Digital Care Pathway for Patients With Sleep Apnea in Specialized Care: Mixed Methods Study

BACKGROUND

Sleep apnea is a significant public health disorder in Finland, with a prevalence of 3.7%. Continuous positive airway pressure (CPAP) therapy is the first-line treatment for moderate or severe sleep apnea. From November 18, 2019, all patients who started their CPAP therapy at Oulu University Hospital were attached to a sleep apnea digital care pathway (SA-DCP) and were instructed on its use. Some patients still did not use the SA-DCP although they had started their CPAP therapy.

OBJECTIVE

We aimed to study health care professionals' (HCPs') perspectives on the SA-DCP and its usefulness for their work; whether the main targets of SA-DCP can be reached: shortening the initial guiding sessions of CPAP therapy, reducing patient calls and contact with HCPs, and improving patients' adherence to CPAP therapy; and patients' perspectives on the SA-DCP and its usefulness to them.

METHODS

Overall, 6 HCPs were interviewed in May and June 2021. The survey for SA-DCP users (58/91, 64%) and SA-DCP nonusers (33/91, 36%) was conducted in 2 phases: from May to August 2021 and January to June 2022. CPAP device remote monitoring data were collected from SA-DCP users (80/170, 47.1%) and SA-DCP nonusers (90/170, 52.9%) in May 2021. The registered phone call data were collected during 2019, 2020, and 2021. Feedback on the SA-DCP was collected from 446 patients between February and March 2022.

RESULTS

According to HCPs, introducing the SA-DCP had not yet significantly improved their workload and work practices, but it had brought more flexibility in some communication situations. A larger proportion of SA-DCP users familiarized themselves with prior information about CPAP therapy before the initial guiding session than nonusers (43/58, 74% vs 16/33, 49%; P=.02). Some patients still had not received prior information about CPAP therapy; therefore, most of the sessions were carried out according to their needs. According to the patient survey and remote monitoring data of CPAP devices, adherence to CPAP therapy was high for both SA-DCP users and nonusers. The number of patients' phone calls to HCPs did not decrease during the study. SA-DCP users perceived their abilities to use information and communications technology to be better than nonusers (mean 4.2, SD 0.8 vs mean 3.2, SD 1.2; P<.001).

CONCLUSIONS

According to this study, not all the goals set for the introduction of the SA-DCP have been achieved. Despite using the SA-DCP, some patients still wanted to communicate with HCPs by phone. The most significant factors explaining the nonuse of the SA-DCP were lower digital literacy and older age of the patients. In the future, more attention should be paid to these user groups when designing and introducing upcoming digital care pathways.

Peer reviewers' willingness to review, their recommendations and quality of reviews after the Finnish Medical Journal switched from single-blind to double-blind peer review

BACKGROUND

There is a power imbalance between authors and reviewers in single-blind peer review. We explored how switching from single-blind to double-blind peer review affected 1) the willingness of experts to review, 2) their publication recommendations, and 3) the quality of review reports.

METHODS

The Finnish Medical Journal switched from single-blind to double-blind peer review in September 2017. The proportion of review invitations that resulted in a received review report was counted. The reviewers' recommendations of "accept as is", "minor revision", "major revision" or "reject" were explored. The content of the reviews was assessed by two experienced reviewers using the Review Quality Instrument modified to apply to both original research and review manuscripts. The study material comprised reviews submitted from September 2017 to February 2018. The controls were the reviews submitted between September 2015 and February 2016 and between September 2016 and February 2017. The reviewers' recommendations and the scorings of quality assessments were tested with the Chi square test, and the means of quality assessments with the independent-samples t test.

RESULTS

A total of 118 double-blind first-round reviews of 59 manuscripts were compared with 232 single-blind first-round reviews of 116 manuscripts. The proportion of successful review invitations when reviewing single-blinded was 67%, and when reviewing double-blinded, 66%. When reviewing double-blinded, the reviewers recommended accept as is or minor revision less often than during the control period (59% vs. 73%), and major revision or rejection more often (41% vs 27%, P = 0.010). For the quality assessment, 116 reviews from the double-blind period were compared with 104 reviews conducted between September 2016 and February 2017. On a 1-5 scale (1 poor, 5 excellent), double-blind reviews received higher overall proportion of ratings of 4 and 5 than single-blind reviews (56% vs. 49%, P < 0.001). Means for the overall quality of double-blind reviews were 3.38 (IQR, 3.33-3.44) vs. 3.22 (3.17-3.28; P < 0.001) for single-blind reviews.

CONCLUSIONS

The quality of the reviews conducted double-blind was better than of those conducted single-blind. Switching to double-blind review did not alter the reviewers' willingness to review. The reviewers became slightly more critical.

Maternal smoking trajectory during pregnancy predicts offspring's smoking and substance use - The Northern Finland birth cohort 1966 study

The aim was to characterize the association of maternal smoking trajectory during pregnancy with offspring's smoking, alcohol and substance use behavior. We used the prospective Northern Finland Birth Cohort 1966 study including 11,653 mothers and their offspring followed up from mothers' mid-pregnancy to age of 46 years. Main exposure was number of smoked cigarettes per day at each month of pregnancy. Outcome measures were offspring's smoking, alcohol and drug use at age 14, starting age of smoking, ever-smoking, and smoked pack-years until age 46. Four maternal smoking trajectories during pregnancy were identified with latent class trajectory modelling, namely "non-smokers" (86.0% of mothers), "early quitters" (2.0%), "late quitters" (2.1%), and "consistent smokers" (9.9%). In comparison to non-smokers, all maternal smoking was associated with offspring's increased odds of lifetime smoking adjusted for sex of the child, father's smoking, occupational status and place of residence of family, marital status and mood of mother, and desirability of pregnancy. The consistent smoker's class was associated with offspring's number of smoked pack years by midlife (median [interquartile range]: 8.3 [1.4-17.4] vs. 4.8 [0.0-13.0], p = 0.028), and alcohol use in young age (odds ratio 1.23 [95% confidence interval 1.05-1.43]). Overall, to prevent parent-offspring transmission of smoking, the cessation support should target women planning pregnancy. Negative effects of maternal continuous smoking during pregnancy include all substance use and reach up to offspring's middle age.

Smoking effect on the ultrastructural properties of cultured lung myofibroblasts

This study aimed at an ultrastructural characterization of myofibroblasts cultured from different compartments of lung from never-smokers and smokers with or without COPD. In addition, we evaluated the expression of alpha smooth muscle actin (α-SMA), a marker for myofibroblasts, and contractile properties. Stromal cells cultured from central and corresponding peripheral or only from peripheral lung of never-smokers, smokers without COPD and COPD patients were analyzed by transmission electron microscopy (TEM), immunoelectron microscopy (IEM), Western analysis and/or by collagen gel contraction assay. TEM revealed that myofibroblasts cultured from smokers and COPD had less prominent intracellular actin filaments. We also examined fibronexus (FNX), which is a typical ultrastructural feature of myofibroblasts, and observed that patients with COPD more frequently had tandem-like FNX as compared to other samples. Western analysis showed that the samples derived from the central lung of never-smokers expressed higher levels of α-SMA than those of smokers and COPD patients. Cells from central lung were less contractile than those from peripheral lung. We conclude that myofibroblasts have variable ultrastructural and functional properties based on their localization in the lung and, moreover, these properties are affected by both smoking history and COPD.

