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Biomedical subjects

G E Piérard

Publications and source records attributed to G E Piérard.

At least 19 recordsLinked to original sources

Glutathione-S-transferase pi expression in toxic epidermal necrolysis: a marker of putative oxidative stress in keratinocytes.

BACKGROUND: Toxic epidermal necrolysis (TEN) is a dramatic drug-induced emergency related to extensive destruction of the epidermis. There is evidence that its pathomechanism involves impaired detoxication of xenobiotics. Glutathione-S-transferase pi (GST-pi) is a phase II detoxifying enzyme involved in drug metabolization by human keratinocytes. METHOD: Immunohistochemistry was performed in order to assess the expression of GST-pi in keratinocytes of TEN, other cutaneous adverse drug reactions and bullous pemphigoid. RESULTS: GST-pi was disclosed in the involved epidermis of 16/16 TEN patients. It was present in the cytoplasm of suprabasal keratinocytes. GST-pi was also expressed in the clinically uninvolved skin in a majority (8/12) of TEN patients. By contrast, it was rarely and poorly expressed in the other tested dermatoses. CONCLUSION: The pathomechanism of TEN is not related to an impaired quantitative expression of GST-pi. GST-pi expression is an early event in TEN. As oxidative stress is a major inducer of GST-pi, this mechanism might be involved in TEN. Its GST-pi expression mainly restricted to the suprabasal keratinocytes suggests that the pathomechanisms leading to keratinocyte death in TEN are distinct at different levels of the epidermis.

Adult↗

Delayed reepithelialization and scarring deregulation following drug-induced toxic epidermal necrolysis.

A 51-year-old Caucasian woman developed severe drug-induced toxic epidermal necrolysis (TEN) due to allopurinol. The withdrawal of the culprit drug was unfortunately delayed, and dramatic retardation of reepithelialization was observed. At that stage of disease evolution, an inflammatory cell infiltrate was present in the dermis. Coverage of eroded lesions by frozen cultured keratinocyte allografts failed to hasten reepithelialization compared to ungrafted sites. This unusual protracted TEN evolution was followed by the development of extensive hypertrophic and keloid scars. Several biopsies were taken over 6 months. The histologic presentation of the grafted and ungrafted eroded scar tissues looked similar. Both the number and size of the Factor XIIIa-positive dermal dendrocytes, as well as the number of alpha-actin-positive myofibroblasts showed a marked increase between weeks 2 and 12 after grafting. They were reduced after 6 months when the scarring process was stabilized. alpha1 [IV] collagen was never expressed over the eroded scars. Similar to burn patients, delayed reepithelialization might be a risk factor for abnormal scarring in TEN. Cultured keratinocyte allograft apparently offered no improvement in reepithelialization and did not prevent abnormal scarring in this TEN patient.

Allopurinol↗

Dynamics of skin barrier repair following topical applications of miconazole nitrate.

The skin barrier function (SBF) is an important aspect of skin biology, particularly in the elicitation of inflammation. The SBF recovery rate after tape stripping and surfactant challenge can be assessed by measuring the transepidermal water loss (TEWL). Previous clinical studies have shown some inflammatory effect after topical applications of miconazole. The aim of this study was to compare the effect of pastes (petrolatum and 15% zinc oxide) containing or not miconazole nitrate on controlled impaired SBF. Fifteen volunteers were enrolled. In each subject, successive cyanoacrylate skin surface strippings were harvested from 5 sites of the volar forearm until TEWL raised above 15 g/cm(2)/h on all test sites. In addition, one daily soak session with a 0.2% dishwashing liquid further damaged the SBF. Each of the test formulations was applied twice daily for 5 days at two dosages, namely 1 and 2 mg/cm(2), on randomized test sites. Another site remained untreated. TEWL was measured daily for 5 days. A fastened SBF repair was observed on all treated sites, particularly where the largest amount of the products had been applied. A faster SBF recovery rate was obtained at the site receiving the miconazole nitrate paste. We conclude that the occlusive effect of a paste helped mitigate SBF defect. The adjunction of miconazole nitrate improved the efficacy.

