[Dermatology, cosmetology and aesthetic medicine].
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Cosmetic Techniques↗
Biomedical subjects
L Dubertret
Publications and source records attributed to L Dubertret.
Refined localization of the gene for Clouston syndrome (hidrotic ectodermal dysplasia) in a large French family.
Hidrotic ectodermal dysplasia (HED) or Clouston syndrome is a rare autosomal dominant disorder characterized by nail dystrophy, alopecia and palmoplantar hyperkeratosis, which maps to chromosome 13q11-q12.1. We confirmed linkage of HED to this region in a large French family. To define the critical region for HED, detailed haplotypes were constructed with new pericentromeric polymorphic markers. A recombination event in the family indicates that the HED locus maps centromeric to D13S1832. Our French family does not share a common haplotype with other pedigrees previously published (particularly French-Canadian), indicating that the mutations in these families are likely to be of different origin.
Chromosomes, Human, Pair 13↗
[Thalidomide and thrombosis].
BACKGROUND: Teratogenicity and neuropathy are the well known serious side effects induced by thalidomide. We describe 5 cases of thrombotic events occurring within a brief delay after the onset of thalidomide in a manner that suggests that thalidomide could have acted as a precipiting or as a starting factor in these events. OBSERVATIONS: Five patients including 4 patients with lupus erythematosus (1 discoid lupus, 1 subacute lupus and 2 systemic lupus erythematosus) and one patient with a severe atopic dermatitis, all without previous history of vascular events, developed an arterial thrombosis (2 cases) or a venous thrombosis (3 cases), severe in 4 cases, few days or weeks after the onset of thalidomide treatment (50 to 100 mg daily). DISCUSSION: All the patients had risk factors of thrombosis: the presence of antiphospholipids and/or anticardiolipin antibodies in lupus erythematosus patients and a trauma in the atopic case. However the absence of a previous story of thrombosis, its rapid occurrence after the onset of thalidomide and its severity are intriguing. In addition, recent studies demonstrate that thalidomide has various effects that would act, among other things, on angiogenesis. Thus, we think that a doubt exists on a negative effect of thalidomide in thrombosis risk factors patients and that this hypothesis has to be confirmed.
Adult↗
[Renal function during long-term cyclosporin treatment of psoriasis].
INTRODUCTION: The goal of this retrospective study was to evaluate the effects of cyclosporin A on renal function in patients treated for five years or more. PATIENTS AND METHODS: Two hundred twenty-four psoriasis patients were treated with cyclosporin at St. Louis Hospital, in Paris, from 1988 to 1997. Eleven patients (5 p. 100 of the total) took cyclosporin for at least five years. Nine case histories were available for the analysis. RESULTS: The group studied consisted of eight men and one woman, ranging in age from 28 to 48 with an average age of 38 years. The average cyclosporin dosage was 3.6 mg/kg/day (2.0-5.0 mg/kg/day). The changes in renal function were not significant as compared to the baseline level. The patients did not show persistent increases of serum creatinine more than 30 p. 100 of the pre-treatment value. Two patients had to discontinue treatment after 6 years because of a 20 p. 100 decrease in glomerular filtration rate. DISCUSSION: Previous studies have shown that cyclosporin A is not a suitable long-term continuous monotherapy for psoriasis. However, with precise and regular monitoring of kidney function, a minority of patients can benefit from prolonged treatment without experiencing side effects.
Adult↗
P16 UV mutations in human skin epithelial tumors.
The p16 gene expresses two alternative transcripts (p16alpha and p16beta) involved in tumor suppression via the retinoblastoma (Rb) or p53 pathways. Disruption of these pathways can occur through inactivation of p16 or p53, or activating mutations of cyclin dependant kinase 4 gene (Cdk4). We searched for p16, Cdk4 and p53 gene mutations in 20 squamous cell carcinomas (SSCs), 1 actinic keratosis (AK), and 28 basal cell carcinomas (BCCs), using PCR-SSCP. A deletion and methylation analysis of p16 was also performed. Six different mutations (12%) were detected in exon 2 of p16 (common to p16alpha and p16beta), in five out of 21 squamous lesions (24%) (one AK and four SCCs) and one out of 28 BCCs (3.5%). These included four (66%) ultraviolet (UV)-type mutations (two tandems CC : GG to TT : AA transitions and two C : G to T : A transitions at dipyrimidic site) and two transversions. P53 mutations were present in 18 samples (37%), mostly of UV type. Of these, only two (one BCC and one AK) harboured simultaneously mutations of p16, but with no consequence on p16beta transcript. Our data demonstrate for the first time the presence of p16 UV induced mutations in non melanoma skin cancer, particularly in the most aggressive SCC type, and support that p16 and p53 are involved in two independent pathways in skin carcinogenesis.
