Biomedical subjects

O Duquenne

Publications and source records attributed to O Duquenne.

3 recordsLinked to original sources

PubMed1997

Solid phase cytometry allows rapid in situ quantification of human papilloma virus infection in biopsy material.

Solid phase cytometry would be an asset for many histological and cytological studies. Current microscope-based cytometers and image analysis systems are too slow to analyze specimens several millimeters wide. We have recently shown that a rapid wide area laser scanning device that operates on solid supports has a linear response. We assess it here for solid phase cytometry. Each cell detected by the cytometer can be automatically positioned for visual observation in the field of an epifluorescence microscope (conventional or confocal) in which the stage is driven by the instrument's computer. We were able to detect and map human papillomavirus-infected cells labeled by fluorescent in situ hybridization in cervical condyloma biopsies. We could quantify the fluorescence emitted by these cells and show differences of up to 35-fold in fluorescence intensity between individual cells. These differences in intensity might reflect differences in viral copy number. The potential of the system to provide fast, reliable and reproducible analyses of solid tissue samples is discussed.

Biopsy↗

PubMed1995

Tat-induced lesions in transgenic mice do not correlate with the HIV-1 LTR transactivation.

The product of the tat gene is the most potent transcriptional trans-activator of the HIV-1 LTR (Human Immunodeficiency Virus type 1 Long Terminal Repeat) and might be predicted to be one of the HIV-1 proteins involved in the pathogenesis of AIDS-associated tumors. Deciphering its role in vivo may imply generation of transgenic mouse models displaying different spectra of tat expression. However, it remains difficult to correlate the mRNA expression, the protein production and the eventual pathological consequences in the animal. Our goal in this work was to elaborate a binary transgenic system allowing such an approach, the correlation of the transgene expression in different tissues and the production of the Tat protein, tested as a trans-activator in vivo, with its pathogenic effects. No direct linkage was evident between the degree of transactivation and pathogenesis. Indeed, only benign lesions were observed in malpighian epithelia, where the production of the Tat protein was clearly evidenced by its transactivating property.

Animals↗

PubMed1994

[Extraosseous Ewing's sarcoma with thoracic localization].

We report two cases of extraosseous Ewing's sarcoma revealed by large volume thoracic tumour lesions, occurring in a clinical context of an alteration in general health. The tumour mass was occupying the upper half of the left hemithorax, and was invading the thoracic wall posteriorly in the first case; it occupied the whole of the right hemithorax with invasion of the first three ribs in the second case. The first patient received five treatments with chemotherapy, using cyclophosphamide in association with adriamycin, which led to a partial response and was completed with surgical excision and a further five doses of chemotherapy using cyclophosphamide in association with etoposide. Subsequently radiotherapy was given. There was an unfavorable outcome, with recurrence in the 13th month. The second patient received three courses of chemotherapy using cyclophosphamide in association with actinomycin D and vincristine, which allowed for an 80% reduction in the tumour volume. Surgical resection was then carried out, followed by five courses with the same chemotherapy protocol. Forty-two months after the diagnosis this patient remained in complete remission. These two cases enable us to stress the value of associating a chemotherapy protocol consisting of cyclophosphamide, actinomycin D and vincristine, with systemic surgical excision in tumours with a high potential for development.

Adult↗