Reliability of individual differences in distractor suppression driven by statistical learning.

A series of recent studies has demonstrated that attentional selection is modulated by statistical regularities, even when they concern task-irrelevant stimuli. Irrelevant distractors presented more frequently at one location interfere less with search than distractors presented elsewhere. To account for this finding, it has been proposed that through statistical learning, the frequent distractor location becomes suppressed relative to the other locations. Learned distractor suppression has mainly been studied at the group level, where individual differences are treated as unexplained error variance. Yet these individual differences may provide important mechanistic insights and could be predictive of cognitive and real-life outcomes. In the current study, we ask whether in an additional singleton task, the standard measures of attentional capture and learned suppression are reliable and stable at the level of the individual. In an online study, we assessed both the within- and between-session reliability of individual-level measures of attentional capture and learned suppression. We show that the measures of attentional capture, but not of distractor suppression, are moderately stable within the same session (i.e., split-half reliability). Test-retest reliability over a 2-month period was found to be moderate for attentional capture but weak or absent for suppression. RT-based measures proved to be superior to accuracy measures. While producing very robust findings at the group level, the predictive validity of these RT-based measures is still limited when it comes to individual-level performance. We discuss the implications for future research drawing on inter-individual variation in the attentional biases that result from statistical learning.

Comparison of Identification and Quantification of Polyphenolic Compounds in Skins and Seeds of Four Grape Varieties.

The aim of this study was to identify and quantify polyphenolic compounds in skin extracts from four Bulgarian grape varieties and compare them to those of seed extracts. The values of total phenolic contents, flavonoids, anthocyanins, procyanidins and an ascorbic acid in grape skin extracts were determined. The antioxidant capacities of skin extracts were evaluated using four different methods. The total phenolic content of skin extracts was 2-3 times lower than those of seed extracts. The significant difference between total parameter values of individual grape varieties were also found. According to the total phenolic content and antioxidant capacity of skin extracts, the different grape varieties were arranged in the following order: Marselan ≥ Pinot Noir ˃ Cabernet Sauvignon ˃ Tamyanka. The individual compounds in the grape skin extracts were determined using RP-HPLC and compared with those of the seed extracts. The determined composition of skin extracts was significantly different from the seed extracts' composition. Quantitative evaluation of the procyanidins and catechins in the skins was carried out. A correlation between phenolic contents, individual compounds and antioxidant capacity of different extracts was found. The studied grape extracts have a potential to be applied as natural antioxidants in the pharmaceutical and food industries.

Antimicrobial Potential, Antioxidant Activity, and Phenolic Content of Grape Seed Extracts from Four Grape Varieties.

The aim of this study was to evaluate the total phenolic content, composition, and antioxidant and antibacterial activities of four grape seed extracts (Cabernet Sauvignon, Marselan, Pinot Noir, and Tamyanka). The total phenolic content (TPC) and flavonoid, anthocyanin, procyanidin, ascorbic acid, DPPH, and ABTS antioxidant capacities of the grape seed extracts (GSEs) were determined. The extracts showed high TPC values (79.06-111.22 mg GAE/g). The individual components in the GSEs were determined using HPLC. High contents of catechin, epicatechin, and procyanidin B1 were found in the extracts. The antimicrobial activity of the obtained GSEs against Staphylococcus aureus, Bacillus cereus, and Escherichia coli was evaluated using the agar diffusion test and a test to determine the minimum inhibitory concentration (MIC). According to the effect on the growth of pathogens, the extracts were ranked in the following order: Pinot Noir > Marselan > Cabernet Sauvignon > Tamyanka. The tested bacteria showed high sensitivity to the extracts (MIC = 0.12-0.50 mg/mL). According to the MIC values, the bacteria were in the following order: S. aureus > B. cereus > E. coli. A correlation was found between the phenolic content of the GSEs and their antibacterial potential. The obtained results show that the studied GSEs have good potential as antioxidant and antimicrobial agents.

Characteristics of patients with severe asthma in primary and secondary care settings considered eligible for biological therapy - the Bulgarian RECOGNISE study.

INTRODUCTION: Asthma is a major non-communicable disease. It affects both children and adults, but is the most common chronic condition among the former. While inhaled controller drugs stabilize the disease in most asthma patients, there are a certain number of people who suffer from severe asthma, which requires treatment escalation. Oral corticosteroids are usually added, but they are associated with various side effects that may limit their application. The introduction of biologicals targeting inflammatory mediators has opened a new era of asthma treatment highlighting the importance of patient characterization.