Administration, Topical↗

Skin immunoglobulin deposition following intravenous immunoglobulin therapy in toxic epidermal necrolysis.

Human intravenous immunoglobulins (IVIg) which contain anti-CD95 antibodies have been proposed to treat toxic epidermal necrolysis (TEN). Presently, there is no evidence that IVIg reach the keratinocytes in TEN patients. The aim of this study was to assess the Ig distribution in the serum, blister fluid and skin of six consecutive TEN patients treated with IVIg (1 g/kg/day) for 3 days. They were compared with five TEN patients who only received supportive therapy. In all patients, IgA, IgM and IgG concentrations were measured in the serum and blister fluid using an immuno-nephelometric method. Immunohistochemistry was performed on skin biopsies taken from both TEN clinically involved and uninvolved skin to search for IgG deposits. On admission, the IgG concentrations were significantly higher in both TEN serum and TEN blister fluid compared with their respective IgA and IgM contents. The IgG, IgA and IgM concentrations in blister fluid were significantly lower than their respective serum concentrations. The serum and blister fluid IgG concentrations, but not that of IgA and IgM, were markedly increased at the completion of the IVIg treatment. By contrast, they remained unchanged in the TEN patients that were untreated with IVIg. In the IVIg-treated patients, the IgG intraepidermal deposits raised markedly in both TEN-involved and uninvolved skin. This was not the case in patients who did not receive IVIg. These results suggest that IVIg perfusions brought a prominent increase in IgG concentration in the serum, blister fluid and epidermis of both TEN-involved and clinically uninvolved skin. The presence of potentially protective IgG in TEN epidermis following IVIg treatment could help limiting the disease progression.

Adolescent↗

Dandruff-associated smouldering alopecia: a chronobiological assessment over 5 years.

BACKGROUND: In some individuals, dandruff may be recurrent and even chronic. This represents a difficult-to-treat condition. Excessive hair shedding and diffuse alopecia may develop. OBJECTIVES: To evaluate the chronobiological aspects of dandruff, hair shedding and alopecia. METHODS: This study was performed in eight men suffering from such a scalp condition. They were examined 40 times at regular intervals for five consecutive years. Hair-density assessments and trichograms were performed at least twice per trimester on the parietal region of the scalp, corresponding to an area where dandruff was present. RESULTS: A positive correlation was found between the percentage of telogen hairs and dandruff severity as assessed by the squamometry index. Bimodal yearly biorhythms were found for dandruff severity, telogen counts and hair loss between two consecutive visits. The chronobiological fluctuations were prominent in some study participants, but remained inconspicuous in others. The biorhythms were almost synchronized in all participants, showing variations over the year. CONCLUSIONS: The biorhythms on the hair cycle in dandruff are not fundamentally different from those previously reported in subjects without dandruff. The periodicity may be an intrinsic feature of human skin.

Adult↗

Healing effect of ketanserin on chronic leg ulcers in patients with diabetes.

BACKGROUND: The treatment of chronic leg ulcers remains a stubborn problem in many patients. Topical 2% ketanserin ointment, a 5HT2-serotoninergic blocking agent, has been reported to improve healing of decubitus, venous, diabetic and ischaemic ulcers. METHOD: The present double-blind intra-individual comparative study was performed in 12 women with diabetes presenting with at least two similar leg ulcers. In each subject, the two lesions were randomly assigned to be treated for 8 weeks by 2% ketanserin ointment or its unmedicated vehicle. OBJECTIVE: assessments of the dynamics of wound healing were performed using computerized morphometry. Evaluations were performed at 2-week intervals for 8 weeks. RESULTS: A significant decrease in relative wound area was observed on the ketanserin-treated ulcers compared with the placebo group. CONCLUSION: Topical ketanserin is a valuable therapy for difficult-to-treat leg ulcers.

