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Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The plucked hairs and biopsied hair follicles of the scalp were obtained from a female patient with monilethrix. By scanning electron microscopy, the plucked hairs showed a typical moniliform feature composed of alternated nodes and internodes. By computer stereography, reconstructed three-dimensional models of in vivo hair structures showed that the diameter of hair shaft was partially reduced in the keratogenous zone and that the reduction was severe in the hair cortex and cuticle layers but mild in the inner root sheath. By transmission electron microscopy, a significant degeneration of hair matrix cells was found, and a zig-zag disarray of cortical tonofibrils and invaginations of the hair cuticle cells into the cortex were noticed in the suprabulbar portion. In some hairs, the hair bulbs showed no degeneration, but a degeneration of cortical cells and invaginations of hair cuticle were seen in some portions in the developing zone of the cortex. This suggests that not every hair matrix is damaged in a synchronized fashion, but individual hairs are affected independently. Furthermore, in all the hair and hair follicles examined, cytoplasmic vacuolations were always seen in the various layers, and abnormal formation of tonofibrils was often observed in the cortex. In monilethrix, a cell abnormality may inherently be present in the hair tissue and, when such abnormality occurs severely, the cortical cells are particularly affected in the hair matrix. This seems to result in a decrease in number of cortical cells and thinning of the hair shaft.
J Invest Dermatol 1990 Aug
PMID:Pathogenesis of monilethrix: computer stereography and electron microscopy. 238 May 77

Human adult keratinocytes migrating on a nonviable dermal substrate in cultures without fibroblasts induce thinning and degradation of the collagen substrate beneath the migrating epithelium. Further, unconcentrated conditioned medium from the cultures exhibit collagenolytic activity against both type I and type IV collagen which is inhibited by EDTA but not by phenylmethylsulfonyl fluoride or N-ethylmaleimide. Since the migrating epithelium and dermal substrate do not contain fibroblasts, this study shows that migratory keratinocytes in contact with interstitial collagen are capable of producing collagenases against type I and type IV collagen. Moreover, migratory keratinocytes appear to be similar to highly metastatic cells in their ability to degrade basement membrane collagen.
J Invest Dermatol 1986 Apr
PMID:Adult human keratinocytes migrating over nonviable dermal collagen produce collagenolytic enzymes that degrade type I and type IV collagen. 242 16

In investigations on Wistar rats aged 4-5 weeks it was found that intraperitoneal administration of Bleomycin in doses from 0.015 to 0.045 mg/100 g of body weight caused disturbances of hair growth. Initially hair loss had a telogenic mechanism, and after higher doses administered for longer time periods it changed to poorly evidenced alopecia with a dystrophic-telogenic pathological mechanism, without clinical signs of fur thinning.
Przegl Dermatol
PMID:[Studies on the effect of bleomycin on hair growth dynamics in rats]. 247 54

Etretinate is recognized to have unwanted cutaneous effects such as dryness of the skin, pruritus and hair thinning. Photosensitivity has rarely been observed as an adverse reaction but we now describe a renal transplant recipient who developed lesions of cutaneous porphyria apparently as a result of etretinate prescribed to suppress cutaneous neoplasia.
Clin Exp Dermatol 1989 Nov
PMID:Pseudoporphyria complicating etretinate therapy. 260 7

The effects of chronic hypervitaminosis A and long-term isotretinoin treatment on bone include cortical hyperostosis, ligament calcification and premature epiphyseal closure. Similar effects have now been reported in patients under maintenance treatment with etretinate in high doses. Etretinate, an oral, aromatic, synthetic vitamin A derivative, is widely used in Europe for disorders of keratinization. We report the cases of two patients--one with lamellar ichthyosis, the other with pachyonychia congenita--who developed such bone diseases during treatment with etretinate over 2 and 6 years respectively. The doses ranged from 0.5 to 1 mg/kg/day. Two years after starting treatment (total dose 25 g), the patient with lamellar ichthyosis complained of mechanical pain in the lumbar region and hips. Radiography showed calcification of the extraspinal tendons and ligaments and hyperostosis of the calcaneus bone at the insertion of the plantar ligament. After six years of etretinate treatment (total dose 50 g), the patient with pachyonychia congenita presented with scoliosis and limb length discrepancy. The musculoskeletal abnormalities resembled chronic hypervitaminosis A, with such osseous changes as demineralization, thinning and increased curvature of long bones with osteopenia, and premature closure of the epiphyses. Acroosteolysis was also present. Etretinate has been implicated in the formation of spinal hyperostoses and calcification of extraspinal ligaments in patients who had taken the drug for many years. The occurrence of premature epiphyseal closure in children certainly is a consequence of therapy with relatively high doses of etretinate for six years. But premature epiphyseal closure may also result from trauma to a fragile bone.(ABSTRACT TRUNCATED AT 250 WORDS)
Ann Dermatol Venereol 1989
PMID:[Rheumatologic effects of etretinate]. 266 Jul 11

