Biomedical subjects

Pascale Quatresooz

Publications and source records attributed to Pascale Quatresooz.

28 records · Page 2Linked to original sources

PubMed2004

Mosaic subclinical melanoderma: an Achilles heel for UV-related epidermal carcinogenesis?

Cutaneous cancers are not uncommon on the face of elderly patients. Melanin should protect, at least in part, against the ultraviolet (UV)-induced neoplastic damage. However, the density in melanin chromatophores is heterogeneous in the epidermis of Caucasian adults. The computerized UV light-enhanced visualization (ULEV) method is a sensitive tool to assess non-invasively this mosaic pattern of intra-epidermal melanin load. In this study, the combination of ULEV pattern analysis and image analysis were performed involving four groups of phototype III Caucasian subjects. The first group was composed of 55 patients aged from 65 to 75 years who suffered from several malignancies of facial skin. The second control group of 55 patients who never had developed skin cancers were matched with the first group for age, sex and phototype. The third group was composed of 80 patients aged from 49 to 59 years who had developed a single basal cell carcinoma. The fourth group comprised 80 age, sex and phototype-matched healthy control subjects. Irrespective of the groups of subjects, a correlation was found between the pattern grading and the objectively determined relative area of subclinical melanoderma. Patients with multiple skin cancers differed from the other groups by the fact that a significantly higher proportion of them exhibited an extensive type of subclinical melanoderma. This feature was also seen in a minority of patients with a single basal cell carcinoma. The extensive subclinical melanoderma pattern is interpreted as a clue for risk, but not as a cause of UV-induced skin carcinogenesis.

Aged↗

PubMed2003

Deletion (6)(p22p25) is a recurrent anomaly of thymoma: report of a second case and review of the literature.

A patient with type AB thymoma and del(6)(p22p25) as the sole cytogenetic anomaly is described. This is the second report of a del(6)(p22p25) in a thymoma. The same deletion was previously found in association with a type A thymoma. Both patients presented with benign tumors. These data suggest that partial deletion of the short arm of chromosome 6 is a nonrandom change associated with benign thymomas.

Chromosomes, Human, Pair 6↗

PubMed2003

Differential expression of alpha1 (IV) and alpha5 (IV) collagen chains in basal-cell carcinoma.

BACKGROUND: Basement membrane alterations are common in malignancies, and they may indicate tumoral aggressiveness. Distinct patterns of tumoral coverage by collagen IV were reported in nodular and aggressive basal-cell carcinomas (BCCs). Differential expressions of alpha (IV) collagen chains were also shown on frozen sections. The aim of our work was to document the immunohistochemical expression of alpha1, alpha3, and alpha5 (IV) collagen chains in BCC after routine fixation and processing. METHODS: The patterns of distribution of alpha1 (IV), alpha3 (IV), and alpha5 (IV) collagen chains were studied in 20 formalin-fixed and paraffin-embedded BCCs showing different infiltrative patterns. One trichoblastoma was used as control. RESULTS: In nodular BCCs, the expression of alpha5 (IV) collagen chain was downregulated and uneven. By contrast, alpha1 (IV) collagen chain expression was preserved around these tumors similar to the surrounding skin. However, the alpha1 (IV) collagen chain expression was discontinuous or absent in BCC areas showing an infiltrative pattern of extension. The alpha3 chain was absent both underneath all BCCs and non-neoplastic skin. CONCLUSIONS: The basement membrane alterations around nodular BCCs involved more precisely the alpha5 (IV) collagen chains. Defects in alpha1 (IV) collagen chain expression seemed to be associated with a tumoral invasive and infiltrative pattern. The biological significance of these findings is unclear.

Basal Cell Carcinoma↗

PubMed2003

Incidental control of rosacea by somatostatin.

