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Biomedical subjects

Konstantinos Gourgoulianis

Publications and source records attributed to Konstantinos Gourgoulianis.

At least 19 recordsLinked to original sources
PubMed2006

A brief exposure to moderate passive smoke increases metabolism and thyroid hormone secretion.

CONTEXT: Active smoking influences normal metabolic status and thyroid function. OBJECTIVE: The objective was to assess experimentally the effects of 1 h of moderate passive smoking in a controlled simulated bar/restaurant environment on the metabolism and thyroid hormone levels in healthy nonsmokers. PARTICIPANTS: Eighteen (nine females, nine males) healthy individuals (mean +/- sd: age, 25.3 +/- 3.1 yr; height, 174.0 +/- 10.1 cm; weight, 65.2 +/- 13.7 kg) participated in the study. DESIGN: In repeated-measures randomized blocks, participants visited the laboratory on 2 consecutive days. In the experimental condition, they were exposed to 1 h of moderate passive smoking at a carbon monoxide concentration of 23 +/- 1 ppm in an environmental chamber, whereas in the control condition participants remained in the same chamber for 1 h breathing normal atmospheric air. MAIN OUTCOME MEASURES: In both conditions, cotinine serum and urine levels, resting energy expenditure (REE), as well as concentration of T3, free T4, and TSH were assessed before participants entered the chamber and immediately after their exit. Heart rate and blood pressure were tested in 10-min intervals during all REE assessments. RESULTS: The mean +/- sd difference of serum and urine cotinine levels (-0.27 +/- 3.94 vs. 14.01 +/- 6.54 and 0.05 +/- 2.07 vs. 7.23 +/- 3.75, respectively), REE (6.73 +/- 98.06 vs. 80.58 +/- 120.91) as well as T3 and free T4 (0.05 +/- 0.11 vs. 0.13 +/- 0.12 and 0.02 +/- 0.15 vs. 0.22 +/- 0.20) were increased in the experimental compared with the control condition at baseline and follow-up (P < 0.05). No statistically significant variation was observed in the mean difference of the remaining parameters (P > 0.05). Serum and urine cotinine values were linearly associated with REE (P < 0.05). CONCLUSION: One hour of passive smoking at bar/restaurant levels is accompanied by significant increases in metabolism and thyroid hormone levels.

Adult↗
PubMed2006

Combination of staphylococcal chromosome cassette SCCmec type V and Panton-Valentine leukocidin genes in a methicillin-resistant Staphylococcus aureus that caused necrotizing pneumonia in Greece.

We describe a case of necrotizing pneumonia in Greece caused by a community-acquired methicillin-resistant Staphylococcus aureus (MRSA) producing Panton-Valentine leukocidin (PVL) carrying the staphylococcal chromosome cassette mec (SCCmec) type V. The pulse field gel electrophoresis (PFGE) pattern of this strain differed significantly from the PVL-positive multi-locus sequence typing (MLST)-80 clone of MRSA, which predominates in Greece and in Europe. Further analysis of this strain revealed that it belonged to the agr1 allele type, and its resistance to tobramycin, gentamicin, and kanamycin was associated to the presence of aac-(6')-Ie+aph(2') gene. This is the 1st report that documents the emergence of CA-MRSA with PVL genes in combination with the SCCmec type V in Europe.

Adult↗
PubMed2006

Greek medical students' career choices indicate strong tendency towards specialization and training abroad.

The aim of the study was to investigate the career choices, location preferences and criteria among medical students in Greece. We applied a questionnaire-based analysis using a sample of 591 students of four out of seven Greek Medical Schools. The sample included students of all academic years. The vast majority of students wish to specialize (97.6%), while general practice gathered a very low percentage (1.7%). The scientific challenge (61.4%) and interaction with patients (60.6%) seem to be the major influencing factors for most of the students' specialty preferences, whilst less common variables influencing career choice are the high demand/supply ratio for certain health services (40.4%), the income potential (31.4%), the active tempo (26.2%) and prestige (15%). 70.3% of those asked consider the possibility of specializing abroad. The low concern of Greek medical students for general practice reveals today's drastic deficiency in Greek primary health care. Such a situation will escalate, unless targeted strategies to produce more general practitioners are adopted. Furthermore, the results reflect a lower education and organizing level urging students to specialize abroad. The National Health System (NHS) should be reformed towards a rationalistic distribution of the medical specialties and medical workforce.

Adult↗
PubMed2006

mu-Opioid influence on transmesothelial resistance of isolated sheep pleura and parietal pericardium.

