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Biomedical subjects

G Kyriazis

Publications and source records attributed to G Kyriazis.

9 recordsLinked to original sources
PubMed2002

Tumor necrosis factor-alpha serum levels, weight loss and tissue oxygenation in chronic obstructive pulmonary disease.

Weight loss has been recognized as a feature of advanced emphysema and a factor of poor prognosis, but its mechanisms remain obscure. Studies have demonstrated high serum concentrations of TNF-a (cachexin) in chronic obstructive pulmonary disease (COPD) patients with emphysema. Pink puffers (PP) COPD patients have worse tissue oxygenation when compared with blue bloaters (BB) COPD patients. Consequently, PP patients would become cachectic, whereas BB patients with better tissue oxygenation would not. The aim of this study is to test the hypothesis that malnutrition in emphysema is a cytokine-mediated marker of chronic progressive tissue hypoxia. Thirty male COPD patients, without clinical or laboratory evidence of infection and severe air way obstruction (FEV1 < 1.5 l) were allocated: 16 as pink puffers (PP) and 14 as blue bloaters (BB). Lung function measurements included FEV1, FVC, RV, TLC, DLCO and arterial blood gases on room air. TNF-a serum levels were measured by immunoenzymic method (ELISA). Tissue oxygenation was assessed from oxygen delivery (DO2), PvO2 and oxygen extraction ratio (O2ER) obtained after right heart catheterization with Swan Ganz catheter. PP patients demonstrated lower DLCO and higher TLC, FRC and PaO2 from BB. We found that oxygen delivery was better in our BB than in PP patients (CI 2.9 +/- 0.2 vs 2.5 +/- 0.4 l/min/m2--P < 0.01, DO2 16.1 +/- 2.1 vs 13.1 +/- 0.2 ml/min/kg--P < 0.001) and the same was found for tissue oxygenation (PvO2 34.6 +/- 2.9 vs 31.2 +/- 3.8 mmHg--P < 0.01, O2ER 0.27 +/- 0.02 vs 0.34 +/- 0.06%--P < 0.001). The TNF-a values were higher in PP (31.3 +/- 26 pg/ml vs 15.2 +/- 9.9 pg/ml--P < 0.05) and their percent fat-free mass (%FFM) was 49.6 +/- 11.5 vs 42 +/- 8%--P < 0.001. We found that COPD patients with lower DO2 had increased TNF-a levels; but the correlations between TNF-a serum levels and PvO2 or O2ER were not statistically significant. TNF-a levels were elevated in PP patients with tissue hypoxia and may be a factor contributing to the weight loss of these patients.

Cell Hypoxia↗
PubMed1997

Clinical evaluation of four different high-flux hemodialyzers under conventional conditions in vivo.

Four types of high-flux hemodialyzers, Primus 2000 (high-flux polysulfone 2.0 m2), Altra-Flux 170 G (cellulose diacetate 1.7 m2), FLX-15 GW (polyester-polymer alloy 1.5 m2) and PAN-85 DX (polyacrylonitrile 1.7 m2) were evaluated in vivo. A total of 12 stable chronic hemodialysis patients participated in the study and each type of dialyzer was tested once in 9 of them. Blood samples for the measurement of BUN, creatinine, phosphate, uric acid, albumin and beta2-microglobulin (beta2M) were drawn before and 5 min after the end of the study dialysis. During dialysis, which was performed in all patients with a blood flow rate of 250 ml/min for 240 min, the dialysate (550-600 ml/min) was collected every hour and samples were drawn for the measurements of all the above substances. The mean total amount of low-molecular substances removed per session by each dialyzer was very close to 19.5 g for urea, 2.0 g for creatinine, 0.9 g for phosphate and 1 g for uric acid. The one-third (30-33%) of the above amounts were removed during the first hour of dialysis. Dialyzers' clearances for creatinine and uric acid were significantly higher in Primus dialyzer comparing to FLX-15 GW (p < 0.05) while the clearance for urea showed a borderline significance (p = 0.055). No difference was found either among Altra-Flux 170 G, FLX-15 GW and PAN-85 DX or between Primus and PAN-85 DX dialyzers. Phosphate clearance did not show any difference among the four dialyzers. The lowest amount of albumin removed per session was 0.75 g by PAN-85 DX and the highest 1.8 g by FLX-15 GW, while the equivalents for beta2M were 80 mg by Altra-Flux 170 G and 142 mg by PAN-85 DX. A significant adsorption of beta2M on these dialysis membranes was indicated by the combination of a satisfactory serum beta2M reduction ratio (post-/predialysis values = 0.52, 0.77, 0.60, 0.55) with a reduced beta2M clearance (23.9, 13.6, 20.2, 25.1 ml/min). During the first hour of dialysis, in comparison to the following time, the highest amounts of albumin and beta2M (expressed as percentage of total) were removed by the Primus 2000 dialyzer. Our results indicate that under conventional conditions small differences in the surface area of the high-flux dialyzers are unimportant regarding the removal of low molecules. However, the composition of the membrane seems to play an important role in the removal of high-molecular substances.