Lifelong smoking trajectories of Northern Finns are characterized by sociodemographic and lifestyle differences in a 46-year follow-up

Smoking remains among the leading causes of mortality worldwide. Obtaining a comprehensive understanding of a population’s smoking behaviour is essential for tobacco control. Here, we aim to characterize lifelong smoking patterns and explore underlying sociodemographic and lifestyle factors in a population-based birth cohort population followed up for 46 years. Our analysis is based on 5797 individuals from the Northern Finland Birth Cohort 1966 who self-reported their tobacco smoking behaviour at the ages of 14, 31 and 46. Data on sex, education, employment, body mass index, physical activity, alcohol consumption, and substance addiction were also collected at the follow-ups. We profile each individual’s annual smoking history from the age of 5 to 47, and conduct a latent class trajectory analysis on the data. We then characterize the identified smoking trajectory classes in terms of the background variables, and compare the heaviest smokers with other classes in order to reveal specific predictors of non-smoking and discontinued smoking. Six smoking trajectories are identified in our sample: never-smokers (class size 41.0%), youth smokers (12.6%), young adult quitters (10.8%), late adult quitters (10.5%), late starters (4.3%), and lifetime smokers (20.7%). Smoking is generally associated with male sex, lower socioeconomic status and unhealthier lifestyle. Multivariable between-class comparisons identify unemployment (odds ratio [OR] 1.28–1.45) and physical inactivity (OR 1.20–1.52) as significant predictors of lifetime smoking relative to any other class. Female sex increases the odds of never-smoking and youth smoking (OR 1.29–1.33), and male sex increases the odds of adult quitting (OR 1.30–1.41), relative to lifetime smoking. We expect future initiatives to benefit from our data by exploiting the identified predictors as direct targets of intervention, or as a means of identifying individuals who may benefit from such interventions.

COPD Comorbidities Predict High Mortality - Asthma-COPD-Overlap Has Better Prognosis

The purpose of this study was to investigate the characteristics and survival of patients with COPD and asthma-COPD overlap (ACO) and how these patient groups differ from each other. We examined the impact of different comorbidities, multimorbidity, lung function and other factors have on survival in COPD and ACO patients. We also examined the causes of death to determine how many patients die of other than respiratory diseases. This retrospective study includes 214 patients with an exacerbation of COPD requiring hospitalisation during the year of 2005. The patients were followed up until the end of year 2015. The survival of ACO patients was significantly higher than COPD patients (4.7 vs. 1.7 years, p = 0.001). Poor lung function predicted worse survival in both patient groups, but the prognosis was still better in ACO patients with both FEV1 over and under 50% of predicted (median survival 8.4 years vs. 5.8 years, p < 0.001) compared to COPD (4.9 and 3.1 years, respectively). In this study setting, the negative effect of having three or more comorbidities on survival was significant in both groups. We didn't see major differences in the profiles of comorbidity patterns, in the underlying cause of deaths or in the pulmonary functions between ACO and COPD groups at the beginning of follow-up. Patients with a BMI over 25 seemed to have a trend for better survival (p = 0.055), but no differences were found between ACO and COPD groups.

Pneumonic tularaemia: experience of 58 cases from 2000 to 2012 in Northern Finland

BACKGROUND

Pneumonic tularaemia is less common clinical form of tularaemia compared with the ulceroglandular form, with only a limited number of case reports and case series in Europe. In Finland, Northern Ostrobothnia is an endemic area of tularaemia with occasional seasonal outbreaks.

METHODS

In our study, a consecutive series of 58 pneumonic tularaemia cases diagnosed and treated in Oulu University Hospital in 2000-2012 were retrospectively analysed in terms of epidemiology, clinical course, and prognosis.

RESULTS

The incidence of pneumonic tularaemia showed peaks in cycles of a few years and most cases were diagnosed in late summer or early autumn. Respiratory symptoms were absent in 47% of patients, and 7% had normal chest X-ray. The chest computed tomography (CT) was performed in 81% of patients, demonstrating variable findings associated with pneumonic tularaemia. Bronchoscopy was performed for 22 (38%) patients and four (18%) of these also proceeded into mediastinoscopy. Moreover, thoracoscopy was performed for one (2%) patient. Two (3%) patients were treated shortly in the intensive care unit (ICU) during their stay in hospital. No mortality was observed.

CONCLUSIONS

Most cases of pneumonic tularaemia are diagnosed during the seasonal outbreaks. The lack of specific symptoms often complicates the diagnosis and leads to unnecessarily invasive examinations.

Diagnosis and pharmacotherapy of stable chronic obstructive pulmonary disease: the finnish guidelines

The Finnish Medical Society Duodecim initiated and managed the update of the Finnish national guideline for chronic obstructive pulmonary disease (COPD). The Finnish COPD guideline was revised to acknowledge the progress in diagnosis and management of COPD. This Finnish COPD guideline in English language is a part of the original guideline and focuses on the diagnosis, assessment and pharmacotherapy of stable COPD. It is intended to be used mainly in primary health care but not forgetting respiratory specialists and other healthcare workers. The new recommendations and statements are based on the best evidence available from the medical literature, other published national guidelines and the GOLD (Global Initiative for Chronic Obstructive Lung Disease) report. This guideline introduces the diagnostic approach, differential diagnostics towards asthma, assessment and treatment strategy to control symptoms and to prevent exacerbations. The pharmacotherapy is based on the symptoms and a clinical phenotype of the individual patient. The guideline defines three clinically relevant phenotypes including the low and high exacerbation risk phenotypes and the neglected asthma-COPD overlap syndrome (ACOS). These clinical phenotypes can help clinicians to identify patients that respond to specific pharmacological interventions. For the low exacerbation risk phenotype, pharmacotherapy with short-acting β2 -agonists (salbutamol, terbutaline) or anticholinergics (ipratropium) or their combination (fenoterol-ipratropium) is recommended in patients with less symptoms. If short-acting bronchodilators are not enough to control symptoms, a long-acting β2 -agonist (formoterol, indacaterol, olodaterol or salmeterol) or a long-acting anticholinergic (muscarinic receptor antagonists; aclidinium, glycopyrronium, tiotropium, umeclidinium) or their combination is recommended. For the high exacerbation risk phenotype, pharmacotherapy with a long-acting anticholinergic or a fixed combination of an inhaled glucocorticoid and a long-acting β2 -agonist (budesonide-formoterol, beclomethasone dipropionate-formoterol, fluticasone propionate-salmeterol or fluticasone furoate-vilanterol) is recommended as a first choice. Other treatment options for this phenotype include combination of long-acting bronchodilators given from separate inhalers or as a fixed combination (glycopyrronium-indacaterol or umeclidinium-vilanterol) or a triple combination of an inhaled glucocorticoid, a long-acting β2 -agonist and a long-acting anticholinergic. If the patient has severe-to-very severe COPD (FEV1  < 50% predicted), chronic bronchitis and frequent exacerbations despite long-acting bronchodilators, the pharmacotherapy may include also roflumilast. ACOS is a phenotype of COPD in which there are features that comply with both asthma and COPD. Patients belonging to this phenotype have usually been excluded from studies evaluating the effects of drugs both in asthma and in COPD. Thus, evidence-based recommendation of treatment cannot be given. The treatment should cover both diseases. Generally, the therapy should include at least inhaled glucocorticoids (beclomethasone dipropionate, budesonide, ciclesonide, fluticasone furoate, fluticasone propionate or mometasone) combined with a long-acting bronchodilator (β2 -agonist or anticholinergic or both).

