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Biomedical subjects

Jean-Hilaire Saurat

Publications and source records attributed to Jean-Hilaire Saurat.

At least 19 recordsLinked to original sources

Severe eczematous skin reaction after high-dose intravenous immunoglobulin infusion: report of 4 cases and review of the literature.

BACKGROUND: High-dose intravenous immunoglobulins (IVIGs) are increasingly used to treat inflammatory and/or autoimmune disorders. In dermatology, they provide therapeutic benefit in Kawasaki disease and certain cases of dermatomyositis. While most adverse effects following IVIG treatment are not severe, occasionally more severe adverse effects occur, including anaphylactic reactions and acute, usually transient, renal failure. OBSERVATIONS: We report 4 cases of a characteristic severe extensive eczematous reaction that occurred approximately 10 days after IVIG infusion for polyradiculoneuritis. In all cases, onset was characterized by dyshidrotic lesions on the palms, rapidly followed by pruriginous maculopapular lesions involving the whole body. All patients were treated with topical and/or systemic steroids, and complete resolution of skin lesions was observed within 1 month. To date, 33 cases of cutaneous rash following IVIG infusion have been reported in the literature, mostly in neurology journals, and the features are identical to those reported herein. CONCLUSIONS: Severe eczematous skin reaction with a characteristic initial localization to the palms and/or soles that then extends to the rest of the body is a rare but characteristic adverse effect of high-dose IVIG therapy. Although the precise mechanism of this cutaneous eruption remains to be elucidated, its occurrence within days of IVIG infusion, its characteristic distribution at onset, and its clinical course should be recognized by dermatologists.

Biopsy↗

An illustrative case of Muir-Torre syndrome: contribution of immunohistochemical analysis in identifying indicator sebaceous lesions.

BACKGROUND: Muir-Torre syndrome (MTS) is an autosomal dominant genodermatosis characterized by the association of at least 1 cutaneous sebaceous tumor and 1 internal malignancy, often arising in the gastrointestinal tract. It is secondary to germline mutations in DNA mismatch repair genes, mainly MLH-1 and MSH-2. OBSERVATIONS: We report the case of a 54-year-old man with a 2-year history of skin-colored papules clinically reminiscent of large sebaceous hyperplasias on the nose and back, but histologically diagnosed as sebaceous adenomas and epitheliomas. His family history was positive for colon cancer in the mother and 2 brothers. A colonoscopy done during the hospitalization revealed 2 sessile polyps in the left colon, both showing a low-grade dysplasia on the biopsy specimen. Immunohistochemical staining performed on the cutaneous and colic biopsy specimens revealed a lack of expression of MSH-2 and MSH-6. Genetic testing revealed microsatellite instability in the colon and cutaneous tumors. CONCLUSION: The immunohistochemical testing for MSH-2, MSH-6, and MLH-1 is useful for rapid identification of an underlying mismatch repair defect and early diagnosis of MTS.

Adenocarcinoma, Sebaceous↗

CD44 and hyaluronate expression in follicular mucinosis.

BACKGROUND: CD44 is a membrane glycoprotein and the major cell-surface receptor of hyaluronate (HA). Lack of CD44 expression in mouse epidermis leads to an abnormal HA accumulation in the dermis, indicating an important role of CD44 in local HA metabolism. Decrease of epidermal CD44 expression in patients of lichen sclerosus et atrophicus is potentially responsible for dermal deposition of HA in this disease. Stromal HA accumulation is associated with decreased or lost expression of CD44 in perifollicular solitary cutaneous myxoma, myxoid dermatofibroma, and dermatofibrosarcoma protuberans. METHODS: We examined the expression of CD44 and HA in the skin biopsy specimens of 10 patients with follicular mucinosis by using CD44-specific antibodies and biotinylated HA-binding protein (HABP), respectively. RESULTS: No difference of CD44 expression was observed in the follicular keratinocytes when compared with those of unaffected interfollicular epidermis. The follicular zones of mucin deposition were strongly positive for HA. A weak interkeratinocyte staining for HA was also observed in the interfollicular epidermis. However, HABP staining revealed a stronger reactivity in the follicular keratinocytes surrounding the mucin-accumulated areas compared to the interfollicular keratinocytes. CONCLUSION: Our results suggest an active secretion of HA by follicular cells in follicular mucinosis.

