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)

Hair loss or hair thinning is a common complaint in clinical dermatology, and patients seeking advice for hair loss are not necessarily bald. Because the effects of treatment attempts are hard to measure, there is need for a sensitive tool to monitor hair loss and treatment responses. Such a method must be able to analyze the biologic parameters of hair growth, which are: (i) hair density (n per cm2); (ii) hair diameter (microm); (iii) hair growth rate (mm per day); and (iv) anagen/telogen ratio. Herein we present the TrichoScan as a method that combines epiluminescence microscopy with automatic digital image analysis for the measurement of human, and potentially animal hair, in situ. The TrichoScan is able to analyze all four parameters of hair growth with a so-called intraclass correlation of approximately 91% within the same TrichoScan operator and an intraclass correlation of approximately 97% for different TrichoScan operators. The application of the technique is demonstrated by comparing the hair parameters in individuals without apparent hair loss, men with untreated androgenetic alopecia, and men after treatment with finasteride (1 mg per day). We were able to detect a significant increase in hair counts and cumulative hair thickness 3 and 6 mo after treatment. Advantages of the TrichoScan are that it can be used for clinical studies to compare placebo versus treatment, to compare different capacities of hair growth promoting substances, to study androgenetic alopecia and other forms of diffuse hair loss, and to study the effects of drugs and laser treatment on hypertrichosis and hirsutism.
J Investig Dermatol Symp Proc 2003 Jun
PMID:TrichoScan: a novel tool for the analysis of hair growth in vivo. 1289 6

The biological importance and/or significance of human hair colour is unknown even though greying is obviously associated with ageing. In order to further characterise hair pigmentation in relation with hair growth variables we evaluated 3 scalp sites (top of the head (T): left and right and occipital(O)) in 12 untreated menopausal women (age range: 49-66 years: average 59.63 +/- 5.66) who presented complaining of hair loss and/or diffuse alopecia. Controls were 12 non menopausal sexually mature woman (7 age range 15-21 and 5 age range 38-48) not complaining of hair loss. One hair sample (whenever possible n = 60) was taken one month after clipping from T and O on each person; menopausal women were sampled twice. The following measures were performed with a light microscope: diameter (average min-max., microm), medulla (0% = absent to 100% = fully developed) and linear hair growth rate (mm/day). The hairs were categorised as pigmented (P) or non-pigmented (white, W) as compared with a black and white reference card. A total of 3343 hairs were analysed with 2-factor analysis of variance (ANOVA). A global comparison (all hairs) showed that the average diameter of W hair (67.68 microm) exceeded that of P hair (57.41 microm) (p = 0.0001) and this was maintained on all 3 scalp sites. In addition, the medulla of W hair (23.91%) appeared more developed than the medulla of P hair (12.21%) (p = 0.0001) and was more expressed in W T hairs as compared with W O hairs (p = 0.0325). There was also a significant interaction between site and pigmentation (p = 0.0074). Growth rate of W hairs (0.38 mm/d) was higher than that of P hairs (0.35 mm/d) (p = 0.0001) and there was a significant variation according to scalp sites (p = 0.0001). There was also a significant interaction between site and pigmentation (p = 0.0062) with the following rank order: O W (0.40 mm/d), T W (0.37 mm/d), O P (0.37 mm/d) and T P (0.34 mm/d). Subgroups of W and P of paired thickness in the range of 50 to 80 pm consistently showed a 10% faster growth rate of W. Previous studies have shown that growth rate and diameter declines in age and alopecia i.e. in hair thinning. Our data shows that the reduced growth rate of terminal hairs is in fact limited to the pigmented hairs. The mechanisms by which white hairs are spared these ageing changes are not yet understood. Less pigmented hairs are usually undetected by photo- graphic techniques used for drug trials. The potential role of drug induced modifications of hair pigmentation should be taken into account during the interpretation of efficacy except if contrast-enhancement has been applied.
Eur J Dermatol
PMID:Thickness, medullation and growth rate of female scalp hair are subject to significant variation according to pigmentation and scalp location during ageing. 1496 92