The effect of morphine (mu-opioid receptor agonist) on the transmesothelial resistance (R(TM)) of sheep's pleura and parietal pericardium was studied using the Ussing chamber technique. Basal transmesothelial resistance of parietal pleura was found to be 19.57+/-0.32 Omega cm2 and of visceral pleura was found to be 19.41+/-0.31 Omega cm2, whereas that of parietal pericardium was found to be 22.83+/-0.4 Omega cm2. Immediately after the addition of morphine (10(-9) M) both apically and basolaterally on the parietal pleura and parietal pericardium, these values were significantly increased (P<0.05). On the contrary, addition of morphine (10(-9) M) resulted in a rapid increase, only when placed basolaterally on the visceral pleura (P<0.05). In conclusion, our findings suggest that morphine, probably through mu-opioid stimulation, increases in vitro the transmesothelial resistance of the parietal pleura, of the visceral pleura when added basolaterally and of the parietal pericardium.

Analgesics, Opioid↗
PubMed2006

Association between primary nocturnal enuresis and habitual snoring in children.

OBJECTIVES: Nocturnal enuresis has been associated with obstructive sleep-disordered breathing mostly in hospital-referred adults and children. To investigate whether primary nocturnal enuresis is significantly associated with habitual snoring in the general pediatric population irrespective of subjects' age and sex, we studied children attending six randomly selected schools in a city in central Greece. METHODS: A questionnaire regarding the symptoms of sleep-disordered breathing and the presence of nocturnal enuresis (bedwetting for at least one night per week) was answered by the children's parents. RESULTS: A total of 1821 children (age 5 to 14 years; 896 girls) were included in the study. Of these, 135 (7.4%) were snoring more frequently than three nights per week (habitual snorers). The habitual snorers had a history of primary nocturnal enuresis more often than did nonhabitual snorers (7.4% versus 2%; odds ratio 4.00, 95% confidence interval 1.93 to 8.32). The association of primary nocturnal enuresis with habitual snoring remained significant after adjustment for age and sex (odds ratio 3.54, 95% confidence interval 1.68 to 7.44). CONCLUSIONS: In a community sample of children, those with habitual snoring more often had primary nocturnal enuresis than did those without snoring.

Adolescent↗
PubMed2006

Overnight change in brain natriuretic peptide levels in children with sleep-disordered breathing.

STUDY OBJECTIVES: Obstructive sleep-disordered breathing is accompanied by episodic increases in left ventricle afterload due to large negative swings in intrathoracic pressure and repetitive surges in arterial pressure. Brain natriuretic peptide (BNP) is released by ventricular myocytes in response to pressure and volume overload. It was hypothesized that in children with snoring, overnight change in BNP levels is correlated with severity of disturbance in respiration. DESIGN: Evening and morning plasma levels of BNP were measured in children with snoring referred for polysomnography. SETTING: A sleep disorders laboratory in a university hospital. PARTICIPANTS: Twenty-two children with apnea-hypopnea index (AHI) > or = 5/h (mean +/- SD age, 6.4 +/- 2.5 years), 60 children with AHI < 5/h (mean age, 7 +/- 2.9 years), and 27 control subjects without snoring (mean age, 7.8 +/- 3.7 years) were recruited. MEASUREMENTS AND RESULTS: Overnight change in BNP (log-transformed ratio of morning-to-evening levels) was larger in children with AHI > or = 5/h, compared to those with AHI < 5/h or to control subjects (0.1 +/- 0.19 vs 0.01 +/- 0.14 vs - 0.06 +/- 0.18; p < 0.05). Children with AHI > or = 5/h had an odds ratio of 4.33 (95% confidence interval, 1.34 to 14) for change in peptide levels > 0.15 relatively to subjects with AHI < 5/h. AHI and oxygen saturation of hemoglobin nadir were significant predictors of overnight change in peptide levels. CONCLUSIONS: In children with snoring, overnight increase in BNP levels is correlated with severity of disturbance in respiration during sleep, which may indicate presence of nocturnal cardiac strain.

Adolescent↗
PubMed2006

Microsatellite instability and loss of heterozygosity at the MEN1 locus in lung carcinoid tumors: a novel approach using real-time PCR with melting curve analysis in histopathologic material.

The possible causes and genetic mechanisms of pulmonary carcinoid tumor development are unclear. In this study, we examined genetic alterations at the MEN1 locus in archival material from 15 pulmonary carcinoids. We employed, for the first time in this setting, real-time PCR with melting curve analysis in order to identify loss of heterozygosity (LOH) or microsatellite instability (MI) in two polymorphic markers (PYGM, D11S449) at the MEN1 locus and one additional marker (D11S906) of a putative oncosuppressive region distal to the MEN1 gene. Sequencing data were available in a selected subset of tumors in order to verify the reliability of real-time PCR analysis. We observed LOH at PYGM in 38% of the cases and MI in 13.3% of the cases. Our data indicate that real-time PCR with melting curve analysis is a reliable technique for LOH and MI detection and indicate that genetic errors at the MEN1 locus but also distal to it may be involved in the development of sporadic pulmonary carcinoid tumors.

