Biomedical subjects

K Spiropoulos

Publications and source records attributed to K Spiropoulos.

At least 19 recordsLinked to original sources

PubMed2006

Carcinoid tumour behind bronchiectasis.

This report describes a female patient with bronchiectasis, presented to our department with recurrent hemoptysis. Bronchoscopy revealed nothing else but blood arising from the upper lobe bronchus. High resolution computing tomography of the lung (HRCT) revealed bronchiectasis of the upper lobe. A right upper lobectomy was performed. Behind bronchiectasis multiple nodular lesions, 5-10 mm were observed. Histological and immunohistochemical examination revealed findings consistent with peripheral typical bronchial carcinoids.

Bronchi↗

PubMed2006

Obstructive sleep apnoea syndrome and genes.

Obstructive sleep apnoea (OSA) is a complex disease entity strongly influenced by genetic factors, especially those that affect obesity and fat distribution, upper airway muscle tone, craniofacial morphology, ventilatory control and sleep, giving rise to the OSA phenotype. OSA can also be considered a metabolic syndrome which adversely affects multiple organ systems, especially the cardiovascular system and the brain. The most widely used clinical marker for the diagnosis of OSA is the apnoea-hypopnoea index, calculated by polysomnography. A percentage of 35 to 40% of its variance can be attributed to genetic factors. Therefore, the identification and elucidation of the genes implicated in the pathogenesis of OSA becomes a matter of extensive research and could lead to the development of therapeutic agents that can have a beneficial effect on the natural course of OSA.

Genetic Predisposition to Disease↗

PubMed2005

Accuracy of pulmonary function tests in predicted exercise capacity in COPD patients.

PURPOSE: The purpose of this study was to examine exercise tolerance in patients with COPD from measurements of resting pulmonary function parameters. METHODS: A total of 57 COPD patients were administered the pulmonary function test (PFT) and cardiopulmonary exercise test. The results were analyzed and essentially linear relationships emerged when each subject's VO2 peak was plotted against his individual PFT parameters. Those significant contributors were then introduced in a stepwise multiple regression analysis to determine the best predictor of the VO2 peak. RESULTS: Stepwise multiple regressions in variables revealed that peak oxygen consumption (VO2 peak) was predicted best by the following equation: VO2 peak=(maximum voluntary ventilation x 0.024)+(forced mid-expiratory flow x 0.47)+(body surface area x 0.988)-0.913 (r=0.90; r2=0.81 SE=0.29 L/min). CONCLUSION: We conclude that exercise capacity was predicted from measurements of resting pulmonary function parameters with excellent accuracy in the COPD patient.

Aged↗

PubMed2004

Effect of body position on PaO2 and PaCO2 during pregnancy.

BACKGROUND: The body position may have an effect on gas exchange though the magnitude of this effect has not been studied thoroughly during the three trimesters of pregnancy. OBJECTIVES: This study analyzes the effect of body position change on arterial oxygen tension (PaO2) and arterial carbon dioxide tension (PaCO2) in healthy pregnant women. METHODS: We examined 21 lung healthy pregnant women at the end of the first, second and third trimester of pregnancy. Blood was drawn from the radial artery first in the sitting and subsequently in the supine position. Peak expiratory flow rate was determined as well. RESULTS: No statistically significant difference was detected between the mean values of PaO2 in the supine and in the sitting position at the end of the first trimester. On the contrary, at the end of the second trimester the mean value of PaO2 in the supine position was 92.39 +/- 1.95 mm Hg, while in the sitting position the mean PaO2 was 96.56 +/- 1.83 mm Hg (p < 0.001). At the end of the third trimester the mean PaO2 in the supine position was 90.48 +/- 2.91 mm Hg while in the sitting position the mean PaO2 was 97.48 +/- 1.46 mm Hg (p < 0.001). CONCLUSIONS: According to our data we conclude that the statistically significant difference in PaO2 in the sitting and supine positions clearly shows that the position needs to be considered both when attempting to establish reference values and when evaluating gas tensions at the end of pregnancy.

Adult↗

PubMed2004

Erectile dysfunction in men with obstructive sleep apnea syndrome: a randomized study of the efficacy of sildenafil and continuous positive airway pressure.