Slug is associated with poor survival in squamous cell carcinoma of the lung

We investigated the expression of slug in a large set of lung squamous and adenocarcinomas to determine common or dissimilar features in its expression in these two most common forms of lung cancer. To investigate slug related tumor spread we studied the expression of vimentin, claudin 1, MMP2 and MMP9 in these tumors and their relation to slug. Addition, cell invasion assays, mRNA analysis and zymographic tests were performed to study epitheliomesenchymal transition (EMT) related changes in slug blocked lung cell lines. According to the results slug expression did not significantly differ between squamous (SCC) and adenocarcinoma (AC) (P = 0.25). In SCC, slug associated with vimentin (P = 0.016). In AC, claudin 1 associated with MMP2 (P = 0.037). In SCC slug expression had a poor prognositic significance (P = 0.006) and it had independent prognostic value (P = 0.037). In AC MMP2 had a worsening impact on survival (P = 0.021) and it had independent prognostic value (P = 0.002). In cell invasion assays, slug knockdown inhibited the invasion and migration of BEAS-2B, SK-LU1 and SK-MES1 cell lines. The mRNA expression of claudin 1 was downregulated in SK-LU1 cell line. Both tumor cell lines expressed MMP2 and in SK-MES1 slug inhibited line MMP2 appeared to decrease. The results show that slug associated EMT is more pronounced in lung SCC than AC. Slug associated with vimentin in SCC and had an independent prognostic value in this tumor type. Forced slug inhibition might be one putative way of treatment of SCC of the lung.

[Irritant-induced asthma]

Irritant-induced asthma is a rare disease, usually being caused by an accidental or other exceptionally strong exposure to substances irritating the respiratory passages. High-dose inhaled corticosteroid medication is immediately started at the emergency call service. If severe exposure is suspected, it is important to monitor the patient at least for a couple of days in hospital. Immediately after the acute stage diagnostic investigations are carried out, including a metacholine or histamine challenge test, since demonstration of airway hyperreactivity is of diagnostic and prognostic significance. The asthma may remain permanent.

[Update on current care guideline: chronic obstructive pulmonary disease (COPD)]

Clinical serverity of COPD is based not only on the grade of obstruction in spirometry, but also on symptoms and risk of exacerbations. Symptoms can be defined by questionnaires, such as CAT-test (COPD assessment -test) or mMRC (modified Medical Research Council -test). Smoking cessation and physical activity are important treatment options. Pharmacological treatment is selected by symptoms, risk of exacerbations and co-occurrence of asthma and COPD. Non-invasive ventilation (NIV) is recommended in the treatment of severe hypercapnic exacerbations. Palliative treatment of end stage COPD is included in the guidelines.

[Work aggravated asthma]

One out of five working persons with asthma has work-related respiratory symptoms. When exploring the symptoms of a working-age patient it is essential to survey the job description and working conditions. Early intervention in the factors aggravating the respiratory symptoms will decrease morbidity, maintain working capacity and improve the quality of life. Occupational health service and the employer play a central role in identifying and decreasing the exposure factors in the working environment as well as in patient guidance for asthma therapy and protecting from the stimuli. The working capacity of an asthmatic person can be improved by applying vocational rehabilitation.

GASC1 expression in lung carcinoma is associated with smoking and prognosis of squamous cell carcinoma

GASC1 (gene amplified in squamous cell carcinoma 1) encodes a nuclear protein that epigenetically catalyses the lysine demethylation of histones. We investigated the expression of GASC1 in different histological subtypes of lung cancer (n=289). Percentage value of GASC1 immunohistochemical expression was evaluated separately in the nuclei and cytoplasms of epithelial cancer cells. The results were compared with clinicopathologic factors and the smoking history of the patients. In lung tumor cells, 38% of nuclei and 54% of the cytoplasms stained positive for GASC1. Adenocarcinomas expressed more GASC1 nuclear (p=0.00011) and cytoplasmic (p=0.00074) positivity than squamous cell carcinoma. Smokers displayed less nuclear and cytoplasmic GASC1 expression than non-smokers (p=0.028 and p=0.036, respectively). Similarly, patients with more cytoplasmic positive staining had fewer pack years (p=0.043). Nuclear GASC1 expression had an impairing effect on survival when all histological lung cancer types were analysed together (p=0.039) and separately in squamous cell lung carcinoma (p=0.016). The results reveal that GASC1 expression is higher in adenocarcinoma than squamous cell carcinoma. Smoking decreases GASC1 expression in tumor cells, indicating that tobacco smoke may influence the methylation of histone 3 lysine residues in lung cancer. Nonetheless, nuclear GASC1 predicts a poor prognosis, especially in squamous cell carcinoma.

Myofibroblast expression in airways and alveoli is affected by smoking and COPD

Background

Chronic obstructive pulmonary disease (COPD) is characterized by structural changes in alveoli and airways. Our aim was to analyse the numbers of alpha-smooth muscle actin (α-SMA) positive cells, as a marker of myofibroblasts, in different lung compartments in non-smokers and smokers with normal lung function or COPD.

Methods

α-SMA, tenascin-C (Tn-C) and EDA-fibronectin in alveolar level and airways were assayed by immunohistochemistry and quantified by image analysis. Immunohistochemical findings were correlated with clinical data. α-SMA protein was also analysed by Western blotting from fibroblastic cells cultured from peripheral lung of non-smokers, smokers without COPD and smokers with COPD.

Results

In many cases, the endings of the detached alveolar walls were widened, the structures of which were named as widened alveolar tips. Widened alveolar tips contained α-SMA positive cells, which were obviously myofibroblasts. There were less alveolar tips containing positive cells for α-SMA in alveoli and α-SMA positive cells in bronchioles in smokers and in COPD compared to non-smokers. The quantity of α-SMA positive cells was increased in bronchi in COPD. Tn-C was elevated in bronchi in COPD and smokers’ lung. The α-SMA protein level was 1.43-fold higher in stromal cells cultured from non-smokers than in those of smokers.

Conclusions

Myofibroblasts are localized variably in normal and diseased lung. This indicates that they have roles in both regeneration of lung and pathogenesis of COPD. The widened alveolar tips, these newly characterized histological structures, seemed to be the source of myofibroblasts at the alveolar level.

[Update on current care guidelines: asthma]

Asthma is an inflammatory disease of the lower airways. The typical symptoms of asthma are cough, wheezing and shortness of breath. Asthma is diagnosed based on measures of pulmonary function showing variable or reversible airways obstruction. The basic pharmacological treatment consists of alleviating the asthmatic inflammation with regular inhaled glucocorticoids and relieving sudden obstructions with as-needed inhaled beta2-agonists. The treatment is adjusted based on asthma control. If good control of asthma is not achieved with low to medium doses of inhaled glucocorticoids, additional control medication (inhaled long acting beta2-agonists, antileukotrienes, in adults also theophylline or tiotrohium) should be introduced.

Snail promotes an invasive phenotype in lung carcinoma

Background

Snail is a transcriptional factor which is known to influence the epitheliomesenchymal transition (EMT) by regulating adhesion proteins such as E-cadherin and claudins as well as matrix metalloproteases (MMP).

