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  • cutaneous
  • In lichen striatus, an acquired event (eg, viral infection) may allow an aberrant clone of cutaneous cells to express a new antigen, resulting in the phenotypic skin changes. (medscape.com)
  • thalli
  • Lichens do not have a waxy cuticle like plants have on their leaves, nor do they have vascular tissue such as xylem and phloem to move nutrients and water around their thalli as a plant does. (fed.us)
  • Foliose lichens are large and leafy, reaching diameters of several feet in some species, and are usually attached to the substrate by their large platelike thalli at the centre. (britannica.com)
  • In addition to their morphological forms, lichen thalli are also classified by the ratio of phycobiont cells (i.e., cells of the photosynthetic partner) to mycobiont cells (i.e., cells of the fungus). (britannica.com)
  • The thalli produced by a given fungal symbiont with its differing partners will be similar, and the secondary metabolites identical, indicating that the fungus has the dominant role in determining the morphology of the lichen. (wikipedia.org)
  • cortex
  • When a lichen is dry, its color is usually gray or colored like the fungal cells on the upper cortex. (fed.us)
  • Although lichens had been assumed to consist of a single fungus species (usually an ascomycete ) and a single photosynthetic partner, research suggests that many macrolichens also feature specific basidiomycete yeasts in the cortex of the organism. (britannica.com)
  • Lichens also sometimes contain structures made from fungal metabolites, for example crustose lichens sometimes have a polysaccharide layer in the cortex. (wikipedia.org)
  • The internal structure of fruticose lichen is composed of a dense outer cortex, a thin algal layer, a medulla and a hollow center or a dense central cord. (wikipedia.org)
  • The morphological characters employed to distinguish species of Niebla include the orientation of ridges in the lichen cortex, differences in fragmentation branchlets, which often have black carbonized pycnidia, and the development of specialized asexual propagules referred to as soredia and isidia. (wikipedia.org)
  • sclerosus
  • Lichen sclerosus et atrophicus (LSA) is a chronic skin disease characterized by white, flat papules with an erythematous halo and black, hard follicular plugs. (healthcentral.com)
  • Is it lichen sclerosus? (healthcentral.com)
  • Lichen sclerosus (LS) is a skin disease of unknown cause, commonly appearing as whitish patches on the genitals, which can affect any body part of any person but has a strong preference for the genitals (penis, vulva) and is also known as balanitis xerotica obliterans (BXO) when it affects the penis. (wikipedia.org)
  • Lichen sclerosus is not contagious. (wikipedia.org)
  • Distress due to the discomfort and pain of Lichen Sclerosus is normal, as are concerns with self-esteem and sex. (wikipedia.org)
  • According to the National Vulvodynia Association, which also supports women with Lichen Sclerosus, vulvo-vaginal conditions can cause feelings of isolation, hopelessness, low self-image, and much more. (wikipedia.org)
  • Lichen sclerosus may have a genetic component. (wikipedia.org)
  • Higher rates of lichen sclerosus have been reported among twins and among family members. (wikipedia.org)
  • Topically applied corticosteroids to the LS-affected skin are the first-line treatment for lichen sclerosus in women and men, with strong evidence showing that they are "safe and effective" when appropriately applied, even over long courses of treatment, rarely causing serious adverse effects. (wikipedia.org)
  • symbionts
  • A lichen is an association between one or two fungus species and an alga or cyanobacterium (blue-green alga) that results in a form distinct from the symbionts. (britannica.com)
  • In such cases, heterocyst differentiation was greater in cephalodia when compared to having Nostoc as the primary symbionts in lichens, showing that, in the presence of non N2-fixing phototroph, Nostoc specialize for N2 fixation. (wikipedia.org)
  • photobiont
  • The photosynthetic component of a lichen is called the photobiont or phycobiont. (wikipedia.org)
  • However, for lichens that cannot increase their photobiont growth, nitrogen deposition can be damaging due to higher nitrogen concentration than their biological requirements. (wikipedia.org)
  • Although the form of a lichen is determined by the genetic material of the fungal partner, association with a photobiont is required for the development of that form. (wikipedia.org)
  • When grown in the laboratory in the absence of its photobiont, a lichen fungus develops as an undifferentiated mass of hyphae. (wikipedia.org)
  • The photobiont once in symbionce with its fungal partner will not produce recognisable reproductive structures therefore it is up to the fungal partner to continue reproduction for the lichen. (wikipedia.org)
  • In order for lichen reproduction to take place the fungal partner must produce millions of germinating spores which fuse to form a zygote that must then also find a compatible photobiont. (wikipedia.org)
