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Biomedical subjects

Gérald E Piérard

Publications and source records attributed to Gérald E Piérard.

At least 19 recordsLinked to original sources

Spotlight on nail histomycology.

The misdiagnosis of onychomycosis delays the proper treatment of the nail condition. Nail histomycology refers to the microscopic examination of histologic sections prepared from nail clippings for the purpose of detecting the presence of fungi. This laboratory method is the most sensitive procedure for the diagnosis of onychomycosis. It allows for the visualization of the precise location of the invasive fungus inside the nail apparatus. The method also distinguishes various shapes of the fungal cells, in particular filamentous fungi, yeasts, conidia, and sporodochia. The correct diagnosis provided by histomycology combined with culture not only allows for more efficient expenditure of funds and services but also is important for the timely alleviation of the disorder.

Diagnosis, Differential↗

Diffuse dermal angiomatosis: A previously undescribed pattern of immunoglobulin and complement deposits in two cases.

Two cases of diffuse dermal angiomatosis are reported in middle-aged women. This rare disease of unknown origin is characterized by increased dermal angiomatosis and ulceration. The clinical and histologic presentations of the presently reported lesions were typical for this disorder. Endothelial cells exhibited a normal immunophenotype. The perivascular basement membranes showed a distribution of collagen alpha chains typical for blood vessels, but not for lymphatics. Immunohistochemistry revealed other undescribed features. At the site of the clinical lesions, linear and granular deposits of immunoglobulins A and M, and complement were found around the vessels and at the dermal-epidermal junction. The same deposits were also found restricted to the dermal-epidermal junction in the peripheral clinically intact skin. No serological signs of auto-immune disorder were detected in one patient. A monoclonal gammopathy was disclosed in the other patient. A pattern of immunoreactant deposits similar to that disclosed in the two patients was not found in the control specimens, and has not been described so far in other types of vascular hyperplasia and neoplasia. A pathogenic role of these deposits is unsettled and should be further explored.

Abdomen↗

Skin capacitance imaging and corneosurfametry. A comparative assessment of the impact of surfactants on stratum corneum.

Silicon image sensor (SIS) technology was recently introduced as an innovative tool (SkinChip, L'Oréal) providing sensitive imaging of the skin capacitance. This method can detect discrete focal variations in skin surface hydration, and thus early discrete manifestations of skin irritation induced by surfactants. In the present in vivo study, 2 neat and diluted shampoos, and 5% and 10% sodium laurylsulfate solutions were tested on human skin. Each surfactant solution was gently rubbed on the skin using wet hair wicks mimicking the casual use of a shampoo on the scalp. Clinical and SIS evaluations were carried out. In addition, the same products were tested using the ex vivo corneosurfametry bioassay performed on human stratum corneum (SC) harvested by cyanoacrylate skin surface strippings. The colourimetric index of mildness (CIM) was measured on these samples. The product reactivity with the SC was recognized by darker skin capacitance images, and by both lowered SkinChip-generated values and lowered CIM values. The extent in changes varied according to the nature of the test products and their concentrations. The SkinChip image changes likely corresponded to the acute surfactant-induced water swelling of the corneocytes. Skin capacitance imaging and corneosurfametry allow to disclose discrete surfactant-induced alterations of corneocytes.

Dermatitis, Allergic Contact↗

Mechanobiology and force transduction in scars developed in darker skin types.

BACKGROUND: Scarring is a complex process involving many cell types, cytokines and biological pathways including mechanobiology. Some subtle mechanical properties of skin can be assessed by measuring the speed of ultrasound shear wave propagation. The orientation of abnormal skin tension forces can be visualized, particularly in darker skin types, using dermoscopy showing distinct patterns of rete ridges' conformation. AIM: To assess some mechanobiological features of scars in darker skin types. PATIENTS AND METHODS: Large atrophic and hypertrophic surgical scars were examined on the trunk of 35 darker skin subjects. The surrounding skin was used as a comparator. Dermoscopic aspects were recorded. Resonance running time measurements (RRTM) were performed using a shear wave propagation device (Reviscometer). They were performed in four specific directions at given angles with regard to the long axis of the scar. The minimum, maximum and mean RRTM values were recorded at each site. RESULTS: Dermoscopy revealed patterns of melanin deposits in scars distinct from the normal honeycomb network seen in the surrounding skin. Hypertrophic scars showed a patchy pattern of large macular melanoderma dispersed in a lighter background. In these cases, low RRTM values were obtained with little variations according to the orientation of the measurements. By contrast, atrophic scars showed a streaky laddering melanotic pattern under dermoscopy. Higher RRTM values were often obtained, particularly in the transversal direction of the scars. Mechanical anisotropy was greater in the atrophic scars compared with the normal skin. DISCUSSION: Darker skin types represent a model for visualizing the main orientation of the epidermal rete ridges. A correlation was found between the pattern of melanized rete ridges of scars and the main orientation of the intrinsic forces in the skin.

