Search PubMed⌕ Search

Biomedical subjects

K Katsouyanni

Publications and source records attributed to K Katsouyanni.

At least 37 records · Page 2Linked to original sources
PubMed2000

Ubiquitous presence of O6-methylguanine in human peripheral and cord blood DNA.

O6-Methylguanine (O6-meG) is a powerful premutagenic lesion that can arise from exposure to methylating agents. Although it has been reported to occur in human DNA, no systematic epidemiological analysis of its occurrence in populations suffering general environmental exposure is available. We report here results from a study of the presence of O6-meG in maternal and cord blood leukocyte DNA of women not knowingly exposed to methylating agents. Using a modification of an already existing method capable of detecting the lesion at levels as low as 16 nmol/molG, the adduct was detected in 31 of 36 maternal and 30 of 36 cord samples, at levels ranging up to 192 nmol/molG. Adduct levels in maternal blood DNA were significantly higher than those in cord blood DNA (P < 0.05), and there was a strong correlation between adduct levels in the two tissues (P < 0.001). In bivariate analysis, no significant association of adduct levels in either tissue and residence air pollution, active and passive smoking status, or eating habits was found. However, intake of fruits/vegetables and of vitamin supplements showed nonstatistically significant trends toward being associated with lower adduct levels in both maternal and cord blood DNA. The same trend was observed after multivariate analysis where all the above variables were controlled for. These findings indicate that premutagenic methylation DNA damage is commonplace in individuals not known to have suffered excessive exposure to environmental methylating agents or their precursors and are compatible with an endogenous origin of this damage, possibly associated with endogenous nitrosation processes.

Adult↗
PubMed2000

Winter mortality in relation to climate.

We report further details of the Eurowinter survey of cold related mortalities and protective measures against cold in seven regions of Europe, and review these with other evidence on the relationship of winter mortality to climate. Data for the oldest subject group studied, aged 65-74, showed that in this vulnerable group, high levels of protection against indoor and outdoor cold at given outdoor temperatures were found mainly in countries with cold winters, and were associated with low levels of excess mortality at a given level of outdoor cold. Regions such as London that had poor protection against cold and/or high baseline mortalities had higher levels of winter excess mortality than expected for the coldness of their winters.

Aged↗
PubMed1999

Vitamins A, C and E and the risk of breast cancer: results from a case-control study in Greece.

Although several dietary compounds are hypothesized to have anticarcinogenic properties, the role of specific micronutrients in the development of breast cancer remains unclear. To address this issue, we assessed intake of retinol, beta-carotene, vitamin C and vitamin E in relation to breast cancer risk in a case-control study in Greece. Eight hundred and twenty women with histologically confirmed breast cancer were compared with 1548 control women. Dietary data were collected through a 115-item semiquantitative food frequency questionnaire. Data were modelled by logistic regression, with adjustment for total energy intake and established breast cancer risk factors, as well as mutual adjustment among the micronutrients. Among post-menopausal women, there was no association between any of the micronutrients evaluated and risk of breast cancer. Among premenopausal women, beta-carotene, vitamin C and vitamin E were each inversely associated with breast cancer risk, but after mutual adjustment among the three nutrients only beta-carotene remained significant; the odds ratio (OR) for a one-quintile increase in beta-carotene intake was 0.84 (95% confidence interval 0.73-0.97). The inverse association observed with beta-carotene intake, however, is slightly weaker than the association previously observed with vegetable intake in these data, raising the possibility that the observed beta-carotene effect is accounted for by another component of vegetables.

Ascorbic Acid↗
PubMed1999

Brain eigenfrequency shifting as a sensitive index of cerebral compliance in an experimental model of epidural hematoma in the rabbit: preliminary study.