A 3-month open-label pilot study was carried out to assess the safety, tolerability, and effect of the antiepilectic topiramate on the cosmetic appearance of scars. Ten adult subjects with discolored or raised scars at least 2 years old were given an oral dosage of 15 mg per day of topiramate for 1 month. The dosage was then increased to 30 mg per day if there was minimal or no improvement. The safety of topiramate was assessed in this study by reviewing adverse events and vital signs. Efficacy outcomes included a Clinician Global Impression Scale (CGI) to document changes such as thickness and color. Digital photos were taken with consistent variables. In addition, two independent medical reviewers blindly reviewed the photos. The Rosenberg Self-Esteem Scale was done at each visit to measure patients' levels of self-esteem. Side effects were generally mild with the most common being language problems (n = 3) and sleep disturbances (n = 3). All subjects completed the study and experienced at least minimal thinning and decreased coloration (usually redness) of their scars. Based on CGI-assessment data at 3 months, two subjects were very much improved, four were much improved, and four had minimal improvement. One independent medical reviewer arranged before and after treatment picture sets for ten out of ten subjects. The other independent medical reviewer arranged before and after treatment pictures sets for nine out of ten subjects (both p-values less than 0.025). The data indicate that topiramate may be a safe and effective treatment for scar therapy.
Dermatol Online J 2003 Dec
PMID:Evaluation of open-label topiramate for scar therapy. 1640 38

Estrogen is reported to prevent age-associated epidermal thinning in the skin. We examined if 17beta-estradiol (E2) may enhance the growth of human keratinocytes, focusing on its effects on the expression of cell cycle-regulatory proteins. E2 enhanced proliferation, bromodeoxyuridine incorporation of keratinocytes, and increased the proportion of cells in the S phase. The E2-induced stimulation of proliferation and bromodeoxyuridine incorporation was suppressed by antisense oligonucleotide against cyclin D2, which induces G1 to S phase progression. E2 increased protein and mRNA levels of cyclin D2, and resultantly enhanced assembly and kinase activities of cyclin D2-cyclin-dependent kinases 4 or 6 complexes. E2 enhanced cyclin D2 promoter activity, and the element homologous to cAMP response element (CRE) on the promoter was responsible for the effect. Cyclin D2 expression was enhanced by antiestrogens, ICI 182,780 and 4-hydroxytamoxifen, and membrane-impermeable bovine serum albumin-conjugated E2, indicating the effects via membrane E2-binding sites. E2 increased the enhancer activity of CRE-like element and the amount of phosphorylated cAMP response element binding protein (CREB) binding this element, and the increases were suppressed by H-89, an inhibitor of cAMP-dependent protein kinase A. H-89 also suppressed E2-induced cyclin D2 expression, proliferation, and bromodeoxyuridine incorporation in keratinocytes. Antisense oligonucleotide against G-protein-coupled receptor GPR30 suppressed the E2-induced increases of phosphorylated CREB, cyclin D2 level, proliferation, and bromodeoxyuridine incorporation in keratinocytes. These results suggest that E2 may stimulate the growth of keratinocytes by inducing cyclin D2 expression via CREB phosphorylation by protein kinase A, dependent on cAMP. These effects of E2 may be mediated via cell surface GPR30.
J Invest Dermatol 2004 Aug
PMID:17beta-estradiol stimulates the growth of human keratinocytes by inducing cyclin D2 expression. 1524 32

Atrophic dermatofibroma, a newly proposed entity in recent times, is thought to be a specific variant of dermatofibroma. We report a typical case of atrophic dermatofibroma on the thigh of a 69-year-old female. The lesion consisted clinically of a light brown, intracutaneous nodule with a central crateriform depression, and histologically of fibrohistiocytic components in the thinning dermis. On elastica van Gieson stain, loss of elastic fibres and dense accumulation of elastic fibres around medium-sized vessels were observed in the lesion.
J Eur Acad Dermatol Venereol 2004 Sep
PMID:Atrophic dermatofibroma. 1532 99

