Biomedical subjects
Publications and source records attributed to A Ispizua.
Rhabdomyosarcomas (RMS) are responsible for 5% to 10% of childhood cancers. In children, they are the most common sarcoma of the head and neck, urogenital tract, and limbs. We report a case of botryoid type rhinopharyngeal RMS in a 14-year-old girl which had a favorable outcome. The prognostic factors of RMS were reviewed.
Although cell polyploidization is not an infrequent event in mammalian cells and is common in tumours, the mechanisms involved are not well understood. Using the murine B16 cell line as a model, we evaluated the role of some key proteins involved in cell cycle progression: p34(cdc2), cyclin B1 and PCNA. By means of flow cytometry, we showed that both in modal- and in high-ploidy subpopulations, almost all cells were p34(cdc2)-positive. In the modal-ploidy subpopulation only 17.1% cells were cyclin B1-positive and 85.6% PCNA-positive; in contrast, in the high-ploidy subpopulation up to 91.8% cells were cyclin B1-positive and 97.3% cells were PCNA-positive (P < 0.001). Immunofluorescence microscopy showed that PCNA was located in the nucleus; p34(cdc2), both in the nucleus and cytoplasm; and cyclin B1 yielded a cytoplasmic spotted pattern with a perinuclear reinforcement. After a 24-h incubation with 3[H]-thymidine followed by withdrawal of the isotope, high-ploidy cells remained labelled 8 days after thymidine withdrawal, in contrast to modal-ploidy cells. Taken together, our results suggest that polyploid cells are not quiescent, their cell cycle is longer than that of the modal-ploidy population, and they maintain cyclin B1 throughout the cycle, which may contribute to their genesis by impeding the exit from mitosis.
It is well known the vocal pathology occurs more frequently in professionals using their voice than in the general population. Teachers form a particular group. We performed a study on 1.046 teachers in 1993 to quantify the percentage presenting a visible organic lesion of the vocal cords. We sent out a questionnaire on dysphonia and the professional vocal activity practised, and we performed a laryngeal examination with video-laryngo-stroboscopy. The results obtained evidence 218 cases of pathological exploration, i.e. 20.84% with a predominance of vocal nodules (43%) and Reinke oedema (18%). The analytical method and the results obtained are presented.
PURPOSE: The aim of the present study was to determine the role of DNA content in laryngeal epithelial lesions of different degrees of malignancy. PATIENTS AND METHODS: A total of 53 lesions were studied, which included five benign tumors, 18 dysplasias, and 30 carcinomas of different degrees of differentiation and clinical stage. In all cases, the DNA content was determined by microspectrophotometry of paraffin-embedded Feulgen-stained biopsies. RESULTS: We found significant differences between the DNA-content histograms corresponding to each lesion group studied. Of special interest was the transition from moderate to severe dysplasia (characterized by a striking increase in the G2M-phase cells) and the transition from severe dysplasia to carcinoma (characterized by a brusque change in the modal ploidy of the lesion). CONCLUSION: The determination of DNA content, and study of DNA histogram, will help to assess degree of malignancy in epithelial lesions of the larynx.
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