References of "Exogenous Dermatology : Physical, Chemical, Biological"
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See detailRepair kinetics of stratum corneum under repeated insults.
Uhoda, Emmanuelle ULg; Franchimont, Claudine ULg; Debatisse, B. et al

in Exogenous Dermatology : Physical, Chemical, Biological (2004), 3

Background. The stratum corneum (SC) structure and functions are altered by surfactants. Enhancing the repair mechanisms is a goal for some skin care formulations. Aim. To design an experimental procedure ... [more ▼]

Background. The stratum corneum (SC) structure and functions are altered by surfactants. Enhancing the repair mechanisms is a goal for some skin care formulations. Aim. To design an experimental procedure allowing the discrimination of repair efficacy for topical products applied to threatened SC. Method. Controlled SC strippings followed by repeated forearm soak sessions in surfactant solutions were used to compromise the SC barrier function in 20 volunteers. Two test formulations were compared. They were applied twice daily for 2 weeks before initiating the SC damages, and for the next 2 weeks while sustaining the procedure of soak sessions. Daily assessments involved objective measurements of parameters including TEWL, the value of the passive sustainable SC hydration and the epidermal turnover rate using the dihydroxyacetone (DHA) test. Result. The experimental procedure allowed to clearly distinguish the differences in the kinetics of SC repair between the topical formulations. In the present study design, the repair of the barrier function mirrored the SC renewal. Conclusion. The present experimental design slows down the repair rate of the SC barrier function. Thus, it increases the sensitivity of biometrological measurements assessing some of the major SC properties. It also better mimicks the common in vivo situation experienced by subjects chronically exposed to irritant xenobiotics. [less ▲]

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See detailComparative clinicopathological manifestations of human aspergillosis. A review.
Pierard, Gérald ULg; Arrese Estrada, Jorge ULg; Quatresooz, Pascale ULg

in Exogenous Dermatology : Physical, Chemical, Biological (2004), 3

Aspergillus species are important fungi of the environment, some of them being responsible for severe infections. Many distinct diseases form the human aspergillosis spectrum. The pathomechanisms differ ... [more ▼]

Aspergillus species are important fungi of the environment, some of them being responsible for severe infections. Many distinct diseases form the human aspergillosis spectrum. The pathomechanisms differ according to the affected organ and the immune status of the patient. The fungus can be responsible for allergic reactions. It may also act as a saprophytic colonizer of air spaces. Infection may remain limited to the skin and nails. It may also be invasive, particularly in immunocompromised patients, in the lungs, paranasal sinus and gastro-intestinal tract. Hematogeneous disseminated aspergillosis represents another dramatic form of the disease. [less ▲]

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See detailPitted keratolysis: new ultrastructural insight in keratohyalin granule and corneodesmosome alterations.
Hermanns-Le, Trinh ULg; Garcia, R.; Arrese Estrada, Jean-Marie ULg et al

in Exogenous Dermatology : Physical, Chemical, Biological (2004), 3

Background: Pitted keratolysis (PK) is a superficial cutaneous infection caused by different species of bacteria. It is characterized by discrete crateriform and malodorous pits and erosions coalescing to ... [more ▼]

Background: Pitted keratolysis (PK) is a superficial cutaneous infection caused by different species of bacteria. It is characterized by discrete crateriform and malodorous pits and erosions coalescing to form bizarre figures on the soles. Objective: To investigate the process of corneocyte shedding in PK. Method: Biopsies from typical lesions of three patients were investigated by transmission electron microscopy. Results: Microorganisms were found both inter- and intracellularly in corneocytes and keratinocytes of the upper layers of the stratum spinosum. Bacteria exhibited different morphologic aspects related to their localisation in the epidermis. Keratohyalin granules were strikingly abnormal, showing sharp segregation between rounded dense areas and more electron-translucent areas. Some keratohyalin granules exhibited only alveolar dense areas. These altered keratohyalin granules were still present inside corneocytes. The corneodesmosomes at the bottom of the pits were in part cleaved leading to partial corneocyte dissociation. Conclusion: It is suggested that proteases secreted by the bacteria alter the structure of both the corneodesmosomes and the keratohyalin granules. The latter appeared more resistant to the normal processing of profilaggrin inside the corneocytes. [less ▲]

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See detailThe conundrum of inducible nitric oxide synthase in chronic leg ulcers.
Quatresooz, Pascale ULg; Paquet, Philippe ULg; Pierard, Gérald ULg

in Exogenous Dermatology : Physical, Chemical, Biological (2004), 3

Nitric oxide (NO) is a potent biological mediator that can be produced in wounds by activation of inducible nitric oxide synthase (iNOS). Its presence appears to be beneficial to the healing process by ... [more ▼]