  • This photobiont will fuse with the zygote and live within the fungi creating a lichen. (wikipedia.org)
  • morphology
  • Salazinic acid is a common lichen substance accessory to triterpenes in species of Vermilacinia, while it may also be noted that the morphology of V. laevigata is easily confused with that of N. homalea. (wikipedia.org)
  • Niebla has 42 species distinguished by secondary metabolites (lichen substances) and by morphology. (wikipedia.org)
  • specimens
  • Support of infectious involvement includes elevations of interleukin 1-beta in lichen striatus biopsy specimens. (medscape.com)
  • It was discovered in December 1934 by the Byrd Antarctic Expedition sledge party under Paul Siple, and so named because of the lichens and other botanical specimens obtained there. (wikipedia.org)
  • amyloidosis
  • I have lichen amyloidosis. (dailystrength.org)
  • http://dermnetnz.org/systemic/amyloidosis.html above is a link to copy and put in your browser that will help to explain lichen amyloidosis. (dailystrength.org)
  • The article specifically mentions lichen amyloidosis, and that the disease itself is caused by scratching. (dailystrength.org)
  • Lichen amyloidosis is believed to be more prevalent among Southern Chinese and South American populations. (medscape.com)
  • Lichen amyloidosis accounts for approximately 10% of cases of PLCA. (medscape.com)
  • The lichen amyloidosis in this syndrome is usually localized to the interscapular region consisting of lichenoid papules, with hyperpigmentation and fine scaling. (medscape.com)
  • The histopathologic and immunohistochemistry findings are similar to those in isolated lichen amyloidosis, pointing to keratin-derived amyloidosis. (medscape.com)
  • Maddison et al suggest a possible cause of the severe pruritus associated with lichen amyloidosis in relation to nerve fiber density. (medscape.com)
  • Lichen amyloidosis is a chronic condition without potential for malignant transformation or increase in mortality. (medscape.com)
  • Amyloid deposits in macular amyloidosis and lichen amyloidosis bind to antikeratin antibodies. (medscape.com)
  • Apaydin et al found no differences in staining characteristics of cytokeratins between macular amyloidosis and lichen amyloidosis. (medscape.com)
  • Weyers et al presented a convincing argument that the deposition of amyloid in lichen amyloidosis is not the cause but the result of itching and scratching. (medscape.com)
  • occurs
  • When this reaction occurs in plants the lichen will then have less chlorophyll causing a decrease in respiration which eventually kills the lichen (Hill 831-836). (wikipedia.org)
  • eruption
  • A case of lichen striatus has been reported during pregnancy, and it has been postulated that the pregnancy may have triggered an autoimmune response leading to the appearance of the eruption. (medscape.com)
  • The concurrent lichen striatus eruption may have manifested after being triggered by this viral infection. (medscape.com)
  • medulla
  • They open into the medulla of the lichen, and have specialized cells lining the floor of the pore that distinguish them from pseudocyphellae, which are similar structures but lack such specialized cells. (wikipedia.org)
  • water and nutrients
  • Lichens get their water and nutrients from their surrounding environment via air and rain. (fed.us)
  • Lichens do not have roots that absorb water and nutrients as plants do, but like plants, they produce their own food by photosynthesis. (wikipedia.org)
  • benign
  • Lichen striatus is a rare, benign, self-limited linear dermatosis of unknown origin that predominantly affects children. (medscape.com)
  • papular
  • The terms lichen myxedematosus, papular mucinosis, and scleromyxedema are used interchangeably to describe the same disorder. (medscape.com)
  • A spectrum of disease appears to exist, with the more localized, less severe forms, which are generally called lichen myxedematosus or papular mucinosis, and the more sclerotic, diffuse form, which is referred to as scleromyxedema. (medscape.com)
  • absent
  • Sclerotic features, systemic involvement, and monoclonal gammopathy are absent in localized lichen myxedematosus. (medscape.com)
  • moss
  • It was the same rich green that one sees on forest moss or on the lichen in caves: plants which like these grow in a perpetual twilight. (wiktionary.org)
  • It is sometimes confused with the plant known as Spanish moss , which is similar in appearance but is unrelated to lichens. (britannica.com)
  • Common names for lichens may contain the word "moss" (e.g., "reindeer moss", "Iceland moss"), and lichens may superficially look like and grow with mosses, but lichens are not related to mosses or any plant. (wikipedia.org)
  • Several different English names have been recently invented for wila, including black moss, black tree lichen, and edible horsehair lichen, but none of these names are in common usage. (wikipedia.org)
  • lichen's
  • Lichen's characteristic, such as strong resistances to factors such as desiccation, ability to grow and breakdown rocks allow lichen to grow in different types of environment including highly nitrogen limited area such as subarctic health. (wikipedia.org)