Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0235394 (wasting)
 8,040 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In mice, the recessive mutation hairless (hr) controls the cutaneous response to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) but its influence on TCDD's systemic toxicity is unclear. To clarify this, we compared the effects of lactational TCDD exposure on standardized litters of newborn HRS/J mice homozygous for either hr or + that were fostered by haired dams exposed to 0, 6, 8 or 12 micrograms TCDD/kg body weight on postnatal day 0. At 12 micrograms/kg, TCDD was lethal to both haired and hairless pups. At the lower doses (6 and 8 micrograms/kg) the survival of hr/hr pups was significantly lower than +/+ pups. Affected pups succumbed following a 1 to 2-day period of cachexia and wasting. As has been reported for other mouse strains, TCDD exposure impacted on their neonatal development and lessened the time to eye opening for both haired and hairless pups. However, the hairless animals were affected at lower doses than were the haired. The results of this study document that the hr/hr genotype does influence the systemic toxicity of TCDD in mice.
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PMID:The hr locus and the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in newborn mice. 771 66

Exposure to (solar) UVB radiation gives rise to mutations in the p53 tumor suppressor gene that appear to contribute to the earliest steps in the molecular cascade towards human and murine skin cancer. To examine in more detail the role of p53, we studied UVB-induced carcinogenesis in hairless p53 knock-out mice. The early onset of lymphomas as well as early wasting of mice interfered with the development of skin tumors in p53 null-mice. The induction of skin tumors in the hairless p53+/- mice was accomplished by daily exposure to two different UV-doses of approximately 450 J/m2 and 900 J/m2 from F40 lamps corresponding to a fraction of about 0.4 and 0.8 of the minimal edemal dose. Marked differences in skin carcinogenesis were observed between the p53+/- mice and their wild type littermates. Firstly, at 900 J/m2, tumors developed significantly faster in the heterozygotes than in wild types, whereas at 450 J/m2 there was hardly any difference, suggesting that only at higher damage levels loss of one functional p53 allele is important. Secondly, a large portion (25%) of skin tumors in the heterozygotes were of a more malignant, poorly differentiated variety of squamous cell carcinomas, i.e. spindle cell carcinomas, a tumor type that was rarely observed in daily UV exposed wild type hairless mice. Thirdly, the p53 mutation spectrum in skin tumors in heterozygotes is quite different from that in wild types. Together these results support the notion that a point mutation in the p53 gene impacts skin carcinogenesis quite differently than allelic loss: the former is generally selected for in early stages of skin tumors in wild type mice, whereas the latter enhances tumor development only at high exposure levels (where apoptosis becomes more prevalent) and appears to increase progression (to a higher grade of malignancy) of skin tumors.
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PMID:Dose-dependent effects of UVB-induced skin carcinogenesis in hairless p53 knockout mice. 1574 40

Fur condition in wild ringtailed lemurs, Lemur catta, was recorded during September-November birth seasons 2001-2006 at Berenty Reserve, Madagascar. Body coat condition was scored on a scale from BS 0: full, smooth coat with guard hairs, to BS5: half or more of back and limbs hairless. Tail condition was scored from TS 0: full, to TS 5: half or more hairless. Where troop core areas included stands of Leucaena leucocephala, alopecia was dramatically more frequent than in similar areas without leucaena, including many animals with score BS5 or TS5, "bald lemur syndrome." Females' coats were worse than males', possibly related to female dominance and access to this preferred food. Tails in non-leucaena-feeding females tend to remain full, even if coats deteriorate, but with leucaena-feeding female tails are highly correlated with coat condition and equally bare. Coat and tail condition in L. catta reflected not only the dietary toxin but individual differences as well as differences between adjacent troops that may result from territorially mediated access to the environment. Leucaena contains the non-protein amino acid mimosine, a known cause of alopecia, wasting, and organ damage in livestock, although the effects are usually reversible. This is the first case of its effect in wildlife. Leucaena is an agroforestry tree introduced throughout the tropics. In high dietary concentrations leucaena might potentially affect any browsing mammal.
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PMID:Coat condition of ringtailed lemurs, Lemur catta, at Berenty Reserve, Madagascar: II. Coat and tail alopecia associated with Leucaena leucocepahala, 2001-2006. 1905 14