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Biomedical subjects

O Dereure

Publications and source records attributed to O Dereure.

At least 73 records · Page 4Linked to original sources
PubMed2001

HFE mutations and transferrin receptor polymorphism analysis in porphyria cutanea tarda: a prospective study of 36 cases from southern France.

BACKGROUND: Porphyria cutanea tarda (PCT) is associated in most cases with iron overload, which may participate in decreased activity of uroporphyrinogen decarboxylase in the liver. The aetiology of this iron overload remains unknown; however, it has been demonstrated that mutations of HFE, the genetic haemochromatosis gene, might be present in a significant proportion of Anglo-Saxon and Italian patients. Furthermore, transferrin receptor polymorphism may influence the affinity of this receptor to its ligand with a subsequent increase of cellular iron absorption and storage. OBJECTIVES: To evaluate the incidence and spectrum of HFE mutations and the relative frequency of the two main alleles of transferrin receptor in patients with PCT originating from southern France, and to evaluate the relationship of these genetic data with iron status, and with hepatitis B and C and human immunodeficiency virus (HIV) infections. METHODS: Thirty-six consecutive patients with either sporadic or familial PCT were prospectively included between 1997 and 2000. Search for the presence of the three main mutations of the HFE gene and identification of the transferrin receptor alleles were performed using polymerase chain reaction followed by enzymatic digestion. Iron parameters and viral status for hepatitis B and C viruses and HIV were determined. RESULTS: Seven patients (19%) showed heterozygous C282Y mutation, but no C282Y homozygote was present; five patients (14%) carried homozygous H63D mutation, while eight (22%) were heterozygous for this mutation. One patient was heterozygous for the S65C mutation (3%). Iron parameters demonstrated overload in all patients, without a clear difference between patients with and without deleterious mutations of the HFE gene. Infection by hepatitis C virus was documented in 20 patients (56%), and was significantly less frequent in patients with deleterious HFE mutations. The profile of transferrin receptor alleles in PCT patients did not show significant variation compared with the general population. CONCLUSIONS: This study confirms the high frequency of HFE mutations in patients with PCT and supports the hypothesis that HFE gene abnormalities might play a significant part in the PCT pathomechanism, probably through iron overload; by contrast, transferrin receptor polymorphisms do not appear to play a significant part in iron overload in PCT.

Adult↗
PubMed2001

Drug-induced skin pigmentation. Epidemiology, diagnosis and treatment.

Drug-induced pigmentation represents 10 to 20% of all cases of acquired hyperpigmentation and this hypothesis must be systematically raised in unexplained pigmented lesions especially in elderly people. The pathogenesis of drug-induced pigmentation is variable according to the causative medication and can involve an accumulation of melanin, sometimes following a nonspecific cutaneous inflammation and often worsened by sun exposure, an accumulation of the triggering drug itself, a synthesis of special pigments under the direct influence of the drug or deposits of iron following damage to the dermal vessels. The influence of sun exposure is usually obvious in most cases, either by sun-induced melanin synthesis stimulation with formation of complexes between melanin and the causative drug or by transformation of the drug in visible particles usually taken up by dermal macrophages under the influence of sunlight. The main drugs implicated in causing skin pigmentation are nonsteroidal anti-inflammatory drugs, antimalarials, amiodarone, cytotoxic drugs, tetracyclines, heavy metals and psychotropic drugs. Clinical features are very variable according to the triggering molecule, with a large range of patterns and shades which are sometimes more or less reminiscent of the culprit drug. Histological findings are very variable as well but the colored particles are often concentrated within dermal macrophages which are sometimes localized in a distinctive fashion with respect to dermal structures such as vessels or adnexes. Treatment is often limited to sun-avoidance or interruption of treatment with the offending drug but laser therapy recently gave rise to hope of a cure in some cases. These measures are often followed by a fading of the lesions but the pigmentation may last for a long time or may even become permanent in a small percentage of patients.

Adult↗
PubMed2001

[Metastatic melanoma of unknown primary site].

INTRODUCTION: Melanomas of unknown primary site are rare. To establish their diagnosis the metastatic nature of the lesion must be confirmed clinically and histologically, the melanoid nature by histology and immunohistochemistry. Any primary melanoma must be eliminated by careful examination of the skin and mucosa, and the absence of past surgical excision of skin lesions must be confirmed. We studied the epidemiological, clinic and prognostic characteristics of 19 melanomas of unknown primary site in a series of 646 melanomas. MATERIAL AND METHODS: This retrospective study was conducted on a series of 646 melanomas recruited over a period of 14 years. The epidemiological (age, gender, phototype and family history of melanoma), clinical and prognostic parameters (relapse and global survival rate) were analyzed in 19 patients. Clinical and epidemiological data were compared with the 646 melanomas of the series. The prognostic parameters were compared with the melanomas of the series at the same stage. RESULTS: The melanomas with unknown primary site represented 2.94 p. 100 of our series and concerned 10 men and 9 women with a median age of 60 years. Eight patients presented stage III melanomas, according to MD Anderson's classification and 11 stage IV. Relapse after surgery was observed in 63 p. 100 of patients and 9 deceased during the observation period. In stage III patients the probability of survival after 2 years was of 51 p. 100 and for stage IV 34 p. 100. DISCUSSION: In our series the frequency of melanomas of unknown primary site is comparable to that observed in other studies. Compared to melanomas of known primary site, there was a preponderance in men and in slightly older patients. There was a majority of single glandular localizations and no particular site was preponderant. Survival of Stage III patients was comparable to that of melanomas of know primary site. However, for stage IV patients it appeared better, as has been noted in other series. Treatment of metastatic melanomas of unknown primary site should therefore be the same as that of classical forms. Whenever possible, surgery remains the first indication. Search for the primary site must be orientated by clinical examination including complete examination of the skin and mucosa (ENT, ophthalmologic and genito-urinary), eventually associated with paraclinical investigations, depending on the symptoms.