Alternative Splicing↗
UV-A-induced decrease in nuclear factor-kappaB activity in human keratinocytes.
Previous reports have demonstrated an increase in nuclear factor-kappaB (NF-kappaB) activity in response to UV radiation. These studies have essentially focused on the DNA-damaging fraction of solar UV radiation (UV-B and UV-C). In contrast, the effects of UV-A radiation (320-400 nm) on NF-kappaB are not well known. In this study, we present evidence that UV-A radiation induces a marked decrease in NF-kappaB DNA-binding activity in NCTC 2544 human keratinocytes. In addition, NCTC 2544 keratinocytes pretreated with UV-A fail to respond to NF-kappaB inducers. Moreover, UV-A radiation induces a decrease in NF-kappaB-driven luciferase reporter gene expression in NCTC 2544 keratinocytes. The expression of the gene encoding IkappaBalpha (IkappaB is the NF-kappaB inhibitor), which is closely associated with NF-kappaB activity, is also reduced (3-fold) upon UV-A treatment. Our results indicate that the UV-A-induced decrease in NF-kappaB DNA-binding activity is associated with a decrease in the levels of the p50 and p65 protein subunits. This is the first evidence that an oxidative stress, such as UV-A radiation, may induce a specific decrease in NF-kappaB activity in mammalian cells, probably through degradation of NF-kappaB protein subunits. These findings suggest that UV-A could modulate the NF-kappaB-dependent gene expression.
Antioxidants↗
Immune-mediated destruction of melanocytes in halo nevi is associated with the local expansion of a limited number of T cell clones.
The beta-chain repertoire of the T cells that infiltrate spontaneously regressing nevi (the halo nevus phenomenon) was studied. In addition to the infiltration of the halo nevi by cutaneous lymphocyte-associated Ag-positive lymphocytes, oligoclonal expansion of T cells was observed in all halo nevi of all patients. T cells using the same TCR beta-chain were observed in distinct halo nevi of the same patient but not in his peripheral blood, demonstrating a local expansion of common clones that are most likely activated by the Ag(s) shared by independent halo nevi of the same patient.
Amino Acid Sequence↗
Leg ulcers and hydroxyurea: forty-one cases.
BACKGROUND: Hydroxyurea is an antitumor agent used to treat chronic myeloproliferative disorders. Leg ulcerations have been reported in patients undergoing long-term hydroxyurea therapy for myeloproliferative diseases. To better define this dermatological adverse effect of hydroxyurea therapy and to try to understand the pathophysiological process of this disease, we collected medical information for such patients in a multicenter retrospective study. OBSERVATIONS: Forty-one patients (mean age, 67 years) developed leg ulcerations while undergoing hydroxyurea therapy (mean therapy duration, 5 years). The sex ratio was 1, and there was no underlying vascular disease. Hematologic abnormalities were identified. Complete recovery from the ulcerations occurred quickly after withdrawal of treatment in 33 (80%) of the cases. CONCLUSIONS: This longest-reported series of patients confirms the role of hydroxyurea therapy in the onset of leg ulcerations. Healing or improvement requires cessation of treatment. Cutaneous atrophy and impaired wound healing may explain the relationship between hydroxyurea and leg ulcers. In addition, the megaloblastic erythrocytes resulting from the presence of hydroxyurea may circulate poorly through the capillary network. A prospective study in hematologic centers would be valuable.
Adult↗
Pure ocular cicatricial pemphigoid. A distinct immunopathologic subset of cicatricial pemphigoid.
OBJECTIVE: To determine whether ocular cicatricial pemphigoid (OCP) may represent a distinct immunopathologic disease when it is pure ocular cicatricial pemphigoid (POCP) (e.g., only confined to the conjunctiva) or when it is associated with skin or extraocular mucous membrane lesions or both (OCP+). DESIGN: Prospective, immunologic, and immunopathologic study with special emphasis on direct immunoelectron microscopy. PARTICIPANTS: Six patients with POCP and seven patients with OCP+. INTERVENTION: After informed consent was obtained, a conjunctival biopsy was performed in all patients. Skin and extraocular mucosa biopsy specimens were harvested in selected cases only. MAIN OUTCOME MEASURES: Results of direct immunofluorescence and direct immunoelectron microscopy without freezing on conjunctival and skin biopsy specimens, indirect immunofluorescence, and Western immunoblotting analysis were analyzed. RESULTS: Results of direct immunoelectron microscopic examination of the conjunctiva showed the presence of immune deposits in the upper lamina lucida of the basement membrane zone in the six patients with POCP, whereas the immune reactants were located in the lower part of the lamina lucida and in the lamina densa of the basement membrane zone (conjunctiva, buccal mucosa, and skin) in the seven patients with OCP+. Direct immunofluorescence was positive in the biopsy specimens of three patients with POCP (50%) and the seven patients with OCP+ (100%). Results of indirect immunofluorescence study showed circulating autoantibody levels only in two patients with OCP+, and results of Western immunoblot analysis were negative. CONCLUSIONS: Results of direct immunoelectron microscopic examination of the conjunctiva support the hypothesis that POCP may be a disease entity distinct from mucocutaneous cicatricial pemphigoid.