Reactivation of tuberculosis in patient treated with the antifibrotic drug nintedanib.

The novel antifibrotic drugs for idiopathic pulmonary fibrosis give us an opportunity for change the course of the disease. Their usages are expected to rise with the widening of their indications. We report a case of a patient who complains of fatigue breathlessness on exertion, dry cough, and fever up to 38°C while on the antifibrotic drug nintedanib treatment. We proved the reactivation of latent tuberculosis (TB) by microbiology of bronchial lavage. The outpatient died from massive hemoptysis. To our knowledge, we present the first case in the world for reactivation of TB in a patient on treatment with nintedanib. We suggest closer follow-up for patients with a history of TB or living in countries with higher TB prevalence during treatment with antifibrotic drugs.

Assessment of extrafine beclomethasone/formoterol for the treatment of chronic obstructive pulmonary disease: A non-interventional study in a Bulgarian population.

BACKGROUND: The beneficial effects of application of a fixed dose beclomethasone dipropionate (BDP) and formoterol fumarate (F) for the treatment of severe chronic obstructive disease (COPD) has been amply proven in well controlled clinical trials. Whether this also holds for real-world conditions and in such a heterogeneous patient population as is encountered in Bulgaria remained to be investigated. METHODS: In an observational, non-interventional study, 441 Bulgarian patients with severe COPD who were enrolled at 36 sites across the country received extrafine BDP/FF-combination therapy using the NEXThaler® DPI or the Foster® pMDI over a period of 16 weeks. At visits at the beginning, after 4 weeks and at the end of the study, alterations in lung function parameters FEV1 and FVC, disease symptoms, changes in CAT score, and patient distribution in GOLD 2017 categories A through D were assessed. RESULTS: A large share of the Bulgarian patients with severe COPD suffered from serious comorbidities, received additional medication, and about 2/3 were former or current smokers. Extrafine BDP/FF caused an increase in mean FEV1, FVC, a decrease of health impact as assessed by the CAT score, and a considerable shift of the share of category C and D patients towards A and B. In addition, the percentage of patients that were free of symptoms impacting everyday life such as fatigue and shortness of breath at rest increased throughout the study. A comparison of both application devices indicated that the NEXThaler® was superior in terms of lung functional aspects, as these parameters displayed a constant improvement over the observation period, whereas they plateaued at week 4 when using the pMDI. CONCLUSIONS: The therapeutic benefits of extrafine BDP/FF known from clinical trials could also be observed in a real-world setting, even in such a heterogenous patient population as the Bulgarian. The NEXThaler® appeared to be highly efficient in this setting, opening a new choice for the lung specialist and the patient to select the one device considered most suitable and practical.

Simultaneous enumeration of CD34+ and CD45+ cells using EasyCounter image cytometer.

Accurate counting of CD34-positive cells is important for successful hematopoietic stem cell transplantation that is applied to various diseases. The aim of this study was simultaneous counting of viable CD34+ (vCD34+) and CD45+ (vCD45+) cells in apheresis samples by automatic immunofluorescence counter - EasyCounter BC. CD34+ and CD45+ cells were counted using two conjugates anti-CD34 antibody - dR110 and anti-CD45 antibody - ATTO620, respectively. The conjugates were prepared by carbodiimide method. Dead nuclear cells were counted by using monomethine cyanine dye PO-TEDM 1. The linearity and reproducibility of EasyCounter BC for CD34+ cell counting were determined (R2 = 0.99; CV values for vCD34+ cells were 6.8 ÷ 8.5% and for vCD45+ cells 4.1 ÷ 7.2%). The obtained results by EasyCounter BC were compared with those by other two standard methods - flow cytometry (Guava easyCyte 8HT) and fluorescence microscopic method (Olympus BX51) with the same conjugates. Passing-Bablok regression was performed to determine the relationship between the results of the three methods, analyzing 43 apheresis samples. Correlation coefficients for vCD45+ and vCD34+ between EasyCounter BC and Olympus microscope were 0.987 and 0.982, respectively (P < 0.0001). Better results were obtained between EasyCounter BC and flow cytometer Guava, 0.998 for vCD45+ and 0.998 for vCD34+ (P < 0.0001).

The relationship of bovine milk somatic cell count to neutrophil level in samples of cow's milk assessed by an automatic cell counter.