Methods

To evaluate the functional importance of snail, a transciptional factor involved in EMT in lung tumors, we investigated its expression in a large set of lung carcinomas by immunohistochemistry. Expression of snail and effects of snail knockdown was studied in cell lines.

Results

Nuclear snail expression was seen in 21% of cases this being strongest in small cell lung carcinomas (SCLC). There was significantly greater snail expression in SCLC compared to squamous cell or adenocarcinoma. Positive snail expression was associated with poor survival in the whole material and separately in squamous cell and adenocarcinomas. In Cox regression analysis, snail expression showed an independent prognostic value in all of these groups. In several cell lines knockdown of snail reduced invasion in both matrigel assay and in the myoma tissue model for invasion. The influence of snail knockdown on claudin expression was cell type specific. Snail knockdown in these cell lines modified the expression of MMP2 and MMP9 but did not influence the activation of these MMPs to any significant degree.

Conclusions

The results show that snail plays an important role in the invasive characteristics of lung carcinoma influencing the survival of the patients. Snail knockdown might thus be one option for targeted molecular therapy in lung cancer. Snail knockdown influenced the expression of claudins individually in a cell-line dependent manner but did not influence MMP expressions or activations to any significant degree.

Claudins 10 and 18 are predominantly expressed in lung adenocarcinomas and in tumors of nonsmokers

AIMS

We investigated the expression of claudins 18 and 10 in a large set of primary lung carcinomas.

METHODS AND RESULTS

Immunohistochemical expression of claudin 18 was seen in 12.7 % and claudin 10 in 12.5 % of lung carcinomas. Their expression significantly associated with each other (p<0.001). The expression of claudin 18 and 10 was most prominent in lung adenocarcinomas which displayed positivity in 21.2% and 23.4 % of cases. Female patients had more often claudin 18 and 10 positive tumors, also separately in adenocarcinomas. Interestingly, claudin 10 (p=0.036) and claudin 18 (p=0.001) were more common in tumours of nonsmokers. In adenocarcinomas claudin 18 predicted a better survival (p=0.032). In Cox multivariate analysis, claudin 18 had an independent prognostic value (p=0.027).

CONCLUSION

The results show that both claudins are most commonly expressed in lung adenocarcinomas and they are more occasionally detected in other histological tumour types. Curiously, female patients and non-smokers express these claudins more commonly suggesting that they may play a part in the carcinogenesis of tobacco unrelated carcinoma. Claudin 18 associated with a better survival in lung adenocarcinoma and had an independent prognostic value and may thus be used in the evaluation of patient prognosis.

Nuclear factor erythroid-derived 2-like 2 (Nrf2) and DJ1 are prognostic factors in lung cancer

Nuclear factor erythroid-derived 2-like 2 (Nrf2) controls the expression of several enzymes that are protective against oxidative stress. We investigated the expression of nuclear factor erythroid-derived 2-like 2, DJ1 (Nrf2 stabilizer), and sulfiredoxin in a large set of lung carcinomas. The cases were analyzed immunohistochemically with antibodies to nuclear factor erythroid-derived 2-like 2, DJ1, and sulfiredoxin with the results being compared with histologic and clinical data. Significant differences were observed in the expression of DJ1 and sulfiredoxin between various types of lung tumors, while expression of nuclear factor erythroid-derived 2-like 2 was more constant. Patients with tumors with cytoplasmic (P = .033) or nuclear (P = .003) DJ1 positivity exhibited worse survival. Separately in squamous cell carcinomas, there was a tendency toward worse survival with both cytoplasmic (P = .013) and nuclear (P = .071) DJ1 positivity. Patients with a strong nuclear factor erythroid-derived 2-like 2 expression in their tumors had worse survival (P = .006). In the Cox regression analysis, nuclear factor erythroid-derived 2-like 2 was an independent prognostic factor (P = .012) along with the T status (P = .008) and DJ1 cytoplasmic positivity (P = .028). Interestingly, smokers and ex-smokers had significantly more sulfiredoxin expression in their tumors (P < .001); and in patients receiving cytostatic drugs or radiation therapy, sulfiredoxin expression predicted a poor prognosis (P = .038). Nuclear factor erythroid-derived 2-like 2 and its stabilizing protein DJ1 affect the prognosis of patients with lung cancer by inducing an elevated stress response to oxidative damage. There were differences in the expression of sulfiredoxin and DJ1 between different lung tumor types, suggesting that the pathways involved in combating oxidative stress vary in different lung cancer types.

Associations between pre-pregnancy obesity and asthma symptoms in adolescents

Background

The high prevalence of children's asthma symptoms, worldwide, is unexplained. We examined the relation between maternal pre-pregnancy weight and body mass index (BMI), and asthma symptoms in adolescents.

Methods

Data from 6945 adolescents born within the Northern Finland Birth Cohort 1986 were used. Prospective antenatal and birth outcome data, including maternal pre-pregnancy weight and BMI, and asthma symptoms in adolescent offspring at age 15–16 years, were employed. Logistic regression analyses were performed to examine the associations between relevant prenatal factors and asthma symptoms during adolescence.

Results

Current wheeze (within the past year) was reported by 10.6% of adolescents, and physician-diagnosed asthma by 6.0%. High maternal pre-pregnancy BMI was a significant predictor of wheeze in the adolescents (increase per kilogram per square metre unit; 2.7%, 95% CI 0.9 to 4.4 for ever wheeze; 3.5%, 95% CI 1.3 to 5.8 for current wheeze), and adjusting for potential confounders further increased the risk (2.8%, 95% CI 0.5 to 5.1; 4.7%, 95% CI 1.9 to 7.7, respectively). High maternal pre-pregnancy weight, in the top tertile, also significantly increased the odds of current wheeze in the adolescent by 20% (95% CI 4 to 39), and adjusting for potential confounders further increased the risk (OR=1.52, 95% CI 1.19 to 1.95). Results were similar for current asthma. Furthermore, these significant associations were observed only among adolescents without parental history of atopy but not among those with parental history of atopy.

Conclusions

The association demonstrated here between maternal pre-pregnancy overweight and obesity, and asthma symptoms in adolescents suggests that increase in asthma may be partly related to the rapid rise in obesity in recent years.

Pneumococcal carriage is more common in asthmatic than in non-asthmatic young men

INTRODUCTION

  The aim was to investigate the prevalence of oropharyngeal carriage of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Neisseria meningitidis and beta-haemolytic streptococci among asthmatic and non-asthmatic young Finnish men and to identify putative risk factors.

OBJECTIVES

  A total of 224 asthmatics and 668 non-asthmatic men (mean age 19.6 years) from two intakes of conscripts to the Kainuu Brigade, Finland in July 2004 and January 2005 were enrolled upon entering military service.

METHODS

  Oropharyngeal specimens were examined for bacteria by routine culture methods. All the participants filled in questionnaires concerning risk factors for asthma and respiratory infections.

RESULTS

  S. pneumoniae (48 cases, 5.4%), Group A streptococci (16, 1.8%), H. influenzae (45, 5.0%), M. catarrhalis (24, 2.7%) and N. meningitidis (20, 2.2%) were isolated from the 892 participants. Ten putative risk factors for oropharyngeal colonization (asthma, atopy, allergic rhinitis, smoking, current use of asthma medication, history of adeno/tonsillectomy, level of highly sensitive C-reactive protein, peak expiratory flow, results of a 12-min running test and body mass index) were evaluated. The only significant risk factor for S. pneumoniae carriage was asthma (OR, 2.04; 95% CI 1.12 to 3.72).