Acrylic Resins↗
PubMed1975

A simple staining method for vaginal smears using red ink.

In adult rhesus monkeys each phase of 37 menstrual cycles was accurately classified by cellular identification of vaginal smears stained with red ink. This technic was simple, quick, and inexpensive, and produced well-stained slides in a few seconds.

Animals↗
PubMedDate not supplied

The prevalence of allergic asthma and rhinitis in children of Polichni, Thessaloniki.

AIM: To define the prevalence of asthma and rhinitis in primary school children in the Polichni Municipality of the city of Thessaloniki. METHODS AND RESULTS: The parents of 2005 students living in the area of Polichni completed a questionnaire for the detection of pulmonary disease in childhood. Of 493 children who gave positive answers to the questions about allergies, asthma and rhinitis, 203 were excluded after an interview with the parents, because they suffered from either atopic dermatitis or drug allergy or had normal lgE levels. Of the remaining children, 290 were further examined: methacholine test was positive in 109, exercise test was positive in 67, nasal provocation test with histamine was positive in 244, and rhinodilation test with tramazoline was positive in 206. Skin prick tests were positive in 142 children (90 to grass-cereal pollen, 66 to acarea and 59 to Parietaria officinalis). CONCLUSIONS: We found that 168 children suffered from rhinitis, 84 from both asthma and rhinitis concurrently and 38 from asthma alone. Only 37 % of the parents knew that their children suffered from asthma, while even fewer (32 %) knew that their children had rhinitis. The prevalence of asthma was 6.1 % and that of rhinitis was 12.6 % among children aged 9-12 years in the area of Polichni, Thessaloniki. Childhood rhinitis and asthma seem to be frequently underdiagnosed and undertreated.

Adult↗
PubMedDate not supplied

Respiratory effects in workers processing dried tobacco leaves.

OBJECTIVES: The aim of this study was to examine the pollution level of the occupational environment and to investigate the effects of occupational exposure to tobacco dust on the respiratory system of tobacco workers. No such study has previously been conducted in Greece, which is one of the main tobacco-producing countries. METHODS: A total of 1,020 seasonal and permanent tobacco workers (188 men and 832 women) were studied in a factory in Thessaloniki. The study included: 1) completion of a questionnaire (British Medical Research Council 1986), 2) spirometry and 3) rhinomanometry. At the same time, tobacco dust levels in the working environment were measured. As controls, 469 workers (87 men and 382 women) at a Thessaloniki hospital were used. Seventy six workers with nasal symptoms underwent: 1) special nasal provocation test with tobacco dust antigen, 2) skin prick tests, and 3) measurement of total IgE, specific IgE and specific IgG against tobacco protein. RESULTS: Very high levels of total suspended dust were found in work site air (45.3-54.4 mg/m3). The prevalence of chronic bronchitis was 8.7 % versus 20.6 % in controls. Chronic obstructive pulmonary disease was found in 13 workers (1.3 %) and in 16 controls (3.4 %). FEV1 %pred, FVC %pred and the FEV1/FVC ratio were lower in controls, whereas FEF25-75 % %pred was lower in workers. There were no workers with bronchial asthma or extrinsic allergic alveolitis. Rhinitis was reported by 27.3 % of the workers versus 17.9 % of controls, whereas nasal flows were 563+/-211 versus 645 +/- 321 ml/sec, respectively. According to the results of skin prick tests, six workers were sensitized to dried tobacco leaf dust. CONCLUSIONS: The results of our study do not support an association between the development of chronic diseases of the lower respiratory system and pollutants associated with the processing of dried tobacco leaves. In contrast, an association between disorders of the upper airways and tobacco dust in work sites is postulated.

Adult↗
PubMedDate not supplied

Comparative efficacy of salbutamol and salmeterol in exercise-induced asthma.