The aim of this study was to compare the efficacy of sildenafil and continuous positive airway pressure (CPAP) in men with erectile dysfunction (ED) and obstructive sleep apnea syndrome (OSAS). In all, 30 men were randomly treated for 12 weeks either with sildenafil 100 mg before intercourse (15 men) or CPAP during night time sleep (15 men). Under sildenafil, 97/180 (53.9%) of attempted intercourses were successful compared to 33/138 (23.9%) under CPAP. The mean IIEF (erectile function domain score) was 12.9 and 9.3 after sildenafil and CPAP treatment, respectively (P=0.007), compared to 7.9 and 7 at baseline. In all, 53.3% of patients were satisfied with sildenafil and 20% with CPAP for ED treatment (P=0.058). Although sildenafil was superior to CPAP, comorbidities and OSAS per se possibly resulted in a lower effectiveness of sildenafil compared to that in the general population of ED men. While about half of the patients were not satisfied even with the more effective treatment, we conclude that a combination of the two therapeutic tools or a different therapeutic mode should be studied further.

Coitus↗

PubMed2004

Arterial oxygen tension during sleep in the third trimester of pregnancy.

BACKGROUND: Changes during pregnancy include reduced functional residual capacity (FRC) and residual volume (RV), increased alveolar difference for oxygen and, in the supine position, reduced cardiac output. In conjunction with sleep-related disturbances, these changes could lead to maternal oxygen desaturation during sleep. OBJECTIVES: Because of conflicting data from respiratory sleep studies in pregnancy, we performed complete polysomnography on 21 pregnant women at the 36th week of gestation and again postpartum. We also measured the partial pressure of oxygen in the arterial blood (PaO2) in the supine and sitting positions. METHODS: We tested 21 healthy pregnant women at the 36th week of gestation. Arterial samples were taken in the sitting position. Complete polysomnography was performed in all of the pregnant women. Before the polysomnography arterial samples were taken in the supine and sitting positions and then every 2 h until termination of the study. RESULTS: We did not find any correlation between SaO2/PaO2 levels and apnea, hypopnea or percent of rapid eye movement (REM) sleep. The frequency of apnea and hypopnea was significantly lower during pregnancy (5.81 +/- 2.1 apneas or hypopneas per hour of sleep) than postpartum (12.1 +/- 2.7 apneas or hypopneas per hour of sleep) (p < 0.001), which may be due to the raised level of progesterone. The PaO2 levels in the supine position were significantly lower than in the sitting position at 36 weeks of gestation (p < 0.001). No differences were found between PaO2 levels in the sitting and supine positions postpartum (p < 0.5). CONCLUSIONS: According to our results we conclude that 1) the frequency of apnea and hypopnea in pregnancy was significantly lower than postpartum, and 2) a significant difference in PaO2 levels in the sitting and supine positions was observed at 36 weeks of gestation.

Adult↗

PubMed2003

Normal pregnancy and oxygenation during sleep.

Pregnancy is associated with significant alterations in respiratory function. Changes during pregnancy include reduced functional residual capacity (FRC) and residual volume (RV), increased alveolar-arterial difference for oxygen (A-alphaPO2) and in the supine position, reduced cardiac output. In conjunction with sleep-related apneas or hypopneas, these could lead to maternal oxygen desaturation during sleep. Because of the conflicting data from sleep studies in late pregnancy, we performed complete polysomnography on 11 pregnant women at 36 weeks of gestation and again postpartum. We also measured the PaO2, every 2h. The frequency of apneas and hypopneas was significantly lower during pregnancy compared with that on the postpartum control night. PaO2 levels in the supine position, during sleep, were also significantly lower during pregnancy compared to the postpartum period. No correlation was observed between PaO2 levels and apneas or hypopneas or percent of REM sleep.

Adult↗

PubMed2003

Hematologic and biochemical laboratory parameters before and after a marathon race.