Adult↗

Production and clearance of cyclobutane dipyrimidine dimers in UV-irradiated skin pretreated with 1% pimecrolimus or 0.1% triamcinolone acetonide creams in normal and atopic patients.

BACKGROUND: Ultraviolet (UV)-induced pyrimidine dimers are an early step in skin carcinogenesis, which is accelerated in the setting of long-term immunosuppression with systemic calcineurin inhibitors. It is not known whether topical application of calcineurin inhibitors exposes to a similar risk. OBJECTIVE: To assess the formation and clearance of UV-induced dipyrimidine dimers in human epidermis treated with topical pimecrolimus as compared to topical steroid, vehicle and untreated control. METHODS: Pretreated buttock skin of 20 human volunteers with (10) or without (10) atopic dermatitis was exposed to two minimal erythema doses (MED) of simulated solar radiation. DNA was extracted from epidermis 1 and 24 h postirradiation. Pyrimidine dimers were visualized by immuno slot blots and quantified by chemoluminescence image analysis. RESULTS: One-hour postirradiation, pimecrolimus-treated epidermis contains less DNA damage as compared to untreated control, but there were no statistically significant differences between pimecrolimus, triamcinolone acetonide and vehicle. Dimer levels at 24 h postirradiation showed no significant differences between different treatments. CONCLUSION: Treatment with pimecrolimus cream, triamcinolone acetonide cream and vehicle is not associated with increased epidermal DNA damage at 1 and 24 h post-UV exposure.

Administration, Cutaneous↗

Retinoic acid synergistically enhances the melanocytotoxic and depigmenting effects of monobenzylether of hydroquinone in black guinea pig skin.

Monobenzylether of hydroquinone (MBEH) has long been utilized for the depigmentation therapy of patients with extensive vitiligo. In this approach, the normally pigmented areas surrounding vitiligo lesions are depigmented to achieve a uniform skin tone. One of the important disadvantages of MBEH therapy, however, is the resistance of a considerable number of vitiligo patients against the depigmenting effect of this agent. We have previously proposed that the glutathione-dependent cytoprotection of melanocytes can be impaired through the inhibition of the enzyme glutathione S-transferase by retinoic acid (RA). The combination of RA with melanocytotoxic agents could thus lead to increased susceptibility of melanocytes to such compounds. In this study we have shown, for the first time, that the melanocytotoxic and depigmenting effects of MBEH are synergistically enhanced when it is combined with RA. The treatment of black guinea pig skin with RA (0.025%) alone induced no significant changes in the number of epidermal melanocytes and no skin depigmentation. On the other hand, MBEH (10%) produced mild to moderate skin depigmentation and reduced the average number of melanocytes from 76 (+/-5)/field (magnification: x 40) in control sites, to 42 (+/-6)/field in the depigmented skin. The RA (0.025%)-MBEH (10%) combination, however, produced a complete degree of depigmentation in the majority of treated sites after 10 days of application and reduced the average number of melanocytes to only 6 (+/-6)/field. RA-MBEH combination serves as a very potent skin depigmenting formula and now awaits future assessments of its potential use for the treatment of extensive vitiligo.

Animals↗

Clinical Experience Acquired with Raptiva (CLEAR) trial in patients with moderate-to-severe plaque psoriasis: results from extended treatment in an international, Phase III, placebo-controlled trial.

BACKGROUND: The 12-week, double-blind, placebo-controlled, first-treatment (FT) CLEAR trial period demonstrated the efficacy/safety of efalizumab in moderate-to-severe plaque psoriasis, including refractory or contraindicated patients unsuitable for other systemic treatments. This study assessed the efficacy/safety of open-label extended treatment (up to 24 weeks' continuous treatment) in patients not achieving > or =75% improvement in Psoriasis Area and Severity Index (PASI-75) at week 12 of the FT period. Time to relapse after treatment cessation, and efficacy/safety of 12 weeks' open-label re-treatment in patients achieving PASI-75 at week 12 FT were also assessed. PATIENTS AND METHODS: Patients with PASI-75 at week 12 FT were observed without treatment until relapse, then re-treated with open-label efalizumab (1.0 mg/kg/week for 12 weeks). Others received open-label extended treatment without intervening observation. RESULTS: Among efalizumab-treated patients (n = 308) who had < 75% PASI improvement at week 12 FT, extended treatment led to PASI-75 in 26.6%. Among patients with between > or = 50 and < 75% PASI improvement at week 12 FT (n = 118), 47.5% improved to PASI-75 with extended treatment. For patients achieving PASI-75 at week 12 FT (n = 164), median time to relapse was 58 days. Re-treatment after relapse led to mean PASI improvement of 62.3% from study baseline (n = 145). Safety results were consistent with previous studies, with no new safety concerns. CONCLUSIONS: These results demonstrate additional benefit of continuing efalizumab. Re-treatment re-established disease control in patients with PASI-75 who relapsed following treatment cessation. The safety profile remained consistent with that seen at 12 weeks.