BACKGROUND: The precise pathomechanism of rosacea remains elusive. The disease commonly requires long-term treatments using topical or oral therapies. OBJECTIVE: This report presents incidental findings about the possible modulatory role of somatostatin in the outcome of rosacea. METHOD: Four patients presenting long-standing recalcitrant facial rosacea were treated with octreotide for diabetic retinopathy. RESULTS: Rosacea improved rapidly and even cleared without any recurrence in 3 of the patients. CONCLUSION: The beneficial effect might be attributed to inhibitory actions on the sebaceous gland, the neovascularization and/or on the inflammatory process.

Diabetes Mellitus, Type 1↗

PubMed2003

Nudging epidermal field cancerogenesis by imiquimod.

BACKGROUND: The coexistence of malignancies close to each other on the skin has been occasionally reported. The concept of field cancerogenesis applies to such cases. Given the purported mechanism of action of imiquimod, it should not be surprising that this treatment could inhibit epidermal field cancerogenesis. AIM: To assess the effect of imiquimod applied twice weekly on incipient bowenoid changes disclosed in the vicinity of basal cell carcinomas. MATERIALS AND METHOD: Biopsies were taken before treatment and after 4-6 weeks and 12 weeks of imiquimod treatment. RESULTS: Large atypical bowenoid keratinocytes and dyskeratotic cells were cleared in time while factor-XIIIa-positive dermal dendrocytes appeared boosted and admixed with a brisk lymphocytic infiltration. CONCLUSION: Epidermal field cancerogenesis appears to be controlled by imiquimod. Dermal dendrocytes might play a pivotal role in this regression phenomenon.

Administration, Topical↗

PubMed2003

Histometric assessment of psoriatic plaques treated by vitamin D3 derivatives.

BACKGROUND: Psoriasis is an immunogenetic disorder. Factor XIIIa+ dermal dendrocytes (DD) are part of the pathobiological changes in the plaque type of the disease. OBJECTIVE: The present study aimed at comparing the effect of 3 vitamin D(3) derivatives on the epidermis, microvasculature and DD in psoriasis. METHOD: Twenty men suffering from chronic plaques of psoriasis on the trunk were enrolled in this study. They applied twice a day for 3 weeks calcipotriol, tacalcitol and calcitriol, each to one plaque. Another similar lesion received petrolatum as a placebo treatment. Skin biopsies were taken at entry and at completion of the 3-week treatment phase. Immunohistochemistry was performed using the lectin of Ulex europaeus and an antibody to factor XIIIa. Computerized image analysis served to measure the stratum Malpighii area, the microvasculature area and the DD numerical density in the papillary dermis. RESULTS: At entry in the study, the 4 test sites were indistinguishable with regard to the stratum Malpighii area, the papillary microvasculature area and the papillary DD density. The 3 histometric parameters appeared correlated with each other. At completion of the 3-week treatment phase, the 3 vitamin D derivatives had decreased the size of the stratum Malpighii. In addition, calcitriol had also reduced the DD density in the papillary dermis. No other significant changes were yielded. CONCLUSION: As assessed by histometry, the psoriatic epidermis responded to a short treatment using the 3 vitamin D derivatives. The better result compared to the control site was achieved by calcitriol. DD appeared to be most controlled by the same drug. The microvasculature did not appear to be decreased at the 3-week time point in treatment.

Adult↗

PubMed2003

Factor-XIIIa-positive dendrocytes in drug-induced toxic epidermal necrolysis (Lyell's syndrome): paradoxical activation in skin and rarefaction in lymph nodes.