Aged↗
Low doses of ultraviolet A radiation stimulate adhesion of human dermal fibroblasts by integrins in a protein kinase C-dependent pathway.
In this work, we have studied the modulation of fibroblast-extracellular matrix interactions by physiological doses of ultraviolet A (UV-A) radiation using an adhesion assay on collagen. We have shown that low doses of UV-A (20 kJ/m2) stimulate fibroblast adhesion while higher doses (100 and 200 kJ/m2) inhibit it. By measurement of the thiobarbituric acid reactive substances (TBARS) and use of the chain-breaking antioxidant vitamin E, no role of lipid peroxidation can be detected in these effects. By incubating fibroblasts with a specific protein kinase C (PKC) inhibitor, GF109203X, we have demonstrated that the stimulation of the adhesion by low doses of UV-A involves, at least in part, a PKC-dependent mechanism. In addition, using function-blocking antibodies of alpha 1, alpha 2 or alpha 5 integrin chains involved in extracellular matrix anchorage, we have shown that they decrease the stimulation of adhesion following low doses of UV-A radiation, demonstrating the involvement of these three integrin chains in this UV-A effect. In parallel, 20 kJ/M2 of UV-A are found to rapidly stimulate membrane expression of alpha 1, alpha 2 and alpha 5 integrin chains. This work, which underlines the involvement of integrins in UV-A effects, contributes to the evaluation of the mechanisms by which cell-matrix interactions modulate cell behaviour.
Adolescent↗
Lamellar ichthyosis: further narrowing, physical and expression mapping of the chromosome 2 candidate locus.
Lamellar ichthyosis (LI) is an autosomal recessive genodermatosis which has been shown to be both clinically and genetically heterogeneous. Keratinocyte transglutaminase (or transglutaminase 1: TGM1) has been demonstrated to be the disease-causing gene in some families, whilst in others, a second unidentified LI gene was mapped to chromosome 2q33-35 (ICR2B locus). In this study, we present a physical map that encompasses the ICR2B locus, including the mapping of new microsatellite markers. Based on this new map, genotyping additional families highly suggests a reduction in size of the candidate interval. The final interval is covered by a single yeast artificial chromosome (937-H-3) which is 2.2Mb in length. Fine mapping of potential candidate transcripts was also focused on this region.
Chromosomes, Artificial, Yeast↗
Minocycline for the treatment of cutaneous silicone granulomas.
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Anti-Bacterial Agents↗
A prospective coagulation study including resistance to activated protein C and mutations in factors V and II in venous leg ulcers.
Hypercoagulable states have been reported to be associated with venous leg ulcers. In an attempt to investigate the prevalence of hypercoagulable states in patients with venous leg ulcers, we performed a prospective case-control study for the presence of coagulation defects in such patients, including resistance to activated protein C (APC), factor V Leiden mutation and a newly described mutation in factor II. Results were compared with those obtained in a control group. APC resistance was found in four of 33 patients tested, but only one was found to be heterozygous for the factor V Leiden mutation. Factor II mutation was found in two of 30 patients tested. Our findings show that the prevalence of coagulation abnormalities is not different in patients with venous leg ulcers from controls in our study, suggesting that only selected patients with venous ulcers and a history of recurrent deep venous thrombosis should be investigated for the presence of coagulation defects.
Activated Protein C Resistance↗
What is the best way to define the antimelanocyte T cell repertoire?
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Antibodies↗
Contact allergens, but not irritants, alter receptor-mediated endocytosis by human epidermal Langerhans cells.
