Epidemiological studies of radiation carcinogenesis

To protect the public’s health from exposure to physical, chemical, and microbiological agents, it is important that any policy be based on rigorous scientifically based research. The concept of “linear no-threshold” (LNT) has been implemented to provide guideline exposures to these agents. The practical limitation to testing this hypothesis is to provide sufficient samples for experimental or epidemiological studies. While there is no universally accepted understanding of most human diseases, there seems to be better understanding of cancer that might help resolve the “LNT” model. The public’s concern, after being exposed to radiation, is the potential of producing cancer. The most rigorous hypothesis of human carcinogenesis is the “multistage, multimechanism” chemical carcinogenesis model. The radiation carcinogenesis LNT model, rarely, if ever, built it into their support. It will be argued that this multistage, multimechanism model of carcinogenesis, involving the “initiation” of a single cell by a mutagen event, followed by chronic exposure to threshold levels of epigenetic agents or conditions that stimulate the clonal expansion of the “initiated” cell, can convert these benign cells to become invasive and metastatic. This “promotion” process can be interrupted, thereby preventing these initiated cells from transitioning to the “progression” process of invasion and metastasis.

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Road traffic injuries in developing countries: a comprehensive review of epidemiological studies

Tropical Medicine & International Health ◽

10.1046/j.1365-3156.1997.d01-296.x ◽

1997 ◽

Vol 2 (5) ◽

pp. 445-460 ◽

Cited By ~ 12

Author(s):

W. Odero ◽

P. Garner ◽

A. Zwi

Keyword(s):

Developing Countries ◽

Road Traffic ◽

Epidemiological Studies ◽

Comprehensive Review ◽

Road Traffic Injuries

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Plague in the Late Medieval Nordic Countries: Epidemiological Studies

Population Studies ◽

10.1080/0032472031000148826 ◽

1995 ◽

Vol 49 (3) ◽

pp. 537-539

Author(s):

Frederik Pedersen

Keyword(s):

Epidemiological Studies ◽

Nordic Countries ◽

Late Medieval

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Suicidal Behavior in German Adolescents

Zeitschrift für Kinder- und Jugendpsychiatrie und Psychotherapie ◽

10.1024/1422-4917/a000331 ◽

2015 ◽

Vol 43 (1) ◽

pp. 39-45 ◽

Cited By ~ 4

Author(s):

Joana Straub ◽

Ferdinand Keller ◽

Nina Sproeber ◽

Michael G. Koelch ◽

Paul L. Plener

Keyword(s):

Suicidal Behavior ◽

Suicide Attempts ◽

Depression Scale ◽

Epidemiological Studies ◽

Present Sample ◽

Manic Symptoms ◽

Symptoms Of Depression ◽

Adolescent Sample ◽

History Of ◽

Sum Scores

Objective: Research in adults has identified an association between bipolar disorder and suicidal behavior. This relationship, however, has been insufficiently investigated in adolescents to date. Methods: 1,117 adolescents from 13 German schools (mean age = 14.83, SD = .63; 52.7% females) completed an extended German version of the Center for Epidemiological Studies Depression Scale (CES-D), which assesses depressive and manic symptoms during the last week, as well as the Self-Harm Behavior Questionnaire (SHBQ) for the assessment of lifetime suicidal behavior. Results: In the present sample 39.4% of the girls and 23.1% of the boys reported lifetime suicidal thoughts and 7.1% of the girls as well as 3.9% of the boys a lifetime history of suicide attempts. 18.7% of the adolescent sample revealed elevated symptoms of depression and 9% elevated levels of mania symptoms. Elevated sum scores of depression and mania were associated with a higher number of suicidal ideations and suicide attempts. A block-wise regression analysis revealed that sum scores of depression and mania predicted suicidal ideations best. Concerning suicide attempts, the best predictors were age as well as depression and mania sum scores. Conclusions: Suicidal behavior was reported more often when adolescents demonstrate symptoms of mania as well as symptoms of depression than when they demonstrate only depressive symptoms. The presence of bipolar symptoms in adolescents should alert clinicians to the heightened possibility of suicidal behavior.

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Zur Anwendung der CES-D bei älteren Menschen: Dimensionsstruktur und Meßartefakte

Diagnostica ◽

10.1026//0012-1924.46.1.29 ◽

2000 ◽

Vol 46 (1) ◽

pp. 29-37 ◽

Cited By ~ 7

Author(s):

Herbert Matschinger ◽

Astrid Schork ◽

Steffi G. Riedel-Heller ◽

Matthias C. Angermeyer

Keyword(s):

