C. Letawe

Effect of Hormone Replacement Therapy for Menopause on the Mechanical Properties of Skin

OBJECTIVE: To evaluate the effect of hormone replacement therapy (HRT) for menopause on the mechanical properties of the skin in healthy women.

Mechanical Properties of the Diabetic Waxy Skin

BACKGROUND In some diabetic patients, the skin of the hands has a waxy appearance. OBJECTIVE To study subclinical skin stiffening in diabetic patients using a noninvasive, in vivo suction device measuring skin extensibility and elasticity. Skin thickness was also measured by high-resolution ultrasonography. METHODS Evaluations were made on the dorsum of the hands and on the volar aspect of the forearms. RESULTS In type 1 diabetic patients, the extensibility of skin was decreased while values of thickness and elasticity were increased. These alterations were most prominent on the hands. Similar modifications, although less pronounced, were also found in type 2 diabetic subjects. CONCLUSION The reported biomechanical changes indicate the presence of subclinical skin stiffening in many patients with diabetes mellitus. Such noninvasive biometrological evaluations could be used for monitoring, rating and correlating some diabetes-associated disorders.

Effect of organic solvents on normal human stratum corneum : Evaluation by the corneoxenometry bioassay

BACKGROUND Organic solvents alter the stratum corneum structure and barrier function. OBJECTIVE To measure the effect of various solvents upon human stratum corneum using the ex vivo corneoxenometry bioassay which is a variant of corneosurfametry. METHODS Corneoxenometry entails collection of human stratum corneum by cyanoacrylate. The material is immersed in organic solvents for periods ranging from 1 to 120 min. After staining the samples with a toluidine blue-basic fuchsin solution, the color is measured using reflectance colorimetry. Solvent aggressivity to the stratum corneum correlates with the color darkening of the samples. RESULTS The least aggressive solvent was hexane, followed by ethanol, methanol, hexane-ethanol, chloroform, chloroform-methanol and hexane-methanol. The influence of contact time between solvents and the stratum corneum showed a logarithmic pattern which varied according to the solvent. CONCLUSION Data are in line with previous experiments conducted in vivo and in vitro, thus indicating the predictive value of corneoxenometry. Such a bioassay may avoid hazards of some in vivo human testings.

Gravitational syndrome and tensile properties of skin in the elderly.

Background: To evaluate the influence of gravitational edema due to chronic venous insufficiency upon the tensile properties of skin. Method: A total of 30 women aged 66–75 years participated in the study. Evaluations were made twice in the same subjects following the use or nonuse of daytime elastic compression. Mechanical properties of the skin were measured in the midportion of the legs using a computerized suction device. Results: The consistency of skin which shows abnormal rheological characteristics at the site of gravitational edema was significantly modified by compression therapy. Both skin extensibility and hysteresis were increased after wearing tight stockings although the biologic elasticity remained unchanged. Conclusion: Noninvasive measurements of the tensile properties of the skin represent an objective assessment of the severity of leg edema and of its correction by compression therapy.

Squamometry in rating the efficacy of topical corticosteroids in atopic dermatitis

AbstractObjective: Squamometry is a non-invasive test allowing a reproducible rating of cutaneous xerosis including atopic dermatitis lesions. The method was used to compare the efficacy of proprietary topical corticosteroids in alleviating signs of atopic xerosis. Results: The steroid compounds and their vehicles improve the texture of the stratum corneum at different rates after treatment for 1 week. Some differences in efficacy may be explained by the nature of the vehicle, which enhances the basic pharmacological activity of the corticosteroid itself.

Temperature-Dependent Effect of Skin-Cleansing Products on Human Stratum Corneum

AbstractThe effect of temperature on surfactant-induced irritant reaction has not yet been thoroughly studied. This study was undertaken to evaluate the effect of temperature on the ex vivo corneosurfametry test, which is a nonanimal alternative method to evaluate the safety of cleansing products. The colorimetric index of mildness (CIM), which correlates with surfactant mildness, was measured using the corneosurfametry test performed on stratum corneum harvested from normal individuals. Sodium lauryl sulfate (SLS) at 1 and 2% concentrations and water were tested at 4, 20, and 40°C. In addition, 5% solutions of 14 proprietary skin-cleansing products were compared at 20 and 40°C. Surfactant CIM decreased with increasing temperature, and was significantly lower than water-CIM at each test temperature. A significant logarithmic correlation was found between the 20°C-CIM and the 40°C-CIM of all test products. The CIM intrain-dividual variations increased with the irritation potential of products. It is conclu...