Home  About us  Contact
 

Exposure Schedules (exposure + schedule)

Distribution by Scientific Domains
Life Sciences33%

Selected Abstracts

Reduction of the UV burden to indoor tanners through new exposure schedules: a pilot study

PHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 2 2006
Sharon A. Miller
Background: The development of new pigmentation (tan) in human skin after UV exposure requires several days. Once it is developed, the tan can last for weeks. Current recommendations for tanning exposure schedules in the USA (FDA Letter to Manufacturers: Policy on maximum timer interval and exposure schedule for sunlamps, August 21, 1986) allow exposures three times per week for the development of a tan, and one to two times per week for maintenance exposures. However, this policy is often interpreted in the indoor tanning industry as allowing three exposures per week on a continuous basis. We believe that the reduction of the recommended cumulative dose to indoor tanners should be explored. Two approaches for achieving this are (1) decreasing the number of exposures and (2) increasing the time interval between exposures. To explore such changes, we conducted a pilot study. Methods: The pilot study involved three exposure schedules (evaluated on each of six subjects) that evolved throughout the course of the study. Digital photography, visual assessment and diffuse reflectance spectrometry were used to assess skin color changes. The six pilot subjects were studied for 8,18 weeks. The changes in skin color obtained through the use of the different exposure schedules were compared with changes reported by Caswell (Caswell M, The kinetics of the tanning response to tanning bed exposures, Photodermatol Photoimmunol Photomed 2000: 16: 10,14) who used schedules based on current recommendations. Results: Two out of the three experimental schedules produced tans comparable with those reported by Caswell. In these two schedules, cumulative doses were a factor of 2,3 below doses from current schedules. Conclusion: The UV burden to indoor tanners can be substantially reduced without compromising the cosmetic effect. These results need to be confirmed in a larger study. [source]

UV Exposure, Genetic Targets in Melanocytic Tumors and Transgenic Mouse Models,

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 1 2005
Frank R. de Gruijl
ABSTRACT The genetic changes and corruption of kinase activity in melanomas appear to revolve around a central axis: mitogenic signaling along the RAS pathway down to transcription regulation by pRB. Epidemiological studies point to the importance of ultraviolet (UV) radiation in the etiology of melanoma, but where and how UV radiation is targeted to contribute to the oncogenic signaling remains obscure. Animal models of melanoma genesis could serve to clarify this issue, but many of these models are not responsive to UV exposure. Most interesting advances have been made by using transgenic mice that carry genetic defects that are known to be relevant to human melanoma: specifically, dysfunction in the tumor suppressive action of p161NK4a or a receptor tyrosine kinase/RAS pathway, that is constitutively activated in melanocytes. The latter types of mice appear to be most responsive to (neonatal) UV exposure. Whether this is due to a general increase in target cells by melanocytosis and a paucity or complete lack of pigment, or a possible UV-induced response of the promoter,enhancer of the transgene or a genuinely independent and additional genetic alteration caused by UV exposure needs to be established. Importantly, the full effect of UV radiation needs to be ascertained in mice with different pigmentation by varying the wavelengths, UV-B versus UV-A1, and the exposure schedules, i.e. neonatal versus adult and chronic versus intermittent overexposure. Intermittent UV-B overexposure deserves special attention because it most strongly evokes proliferative responses in melanocytes. [source]

Reduction of the UV burden to indoor tanners through new exposure schedules: a pilot study

PHOTODERMATOLOGY, PHOTOIMMUNOLOGY & PHOTOMEDICINE, Issue 2 2006
Sharon A. Miller
Background: The development of new pigmentation (tan) in human skin after UV exposure requires several days. Once it is developed, the tan can last for weeks. Current recommendations for tanning exposure schedules in the USA (FDA Letter to Manufacturers: Policy on maximum timer interval and exposure schedule for sunlamps, August 21, 1986) allow exposures three times per week for the development of a tan, and one to two times per week for maintenance exposures. However, this policy is often interpreted in the indoor tanning industry as allowing three exposures per week on a continuous basis. We believe that the reduction of the recommended cumulative dose to indoor tanners should be explored. Two approaches for achieving this are (1) decreasing the number of exposures and (2) increasing the time interval between exposures. To explore such changes, we conducted a pilot study. Methods: The pilot study involved three exposure schedules (evaluated on each of six subjects) that evolved throughout the course of the study. Digital photography, visual assessment and diffuse reflectance spectrometry were used to assess skin color changes. The six pilot subjects were studied for 8,18 weeks. The changes in skin color obtained through the use of the different exposure schedules were compared with changes reported by Caswell (Caswell M, The kinetics of the tanning response to tanning bed exposures, Photodermatol Photoimmunol Photomed 2000: 16: 10,14) who used schedules based on current recommendations. Results: Two out of the three experimental schedules produced tans comparable with those reported by Caswell. In these two schedules, cumulative doses were a factor of 2,3 below doses from current schedules. Conclusion: The UV burden to indoor tanners can be substantially reduced without compromising the cosmetic effect. These results need to be confirmed in a larger study. [source]

Extremely low frequency-modulated static magnetic fields to treat cancer: A pilot study on patients with advanced neoplasm to assess safety and acute toxicity

BIOELECTROMAGNETICS, Issue 8 2004
Flavio Ronchetto
Abstract Results of a toxicity pilot human study approved by the competent ethical Committee are reported. Eleven patients with heavily pre-treated advanced cancer were enrolled in a pilot study with different schedules of time exposure to static magnetic fields (MF), amplitude modulated by ELF. An area including the neck, thoracic and abdomen was MF exposed daily, 5 days/week for 4 weeks according to two different schedules: 20 min daily (4 patients) and 70 min daily (7 patients). ECOG performance status was 1 (2 patients), 2 (8 patients), 3 (1 patient). Toxicity was assessed according to WHO criteria. ECG, Chest X-ray, physical examination, blood cell count and complete blood chemistry were performed before and at the end of the treatment. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) elevation (grade 2 toxicity) in 1 patient and microscopic urinary abnormalities in 5 patients were the only negative effects observed. We conclude that MF can be safely administrated according to the MF exposure schedules. Bioelectromagnetics 25:563,571, 2004. © 2004 Wiley-Liss, Inc. [source]