Adolescent↗
PubMed2000

T-Cell clonality in pityriasis lichenoides et varioliformis acuta: a heteroduplex analysis of 20 cases.

BACKGROUND: Cutaneous lesions of pityriasis lichenoides et varioliformis acuta (PLEVA), a T cell-mediated cutaneous inflammatory condition, are clinically similar to lymphomatoid papulosis (LyP), leading some authors to hypothesize that they are part of the same spectrum of lymphoproliferative disorders, although reports of the development of cutaneous lymphoma in patients with PLEVA are not as frequent as they are for patients with LyP. Furthermore, unlike in cases of LyP, no systematic search for a dominant T-cell clone has been carried out in cases of PLEVA, whereas clones have been detected in a few cases of PLEVA using mainly Southern blot analysis. OBJECTIVE: To investigate T-cell clonality in a series of archival PLEVA lesions. TISSUES: Archival paraffin-embedded biopsy specimens from 20 clinically and pathologically typical cases of PLEVA were selected. MAIN OUTCOME MEASURE: Identification of a dominant T-cell clone by polymerase chain reaction and heteroduplex analysis targeted on the TCRgamma gene. Peripheral blood mononuclear cells (PBMCs) and Jurkat cells were used as negative and positive controls. Serial dilutions of Jurkat T-cell lymphoma DNA in PBMC DNA were used to assess the sensitivity of the method. RESULTS: Analysis of 13 (65%) of 20 PLEVA biopsy specimens revealed the presence of a dominant T-cell clone. Positive and negative controls confirmed the specificity of the procedure. The sensitivity was determined to be between 1% and 5% of the total T-cell infiltrate. CONCLUSIONS: This study provides further evidence for the presence of a dominant T-cell clone in skin lesions of some patients with PLEVA and supports the hypothesis that PLEVA is part of the spectrum of clonal-T-cell cutaneous lymphoproliferative disorders.

Adolescent↗
PubMed2000

Multiple acral fibromas in a patient with familial retinoblastoma: a cutaneous marker of tumour-suppressor gene germline mutation?

We report a 40-year-old patient with familial retinoblastoma also affecting his elder son, who developed multiple fibromas on the periungual or subungual areas of all the fingers. Molecular analysis disclosed a loss of heterozygosity for the RB1 gene in the larger tumour, with disappearance of the normal allele and persistence of the mutated allele only. The similarity of this observation with distal fibrous tumours encountered in other diseases with germline mutations of tumour-suppressor genes such as neurofibromatosis type 1, tuberous sclerosis and multiple endocrine neoplasia type 1 led to the hypothesis that multiple acral benign tumours with a fibrous component might be a cutaneous marker of tumour suppressor gene germline mutation with low sensitivity but high specificity.

Adult↗
PubMed2000

Decreased expression of Fas (APO-1/CD95) on peripheral blood CD4+ T lymphocytes in cutaneous T-cell lymphomas.

BACKGROUND: The usually protracted and indolent course of cutaneous T-cell lymphoma (CTCL) is consistent with an accumulation of lymphocytes rather than being a true proliferative disorder, perhaps as the result of defective lymphocyte apoptosis. Fas (CD95) is the main signalling membrane molecule involved in postactivation T-lymphocyte apoptosis. OBJECTIVES: To evaluate expression of Fas on circulating CD4+ lymphocytes in patients with CTCL. METHODS: Fas expression on peripheral blood CD4+ T cells in 16 patients with mycosis fungoides (patch and infiltrated plaque stages) and in four patients with Sézary syndrome was compared with that in 25 matched patients with lymphocyte-mediated cutaneous benign inflammatory disorders and in 15 subjects without inflammatory cutaneous diseases. RESULTS: Fas expression on peripheral CD4+ lymphocytes was significantly lower in patients with CTCL compared with subjects with benign inflammatory cutaneous disorders and with healthy donors. CONCLUSIONS: This pattern supports the hypothesis that a defect in T-cell apoptosis may play a part in the pathophysiology of CTCL, perhaps through abnormalities of the Fas/Fas ligand system. Alternatively, this decrease could be the result of the presence of the soluble Fas ligand molecule in the sera of patients with CTCL.

Apoptosis↗
PubMed2000

Treatment of Old World cutaneous leishmaniasis by pentamidine isethionate. An open study of 11 patients.

BACKGROUND: Pentavalent antimonial derivatives (PAD), especially meglumine antimoniate (Glucantime((R))), are usually considered as the first-line drugs for Old World leishmaniasis, but their potential toxicity and the number of required injection, either intralesional or intramuscular, prompt to search for alternative treatments. OBJECTIVE: To evaluate the efficiency and tolerance of pentamidine isethionate in Old World leishmaniasis. METHODS: An open pilot study included 11 patients from two regional academic centers, with varied parasitological forms of Old World leishmaniasis, treated with three strictly intramuscular injections of 4 mg/kg of base-pentamidine every other day. RESULTS: Tolerance was good overall, and 8/11 (73%) of patients responded well with a quick healing of their lesions, little scarring and no relapse. CONCLUSION: Pentamidine isethionate is a safe and effective first-line treatment for Old World leishmaniasis. Larger-scale prospective studies comparing several dosage regimens of pentamidine and pentamidine isethionate to PAD are warranted.

Adolescent↗