a pocket turbine spirometer for FEV1 measurements

The repeatability of a rapid dosimetric method for methacholine challenge was evaluated with 11 asthmatic patients. A Spira Elektro 2 dosimeter was used for methacholine delivery and a pocket turbine spirometer (Micro Spirometer) for FEV1 measurements. Methacholine was delivered in four successive, increasing doses ranging from 80 micrograms up to a cumulative dose of 6900 micrograms. The single determination standard deviation was low (12.5%), corresponding to a 95% confidence interval of +/- 0.925 doubling doses. The mean difference (+/- SE) between measurements of log PD20 FEV1 was -0.015 (0.056), and the absolute value of the difference in log PD20 FEV1 was not significantly related to the average log PD20 FEV1 (r = -0.155, P = 0.65). The rapid dosimetric methacholine challenge test, performed with a pocket turbine spirometer, proved to be as reproducible as previous methods. Furthermore, this methacholine challenge is clearly less time consuming than conventional provocations, including bronchodilator aerosol (given to resolve post-challenge bronchoconstriction); the whole test can be performed in 20 min. This is especially valuable in epidemiologic studies, as well as in clinical practice.

Effects of anthracyclin-based chemotherapy on total plasma antioxidant capacity in small cell lung cancer patients

Plasma total peroxyl radical trapping antioxidant parameters (TRAP) and their main antioxidant components (vitamin E, uric acid, protein sulfhydryl groups, and unidentified antioxidant proportions) were measured in 12 small cell lung cancer (SCLC) patients receiving combined chemotherapy consisting of vincristine, adriamycin and cyclophosphamide for SCLC. Plasma samples were collected ten times during the first two cycles of chemotherapy. There is previous evidence that many anticancer drugs exert their cytotoxity via free oxygen radicals. We hypothesized that adriamycin-induced, increased oxygen free radical production should decrease plasma TRAP as a consequence of oxidative stress. A statistically significant reduction of plasma TRAP was noted 8 hours after the first adriamycin infusion. A reduction of calculated TRAP (TRAPcalc)--the sum of concentrations of individual antioxidants, corrected by their experimentally-determined stochiometric factors--appeared 3 hours after the first adriamycin infusion and continued for up to 1 week afterwards. This decrease was due to the reduction of ascorbate and urate concentrations. Total TRAP, however, recovered to initial levels after 200 hours, due to an increase in unidentified antioxidants. The second course of adriamycin. These results are in accordance with previous studies showing the formation of oxidants with the use of anthracyclines. Evidence suggests that the as yet unidentified component of TRAP (UNID) increases during the oxidative stress caused by anthracycline based chemotherapy.

Asbestos-induced visceral pleural fibrosis reduces pulmonary compliance

To determine the nature of respiratory functional impairment caused by asbestos-induced visceral pleural fibrosis (VPF) and to discover which pulmonary physiological variable best reveals it, we examined 59 asbestos-exposed construction workers having asbestos-related changes on chest radiographs. Computed tomography scans of the thorax were also performed. Visceral pleural fibrosis was diagnosed in 29 subjects: seven had only VPF, 17 had VPF and pleural plaques, and five had VPF, plaques, and asbestosis. In subjects without VPF, 23 had plaques, six had plaques and asbestosis, and one had only minor fibrotic parenchymal changes insufficient for a diagnosis of asbestosis. Flow-volume spirometry, body plethysmography, static and dynamic compliance, and pulmonary diffusing capacity for carbon monoxide were measured. The subjects with VPF had significantly lower static (p = 0.005) and dynamic (p = 0.007) compliance values than those without. Other respiratory function variables failed to show any significant differences. We conclude that the measurement of static and dynamic compliance is a useful method in assessing pulmonary function impairment caused by visceral pleural fibrosis.

