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Biomedical subjects

O Dereure

Publications and source records attributed to O Dereure.

At least 109 records · Page 6Linked to original sources
PubMed1994

TP53 tumor suppressor gene and skin carcinogenesis.

The tumor suppressor gene TP53 encodes for a nuclear phosphoprotein involved in the control of cell proliferation, particularly in stressed cells. TP53 gene mutations are the most frequent genetic event found in human cancers. Most mutations locate in the highly conserved domains of the gene. Their localizations vary according to the tissue and tumor type, but define some hot spot regions that may have a certain degree of tissue specificity. In certain cases, the type of nucleotide substitutions observed can help to find the carcinogenic agent. In recent years, TP53 gene mutations have been frequently observed in human skin tumors. In epithelial carcinomas, they involve mainly exons 5, 7, and 8. Interestingly, many are C to T transitions at dipyrimidine sites; particularly, one can find CC to TT double-base changes that are known to be specific to ultraviolet radiation. These data confirm at the molecular level the role of ultraviolet radiation as an important etiologic factor in the genesis of these lesions. The high incidence of TP53 mutations suggest that they play a role in keratinocyte transformation. Nevertheless, this event has not yet been defined as an early or late event. In melanomas, most studies have shown the detection of the p53 protein by immunohistochemistry, suggestive of the presence of a mutation in the gene prolonging the protein half-life. Anti-p53 reactivity is frequent in these tumors and seems to correlate with tumor aggressiveness. Confirmation and characterization of TP53 gene mutation at the DNA level would help to precisely define the role of this gene in the development of these tumors.

Genes, Tumor Suppressor↗
PubMed1994

Biclonal Sézary syndrome with capillary leak syndrome.

Sézary syndrome is a rare, usually monoclonal proliferation of T lymphoid cells. We report a case of this form of cutaneous T cell lymphoma with highly probable biclonality of neoplastic proliferation. Biclonality in malignant lymphoma is a rare feature, until now generally reported in B cell lymphoma. Its identification by accurate immunological studies could be of importance since one of the two populations can exhibit a less differentiated phenotype requiring a more aggressive therapeutic regimen than usual. The occurrence of anasarca in our patient was probably due to capillary leak syndrome, already discussed in another case of peripheral T cell lymphoma.

Aged↗
PubMed1994

Inflammatory linear verrucous epidermal naevus with auto-immune thyroiditis: coexistence of two auto-immune epithelial inflammations?

We report a patient with an inflammatory linear verrucous epidermal naevus (ILVEN) coexisting with an auto-immune lymphocytic thyroiditis. The occurrence of two epithelial inflammatory processes could be linked and raises the question of auto-immune involvement in the inflammatory part of ILVEN. Moreover, expression of a membrane antigen, OKM5, usually assigned to antigen-presenting cells, especially macrophages, has been demonstrated on keratinocytes in some dermatological diseases including ILVEN. These data suggest that keratinocytes in ILVEN could present some antigens and perhaps auto-antigens modified by the hamartomatous process, leading to an (auto-immune?) inflammatory reaction.

Adult↗
PubMed1993

C3d,g deposits in inflammatory skin diseases: use of psoriatic skin as a model of cutaneous inflammation.

Recent studies in our laboratories have shown that human keratinocytes synthesize and secrete complement components including C3. Moreover, human keratinocyte-derived C3 is regarded as a potential source of C3d,g, a recently described constituent of the sublamina densa region of normal epidermal basement membrane. Additionally, human keratinocyte-derived C3 may also contribute to epidermal basement membrane deposits of C3 in autoimmune or inflammatory skin disorders. To further our understanding of the specificity and origin of epidermal basement membrane C3 deposits in normal and diseased skin, we have characterized in situ deposits of C3 and C3 cleavage fragments in various inflammatory skin diseases and utilized a skin equivalent model to assess the deposition of C3 cleavage fragments in neo-basement membrane of epidermal outgrowths from normal or diseased human skin. C3d,g reactivity was found to be greater in all samples of inflamed skin, and typically associated with C3c reactivity at these sites. No immunoglobulins or other complement components were detected. When lesional psoriatic skin rich in epidermal basement membrane C3c was used in our organ culture system, C3 incorporation within neo-basement membrane was observed. These results show that human keratinocyte-derived C3 may contribute to inflammatory reactions in skin as well as account for deposits of C3d,g in normal epidermal basement membrane.

Basement Membrane↗
PubMed1993

TP53 tumor-suppressor gene and human carcinogenesis.