Adult↗
PubMed2006

Inhibition by mercuric chloride of aquaporin-1 in the parietal sheep peritoneum: an electrophysiologic study.

The peritoneal mesothelium is a barrier to ion transport in peritoneal dialysis. In this study, we used Ussing-chamber experiments to investigate the effect of HgCl2, an aquaporin-1 inhibitor, on the transmesothelial electrical resistance (RTM) of isolated sheep parietal peritoneum. Peritoneal samples from the diaphragm of adult sheep were isolated immediately after the death of the animal and were transferred within 30 minutes to the laboratory in a cooled Krebs-Ringer bicarbonate solution (4 degrees C, pH 7.5) bubbled with 95% O(2)/5% CO2. A planar sheet of the parietal peritoneum was mounted in an Ussing-type chamber and HgCl2 (10(-4) mol/L) was added apically or basolaterally. The RTM was measured before and serially after the addition of the HgCl2. The entire experimental apparatus was held at 37 degrees C, because active ion transport is temperature-dependent. The results presented are the mean +/- standard error of 12 experiments. The control RTM (that is, before the addition of HgCl) was 19.3 +/- 0.38 omega x cm2. Addition of HgCl2 apically induced a decrease in the RTM to 16.25 +/- 0.86 omega x cm2 within 1 minute. When added basolaterally, HgCl2 action was similar, with a rapid reduction in the RTM to 18.1 +/- 0.51 omega x cm2 (p < 0.05). A clear association between the RTM and the active transmesothelial ion transport was shown in previous studies. In the present study, rapid action of HgCl2 on the permeability ofthe parietal peritoneum was observed, resulting in a reduction in the RTM Taken together, these findings indicate that inhibition of aquaporin-1 alters the ionic permeability of the parietal peritoneal membrane.

Animals↗
PubMed2005

Obstructive sleep-disordered breathing and plasma levels of vascular endothelial growth factor in children.

Vascular endothelial growth factor (VEGF) may be one of the pathophysiologic links in the association between obstructive sleep apnea-hypopnea and cardiovascular disease. Morning serum VEGF levels are increased in children with obstructive sleep apnea. However, release of VEGF by platelets and leukocytes during blood clotting may affect its concentration in serum. In the present study, VEGF levels were measured in children with and without habitual snoring using plasma specimens. Evening and morning plasma VEGF concentrations were determined in: (i) 20 children with habitual snoring and apnea-hypopnea index (AHI)5 episodes/h (median age 5; range 1.9-13 years); (ii) 55 children with snoring and AHI<5 episodes/h (median age 6; 2-13 years); and (iii) 25 controls without snoring (median age 6.5; 3-13 years). No differences were identified between the three study groups regarding evening [median 2.5 (range 2.5-174.5) versus 22.5 (2.5-159.4) versus 26.8 (2.5-108) pg/mL; P>0.05] and morning VEGF levels [median 7.7 (range 2.5-120.5) versus 25.1 (2.5-198.4) versus 48.4 (2.5-147.7) pg/mL; P>0.05]. AHI and % sleep time with oxygen saturation of hemoglobin less than 90% were not significant predictors of log-transformed morning VEGF concentrations (P>0.05). In summary, both evening and morning plasma VEGF levels were similar in children with obstructive sleep-disordered breathing of variable severity and in controls without snoring. VEGF may not play an important pathophysiologic role in all cases of obstructive sleep-disordered breathing in childhood.

Adolescent↗
PubMed2005

Comparison of blood pressure measurements in children with and without habitual snoring.

Higher or similar systolic and/or diastolic blood pressure has been recorded in children with sleep apnea compared to subjects with primary snoring or in those with primary snoring compared to controls. To investigate the association between blood pressure and habitual snoring, we studied children in four randomly selected schools in central Greece. A symptom questionnaire was answered by parents, and children's weight, height, and blood pressure were measured. Seven hundred and sixty children (4-14 years old; 352 female) were recruited. Fifty of 760 (6.6%) participants were snoring more than 3 nights/week (habitual snorers). Mean (+/- SD) systolic blood pressure was 106.9 (+/-10.6) mmHg in habitual snorers vs. 107 (+/- 12) in nonhabitual snorers (P > 0.05). Mean diastolic blood pressure was 61.9 (+/- 7.6) in the former vs. 61.8 (+/- 6.8) in the latter (P > 0.05). While age, gender, and body mass index were significant predictors of systolic blood pressure in a general linear model, snoring was not. Similarly, that gender and body mass index but not snoring were significant predictors of diastolic blood pressure. In a community sample of children, habitual snorers do not have higher morning systolic or diastolic blood pressure than nonhabitual snorers.