Androgenetic alopecia (AGA) is the most common type of hair loss in adults. Although there are differences in the age at onset, the disease starts after puberty when enough testosterone is available to be transformed into dihydrotestosterone. We report 20 prepubertal children with AGA, 12 girls and eight boys, age range 6-10 years, observed over the last 4 years. All had normal physical development. Clinical examination showed hair loss with thinning and widening of the central parting of the scalp, both in boys and girls. In eight cases frontal accentuation and breach of frontal hairline were also present. The clinical diagnosis was confirmed by pull test, trichogram and dermoscopy in all cases, and by scalp biopsy performed in six cases. There was a strong family history of AGA in all patients. The onset of AGA is not expected to be seen in prepubertal patients without abnormal androgen levels. A common feature observed in our series of children with AGA was a strong genetic predisposition to the disease. Although the pathogenesis remains speculative, endocrine evaluation and a strict follow-up are strongly recommended.
Br J Dermatol 2005 Mar
PMID:Androgenetic alopecia in children: report of 20 cases. 1578 28

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.
Pediatr Dermatol
PMID:Generalized lichen nitidus. 1580 8

There are conflicting reports of the consequences of deleting beta1 integrins from the epidermis of transgenic mice. Epidermal thinning with normal differentiation and lack of inflammation has been observed; conversely, epidermal thickening, abnormal differentiation, and dermal fibrosis can occur. beta1 integrin deletion results in decreased epidermal proliferation, yet on wounding the proliferative defect is overcome. To distinguish primary from secondary consequences of beta1 integrin loss, we compared epidermal beta1 deletion at E14.5 via K5Cre and 4-hydroxy-tamoxifen induced deletion in adulthood via K14CreER. As reported previously, there was dermo-epidermal splitting, inflammation, reduced proliferation, and hair follicle and sebaceous gland loss in 30-d-old K5Cre beta1-null mice. These changes were not observed 30 d after beta1 integrin deletion in adult epidermis, however, and there were no changes in the hair follicle stem cell compartment. Deletion in adult epidermis revealed a previously unreported correlation between the level of beta1 integrins and proliferation in the interfollicular epidermis that was remarkably consistent with human epidermis. In addition, the number of melanocytes in interfollicular epidermis was greatly increased. Our results highlight the context-dependent effects of beta1 integrin deletion and suggest that inflammation may be responsible for some of the K5Cre beta1-null phenotype.
J Invest Dermatol 2005 Dec
PMID:Different consequences of beta1 integrin deletion in neonatal and adult mouse epidermis reveal a context-dependent role of integrins in regulating proliferation, differentiation, and intercellular communication. 1635 92

Sensitive tools have been developed in order to monitor hair loss and treatment responses. Recently the Tricho-Scan was presented (by RH) as such a method which combines epiluminescence microscopy (ELM) with automatic digital image analysis. Herewith new TrichoScan data obtained from 10 women and 21 men with androgenetic hair loss after 6 mo of treatment with 5%-minoxidil are presented. Even in this small cohort of patients, we noticed a significant increase of hair density, cumulative hair thickness and terminal hair counts. Alternative methods were developed during a human alopecia investigation and research technology (HAIR Technology) programme at Skinterface. This involves contrast-enhancement, image acquisition, and processing by qualified technicians followed by computer-assisted image analysis. The specific identification of exogen hair, further adds to this very refined non-invasive investigative method for hair follicle function investigation. Regional variations of hair growth dynamics do exist in the human scalp such as in female patients complaining of hair loss, scalp hair density and growth on top of the head differs significantly from the occipital site. Finally, from transversal studies and from detailed monitoring of subsequent hair cycles during longitudinal studies, data were obtained that support the fact that shortening of hair cycle, slowing down of growth rates and thinning of hair shafts are heralding hair miniaturisation. In the workshop the TrichoScan, the method of Canfield and Skinterface have been shown.
J Investig Dermatol Symp Proc 2005 Dec
PMID:Recent findings with computerized methods for scalp hair growth measurements. 1638 82

Overexpression of PPAR-alpha, a developmental transcription factor important in epidermal embryogenesis, in basal keratinocytes causes epidermal thinning when activated constitutively during development, but not if activated in adults; and lack of PPAR-alpha transiently delays stratum corneum formation within a window late in epidermal development (day 18.5 to birth). In contrast, pharmacologic activation of PPAR-alpha inhibits proliferation and induces differentiation in mouse epidermis regardless of developmental stage. Thus, PPAR-alpha is an important regulator of epidermal homeostasis.
J Invest Dermatol 2006 Feb
PMID:(P)PARsing epidermal development. 1637 67


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