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Biomedical subjects

Y Privat

Publications and source records attributed to Y Privat.

At least 19 recordsLinked to original sources
PubMed1992

Influence of age and sun exposure on the biophysical properties of the human skin: an in vivo study.

The physical properties of the skin were measured by using noninvasive methods on 72 people displaying various levels of solar elastosis on the neck. The physical parameters measured were the skin extensibility, the elastic recovery, the skin colour, the skin thickness and the electrical conductance. The correlation between the above parameters, the clinical grades of elastosis and the chronological age of each subject were studied using two different statistical approaches. They both showed that elastotic skin is less elastic, dryer, darker, more erythematous and less yellowish than the nonexposed skin. The similarities and differences between the properties of elastotic skin and purely chronologically aged skin are discussed.

Adult↗
PubMed1992

[Klinefelter's syndrome and leg ulcers: role of blood coagulation disorders].

Genetically, Klinefelter's syndrome is characterized by a super-numerary chromosome X in male subjects presenting with clinical and biochemical hypoandrogenism and relative hyperoestrogenism. The association of Klinefelter's syndrome with chronic leg ulcer has given rise to numerous publications. The cause of the trophic disorders is unclear. We report two cases of this syndrome associated with chronic leg ulcers and anomalies of haemostasis. One of these two patients had platelet hyperaggregability followed by disorders of fibrinolysis, while the other had disorders of fibrinolysis. We reviewed the literature concerning the various aetiopathogenic hypotheses put forward to explain the cause of these leg ulcers, as well as their interactions and relationship with the hormonal anomalies. The position occupied by disorders of haemostasis is particularly developed.

Adult↗
PubMed1990

[Essential fatty acids and the skin].

Metabolism of the essential fatty acids (AGE) in an organism leads to synthesis of eicosanoids, which have various biological properties. Linoleic acid plays an important part in maintenance of epidermal integrity by intervening in the cohesion of the stratum corneum and in prevention of transepidermal water loss. Metabolites of arachidonic acid (mostly those obtained by the lipoxygenase pathway) are important agents in causing many inflammatory skin reactions concurrent with development of skin diseases such as psoriasis and atopic dermatitis. Pharmacological and dietetic control of the metabolism of arachidonic acid is a new and interesting therapeutic concept in the care of skin diseases. Also, fish oil, which is rich in linoleic acid and poor in arachidonic acid, seems to be useful in basal treatment of psoriasis. The value of evening primrose oil, which is rich in gamma-linoleic acid, in the treatment of atopic dermatitis is discussed.

Acne Vulgaris↗
PubMed1989

Eosinophilic pustular folliculitis (Ofuji's disease): efficacy of isotretinoin.

The case of a 30-year-old man with a 6-year history of eosinophilic pustular folliculitis (EPF) is reported. Isotretinoin (1 mg/kg/day) led to a dramatic improvement of all the lesions within 2 weeks. The withdrawal of the drug was followed by a recurrence after 10 days of the papulopustular, follicular and pruritic lesions. Reintroduction of isotretinoin was successful. The benefits of isotretinoin in the treatment of EPF have, to the best of our knowledge, never been reported previously. The mechanisms underlying this efficacy may involve the inhibition of the eosinophilic chemotactic factors thought to be present in sebaceous lipids and in the stratum corneum of patients suffering from EPF.

Adult↗
PubMed1989

Benefit of progressively increasing doses during the initial treatment with acitretin in psoriasis.

The purpose of this double-blind study was to compare the therapeutic effects of a low initial dosage of acitretin, increased at 2-week intervals (group 1: 10, 30, 50 mg/day) with a high initial dosage decreased at similar intervals (group 3: 50, 30, 10 mg/day) and with a constant dosage (group 2: 30 mg/day) in 66 patients (47 men and 19 women) with severe psoriasis. At the end of the double-blind phase, the mean percent improvement, calculated by the Psoriasis Area and Severity Index score, was as follows: 62.7% in group 1, 55.9% in group 2 and 67.1% in group 3. The double-blind phase of 6 weeks was followed by an open phase of 6 weeks, during which the patients were treated either with 10, 30 or 50 mg/day, according to the therapeutic response. At the end of treatment (12 weeks), a mean improvement of more than 80% was obtained in all three groups. Hypervitaminosis A signs and symptoms were observed in all patients. The frequency and severity of these adverse reactions were shown to be dose-dependent. This study shows that a low dose progressively increased is advisable because of similar activity and better acceptability.

Acitretin↗
PubMed1989

Determination of acitretin and 13-cis-acitretin in skin.

The aim of the study was to investigate the concentrations of Ro 10-1670 (acitretin) and its isomeric metabolite Ro 13-7652 (cis-acitretin) after multiple oral dosing of acitretin. We used a highly sensitive HPLC method for simultaneous determination of the 2 retinoids with a quantification limit of 2 ng/ml in plasma and 10 ng/g in total skin (epidermis and dermis). In hairless rats receiving orally 8 mg/kg acitretin once daily during 8 days, blood and skin samples were taken at different time points between 5 and 96 h after the last dose. After 96 h, appreciable concentrations of Ro 10-1670, but not Ro 13-7652 could be measured in the skin, whereas both isomers were below the quantification limit in plasma. In psoriatic patients treated with a once daily dose of 30 mg acitretin, blood samples and biopsies were taken after 1 month of treatment (i.e. under steady state conditions). 24 h after the last drug intake, skin concentrations of acitretin were approximately 10 times higher than those observed in plasma. Ro 10-1670 concentrations in the skin were approximately 3-5 times higher than for Ro 13-7652 and concentrations of both isomers were higher in lesional compared to uninvolved skin.

Acitretin↗
PubMed1989

[Value of colchicine in treating acquired epidermolysis bullosa].

In July 1986, a 46-year old male patient was admitted for a bullous skin disease of 4 years' duration. The disease fulfilled all the criteria of epidermolysis bullosa acquisita (EBA), as laid down by Roenigk and Pearson. Despite a guided investigation, none of the diseases classically associated with EBA could be found, but it must be noted that immunological stigmata of an old hepatitis B were present. After failures or partial results with prednisone alone (1 mg/kg/day from August to October 1986), then methotrexate (30 mg/week) combined with prednisone (20 mg/day), the patient was treated with colchicine in doses of 2 mg per day, and within a fortnight a dramatic improvement of buccal mucosal lesions and cutaneous fragility was observed. Colchicine was withdrawn, but 5 days later bullae and erosions of the mucosa reappeared. The reintroduction of colchicine in the same doses (2 mg/day) resulted in remission of the lesions. The disease has now remained stable for one year under colchicine 1 mg/day. Four attempts at reducing this dosage to 1 mg every other day brought about the recurrence of a few bullae and of cutaneous fragility. To our knowledge, colchicine has not yet been reported to be effective in the treatment of EBA. Its effectiveness may be due, to a great extent, to its immunomodulating properties, notably on some functions of neutrophils the role of which in the pathogenesis of bullous lesions seems to have been established. By modulating collagen synthesis and collagenase activity colchicine might induce structural modifications of the EBA antigen, identified as the carboxyterminal group of type VII collagen, and inhibit its recognition by autoantibodies.

Colchicine↗