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Biomedical subjects

T Stoudemayer

Publications and source records attributed to T Stoudemayer.

10 recordsLinked to original sources
PubMed2001

Corticosteroid-induced atrophy and barrier impairment measured by non-invasive methods in human skin.

BACKGROUND/AIMS: Atrophy is a distressing side effect of potent corticosteroids. After open application of a high potency steroid, we monitored atrophogenicity by a variety of non-invasive methods. METHODS: Volar forearms were treated twice daily for 3 or 4 weeks, with clobetasol propionate cream (Temovate). The following methods were used: 1) confocal microscopy, 2) transepidermal water loss (TEWL), 3) dimethyl sulfoxide whealing, 4) sodium hydroxide erosions, 5) analysis of stratum corneum lipids, and 6) B-scan ultrasound. RESULTS: Confocal microscopy revealed thinning of the epidermis, decreased microvasculature and decreased size of keratinocytes. Evaporimetry demonstrated transepidermal water loss. Whealing to dimethyl sulfoxide was enhanced. Sodium hydroxide erosions formed more quickly. The amount of ceramides, cholesterol, and free fatty acids was reduced. Ultrasound showed thinning of the dermis. CONCLUSION: Non-invasive methods are very useful for quantifying the atrophogenicity of topical corticosteroids.

Administration, Topical↗
PubMed2001

Polarized light photography and videomicroscopy greatly enhance the capability of estimating the therapeuic response to a topical retinoid (adapalene) in acne vulgaris.

Assessment of improvement in acne lesions following treatment is often based on clinical evaluation and photographs. However, limitations are associated with this sublective evaluation, making it difficult to accurately review individual acne lesions and to observe early response to therapy. Conventional photographs do not allow us to visualize small lesions, and it can be difficult to differentiate inflammatory lesions as papules or small nodules. Our objective was to evaluate a new standardized method for tracking individual acne lesions based on photographs. The effect of adapalene gel 0.1% on both inflammatory and noninflammatory acne lesions was evaluated using this technique. Polarized light photography and videomicroscopy were used to record the evolution of acne lesions over a 16-week period in 5 volunteers with moderate acne vulgaris. During the first 4 weeks before treatment, acne lesions were evaluated on a 3-times weekly basis to establish a pattern of progression and determine the length of time to resolution. Sebum secretion rates were monitored using Sebutape adhesive patches applied to the forehead and both cheeks for 1 hour. After 4 weeks, adapalene gel 0.1% was used once daily at bedtime for 8 weeks; polarized light photography, videomicroscopy, and assessment of sebum production followed treatment response. This treatment period was followed by a further 4-week phase, after which acne lesions and sebum secretion rates were evaluated. Our results showed that the new methodology was appropriate to track acne lesions and allowed an accurate and more oblective evaluation of individual lesions. Using this methodology demonstrated that adapalene gel 0.1% causes rapid resolution of inflammatory and noninflammatory lesions. The probability of clearing inflammatory and noninflamma tory lesions during the treatment period increased, and the probability of new lesions appearing decreased. Sebum secretion rates declined in patients while on study drug, returning to near pretreatment levels following therapy cessation. Using sophisticated photography and videomicroscopy every other day proved to be a valuable, noninvasive, and reliable method of following response to adapalene treatment in patients with moderate acne vulgaris.

Acne Vulgaris↗
PubMed1999

Digital fluorescence photography can assess the suppressive effect of benzoyl peroxide on Propionibacterium acnes.

BACKGROUND: Porphyrins produced by Propionibacterium acnes exhibit an orange-red fluorescence under UVA light. The amount of fluorescence can be estimated by digital fluorescence photography. OBJECTIVE: We thought that digital fluorescence photography would be a quicker and simpler method than bacteriologic culture to demonstrate depopulation of P acnes in sebaceous follicles. We used benzoyl peroxide to bring about rapid suppression of P acnes. METHODS: Benzoyl peroxide 10% was applied twice daily for 7 days to the faces of 9 subjects. Five subjects were untreated controls. Digital fluorescence photographs of cheek and nose, and scrub samples for quantitative recovery of P acnes from the cheek were taken at baseline, day 3, day 7 (end of treatment), and day 16 (regression phase). RESULTS: The effect of benzoyl peroxide against P acnes was clearly demonstrated both by culture and by fluorescence photography after only 3 days. Image analysis of porphyrin fluorescence correlated well with the decrease in P acnes density from scrub cultures. No further decrease was observed at day 7 (end of therapy). Ten days later there was a return to baseline values, although in some subjects these remained lower. CONCLUSION: Digital fluorescence photography is a reliable, fast, and easy screening technique to demonstrate the suppressive effect of topical antibacterial agents on P acnes.

Adolescent↗
PubMed1999

Quantitative and ultrastructural analysis of inflammatory infiltrates in male pattern alopecia.