Nitric oxide (NO) is a potent biological mediator that can be produced in wounds by activation of inducible nitric oxide synthase (iNOS). Its presence appears to be beneficial to the healing process by promoting vasodilation and boosting both migration and synthetic activity of fibroblasts. Chronic leg ulcers differ from acute experimental wounds because the connective tissue and microvascularization of the ulcer bed are strikingly remodelled in chronic wounds. In addition, a bacterial critical colonization from the environment is also often present and deleterious. As such, NO release in leg ulcers may prove to be beneficial by improving the microvasculature and fibroblast functions, and by its antimicrobial effect. However, any excess in NO could become cytotoxic for keratinocytes, thus impeding re-epithelialization. Furthermore, chronic NO release could be involved in the cancerogenesis process leading to Marjolin ulcer. In conclusion, NO induced by environment factors mediates contrasted effects in wound healing that may be beneficial or detrimental for the patient. [less ▲]

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See detailComparative clinical and electrometric assessments of the impact of surfactants on forearm skin.
Uhoda, Emmanuelle ULg; Paye, Marc; Pierard, Gérald ULg

in Exogenous Dermatology : Physical, Chemical, Biological (2003), 2

Surfactant-based skin care products can induce minimal to more severe alterations to human stratum corneum (SC). These changes can be conveniently assessed using electrometric devices. Four different ... [more ▼]

Surfactant-based skin care products can induce minimal to more severe alterations to human stratum corneum (SC). These changes can be conveniently assessed using electrometric devices. Four different surfactant-based solutions were applied on the forearms of 10 healthy volunteers following a soap chamber test method. The 2-day patch testing was followed by a 2-week follow-up. Clinical and instrumental assessments were performed at 7 time points. Data generated by the Corneometer® CM820, the DermaLab Moisture Module® and the Nova Dermal Phase Meter (DPM)® 9003 were compared. The significant differences between the product aggressiveness to the SC were similarly disclosed by the Corneometer® and the DermaLab Moisture Module®. The ranking of product aggressiveness given by the 3 devices 5 days after patch removal was similar to that given by the clinical assessment of erythema. A high level of correlation were found between the values yielded by the immediate and continuous mode assessments using the DermaLab Moisture Module with the Pin Probe, while the correlation was weaker with the Nova DPM®. This finding may be related to the fact that the Nova DPM is influenced by the accumulation of the transepidermal water loss in the continuous mode assessment while there is no significant occlusion effect of the DermaLab Moisture® Pin Probe that is more representative of the initial level of SC hydration. In conclusion, the Corneometer® and the DermaLab Moisture Module® respond similarly to changes in the SC content. This finding is different from some previous reports. [less ▲]

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See detailBiometrological assessment of skin protectors against moderate cold threat.
Claes, Geert; Pierard, Gérald ULg

in Exogenous Dermatology : Physical, Chemical, Biological (2002), 1

Background : Cold injuries represent a serious problem in winter sport practice and other outdoor activities. Some protection is expected to be achieved by specific topical preparations aiming at ... [more ▼]

Background : Cold injuries represent a serious problem in winter sport practice and other outdoor activities. Some protection is expected to be achieved by specific topical preparations aiming at decreasing heat loss by water evaporation from the skin. Objective : To compare the efficacy of 6 topical formulations enriched or not in rubefacients. The role of the vehicle was also assessed. Methods : A total of 30 trained cyclists tested the products on their forearms. The skin temperature and electrometric values were recorded at baseline following applications of the test products, and after 30 min-bicycle riding in moderately cold and humid outdoor conditions. Results : At baseline, skin temperature was increased by rubefacients dispersed a lipogel and o/w emulsion. This parameter decreased at all test sites after riding, but the values remained higher at the rubefacient-treated sites compared to the control untreated site. The oil and lipogel formulations achieved partial occlusion decreasing the transepidermal water loss. This effect was maintained after exercise without, however, hindering sweating. Conclusion : Among the presently tested formulations, the rubefacient-enriched lipogels appeared to be the most efficient formulations for maintaining skin temperature in the normal range during sport practice in a moderately cold environment. [less ▲]

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See detailBeyond a glimpse at seasonal dry skin. A review.
Franchimont, Claudine ULg; Pierard, Gérald ULg

in Exogenous Dermatology : Physical, Chemical, Biological (2002), 1

On clinical grounds the so-called dry skin corresponds in reality to a rough sometimes flaky and scaly stratum corneum. The spectrum of xerotic disorders is quite large encompassing diverse etiologies and ... [more ▼]

