Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 45-year-old premenopausal woman presented with an 18-month history of a band-like area of fibrosing alopecia affecting the frontoparietal scalp. She also had marked thinning of the eyebrows. The histopathology was consistent with frontal fibrosing alopecia (FFA). Several months later she developed multiple pruritic papules on the wrists and feet. The clinical presentation and histopathology were consistent with cutaneous lichen planus. Although FFA has been reported to occur with mucosal lichen planus this is the first reported case of FFA associated with cutaneous lichen planus. This provides further evidence that FFA is a variant of lichen planopilaris.
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PMID:Frontal fibrosing alopecia associated with cutaneous lichen planus in a premenopausal woman. 1186 13

This study reports UV screening pigments in the upper cortices of two widespread lichens collected in three sun-exposed locations along a latitudinal gradient from the Arctic lowland to alpine sites of the Central European Alps. Populations from the Alps receive 3-5 times higher UV-B irradiance than their Arctic counterparts from Svalbard because of latitudinal and altitudinal gradients in UV-B irradiance. In Cetraria islandica, the screening capacity of melanin in the upper cortices was assessed by direct measurements of cortical transmittance (250-1,000 nm). A comparison of cortical transmittances in brown sun-exposed and pale shade-adapted forest C. islandica thalli showed that fungal melanins strongly absorb both UV-B and photosynthetically active radiation (PAR). For Xanthoria elegans cortical UV-B absorbing pigments, mainly the orange parietin, were extracted and quantified. Field experiments with extracted, parietin-deficient X. elegans thalli cultivated under various filters showed that UV-B was essential for the induction of parietin synthesis. The parietin resynthesis in these parietin-deficient samples increased with decreasing latitude of their location in which they had been sampled, which may imply that the synthesis of pigments is habitat specific. However, no latitudinal gradient in cortical screening capacity was detected for any of the two species investigated in the field. This implies that Arctic populations maintain a high level of screening pigments in spite of low ambient UV-B, and that the studied lichen species presumably may tolerate an increase in UV-B radiation due to the predicted thinning of the ozone layer over polar areas.
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PMID:The lichens Xanthoria elegans and Cetraria islandica maintain a high protection against UV-B radiation in Arctic habitats. 1513 81

Lichen nitidus is a rare chronic condition of unknown etiology. Generalized lichen nitidus is even rarer. We report here a 5-year-old girl who had multiple, asymptomatic, discrete, 1 to 2 mm flesh-colored, shiny, flat, papules on her face, upper limbs, and thighs with relative sparing of the trunk. Resolution of these papular lesions was followed by hyperpigmented macules in those areas. Histopathologic examination of a papular lesion revealed a localized granulomatous lymphohistiocytic infiltrate in an expanded dermal papilla with thinning of overlying epidermis and downward extension of the rete ridges at the lateral margin of the infiltrate, producing a typical "claw clutching a ball" picture, confirming our clinical diagnosis of lichen nitidus. The pigmented macules showed melanin pigmentation on histology. There was no response to oral astemizole treatment for 3 months. However, the lichen nitidus lesions resolved spontaneously without any further treatment over the next year, leaving behind a prominent pigmentary disturbance.
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PMID:Generalized lichen nitidus. 1580 8

We studied northern flying squirrel (Glaucomys sabrinus) demography in the eastern Washington Cascade Range to test hypotheses about regional and local abundance patterns and to inform managers of the possible effects of fire and fuels management on flying squirrels. We quantified habitat characteristics and squirrel density, population trends, and demography in three typical forest cover types over a four-year period. We had 2034 captures of flying squirrels over 41 000 trap nights from 1997 through 2000 and marked 879 squirrels for mark-recapture population analysis. Ponderosa pine (Pinus ponderosa) forest appeared to be poorer habitat for flying squirrels than young or mature mixed-conifer forest. About 35% fewer individuals were captured in open pine forest than in dry mixed-conifer Douglas-fir (Pseudotsuga menziesii) and grand fir (Abies grandis) forests. Home ranges were 85% larger in pine forest (4.6 ha) than in mixed-conifer forests (2.5 ha). Similarly, population density (Huggins estimator) in ponderosa pine forest was half (1.1 squirrels/ha) that of mixed-conifer forest (2.2 squirrels/ha). Tree canopy cover was the single best correlate of squirrel density (r = 0.77), with an apparent threshold of 55% canopy cover separating stands with low- from high-density populations. Pradel estimates of annual recruitment were lower in open pine (0.28) than in young (0.35) and mature (0.37) forest. High recruitment was most strongly associated with high understory plant species richness and truffle biomass. Annual survival rates ranged from 45% to 59% and did not vary among cover types. Survival was most strongly associated with understory species richness and forage lichen biomass. Maximum snow depth had a strong negative effect on survival. Rate of per capita increase showed a density-dependent response. Thinning and prescribed burning in ponderosa pine and dry mixed conifer forests to restore stable fire regimes and forest structure might reduce flying squirrel densities at stand levels by reducing forest canopy, woody debris, and the diversity or biomass of understory plants, truffles, and lichens. Those impacts might be ameliorated by patchy harvesting and the retention of large trees, woody debris, and mistletoe brooms. Negative stand-level impacts would be traded for increased resistance and resilience of dry-forest landscapes to now-common, large-scale stand replacement fires.
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PMID:Demography of northern flying squirrels informs ecosystem management of western interior forests. 1671 Oct 46

Will old-growth-associated epiphytes survive if the forest canopy is opened around them by thinning or partial harvest? If old-growth association is due to a species' environmental tolerances, it may not survive in the relatively open stands that result from such treatments. If, however, old-growth association is due to dispersal limitations rather than environmental tolerances, retention of host trees as refugia and sources of inoculum might carry populations of old-growth-associated epiphytes into young stands. We studied growth rates of lichen and moss transplants in a Douglas-fir (Pseudotsuga menziesii) forest (tree ages approximately 55 yr) in western Oregon for nine months before and 27 months after moderate thinning, creation of 0.4-ha patch cuts, and in control areas. We also assessed moss sporophyte production. We contrasted responses of one moss species, Isothecium myosuroides sensu lato, which is ubiquitous in forests of varying ages, with those of another moss, Antitrichia curtipendula, and a lichen, Lobaria oregana, which are both associated with old-growth forests. Both old-growth associates grew faster in thinned areas and patch cuts than in controls, while Isothecuim grew most slowly and produced fewest sporophytes in patch cuts. These species are likely to survive in remnants, assuming they can remain attached, and may be successful in young stands if they can disperse and establish there. Our results suggest that logging with green-tree retention and other silvicultural practices that preserve trees or shrubs hosting the species studied here are likely to encourage these species' development in managed forests.
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PMID:Influence of overstory removal on growth of epiphytic mosses and lichens in western Oregon. 1682 13

Lichen striatus (LS) is a relatively rare and self-limited linear dermatosis of unknown etiology. It primarily affects children, with more than 50% of cases occurring in patients aged 5 to 15 years. The case of a 2-year-old boy who presented for evaluation of a nonpruritic linear rash on the left side of the lower abdomen of 3 weeks' duration is discussed. A diagnosis of lichen striatus (LS) was made and the lesions completely resolved within 6 months. At 5 years of age, the patient returned for evaluation of bluish discoloration and thinning of the nails on the left middle and ring fingers, which ultimately fell off and started to regrow 2 months prior to the second evaluation. The rare diagnosis of isolated onychodystrophy as a late manifestation of LS was made.
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PMID:Bilateral onychodystrophy in a boy with a history of isolated lichen striatus. 2547 62