Bone mineral density in asthmatic women on high-dose inhaled beclomethasone dipropionate

Inhaled corticosteroids are the cornerstone of the modern therapy for asthma. In recent years, inhaled corticosteroids have been used in higher doses than previously. This has caused concern about possible osteoporotic side-effects. We studied bone mineral densities (BMDs) in 19 non-smoking women (mean age 53 years, range 40-63) with newly diagnosed bronchial asthma and 19 voluntary healthy non-smoking women (mean age 53 years, range 43-67). In both groups, 13 subjects were postmenopausal. Patients started beclomethasone dipropionate from the spacer 500 micrograms twice daily as the sole corticosteroid therapy. BMDs were measured with dual-energy x-ray absorptiometry (DEXA) at the lumbar spine (L2-4) and at the left proximal femur (the neck, Ward's triangle and the trochanteric region). The measurements were made at baseline and 6 and 12 months thereafter. No significant changes were observed in the measured BMDs in either study group. The results show that inhaled beclomethasone dipropionate therapy 1000 micrograms/day for one year does not affect BMD. Further studies are needed to assess the effects of inhaled corticosteroid on BMD during a longer treatment period.

Bimodal effect of platelet-activating factor (PAF) on airways responsiveness in the rabbit

The role of platelet-activating factor (PAF) to increase airways responsiveness is unclear. Since PAF has unusual dose-response characteristics in vitro, this study investigated the effects of different doses or concentrations of PAF given by intravenous and aerosol administration in anesthetized rabbits. Aerosol PAF caused a dose-dependent decrease in SGL. Intravenous administration of PAF was associated with thrombocytopenia and neutropenia, whereas aerosol administration of PAF did not alter the numbers of circulatory cells. With either administration, no inflammatory cells were recovered by lavage nor was there evidence of a gross inflammatory process within the lung. Furthermore, there was no evidence of a late asthmatic response. Intravenous PAF caused a bimodal change in airways responsiveness with a significant increase in the effective concentration causing 50% of the maximal change in SGL (EC50SGL) at low doses (0.06-06 micrograms/kg h-1) and a significant decrease in EC50SGL (an increase in responsiveness) at higher doses (1.2-2.4 micrograms/kg/h-1). Aerosol PAF decreased EC50SGL significantly at the higher doses (100-250 micrograms). These changes in EC50SGL, after both administrations, were still apparent at 3 1/2 and 4 h. In conclusion PAF has a dose-dependent, biphasic, and persistent effect on airways responsiveness, which may be independent of circulating inflammatory cells.

Measurement of respiratory muscle forces based on maximal inspiratory and expiratory pressures

We measured the maximal inspiratory and expiratory pressures of 200 healthy subjects (94 men and 106 women) using a membrane manometer designed by the authors. The reference intervals for maximal inspiratory pressure in men were -5 to -15 kPa, and for maximal expiratory pressure 9-21 kPa. For women the reference intervals for maximal inspiratory pressure were -3 to -14 kPa and for maximal expiratory pressure 5-15 kPa. In clinical practice only the lower limits are significant. The differences between subjects of different ages were small, thus age has little bearing on the strength of respiratory muscles in healthy men and women.

Easyhaler, a novel multiple dose powder inhaler: clinically equivalent to salbutamol metered dose inhaler and easier to use

Twenty-one adult asthmatic patients participated in a trial to compare the clinical equivalence of a single dose of salbutamol inhaled either from a novel multiple dose powder inhaler (MDPI), Easyhaler, or from a conventional metered dose inhaler (MDI). The trial was carried out as a randomized, double-blind, crossover study. The study involved 2 study days with a 6-hour follow-up period of spirometric indices. In addition, blood pressure and heart rate were measured immediately before each lung function test. Our data indicate that salbutamol treatment with the MDPI achieves values which are equivalent to those achieved with the conventional pressurized MDI as regards improving pulmonary function and tolerability. The mean maximum forced expiratory volume in 1 s (FEV1) after the powder dose was 2.44 +/- 0.96 liters and after the aerosol dose 2.45 +/- 0.93 liters. The mean area under the curve of absolute FEV1 values was 822 +/- 340 and 829 +/- 335, respectively. The mean percent change from the baseline in FEV1, forced vital capacity and peak expiratory flow following administration of the preparations was of equal magnitude in both cases. The treatments tested had no effect on blood pressure or heart rate and were well tolerated. A further important finding was that most patients found the MDPI easier or no more difficult to use than the conventional MDI and this probably facilitates the transition from pressurized MDIs to the novel MDPI.