CONCLUSIONS

  Pneumococcal carriage is more common in asthmatic than in non-asthmatic young men.

[Specific challenge tests in occupational asthma--guidelines by the Finnish Expert Group on Occupational Lung Diseases]

In a specific inhalation challenge (SIC) test the patient inhales an occupational agent in controlled environment and the subsequent asthmatic reaction is monitored. SIC is considered as the reference standard when confirming the diagnosis of sensitizer-induced occupational asthma. However, SIC is not always needed for the diagnosis; in many cases the causal relationship between an occupational agent and asthma can be shown also with serial peak flow measurements and specific immunologic testing. SIC is invaluable in identifying new occupational airway sensitizers. This is essential for preventing occupational asthma in the future.

[Peak expiratory flow monitoring--the basis for diagnosing occupational asthma--guidelines by the Finnish Expert Group on Occupational Lung Diseases]

Occupational exposures can cause adult-onset asthma. Early diagnosis and early avoidance of further exposure to causative agent improves the prognosis of occupational asthma. Occupational and primary care health services have an important role in the identification of new cases of occupational asthma. For the diagnosis of occupational asthma, serial peak expiratory flow (PEF) measurements should be performed in an early stage. Although it requires an effort from the patient, high quality recordings offer the best approach to assess the relationship between workplace exposure and respiratory symptoms. Good guidance and performance of serial PEF measurements in primary care is recommended and is worth the effort.

Zeb1 and twist are more commonly expressed in metastatic than primary lung tumours and show inverse associations with claudins

BACKGROUND

Zeb1 and twist regulate expression of genes which take part in epitheliomesenchymal transition (EMT). Claudins are tight junctional proteins regulating polarity and paracellular permeability of epithelial cells.

AIMS AND METHODS

To study Zeb1 and twist in 289 primary and 54 metastatic lung tumours and their relation to expression of claudins 1-5 and 7 by immunohistochemistry.

RESULTS

Metastatic tumours showed a significantly lower expression of zeb1 and twist (33.0% and 38.0% vs 5.0% and 14.5%, p<0.001 for both) and they also had a significantly lower expression of claudin 1 (p<0.001), claudin 4 (p<0.001), claudin 5 (p=0.001) and claudin 7 (p<0.001) than did primary tumours. Primary lung tumours showed a strong inverse association between zeb1 and claudin 1 (p=0.024) and claudin 2 (p=0.003). For twist an inverse association was found with claudin 5 (p=0.007). In metastatic tumours zeb1 was inversely associated with claudin 7 (p=0.050) and twist with claudin 5 (p=0.025). Overexpression of claudin 5 was associated with decreased survival (p=0.017). For zeb1 or twist, no association with survival was observed in primary or metastatic tumours.

CONCLUSIONS

According to protein expression, involvement of zeb1 and twist in EMT in primary lung tumours is relatively infrequent. Carcinomas metastatic to the lung showed a significantly higher expression of these transcriptional factors than primary lung tumours, indicating their probable importance in the metastatic process. Zeb1 and twist were inversely associated with several claudins, indicating a role in their down-regulation.

Variability in the precursor proteins of collagen I and III in different stages of COPD

Background

Levels of precursor proteins of collagen I and III are increased in fibrotic pulmonary diseases. This study determined whether the expression of precursors of type I and III collagen proteins would be increased in small and large airways of COPD patients in various stages of the disease reflecting fibrogenesis.

Methods

The levels of precursor proteins of collagen I and III were studied by immunohistochemistry and quantified by image analysis in lung tissue of 16 non-smokers, 20 smokers with normal lung function, 20 smokers with stage I-II COPD and 8 ex-smokers with stage IV COPD.

Results

In large airways, the subepithelial layer which was positive for precursor proteins of collagen I and III was thicker in smokers and in stage I-II COPD compared to non-smokers. Large airways in stage IV COPD showed reduced expression of precursor protein of collagen I whereas precursor of collagen III was increased. The amount of precursor protein of collagen III was increased in small airways of smokers and stage I-II COPD but reduced in stage IV COPD.

Conclusions

Precursor proteins of collagen I and III revealed different expression profiles in large and small airways in various stages of COPD. Smoking enhanced expression of both precursors in large airways with a positive correlation with pack-years.

Impact of smoking on the expression of claudins in lung carcinoma

RATIONALE

Tight junctions regulate the paracellular permeability and orientation of cells and claudins are key components of tight junctions.

OBJECTIVES

To study the influence of cigarette smoke on claudin expression in vitro and in lung cancer patients.

METHODS

We studied the effect of smoking on claudin expression by exposing a bronchial cell line (BEAS-2B) and two carcinoma cell lines (SK-LU1 and SK-MES1) to tobacco smoke for 48 h and analysed their claudin mRNA expression. The relation between smoked pack years and protein expression of claudins 1-5 and 7 in 344 lung cancer patients was determined by immunohistochemistry.

MEASUREMENTS AND MAIN RESULTS

In BEAS-2B cells and SK-LU1 cells, an initial increase was followed by a decline in the mRNA expression of several claudins. In SK-MES1 cells, no evident elevation in claudin expression was observed. Intense claudin 1 and 4 positivity was found more often in cancer samples of smokers and ex-smokers compared to non-smokers (p<0.001 and p=0.003, respectively). Heavy smokers with longer than 40 pack-years consumption had more often intense claudin 1 (p=0.011), 4 (p=0.050) or 7 (p=0.058) expression in squamous cell carcinoma compared to non-smokers or smokers with fewer pack-years. Claudin 1 positivity predicted a better survival in adenocarcinoma (p=0.044) and in squamous cell carcinoma (p=0.027) and claudin 4 positivity in adenocarcinoma only (p=0.048). In squamous cell carcinoma, claudin 7 positivity was associated with a better survival (p=0.011).

CONCLUSIONS

Bronchial BEAS-2B cells and SK-LU1 cells respond to tobacco smoke by changing their claudin mRNA synthesis and resulting tight junction permeability changes may thus contribute to tobacco induced carcinogenesis both during initiation and progression. This concept is strengthened by findings in the clinical tumour material, where tobacco consumption was associated with claudin expression.

Cold-related respiratory symptoms in the general population

INTRODUCTION

Cold-related respiratory symptoms are common among northern populations, especially among people suffering from respiratory diseases. However, the prevalence of such symptoms in the general population and the threshold temperatures at which the symptoms start to emerge are poorly known.

OBJECTIVES

The present study determined the prevalence and threshold temperatures of self-reported respiratory symptoms related to cold, separately for healthy people and those with respiratory disease.

MATERIALS AND METHODS

Six thousand five hundred ninety-one men and women aged 25 years-74 years from the national FINRISK study were queried about cold-related respiratory symptoms. The results were expressed as age-adjusted prevalence figures and coefficients from multivariate regressions.