The androchronogenetic alopecia (AGA) mouse if a mutant strain which expresses androgen-dependent baldness. Daily s.c. injection of testosterone (T) induced thinning of the hair coat along the upper dorsum after 4 weeks of treatment. After 12 to 14 weeks this diffuse alopecia eventually eveloped into a bald area which extended to the middorsum. Dihydrotestosterone was more effective than T in stimulating the onset of AGA. In this model, T produced the alopecia by decreasing the rate of hair growth, decreasing the duration of anagen, and markedly prolonging the duration of telogen. When applied topically at a concentration of 5%, cyproterone acetate delayed the progression of the T-mediated hair loss. However, this inhibitory effect occurred through systemic means as evidenced by decrease in the size of the submaxillary gland. Chronic feeding of androgen-treated female AGA mice with a diet containing 0.01% minoxidil also inhibited the development of alopecia. Skin and core temperatures were found to be higher in minoxidil-treated animals than in the placebo-treated controls. Minoxidil at a topical dose of 1% did not produce any effect. Increasing the dose to 2% caused a slight retardation of the development of alopecia. However, a 60% inhibition was observed at a topical dose of 5% minoxidil after 12 weeks of treatment (p less than 0.03). The data demonstrate that hair loss in the AGA mouse is androgen dependent and that this mutant strain can serve as a suitable model for the screening of compounds, such as antiandrogens and vasodilators, which may influence the balding process.
Arch Dermatol Res 1989
PMID:Animal models of androgen-dependent disorders of the pilosebaceous apparatus. 1. The androchronogenetic alopecia (AGA) mouse as a model for male-pattern baldness. 277 56

Despite an overall thinning of the epidermis and focal areas of cytologic atypia, there was no morphologic evidence that the protective function of this tissue was compromised by age. The characteristic morphologic markers associated with the keratinization process were not altered either in appearance or in amounts. A well-formed stratum corneum was present, suggestive that barrier ability is not compromised in senile skin. Whereas alterations in the aged epidermis are slight, the dermal-epidermal changes are marked and have greater physiologic consequences. The major change is a relatively flat dermal-epidermal junction because of retraction of the epidermal papillae as well as the microprojections of basal cells into the dermis. This flattening results in a more fragile tissue less resistant to shearing forces. Retraction of the epidermal downgrowths may also explain the loss in proliferative capacity associated with the aged epidermis. The major alterations in the aged dermis concern the architecture of the collagen and elastin networks. Both fibrous components appear more compact because of a decrease in the voids or spaces between the fibers; the spaces resulted from a loss of ground substance. Collagen bundles appear to unravel, and the individual elastic fibers show signs of elastolysis. The net effect of these fibrous rearrangements and alterations is a dermis that is less stretchable, less resilient, more lax, and prone to wrinkling.
Dermatol Clin 1986 Jul
PMID:Morphology of aged skin. 352 84

The fine structural organization of the epidermis, dermal/epidermal junction, and dermis from an unexposed site (upper inner arm) of elderly people was compared with the organization of a similar region of young people. Despite an overall thinning of the epidermis and focal areas of cytologic atypia, the characteristic morphological markers associated with the keratinization process are not markedly altered in appearance or amount. A well-formed stratum corneum consisting of flattened, enucleated horny cells enveloped by a thickened membrane, and intracellular spaces filled with electron-dense material provide structural evidence that barrier ability is not compromised in senile skin. The dermal/epidermal changes in aged skin are marked and have significant physiologic implications. The major change is a relatively flat dermal/epidermal junction resulting from the retraction of the epidermal papillae as well as the microprojections of basal cells into the dermis. This flattening results in a more fragile epidermal/dermal interface and, consequently, the epidermis is less resistant to shearing forces. Retraction of the epidermal downgrowths (preferential sites of the putative epidermal stem cell) may also explain the loss in proliferative capacity associated with the aged epidermis. The three-dimensional arrangements of collagen and elastic fibers showed marked alterations with age. Both fibrous components appear more compact because of a decrease in spaces between the fibers. Collagen bundles appear to unravel, and the individual elastic fibers show signs of elastosis. These changes may contribute to the loss of resilience that is one of the salient features of senile skin.
J Invest Dermatol 1987 Mar
PMID:Aged skin: a study by light, transmission electron, and scanning electron microscopy. 354 15

We report a family of six individuals with an abnormality of scalp hair characterized by shorter, finer, kinky hairs interspersed with normal hair, throughout the scalp. The abnormality had gone unnoticed in four of the six individuals. Two complained of thinning of the scalp hair.
Br J Dermatol 1987 Mar
PMID:A family with diffuse partial woolly hair. 356 76

Ophthalmological lesions enter in the definition of Cogan's syndrome, associated with vestibulo-auditory symptoms. They are present in almost one half of patients with Wegener's granulomatosis and in 10 to 20 p. 100 of patients with periarteritis nodosa, where they may be the initial symptom. Yet they are seldom described in leucocytoclastic angiitis of small vessels, 3 cases of which are reported here. The first case concerns a 71-year old woman with cutaneous leucocytoclastic angiitis which regressed within a few days under dapsone. However, the drug had to be withdrawn on account of acute haemolysis. Thereafter, new skin lesions and severe pain in the left eye with fall in visual acuity developed simultaneously. Eye examination showed a large, marginal ulceration of the cornea extending to the adjacent sclera and reflecting deep involvement of the sclerocorneal limbus. Systemic corticosteroid therapy in doses of 1 mg/kg/day was instituted, resulting in gradual disappearance of the skin lesions and stabilization of the ophthalmic lesion. There remains, however, thinning of the cornea and sclera which entails a definite risk of perforation should the angiitis recur. The second patient was a 54-year old man seen for fever, polyarthralgia, purpura of the lower limbs and rapidly extending necrotic ulceration of the scrotum. A few days previously, inflammatory chemosis of the right eye had suddenly developed. Under systemic corticosteroids (1.5 mg/kg/day), the ophthalmic symptoms rapidly regressed, but the patient died of digestive tract haemorrhage. The third case was that of a 36-year old woman with urticaria associated with arthralgias and diffuse myalgia.(ABSTRACT TRUNCATED AT 250 WORDS)
Ann Dermatol Venereol 1986
PMID:[Ophthalmologic manifestations of leukocytoclastic vasculitis. Apropos of 3 case reports]. 357 12


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