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Biomedical subjects

E Berardesca

Publications and source records attributed to E Berardesca.

78 records · Page 5Linked to original sources
PubMedDate not supplied

Detection of skin irritation potential of cosmetics by non-invasive measurements.

This study analyses the ability of four non-invasive techniques (laser Doppler velocimetry, evaporimetry, chromametry and corneometry) to discriminate between irritant and non-irritant products, when compared to appropriate controls, and to detect subliminal changes in barrier function and erythema. These changes, which remain undetectable in the traditional visual and palpable clinical assessment, can be used as early reactions that are followed by the development of overt skin irritation. Laser Doppler velocimetry and evaporimetry were good discriminators between irritant and non-irritant substances, whereas corneometry and chromametry did not clearly distinguish between them. Laser Doppler velocimetry and evaporimetry detected early stages in the development of an irritant reaction before it became visible, but chromametry was not able to detect an early irritant response. It was concluded that non-invasive measurements could improve the quality and relevance of data obtained from human irritation testing, since the data they provide are objective, quantitative and sometimes subclinical, which also allows the concentration of a positive control to be reduced, resulting in the induction of less skin damage in human volunteers and reducing the ethical concerns related to the deliberate induction of an irritant response in a 'healthy' volunteer.

Adult↗
PubMedDate not supplied

Physiological changes in skin barrier function in relation to occlusion level, exposure time and climatic conditions.

Skin occlusion is a condition encountered with various articles as part of everyday life and resulting changes in skin barrier physiology often remain unnoticed. In the present study we aimed to understand the impact of absorbent feminine hygiene articles, one vapor-permeable and one vapor-impermeable, on skin hydration in response to exposure time and different environmental climatic conditions. Using a forearm model, volunteers were patched with moistened vapor-permeable and -impermeable articles in parallel for 1, 3, and 6 h and under different climatic conditions (i.e. 20 degrees C/30% relative humidity, 25 degrees C/50% relative humidity, 30 degrees C/ 75% relative humidity). The physiological changes in the skin barrier function were measured via skin hydration, evaporation of superficial water (skin surface water loss, SSWL) and relative humidity in the microclimate between skin and occlusive article (RH(mc)). The results show that skin hydration, SSWL, and RH(mc) under a vapor-permeable article are reduced versus the vapor-impermeable article for all exposure times at 25 degrees C and 50% relative humidity. SSWL and RH(mc) decrease from their 1-hour peak values with increasing exposure time, while skin hydration decreases only after 3 h of exposure. Lower environmental temperature (20 degrees C) and lower relative humidity (30%) have little impact on the reduction of SSWL and RH(mc,) but more so on the reduction of skin hydration. Higher temperature (30 degrees C) and higher relative humidity (75%) increase RH(mc) and skin hydration under both vapor-permeable and -impermeable articles while SSWL is reduced under the vapor-impermeable article under these conditions. In conclusion, vapor-permeability is the key factor for physiological changes in the barrier function of the skin under occlusion, exposure time and climatic conditions being modulating factors. These findings have been integrated into a model of skin hydration under occlusion in the context of absorbent hygiene articles. While current vapor-impermeable articles are effective in reducing the excessive moisture on the skin due to bodily discharge, vapor permeability adds a further measurable benefit in reducing skin overhydration.

Adult↗
PubMedDate not supplied

Effects of prolonged occlusion on stratum corneum barrier function and water holding capacity.

PURPOSE OF THE STUDY: We aimed to evaluate whether prolonged occlusion can induce stratum corneum barrier damage, alterations in stratum corneum hydration or water-holding capacity (WHC) lasting longer than the occlusion time. MATERIALS AND METHODS: 12 subjects were occluded on the forearm for 24, 48, 72 and 96 h. Two hours after occlusion removal, transepidermal water loss (TEWL) and skin hydration were measured and a sorption-desorption test performed. RESULTS: TEWL showed an increase reaching a plateau on day 2. Hydration and WHC did not show significant changes. Hygroscopicity showed the highest level on day 1, decreasing during the following days. A highly significant correlation between capacitance values and the WHC could be detected (p < 0.0001, r = 0.8206). No correlation could be detected between hygroscopicity and TEWL. CONCLUSIONS: Prolonged occlusion induces barrier damage without skin dryness. Occlusion also induces an increased hygroscopicity. A correlation between these two findings could not be proven.

Adult↗
PubMedDate not supplied

Transepidermal water loss and skin surface hydration in the non invasive assessment of stratum corneum function.

Transepidermal water loss (TEWL) and water content of the stratum corneum, when measured simultaneously, provide important information regarding skin function. On the basis of the model presented, it is possible to differentiate dry senile skin from dry pathological skin (such as psoriasis, atopic dermatitis, irritant reaction), clinically involved or uninvolved. Pathological dry skin, because of the impaired barrier function is associated with increased TEWL and low corneum water content. Senile skin, on the other hand, shows both, decreased TEWL and stratum corneum water content. It is suggested that with this model it may be possible to differentiate uninvolved pathologic from healthy skin.

Aging↗