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Author Lerchl, A.; Schindler, C.; Eichhorn, K.; Kley, F.; Erren, T.C.
Title Indirect blue light does not suppress nocturnal salivary melatonin in humans in an automobile setting Type Journal Article
Year 2009 Publication Journal of Pineal Research Abbreviated Journal J Pineal Res
Volume 47 Issue 2 Pages 143-146
Keywords Human Health; Adolescent; Adult; *Automobiles; Circadian Rhythm/physiology; Humans; *Lighting; Male; Melatonin/metabolism/*secretion; Salivary Glands/*secretion; Statistics, Nonparametric
Abstract In 2007, the International Agency for Research on Cancer (IARC) classified shift work that involves circadian disruption as being probably carcinogenic to humans (Group 2A). In this context, light exposure during the night plays a key role because it can suppress nocturnal melatonin levels when exposures exceed a certain threshold. Blue light around 464 nm is most effective in suppressing melatonin because of the spectral sensitivity of melanopsin, a recently discovered photopigment in retinal ganglion cells; the axons of these cells project to the suprachiasmatic nucleus, a circadian master clock in the brain. Due to advances in light technologies, normal tungsten light bulbs are being replaced by light-emitting diodes which produce quasi-monochromatic or white light. The objective of this study was to assess whether the light-melanopsin-melatonin axis might be affected in automobiles at night which employ the new generation diodes. To this end, we have tested in an experimental automobile setting whether indirect blue light (lambda(max) = 465 nm) at an intensity of 0.22 or 1.25 lx can suppress salivary melatonin levels in 12 male volunteers (age range 17-27 years) who served as their own controls. Daytime levels were low (2.7 +/- 0.5 pg/mL), and night-time levels without light exposure were high (14.5 +/- 1.1 pg/mL), as expected. Low-intensity light exposures had no significant effect on melatonin levels (0.22 lx: 17.2 +/- 2.8 pg/mL; P > 0.05; 1.25 lx: 12.6 +/- 2.0 pg/mL; P > 0.05). It is concluded that indirect blue light exposures in automobiles up to 1.25 lx do not cause unintentional chronodisruption via melatonin suppression.
Address School of Engineering and Science, Jacobs University, D-28759 Bremen, Germany. a.lerchl@jacobs-university.de
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0742-3098 ISBN Medium
Area Expedition Conference
Notes PMID:19555449 Approved no
Call Number LoNNe @ kagoburian @ Serial (down) 777
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Author Kujanik, S.; Mikulecky, M.
Title Circadian and ultradian extrasystole rhythms in healthy individuals at elevated versus lowland altitudes Type Journal Article
Year 2010 Publication International Journal of Biometeorology Abbreviated Journal Int J Biometeorol
Volume 54 Issue 5 Pages 531-538
Keywords Human Health; Acclimatization/physiology; Aged; *Altitude; Anoxia/etiology; Cardiac Complexes, Premature/*physiopathology; Circadian Rhythm/*physiology; Electrocardiography, Ambulatory; Heart Rate/*physiology; Humans; Male; Middle Aged; Reference Values; Time Factors
Abstract We defined chronobiologic norms for supraventricular and ventricular single extrasystoles (SV and VE, respectively) in healthy older males in lowland areas. The study was extended to higher altitudes, where hypobaric hypoxia was expected to increase extrasystole frequency, while perhaps not changing rhythmicity. In healthy men (lowland n = 37, altitude n = 22), aged 49-72 years, mean numbers of SVs and VEs were counted over a 24-h period. Cosinor regression was used to test the 24-h rhythm and its 2nd-10th harmonics. The resulting approximating function for either extrasystole type includes its point, 95% confidence interval of the mean, and 95% tolerance for single measurement estimates. Separate hourly differences (delta) between altitude and lowland (n = 59) were also analysed. Hourly means were significantly higher in the mountains versus lowland, by +0.8 beats/h on average for SVs, and by +0.9 beats/h for VEs. A relatively rich chronogram for VEs in mountains versus lowland exists. Delta VEs clearly display a 24-h component and its 2nd, 3rd, 4th and 7th harmonics. This results in significantly higher accumulation of VEs around 8.00 a.m., 11.00 a.m. and 3.00 p.m. in the mountains. The increase in extrasystole occurrence in the mountains is probably caused by higher hypobaric hypoxia and resulting sympathetic drive. Healthy men at elevated altitudes show circadian and several ultradian rhythms of single VEs dependent on the hypoxia level. This new methodological approach--evaluating the differences between two locations using delta values--promises to provide deeper insight into the occurrence of premature beats.
Address Dept of Physiology, Faculty of Medicine, Pavol Jozef Safarik University, Trieda SNP 1, 040 66 Kosice, Slovak Republic. stefan.kujanik@upjs.sk
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-7128 ISBN Medium
Area Expedition Conference
Notes PMID:20195873 Approved no
Call Number LoNNe @ kagoburian @ Serial (down) 774
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Author Kloog, I.; Portnov, B.A.; Rennert, H.S.; Haim, A.