Marathon racing is a strenuous exercise that has a profound effect on many laboratory parameters. Participants in marathon races may require abstinence of exercise and the performance of laboratory assays several days after the event. The aim of this study was to evaluate the possible changes in blood cell count and biochemical parameters observed in participants in a marathon 3 days before and 3 days after and before and immediately after a cardiopulmonary exercise test. Incremental cycle ergometry up to maximal capacity was performed in 7 marathon runners, 3 days before and 3 days after the race. The % peak oxygen consumption (peak %VO(2)) achieved was statistically significantly lower after than before the race ( p = 0.02). No statistically significant differences were observed in cardiac frequency ( p = 0.148) or blood cell count ( p = 0.501). Also, the concentration of sodium, potassium, calcium, magnesium, lactate dehydrogenase (LDH), phosphocreatine kinase (CPK) and glucose, measured before and immediately after the pulmonary exercise test, did not differ significantly ( p < 0.5). A significant percentage of the laboratory results were outside the standard reference rates. According to our data, exercise performance, as expressed by peak %VO(2), continued to be decreased in marathon runners 3 days after the race. The blood cell count and biochemical parameters did not differ significantly but many marathon runners were outside the standard reference rates. Unfortunately, only 7 subjects were available for this study. Further studies with larger samples and with samples obtained at multiple times during and after exercise are needed to clarify the effects of long-distance running.

Blood Cell Count↗

PubMed2003

Can high resolution computed tomography predict lung function in patients with chronic obstructive pulmonary disease?

High-resolution computed tomography (HRCT) is a useful method for quantifying the extent of emphysema. Few reports have mentioned the relationships between HRCT scans and pulmonary function tests in chronic obstructive pulmonary disease (COPD). For diagnosis, COPD requires chronic airflow limitation and emphysema and/or chronic bronchitis. We examined 20 who were previous smokers with middle to moderate COPD. All were normocapnic with mean arterial oxygen pressure (PaO2) 77,52 +/- 16,789 mmHg. Forced spirometry, somatic plethysmography and cardiopulmonary exercise test were performed in each patient. HRCT was performed in both full inspiration and full expiration at three levels through the upper (at the aortic arch), lower (2 cm above the diaphragm), and middle lung (midpoint between upper and lower) levels. During expiration all pulmonary function parameters correlated with the HRCT grade in the middle right and left part of the lungs. The middle right part of the lung during expiration correlated statistically significant with MVV (r = -0.681, p = 0.001), forced vital capacity (FVC) (r = -0.477, p = 0.027), forced expiratory volumein 1 sec (FEV1) (r = -0.632, p = 0.002), resistance (r = 0.674, p = 0.001), residual volume (RV) (r = 0.733, p = 0.001), total lung capacity (TLC) (r = 0.696, p = 0.001), functional residual capacity (FRC) (r = 0.752, p = 0.001) and peak oxygen consumption during exercise (VO2) (r = -0.493, p = 0.023). The middle left part of the lung during expiration correlated statistically significant with MVV (r = -0.673, p = 0.001), FVC (r = -0.493, p = 0.027), FEV1 (r = -0.629, p = 0.003), resistance (r = 0.593,p = 0.005), RV (r = 0.601, p = 0.005), TLC (r = 0.546, p = 0.012), FRC (r = 0.594, p = 0.006) and peak VO2 (r = -0.525, p = 0.015). Forced expiratory volume in 1 sec (FEV1), which is a well-established measure of airflow obstruction, correlated with the HRCT grade (1) in the middle left part of the lung during inspiration (r = -0.468, p = 0.035) and during expiration (r = - 0.629, p = 0.003) (2) in the lower right lung during inspiration (r = -0.567, p = 0.007) and during expiration (r = -0.558, p = 0.008) (3) in the lower left lung during inspiration (r = -0.542, p = 0.011) and during expiration (r = -0.558, p = 0.008) (4) in the upper right lung during expiration (r = -0.469, p = 0.037) (5) in the upper left lung during expiration (r = -0.463, p = 0.035) and (6) in the middle right lung during expiration (r = -0.632, p = 0.002). According to our results HRCT was a valuable tool for evaluating the severity of COPD--especially the middle right and left part of the lungs, during expiration--and correlated well with pulmonary function tests.

Exercise Test↗

PubMed2003

Endothelin-1 levels in the pathophysiology of chronic obstructive pulmonary disease and bronchial asthma.