Administration, Topical↗

Hyaluronate fragments reverse skin atrophy by a CD44-dependent mechanism.

BACKGROUND: Skin atrophy is a common manifestation of aging and is frequently accompanied by ulceration and delayed wound healing. With an increasingly aging patient population, management of skin atrophy is becoming a major challenge in the clinic, particularly in light of the fact that there are no effective therapeutic options at present. METHODS AND FINDINGS: Atrophic skin displays a decreased hyaluronate (HA) content and expression of the major cell-surface hyaluronate receptor, CD44. In an effort to develop a therapeutic strategy for skin atrophy, we addressed the effect of topical administration of defined-size HA fragments (HAF) on skin trophicity. Treatment of primary keratinocyte cultures with intermediate-size HAF (HAFi; 50,000-400,000 Da) but not with small-size HAF (HAFs; <50,000 Da) or large-size HAF (HAFl; >400,000 Da) induced wild-type (wt) but not CD44-deficient (CD44-/-) keratinocyte proliferation. Topical application of HAFi caused marked epidermal hyperplasia in wt but not in CD44-/- mice, and significant skin thickening in patients with age- or corticosteroid-related skin atrophy. The effect of HAFi on keratinocyte proliferation was abrogated by antibodies against heparin-binding epidermal growth factor (HB-EGF) and its receptor, erbB1, which form a complex with a particular isoform of CD44 (CD44v3), and by tissue inhibitor of metalloproteinase-3 (TIMP-3). CONCLUSIONS: Our observations provide a novel CD44-dependent mechanism for HA oligosaccharide-induced keratinocyte proliferation and suggest that topical HAFi application may provide an attractive therapeutic option in human skin atrophy.

Adult↗

[State of the art in melanoma diagnosis].

The incidence of melanoma has been rising over the ten last years and is increasing faster than for other cancers. According to informations of the national cancer registry, there are approximately 1500 new cases of melanoma per year in Switzerland. The incidence for melanoma is 7.5 new cases per 100000 inhabitants per year for Europe, 17.9 for Switzerland and 24.7 in the Canton of Geneva. Often the diagnosis is made in advanced stages which is the reason why melanoma is responsible for more than 90% of all skin cancer related deaths. In this context screening and early diagnosis are particularly important. In this article we are going to review the different established techniques for non invasive melanoma diagnosis as well as some very promising approaches which are still at an experimental stage.

Dermoscopy↗

Telemedical wound care using a new generation of mobile telephones: a feasibility study.

BACKGROUND: Leg ulcers are an important cost factor in health care systems. It has been shown that a telemedical wound care consultation can improve quality of care and help reduce costs. In this study, we evaluated the feasibility of telemedical wound care using a new generation of mobile telephones with integrated cameras. OBSERVATIONS: Three physicians separately evaluated 61 leg ulcers for the following 9 variables: epithelialization, fibrin, necrosis, and granulation tissue at the center and normal border, erythema, cyanosis, eczema, and hyperpigmentation at the periphery. One physician performed the face-to-face consultation (gold standard), and 2 others performed the remote evaluation. The image was obtained with the mobile telephone and immediately sent via e-mail. To measure the agreement of the evaluation among the 3 physicians, we used Cohen kappa statistics. Overall, the agreement between the remote and face-to-face evaluations was very good, with kappa values of up to 0.94 The image quality was judged to be good in 36 cases (59%) and very good in 12 (20%). The participants felt comfortable making a diagnosis based on the pictures in 50 cases (82%). CONCLUSION: Although this study was performed with the first generation of these devices, we were able to demonstrate the feasibility of such a telemedical wound care consultation.