RESULTS

Cold-related respiratory symptoms were more often reported by people with asthma (men 69%/women 78%) and by subjects with chronic bronchitis (65%/76%) than the healthy subjects (18%/21%). A binomial regression showed an increase of symptom prevalence by age and excesses of 4%, 50% and 21% units because of female sex, asthma and chronic bronchitis, respectively. The reported threshold temperature for cold-related symptoms was -14 degrees C for males and -15 degrees C for females, and it showed some increase by age (0 degrees C-5 degrees C), asthma (2 degrees C) and chronic bronchitis (3 degrees C). The threshold temperature for mucus production was exceptional as it decreased by age (2 degrees C-5 degrees C) and asthma (2 degrees C). The effects of smoking and education were marginal.

CONCLUSION

Cold-related respiratory symptoms are common in patients with chronic respiratory diseases, but they start to emerge at relatively low temperatures. In a cold climate, the cold-related symptoms may have an impact on the health-related quality of life.

Divergent expression of claudin -1, -3, -4, -5 and -7 in developing human lung

BACKGROUND

Claudins are the main components of tight junctions, structures which are associated with cell polarity and permeability. The aim of this study was to analyze the expression of claudins 1, 3, 4, 5, and 7 in developing human lung tissues from 12 to 40 weeks of gestation.

METHODS

47 cases were analyzed by immunohistochemistry for claudins 1, 3, 4, 5 and 7. 23 cases were also investigated by quantitative RT-PCR for claudin-1, -3 and -4.

RESULTS

Claudin-1 was expressed in epithelium of bronchi and large bronchioles from week 12 onwards but it was not detected in epithelium of developing alveoli. Claudin-3, -4 and -7 were strongly expressed in bronchial epithelium from week 12 to week 40, and they were also expressed in alveoli from week 16 to week 40. Claudin-5 was expressed strongly during all periods in endothelial cells. It was expressed also in epithelium of bronchi from week 12 to week 40, and in alveoli during the canalicular period. RT-PCR analyses revealed detectable amounts of RNAs for claudins 1, 3 and 4 in all cases studied.

CONCLUSION

Claudin-1, -3, -4, -5, and -7 are expressed in developing human lung from week 12 to week 40 with distinct locations and in divergent quantities. The expression of claudin-1 was restricted to the bronchial epithelium, whereas claudin-3, -4 and -7 were positive also in alveolar epithelium as well as in the bronchial epithelium. All claudins studied are linked to the development of airways, whereas claudin-3, -4, -5 and -7, but not claudin-1, are involved in the development of acinus and the differentiation of alveolar epithelial cells.

Smoking status interacts with the association between mannose-binding lectin serum levels and gene polymorphism and the carriage of oropharyngeal bacteria

Mannose-binding lectin (MBL) role in the carriage of oropharyngeal bacteria is not known. We investigated the association of smoking, MBL2 polymorphisms, and MBL concentrations with oropharyngeal carriage of respiratory bacteria in young men. Oropharyngeal specimens, MBL concentrations, and MBL2 gene polymorphisms were measured in 124 asthmatic and 394 nonasthmatic Finnish military recruits. The carriage rates of S. pneumoniae (p = 0.002), N. meningitidis (p = 0.005), and beta-hemolytic streptococci (p < 0.001) throughout the military service were significantly higher among smokers than in nonsmokers. An MBL level below the median proved to be a significant risk factor for the carriage of N. meningitidis (odds ratio [OR] = 1.9; 95% confidence interval [CI] 1.0-3.6) and beta-hemolytic streptococci (OR = 2.0; 95% CI 1.2-3.2) in the nonsmokers and a borderline significant risk factor for the carriage of S. pneumoniae (OR = 1.5; 95% CI 0.9-2.6), whereas low MBL levels producing MBL2 haplotypes (LXA/LXA, LXA/O, HYA/O, LYA/O, O/O) seemed to be associated with the carriage of N. meningitidis (OR = 1.8; 95% CI 1.0-3.4) and S. pneumoniae (OR = 1.6; 95% CI 0.9-2.7). Thus, MBL deficiency may predispose nonsmokers to oropharyngeal carriage of these bacteria. We hypothesize that the major factor contributing to elevated bacterial carriage in smokers might be increased bacterial adherence to epithelial cells, which obscures the effect of MBL.

[Influenza A(H1N1)v-patients treated in Oulu University hospital]

BACKGROUND

In Finland, the pandemic A(H1N1)v-influenza was experienced in late 2009.

MATERIAL AND METHODS

A(H1N1)v-patients hospitalized in Oulu University Hospital were evaluated.

RESULTS

Altogether, 159 A(H1N1)v-patients, including 37 children, were hospitalized. Their median age was 35. Eighteen (11 %) patients required admission to ICU; three of them died. As many as 62% of the patients suffered from radiologically confirmed pneumonia. The incidences of hospitalization, ICU care and death were 40,5, 4,6 and 0,8 per 100000, respectively.

CONCLUSIONS

Despite the low mortality rate, a rather high number of patients required hospitalization. Findings in chest radiography were common and prominent.

Glutathione-S-transferases in lung and sputum specimens, effects of smoking and COPD severity

BACKGROUND

Oxidative stress plays a potential role in the pathogenesis and progression of chronic obstructive pulmonary disease (COPD). Glutathione S-transferases (GSTs) detoxify toxic compounds in tobacco smoke via glutathione-dependent mechanisms. Little is known about the regulation and expression of GSTs in COPD lung and their presence in airway secretions.

METHODS

GST alpha, pi and mu were investigated by immunohistochemistry in 72 lung tissue specimens and by Western analysis in total lung homogenates and induced sputum supernatants from non-smokers, smokers and patients with variable stages of COPD severity.

RESULTS

GST alpha was expressed mainly in the airway epithelium. The percentage of GST alpha positive epithelial cells was lower in the central airways of patients with very severe (Stage IV) COPD compared to mild/moderate COPD (p = 0.02). GST alpha by Western analysis was higher in the total lung homogenates in mild/moderate COPD compared to cases of very severe disease (p < 0.001). GST pi was present in airway and alveolar epithelium as well as in alveolar macrophages. GST mu was expressed mainly in the epithelium. Both GST alpha and pi were detectable in sputum supernatants especially in patients with COPD.

CONCLUSION

This study indicates the presence of GST alpha and pi especially in the epithelium and sputum supernatants in mild/moderate COPD and low expression of GST alpha in the epithelium in cases of very severe COPD. The presence of GSTs in the airway secretions points to their potential protective role both as intracellular and extracellular mediators in human lung.

Risk factors for acute respiratory tract illness in military conscripts

BACKGROUND AND OBJECTIVE

Acute respiratory tract infections are the leading cause of missed service days among military conscripts. The aim of this study was to identify factors that possibly predicted and contributed to frequent respiratory tract infections among military conscripts.

METHODS

Data on episodes of respiratory illness were collected during the 180-day period of military service in Kajaani, Finland, between July 2004 and July 2005.

RESULTS

There were 518 military conscripts recruited, 124 of whom had a diagnosis of asthma. Conscripts with frequent (three or more) infections were more often atopic or suffered from allergic rhinitis or asthma. Overweight (BMI >/= 25 kg/m(2)) and previous respiratory tract infections were the two independent risk factors for frequent respiratory infections. Overall, 4.8% of those who had no risk factors, 10. 3% of those with one risk factor and 35.7% of those with two risk factors suffered from frequent respiratory infections (P for trend < 0.001).

CONCLUSIONS

Overweight (BMI >/= 25 kg/m(2)) and previous respiratory tract infections are risk factors for frequent respiratory tract infections in young men during military service.