Adult↗

Effect of a single overnight topical application of miconazole nitrate paste on acne papules.

BACKGROUND: The classical management of acne calls for prolonged oral and/or topical treatments; however, some patients request a rapid effect to make the papules disappear within a few hours or days. OBJECTIVE: To test the effect of a single overnight application of a paste containing 0.25% miconazole nitrate on acne papules, and comparison with the effect of the same but unmedicated paste. METHOD: Narrow-band reflectance spectroscopy was used to assess the changes in E index (erythema) after overnight application of the pastes. In the first study, a total of 117 acne papules were assessed in 15 adolescents. Measurements of the E index were performed at 24-h intervals for 4 days on acne papules and the surrounding normal-looking skin. The last two assessments were performed the mornings preceding and following, respectively, a single application of the medicated paste. The second part of the study consisted of a double-blind, split-face study on 25 adolescents with acne. They applied each of the two formulations on a randomized part of the forehead. A total of 161 acne papules received the medicated paste and 160 received the same but unmedicated paste. Measurements were performed the mornings before and after the overnight treatment. RESULTS: In the first part of the study, no significant daily difference was observed between the three series of pretreatment E indices, on both acne papules and normal skin. The treatment did not affect the E index of normal skin. By contrast, it decreased significantly the E index of the acne papules. The second part of the study also showed that the medicated paste significantly decreased the E index of acne papules. This effect was significantly (P < 0.05) superior to that of the unmedicated paste. CONCLUSION: A single overnight application of miconazole nitrate paste appears to reduce the erythematous aspect of acne papules.

Acne Vulgaris↗

Skin climacteric aging and hormone replacement therapy.

A gender perspective is indispensable for a full understanding of aging. Menopause is a turning point in women's lives. In addition to the effects of chronological aging, sunlight exposure, and other environmental and endogenous stimuli, the climacteric appears to exert some dramatic consequences on skin biology and aspect. The epidermis may become xerotic and exhibit 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 changes of the climacteric, which in turn seem to be stabilized or in part reversible with hormone replacement therapy (HRT). The HRT effect on menopause consequences on hair growth and sebum production is less impressive. This review summarizes some important impacts of the climacteric on skin, and highlights the benefits of HRT that may influence cosmetic dermatology.

Biomechanical Phenomena↗

The key role of corneocytes in pityrosporoses.

Pityrosporoses encompass various Malassezia-driven conditions. Dandruff and seborrheic dermatitis are members of this family of disorders. Their precise pathomechanisms have not been completely elucidated so far. This review focuses on the role of corneocytes in these disorders. Malassezia yeasts are not evenly distributed at the surface of the stratum corneum. Rather, they are clumped on some corneocytes while other corneocytes in their vicinity are almost free of these microorganisms. The corneocytes heavily coated by yeasts suggest a cell-related defect in the mechanisms controlling the skin biocene including the natural antimicrobial peptides and nitric oxide. Most environmental factors influencing pityrosporoses indeed affect the natural human defenses against certain microorganisms. We frame as a hypothesis that the primary defect in some Malassezia-driven disorders resides in the corneocytes and their precursor keratinocytes.

Dermatitis, Seborrheic↗

Spores, sporodochia and fomites in onychomycosis.

Onychomycosis is a frequent infection. Contagion rarely depends on direct contamination, but rather on environmental propagule dispersion including the intervention of fomites. The potential release of fungal cells in the environment from the affected nails has not been thoroughly studied. Observations made by histomycology suggest that arthroconidia and chlamydoconidia issued from invading fungi can be involved. In addition, the sporodochium, which is an exophytic fungal ball, may be attached underneath the distal free edge of some onychomycoses. It might represent an important source of fungal propagules in patients with poor nail trimming.

Aged↗

Blood vessel changes during pregnancy: a review.