Adolescent↗
PubMed2005

Obstructive sleep-disordered breathing and fasting insulin levels in nonobese children.

A positive correlation of severity of sleep-disordered breathing with morning fasting insulin levels, which is independent of obesity, was reported in adults and obese children. We hypothesized that both severity of sleep-disordered breathing and relative body mass index predict fasting insulin and homeostasis model assessment (HOMA) index values in nonobese children with habitual snoring. One hundred and ten subjects with habitual snoring (median age, 6 years; range, 2-13 years) underwent polysomnography and measurement of morning fasting insulin and glucose levels. The HOMA index was calculated. Thirty children had an apnea-hypopnea index (AHI) >/= 5 episodes/hr (median, 7.8 episodes/hr; range, 5-42.3 episodes/hr), and 80 subjects had an AHI < 5 episodes/hr (median, 1.9 episodes/hr; range, 0.2-4.9 episodes/hr). Insulin and HOMA index values were similar in children with AHI >/= 5 episodes/hr (median insulin, 4.9 mU/l; range, 1.66-19.9 mU/l; and median HOMA, 1; range, 0.36-4.95) and in subjects with AHI < 5 episodes/hr (median insulin, 5.8 mU/l; range, 0.74-41.1 mU/l; and median HOMA, 1.3; range, 0.13-9.72) (P > 0.05). No significant correlations were identified between insulin or HOMA index values and any polysomnography indices (P > 0.05). When multiple linear regression was carried out, relative body mass index was a significant predictor of log-transformed insulin levels or HOMA index values, but AHI and percentage of sleep time with saturation <95% were not. In conclusion, contrary to findings in adults and in obese children, severity of sleep-disordered breathing is not a significant predictor of fasting insulin or HOMA index values in nonobese children with habitual snoring.

Adolescent↗
PubMed2005

Helicobacter pylori seroprevalence in patients with chronic obstructive pulmonary disease.

An increased seroprevalence of Helicobacter pylori (H. pylori) and especially of the high virulent cytotoxin-associated gene-A (CagA) positive strains has been found in several extragastroduodenal pathologies, characterized by activation of inflammatory mediators. Moreover, it has been reported that the risk of chronic bronchitis may be increased in H. pylori infected patients. The aim of the present study was to assess the seroprevalence of H. pylori and in particular of CagA-positive virulent strains in patients with chronic obstructive pulmonary disease (COPD). We evaluated 126 COPD patients (88 males and 38 females, aged 61.3+/-8.1 years) and 126, age and sex-matched, control subjects. All subjects enrolled underwent an enzyme-linked immunosorbent assay (ELISA) IgG serologic test for H. pylori and CagA protein. The prevalence of H. pylori infection in patients and controls was 77.8% and 54.7%, respectively (P<0.001) and that of CagA-positive H. pylori infection was 53.9% and 29.3%, respectively (P<0.001). Moreover, COPD patients had a significantly increased mean serum concentration of both anti-H. pylori IgG (118.3+/-24.4 vs. 61.9+/-12.9U/ml, P<0.001) and anti-CagA IgG antibodies (33.8+/-3.4 vs. 19.0+/-1.5U/ml, P<0.001). Finally, no statistically significant difference, as regards the spirometric values, was detected between H. pylori infected COPD patients and uninfected ones. In conclusion, H. pylori infection may be associated with COPD. Further studies should be undertaken to clarify the potential underlying pathogenetic mechanisms.

Antigens, Bacterial↗
PubMed2005

Resolution of nocturnal enuresis in snoring children after treatment with nasal budesonide.

Nocturnal enuresis has been associated with obstructive sleep apnea-hypopnea and may resolve after adenotonsillectomy. Nasal corticosteroids have improved symptoms and polysomnography findings in children with snoring. Two children with primary nocturnal enuresis, chronic nasal obstruction, and loud snoring underwent polysomnography. The apnea-hypopnea index was 4.9 and 7.3 episodes/hr, and the oxygen desaturation of hemoglobin index was 4.6 and 5.2 episodes/hr. After administration of budesonide, the frequency of snoring decreased, the polysomnography findings improved, and the enuresis resolved completely. Six months after treatment, both children were still dry at night. Administration of nasal corticosteroids is associated with resolution of enuresis in children with mild obstructive sleep-disordered breathing.

Administration, Intranasal↗