Training improves physical fitness and decreases CRP also in asthmatic conscripts

To study the respiratory and physical health of young men, 224 asthmatic and 668 non-asthmatic military conscripts were recruited from the intake groups of July 2004 and January 2005 in Kajaani, Finland. Factors affecting respiratory health were elicited by a questionnaire at the beginning of the service, and results of high sensitive C-reactive protein (hsCRP) determination, peak expiratory flow (PEF), and 12-minute running test were collected at the beginning and the end of the service. Respiratory infections were diagnosed by a study physician. Upon entering military service, asthmatics had frequent exercise- and cold-related asthma symptoms (69.6% and 76.3%), and 48% of them had no medication for asthma. At the beginning, 25.8% of asthmatics and 19.1% of non-asthmatics had a poor result of less than 2,200 m (p = 0.05) in the 12-minute running test, and after 180 to 362 days of service, the corresponding percentages were 11.7% and 9.7% (p = 0.434). The levels of hsCRP, a marker of low-grade systemic inflammation, decreased significantly among both asthmatics, 1.5 (p = 0.001), and non-asthmatics, 1.6 mg/L (p < 0.001). Asthmatic men had 0.2 and non-asthmatics 0.1 respiratory infections per month (p < 0.001). In summary, asthmatic conscripts can enhance their physical fitness by training similarly to non-asthmatic ones. Their levels of hsCRP also decrease.

Does the oxidative stress in chronic obstructive pulmonary disease cause thioredoxin/peroxiredoxin oxidation?

The thioredoxin/peroxiredoxin system comprises a redox-regulated antioxidant family in human lung; its significance, regulation, or oxidation has not been evaluated in smoking-related lung diseases. Here, we present the expression of the thioredoxin/peroxiredoxin system in lung biopsies from normal lung (n = 14), smokers (n = 21), and patients with chronic obstructive pulmonary disease (COPD, n = 38), and assess the possible inactivation/oxidation of this system by nonreducing Western blotting, two-dimensional gel electrophoresis, and mass spectrometry. Our study shows that the thiol status of the Trx/Prx-system can be modulated in vitro, but it appears to have high resistance against the oxidative stress in COPD.

Acute Chlamydia pneumoniae infections in asthmatic and non-asthmatic military conscripts during a non-epidemic period

Chlamydia pneumoniae respiratory tract infections were studied in 512 male military conscripts (123 asthmatic and 389 non-asthmatic) taking part in 180-day service between July 2004 and July 2005 in Kajaani, Finland. Respiratory tract infections requiring a medical consultation were analysed prospectively. At baseline, at end of service, and during each episode of respiratory infection, blood samples were obtained for measurement of C. pneumoniae antibodies. Data concerning the clinical features of each infection episode were collected. Serological evidence of acute C. pneumoniae infection was found in 34 of the 512 conscripts with antibody data available, including 9.8% of the asthmatic subjects and 5.7% of the non-asthmatic subjects (p 0.111). A serological diagnosis could be made for 25 clinical episodes in 24 conscripts. The spectrum of respiratory tract infections included 13 episodes of mild upper respiratory tract infection and seven episodes of sinusitis, with five episodes involving asthma exacerbation. Two of three pneumonias were primary infections. Primary infections were diagnosed in five subjects, and re-infection/reactivation in 19 subjects, with the latter comprising 12 non-asthmatic subjects and seven asthmatic subjects (p 0.180). Prolonged infections were present in six asthmatic subjects and one non-asthmatic subject (p 0.001). A wide variety of respiratory tract infections, ranging from common cold to pneumonia, were associated with serologically confirmed C. pneumoniae infections. Infections were often mild, with common cold and sinusitis being the most common manifestations. Acute, rapidly resolved C. pneumoniae infections were equally common among asthmatic subjects and non-asthmatic subjects, whereas prolonged infections were more common among subjects with asthma.

Manganese superoxide dismutase is increased in the airways of smokers' lungs

Oxidant stress is a key mechanism for smoking-induced chronic obstructive pulmonary disease (COPD). Smoking has been shown to upregulate several antioxidant enzymes, with potential effects on the prevention of the disease and/or its progression. Superoxide dismutases (SOD)s are the only enzymes capable of consuming superoxide radicals. The purpose of the present study was to investigate SODs in the lungs of nonsmokers, smokers and COPD patients. Manganese superoxide dismutase (MnSOD), copper zinc SOD (CuZnSOD), and extracellular SOD (ECSOD), were investigated by immunohistochemistry in the airways of 13 nonsmokers, 20 smokers and 22 COPD patients with mild-to-moderate disease. Lung tissue homogenates of three nonsmokers and four smokers were used for Western blot and enzyme activity analysis. The expression of MnSOD was higher in the central bronchial epithelium of smokers with COPD and in the alveolar epithelium of smokers without or with COPD than innonsmokers. Lung MnSOD immunoreactivity, evaluated by Western blotting and specific activity, were 33% and 51% higher, respectively, in smokers than in nonsmokers. No major changes could be observed in lung CuZnSOD or ECSOD immunoreactivities. Manganese superoxide dismutase is elevated in the alveolar epithelium of cigarette smokers, probably due to the increased oxidant burden in smokers' lungs.

Chlamydia pneumoniae infection and inflammation in adults with asthma

BACKGROUND

Chlamydia pneumoniae infection and immune response to the C. pneumoniae heat shock protein 60 (CpHsp60) have been suggested to be associated with asthma.

OBJECTIVES

To study whether a slightly elevated C-reactive protein (CRP) level as a marker of low-grade systemic inflammation has a role in this association, we collected serum and sputum samples from 103 asthma patients with disease severity ranging from mild to moderate and from 30 healthy volunteers.

METHODS

IgA and IgG antibodies to C. pneumoniae elementary bodies (CpEB) and CpHsp60 were measured by enzyme immunoassay. Serum CRP levels were measured with a rapid two-site ultra-sensitive assay based on time-resolved immunofluorometry.

RESULTS

The asthma patients, especially those with moderate asthma, had higher serum IgA antibody levels to CpHsp60 than the healthy controls (test for trend, p = 0.05), whereas antibody levels to CpEB antigen did not differ between the study groups. CRP levels were higher in both asthma groups compared to the control group and moreover, the patients with moderate asthma had higher CRP levels than those with mild asthma (test for trend, p < 0.01). The subjects with a slightly elevated CRP level, defined as > or =1.8 mg/l, had higher CpEB IgA (p = 0.001), CpEB IgG (p = 0.008) and CpHsp60 IgA (p = 0.023) antibody levels in serum compared to the subjects with lower CRP levels.

CONCLUSIONS

Slightly elevated CRP levels as a marker of low-grade systemic inflammation may be associated with C. pneumoniae infection in asthma patients.