Administration, Cutaneous↗

High-resolution epiluminescence colorimetry of striae distensae.

BACKGROUND: Colours of striae distensae are often different from that of the surrounding skin. A close look using dermoscopy discloses distinct patterns of melanized networks at these sites. The aim of the study was to design a method of high-\resolution analytical analysis of the skin colours using the combination of photographic dermoscopy and small field reflectance colorimetry. METHODS: Clinical photographs were taken from striae distensae and their surrounding skin using a Dermaphot (Heine Optotechnik, Hersching, Germany). A final magnification of 125x was obtained on paper photographs. The reflectance colorimeter Visi-Chroma VC-100 (Biophotonics, Lessines, Belgium) was used to measure colours of the pigmentary networks in the L*a*b* system. Differential colour parameters (deltaE*ab, deltaL*, deltaa*, deltab*) were calculated for each case between the lesional and the surrounding normal skin, and between the melanized reticulated pattern and the enclosed lighter areas. RESULTS: Objective colorimetric assessments distinguished four distinct types, namely striae albae, striae rubrae, striae caeruleae and striae nigrae. The latter peculiar hyperpigmented type of striae distensae was specifically identified by epiluminescence examination in dark-skinned subjects. The fine-melanized honeycomb network present on the adjacent intact skin was reshaped inside striae in a streaky pattern perpendicular to the striae axis. Strong linear correlations were found between all combinations of deltaL* and deltab* evaluating colours of the reticulated and the honeycomb alveolar patterns both inside and outside the striae distensae. By contrast, no correlations were found between deltaa* and the other colorimetric parameters. CONCLUSION: The direct and/or indirect influences of melanocyte mechanobiology appear to have a prominent effect on the various colours of striae distensae.

Adult↗

Cutaneous myospherulosis and membranous lipodystrophy: extensive presentation in a patient with severe steroid-induced dermal atrophy.

Myospherulosis is a rare disorder that may develop in various organs including the skin. It is characterized by a typical histological presentation resulting from the interaction between erythrocytes and lipids. We present a case of cutaneous myospherulosis associated with membranous lipodystrophy. The lesions were supervening on severe steroid-induced skin atrophy upon which ointments had been applied.

Atrophy↗

Skin capacitance mapping of psoriasis.

BACKGROUND: The pathobiological dynamics of psoriatic lesions are complex and difficult to perceive by clinical inspection alone. Non-invasive bioengineering methods may prove to be useful in this field. OBJECTIVE: To identify some subtle capacitance variations in the stratum corneum of chronic psoriasis lesions. METHOD: The newly developed method of skin capacitance imaging was used to provide non-optical images of the hydration of the superficial layers of the stratum corneum. RESULTS: Compared to the uninvolved skin, psoriatic lesions usually showed an overall lowered capacitance, admixed with foci of moderately higher capacitance. Still other sharply circumscribed blotches with higher capacitance were present. The latter aspect corresponded to inflammatory areas. Sweating appeared markedly impaired inside the lesions. The fingerprint of some patients was altered, thus potentially interfering with the current biometric security procedures using the same method. CONCLUSION: Skin capacitance imaging is a non-invasive, non-optical method that distinguishes three contrasting levels of stratum corneum hydration in psoriatic lesions. The lowest capacitance level probably corresponded to xerotic orthokeratosis. The medium capacitance level presumably identified foci of parakeratosis and clumps of neutrophils. The highest capacitance level suggested exsudation at the site of prominent vessel dilation and dermal inflammation. Impaired sweating in the psoriatic lesions may potentially interfere with body thermoregulation.

Dermatoglyphics↗

[Hic et Nunc. Naevus or melanoma?].