BACKGROUND: Endothelin-1 (ET-1) has been implicated in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD). The ET-1 levels are elevated during exacerbations of asthma and COPD in bronchoalveolar lavage, serum, and sputum and fails with treatment of the exacerbations. Hypoxemia stimulates ET-1 secretion. OBJECTIVE: The aim of this study was to examine the serum ET-1 levels in stable asthmatic and COPD patients. MATERIALS AND METHODS: We examined 48 COPD and 26 asthmatic patients and 34 normal subjects. We collected arterial samples to measure baseline ET-1 levels in all patients and in the control group, during the day. All the patients underwent formal polysomnography (EEG, ECG, airflow, respiratory muscle movement, oximeter) to detect the presence of nocturnal, nonapneic, and oxyhemoglobin desaturation. Twelve of the COPD patients and six of the asthmatic patients were disqualified because of inadequate sleep or sleep apnea syndrome. Nineteen of the COPD patients desaturated below a baseline sleep saturation of 90% for 5 min or more, reaching a nadir saturation of at least 85%. We collected arterial samples to measure ET-1 levels, 5 min after the first period of desaturation in each of the 19 desaturators COPD patients. None of the 20 asthmatic patients exhibited oxyhemoglobin desaturation during sleep. RESULTS: Baseline arterial ET-1 levels during the day were significantly higher in "desaturators" COPD patients (2.08+/-0.28 pg/ml) compared to "non-desaturators" COPD patients (1.38+/-0.16 pg/ml) (P<0.001) and to asthmatics (0.7+/-0.85 pg/ml) (P<0.001). ET-1 Levels in normal subjects were 1.221+/-0.02 pg/ml. In "desaturators" COPD patients ET-1 levels during the night, 5 min after the first oxyhemoglobin desaturation, were significantly higher (4.28+/-1.10 pg/ml) compared to those during the day (2.08+/-0.28 pg/ml) (P<0.001). A significant negative correlation was observed between ET-1 levels and degree of desaturation during the day (P=0.005, r=0.632) and during the night (P<0.001, r=0.930) in "desaturators" COPD patients. CONCLUSION: According to our results: (1) ET-1 levels were significantly higher in "desaturators" COPD patients than in "non-desaturators" COPD and in asthmatics; (2) ET-1 levels were significantly higher during the night than during the day in "desaturators" COPD patients; (3) the degree of desaturation correlated negatively with the ET-1 levels in "desaturators" COPD patients, both during daytime and nighttime. These findings are consistent with the hypothesis that ET-1 is implicated in the pathophysiology of asthma and COPD, especially if nocturnal, nonapneic, oxyhemoglobin desaturation exists.

Asthma↗

PubMed2001

Mechanisms of endothelin-1 elevation in chronic obstructive pulmonary disease patients with nocturnal oxyhemoglobin desaturation.

BACKGROUND: Nonapneic, oxyhemoglobin desaturation associated with sleep has been described in patients with chronic obstructive pulmonary disease (COPD). Hypoxemia stimulates endothelin-1 (ET-1) secretion. Once released, ET-1 can act locally to elicit sustained pulmonary artery vasoconstriction, bronchoconstriction and activation of alveolar macrophages. OBJECTIVE: The aim of this study was to examine a possible correlation between ET-1 levels and nocturnal, nonapneic, oxyhemoglobin desaturation during sleep, in patients with COPD. METHODS: We examined 48 COPD patients with formal polysomnography (EEG, ECG, airflow, respiratory muscle movement, oximeter) to detect the presence of nocturnal, nonapneic, oxyhemoglobin desaturation. Twelve of them were disqualified because of inadequate sleep or sleep apnea syndrome. Nineteen of them desaturated below a baseline sleep saturation of 90% for 5 min or more, reaching a nadir saturation of at least 85%. We collected arterial samples to measure ET-1 levels, after 5 min of the first period of desaturation, in each of the 19 patients. We also collected arterial samples in the morning, before the study, to measure baseline ET-1 levels in all patients. RESULTS: Baseline arterial ET-1 levels during the day were very significantly higher in 'desaturator' COPD patients (2.058 +/- 0.252 pg/ml) compared to 'non-desaturator' COPD patients (1.382 +/- 0.159 pg/ml; p < 0.001). Also in 'desaturator' COPD patients ET-1, levels during the night were significantly higher (4.297 +/- 1.107 pg/ml) compared to those during the day (p < or = 0.001) and a significant negative correlation was observed between ET-1 levels and degree of desaturation (p < 0.0001, r = 0.9305). CONCLUSIONS: According to our study we can conclude that (1) ET-1 levels are significantly higher in 'desaturator' COPD patients both during the day and during the night, and (2) ET-1 levels correlate negatively significant with the degree of the oxyhemoglobin desaturation. These findings are consistent with the hypothesis that ET-1 plays a very important role in the pathophysiological manifestations of COPD patients.

