How to have an effective academic sabbatical: recommendations for what to do and what to avoid.

Sabbaticals - i.e., academic sabbaticals, sabbatical leaves, sabbatical semesters - provide faculty members with a unique opportunity to engage in scholarly projects.

Physical workload and accelerated occurrence of lumbar spine diseases: risk and rate advancement periods in a German multicenter case-control study.

Objective: In a German multicenter case-control study of lumbar disc diseases, we calculated risk and rate advancement periods (RAP) for physical workload.

Methods: Patients aged 25-70 years with clinically and radiologically verified lumbar disc herniation (286 males, 278 females) or symptomatic lumbar disc narrowing (145 males, 206 females) were compared with population control subjects (453 males and 448 females). For this analysis, all manual handling of objects of about ≥5 kg and postures with trunk inclination of ≥20 °, as assessed by technical experts, were included in the calculation of cumulative lumbar load, determined by biomechanical model calculations.

Work-related lesions of the supraspinatus tendon: a case-control study.

Objectives: To examine the dose-response relationship between cumulative duration of work with highly elevated arms (work above shoulder level) as well as of manual material handling and ruptures of the supraspinatus tendon in a population-based case-control study.

Methods: In 14 radiologic practices, we recruited 483 male patients aged 25-65 with radiographically confirmed partial (n = 385) or total (n = 98) supraspinatus tears associated with shoulder pain. A total of 300 male control subjects were recruited.

Research into the chronodisruption-cancer theory: the imperative for causal clarification and the danger of causal reductionism.

A cascade of investigations into the validity of the chronodisruption-cancer theory (CD-CT), proposed 2008 in Neuroendocrinology Letters as a synthesis of abundant experimental and tantalizing - but still limited - epidemiological data, can be expected in coming years. In view of the possible public health relevance of the suggested links between chronodisruption, defined as the disruption of the temporal organization or order of biological rhythmicity over days and seasons, and the development of disease, including cancer, we provide practical aspects which should be considered for the planning, conduct and the very interpretation of such studies. The interrelated considerations address two facets: first, the critical necessity of causal clarification can be evinced appropriately by Poole's earlier contribution to the Journal.

Epigenetics: origins and implications for cancer epidemiology.

This paper provides information on the evolution of the 'epigenetics' concept since Aristotle and draws attention to the importance of epigenetic implications for cancer epidemiology in the years to come. Clearly, to understand origins of the concept of epigenetics, it is worthwhile to consider historical arguments associated with evolution. Equally clearly, in the last half of the 20th century, great advances in the understanding of epigenetics and, more specifically, great advances in the understanding of epigenetics in cancer have been made.

Light Hygiene: Time to make preventive use of insights--old and new--into the nexus of the drug light, melatonin, clocks, chronodisruption and public health.

Light is, clearly, a key to life on Earth and light, equally clearly, determines biological rhythmicity in organisms. Light does the latter by setting internal or endogenous clocks which allow a multitude of species, including man, to adjust their lives to changing external or environmental conditions. Critical changes over time occur from day to night and throughout the year.

Shift work, chronodisruption and cancer?--The IARC 2007 challenge for research and prevention and 10 theses from the Cologne Colloquium 2008.

In October of 2007, an IARC panel of 24 scientists systematically evaluated epidemiologic, experimental, and mechanistic data and concluded that shift work that involves circadian or chronodisruption is probably carcinogenic in humans. In view of the possible scope of the problem--shift work is widespread and unavoidable on one hand and breast cancer and prostate cancer, which may be causally associated with chronodisruption, are epidemic worldwide on the other--German representatives of science and occupational medicine discussed the experimental and epidemiologic background and possible implications of the challenge identified by the International Agency for Research on Cancer (IARC) at a colloquium in Cologne in September 2008. This overview summarizes the key ideas presented at the Cologne Colloquium and offers 10 theses concerning the need for targeted studies and the necessity to develop possible means of prevention.

Defining chronodisruption.