Diminished immunoreactivity of gamma-glutamylcysteine synthetase in the airways of smokers' lung

Glutathione (GSH) plays a major role in protecting the airways against oxidative stress. The rate-limiting enzyme in de novo GSH synthesis is gamma-glutamylcysteine synthetase (gamma-GCS), which is induced by acute exposure to GSH-depleting cytokines and oxidants, but downregulated by transforming growth factor beta and prolonged oxidant exposure, at least in vitro. Cell-specific expression or regulation of gamma-GCS may play an important role both in the defense against oxidants and in the pathogenesis of oxidant-associated airway diseases. In this study, the localizations of gamma-GCS heavy (gamma-GCS-HS) and light (gamma-GCS-LS) subunits were investigated by immunohistochemistry in 22 patients with chronic obstructive pulmonary disease (COPD), 20 smokers without COPD, and 13 lifelong nonsmokers. The ultrastructural distributions of both gamma-GCS subunits were assessed by immuno-electron microscopy. Both subunits were expressed most prominently in the large airways, and their ultrastructural localization was both cytoplasmic and along the plasma membrane. The expression of gamma-GCS-HS was stronger in the central bronchial epithelium than in the peripheral bronchioli (p = 0.020), or in alveolar macrophages (p = 0.008). The expression of gamma-GCS-HS in the central bronchial epithelium showed a tendency to be higher in nonsmokers compared with all smokers (p = 0.052). Alveolar macrophages of nonsmokers had higher levels of gamma-GCS-HS (p = 0.001) and gamma-GCS-LS (p = 0.001) than did smokers. The expression of gamma-GCS-HS in the central bronchial epithelium was more marked in nonsmokers than in patients with COPD (p = 0.015), the difference between smokers and patients with COPD was not significant. In conclusion, the heavy and light subunits of gamma-GCS are mainly expressed in the large airways. Their tendency to decrease in cigarette smokers may further predispose lung cells to ongoing oxidant stress, which contributes to the progression of lung injury.

Up-regulation of heme oxygenase-I in alveolar macrophages of newly diagnosed asthmatics

Exhaled carbon monoxide (CO), which has been found to be elevated in asthma, is generated primarily by heme oxygenase I (HO-I), an enzyme induced by oxidant stress and cytokines. The aim of this study was to assess the distribution and expression of HO-I in various human lung cells in acute and stable asthma. Normal lung tissue biopsies (from 6 non-smoking subjects operated on for a lung tumour) and macrophages from induced sputum (from 5 healthy controls, 5 untreated asthmatics, 7 stable treated asthmatics and 5 asthmatics recovering from exacerbation and being on systemic steroids) were investigated for HO-I by immunohistochemistry. The time response of HO-I induction was examined in cultured monocytes, which are known to maturate into monocyte-derived macrophages in culture. Lung biopsies showed prominent HO-I immunoreactivity only in alveolar macrophages. Macrophages in the induced sputum of healthy controls showed no HO-I immunoreactivity, with the exception of one case. Moderate or intense HO-I immunoreactivity could be observed in alveolar macrophages in 4/5 cases with recent asthma, and 2/7 with stable asthma, but in none ofthe patients treated with systemic corticosteroids for acute exacerbation. Experiments with cultured cells revealed that HO-I was induced by oxidants within the first 24 h, but the induction was reversed during the next 48 h. HO-I is mainly expressed in alveolar macrophages of human lung. Macrophages of induced sputum show prominent but transient HO-I immunoreactivity, in untreated asthmatics, but not in asthmatics treated with corticosteroids.

Seasonal variations in hospital treatment periods and deaths among adult asthmatics

The purpose of this study was to examine possible seasonal variations in relations between hospital treatment periods and in deaths (asthma-related and other) among adult asthmatics. Out of a total of 364,871 asthma-induced hospitalization periods (diagnosis No. 493, International Classification of Diseases) recorded in the hospital discharge register maintained by the National Research and Development Centre for Welfare and Health during 1972-1992, all of those applying to persons aged >24 yrs during 1987-1992 were analysed here. The discharge file was linked to the register of deaths on the basis of the patients' social security numbers in order to analyse all deaths among the same patients during 1987-1993. A total of 81,243 asthma-related treatment periods were analysed. The monthly variation in the number of such periods showed a peak in January (18.2% above the mean number of monthly deaths in the study period) and a trough in July (26.1% below the mean). Of the 7,622 hospitalized asthmatics who died during the period examined here, 1,274 died of obstructive pulmonary diseases, with asthma as the primary cause in 489 cases. The majority of the deaths were caused by cardiovascular diseases. Mortality was highest in January (+14.7%) and lowest in August (-12.3%). The similarity in the seasonal variation observed between the treatment periods and deaths recorded for adult asthmatics may be taken to indicate a genuine need for treatment.

Asthma-induced hospitalizations among conscripts in Finland in 1982-1992

The purpose was to examine changes in the numbers of asthma-related hospitalizations among conscripts and possible seasonal fluctuations. Data on treatment periods for asthma among men aged 18-22 years at military hospitals in 1982-1992 were collected from the national hospital discharge register. Monthly numbers of hospitalizations were calculated for each year separately, together with the frequency of such periods per 1000 conscripts. Results. A total of 4894 asthma-related hospitalizations were recorded in 1982-1992, the frequency per 1000 conscripts increasing from 8.5 in 1982 to 27.7 in 1992. Evident seasonal fluctuations were observed in 1982-1989, the peaks being recorded for February (14% above the annual average), July (26%) and November (51%). A change in these seasonal fluctuations was observed in 1990-1992, however. The frequency of asthma-induced hospitalizations among conscripts tripled between 1982 and 1992, evidently indicating a real increase in the number of occurrences. The hospitalization peaks are located at the beginning of military service, a point at which factors tending to aggravate asthma exercise a major impact.

Seasonal variation in childhood asthma hospitalisations in Finland, 1972-1992

All hospital treatment periods caused by asthma in children under 15 years in Finland during 1972-1992 were examined. The data were obtained from the Hospital Discharge Register, covering all hospitalisations in Finland. A total of 59,624 asthma related treatment periods were recorded. The monthly variation in hospitalisations peaked in May (35.6% above the trend) and in autumn and early winter (41.3% above the trend in October), whereas the monthly variations were low in late winter and in summer. The overall profile of seasonal variation was similar in both sexes, although admissions were lower for boys than for girls in winter and higher in autumn. The average monthly deviation was highest in the age group 0-4 years in May, 42.8% above the trend, and highest in the age group 5-9 years in October, 53.9% above the trend. Closer examination of the seasonal variation gives indirect information on possible trigger factors for acute asthma.

CONCLUSION

A clear seasonal variation could be observed in childhood asthma hospital admissions, together with age and sex-related differences in this seasonality. Preventive treatment for asthma should be used effectively in order to avoid acute attacks leading to hospitalisation in children who are allergic to birch pollen and also at times of viral respiratory infections.

Hospital admissions of asthmatics by age and sex

Asthma-related hospital admissions and the occurrence of new admissions were studied by age and sex in order to find the groups of asthmatics with high hospital admission rates. Data from the Finnish discharge register for 1972-92 were used to analyze the number of hospital admissions caused by asthma (defined in the International Classification of Diseases, 8th and 9th revisions, code 493) and occurrence of new asthma admissions between 1983 and 1992. A total of 192195 asthma-induced treatment periods were identified, 91223 for males and 100972 for females. Boys were admitted twice as often as girls at the age of 1 year (11.2 in comparison with 5.9 admissions per 1000 per year), whereas the admission rate was consistently higher among women 25-55 years of age. The highest asthma admission rate among the elderly was at age 73 for men (10.3 per 1000) and 75 for women (9.5 per 1000). Occurrences of new asthma admissions were most frequent at the age of 1 year (5.3 per 1000 for boys and 2.9 per 1000 for girls) and remained constant among those aged 50-80 years. Asthma is not only a disease of childhood and adolescence. The number of middle-aged and elderly asthmatics requiring hospitalization is markedly high.