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Biomedical subjects

R Gilles

Publications and source records attributed to R Gilles.

114 records · Page 7Linked to original sources
PubMedDate not supplied

Importance of a post-therapeutic residue in the prognosis of head and neck rhabdomyosarcoma in children.

Enhanced contrast computed tomography (CT) was performed in 23 children treated for head and neck rhabdomyosarcoma (RMS). The CT studies were retrospectively reviewed by two senior radiologists. Analysis of these CT studies revealed to separate groups of patients. One group (12 patients) had a post-therapeutic residue defined as soft tissue thickening at the original site, which remained stable over a period of 3 months and caused no mass effect on adjacent structures. Of these 12, eight showed enhancement at the area of thickening. Nine of these 12 patients relapsed. The other group (11 patients) demonstrated no post-therapeutic residue; only three of these patients relapsed. In this study the presence of a post-therapeutic residue was significantly associated with a poor prognosis, using a Fischer's test (P = 0.04).

Adolescent↗
PubMedDate not supplied

Clustered breast microcalcifications: evaluation by dynamic contrast-enhanced subtraction MRI.

OBJECTIVE: Our goal was to evaluate dynamic contrast-enhanced subtraction MRI in the diagnosis of isolated clustered calcifications of the breast. MATERIALS AND METHODS: One hundred seventy-two patients underwent surgical biopsy for isolated clustered breast calcifications. Their mammograms showed round (n = 88) or linear/irregular (n = 84) microcalcifications. All patients had a preoperative Gd-DOTA-enhanced subtraction dynamic study. Any early contrast enhancement in the breast parenchyma concomitant with early enhancement of normal vessels was considered positive. RESULTS: Fifty-eight in situ carcinomas, 22 invasive carcinomas, and 92 benign lesions were found at histological analysis. Dynamic MR sequences showed early contrast enhancement in 76 of 80 malignant lesions (sensitivity 95%) and in 45 of 92 benign lesions (specificity 51%). Two invasive and two intraductal carcinomas did not show early contrast enhancement. Three independent observers agreed in rating early contrast enhancement in 143 of 172 lesions. CONCLUSION: Poor specificity limits the diagnostic accuracy of dynamic contrast-enhanced subtraction MRI in distinguishing benign from malignant microcalcifications on mammography.

Adult↗
PubMedDate not supplied

Comparative aspects of cell osmoregulation and volume control.

This brief overview considers the mechanisms of adaptation of animal cells to anisosmotic media in the framework of a comparative approach. Successful adaptation of animal cells to abrupt changes in the NaCl content of their environment depends on (1) mechanisms of osmolality and volume control and (2) the use of different organic molecules acting as 'compensatory osmolytes'. Up to now, the importance of this last process has been largely underestimated. It concerns the use of different organic osmolytes, aminocompounds and carbohydrates which can oppose or 'compensate for' the disrupting effects that changes in the intracellular level of inorganic ions can have on the organization and activity of different macromolecular structures. Contrarily to the cells of euryhaline invertebrates, most mammalian cells seem to lack the possibility to regulate effectively their content of organic compensatory solutes. Despite the presence of effective mechanisms of cell volume and osmolality control, they thus adapt only with difficulty to abrupt changes in the NaCl level of their environment. An interesting exception is the kidney medulla in which papillary cells seem to control easily the level of some selected amino compounds and carbohydrates. The use of these compensatory osmolytes enables them to cope with the rapid and sometimes important modifications in the NaCl level they are normally withstanding.

Animals↗