This research communication describes the application of a fluorescent automatic cell counter Lactoscan SCC for simultaneous determination of somatic cell count and neutrophils in bovine milk. The obtained results were compared with results obtained by a flow cytometer and a light microscope. The Pearson correlations between the methods were calculated. A comparison between the main characteristics of the three kinds of analysis was made - the assay duration and the intra-assay precision. A relation between the SCC and neutrophil cells was observed in 55 milk samples. The obtained results confirm that the simultaneous determination of SCC and neutrophil analysis are necessary and support the early diagnosis of mastitis, the timely treatment of the animal and the avoidance of major economic losses.

Simultaneous determination of ochratoxin A and enterotoxin A in milk by magnetic nanoparticles based fluorescent immunoassay.

Ochratoxin A (OTA) and staphylococcus enterotoxin A (SEA) are highly toxic contaminants and have induced human health problems. They commonly occur in milk and milk products. A competitive fluorescent immunoassay was developed for rapid and simultaneous determination of these toxins in milk samples. The procedure was based on the competitive immunoreactions between antigens in sample and antigen-fluorescent dye conjugates with immobilised antibodies on magnetic nanoparticles (MNPs). Each monoclonal antibody specifically recognises its corresponding toxin (antigen), and there is no cross-reactivity in the assay. First, monoclonal antibodies against OTA and SEA were produced. The activity of the obtained antibodies was determined by fluorescent-linked immunosorbent assay. Then, the monoclonal antibodies were immobilised on MNPs. The amounts of immobilised anti-OTA antibody and anti-SEA antibody were determined to be 20 and 22 µg mL-1, respectively. The antigen-fluorescent dye conjugates OTA-OVA-ATTO620 and SEA-FITC were prepared. The optimal amount of immobilised antibodies for competitive immunoassay was determined. It was found that the linear range of OTA in buffer was larger (0.001-100 ng mL-1) than the linear range of SEA (0.001-20 ng mL-1). The results for simultaneous determination of OTA and SEA in sixfold diluted milk were almost the same in buffer; the linear range for OTA was from 0.005  to 100 ng mL-1 and for SEA from 0.005  to 20 ng mL-1. The detection limit for both OTA and SEA in milk was 0.004 ng mL-1. The developed method took half the time of the individual assays (20 min). The assay was evaluated using spiked milk samples. The influences of somatic cell count, fat, pH and protein concentration in milk on immunoassay were studied. In summary, this developed immunoassay could provide an effective and rapid approach for detecting multi-toxins in milk samples.

Distractor suppression leads to reduced flanker interference.

Recent studies using the additional singleton paradigm have shown that regularities in distractor locations can cause biases in the spatial priority map, such that attentional capture by salient singletons is reduced for locations that are likely to contain distractors. It has been suggested that this type of suppression is proactive (i.e., occurring before display onset). The current study replicated the original findings using an online version of the task. To further assess the suppression of high-probability locations, we employed a congruence manipulation similar to the traditional flanker effect, where distractors could be either congruent or incongruent with the response to the target. Experiment 1 shows that through statistical learning distractor suppression reduces the interference from incongruent distractors, as participants made less errors in high-probability versus low-probability conditions. In Experiment 2, participants were forced to search for a specific target feature (the so-called feature-search mode), which is assumed to allow participants to ignore distractors in a top-down manner. Yet even when this "top-down" search mode was employed, there was still a congruence effect when the distractor singleton was presented at the low-probability but not at the high-probability location. The absence, but not reversal, of a congruence effect at the high-probability location also further indicates that this distractor suppression mechanism is proactive. The results indicate that regardless of the search mode used, there is suppression of the high-probability location indicating that this location competes less for attention within the spatial priority map than all other locations.

CD34+ stem cell counting using labeled immobilized anti-CD34 antibody onto magnetic nanoparticles and EasyCounter BC image cytometer.

The ability of immobilized conjugate anti-CD34+ monoclonal antibody-dR110 and free conjugate anti-CD45+ monoclonal antibody-ATTO620 to precisely enumerate CD34+ stem cells and CD45+ cells in apheresis samples were evaluated. The conjugates anti-CD34+ antibody-dR110 and anti-CD45+- antibody-ATTO620 were prepared. Functionalized magnetic nanoparticles (MNPs) were synthesized. The anti-CD34+ antibody-dR110 conjugate was immobilized on the modified MNPs using a carbodiimide method. The stem cell count in thawed apheresis samples was determined using the free and the immobilized conjugate anti-CD34+ antibody-dR110 on MNPs and an image cell counter EasyCounter BC. A higher stem cell count and more accurate results were obtained with the immobilized conjugate, because a separation and concentration of the stem cells bound to antibody-dR110 on MNPs by external magnet were performed. Coefficients of variation of CD34+ cell count in apheresis samples, determined by EasyCounter BC, were ranged from 5.5 to 6.9% and those of CD45+ cell count from 3.8 to 4.7%. The viability of CD34+ cells was high from 98.5 to 99.6%. It was found that correlation coefficient between the flow cytometer and automatic cell counter, using free anti-CD34+ antibody-dR110 was 0.94, and when using immobilized anti-CD34+antibody-dR110 on MNPs, the correlation coefficient was 0.97.

