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B Guillot

Publications and source records attributed to B Guillot.

At least 19 recordsLinked to original sources
PubMed2006

Simulated structural and thermal properties of glassy and liquid germania.

Structural, dynamical, and thermal properties of germanium dioxide are investigated with classical molecular dynamics simulations from the amorphous to the liquid state. Pair correlation functions and coordination numbers are computed under pressure change and show the progressive conversion of the tetrahedral network into an octahedral network, in agreement with experiments. The thermodynamical behavior of the liquid is investigated by means of an equation of state that allows a precise estimation of the compressibility. At low temperature, the diffusion constant D shows an Arrhenius law that progressively deviates when the temperature is increased. The overall comparison with simulated silica permits finally to outline not only the differences in the physical behavior of these two similar systems but also to stress the limitation of the employed germania potential.

Journal Article↗
PubMed2006

[Macrocephaly-cutis marmorata telangiectatica congenita].

BACKGROUND: Macrocephaly-cutis marmorata telangiectatica congenita is a multiple congenital anomaly/mental retardation syndrome described in 1997 in children with macrocephaly, cutis marmorata telangiectatica congenita and several other abnormalities. CASE REPORT: A six month-old boy was seen for hyperplasia of the right side of the body. Clinical examination disclosed overgrowth, macrocephaly, a generalized reticulated, blue-violet vascular network, partial bilateral syndactyly between the 2nd and 3rd toes, and several superficial capillary malformations. Psychomotor development was normal. Brain MRI showed enlargement of the right lateral ventricle and hemisphere in relation to the left side but without malformation. Radiological examination of the skeleton showed asymmetry of the limbs. DISCUSSION: The patient reported herein presented macrocephaly-cutis marmorata telangiectatica congenita syndrome characterized by macrocephaly and more than two of the main reported findings comprising cutis marmorata, superficial vascular anomaly, syndactyly and asymmetry. We set out the major components of this polymalformative syndrome that are rarely reported in the dermatologic literature.

Abnormalities, Multiple↗
PubMed2006

[Aggressive T cytotoxic CD8+ epidermotropic cutaneous lymphoma: a case in a patient with Steinert's myotonic dystrophy].

INTRODUCTION: Primary cutaneous "aggressive" CD8-positive epidermotropic cytotoxic T-cell lymphoma is a rare subset of cutaneous cytotoxic T/NK lymphomas that clearly differs from mycosis fungoides, whether CD4+ or CD8+, by the presence of rapidly evolving tumoral cutaneous lesions, foci of keratinocytes necrosis, a cytotoxic T phenotype and a poor prognosis. CASE REPORT: A 33-year-old man with Steinert's myotonic dystrophy was referred for evaluation of rapidly worsening cutaneous tumors along with marked deterioration of general status. Clinical, histological and immunohistological data led to the diagnosis of primary cutaneous CD8+ epidermotropic cytotoxic T-cell lymphoma. CHOP chemotherapy was effective despite cardiac toxicity in the setting of Steinert's dystrophy, but the patient relapsed and died of pulmonary sepsis after chemotherapy was resumed. DISCUSSION: The treatment of primary cutaneous epidermotropic CD8+ cytotoxic T-cell lymphoma is not codified. CHOP chemotherapy is usually the first-line therapy but relapses are frequent with median survival of no more than 34 months. In our patient, an additional difficulty was the cardiac toxicity of cytostatic drugs linked to the myopathy which prevented the use of high dosages, requiring a change of therapeutic regimen.

Adult↗
PubMed2006

Chronic cutaneous lupus flare induced by systemic 5-fluorouracil.

5-Fluorouracil is an antineoplastic antimetabolite responsible for a variety of cutaneous reactions. We report a case of chronic cutaneous lupus flare related to systemic 5-fluorouracil administration for breast cancer in a patient with documented history of chronic cutaneous lupus.

Adenocarcinoma↗
PubMed2006

The presence of dominant T-cell clones in peripheral blood of patients with collagen vascular disorders: a prospective study of 97 cases.

BACKGROUND: T-lymphocyte dysfunction has been seldom investigated in collagen vascular disorders. The search for dominant T-cell clones has been scarcely reported, although the presence of such clones might be expected in disorders showing immune responses directed against a variety of autoantigens. OBJECTIVES: We conducted a systematic search for dominant T-cell clones in peripheral blood in patients with collagen vascular disorders. Patients and methods Ninety-seven patients with collagen vascular disorders were studied (7 cutaneous and 38 systemic lupus erythematosus; 8 multiple morphea; 12 regional scleroderma; 32 systemic sclerosis of the CREST type). A dominant T-cell clone was searched for in peripheral blood by polymerase chain reaction targeting the T-cell receptor gamma chain followed by a size analysis of amplified fragments. Peripheral blood from patients with nonlymphocyte-dependent disorders and matched by age and sex was assessed in the same conditions. Results in both groups were compared using nonparametric statistical tests. RESULTS: Overall, a circulating dominant T-cell clone was found in 52% of patients compared with 16.9% in controls. More precisely, such a dominant clone was present in 43% and 37% of cutaneous and systemic lupus erythematosus, respectively, in 75% of multiple morphea, 75% of regional scleroderma and 60% of CREST syndrome patients. The percentages in all subsets of patients were significantly higher than in the control group. CONCLUSIONS: The presence of a dominant T-cell clone in peripheral blood is significantly more frequent in collagen vascular disorders than in controls, especially in patients with scleroderma, whatever the clinical subset, which suggests T-cell involvement in the immune response dysfunction in these diseases classically characterized by disturbances of B lymphocytes. The relevance of such a dominant clone regarding diagnosis, pathomechanisms, long-term outcome and visceral prognosis of these diseases as well as therapeutic decisions remains to be evaluated.