Title Does the modern urbanized sleeping habitat pose a breast cancer risk? Type Journal Article
Year 2011 Publication Chronobiology International Abbreviated Journal Chronobiol Int
Volume 28 Issue 1 Pages 76-80
Keywords Human Health; ged; Alcohol Drinking/adverse effects; Breast Neoplasms/*etiology; Case-Control Studies; Circadian Rhythm/*radiation effects; Female; Humans; Light/*adverse effects; Middle Aged; Odds Ratio; Risk Factors; *Sleep; Urbanization
Abstract Due to its disruptive effects on circadian rhythms and sleep deprivation at night, shiftworking is currently recognized as a risk factor for breast cancer (BC). As revealed by the present analysis based on a comparative case-control study of 1679 women, exposure to light-at-night (LAN) in the “sleeping habitat” is significantly associated with BC risk (odds ratio [OR] = 1.220, 95% confidence interval [CI] = 1.118-1.311; p < .001), controlling for education, ethnicity, fertility, and alcohol consumption. The novelty of the present research is that, to the best of the authors' knowledge, it is the first study to have identified an unequivocal positive association between bedroom-light intensity and BC risk. Thus, according to the results of the present study, not only should artificial light exposure in the working environment be considered as a potential risk factor for BC, but also LAN in the “sleeping habitat.”
Address Department of Natural Resources and Environmental Management, Graduate School of Management, University of Haifa, Haifa, Israel
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0742-0528 ISBN Medium
Area Expedition Conference
Notes PMID:21182407 Approved no
Call Number LoNNe @ kagoburian @ Serial (down) 770
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Author Kanikowska, D.; Sugenoya, J.; Sato, M.; Shimizu, Y.; Inukai, Y.; Nishimura, N.; Iwase, S.
Title Seasonal variation in blood concentrations of interleukin-6, adrenocorticotrophic hormone, metabolites of catecholamine and cortisol in healthy volunteers Type Journal Article
Year 2009 Publication International Journal of Biometeorology Abbreviated Journal Int J Biometeorol
Volume 53 Issue 6 Pages 479-485
Keywords Human Health; Adrenocorticotropic Hormone/*blood; Catecholamines/*blood; Circadian Rhythm/*physiology; Humans; Hydrocortisone/*blood; Interleukin-6/*blood; Male; Reference Values; *Seasons; Young Adult
Abstract We investigated seasonal changes in blood concentrations of interleukin-6 (IL-6), adrenocorticotrophic hormone (ACTH), metabolites of catecholamine (VMA, HVA, and 5-HIAA) and cortisol in humans. Eight volunteers were investigated at four times during the year (February, May, August and October) at latitude 35 degrees N. The mean ambient temperature at the collection periods was higher in the order of summer > autumn approximately spring > winter. Changes in mood were also monitored by a profile of mood states (POMS) questionnaire. The concentration of IL-6 was significantly higher in winter and summer than in spring and autumn. The concentrations of ACTH, HVA and VMA were significantly higher in summer. No seasonal variation was detected in cortisol. There were significant differences among the seasons in subscale tension and anger in the POMS questionnaire; the tension subscale showed significant differences between spring and autumn, with a higher score in spring. The results demonstrate that Il-6, ACTH, HVA and VMA exhibit statistically significant seasonal rhythms, which might have important diagnostic and therapeutic implications.
Address Department of Physiology, Aichi Medical University School of Medicine, Nagakute, Aichi 480-1195, Japan. dkanikowska@hotmail.com
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0020-7128 ISBN Medium
Area Expedition Conference
Notes PMID:19506914 Approved no
Call Number LoNNe @ kagoburian @ Serial (down) 768
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Author Grundy, A.; Richardson, H.; Burstyn, I.; Lohrisch, C.; SenGupta, S.K.; Lai, A.S.; Lee, D.; Spinelli, J.J.; Aronson, K.J.
Title Increased risk of breast cancer associated with long-term shift work in Canada Type Journal Article
Year 2013 Publication Occupational and Environmental Medicine Abbreviated Journal Occup Environ Med
Volume 70 Issue 12 Pages 831-838
Keywords Human Health; Adult; Aged; Aged, 80 and over; Breast Neoplasms/epidemiology/*etiology/metabolism; British Columbia/epidemiology; Case-Control Studies; Female; Humans; Menopause; Middle Aged; Occupational Diseases/*epidemiology; Ontario/epidemiology; Receptors, Estrogen/metabolism; Receptors, Progesterone/metabolism; Risk Factors; Tumor Markers, Biological/metabolism; Work Schedule Tolerance/*physiology; Young Adult
Abstract OBJECTIVES: Long-term night work has been suggested as a risk factor for breast cancer; however, additional studies with more comprehensive methods of exposure assessment to capture the diversity of shift patterns are needed. As well, few previous studies have considered the role of hormone receptor subtype. METHODS: Relationships between night shift work and breast cancer were examined among 1134 breast cancer cases and 1179 controls, frequency-matched by age in Vancouver, British Columbia, and Kingston, Ontario. Self-reported lifetime occupational histories were assessed for night shift work, and hormone receptor status obtained from tumour pathology records. RESULTS: With approximately one-third of cases and controls ever employed in night shift work, associations with duration demonstrated no relationship between either 0-14 or 15-29 years, while an association was apparent for >/=30 years (OR=2.21, 95% CI 1.14 to 4.31). This association with long-term night shift work is robust to alternative definitions of prolonged shift work, with similar results for both health and non-health care workers. CONCLUSIONS: Long-term night shift work in a diverse mix of occupations is associated with increased breast cancer risk and not limited to nurses, as in most previous studies.
Address Department of Public Health Sciences and Queen's Cancer Research Institute, Queen's University, Kingston, Ontario, Canada
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1351-0711 ISBN Medium
Area Expedition Conference
Notes PMID:23817841 Approved no
Call Number LoNNe @ kagoburian @ Serial (down) 757
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