In Wallonia, the incidence of cutaneous melanoma has steadily increased over the past decades. Hopefully, the early diagnosis made at the premetastatic stage has benefited from great advances both in the clinical and laboratory fields. Thanks to the "Groupement Oncologique Universitaire Wallonie-Liège" (GOUWL) organization, some efforts are currently made in order to better frame and normalize the management of cancer patients. Some medical staffs involved in prospective clinical research bring by their own experience further practical insights for the benefit to the patients. In this field, Belgium is not destituted. We report a brief review of the contribution of the Mosan Study Group of Pigmentary Tumors (GMETP) at the University Hospital of Liège.

Belgium↗

[Cutaneous signs of endocrinopathies].

Some cutaneous lesions accompany or reveal endocrine disorders. Identifying the endocrinopathy is very important because it sometimes allows corrective rather than symptomatic treatment. The most frequenly involved diseases include thyrotoxicosis, hypothyroidism, the auto-immune disorders of thyroid, Cushing syndrome, Addison disease, acromegaly, androgen-dependent disorders, hypopituitarism, hypoparathyroidism, pseudohypoparathyroidism and diabetes mellitus.

Endocrine System Diseases↗

[Hydrocortisone 17-butyrate (Locoid), a thirty-year ongoing innovative drug].

Since half a century, dermocorticoids represent worthy compounds in dermatological therapy. About thirty years ago, hydrocortisone 17-butyrate was introduced on the Belgian market. This compound combines good efficiency and reduced risk of side effects. Its topical formulations have been enriched over time. The original Locoid lipocream and Locoid Crelo presentations confer remarkable qualities to the product. We report a synopsis of clinical and translational studies devoted to this unique dermocorticoid.

Dermatologic Agents↗

[How I treat...topical treatment of plaque type psoriasis by the combination of calcipotriol and betamethasone dipropionate].

The combination of calcipotriol and betamethasone dipropionate in a single topical formulation is a recent advance in treatment of plaque type psoriasis. Studies rooted on evidence-based medicine have been recently published. We report a synthesis and a critical analysis, critical analysis of these investigations, and translate their data with a view to apply them in daily practice.

Administration, Topical↗

[The skin and menopause].

The estrogen deficit occurring at menopause manifests itself under various modalities in the diverse organs and their functions. Skin does not escape this global involutive process. In addition to the effects of chronological ageing, sunlight exposure and other environmental and endogenous stimuli, the climacteric appears to exert some dramatic consequences on skin biology and aspect. The epidermis, its adnexae and the dermis are altered by this process. The epidermis may become xerotic and exhibits altered functions. The dermis thins out and its elasticity decreases in concert with the decline in bone mass. The skin microcirculation is impaired. These aspects are some of the better-worked out skin climacteric changes of which in turn seem to be stabilized or in part reversible with hormone replacement therapy (HRT).

Female↗

[How I treat...diaper dermatitis].

Diaper dermatitis is the most frequent skin disorder of the newborn. Several clinical types are distinguished. The most frequent type results from increased fragility of the newborn buttock skin when covered by diapers. According to the mechanisms involved and the severity of the dermatitis, one can distinguish the intertrigo of the chubby baby, and the so-called "W", "Y" and "red panties" types of diaper dermatitis. When the effects of occlusion are not controlled by adequate absorption by the diapers maceration of the stratum corneum occurs. As a result, degradation of the skin barrier function takes place. In addition, the value of the coefficient of friction of the skin increases with epidermal weakening to rubbing. In addition, fecal enzymes alter urines and skin. Judicious hygiene measures and a correct choice of care and diapers are mandatory. Cutaneous colonisation by microorganisms, in particular the yeasts Candida spp, is the main complication. Adequate preventive and curative measures can combat diaper dermatitis with confidence. A miconazole paste allows to improve the tribological properties of the interface between diapers and the skin. It also corrects the degradation of the skin barrier function, reduces inflammation and abates the impact of Candida spp. in the pathogenesis of the skin disorder.

Antifungal Agents↗