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Featured researches published by Xenophon Zavitsanos.


The Lancet | 1983

PSYCHOLOGICAL STRESS AND FATAL HEART-ATTACK - THE ATHENS (1981) EARTHQUAKE NATURAL EXPERIMENT

Dimitrios Trichopoulos; Xenophon Zavitsanos; Klea Katsouyanni; Anastasia Tzonou; Panagiota Dalla-Vorgia

The effects of acute and subacute psychological stress caused by a sudden general disaster on mortality from atherosclerotic heart disease (underlying cause) and cardiac events (proximate cause) were investigated by comparing total and cause-specific mortality during the days after a major earthquake in Athens in 1981 with the mortality during the surrounding month and the corresponding periods of 1980 and 1982. There was an excess of deaths from cardiac and external causes on the days after the major earthquake, but no excess of deaths from cancer and little, if any, excess of deaths from other causes. The excess mortality was more evident when atherosclerotic heart disease was considered as the underlying cause (5, 7, and 8 deaths on the first three days, respectively; background mean deaths per day 2.6; upper 95th centile 5) than when cardiac events in general were considered as the proximate cause (9, 11, and 14 deaths on the first three days, respectively; background mean 7.1, upper 95th centile 12).


Clinical Infectious Diseases | 2009

Impact of Hepatitis B Virus Infection on the Progression of AIDS and Mortality in HIV-Infected Individuals: A Cohort Study and Meta-Analysis

Georgios K. Nikolopoulos; Dimitrios Paraskevis; Eleni Hatzitheodorou; Zissis Moschidis; Vana Sypsa; Xenophon Zavitsanos; Victoria Kalapothaki; Angelos Hatzakis

BACKGROUND The effect of hepatitis B virus (HBV) infection on the natural history of human immunodeficiency virus (HIV) disease remains uncertain. Therefore, a retrospective cohort study was conducted to examine the influence of HIV-HBV coinfection on AIDS development and overall mortality. Moreover, our results were added to those of previous studies in a literature-based meta-analysis. METHODS Serum samples obtained from HIV-seropositive patients from 1984 through 2003 were retrospectively tested for hepatitis B surface antigen. Multivariable analyses were performed using Poisson and logistic regression models. For meta-analytic purposes, eligible articles were identified and relevant data were abstracted. Pooled estimates of effect were calculated applying fixed and random effects models. RESULTS The prevalence of chronic HBV infection (documented hepatitis B surface antigen seropositivity for >6 months) among 1729 HIV-positive patients was approximately 6%. The multivariable analyses in our primary study revealed no significant impact of concomitant HIV-HBV infection on progression to AIDS and all-cause mortality. However, a meta-analysis performed on data from 12,382 patients enrolled in 11 studies revealed a significant effect of HIV-HBV coinfection on overall mortality (pooled effect estimate, 1.36; 95% confidence interval, 1.12-1.64). The increased rate of death among coinfected individuals was observed in the meta-analyses of studies conducted both before (pooled effect estimate, 1.60; 95% confidence interval, 1.07-2.39) and after (pooled effect estimate, 1.28; 95% confidence interval, 1.03-1.60) commencement of highly active antiretroviral therapy. CONCLUSIONS HIV-HBV coinfection seems to affect all-cause mortality, and strategies to reduce liver damage in patients coinfected with HIV and HBV are justified.


Epidemiology | 1992

Urban living, tobacco smoking, and chronic obstructive pulmonary disease: a study in Athens.

Anastasia Tzonou; George Maragoudakis; Dimitrios Trichopoulos; Xenophon Zavitsanos; Ioanna Dimopoulou; Nektaria Toupadaki; Jenny Kremastinou

We studied the relation of urban living and tobacco smoking to the development of chronic obstructive pulmonary disease. The study was based on 110 incident cases of chronic obstructive pulmonary disease between 50 and 60 years of age who were permanent residents of Athens and 400 control patients hospitalized for traumatic and orthopedic conditions in the same hospitals at the same time. All subjects were interviewed about their smoking habits, place of birth, history of past residence, and years of schooling. We found that subjects with more education have a reduced risk of developing chronic obstructive pulmonary disease, with 4 additional years of schooling corresponding to a 30% reduction of risk. We also found that those who have lived all their lives in urban areas (mostly in Athens) have a twofold greater risk of chronic obstructive pulmonary disease compared with people who have lived exclusively or partly in rural areas before settling in Athens. Finally, we found that smokers have a 10-fold relative risk of developing chronic obstructive pulmonary disease, and this risk is strongly dependent on the number of cigarettes consumed per day. The findings of the present study suggest that air pollution, or another aspect of the urban environment, can be an important contributor to the development of chronic obstructive pulmonary disease.


Epidemiology | 2000

Birth order, as a proxy for age at infection, in the etiology of hepatocellular carcinoma.