OBJECTIVE: To verify brain eigenfrequency shifting after the occurrence of a lesion producing mass effect into the cranial vault. DESIGN: Experimental animal study. SETTING: Laboratory of experimental surgery affiliated with a university critical care department. SUBJECTS: Six adult male New Zealand white rabbits. INTERVENTIONS: A Camino ICP monitor was placed in the parenchyma, and a 5-Fr balloon-tipped catheter and accelerometer were placed into the epidural space. MEASUREMENTS: Before and after the introduction of successive 0.1-mL increments of autologous blood into the balloon, intracranial pressure (ICP) was recorded along with the accelerometer signal obtained during free vibration of the skull triggered by a calibrated hammer. Fast Fourier transformation of the digitized signal provided the eigenfrequency spectrum. The eigenfrequency showing the sharpest decrease after the initial 0.1-mL volume addition was considered as the best frequency, and its variation in response to subsequent 0.1-mL increments represents the brain eigenfrequency shifting. MAIN RESULTS: Brain eigenfrequency shifting to lower values occurs for small blood volume increments (up to 0.2 mL). When volume addition becomes >0.3 mL, brain eigenfrequency shifting to higher values is exhibited. The decrease in best frequency after the initial introduction of 0.1 mL is statistically significant (p = .003), in a range of volume in which no significant intracranial pressure difference appears. The respective variation of ICP is explained using a quadratic curve. For volumes of 0 to 0.1 mL, the change in ICP is not statistically significant (p = .08). CONCLUSIONS: Changes of the brain's physical characteristics by mass addition in the cranial vault can be expressed by brain eigenfrequency shifting. The method seems advantageous because it reliably detects mass additions at low levels where no ICP change occurs. Additionally, it provides serial measurements, and it is less invasive than the currently used methods for intracranial compliance.

Animals↗
PubMed1999

Inhomogeneity in response to air pollution in European children (PEACE project).

OBJECTIVES: The PEACE study is a multicentre panel study of the acute effects of particles with a 50% cut off aerodynamic diameter of 10 microns (PM10), black smoke (BS), sulphur dioxide (SO2), and nitrogen dioxide (NO2) on respiratory health of children with chronic respiratory symptoms. In the complete panels no consistent association between air pollution and respiratory health was found. The study evaluated whether potentially more sensitive subgroups in the panels did show effects of air pollution. METHODS: To evaluate heterogeneity in response to air pollution, effect estimates of air pollution on peak expiratory flow (PEF) and respiratory symptoms were calculated in subgroups based on presence of chronic respiratory symptoms, use of respiratory medication, atopy, sex, and baseline lung function. RESULTS: The association between PEF and air pollution was positive in asthmatic children who used respiratory medication whereas the associations tended to be negative in children who did not use respiratory medication selected only on cough. No consistent association was found among asthmatic children who did not use medication. The association between daily prevalence of symptoms and concentrations of air pollution was not different between these subgroups. CONCLUSION: None of the predefined potentially more sensitive subgroups showed a consistent association between air pollution, PEF, and respiratory symptoms.

Air Pollutants↗
PubMed1999

Recommendations for the monitoring of short-term health effects of air pollution: lessons from the APHEA Multi Centre European Study.

Accumulating evidence from European cities indicates that current levels of ambient air pollution are likely to be associated with detectable effects on daily mortality and hospital admissions. Public health authorities everywhere are concerned about the possible effects of air pollution on the health of their populations but there are no guidelines for how these effects can efficiently be monitored. Furthermore, decisions about air pollution monitoring tend to be made without reference to the epidemiological requirements of health monitoring. The APHEA project (Air Pollution and Health a European Approach) investigated the short-term health effects of air pollution in 15 European cities. Experience gained in this project provides a basis for recommendations to public health and environmental authorities concerning the requirements for a basic health monitoring system. This paper considers the theoretical and practical aspects of a monitoring system and makes recommendations concerning 1) the minimum data set required, 2) the methods of statistical analysis and presentation and 3) Europe-wide coordination of monitoring.

Air Pollution↗
PubMed1998

Time-series analysis of air pollution and cause-specific mortality.