Allergic contact dermatitis is a T-cell-mediated inflammation, induced by contact with sensitizers and occurring through the release of epidermal cytokines and the activation of epidermal Langerhans cells (LCs). The aim of this study was to analyse early events of LC activation induced either by contact allergens or by irritants devoid of any contact allergenic properties. in order to obtain an in vitro method to discriminate between these two groups of molecules. Various contact sensitizers and irritants were studied for their effects on the endocytosis of major histocompatibility complex class II (MHC-II) molecules by freshly-isolated human epidermal LCs. As observed by flow cytometry, a spontaneous decrease in the surface expression of MHC-II (HLA-DR) molecules, linked to spontaneous internalization of the MHC-II molecules by LCs, was obtained by moving freshly-isolated LCs from 4 degrees C to 37 degrees C. Pre-incubation of LCs with either sensitizers or irritants increased the spontaneous internalization of HLA-DR molecules with a similar magnitude, but no clear discrimination between sensitizer and irritant effects was obtained by flow cytometry analysis. In contrast, confocal microscopy enabled discrimination between the effects of sensitizers and irritants: sensitizer-treated samples showed internalized HLA-DR molecules aggregated in large vesicles with very bright fluorescence; irritant-treated samples were not different from untreated controls and showed compact HLA-DR molecules in small vesicles with diffuse fluorescence, and mostly localized in the submembranous zone. Electron microscopy demonstrated that sensitizer-treated LCs internalized HLA-DR molecules preferentially in lysosomes collected near the nucleus, whereas the irritant-treated and non-treated LCs internalized these molecules in the prelysosomes only near the cell membrane. We conclude that contact allergens and irritants induce distinct patterns of HLA-I)R endocytosis, which may be useful for the development of in vitro screening tests.
Adult↗
Chronic radiodermatitis following cardiac catheterisation: a report of two cases and a brief review of the literature.
Cardiac angiography produces one of the highest radiation exposures of any commonly used diagnostic x ray procedure. Recently, serious radiation induced skin injuries have been reported after repeated therapeutic interventional procedures using prolonged fluoroscopic imaging. Two male patients, aged 62 and 71 years, in whom chronic radiodermatitis developed one to two years after two consecutive cardiac catheterisation procedures are reported. Both patients had undergone lengthy procedures using prolonged fluoroscopic guidance in a limited number of projections. The resulting skin lesions were preceded, in one case, by an acute erythema and took the form of a delayed pigmented telangiectatic, indurated, or ulcerated plaque in the upper back or below the axilla whose site corresponded to the location of the x ray tube during cardiac catheterisation. Cutaneous side effects of radiation exposure result from direct damage to the irradiated tissue and have known thresholds. The diagnosis of radiation induced skin injury relies essentially on clinical and histopathological findings, location of skin lesions, and careful medical history. Interventional cardiologists should be aware of this complication, because chronic radiodermatitis may result in painful and resistant ulceration and eventually in squamous cell carcinoma.
Aged↗
Efficacy and safety of mizolastine 10 mg in a placebo-controlled comparison with loratadine in chronic idiopathic urticaria: results of the MILOR Study.
BACKGROUND: Mizolastine is a novel histamine H1-antagonist registered in Europe for the management of allergic rhinitis and urticaria. OBJECTIVES: To compare the clinical efficacy and safety of mizolastine with loratadine and placebo in patients with chronic idiopathic urticaria (CIU). METHODS: A multicentre, double-blind, parallel group study was designed in which 247 patients with CIU were randomised after a 1-week placebo run-in period to 10 mg daily mizolastine (n = 88), 10 mg daily loratadine (n = 79), or placebo (n = 80) for a 4-week treatment period. RESULTS: Mizolastine and loratadine both relieved symptoms of CIU. After 2 weeks' treatment, the severity of pruritus (visual analogue score (VAS) assessed by patients) decreased significantly in both the mizolastine and loratadine groups compared with placebo (mizolastine: -36.7 mm, P = 0.0001; loratadine: -29.8, P = 0.0071; placebo: -16.3); this improvement with both active treatments was maintained throughout the treatment period, the difference being significant only for the mizolastine group (P = 0.0090). Both active treatments were also associated with reduced weekly episodes of urticaria compared with placebo, which was significant after 2 weeks' treatment (mizolastine: 7.9 episodes, P = 0.0061; loratadine: 8.3, P = 0.0221; placebo: 13.3). Angioedema was improved to a clinically significant extent with mizolastine, and loratadine compared with placebo in those patients who had this symptom before treatment. Overall tolerability of both treatments was similar to placebo, and there were no clinically relevant effects on cardiac repolarisation with either mizolastine or loratadine. CONCLUSION: Mizolastine (10 mg daily) is confirmed as an effective and well tolerated agent, comparable to loratadine and superior to placebo, for the management of CIU. Mizolastine acted as rapidly as loratadine in improving urticarial symptoms from the first day of treatment.
Adult↗
[Information, misinformation and photo-education].
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Health Education↗