The profound endocrine upheaval of pregnancy is frequently associated with changes in the function and structure of the blood and lymph microvasculature of the skin and mucosae. Palmar erythema is frequent but rarely severe and is associated with burning sensations. Spider telangiectasias develop in the majority of pregnant White women but are less often identified in women with darker skin. Hemangiomas and glomus tumors occur in one-third of women. A firm edema may develop on the face and extremities in the final months of pregnancy. Venous hypertension and varicosities of the lower limbs are common. Gingivitis, gum hypertrophy, and pyogenic granuloma are common in the oral cavity. The vaginal mucosa is also affected, showing a violaceous aspect, at times accompanied by varicosities of the vulva. Many gestational vascular changes regress spontaneously in the postpartum phase. Some vascular tumors may need to be treated with a vascular laser or intense pulsed light.

Blood Vessels↗

Granulomatous cutaneous centrofacial and meningocerebral amebiasis.

A 7-year-old, otherwise healthy Peruvian boy presented with a 3-month history of an indurated centrofacial plaque. Histologic examination revealed a granuloma containing free-living amebae tentatively identified as Balamuthia mandrillaris. The patient failed to respond to tentative treatment. He was admitted to the intensive care unit 7 months later with neurologic manifestations of granulomatous amebic encephalitis, which proved fatal. The difficulty in diagnosing this rare presentation of cutaneous amebiasis, the challenge of treating the condition, and the morbidity and high mortality associated with cerebral involvement are discussed.

Amebiasis↗

Collagen fibril arabesques in connective tissue disorders.

BACKGROUND: In various connective tissue disorders, collagen fibrils and elastic fibers may exhibit some ultrastructural abnormalities. OBJECTIVE: This electron microscopy study focused on collagen fibril orientation and unusual shapes in the dermis of Ehlers-Danlos syndrome (EDS) and related entities, including spontaneous cervical artery dissection syndrome and recurrent preterm premature rupture of fetal membranes syndrome. RESULTS: In addition to some abnormal fibril shapes typically found in these syndromes, other conformations (hook shaped, S shaped, ring shaped) that have not been illustrated previously in the literature were observed. CONCLUSION: The abnormal collagen fibril conformations observed in EDS and other related conditions characterized by tissue fragility likely affect both the internal cohesiveness of the bundles and the mechanobiologic properties of the tissue.

Adolescent↗

Oral antifungal-exacerbated inflammatory flare-up reactions of dermatomycosis : case reports and review of the literature.

Inflammatory flare-up reactions of some dermatomycoses, particularly those caused by zoophilic fungi, are typical and potentially severe adverse effects following the intake of some oral antifungals. However, this condition has not previously been reported with the most frequently used antifungals in dermatology, namely fluconazole, itraconazole, and terbinafine. In this report, we describe five patients, observed over a 10-year period, who presented with inflammatory exacerbations following oral antifungal therapy for dermatomycoses. We also review the literature on inflammatory reactions exacerbated by oral antifungal agents. Details of the patients' age, sex, occupation, and atopic background; the site of the lesion, its clinical and histologic features, and any systemic signs; the identity of the fungal pathogen; the antifungal agent taken by the patient; the time between drug intake and occurrence of the flare-up; the approach to management; and the outcome were documented for each patient. A PubMed literature search was also conducted, focusing on inflammatory exacerbations induced by griseofulvin, ketoconazole, itraconazole, fluconazole, and terbinafine. The patients were four farmers and one veterinarian (all male). All primary lesions were inflammatory dermatophytoses, including one kerion. Inflammatory exacerbation of the skin lesions started 12-24 hours after the intake of oral antifungals. Mild systemic changes, including slight fever and malaise, occurred in two cases. Itraconazole 400 mg/day was implicated as the causative agent in four cases and terbinafine 250 mg/day in one case. Mycologic cultures grew Trichophytonverrucosum in four cases. Antifungal treatment was discontinued in all patients. Oral and topical corticosteroids were administered to the two patients with systemic changes; the other three patients were treated with topical corticosteroids only. Two days after the onset of corticosteroids, lower doses of itraconazole (100 mg/day) and terbinafine (125 mg/day) were reintroduced. All lesions healed after 4-5 weeks. The PubMed search did not identify any articles that described inflammatory exacerbations of dermatomycoses induced by oral antifungals. Inflammatory flare-up of dermatomycoses is a rare but potentially severe cutaneous complication of oral antifungal use. Occupational contact with animals, inflammatory dermatomycoses, and zoophilic fungi represent common features in these patients. Although evidence-based data are not available, clinical experience shows that, in addition to antifungal therapy, topical and/or systemic corticosteroids are helpful to reduce the inflammatory reactions. The cases described in this article represent the first published report of oral antifungal-exacerbated inflammatory flare-up reactions of dermatomycosis in patients taking itraconazole or terbinafine.

Administration, Oral↗

Novel treatments for drug-induced toxic epidermal necrolysis (Lyell's syndrome).