Adult↗

Dermoscopy of pigmented skin lesions.

Dermoscopy is an in vivo method for the early diagnosis of malignant melanoma and the differential diagnosis of pigmented lesions of the skin. It has been shown to increase diagnostic accuracy over clinical visual inspection in the hands of experienced physicians. This article is a review of the principles of dermoscopy as well as recent technological developments.

Algorithms↗

Retinoic acid and its 4-oxo metabolites are functionally active in human skin cells in vitro.

Retinoic acid exerts a variety of effects on gene transcription that regulate growth, differentiation, and inflammation in normal and neoplastic skin cells. Because there is a lack of information regarding the influence of metabolic transformation of retinoids on their pharmacologic effects in skin, we have analyzed the functional activity of all-trans-, 9-cis-, and 13-cis-retinoic acid and their 4-oxo-metabolites in normal human epidermal keratinocytes (NHEKs) and dermal fibroblasts using gene and protein expression profiling techniques, including cDNA microarrays, two-dimensional gel electrophoresis, and MALDI-MS. It was previously thought that the 4-oxo-metabolites of RA are inert catabolic end-products but our results indicate instead that they display strong and isomer-specific transcriptional regulatory activity in both NHEKs and dermal fibroblasts. Microarray and proteomic analyses identified a number of novel genes/gene products that are influenced by RA treatment of NHEKs or fibroblasts, including genes for enzymes catalyzing biotransformation of retinoids, corticosteroids, and antioxidants and structural and transport proteins known to be essential for homeostasis. Our results expand current knowledge regarding retinoic acid action within skin cells and the target tissue/cell regulatory systems that are important for modulating the physiological and pharmacological effects of this important class of dermatological drugs.

Alitretinoin↗

Proposed mechanisms of action for retinoid derivatives in the treatment of skin aging.

Skin aging (intrinsic aging) and photoaging (extrinsic aging) involve a similar process that leads to the typical creased appearance of the skin, with the progressive loss of its physical and biologic properties. Photoaging is a premature skin aging caused by long-term exposure to the ultraviolet B radiations of the sun, and is more frequently associated to skin cancer than intrinsic aging. Retinoids are natural and synthetic vitamin A derivatives. They are lipophilic molecules and penetrate the epidermis easily. Their biologically active forms can modulate gene expression by binding to nuclear receptors and then to specific DNA sequences. Because of their ability to modulate genes involved in cellular differentiation and proliferation, they appear as good candidates to treat and prevent photoaging. Hyaluronate and collagen, two major constituents of the dermis, are progressively decreased and altered during aging. Various retinoids were shown to increase their synthesis and concentration in the skin and reduce their rate of degradation. Furthermore, retinoids share a common chemical structure containing several conjugated double bonds that enable them to trap free radicals and absorb UV radiations from the sun, thereby protecting cellular targets such as DNA, lipid membranes, or proteins by preventing direct photochemical damage or UV-induced oxidative stress. Therefore, retinoids may be beneficial in treating skin aging and photoaging because of their biologic, chemical, and physical properties, which act at several levels.

Journal Article↗

Three-dimensional reconstruction of basal cell carcinomas.

BACKGROUND: Basal cell carcinoma (BCC) is the most common type of skin cancer. One of the main problems with BCC is the risk of local recurrence of the tumor after treatment. This is mainly due to its irregular outgrowths, which cannot be detected clinically. OBJECTIVE: To better understand the tumor morphology and growth pattern of BCC, we tried to develop a method that provides a precise three-dimensional model of the tumor. METHODS: Because Mohs surgery provides the best overview of the tumor and the tumor margins (both lateral and in depth), the reconstruction was based on slides from Mohs surgery. After digitization and processing of the slides, the tumor was then surrounded by a Mohs surgeon on a computer screen. These selections (lines) were used for a three-dimensional reconstruction of the tumor using MedSurf3D software. RESULTS: This method allows three-dimensional reconstruction of any given BCC. The MedSurf3D software enables visualization of a three-dimensional model of the tissue, which is removed during the surgical procedure. CONCLUSIONS: Three-dimensional reconstruction is a fascinating tool that might improve our understanding of the behavior, growth pattern, and tumor morphology of BCCs. This technique might also be useful in other fields of cutaneous oncology, such as the calculation of the tumor volume of melanomas.

Basal Cell Carcinoma↗