Ten large European cities provided data on daily air pollution as well as mortality from respiratory and cardiovascular mortality. We used Poisson autoregressive models that controlled for trend, season, influenza epidemics, and meteorologic influences to assess the short-term effects of air pollution at each city. We then compared and pooled the city-specific results in a meta-analysis. The pooled relative risks of daily deaths from cardiovascular conditions were 1.02 [95% confidence interval (CI) = 1.01-1.04] for a 50 microg/m3 increment in the concentration of black smoke and 1.04 (95% CI = 1.01-1.06) for an increase in sulfur dioxide levels in western European cities. For respiratory diseases, these figures were 1.04 (95% CI = 1.02-1.07) and 1.05 (95% CI = 1.03-1.07), respectively. These associations were not found in the five central European cities. Eight-hour averages of ozone were also moderately associated with daily mortality in western European cities (relative risk = 1.02; 95% CI = 1.00-1.03 for cardiovascular conditions and relative risk = 1.06; 95% CI = 1.02-1.10 for respiratory conditions). Nitrogen dioxide did not show consistent relations with daily mortality. These results are similar to previously published data and add credence to the causal interpretation of these associations at levels of air pollution close to or lower than current European standards.

Aged↗
PubMed1997

Short-term effects of ambient oxidant exposure on mortality: a combined analysis within the APHEA project. Air Pollution and Health: a European Approach.

The Air Pollution and Health: a European Approach (APHEA) project is a coordinated study of the short-term effects of air pollution on mortality and hospital admissions using data from 15 European cities, with a wide range of geographic, sociodemographic, climatic, and air quality patterns. The objective of this paper is to summarize the results of the short-term effects of ambient oxidants on daily deaths from all causes (excluding accidents). Within the APHEA project, six cities spanning Central and Western Europe provided data on daily deaths and NO2 and/or O3 levels. The data were analyzed by each center separately following a standardized methodology to ensure comparability of results. Poisson autoregressive models allowing for overdispersion were fitted. Fixed effects models were used to pool the individual regression coefficients when there was no evidence of heterogeneity among the cities and random effects models otherwise. Factors possibly correlated with heterogeneity were also investigated. Significant positive associations were found between daily deaths and both NO2 and O3. Increases of 50 micrograms/m3 in NO2 (1-hour maximum) or O3 (1-hour maximum) were associated with a 1.3% (95% confidence interval 0.9-1.8) and 2.9% (95% confidence interval 1.0-4.9) increase in the daily number of deaths, respectively. Stratified analysis of NO2 effects by low and high levels of black smoke or O3 showed no significant evidence for an interaction within each city. However, there was a tendency for larger effects of NO2 in cities with higher levels of black smoke. The pooled estimate for the O3 effect was only slightly reduced, whereas the one for NO2 was almost halved (although it remained significant) when two pollutant models including black smoke were applied. The internal validity (consistency across cities) as well as the external validity (similarities with other published studies) of our results on the O3 effect support the hypothesis of a causal relation between O3 and all cause daily mortality. However, the short-term effects of NO2 on mortality may be confounded by other vehicle-derived pollutants. Thus, the issue of independent NO2 effects requires additional investigation.

Europe↗
PubMed1997

Short-term effects of ambient sulphur dioxide and particulate matter on mortality in 12 European cities: results from time series data from the APHEA project. Air Pollution and Health: a European Approach.

