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Biomedical subjects

L Machet

Publications and source records attributed to L Machet.

At least 91 records · Page 5Linked to original sources
PubMed1994

Ultrasound imaging of psoriatic skin: a noninvasive technique to evaluate treatment of psoriasis.

BACKGROUND: The aim of our study was to image psoriasis plaques by ultrasound to assess the changes in psoriasis and to measure and quantify them objectively. MATERIALS AND METHODS: Thirty-one psoriasis plaques were studied in 19 patients. Measurements of skin thickness were obtained with a high resolution B-mode echographic system. RESULTS: Some changes were seen in psoriatic skin. A new structural element was observed: a wide subepidermal nonechogenic band. The other changes were a decrease in dermal echoes that were less intense and less dense, and an increase in the epidermal and dermal skin thicknesses. The skin thickness was increased in all psoriasis plaques as compared to apparently normal skin (P < 0.001). The average increase was 67% for whole skin and 200% for epidermis. CONCLUSIONS: Ultrasound imaging of psoriatic skin allowed the identification of different skin changes induced by psoriasis, and particularly, the differentiation between epidermal and dermal alterations. We presume that epidermal thickness reflects epidermal proliferation and desquamation, and the increase in the dermal and whole skin thickness reflects infiltration. We feel that ultrasound imaging of psoriatic skin is a quantitative method that is as easy and noninvasive as the psoriasis area and severity index (PASI). It could be used for following up patients with psoriasis and could achieve widespread use, especially in research protocols.

Adult↗
PubMed1993

Effects of short-time hydration on skin extensibility.

Vertical cutaneous extensibility was studied before and after 1, 2, 5 and 10 min hydration by application of tap water. After hydration, we noted an increase in all rheological parameters linked to elasticity whereas viscosity and hysteresis parameters were unmodified. These modifications took place from the first minute and increased thereafter. Men and women showed identical values prior to hydration. After hydration, an extensibility gain was noted only in the women, men's extensibility being unmodified. Studying rheological behaviour as a function of age, we showed similar modifications in younger and older groups, the extensibility gain being greater in the older group. Prior to hydration, the stratum corneum was extremely rigid and extensibility was comparable between men and women. Hydration, softening the horny layer, allows a rapid extensibility gain proportional to the reduced thickness of the dermis, especially in women and older subjects.

Adult↗
PubMed1993

Localized atypical pemphigoid on lymphoedema following radiotherapy.

Autoimmune bullous diseases have been reported associated with different causal factors: drugs, mechanical trauma and physical trauma, particularly ultraviolet light and radiotherapy. In these cases different hypotheses regarding the pathogenesis of blister formation can be supported. In this observation, we report a localized cicatricial pemphigoid with unusual clinical presentation. Moreover, it appeared 9 years after radiotherapy for breast carcinoma and it was preferentially localized on an upper limb lymphoedema. Because of the long time between the treatment of carcinoma with radiotherapy and the onset of pemphigoid, we assume that lymphoedema played a major etiological role in this particular cicatricial pemphigoid.

Aged↗
PubMed1993

[Actinomyces meyeri cutaneous actinomycosis with pulmonary localization].

Infections due to Actinomycosis species are located in the cervico-facial region in 50 to 65 percent of the cases. Extra-cervical cutaneous lesions are exceptional. The most frequently encountered germ is Actinomyces israeli, observed in 85 percent of the cases. We report the case of an Actinomyces meyeri infection which presented as a leg abscess and a pulmonary lesion. There was no cervico-facial localization. There was however a chronic parodontitis. A second germ, Capnocytophaga sp. was isolated from the abscess. This case is of particular interest because of the extracervical localization and the rare species isolated (17 other cases of Actinomyces meyeri infection have been reported). The mechanism of the infection can be better understood in light of pulmonary lesions in the lower right lobe due to inhalation and the coexistence of a buccodental germ in the culture of the leg abscess: buccodental origin of the germ, pulmonary lesion secondary to inhalation, septicaemic dissemination with cutaneous metastases.

Actinomycosis↗
PubMed1993

[Disseminated xanthosiderohistiocytosis with cardiac involvement and monoclonal gammapathy].