BACKGROUND: Drug-induced toxic epidermal necrolysis (TEN) is a rare life-threatening disease characterized by the extensive destruction of the epidermis contrasting with the discreteness of lymphoid cell infiltration. The precise pathomechanism of the disease remains unclear. METHODS: Skin specimens and peripheral and thoracic lymph nodes (LNs) were collected from 2 TEN patients. They were examined by conventional histology and immunohistochemistry using antibodies directed to factor XIIIa (dermal dendrocytes), CD1a (Langerhans cells), CD15 (granulocytes), CD20 (B lymphocytes), CD45RO (activated T lymphocytes), CD68 (macrophages) and the proliferation marker Ki-67. LNs from patients with mycosis fungoides, from subjects dead from acute cardiac failure or traumatic injuries, as well as metastasis-free sentinel LNs of cutaneous melanoma served as positive and negative controls. RESULTS: TEN LNs showed absence of germinal centers but a moderate hyperplasia of the paracortical T cell zone. Immunohistochemistry did not reveal any distinctive aspect in LN cellular densities between TEN and other control conditions except for the factor-XIIIa+ dendritic cells which were dramatically reduced in numbers in TEN LNs. This rarefaction in LNs contrasted with the great number of these cells in the skin of the same patients. CONCLUSION: The structure of TEN LNs rules out the involvement of an antibody-mediated response. As dendritic factor-XIIIa+ cells are involved in most cutaneous T-cell-mediated responses, their depletion in TEN LNs could explain the sparse lymphoid cell infiltrate in lesional TEN skin.

Aged↗

PubMed2003

Deciphering the impaired cytokine cascades in chronic leg ulcers (review).

Chronic leg ulcers are typically wounds that do not heal at a normal rate. Impaired healing appears to be due to primary microvascular changes and it is aggravated by ongoing bacteria-driven vasculitis. The various cytokines identified in experimental wounds are also present in leg ulcers. VEGF is strongly implicated as a promoter of blood vessel growth in patients with venous disease. In addition, there is good evidence of increased expression of bFGF, TGF-beta1, and PDGF in lipodermatosclerosis. All of these growth factors are involved in wound healing. Upregulated TGF-beta1 is probably one of the main causes of the fibrosis observed in lipodermatosclerosis. In leg ulcers, cytokines appear to be trapped in the perivascular fibrinoid deposits. It is not the nature and amount of cytokines that are inadequate in leg ulcers, but rather their spatial distribution. Dermal dendrocytes (DD) are resident factor XIIIa-enriched macrophages. They likely play a role in tissue repair when boosted adequately. New therapies aiming at helping the release of cytokines by DD apparently promote and improve the healing phase.

Animals↗

PubMed2002

Stereotactic breast biopsy with an 8-gauge, directional, vacuum-assisted probe: initial experience.

This study was prospectively conducted to assess the feasibility, safety and accuracy of an 8-G directional vacuum-assisted biopsy (DVAB) probe in the diagnostic management of nonpalpable breast lesions (NPBL). Of 170 planned procedures which were indicated for investigation of BI-RADS category-3 to category-5 lesions, 153 were performed in 138 consecutive patients. The probe was targeted by the stereotactic unit of a prone table (United States Surgical Corporation, Norwalk, Conn.; and Lorad, Danbury, Conn.). Four to 18 (mean 8) core specimens were obtained for each lesion. In case of complete removal of the lesion, a localizing clip was deployed at the biopsy site. Adequate material for histopathologic examination was obtained in all cases (100%). Four of 138 (3%) patients experienced mild hematomas. We observed 15 of 39 failures (38%) to place the localizing clips. Thirteen of 153 (8%) procedures were inconclusive and required reintervention. Following DVAB, 42 of 138 (30%) patients underwent surgery. Subject to incomplete follow-up of the entire cohort, we observed no false-positive and one false-negative diagnosis. These preliminary results suggest that DVAB using an 8-G probe are feasible, safe and accurate. In our experience, clip placement was problematic. It is probable that increasing the dimensions of DVAB will only be relevant in a limited number of clinical situations, primarily the desire to obtain complete radiologic resections of the target abnormality.

Biopsy↗

PubMed2002

[Multifocal serous cystadenoma of the pancreas synchronous with ampullary adenocarcinoma].

Pancreatic cysts are common, but cystic tumors are uncommon. We report a rare case of serous cystadenoma of the pancreas synchronous with ampullary adenocarcinoma which supports a common etiopathogeny of these tumors. We discuss the differential diagnosis with mucinous cystadenoma which is potentially malignant and recall the microscopic and radiologic features.

Adenocarcinoma↗