OBJECTIVES: To carry out a prospective combined quantitative analysis of the associations between all cause mortality and ambient particulate matter and sulphur dioxide. DESIGN: Analysis of time series data on daily number of deaths from all causes and concentrations of sulphur dioxide and particulate matter (measured as black smoke or particles smaller than 10 microns in diameter (PM10)) and potential confounders. SETTING: 12 European cities in the APHEA project (Air Pollution and Health: a European Approach). MAIN OUTCOME MEASURE: Relative risk of death. RESULTS: In western European cities it was found that an increase of 50 micrograms/m3 in sulphur dioxide or black smoke was associated with a 3% (95% confidence interval 2% to 4%) increase in daily mortality and the corresponding figure for PM10 was 2% (1% to 3%). In central eastern European cities the increase in mortality associated with a 50 micrograms/m3 change in sulphur dioxide was 0.8% (-0.1% to 2.4%) and in black smoke 0.6% (0.1% to 1.1%). Cumulative effects of prolonged (two to four days) exposure to air pollutants resulted in estimates comparable with the one day effects. The effects of both pollutants were stronger during the summer and were mutually independent. CONCLUSIONS: The internal consistency of the results in western European cities with wide differences in climate and environmental conditions suggest that these associations may be causal. The long term health impact of these effects is uncertain, but today's relatively low levels of sulphur dioxide and particles still have detectable short term effects on health and further reductions in air pollution are advisable.

Air Pollutants↗
PubMed1997

Ambient air pollution exposure and cancer.

Epidemiologic evidence on the relation between ambient air pollution exposure and cancer is reviewed. The well-documented urban/rural difference in lung cancer incidence and the detection of known carcinogens in the atmosphere gave rise to the hypothesis that long-term exposure to air pollution may have an effect on lung cancer risk. However, problems inherent in assessing adequately the exposure of interest led to considerable difficulties in evaluating this effect. Routinely measured air pollutants do not include, as a rule, established carcinogens, and air pollution measurements usually come from fixed-site monitors, making it difficult to estimate individual exposures, especially long-term. The nature of the exposure and associated measurement problems made ecologic comparisons a natural way to approach the study of air pollution effects on lung cancer risk. The descriptive/ecologic studies which have been undertaken after 1950 often had problems with inadequate control of confounding, but, on the whole, provided evidence compatible with the hypothesis that urban and industrial air pollution may have an effect on lung cancer risk. The results of several case-control and cohort studies are described in the present review with emphasis on the exposure metric used. These studies, which control for important potential confounders, suggest that urban air pollution may be a risk factor for lung cancer, with estimated relative risks in the order of up to about 1.5 in most situations.

Air Pollutants↗
PubMed1997

Reproducibility and relative validity of an extensive semi-quantitative food frequency questionnaire using dietary records and biochemical markers among Greek schoolteachers.

BACKGROUND: We evaluated the reproducibility and relative validity of a 190-item semi-quantitative food frequency questionnaire (FFQ) to be used in a large prospective study in the Athens area of Greece. METHODS: In all, 42 men and 38 women, aged 25-67 years, completed two self-administered semi-quantitative FFQ spaced approximately 1 year apart. Within this 1-year interval, participants visited the study centre monthly and completed an interviewer-administered 24-hour diet recall questionnaire. We also collected two venous blood and three 24-hour urine samples from participants at randomly selected periods during the year between the two administrations of the dietary questionnaire. RESULTS: Mean values for intake of most nutrients assessed by the two FFQ were in good agreement while those assessed by the two different dietary methods were reasonably similar for most nutrients. Intraclass correlation coefficients for energy-adjusted nutrient intakes assessed by questionnaires one year apart averaged 0.57 (range 0.24-0.75) and were not substantially different between genders. Correlation coefficients between the energy-adjusted nutrients measured by repeated 24-hour recalls and the semi-quantitative FFQ ranged from 0.25 for beta-carotene and polyunsaturated fats to > 0.50 for saturated fats, cis-linoleic acid, calcium and phosphorus (average: 0.46 for men and 0.39 for women). Reliability and relative validity were very high for alcohol intake. Dietary intakes from the FFQ were significantly correlated to plasma levels of vitamin C, but not beta-carotene or cholesterol. Dietary protein intake assessed by both FFQ was correlated (0.36, 0.30) with average urinary nitrogen excretion levels from three 24-hour urine samples. CONCLUSIONS: These data indicate that the semi-quantitative FFQ is reproducible and provides a reasonably reliable measure of intake. Significant correlations between diet and an independent biochemical marker further corroborate the relative validity of our questionnaire in this Greek population.