Hannah Kuper; Chung-Cheng Hsieh; Sherri O. Stuver; Lorelei A. Mucci; Anastasia Tzonou; Xenophon Zavitsanos; Pagona Lagiou; Dimitrios Trichopoulos

First-born and second-born children are exposed to common infections after enrollment at school, whereas later-born children are exposed to these infections earlier through their older siblings. We have evaluated whether birth order is a risk factor for hepatitis B virus (HBV)-related, hepatitis C virus (HCV)-related, and apparently virus-unrelated hepatocellular carcinoma (HCC) in a large case-control study that included 333 HCC cases and 632 controls. In comparison with controls who were carriers of hepatitis B surface antigen (HBsAg), HBsAg-positive HCC cases were more likely to have been later-born children (odds ratio per increase in birth order = 2.0; 95% confidence interval = 1.2–3.6). There was no such evidence for anti-HCV-positive cases compared with anti-HCV-positive controls or for virus-negative HCC cases compared with virus-negative controls. We conclude that early infection with HBV increases the risk of HBV carriers to develop HCC, over and beyond its role in facilitating the establishment of a carrier state.


Cancer Causes & Control | 1992

Liveborn children and risk of hepatocellular carcinoma

Anastasia Tzonou; Xenophon Zavitsanos; Chung-Cheng Hsieh; Dimitrios Trichopoulos

Clinical, animal, and epidemiologic evidence indicates that exogenous steroids influence the risk of hepatocellular carcinoma (HCC) and a recent study suggested that parity also may increase the risk of this tumor in women. The latter hypothesis was evaluated in the data from a case-control study which was carried out in Athens and covered 166 male and 19 female cases of HCC, and 381 male and 51 female hospital controls. Among males, there was no association between the number of liveborn children and risk of HCC, whereas among women, there was a suggestive positive association. Compared with women with one or two children, the relative risk for HCC was 0.6 among nulliparous women, 1.3 among those with three or four children and 1.7 among those with five or more children. The association of parity with risk of HCC was limited to women who were positive for hepatitis-B surface antigen (HBsAg) and was not confounded by hepatitis-C virus infection or tobacco smoking. The small number of HCC cases does not permit firm conclusions. If confirmed, however, these results would provide the foundation for a practical preventive advice that could be given to women who are positive for HBsAg.


International Journal of Std & Aids | 2010

HIV/HBV co-infection and rate of antiretroviral treatment change after highly active antiretroviral treatment initiation in a cohort of HIV-infected patients in Greece

Georgios K. Nikolopoulos; Dimitrios Paraskevis; Eleni Hatzitheodorou; Zissis Moschidis; Vana Sypsa; Xenophon Zavitsanos; Victoria Kalapothaki; Angelos Hatzakis

The current study investigated the impact of human immunodeficiency virus (HIV)/hepatitis B virus (HBV) co-infection on the rate of change of antiretroviral drugs after the initiation of highly active antiretroviral treatment (HAART). The data on 1425 HIV-positive patients with recorded serology for hepatitis B surface antigen (HBsAg) were retrospectively analysed. The estimated rate of treatment change was slightly higher in the HBsAg-positive group (0.57 per year) compared with the HBsAg-negative group (0.50 per year). Although this difference was insignificant in multivariable modelling, the confidence intervals of the estimates barely included unity. Antiretroviral drug family, calendar period, prior exposure to antiretrovirals and the diagnosis of acquired immunodeficiency syndrome were independently associated with the number of drug alterations. A slight impact of co-infection on the frequency of treatment change after the beginning of HAART cannot be excluded. However, the paucity of studies on this issue necessitates the conduct of further research.


JAMA | 1991

Hepatitis B and C Viruses and Their Interaction in the Origin of Hepatocellular Carcinoma

E. Kaklamani; Dimitrios Trichopoulos; A. Tzonou; Xenophon Zavitsanos; Y. Koumantaki; Angelos Hatzakis; Chung-Cheng Hsieh; S. Hatziyannis


International Journal of Cancer | 1987

Hepatitis B virus, tobacco smoking and ethanol consumption in the etiology of hepatocellular carcinoma

Dimitrios Trichopoulos; Anastasia Tzonou; Evangelia Kaklamani; Xenophon Zavitsanos; Yvonne Koumantaki; N. E. Day; Nubia Muñoz; Antonia Trichopoulou


American Journal of Epidemiology | 1992

Age at First Establishment of Chronic Hepatitis B Virus Infection and Hepatocellular Carcinoma Risk A Birth Order Study

Chung-Cheng Hsieh; Anastasia Tzonou; Xenophon Zavitsanos; Evagelia Kaklamani; Shou-Jen Lan; Dimitrios Trichopoulos


The Lancet | 1988

THE 1987 ATHENS HEATWAVE

Klea Katsouyanni; D. Trichopoulos; Xenophon Zavitsanos; Giota Touloumi

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Anastasia Tzonou

National and Kapodistrian University of Athens

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Chung-Cheng Hsieh

University of Massachusetts Medical School

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Klea Katsouyanni

National and Kapodistrian University of Athens

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Angelos Hatzakis

National and Kapodistrian University of Athens

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Anna Kalandidi

National and Kapodistrian University of Athens

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D. Trichopoulos

National and Kapodistrian University of Athens

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Emmanuel Agapitos

National and Kapodistrian University of Athens

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Evangelia Kaklamani

National and Kapodistrian University of Athens

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