Adolescent↗
PubMed2005

[Connubial contact dermatitis to an inhaled corticosteroid].

BACKGROUND: Inhaled corticosteroids are widely used in allergic asthma and rhinitis. They are most often used alone or sometimes in association. Allergic side-effects of inhaled corticosteroids are less frequent than those of topical corticosteroids. We report a case of a connubial dermatitis to a budesonide spray. OBSERVATION: A 3-year old boy was treated for asthma by budesonide (Pulmicort) and terbutaline (Bricanyl) aerosols with an inhalation chamber (Babyhaler). From the fourth day of treatment onwards, his mother had swollen and itchy lesions on the face with conjunctivitis several hours after the administration of the corticosteroids using the inhalation chamber. The last eruptions were marked by extensive lesions. The patient reported a worsening of her eruption when she was treated with a desonide cream (Tridesonit). Prick-tests conducted later on confirmed the contact allergy to budesonide and Pulmicort spray. They were also positive for Tridesonit cream and triamcinolone acetonide. Repeated open application tests with a 17-butyrate hydrocortisone cream (Locoid) for three weeks remainded negative. DISCUSSION: Our observation is original: allergic contact dermatitis to inhaled corticosteroids is rare, the clinical presentation mimicked angioedema although it was a delayed-type hypersensitivity, hypersensitivity was limited to group B corticosteroids and it was in fact a connubial contact dermatitis.

Administration, Inhalation↗
PubMed2005

[Trisomy 20 mosaicism revealed by pigmentary mosaicism of the Ito-type].

INTRODUCTION: Ito hypomelanosis-type pigmentary mosaicism is characterized by congenital pigmentation disorders along Blaschko's lines. We report a case of Ito-type pigmentary mosaicism associated with a congenital growth hormone deficiency having revealed trisomy 20 mosaicism. OBSERVATION: A 4 year-old boy presented with congenital pigmentation disorders. His history was marked by: inter-uterine delayed growth of unknown etiology, a dysmorphic syndrome, psychomotor retardation with speech problems, right cryptorchidia and an isolated, idiopathic, congenital growth hormone deficiency that had been treated with recombinant somatropine since the age of three. The clinical examination revealed alternating hypo and hyper-pigmented maculae with linear distribution on the limbs and in "twirls" on the trunk following Blaschko's lines. The blood karyotype was normal, the karyotype on fibroblasts of hypopigmented skin revealed trisomy 20 mosaicism. DISCUSSION: The occurrence of pigmentary mosaicism related to trisomy 20 mosaicism is exceptional. The combination of Ito hypomelanosis-type pigmentary mosaicism and delayed growth due to growth hormone deficiency has never been reported before. Our observation, unusual because of such an association, raises the question of the eventual existence of associated genes located on the chromosome 20 implied in the secretion of growth hormone and/or melanogenesis. It also underlines the interest of conducting cytogenic explorations on fibroblasts of damaged skin in the case of Ito-type pigmentary mosaicism, even if the blood karyotype is normal or in the absence of a patent phenotype abnormality.

Abnormalities, Multiple↗
PubMed2005

[Capillary malformations associated with cerebral cavernous malformation].

INTRODUCTION: Capillary malformations such as benign hereditary telangiectasia are a familial affection, of dominant autosomal transmission, characterized by the progressive development of cutaneous telangiectasia during childhood. The association with cutaneous vascular, arteriovenous or lymphatic malformations is exceptional and has only recently been described. CASE REPORT: A 5 year-old girl presented with widespread erythematous, predominantly telangiectasic, congenital and acquired macules when she was one year-old. Her history was marked by right temporal cerebral hemorrhage at the age of 4, revealing a right temporal cavernoma-like vascular malformation. The familial history of telangiectasic macules and clinical and histological examination led to the diagnosis of benign hereditary telangiectasia. DISCUSSION: This case report raises doubt on the exclusively cutaneous nature of benign hereditary telangiectasic-type capillary malformations. Moreover, it illustrates the possibility of a particular clinical form of this affection, associating classical telangiectasia and post-wine stain-type macules. The recent localization of the locus implied in this affection in 5q14 in the same chromosomic space as the CMC1 locus incriminated in familial capillary malformations, suggests that these two affections are in fact phenotype variations of a single and same clinical entity.

Central Nervous System Vascular Malformations↗
PubMed2005

[Erosive pustulosis of the scalp: 3 cases].

BACKGROUND: Erosive pustulosis of the scalp is a rare entity of unknown etiology mainly affecting elderly people. It is often triggered by local trauma and features chronic pustules of the scalp evolving toward scarring alopecia. Its treatment is not yet codified. OBSERVATIONS: Two patients (66 and 87 years old) presented with crusted and erosive pustules of the scalp following surgical removal of actinic keratosis and total skin graft. In a third patient, similar lesions appeared after hair grafting. Clinical features were consistent with the clinical pattern of erosive pustulosis of the scalp. In all three patients, oral zinc gluconate in combination with topical steroids associated resulted in significant improvement. CONCLUSION: An association of topical steroids and oral zinc gluconate might be an interesting therapeutic option in this chronic, often disabling affection.

Administration, Topical↗