Protocol for the EARCO Registry: a pan-European observational study in patients with α1-antitrypsin deficiency.

RATIONALE AND OBJECTIVES: Alpha-1 antitrypsin deficiency (AATD) is a genetic condition that leads to an increased risk of emphysema and liver disease. Despite extensive investigation, there remain unanswered questions concerning the natural history, pathophysiology, genetics and the prognosis of the lung disease in association with AATD. The European Alpha-1 Clinical Research Collaboration (EARCO) is designed to bring together researchers from European countries and to create a standardised database for the follow-up of patients with AATD. STUDY DESIGN AND POPULATION: The EARCO Registry is a non-interventional, multicentre, pan-European, longitudinal observational cohort study enrolling patients with AATD. Data will be collected prospectively without interference/modification of patient's management by the study team. The major inclusion criterion is diagnosed severe AATD, defined by an AAT serum level <11 µM (50 mg·dL-1) and/or a proteinase inhibitor genotype ZZ, SZ or compound heterozygotes or homozygotes of other rare deficient variants. Assessments at baseline and during the yearly follow-up visits include lung function testing (spirometry, body plethysmography and diffusing capacity of the lung), exercise capacity, blood tests and questionnaires (symptoms, quality of life and physical activity). To ensure correct data collection, there will be designated investigator staff to document the data in the case report form. All data will be reviewed by the EARCO database manager. SUMMARY: The EARCO Registry aims to understand the natural history and prognosis of AATD better with the goal to create and validate prognostic tools to support medical decision-making.

Free-viewing multi-stimulus eye tracking task to index attention bias for alcohol versus soda cues: Satisfactory reliability and criterion validity.

Cognitive -motivational models point to attention bias (AB) as an important factor in the persistence of problematic drinking behavior. Unfortunately, the measures that have been used to examine AB in addiction typically showed poor psychometric properties. To bring research on AB a critical step further it would be crucial to develop tasks with acceptable reliability and construct validity. Recently, Lazarov and colleagues (2016) developed a multi-stimulus free-viewing task (participants were free to look at any part of the screen and there was no secondary task involved) that showed excellent psychometric properties in the context of social anxiety as well as depression. We, therefore, adapted this task and examined its psychometric quality within the context of alcohol use. Participants with varying levels of alcohol use (N = 100) were presented with 54 matrices each containing 8 alcoholic and 8 non-alcoholic drinks. Each matrix was presented for 6 s. First fixation (100 ms) location and latency and total dwell time were assessed for alcohol and soda pictures. Assessment of AB, craving, and alcohol use (problems) was repeated after 3-8 days. Specifically, the dwell-time based AB-measure showed excellent internal reliability and considerable stability. Supporting the validity of the current AB-measures, it was found that participants with higher scores on craving and alcohol problems (i) dwelt longer on alcohol stimuli, and (ii) more often showed a first fixation on alcohol, whereas (iii) stronger craving was associated with shorter latency of first alcohol fixations. The AB-measure showed promising psychometric properties. Thus, this free-viewing eye-tracking task seems a welcome new tool for being used in future research on AB in addiction.

The effect of pupil size and peripheral brightness on detection and discrimination performance.

It is easier to read dark text on a bright background (positive polarity) than to read bright text on a dark background (negative polarity). This positive-polarity advantage is often linked to pupil size: A bright background induces small pupils, which in turn increases visual acuity. Here we report that pupil size, when manipulated through peripheral brightness, has qualitatively different effects on discrimination of fine stimuli in central vision and detection of faint stimuli in peripheral vision. Small pupils are associated with improved discrimination performance, consistent with the positive-polarity advantage, but only for very small stimuli that are at the threshold of visual acuity. In contrast, large pupils are associated with improved detection performance. These results are likely due to two pupil-size related factors: Small pupils increase visual acuity, which improves discrimination of fine stimuli; and large pupils increase light influx, which improves detection of faint stimuli. Light scatter is likely also a contributing factor: When a display is bright, light scatter creates a diffuse veil of retinal illumination that reduces perceived image contrast, thus impairing detection performance. We further found that pupil size was larger during the detection task than during the discrimination task, even though both tasks were equally difficult and similar in visual input; this suggests that the pupil may automatically assume an optimal size for the current task. Our results may explain why pupils dilate in response to arousal: This may reflect an increased emphasis on detection of unpredictable danger, which is crucially important in many situations that are characterized by high levels of arousal. Finally, we discuss the implications of our results for the ergonomics of display design.