The wild-type tumor-suppressor TP53 gene encodes for a nuclear protein which has been shown to act as a transcriptional modulator. The cellular role of the p53 protein is the control of cell proliferation, particularly important in stressed cells. The TP53 gene is frequently mutated in sporadic and familial human cancers. Most transforming mutations localize in highly conserved domains of the gene and define hot-spot regions that have a certain degree of tissue specificity. Moreover, most mutations are point mutations and the type and localization of the nucleotide substitution may sometimes help in recognizing the carcinogenic agent. This is the case for C to T transitions at dipyrimidine sites induced by UV radiation in cutaneous epitheliomas. Inactivation of p53 protein can also occur through mechanisms other than genetic alteration, such as binding to viral or cellular proteins. Loss of wild-type TP53 function seems therefore to play a crucial role in cell transformation in human cancers, either during carcinogenesis or later in tumor progression.

Cell Division↗
PubMed1993

[Phakomatosis pigmento-vascularis. Report of 2 cases associated with angiodysplasia].

Phakomatosis pigmentovascularis is an uncommon disease, with a peculiar association of capillary hemangioma and pigmented lesions. Four entities have to date been described (I to IV), with localized (a) or systematical (b) involvement. In this latter subtype, the cutaneous lesions are associated with visceral (eye, central nervous system) and bony abnormalities. We describe two additional cases of phakomatosis pigmentovascularis type II (b) associated with a Klippel-Trenaunay syndrome. These reports emphasize the frequent occurrence of angiodysplasia of the Klippel-Trenaunay or Sturge-Weber-Krabbe type in the systemic subtype, especially II (b). Accordingly, complete investigations are warranted in all cases, with special attention for bones and some internal organs like eye and central nervous system. Pathophysiological hypothesis for phakomatosis pigmentovascularis are discussed.

Adult↗
PubMed1993

[Carcinomatous degeneration of chronic osteomyelitic fistulae. 4 cases].

The occurrence of epidermoid carcinoma on fistulae of osteomyelitis has been known since the 19th century, and the four cases reported here show that this complication is still present. CASE-REPORTS. Four new cases developed on the tibia 33 to 54 years after the formation of fistulous osteomyelitis are presented here. The patients were three men and one woman, aged from 58 to 78 years. The lesions observed were ulcero-granuloma in three cases and common superficial ulceration in the fourth patient. In two out of four cases the diagnosis was difficult to ascertain and required deep surgical biopsy. The bone was invaded in three cases, but no regional or visceral metastases could be found. All patients were amputated, after failure of conservative radiotherapy in two of them. No recurrence was observed after a 2 to 3 1/2 years' follow-up. DISCUSSION. The frequency of this late complication cannot be measured precisely, but it has been estimated at 0.5 p. 100 of fistulous osteomyelitis. The warning signs are often not specific and delay the diagnosis; they consist of unusual pain, ulceration, granulation and discharge. The diagnosis rests on histology and requires a deep and wide surgical biopsy involving the entire sinus tract, but uncertainties sometimes persist concerning atypical pseudoepitheliomatous hyperplasia. The best treatment is amputation with removal and biopsy of regional lymph nodes when present, but it does not always avoid the occurrence of metastases which appear in 20 p. 100 of the cases, usually during the first three years following diagnosis. CONCLUSION. These four cases exemplify the need to consider this diagnosis in all patients showing changes in an old fistulous osteomyelitis and to confirm it by deep and wide biopsy.

Aged↗
PubMed1993

[Mycosis fungoides following non-Hodgkin's cutaneous B-cell lymphoma].

INTRODUCTION: B-cell and T-cell lymphomas are seldom found associated. We report a new case with purely cutaneous lesions. CASE-REPORT. In 1990, a 59-year old man was treated for cutaneous B-cell lymphoma with few lesions. One year later the patient developed a tumoral mycosis fungoides which soon recurred after whole body electron-therapy. DISCUSSION: The association of two lymphoid blood diseases of different phenotypes is probably not coincidental. It might be related to a particular evolutive profile of T-cell lymphoma, and this leads us to discuss some hypotheses concerning the physiopathology of lymphomas, and notably the cutaneous lymphomas.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

[Carcinoma of the tongue in xeroderma pigmentosum].