Xanthosiderohistiocytosis is a rare non-Langerhans histiocytosis (4 reported cases). The clinical characteristics include diffuse, sometimes deep, dark-brown infiltrations of the skin. Histological examination reveals abundant deposits of haemosiderin within the histiocyte proliferation. This entity is a clinical form of Montgomery's disease (xanthoma disseminatum) which has been reported in over 100 cases. Our case of disseminated xanthosiderohistiocytosis was particular because it involved the heart and was associated with a monoclonal gammapathy. Five cases have been reported associating xanthoma disseminatum and monoclonal gammapathy, including one case of xanthosiderohistiocytosis. In our case, rapidly increasing levels of monoclonal immunoglobulin suggested an evolution towards a myeloma. A monoclonal gammapathy should be looked for and monitored in cases of xanthosiderohistiocytosis, and more generally xanthoma disseminatum because of the risk of developing lymphoma or myeloma.

Aortic Valve Stenosis↗
PubMed1992

Levels of fusidic acid in skin blister fluid and serum after repeated administration of two dosages (250 and 500 mg).

The fusidic acid steady-state concentrations in serum (S) and skin suction blister fluid (SBF) after oral doses of 250 and 500 mg administered twice daily for 6 days, as film-coated tablets of sodium fusidate, were studied in eight healthy subjects. The mean peak serum concentrations after the 250- and 500- mg regimens were 39 +/- 5 and 102 +/- 11 mg/l, respectively, obtained between 2 and 3 h after drug intake. The corresponding values for SBF, obtained later, between 2 and 12 h after drug intake, were 21 +/- 5 and 79 +/- 11 mg/l. As measured by the ratio of area under the concentration vs. time curve (SBF/S), fusidic acid penetration is 69-75%, whatever the dose. With either regime, the fusidic acid SBF and serum levels exceed the minimal inhibitory concentration of bacteria usually found in skin infections, especially Staphylococcus species. A dose of 250 mg twice a day appears sufficient to treat these infections and could be tested in clinical studies.

Adult↗
PubMed1992

Contact and photocontact allergy to oxybenzone.

The purpose of this study was to determine the frequency of contact allergy and photocontact allergy to sunscreens. A consecutive series of 54 patients with suspected clinical photosensitivity were assessed. All had the same standardized photobiological investigation from January 1989 to December 1990, including patch tests and photopatch tests with 6 sunscreen agents. Oxybenzone was found to cause 4 cases of allergic contact dermatitis (with photoaggravation in 2), and 3 cases of photocontact dermatitis (13% of patients). This is probably due to the wide distribution of oxybenzone in sunscreens and other cosmetics, 2 patients with polymorphic light eruption and persistent light reactivity, respectively, were regular sunscreen users. Photobiological investigation is necessary to ensure accurate diagnosis, since sunscreen contact or photocontact allergy may simulate other photosensitivity eruptions.

Adult↗
PubMed1992

Carpal tunnel syndrome and systemic sclerosis.

Carpal tunnel syndrome (CTS) was observed in 4 cases of a consecutive series of 16 patients admitted for the initial diagnosis or follow-up of systemic scleroderma from 1986 to 1990. We also observed one case of ulnar nerve compression. Neurological involvement was confirmed by electromyogram, and motor and sensory nerve conduction studies. The neurological signs appeared at the beginning of the disease in two cases and preceded the discovery of scleroderma in two. CTS is not rare in scleroderma and must be carefully sought, both clinically and electrophysiologically. Patients with 'idiopathic' CTS might need clinical follow-up for early diagnosis of scleroderma.

Adult↗
PubMed1992

Schnitzler's syndrome (urticaria and macroglobulinemia) associated with pseudoxanthoma elasticum.

Schnitzler's syndrome, first described in 1974, is defined by chronic non-pruritic urticaria, osteocondentation, and a monoclonal IgM dysproteinemia, but without criteria of lymphoproliferative disease. We report a patient with chronic urticaria and macroglobulinemia. In addition, he had double monoconal dysproteinemia IgM kappa (31.3 g/l) and IgA lambda, osteocondensation, and some cutaneous lesions of pseudoxanthoma elasticum. Only 20 cases of Schnitzler's syndrome have been reported hitherto. This is the first case associated with pseudoxanthoma elasticum, which was localized and discovered at the same time as Schnitzler's syndrome. We discuss the possible role of monoclonal immunoglobulin in the occurrence of localized elastorrexhis.

Aged↗