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D Khayat

Publications and source records attributed to D Khayat.

149 records · Page 9Linked to original sources
PubMedDate not supplied

Hibernoma, an uncommon tumor as a differential diagnosis of liposarcoma of the thigh.

Hibernomas are benign tumors derived from brown fat of hibernating animals and of human infants. The pathogenesis and malignant potential of hibernomas remain unclear. They occur generally in adults with a peak incidence in the third decade and with a predominance in women. However, the lesions may have an heterogeneous presentation that may mimic liposarcomas on MRI. Our report presents a case of hibernoma of the thigh whose the diagnosis initially suggested that it was a mixed liposarcoma with myxoid and well differentiated components.

Adipose Tissue↗
PubMedDate not supplied

A mesocolic leiomyosarcoma metastatic to the breast: case report and review of the literature.

This report describes a patient with mesocolic leiomyosarcoma, initially treated by excisional surgery. One year later the patient developed breast and hepatic metastases. To our knowledge, metastasis of leiomyosarcoma to the breast has not been previously reported in the literature. The discussion covers unusual sites for metastases of primary leiomyosarcomas and those tumors that most commonly give rise to breast metastases. Certain rare primary tumors of the breast related to the family of sarcomas are also brought to the attention of the reader. These may or may not have malignant characteristics. In the light of the differences in prognosis and treatment, recognition and precise diagnosis is of importance.

Breast Neoplasms↗
PubMedDate not supplied

Liposomal delivery of the herpes simplex virus thymidine kinase gene in glioma: improvement of cell sensitization to ganciclovir.

In this study, we investigated whether the regulation and the copy number of the herpes simplex virus thymidine kinase (HSVtk) gene increased the sensitization to ganciclovir (GCV) of glioma cell lines (Rat C6 and human U118-MG) using liposome-mediated gene transfer. Three recombinant plasmids carrying the HSVtk gene driven by the thymidine kinase promoter in single (pAGo) and double copy (pYED) or by the human cytomegalovirus promoter (pCMVtk) were used for the transfection. The DNA delivery was optimized by screening a panel of cationic liposomes using Lac-Z and luciferase as reporter genes. The efficiency of transfection reached 33% to 36% in vitro but only 18.6% in vivo after an intratumoral injection of DNA-liposome complexes. Moreover, after transfection of the three plasmids, the cell-killing effect of GCV was evaluated. A significant enhancement (four- to fivefold) of the cell sensitivity to GCV was shown in pCMVtk and pYED as compared with pAGo-transfected cells in both cell lines. According to the plasmid, the effect of the HSVtk/GCV system was confirmed by in vivo experiments and was objectified by a higher tumor weight reduction with pCMVtk (49%) than pAGo (27%). From these results, we conclude that (1) the gene transfer can be achieved by cationic liposomes both in vitro and in vivo and that (2) using this type of vector, the antitumor effect of the HSVtk/GCV system could be potentiated by the up-regulation of HSVtk gene duplication.

Animals↗
PubMedDate not supplied

Cytoskeleton alteration in MCF7R cells, a multidrug resistant human breast cancer cell line.

Various cytoskeleton modifications are associated with malignant cell transformation and have been used as prognostic factors. A human breast cancer cell line (MCF7S) and its multidrug resistant (MDR) subline (MCF7R) were characterized here for their intermediate filaments (IFs) expression (cytokeratin 8, 18, 19 and vimentin) as a function of their resistance phenotype. Modifications of these cytoskeleton molecules were analyzed by flow cytometry, immunofluorescence, electrophoresis and immunoblotting techniques. Cytokeratins 8 and 18 were similarly expressed in the cell lines. Cytokeratin 19 was expressed in the MCF7S cell line and not in the MCF7R variant, while vimentin was highly expressed in MCF7R and slightly in MCF7S. Analysis of IFs after the addition of doxorubicin (Dox) in the culture medium of MCF7S, showed an increase in cytokeratin 8 filaments. Vimentin expression in MCF7R was not modified in the presence of these different MDR modulators. Acquisition of MDR was associated with an increase and a redistribution of vimentin filaments characterized by a perinuclear polarization. These drug resistance associated changes might derive from different biological processes triggered by chemotherapy. In conclusion, this suggests that this intermediate filament could be a marker associated with chemoresistance or a marker of malignancy in certain epithelial cancers.

ATP Binding Cassette Transporter, Subfamily B, Mem↗