Adult↗
PubMed1997

Evidence that adult life risk factors influence the expression of familial propensity to breast cancer.

In the context of a study in Athens comprising 692 cases and 1,261 controls, we have evaluated the effect on breast cancer risk of the joint action of first-degree relative family history and established adult life risk factors. We created a risk score by assigning the value of 1 to women at high risk with respect to any of these risk factors and 0 otherwise, and summing these values, using weights equal to the excess odds ratio. The odds ratio for a tertile increment in the risk score was 1.5 [95% confidence interval (CI) = 1.3-1.8] among women without family history, and 2.3 (95% CI = 1.1-5.1) for women with family history. Our findings imply that women with a family history of breast cancer may benefit disproportionately by reduced exposure to adult life risk factors.

Adult↗
PubMed1997

An assessment, and reproducibility of food frequency data provided by hospital controls.

In order to assess the comparability and reproducibility of information from a questionnaire used in a case-control study on digestive tract cancers conducted in Italy, a total of 400 subjects were randomly selected from a large sample of hospital controls and contacted at home to repeat the interview. Of these, 294 (73%) subjects were re-interviewed. Mean values of intake were computed for the 400 subjects selected, and among the 294 responders for the first and second interview. These values were comparable, most of them being within a 10% range. Spectrum correlation coefficient (rs) values of consumption between the first and second interview were > 0.65 for consumption of pastries, pasta or rice, bread, fish, milk, green vegetables, eggs and apples; between 0.50 and 0.65 for meat, chicken, liver, ham, cold cuts, cheese, fruit, cabbage, carrots, tomatoes, peppers, salad, citrus fruit and melon; and lower than 0.50 for a few infrequently eaten foods. For all foods, the estimated average weekly intake in the second interview increased consistently and substantially with increasing tertile of the first interview. This study shows a satisfactory comparability of dietary information from subjects interviewed at home with that provided during their original interview in the hospital, and a good reproducibility of information collected in the two settings.

Case-Control Studies↗
PubMed1997

Urban air pollution and emergency admissions for asthma in four European cities: the APHEA Project.

BACKGROUND: A study was undertaken to assess the combined association between urban air pollution and emergency admissions for asthma during the years 1986-92 in Barcelona, Helsinki, Paris and London. METHODS: Daily counts were made of asthma admissions and visits to the emergency room in adults (age range 15-64 years) and children (< 15 years). Covariates were short term fluctuations in temperature and humidity, viral epidemics, day of the week effects, and seasonal and secular trends. Estimates from all the cities were obtained for the entire period and separately by warm or cold seasons using Poisson time-series regression models. Combined associations were estimated using meta-analysis techniques. RESULTS: Daily admissions for asthma in adults increased significantly with increasing ambient levels of nitrogen dioxide (NO2) (relative risk (RR) per 50 micrograms/m3 increase 1.029, 95% CI 1.003 to 1.055) and non-significantly with particles measured as black smoke (RR 1.021, 95% CI 0.985 to 1.059). The association between asthma admissions and ozone (O3) was heterogeneous among cities. In children, daily admissions increased significantly with sulphur dioxide (SO2) (RR 1.075, 95% CI 1.026 to 1.126) and non-significantly with black smoke (RR 1.030, 95% CI 0.979 to 1.084) and NO2, though the latter only in cold seasons (RR 1.080, 95% CI 1.025 to 1.140). No association was observed for O3. The associations between asthma admissions and NO2 in adults and SO2 in children were independent of black smoke. CONCLUSIONS: The evidence of an association between air pollution at current urban levels and emergency room visits for asthma has been extended to Europe. In addition to particles, NO2 and SO2--by themselves or as a constituent of a pollution mixture--may be important in asthma exacerbations in European cities.