Interactions between synthesis of platelet-activating factor and leukotriene B4 in isolated human polymorphonuclear leukocytes

The aim of the present work was to study interactions between the synthesis of platelet-activating factor (PAF) and leukotriene B4 (LTB4) in human polymorphonuclear leukocytes (PMNs) in vitro. PAF, at nanomolar concentrations, stimulated calcium ionophore A23187-activated PMNs to release LTB4 and 5-hydroxyeicosatetraenoic acid (5-HETE). This seems to be a receptor-mediated process as it was blocked by a PAF receptor antagonist WEB 2086 (IC50 6.6 +/- 3.9 microM). Moreover, LTB4 stimulated the formation of PAF in activated PMNs. WEB 2086 did not, however, alter PMN migration towards either LTB4 or the chemotactic peptide FMLP. This suggests that the enhancement of PAF synthesis in response to LTB4 is a concomitant event rather than a mediating process in LTB4-induced chemotactic movement of PMNs. These effects are implicated in the complex network of interactions between inflammatory mediators that results accumulation and activation of PMNs in the exacerbation of inflammatory processes.

A dose-ranging study of fluticasone propionate in adult patients with moderate asthma. International Study Group

In this 4-week, multicenter, double-blind, randomized, parallel group study, the dose-effect relationship of four doses of inhaled fluticasone propionate (50, 100, 200, and 400 micrograms twice daily) was investigated and compared with beclomethasone dipropionate, 200 micrograms twice daily. A total of 672 patients with moderate asthma currently receiving 1,000 micrograms/d or less of an inhaled steroid were recruited. The study demonstrated a significant dose-related improvement in lung function with fluticasone propionate. Linear dose-related increases were observed in morning (increase per doubling dose was 4.3 L/min; 95 percent confidence interval [CI], 1.8, 6.8 L/min; p = 0.001) and evening peak expiratory flow rate (PEFR) (increase per doubling dose was 3.0 L/min; 95 percent CI, 0.5, 5.5 L/min; p = 0.017), clinic lung function (at 4 weeks, increase in percent predicted PEFR per doubling dose = 1.1 percent; 95 percent CI, 0.2, 2.1 percent; p = 0.022; increase in percent predicted FEV1 per doubling dose = 1.1 percent; 95 percent CI, 0.3, 1.9 percent; p = 0.10:increase in percent predicted FVC per doubling dose = 1.3 percent, 95 percent CI, 0.5, 2.1 percent; p = 0.001), and the percentage of symptom-free days over days 1 to 14 of treatment (increase per doubling dose = 1.9, 95 percent CI, 0.0, 3.9; p = 0.048). There was also a dose-related reduction in extra bronchodilator usage (days 1 to 14 p = 0.002; days 15 to 28 p = 0.01). In addition, there was a significant decrease in diurnal variation with increasing doses of fluticasone propionate (decrease per doubling dose = 2.0 L/min, 95 percent CI, 0.4; p = 0.024). The number of asthma exacerbations was also reduced as the dose of fluticasone propionate increased. Fluticasone propionate was well tolerated, adverse events were few, and there was a similar incidence in all groups. Furthermore, there was no evidence of any hypothalamic pituitary adrenal axis suppression. The data from the study were consistent with other clinical studies that have shown fluticasone propionate to be more potent than beclomethasone dipropionate in terms of improvement in lung function. In conclusion, this study provided evidence of a dose-related improvement in asthma control for fluticasone propionate in the dose range 100 to 800 micrograms daily, in patients with moderate asthma.

Unimodal distribution of bronchial hyperresponsiveness to methacholine in asthmatic patients

Distribution of bronchial hyperresponsiveness to methacholine was assessed in 791 consecutive patients who were referred to the outpatient clinic of the pulmonary department due to asthmatic or persistent lower airway symptoms. Bronchial asthma was diagnosed in 319 patients. Clinical sensitivity of methacholine challenge for the disease was 89 percent and specificity, 76 percent. The degree of bronchial hyperresponsiveness in the entire group of asthmatic patients was unimodally log normal distributed. Of the 82 patients with allergic rhinitis without concurrent asthma, 27 percent had bronchial hyperresponsiveness, but of a markedly lesser degree than in the hyperresponsive asthmatic patients. In 49 patients with chronic bronchitis, 22 percent had hyperresponsiveness. The present data indicate that the degree of bronchial hyperresponsiveness in asthmatic patients is unimodally distributed, supporting the view that both genetic and environmental factors have an impact upon its development. Although the degree of bronchial hyperresponsiveness in asthma is more pronounced than in allergic rhinitis or in chronic bronchitis, a marked overlap exists.