This study compared the protection provided by salbutamol and salmeterol against exercise-induced asthma. Asthmatic patients (n = 12) with exercise-induced asthma were exercised submaximally for 6 min on a treadmill 1, 6 and 12 h after inhalation of 200 micrograms salbutamol or 50 micrograms salmeterol. Each patient also took baseline exercise 1 h after two puffs of placebo. Two days later the drugs were administered in a double-blind trial of crossover design with an interval of 48 h between the two treatments. The main parameters measured were: air flow with a Wright flowmeter and mediator concentrations (histamine, leucotriene and prostaglandin D2 measured by radioimmunoassay) in venous blood, which was withdrawn before and 4 min after each exercise period. The maximum percentage bronchoconstriction recorded following placebo was 29 +/- 4% and following salbutamol inhalation it was 4 +/- 4%, 20 +/- 13%, 27 +/- 10%, respectively, for the exercise periods performed 1, 6 and 12 h after inhalation of the drug. Following salmeterol, the corresponding figures were 3 +/- 4%, 3 +/- 3% and 11 +/- 9%. The concentrations of mediator in plasma were significantly increased after exercise. Salbutamol and salmeterol intake reduced these concentrations both when the patients were at rest and following the exercise period. This effect of both drugs on the mediators corresponded with the protection they provided against exercise-induced asthma and was maintained for 12 h after salmeterol inhalation and for 6 h after salbutamol inhalation.

Administration, Inhalation↗
PubMedDate not supplied

Correlation of rCBF (SPECT), CSF tau, and cognitive function in patients with dementia of the Alzheimer's type, other types of dementia, and control subjects.

BACKGROUND: The diagnosis of Alzheimer's disease (AD) during life remains difficult and a definite diagnosis of AD relies on histopathological confirmation at post-mortem or by cerebral biopsy. It is well known that levels of tau proteins are consistently and significantly increased in the cerebrospinal fluid (CSF) of Alzheimer's patients versus levels in normal controls. However, the sole use of this biochemical marker as a test for AD is hampered by mediocre specificity, since tau concentrations may also be elevated in certain other neurological disorders (OND). Studies of the regional cerebral blood flow (rCBF) are widely performed because of their convenience and usefulness in a variety of neurological disorders. Most studies have reported high diagnostic accuracy for brain perfusion single-photon emission tomography (SPECT) in Alzheimer's disease. METHODS: In order to improve specificity, in this study, correlation of 99mTc-HMPAO SPECT scanning and CSF tau protein levels was made in 117 patients with AD, 67 patients with OND (26 of which had other dementias), and 23 age-matched controls. Means and standard deviations of tau protein levels were 297, 42 +/- 221, 12 in AD patients and 78, 07 +/- 98, 51 in patients with OND (p = 0.0006). No correlation was noted between CSF tau protein levels and age, duration of the disease, and neuropsychological scores of mini-mental state examination (MMSE), Cambridge Cognitive Examination (CAMCOG), and Functional Rating Scale for Symptoms of Dementia (FRSSD). FINDINGS: There was a bilateral parietal and temporal hypoperfusion in patients with AD in SPECT in comparison to normal subjects (p < 0.05) and there was a statistical correlation between this hypoperfusion and neuropsychological tests, such as MMSE and CAMCOG (p < 0.01). There was no correlation between tau protein levels and hypoperfusion in SPECT. INTERPRETATION: Conclusively, the correlation between elevated levels of tau proteins and hypoperfusion in SPECT in AD patients therefore cannot improve the specificity of tests in AD and this means that the determination of CSF tau proteins levels is not a specific diagnostic test for AD.

Aged↗
PubMedDate not supplied

Superoxide dismutase activity in early and advanced Parkinson's disease.

Superoxide dismutase (SOD) is an enzyme system that is implicated in the oxidant stress model of Parkinson's disease (PD) pathogenesis. This study was designed to assess SOD activity in whole blood and red blood cells of PD patients in early and advanced stages of the disease. Fifteen PD patients in stage I and II (group A) and 15 in stage III and IV (group B) as well as 15 normal controls were included in the study. SOD activity was assessed in whole blood and red blood cells. Group B patients showed a statistically significant decrease of SOD activity in whole blood and in red blood cells. A negative correlation between SOD activity and duration of the disease was observed, while there was no relationship between L-Dopa treatment and SOD activity. Our results indicate that a defect in SOD activity develops over time in PD. Whether this is a later manifestation of antioxidant mechanism deterioration or simply an epiphenomenon remains unclear.

Aged↗