Pharmacoeconomics of Bronchial Asthma.

INTRODUCTION: Pharmacoeconomics (PE) treats the problems of pharmacotherapy policy, drug marketing and reimbursement and clinical trials. It guides policy makers for effective health resources utilization and determines the profitability of the new drugs on the basis of their price, efficacy and benefits for society. Types of health costs and pharmacoeconomic analyses: In the current review the main types of health costs are discussed. The main PE analyses with their advantages and disadvantages are presented. Pharmacoeconomic of bronchial asthma: The main aspects of PE of bronchial asthma are available in the current review. The costs of health services (direct and indirect), the educational programs and asthma medications in different countries are discussed. Recently published data showed correlation between asthma cost and disease severity, control, social status and therapy adherence. CONCLUSION: PE analyses provide the benefit of making cost consistent decisions in the field of asthma care. This review adds more data on the cost of current asthma treatment worldwide and in Bulgaria.

Autofluorescence and White Light Bronchoscopy in the Diagnosis of Endobronchial Malignant Lesions.

BACKGROUND: Autofluorescence bronchoscopy (AFB) allows a more sensitive approach to the diagnosis of premalignant and malignant endobronchial lesions than white light bronchoscopy (WLB) can do. AIM: To assess the autofluorescence bronchoscopy and white light bronchoscopy in diagnosing malignant endobronchial lesions. MATERIALS AND METHODS: The design of the study is a retrospective case-control study. Thirty-two parameters were entered into an Excel file and analysed with SPSS v. 21 for Mac book Pro. Endoscopy findings were graded in 4 options and morphological results - in 9 options according to WHO classification. The results are presented using McNemar's test and sensitivity, specificity and positive and negative predictive values as well. RESULTS: Three hundred and three patients were included in the study. Lung cancer was found in 38.3% of the patients using histology and in 35.6% - using cytology. McNemar's test for AFB finding for suspected and malignant lesions OR was 8.333 (95% CI 3.571-23.784) while for WLB OR was 0.128 (95% CI 0.045-0.299). For cytological results OR was 3.800 (95% CI 2.123-7.227) and 3.471 (95% CI 1.996-6.351), respectively. P value was <0.0001 for all tests. Sensitivity for AFB and WLB was 94.83% but specificity was 52.83% and 55.66% if histology was used. For cytology these numbers were respectively 86.11% and 84.26% for sensitivity, and 63.69% and 62.42% for specificity. CONCLUSION: AFB has an advantage over WLB in diagnosing endobronchial malignant lesions. Biopsying suspicious, not only visible malignant lesions, increased diagnostic sensitivity.

Diagnosis and Treatment of Three Cases of Bronchial Carcinoma In Situ.

As part of a retrospective study on bronchoscopies performed at the Clinic of Pneumonology and Phthisiatry of the University Hospital - Pleven by autofluorescence bronchoscopy we found 3 cases diagnosed with carcinoma in situ. They were treated in different ways - endobronchial electrocoagulation, extraction by forceps biopsy and open surgery, but the result was the same - clinical healing. The paper presents the three clinical cases and the analysis of the treatment.

Real-life evaluation of COPD treatment in a Bulgarian population: a 1-year prospective, observational, noninterventional study.