Drug-induced toxic epidermal necrolysis (TEN) is a life-threatening disease characterized by extensive destruction of the epidermis. It apparently results from the formation of specific toxic drug metabolites by the keratinocytes. The mortality rate which averages 25-30% is mainly due to secondary septicemia, and to ionic and metabolic disturbances following loss of epidermal integrity. Apoptosis is the likely mechanism leading to massive keratinocyte death in TEN. Dysregulations in the tumor necrosis factor-alpha (TNF-alpha) pathway, CD95 system (Fas ligand, CD95L; Fas receptor, CD95R) and calcium homeostasis in the epidermis are involved in this apoptotic process. An active role has also been ascribed to T lymphocytes, macrophages and factor XIIIa-positive dermal dendrocytes. Despite progress, treatment of TEN remains controversial. In the past, systemic glucocorticoids were used in order to target the inflammatory reaction in TEN. However, there was no evidence for improvement of the healing process, while corticosteroids worsened the prognosis by increasing the risk of septicemia. Only a few cases have been treated with other drugs including cyclophosphamide, pentoxyfilline, thalidomide, anti-TNF-alpha antibodies and cyclosporin A. In the recent past, some TEN patients were treated with intravenous human immunoglobulins (IVIG). The rationale for such a treatment was to block the CD95 system on keratinocytes. The early promising clinical results of IVIG treatment in TEN were subsequently challenged. This review compares the effectiveness and drawbacks of the major drugs presently used in TEN treatment. Some future prospects in TEN management are also discussed.

Apoptosis↗

Immunohistochemical detection of incipient melanoma micrometastases. Relationship with sentinel lymph node involvement.

It is acknowledged that tumour thickness, ulceration and lymph node invasion are the most important prognostic factors for cutaneous melanomas. Other histopathological features may also be informative. The aim of this study was to ascertain whether immunohistochemical methods can improve the detection of satellite micrometastases in primary melanoma patients. In addition, the predictive value of cutaneous satellite micrometastases for sentinel lymph node involvement was evaluated. A total of 265 primary cutaneous melanomas and 68 of the respective sentinel nodes were studied using a panel of seven antibodies directed against melanocyte-related antigens. In 12.4% of the 265 cases, small satellite micrometastases were detected by immunohistochemistry. Sentinel lymph node metastases were found in 14% of the 68 cases. Invasion of the sentinel lymph node correlated with the presence of cutaneous satellite micrometastases. It is concluded that the presence of cutaneous satellite micrometastases may be an indication for the performance of sentinel lymph node biopsy, and this finding calls for a closer follow-up of these patients.

Adult↗

Immunohistochemical investigation of alpha1 (IV) and alpha5 (IV) collagen chains in a broad spectrum of melanocytic tumours.

BACKGROUND: Cells of melanocytic naevi and cutaneous malignant melanomas (MM) are surrounded by a basement membrane (BM). AIM: To scrutinize any difference between the deposits of alpha1 (IV) and alpha5 (IV) collagen chains in melanocytic naevi and MM. METHODS: A total of 27 common melanocytic naevi, 11 dysplastic naevi, 21 atypical naevi (melanocytomas) including Spitz and non-Spitz types, as well as 24 MM were studied. Their phenotypic and functional characteristics defined by immunohistochemistry using a panel of antibodies, including those directed to the alpha1 (IV), alpha3 (IV) and alpha5 (IV) collagen chains. RESULTS: Almost all naevi and half the melanocytomas exhibited a strong positivity for the alpha1 (IV) collagen chain. By contrast, the remaining melanocytomas and MM presented a heterogeneous staining pattern for the alpha1 (IV) collagen chain. One third of the naevi, 23% of the MM without cutaneous micrometastasis and 83% of MM with cutaneous micrometastasis showed discrete cytoplasmic positivity for the alpha5 (IV) collagen chain. All other melanocytic tumours were negative for this antibody. Rare MM cells in transepidermal migration were stained with the anti-alpha1 (IV) or alpha5 (IV) collagen chain antibodies. No immunoreactivity for the alpha3 (IV) collagen chain was disclosed in any of the samples. CONCLUSION: We report the expression of alpha1 (IV) and alpha5 (IV) collagen chains in naevi and MM. The inconsistent staining pattern for alpha1 (IV) collagen chain in phenotypically atypical melanocytomas and in MM highlight the heterogeneity in both cell differentiation and stroma-tumour interactions. This biological aspect may be related to neoplastic progression and influence metastatic potential.

Cell Communication↗