In order to determine whether lymphocytic inflammation around the lower infundibula in male pattern alopecia is incidental or a general phenomenon, we performed morphometric and ultrastructural analysis of inflammatory infiltrates in the transitional zones of the vertex and occipital hairy scalps of 19 patients with male pattern alopecia. Six normal subjects served as controls. The number of inflammatory infiltrates around the follicular infundibula of the alopecic vertices and non-alopecic occiputs of male pattern alopecia patients was significantly greater than the corresponding control value. The number of mast cells in the widened fibrous tracts in the vertices of male pattern alopecia patients was significantly greater than those in the adventitial fibrotic sheaths of control subjects and the non-alopecic occiputs of male pattern alopecia patients. These data support the idea that the inflammatory process may be, at least in part, responsible for the development of male pattern alopecia.

Adolescent↗
PubMed1999

Hypopigmented macules of photodamaged skin and their treatment with topical tretinoin.

Hypopigmented macules are frequently observed in the photodamaged skin of elderly people. We undertook to study and treat 2 types of hypomelanosis of photoaged skin. These lesions were: 1) idiopathic guttate hypomelanosis; and 2) macular hypomelanosis. Comparative studies included: 1) high-resolution photography using parallel polarized light, ultra-violet (UVA) and epiluminescence; 2) Silflo replicas for microtopography; and 3) suction device (Cutometer) for elasticity. Macular hypomelanosis was distinguishable from idiopathic guttate hypomelanosis because the macules were less white and less well demarcated. Glyphic markings were essentially absent in macular hypomelanosis, but variably effaced in idiopathic guttate hypomelanosis. Distensibility of the macules was characteristically low in proportion to the loss of glyphic markings. The chief histologic finding was the absence of melanin in basal keratinocytes. Macular hypomelanosis and idiopathic guttate hypomelanosis are probably related disorders along a spectrum of depigmentation. Treatment with tretinoin for 4 months restored the elasticity, the glyphic markings, with a partial restoration of pigmentation.

Administration, Cutaneous↗
PubMed1999

Comparative effects of retinoic acid, glycolic acid and a lipophilic derivative of salicylic acid on photodamaged epidermis.

BACKGROUND: Studies comparing purported antiaging compounds are rare. OBJECTIVE: To compare in a randomized, placebo-controlled double-blind study 10% glycolic acid (GA), 2% 2-hydroxy-5-octanoyl benzoic acid (beta-lipohydroxy acid, LSA) and 0.05% all-trans-retinoic acid (RA). METHODS: Women volunteers treated one forearm twice daily with one of the active products and the other one with the vehicle. Comparative evaluations of efficacy were made using histochemistry and quantitative immunohistochemistry. RESULTS: Improvement in the various epidermal compartments was the most prominent finding at the RA-treated site. The LSA-treated site also exhibited similar positive changes, although to a lesser degree. GA showed no significant effect. CONCLUSION: In the presently tested concentrations and formulations, RA had a beneficial impact upon the aging epidermis. LSA mimicked RA but with somewhat lesser efficacy. By contrast, GA appeared almost inactive.

Double-Blind Method↗
PubMed1998

The sodium hydroxide erosion assay: a revision of the alkali resistance test.

Burckhardt proposed the alkali resistance method as a means of assessing the integrity of the stratum corneum barrier in 1947. Researchers after Burckhardt largely found the test unreliable and nonreproducible; it therefore fell into disuse worldwide. We have upgraded the procedure by exposing the skin to 1.0 M sodium hydroxide under strictly specified conditions for successive 1-min periods until the emergence of the first erosions, revealed by staining with nitrazine yellow. Histology showed that the erosions were follicular and limited to the epidermis. The test was highly reproducible and repeatable. We demonstrated the usefulness of the test in the following ways: (1) the erosion time increased with aging, correlating with a thickened horny layer; (2) as few as five Scotch tape strippings greatly decreased the erosion time, although transepidermal water loss was only slightly increased; (3) slight damage to the horny layer by a 24-h exposure to 0.01% sodium lauryl sulfate sharply reduced the erosion time; (4) the erosion time decreased after daily open applications for 3 weeks of clobetasol propionate, corresponding to the thinned horny layer; (5) daily applications of petrolatum increased the erosion time. This new version of the alkali resistance test, renamed the sodium hydroxide erosion assay, promises to be a useful tool for studying the horny layer barrier in healthy and diseased skin.

Administration, Topical↗
PubMed1994

Determination of density of follicles on various regions of the face by cyanoacrylate biopsy: correlation with sebum output.

The density of follicles on various regions of the human face has received scant attention. We used cyanoacrylate follicular biopsies to determine the number of follicles on the forehead, cheek, chin and nose of 12 healthy adult white women. Sebum output was assessed on the same regions by means of Sebutape. The density of follicles and sebum output followed a centrolateral decreasing gradient. There was no correlation between these two parameters. These regional patterns are important for studies of the pathogenesis of common disorders of the face and their response to treatment.

Adult↗
PubMed1984

Age differences in poison ivy dermatitis.

In both man and animals, cell-mediated immunity diminishes with advanced age. Because poison ivy is a very common allergy, we evaluated age-associated differences in the contact allergic reaction to Rhus. Oleoresin patch tests were applied to two age cohorts (18-25 versus 65-84) each of 14 healthy white subjects. In the elderly, the allergic reaction developed more slowly, the inflammatory response at peak was greatly diminished and the dermatitis lasted longer and seemed to be more pruritic.

Adolescent↗