Inhaled budesonide fails to inhibit the PAF-induced increase in plasma leukotriene B4 in man

1. We studied the ability of inhaled budesonide to modulate PAF-induced acute effects in nine healthy nonsmoking volunteers. Responses in inflammatory cells and mediators in peripheral blood as well as in pulmonary function and circulation were monitored. 2. Inhalation of increasing doses of PAF (total cumulative dose of 500 micrograms) caused a rapid and profound decrease in circulating white blood cells, especially in granulocytes (P less than 0.01), which was turned to an increased number of these cells (P less than 0.05, P less than 0.025, respectively) in the blood samples taken 8 min after completion of the PAF challenge. No changes in the circulating platelets or their thromboxane production were found. Plasma concentrations of histamine or methylhistamine remained unchanged during PAF-inhalation, while plasma LTB4 tripled from the baseline level at 10 min (P less than 0.0005) and was returned to the pre-PAF value at 60 min. 3. PAF inhalation induced a bronchial obstruction (P less than 0.025), but no bronchial hyperresponsiveness to methacholine was found in any of our subjects when measured 24 h after the PAF challenge. Furthermore, PAF caused a decrease in systolic blood pressure (P less than 0.05). 4. Budesonide pretreatment of 400 micrograms twice daily during the preceding 5 days had no effect on any PAF-induced events measured in our study. That fact may also contradict the role of bronchial resident or alveolar cells as a source of the PAF-induced LTB4 burst in plasma. 5. We conclude that in healthy volunteers inhaled PAF induces a marked increase in plasma LTB4, which is not inhibited by inhaled budesonide.(ABSTRACT TRUNCATED AT 250 WORDS)

A population-based study of bronchial asthma in adult twin pairs

Aggregation of cases of bronchial asthma in adult twin pairs was studied in the nationwide Finnish twin cohort consisting of 13,888 adult monozygotic (MZ) and same-sex dizygotic (DZ) pairs. Cases of asthma were ascertained by record-linkage from three sources of data: death certificates from the Central Statistical Office; hospital discharges from the nationwide hospital registry; and the nationwide registry for fully reimbursed medications of the Social Insurance Institution. A diagnosis of bronchial asthma in one or more of these registers was obtained for 525 (236 men and 289 women) out of 27,776 twin individuals. Among MZ pairs, ten concordant and 138 discordant pairs were identified, while among DZ pairs, 12 concordant and 343 discordant pairs were found. In the whole sample the observed-expected ratio for the number of pairs concordant for bronchial asthma was 4.30 (95 percent confidence interval [CI], 2.06 to 7.90) in MZ pairs and 2.61 (95 percent CI, 1.35 to 4.56) in DZ pairs. Using a multifactorial threshold model, we estimated the correlation in liability to asthma as 0.425 (SE = 0.07) in MZ twins and 0.247 (SE = 0.06) in DZ twins, and we obtained a heritability estimate of 35.6 percent. The data also showed a gender difference in asthma heredity, which may, however, be due to chance events affecting the distribution of concordant pairs.

Platelet-activating factor impairs mucociliary transport and increases plasma leukotriene B4 in man

We assessed the effect of inhaled platelet-activating factor (PAF) on tracheobronchial clearance, pulmonary function and blood pressure in seven healthy volunteers. After inhalation of 500 micrograms of PAF, retention of radioaerosol in ciliated airways measured at 4 h was 80% higher than in the control recording, and the clearance was reduced by 33% (p less than 0.005). Acetylsalicylic acid (ASA) did not abolish the phenomenon. PAF also decreased forced expiratory volume in one second (FEV1) by 16% (p less than 0.01), which was markedly attenuated by acetylsalicylic acid. The decrease in blood pressure after PAF (p less than 0.01) was not influenced by acetylsalicylic acid. Plasma leukotriene B4 (LTB4) was increased at 20 min after PAF inhalation (without and with ASA: mean 240 and 299 pg.ml.1, respectively) as compared to the baseline (144 and 166 pg.ml.1) and the values at 60 min after the challenge (133 and 178 pg.ml.1; p less than 0.05 and p less than 0.01, respectively). Only three out of seven subjects showed a bronchial hyperresponsiveness to methacholine measured 24 h after PAF. The PAF-induced reduction of mucociliary transport seems to be independent of cyclo-oxygenase products of arachidonic acid metabolism. These autacoids are, however, believed to contribute to the acute bronchial obstruction after PAF inhalation. In addition, inhaled PAF causes a transient increase in plasma LTB4.