Mental State ◽

Latent Class ◽

Mini Mental State Examination ◽

Depression Scale ◽

Epidemiological Studies ◽

Partial Credit ◽

Examination Score ◽

State Examination

Zusammenfassung. Beim Einsatz der Center for Epidemiological Studies Depression Scale (CES-D) stellt sich das Problem der Dimensionalität des Instruments, dessen Lösung durch die Konfundierung eines Teilkonstruktes (“Wohlbefinden”) mit Besonderheiten der Itemformulierung Schwierigkeiten bereitet, da Antwortartefakte zu erwarten sind. Dimensionsstruktur und Eignung der CES-D zur Erfassung der Depression bei älteren Menschen wurden an einer Stichprobe von 663 über 75-jährigen Teilnehmern der “Leipziger Langzeitstudie in der Altenbevölkerung” untersucht. Da sich die Annahme der Gültigkeit eines partial-credit-Rasch-Modells sowohl für die Gesamtstichprobe als auch für eine Teilpopulation als zu restriktiv erwies, wurde ein 3- bzw. 4-Klassen-latent-class-Modell für geordnete Kategorien berechnet und die 4-Klassen-Lösung als den Daten angemessen interpretiert: Drei Klassen zeigten sich im Sinne des Konstrukts “Depression” geordnet, eine Klasse enthielt jene Respondenten, deren Antwortmuster auf ein Antwortartefakt hinwiesen. In dieser Befragtenklasse wird der Depressionsgrad offensichtlich überschätzt. Zusammenhänge mit Alter und Mini-Mental-State-Examination-Score werden dargestellt. Nach unseren Ergebnissen muß die CES-D in einer Altenbevölkerung mit Vorsicht eingesetzt werden, der Summenscore sollte nicht verwendet werden.

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Epidemiological Trends in Attempted Suicide in Adolescents and Young Adults Between 1996 and 2004

Crisis ◽

10.1027/0227-5910.30.3.115 ◽

2009 ◽

Vol 30 (3) ◽

pp. 115-119 ◽

Cited By ~ 10

Author(s):

Stephanie De Munck ◽

Gwendolyn Portzky ◽

Kees Van Heeringen

Keyword(s):

Young Adults ◽

Attempted Suicide ◽

Suicide Attempts ◽

Epidemiological Studies ◽

Adolescents And Young Adults ◽

University Hospital ◽

International Studies ◽

Suicide Attempters ◽

Increased Risk ◽

Epidemiological Trends

Background: Notwithstanding the epidemiological studies indicating an increased risk of attempted suicide among adolescents and young adults, there is a scarcity of international studies that examine long-term epidemiological trends in rates and characteristics of this vulnerable group. Aims: This article describes the results of a 9-year monitoring study of suicide attempts in adolescents and young adults referred to the Accident and Emergency Department of the Gent University Hospital (Belgium). Methods: Between January 1996 and December 2004, trends, sociodemographic, and methodrelated characteristics of suicide attempts were assessed by a psychiatrist on data sheets. Results: Attempted suicide rates declined from 1996 to 2001 and then rose until 2004, but did not exceed previous rates. During the 9 years of monitoring, there was a preponderance of female suicide attempters, except for 1997. Rates of attempts and of fatal suicide were negatively correlated. Significantly more males than females deliberately injured themselves. Younger attempters, especially females, significantly more often poisoned themselves with analgesics. In nearly one in five attempts, alcohol was used in combination with other methods, and alcohol intake was more commonly observed in older suicide attempters. Nearly half of the adolescents were identified as repeaters. Conclusions: The results of this study warrant further monitoring of trends and characteristics of young suicide attempters.

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Family-, Media-, and School-Related Risk Factors of Video Game Addiction

Journal of Media Psychology Theories Methods and Applications ◽

10.1027/1864-1105/a000093 ◽

2013 ◽

Vol 25 (3) ◽

pp. 118-128 ◽

Cited By ~ 53

Author(s):

Florian Rehbein ◽

Dirk Baier

Keyword(s):

Risk Factors ◽

Video Game ◽

Age Groups ◽

Well Being ◽

Epidemiological Studies ◽

Prevention Measures ◽

School Life ◽

Video Game Addiction ◽

Effective Prevention ◽

Game Addiction

In recent years, a variety of epidemiological studies have provided empirical data on the prevalence of video game addiction (GA) in different age groups. However, few studies investigated the causes of GA and could explain why video game playing as a widespread phenomenon leads to a comparatively small percentage of addicted players. Additionally, the existing longitudinal studies mainly consider psychological trait variables and neglect the possible explanatory value of predictors in socialization regarding media availability, media use, and family and everyday school life. In this paper, the results of a two-wave longitudinal study comprising a sample of students from Grades 4 to 9 (N = 406) are presented. The data show that 15-year-old video game addicts had already exhibited a number of specific risk factors at the age of 10. Students from single-parent families seem to be particularly at risk, as are students with low experienced school well-being and with a weaker social integration in class. The data also indicate that problematic use of video games in childhood increases the risk of GA in adolescence. Male students are especially vulnerable for developing GA. The results of this study are an important contribution to understanding risk factors for GA in adolescents, thereby laying the groundwork for effective prevention measures.

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