Aged↗

PubMed2001

Arterial endothelin-1 in interstitial lung disease patients with pulmonary hypertension.

The aim of this study was to evaluate the plasma arterial levels of Endothelin-1 (ET-1) and their relationship with hypoxia and pulmonary hypertension (PH) in patients with interstitial lung disease (ILD). Incremental cycle ergometry was performed in all patients up to maximal capacity. ET-1 levels during exercise (2.2 +/- 0.36 pgr/ml) were significantly higher than at rest (1.73 +/- 0.37 pgr/ml) (p < 0.001). ET-1 levels were also significantly correlated with arterial oxygen (PaO2) (r = -0.935, p < 0.001) and mean pulmonary arterial pressure (Ppa) (r = 0.657, p < 0.001). Increased pulmonary and peripheral blood levels of ET-1 have been described in, and postulated to contribute to, the pathophysiology of several lung diseases. In agreement with this, in the current study, the plasma arterial levels of ET-1 were also found to be significantly elevated in patients with various interstitial lung disorders during exercise, especially in those with severe hypoxia and pulmonary hypertension.

Endothelin-1↗

PubMed2000

Arterial and bronchoalveolar lavage fluid endothelin-1 concentration in asthma.

Endothelins are a family of peptide mediators that have a number of biological properties, including the ability to act as bronchoconstrictors and vasoconstrictors of isolated airways and vessels. Endothelin-1 (ET-1) is the more potent peptide compared with the other two peptides of the family. To examine a possible involvement of ET- 1 in the pathogenesis of asthma, we measured arterial ET-1 levels in 11 patients with atopic asthma during attack and during remission, and in 11 healthy control subjects. We also performed fiberoptic bonchoscopy and bronchoalveolar lavage (BAL) to measure ET-1 levels in the 11 asthmatic patients during remission, and in the 11 healthy control subjects. ET-1 concentrations in arterial blood and in BAL were measured by a radioimmunoassay method. Arterial ET-1 levels were very significantly higher in asthma attack (3.67 +/- 0.51 pg ml(-1)) and in asthma remission (2.65 +/- 10.62 pg ml(-1)) compared with those of the healthy controls (1.37 +/- 0.14 pg ml(-1)) (P < 0.001). Arterial ET-1 levels were also very significantly higher during asthma attack compared with those in asthma remission (P < 0.001). BAL ET-1 levels were significantly higher in asthma remission (0.73 +/- 0.53 pmol g(-1)) compared with those of the healthy controls (0.16 +/- 0.02 pmol g(-1)) (P < 0.05). No correlation was observed between arterial and BAL ET-1 levels, PaO2 and peak expiratory flow rate (PEFR). These data are consistent with the hypothesis that ET-1 contributes to the pathophysiology of asthma. However, it is likely that the true importance of this vasoconstrictor peptide will only be revealed by pharmacological studies with specific receptor antagonists.

Adolescent↗

PubMed2000

Chronic obstructive pulmonary disease management among primary healthcare physicians.

The aim of this study was to evaluate the dissemination of chronic obstructive pulmonary disease (COPD) management guidelines among primary healthcare physicians in Greece. One hundred and five of 120 (87.5% response rate) completed a questionnaire about COPD morbidity and management. One in eight patients examined by a primary care physician suffered from COPD. Forty-eight physicians treated their COPD patients according to the pulmonologist's recommendations and 69 according to COPD management guidelines. All the physicians encouraged and supported their COPD patients in stopping smoking, but continuous abstinence was low. The most commonly prescribed drugs were beta 2-agonist inhalers (14.8%), corticosteroid inhalers (13.47%), antibiotics (12.6%) and influenza vaccines (12.6%). The most commonly prescribed antibiotics were cephalosporins (33.72%), macrolides (27.71%) and amoxycillin plus clavulanic acid (25.3%). According to the present study, chronic obstructive pulmonary disease management among primary healthcare physicians was not in total accordance with current guidelines. Better dissemination of chronic obstructive pulmonary disease guidelines among specialists and primary healthcare physicians will hopefully make chronic obstructive pulmonary disease management in outpatients optimal.