Platelet-activating factor impairs mucociliary transport and increases plasma leukotriene B4 in man

We assessed the effect of inhaled platelet-activating factor (PAF) on tracheobronchial clearance, pulmonary function and blood pressure in seven healthy volunteers. After inhalation of 500 micrograms of PAF, retention of radioaerosol in ciliated airways measured at 4 h was 80% higher than in the control recording, and the clearance was reduced by 33% (p less than 0.005). Acetylsalicylic acid (ASA) did not abolish the phenomenon. PAF also decreased forced expiratory volume in one second (FEV1) by 16% (p less than 0.01), which was markedly attenuated by acetylsalicylic acid. The decrease in blood pressure after PAF (p less than 0.01) was not influenced by acetylsalicylic acid. Plasma leukotriene B4 (LTB4) was increased at 20 min after PAF inhalation (without and with ASA: mean 240 and 299 pg.ml.1, respectively) as compared to the baseline (144 and 166 pg.ml.1) and the values at 60 min after the challenge (133 and 178 pg.ml.1; p less than 0.05 and p less than 0.01, respectively). Only three out of seven subjects showed a bronchial hyperresponsiveness to methacholine measured 24 h after PAF. The PAF-induced reduction of mucociliary transport seems to be independent of cyclo-oxygenase products of arachidonic acid metabolism. These autacoids are, however, believed to contribute to the acute bronchial obstruction after PAF inhalation. In addition, inhaled PAF causes a transient increase in plasma LTB4.

Body temperature modulates the effect of platelet-activating factor (PAF) on airways responsiveness in the rabbit

Platelet-activating factor (PAF) is a potent mediator known to cause bronchoconstriction and increase airways responsiveness. In vitro studies have shown that the effects of PAF on cell function can be very temperature-dependent. The aim of the current study was to investigate the effect of elevated body temperature on numbers of circulating cells and pulmonary function in anesthetized rabbits in response to PAF. PAF was given intravenously, at a dose of 1.2 micrograms/kg hour, whereas the control experiments were performed after the animals received a saline infusion. Alteration of airways function was assessed by measuring specific pulmonary conductance (SGL) and dose-response relationships to inhaled histamine, where airways responsiveness was expressed as the effective concentration causing 50% of maximal change in specific airways conductance (EC50SGL). The rabbits were studied at two body temperatures: a normal temperature (rectal temperature of 39.8 C), and a higher temperature (rectal temperature 41.2 degrees C). Changes in circulating inflammatory cells, plasma corticosterone concentrations and in hematocrit were also monitored, to examine some potential mechanisms which might explain why body temperature altered airways responsiveness. At the normal body temperature infusion of PAF caused a significant increase in airways responsiveness (p less than 0.025), while at the high body temperature, there was a significant decrease in responsiveness (p less than 0.025). However, at both body temperatures, a profound but similar thrombocytopenia and neutropenia was observed. While plasma corticosterone levels and hematocrit showed increases coincident with the infusion of PAF, this response was unchanged by altering body temperature. We conclude that increased body temperature reduces the effect of PAF on airways responsiveness apparently through a mechanism independent of PAF effects on hemoconcentration, plasma corticosterone or circulating inflammatory cells.

Changes in running speed, blood lactic acid concentration and hormone balance during sprint training performed at an altitude of 1860 metres

The development of results of five national level sprinters (Group A) was followed up during a training period of two weeks at an altitude of 1860 m aiming at increase of strength and speed and after it. Changes in anaerobic capacity were monitored by making blood lactic acid determinations, and occurrence of any overstrain by serum testosterone, cortisol, growth hormone and SHBG (sex hormone binding globulin) determinations. A control group (Group B) trained simultaneously according to a similar programme at sea level. Maximal 150 m running speeds increased in Group A significantly during the two weeks at the altitude of 1860 m (p less than 0.001). No such increase was observable in Group B. Maximal 300 m running speeds and maximal lactic acid concentrations after running did not increase significantly in either group. Serum hormone levels did not change significantly either, in either group. Training at an altitude of 1860 m to increase strength and speed significantly improved results at the shorter distance of 150 m but had not significant effects on anaerobic capacity or on serum testosterone, cortisol, growth hormone or SHBG levels.