Xeroderma pigmentosum (XP) is a rare genodermatosis characterized by a defect in the repair of DNA damage induced by ultraviolet rays. The cutaneous tumours are frequent and occur at an early age, but neoplasias of the mucosae are seldom observed. Among the mucosae, the lipids and the conjunctiva clearly predominate. Tumours of the buccal cavity are much less frequent, and this is why we report a case of epidermoid carcinoma of the tip of the tongue in a Moroccan boy. Only 25 cases of intrabuccal tumour have been reported in patients with XP, and 22 were epidermoid carcinomas of the tip of the tongue. These carcinomas may be preceded by precancerous lesions such as leucoplasia. The early occurrence and elective location at the tip of the tongue clearly differentiate lingual carcinomas associated with XP from their homologues in adults. The aggressiveness of these lesions is difficult to determine due to a usually short follow-up and to the lack of details in reports. Treatment is surgical and non-specific. Concerning epidemiology, the predominance of African and Near-Eastern patients among those suffering from lingual carcinoma is striking. Moreover, when the complementation group is known it is always group C; our patients presented with characteristics of this group. Some authors believe that the lingual tumours are due to ultraviolet light (overexposure in case of natural pigmentation, with exposure of the tip of the tongue) and to certain toxic substances in food.(ABSTRACT TRUNCATED AT 250 WORDS)

Basal Cell Carcinoma↗
PubMed1992

[Role of oncogenes and anti-oncogenes in dermatology].

Cell growth is controlled by two types of genes, i.e., activating genes (oncogenes) and negative regulator genes (antioncogenes). Studies have shown that malignant transformation of a cell can result from either increased oncogene activity or decreased antioncogene activity. Current knowledge of genes relevant to dermatology is discussed.

Animals↗
PubMed1990

[Cutaneous lesions in POEMS syndrome. Apropos of 3 case reports and a review of the literature].

We present three new cases of POEMS syndrome with the most common cutaneous signs of this entity. The syndrome is a multivisceral complex, mostly described in Japanese patients, which includes polyneuropathy, organomegaly, endocrine disorders, monoclonal gammopathy and skin changes. The latter are constant but sometimes reduced to one type of lesion. The most frequent are hyperpigmentation sparing the mucosae, hypertrichosis, scleroderma-like skin thickening and capillary angiomas. The other signs are much less common, as shown in table I. Histological findings are seldom reported and usually have little specificity. None of these abnormalities is pathognomonic, but their predominance at the extremities may be suggestive and leads to a search for other elements of the syndrome, notably gammopathy. The main differential diagnostic problem is with scleroderma, sometimes circumscribed and often systemic. Some cases are very ambiguous. The relationship between the two diseases would suggest the existence of one or several common pathogenic factors. The overall physiopathology of POEMS syndrome is obscure. The role of endocrine disorders in the genesis of the cutaneous signs is subject to discussion: hyperoestrogenism may explain some of these signs, but hypertrichosis is incompatible with the frequent finding of low androgen secretion. The role of one or several "toxic" substances secreted by plasmocytes is highly hypothetical. In some cases, the skin abnormalities have regressed after treatment of gammopathy, and in rare patients the recurrence of gammopathy was followed by that of skin lesions. In a few cases, a "paraneoplastic" character may be suspected.

Adult↗
PubMed1988

[Acute febrile neutrophilic dermatosis and malignant hematologic diseases: report of a new bullous case and review of the literature].

A new case of Sweet's syndrome (acute febrile neutrophilic dermatosis) associated with a malignant hemopathy is presented. The blood disease was a chronic myelomonocytic dysmyelopoiesis which was discovered during the eruption and resulted in the patient's death within a few months, probably through acutization. The skin lesions were atypical, bullous and ulcerated. On this occasion, the international literature concerning all cases of Sweet's syndrome associated with malignant or premalignant hemopathies is reviewed. Several concepts emerge from this study: the association is frequent (about 20 p. 100 of all published cases of Sweet's syndrome); there is a strong predominance of granulocytic hemopathies over lymphoplasmocytic and monocytic hemopathies; the blood disease is revealed by the skin eruption in some 50 p. 100 of the patients; there are frequent chronological relations between Sweet's syndrome and the events that occur in the course of the hemopathy; finally, the association is usually of poor prognosis. A comparison with Sweet's syndrome unassociated with a blood disease showed only three significant points: the frequency of bullous lesions, of the initial anaemia (the most important element) and of extreme figures in leucocyte counts (leucopenia or major hyperleukocytosis). The atypical character of the skin lesions in the patient presented here incites to discuss the nosological relationship between Sweet's syndrome and bullous pyoderma, an entity closely associated with hemopathies. It has recently been suggested by several authors that this anatomico-clinical kinship should be turned into a wide spectrum of acute neutrophilic dermatoses, with typical Sweet's syndrome at one end and Pyoderma gangrenosum at the other end. The interface between this spectrum and haemopathies seems to be maximum at its intermediate stage: the bullous and superficially ulcerated lesions. The aetiology and pathogenesis of this new nosological entity are uncertain. The presence of chemoattractants or of polymorphonuclear cell abnormalities is still open to discussion. The relationship between the entity and leukocytoclastic vasculitis has recently been questioned.

Aged↗