Adolescent↗
PubMed1997

The regional production of cytokines and lactate in sepsis-related multiple organ failure.

In order to explore whether an organ-specific pattern in cytokine and lactate concentrations exists in patients with multiple organ failure (MOF), we measured the cytokines interleukin-1beta (IL-1beta), IL-6, and tumor necrosis factor-alpha (TNF-alpha), and lactate in blood taken from the hepatic vein, pulmonary capillaries, and peripheral veins of 10 patients with MOF with hepatic involvement (MOF-HI), eight patients with MOF and adult respiratory distress syndrome (MOF-ARDS), and five head-injured patients (controls). Ten additional patients participated in a study of arteriovenous pulmonary concentration gradients of these substances. For statistical analysis, nonparametric tests and analysis of variance (ANOVA) were used. The regional concentrations of these substances exhibited a different pattern in the two MOF groups. In the MOF-HI group, mean +/- SD cytokines IL-1beta and IL-6 (pg/ml) were respectively 216 +/- 100 and 461 +/- 343 in the hepatic sinusoidal blood; 149 +/- 52 and 293 +/- 204 in pulmonary capillary blood; and 148 +/- 105 and 234 +/- 162 in peripheral venous blood. In the MOF-ARDS group the corresponding levels were 180 +/- 103 and 235 +/- 124; 235 +/- 94 and 280 +/- 108; and 130 +/- 77 and 194 +/- 127. The TNF-alpha levels also exhibited the same pattern. The mean +/- SD corresponding levels (mmol/L) for lactate in the MOF-HI group were 3.1 +/- 1.8, 1.5 +/- 0.3, and 1.2 +/- 0.6, and in the MOF-ARDS group were 1.1 +/- 0.9, 1.8 +/- 1.1, and 1.0 +/- 0.2, respectively. The differences in the levels of all substances between the liver and lungs in the two MOF groups were statistically significant (p < 0.003). In the study of transpulmonary gradients it was shown that the levels of cytokine and lactate were lower in arterial blood than in mixed venous blood in MOF-HI patients, whereas the opposite was true in MOF-ARDS patients. In this study, we found that in MOF, cytokines and lactate are secreted from the most severely affected organs.

Aged↗
PubMed1997

Air pollution and daily admissions for chronic obstructive pulmonary disease in 6 European cities: results from the APHEA project.

We investigated the short-term effects of air pollution on hospital admissions for chronic obstructive pulmonary disease (COPD) in Europe. As part of a European project (Air Pollution and Health, a European Approach (APHEA)), we analysed data from the cities of Amsterdam, Barcelona, London, Milan, Paris and Rotterdam, using a standardized approach to data eligibility and statistical analysis. Relative risks for daily COPD admissions were obtained using Poisson regression, controlling for: seasonal and other cycles; influenza epidemics; day of the week; temperature; humidity and autocorrelation. Summary effects for each pollutant were estimated as the mean of each city's regression coefficients weighted by the inverse of the variance, allowing for additional between-cities variance, as necessary. For all ages, the relative risks (95% confidence limits (95% CL)) for a 50 microg x m(-3) increase in daily mean level of pollutant (lagged 1-3 days) were (95% CL): sulphur dioxide 1.02 (0.98, 1.06); black smoke 1.04 (1.01, 1.06); total suspended particulates 1.02 (1.00, 1.05), nitrogen dioxide 1.02 (1.00, 1.05) and ozone (8 h) 1.04 (1.02, 1.07). The results confirm that air pollution is associated with daily admissions for chronic obstructive pulmonary disease in European cities with widely varying climates. The results for particles and ozone are broadly consistent with those from North America, though the coefficients for particles are substantially smaller. Overall, the evidence points to a causal relationship but the mechanisms of action, exposure response relationships and pollutant interactions remain unclear.

Air Pollution↗