Vitamin E as a treatment for ulcerative dermatitis in C57BL/6 mice and strains with a C57BL/6 background.
ABSTRACT In this study, we fed a standard NIH-31 diet fortified with vitamin E to C57BL/6 mice and strains of mice with a C57BL/6 background that had spontaneously developed ulcerative dermatitis (UD). In addition to the therapeutic response to increased levels of vitamin E, we also defined the occurrence of UD within our facility in terms of age, sex, coat color, and lesion location on the body. Mice with spontaneous UD were fed a vitamin E-fortified diet (3000 IU/kg) for a period of 8 weeks and entered the study without regard to vendor source, age, sex, coat color, or the site or number of UD lesions. We found that lesions occurred most commonly on the dorsal cervical and scapular regions and spared the ventral abdomen and thorax. No sex or coat color predilection was noted for the development of UD, however males were older than females at the time of lesion development. Of 71 mice, 32 (45%) had complete lesion re-epithelialization with hair regrowth. Complete lesion repair was not influenced by sex, age, or coat color. The average time to complete lesion repair ranged from 2 to 5 weeks, and there was no correlation with sex or coat color. The positive response to vitamin E suggests that protection from oxidative injury may play a role in the resolution of UD lesions and offers veterinarians and investigators a new treatment option with ease of compliance.
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ABSTRACT: Adaptive responses to low doses of low LET radiation occur in all organisms thus far examined, from single cell lower eukaryotes to mammals. These responses reduce the deleterious consequences of DNA damaging events, including radiation-induced or spontaneous cancer and non-cancer diseases in mice. The adaptive response in mammalian cells and mammals operates within a certain window that can be defined by upper and lower dose thresholds, typically between about 1 and 100 mGy for a single low dose rate exposure. However, these thresholds for protection are not a fixed function of total dose, but also vary with dose rate, additional radiation or non-radiation stressors, tissue type and p53 functional status. Exposures above the upper threshold are generally detrimental, while exposures below the lower threshold may or may not increase either cancer or non-cancer disease risk.Dose-Response 01/2010; 8(2):192-208. DOI:10.2203/dose-response.09-039.Mitchel · 1.23 Impact Factor
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ABSTRACT: The purpose of this study was to ascertain if prophylactic ingestion of a diet rich in vitamin E would prevent or impede the development of ulcerative dermatitis in mice on a C57BL/6 background. Mice were fed either a standard mouse diet, vitamin E (99 IU/kg), or a mouse diet fortified with vitamin E (3000 IU/kg) after weaning. Cases of ulcerative dermatitis were recorded by individuals unmasked to the diet assignment. The incidence of ulcerative dermatitis in a retrospective cohort of mice on standard diet was compared with the group on the diet fortified with vitamin E. Age was associated with ulcerative dermatitis in standard diet and vitamin E fortified diet groups, r = 0.43, p-value < 0.0001 and r = 0.18, p-value < 0.02, respectively. The average age of incidence for ulcerative dermatitis in the mice fed the standard diet was 89 weeks and for the mice fed the vitamin E diet it was 41 weeks. The unadjusted odds ratio comparing the incidence of ulcerative dermatitis between the two diet groups was 4.6 with a 95% confidence interval of (2.44, 8.58), χ(2) p-value < 0.0001. Therefore, there was an association between the diets and ulcerative dermatitis, with the mice on the vitamin E fortified diet having almost five times the odds of having ulcerative dermatitis compared with mice on the standard diet. Incidence of ulcerative dermatitis was not influenced by sex or genotype. Our study results show that a diet fortified in vitamin E initiated at weaning does not prevent or impede the development of ulcerative dermatitis in mice on a C57BL/6 background and may accelerate development when administered to young mice.Scandinavian Journal of Laboratory Animal Science 01/2010; 37(4):253-259. · 0.21 Impact Factor
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ABSTRACT: The influence of low-dose-rate chronic radiation exposure and adaptive responses on non-cancer diseases is largely unknown. We examined the effect of low-dose/low-dose-rate fractionated or single exposures on spontaneous chronic ulcerative dermatitis in Trp53 normal or heterozygous female C57BL/6 mice. From 6 weeks of age, mice were exposed 5 days/week to single daily doses (0.33 mGy, 0.7 mGy/h) totaling 48, 97 or 146 mGy over 30, 60 or 90 weeks, and other Trp53+/- mice were exposed to a single dose of 10 mGy (0.5 mGy/min) at 20 weeks of age. The 90-week exposure produced an adaptive response, decreasing both disease frequency and severity in Trp53+/+ mice and extending the life span of older animals euthanized due to severe disease. The 30- or 60-week exposures had no significant protective or detrimental effect. In contrast, the chronic, fractionated exposure for 30 or 60 weeks significantly increased the frequency and severity of the disease in older Trp53+/- mice, significantly decreasing the life span of the animals required to be euthanized for disease. Similarly, the single 10-mGy exposure also increased disease frequency in older animals. However, the chronic, fractionated exposure for 90 weeks prevented these detrimental effects, with disease frequency and severity not different from unexposed controls. We conclude that very low-dose fractionated exposures can induce a protective adaptive response in both Trp53 normal and heterozygous mice, but that a lower threshold level of exposure, similar in both cases, must first be passed. In mice with reduced Trp53 functionality, doses below the threshold can produce detrimental effects.Radiation Research 01/2008; 168(6):716-24. DOI:10.1667/RR1124.1 · 2.45 Impact Factor