Introduction: This was the first study designed to prospectively evaluate treatment patterns in chronic obstructive pulmonary disease (COPD) and the degree of adherence with the Global Initiative for Chronic Obstructive Lung Disease (GOLD) strategy recommendations in routine clinical practice in Bulgaria. Methods: The study was conducted in an outpatient setting and enrolled patients of both genders, aged >40 years, who were diagnosed with COPD (as per GOLD 2013). Evaluations were performed at baseline and at 6- and 12-month visits. Results: Of the 811 enrolled patients, 719 were assessed and completed the 12-month observation period. Overall, a substantial number of patients experienced moderate airflow limitation (~49% patients, GOLD 2 as per GOLD 2013; mean postbronchodilator forced expiratory volume in 1 second value was ~50% of the predicted value), belonged to GOLD group D (~51% patients), and had COPD assessment test score ≥10 or modified Medical Research Council score ≥2 (~79% patients), and ≤1 exacerbation in the past 1 year (~80% patients). Short-acting ß2-agonists (~63% patients), inhaled corticosteroids/long-acting ß2-agonist fixed-dose combination (~62% patients), and long-acting muscarinic antagonists (~59% patients) were the most frequently used medications at all visits, regardless of severity. High levels of deviation from GOLD recommendations were observed in GOLD groups A and B patients. The deviation comprised high use of inhaled corticosteroid-containing regimens in ~45% and 63% of patients in GOLD groups A and B, respectively. Only 25 (3%) of the 796 patients reported at least one adverse event. Conclusion: The routine clinical practice for COPD in Bulgaria deviates from the GOLD recommendations largely in patients at a low risk (GOLD groups A and B), while the deviation was lesser in those at a higher risk (GOLD groups C and D).

Stability of Frequent Exacerbator Phenotype in Patients with Chronic Obstructive Pulmonary Disease.

BACKGROUND: At present, there is little information in Bulgaria regarding the rate and stability of frequent-exacerbation phenotype in COPD patients. AIM: To study the rate and stability of frequent-exacerbation phenotype in COPD patients. MATERIALS AND METHODS: We followed up 465 COPD patients for exacerbations over a 3-year period. Exacerbations were defined as events that resulted in treatment with antibiotics and/or corticosteroids (moderate), or that led to hospitalization (severe). RESULT: Approximately 10% of the patients had two or more exacerbations per year (frequent-exacerbation phenotype), and this structure stayed stable over the study period. The exacerbation rate in the first year of follow up was 0.33 per stage I COPD patients (according to GOLD stages), 0.49 per stage II COPD patients; 0.69 - for stage III, and 1.06 for stage IV COPD patients. The frequent-exacerbation rate increased from stage I to stage IV by 4.35%, 9.17%, 10.79%, and 20.97%, respectively. A history of previous year exacerbations increased the risk of new exacerbations: with a history of one exacerbation - OR 2.1820 (95% CI: 1.4018 to 3.3965, p = 0.0005), and with a history of two exacerbations - OR 4.6460 (95% CI: 2.3286 to 9.2696; p < 0.0001). The frequent-exacerbation phenotype appeared to be unstable over the study period - up to 33% from those patients stayed in the phenotype for the next year. CONCLUSIONS: The exacerbation frequency and the rate of frequent-exacerbation phenotype increases with COPD progression. History of exacerbations in the previous year is a significant risk factor for exacerbations of COPD. The frequent-exacerbation phenotype appeared to be unstable over the study period. The pheno-type of non-exacerbators was more likely to remain stable over time.

Impact of Air Pollution and Outdoor Temperature on the Rate of Chronic Obstructive Pulmonary Disease Exacerbations.

BACKGROUND: Environmental pollution can be one of the main risk factors for acute exacerbations of chronic obstructive pulmonary disease (COPD). AIM: To study the relationship between air pollution, outdoor temperature and exacerbations of COPD. MATERIALS AND METHODS: COPD patients (n=1432) were followed up for one year. The levels of particulate matter up to 10 µm (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2) and outside temperatures were collected from the Environmental Agency database. RESULTS: A total of 309 acute COPD exacerbations (AECOPD) were recorded in the analysis. The daily mean concentrations of PM10 were found to correlate significantly with the daily mean concentrations of NO2 and SO2 (ρ 0.34 and ρ 0.49, respectively; p=0.0001). The negative correlations between the daily mean temperature and the daily mean levels of PM10, NO2 and SO2 were also significant (ρ -0.44, ρ -0.11, and ρ -0.37, respectively; p=0.0001). The daily number of AECOPD correlated with the mean levels of PM10 in the previous six days (ρ 0.14; p=0.02) and the lower outdoor temperature (ρ -0.2; p=0.001). The negative correlation between the daily number of AECOPD and the mean daily temperature was stronger in days with levels of PM10 above 50 µg/m3 (ρ -0.3 p=0.02 vs. ρ -0.18 p= 0.01). CONCLUSION: Lower daily mean temperatures were associated with the levels of air pollutants. The level of PM10 correlated with the levels of the other air pollutants. The daily number of AECOPD was found to correlate weakly, but signifi cantly with the mean level of PM10 in the previous six days.