When the International Agency for Research on Cancer (IARC) classified shift-work that involves circadian disruption as probably carcinogenic to humans in 2007, this was the prelude to extensive experimental and epidemiological research in coming years. Indeed, with some 20% of people worldwide being engaged in some type of work at unusual times, including the night, it is a must to investigate, and to clarify as soon as possible, the biologically plausible links via circadian disruption with epidemic cancers such as of the breast or prostate. Surprisingly, neither the IARC information available so far nor the general literature provides a clear definition of what the critical component in the postulated chain of causation, namely circadian disruption, is.

A generalized theory of carcinogenesis due to chronodisruption.

For two decades, research has been suggested and conducted into the causation and development of cancers in seemingly diverse and unrelated populations such as blind individuals, shift-workers, flight personnel, Arctic residents and subsets of sleepers. One common denominator of these investigations is "melatonin". Another common denominator is that all these studies implicitly pursued the validity of the so-called "melatonin hypothesis", of a corollary and of associated predictions which can be united in our proposed theory of "carcinogenesis due to chronodisruption".

Is exposure to silica associated with lung cancer in the absence of silicosis? A meta-analytical approach to an important public health question.

Objective: This report investigates epidemiologically whether exposure to silica is associated with lung cancer risks in individuals without silicosis.

Methods: We searched the PubMed reference data base from 1966 through 1/2007 for reports of lung cancer in silica-exposed persons without and with silicosis. To explore heterogeneity between studies, a multi-stage strategy was employed.

Diagnostic and prognostic value of soluble mesothelin-related proteins in patients with malignant pleural mesothelioma in comparison with benign asbestosis and lung cancer.

Introduction And Methods: We investigated the diagnostic and prognostic value of soluble mesothelin-related proteins (SMRP) in sera from patients with newly diagnosed malignant pleural mesothelioma (MPM) (n = 100), MPM patients at tumor relapse (n = 29), primary lung cancer (n = 139), and benign asbestosis (n = 75) using Mesomark--enzyme-linked immunosorbent assay kit (Fujirebio Diagnostics, Malvern, PA).

Results: SMRP concentrations were significantly higher in MPM compared with benign asbestosis (p < 0.001) or lung cancer (p < 0.

Clockwork blue: on the evolution of non-image-forming retinal photoreceptors in marine and terrestrial vertebrates.

This paper presents a hypothesis that could explain why blue light appears to dominate non-image-forming (NIF) ocular photoreception in marine as well as terrestrial vertebrates. Indeed, there is more and more evidence suggesting that 'novel' retinal photoreceptors, which are sensitive to blue light and were only discovered in the 1990s, could be a feature shared by all vertebrates. In our view, blue light photoreception evolved and persisted as NIF photoreception because it has been useful in the colonisation of extensive photo-dependent oceanic habitats and facilitated the move of vertebrates from an aquatic to a terrestrial environment.

The case for a posteriori hypotheses to fuel scientific progress.

A priori hypotheses are considered a cornerstone of the scientific method. A posteriori hypotheses, on the contrary, are judged by many as inappropriate and are hardly ever acknowledged as such. Such practice is inadequate.

Could visible light contribute to the development of leukaemia and other cancers in children?

This paper suggests to rigorously test the hypothesis that there are causal links between visible light and the development of leukaemia and other cancers in children. Light can be considered as a candidate risk factor because it suppresses melatonin biosynthesis which may play a role in a series of anticancer defences. Indeed, melatonin may offer some protection against all "hallmarks of cancer" [i.

Does light cause internal cancers? The problem and challenge of an ubiquitous exposure.

Visible light of sufficient intensity and duration inhibits melatonin biosynthesis, and experimental studies suggest that melatonin may protect against cancer. From a public health point of view it is important to verify or falsify the hypothesis that artificial light--or even sunlight itself--suppresses melatonin production sufficiently to increase the risk of developing cancers of internal organs in man. Epidemiology is a discipline that can contribute to in-vivo verification of experimental findings.

A meta-analysis of epidemiologic studies of electric and magnetic fields and breast cancer in women and men.

This paper reviews 43 publications that provide information about possible associations between exposure to electric and magnetic fields (EMF) at work or at home and risks of breast cancer in women and men. Estimation of relative risk associated with exposure was possible for 24 studies among women and 15 among men. The data are grouped in relation to gender of study subjects, type of study, geographical location, and method used to assess exposure, with corresponding precision-weighted estimates of pooled relative risks (RRs).