On clinical grounds the so-called dry skin corresponds in reality to a rough sometimes flaky and scaly stratum corneum. The spectrum of xerotic disorders is quite large encompassing diverse etiologies and physiopathological pathways. The clinical assessment of these conditions relies on close visual and tactile inspection. EEMCO guidances were proposed in this field for subject and expert evaluations. Scoring systems include analogue scales, the overall dry skin score (ODS) and the SRRC score combining the grading of scaliness, roughness, redness and cracks. The dry skin extent area and severity index (DASI) is defined for the dermatological evaluation of the entire body surface. The use of a video camera equipped with an internal ultraviolet light illumination unit is very informative and allows better comparative assessments. [less ▲]

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See detailAndrogenic alopecia and stress-induced premature senescence by cumulative ultraviolet light exposure.
Franchimont, Claudine ULg; Uhoda, I.; Saint Léger, Didier et al

in Exogenous Dermatology : Physical, Chemical, Biological (2002), 1

Background : Ultraviolet light radiations (UVR) may be responsible for hair cycle synchronization and telogen effluvium in the animal and humans. The effect if any of cumulative UVR on chronic hair ... [more ▼]

Background : Ultraviolet light radiations (UVR) may be responsible for hair cycle synchronization and telogen effluvium in the animal and humans. The effect if any of cumulative UVR on chronic hair shedding and androgenic alopecia (AGA) is largely unknown. Objective : To compare the severity of AGA with the extent in solar elastosis. Method : The present study combining immunohistochemistry and computerized image analysis was undertaken in 140 men with AGA and 50 non-alopecic men. Solar elastosis was identified using the antibody to lyzozyme, and collagen was revealed by sirius red staining. The number and diameter of hair shafts were also assessed. Results : The scalp dermis was significantly thicker in AGA than in unaffected subjects. The difference was mainly due to a more severe elastosis in baldness. The earliest signs of solar elastosis preceded hair thinning. When elastosis was thicker than 0.2 mm, a negative exponential correlation was found between hair diameter and severity in solar elastosis. Conclusion : Chronic UVR exposure of the scalp may affect the hair cycle and be one exogenous factors influencing negatively the progression of AGA. The induction of stress-induced premature senescence (SIPS) through reactive oxygen species and microinflammation might be operative at the level of the follicular stem cells. [less ▲]

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See detailAccidental radiogenic ulcer of the fingers in an industrial setting.
Heymans, Olivier; Van Zeele, D.; Arrese Estrada, Jorge ULg et al

in Exogenous Dermatology : Physical, Chemical, Biological (2002), 1

The incidence of accidental radiogenic damage to the skin is low. We report a case of delayed ulcerative contact radiodermatitis following accidental industrial exposure. Recurrent ulcerations of the ... [more ▼]

The incidence of accidental radiogenic damage to the skin is low. We report a case of delayed ulcerative contact radiodermatitis following accidental industrial exposure. Recurrent ulcerations of the fingers were treated successfully by flap surgical reconstruction. [less ▲]

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See detailUltrasound shear wave propagation in Caucasian hair.
Franchimont, Claudine ULg; Goffin, Véronique ULg; Uhoda, Emmanuelle ULg et al

in Exogenous Dermatology : Physical, Chemical, Biological (2002), 1

Background : The aspect of hair depends on the spatial organization of the hair shafts and on their chemical, physical and structural integrity. Some genetic disorders and exogenous influences may affect ... [more ▼]

Background : The aspect of hair depends on the spatial organization of the hair shafts and on their chemical, physical and structural integrity. Some genetic disorders and exogenous influences may affect it. Aims : In vivo objective assessments are welcome in order to compare the consequences of hair damages and to assess the kinetics of the changes occurring in time after damaging or attempting to repair the hair structure. Method : Ultrasound shear wave propagation measured on hair is introduced as an objective non-invasive method with in vitro and in vivo applications. Results : With multiple measurements made on the scalp of 72 Caucasians, hair felting following damage appeared to be associated with an increase in the coefficient of variation of the shear wave velocity measurements. Maximum hydration of hair locks increased the shear wave velocity in vitro and decreased the intraindividual range of data. The relevance of the method and reproducibility of data was influenced by the experimentalist skill. Conclusion : Ultrasound shear wave propagation on hair is influenced by the physical integrity of the hair shafts and on their three-dimensional arrangement. [less ▲]

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