Greece↗

PubMed1999

Non-invasive estimation of pulmonary arterial hypertension in chronic obstructive pulmonary disease.

The feasibility and reliability of the combination of several noninvasive methods using a multivariate method of analysis to predict pulmonary artery hypertension (PAH) is evaluated in 20 patients with chronic obstructive pulmonary disease. These methods comprised arterial blood gases (Pao2, Paco2), pulmonary functional parameters (FEV1), echo-Doppler parameters (tricuspid regurgitation jets, acceleration time on pulmonary valve), computed tomography measurements (transhilar distance, hilar thoracic index, and measurement of the descending branch of the right pulmonary artery to the lower lobe). A multiple stepwise regression analysis (including one Doppler parameter, two parameters of arterial blood gases, and one functional parameter) revealed a coefficient of determination (R2) equal to 0.954 for mean pulmonary artery pressure (MPAP) with a standard error of estimate (S.E.E.) of 5.25 mmHg. A stepwise regression analysis including computed tomography and radiographic parameters revealed an R2 equal to 0.970 for PAP with a S.E.E. of 4.26 mmHg. Logistical regression analysis classified correctly 80% of patients with PAH using noninvasive methods such as the diameter of the main pulmonary artery and the diameter of the left pulmonary arterial branch calculated by computed tomography. Not only the presence of PAH but also the level of MPAP can be estimated by the combination of multiple stepwise and logistical regression analyses.

Aged↗

PubMed1999

A new perspective in learning pattern generation for teaching neural networks.

This article deals with the Learning Patterns (LPs)' generation, a major aspect of Feed-Forward Artificial Neural Networks (FANNs)' learning process. Currently, more work is done to understand the mechanisms and improve the speed, learning accuracy, and implementation features of FANNs' teaching algorithms, though little is done towards the development of enhanced techniques that would extract experts' knowledge (from examples, rules, etc.) and obtain standardised LPs that would improve this learning process. A new approach in generating LPs is thereby introduced, that is used to train a new Medical Decision Support System (MDSS) based on FANNs, and its performance is analysed and compared with previous methods. It can handle incomplete data archives, individually boost any particular dataum special characteristics, and its application induces the FANNs to show better convergent facets. The efficiency of the resulting MDSS was thoroughly tested by pulmonologists and haematologists using medical data archives of a regional hospital.

Journal Article↗

PubMed1995

Orthopnea due to an aneurysm of the thoracic aorta.

Aneurysms of the thoracoic aorta may on rare occasions lead to shortness of breath by external compression of the tracheobronchial tree. We report the case of a patient who presented with orthopnea due to extensive compression of the trachea and the major airways by a large aneurysm of the ascending aorta.

Airway Obstruction↗

PubMed1993

Salivary immunoglobulin A production in chronic bronchitis patients given an orally administered bacterial extract.

The concentration of secretory immunoglobulin A (IgA) has been measured by the immunodiffusion method in 28 chronic bronchitis patients (group A) and in 11 comparable patients receiving corticosteroid therapy (0.5 mg/kg/day prednisone; group B). The measurements have been taken before and after oral administration of Broncho-Vaxom which is an extract of bacteria that usually cause infection of the respiratory tract. The mean concentration of secretory IgA in the saliva was increased by over 130% after the 10-day administration of the preparation to group A patients. This increase was statistically significant between the 12th and 40th day after the beginning of the treatment (p < 0.001). It fell to initial levels after 1 month in 15 patients (group A2) who received a single treatment course. In 13 patients (group A1) who received a second treatment course, beginning 1 month after termination of the first course, the high concentration of IgA in saliva persisted for at least 3 months. The saliva IgA was increased by over 35% in 11 chronic bronchitis patients (group B) who received corticosteroid therapy. In this group of patients the rise of IgA levels began later than in group A. The IgA fell to initial level after 1 month in 5 patients (group B2) who received a single treatment course. In 6 patients (group B1) who received a second treatment course the high concentration persisted longer. The saliva level of IgA in groups A and A1 was higher than in groups B and B1 (p < 0.05 and p < 0.001, respectively). No differences of IgA in the saliva between groups A2 and B2 were found during the study.

Adjuvants, Immunologic↗