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F Guedea

Publications and source records attributed to F Guedea.

24 records · Page 2Linked to original sources
PubMed1991

Primary subglottic cancer: results of radical radiation therapy.

Between October 1964 and December 1985, six patients with primary squamous cell carcinoma of the subglottis were treated with radical radiation therapy at the University of Florida. The disease was staged as Tis (one patient), T2N0 (two patients), and T4N0 (three patients). Local control was achieved with irradiation in four patients (66%) who were observed for 3.5, 4, 4, and 5 years after radiation therapy. Two patients whose tumors recurred at the primary site underwent salvage laryngectomy, which was successful in one patient.

Aged↗
PubMed1990

Chromosome instability in bladder carcinoma patients.

The relationship between the presence of a high frequency of chromosome aberrations and a predisposition to cancer has been well established in the so-called chromosome instability syndromes. Chromosome instability is also present in a variety of patients affected by cancer, and sometimes in their healthy relatives. We present a cytogenetic study carried out in lymphocytes from 13 untreated bladder carcinoma patients (only four of them had a history of occupational exposure to mutagens). Percentages of aberrant metaphases were significantly higher in cancer patients than in controls. Of the total number of chromosome aberrations in cancer patients, 67.16% corresponded to major structural chromosome abnormalities, while 25.37% were gaps or breaks. Numerical abnormalities represented 7.46% of the total. The bands more frequently involved in chromosome rearrangements were 5q31 and 1q32. Our results tentatively indicate that a significant proportion of patients with bladder carcinoma may have an underlying inherent chromosome instability. An age effect cannot be excluded, but we did not find significant differences between patients over 50 years of age and patients under 50 years of age.

Adult↗
PubMed1990

Cytogenetic effects of radiotherapy: frequency and types of chromosome aberrations.

The frequency and types of chromosome aberrations induced by ionizing radiation in cancer patients were evaluated in 24 cases studied just before and immediately after radiotherapy. The incidence of aberrant metaphases prior to treatment was 9.98% and increased significantly after treatment to 32.8%. The frequency of chromosome aberrations before radiotherapy was, with the exception of the cases of breast cancer and seminoma, significantly higher than that in our laboratory controls. A comparison of chromosome abnormalities observed before and after treatment indicated that dicentric translocations, rings, and reciprocal translocations increased by a factor of 23, 13, and 11, respectively, after radiotherapy. Ionizing radiation produces more asymmetrical than symmetrical chromosome aberrations and more two-break than one-break anomalies.

Adult↗
PubMed1989

Cytogenetic effects of radiotherapy. Breakpoint distribution in induced chromosome aberrations.

A total of 660 breakpoints were identified in the chromosome aberrations detected in lymphocytes from cancer patients after radiotherapy. The results show that chromosomes 1, 3, and 7 were significantly more affected than other chromosomes by ionizing radiation in vivo. Chromosome arms 1p, 1q, 7q, and 11p were also significantly more affected. Some bands also showed a special sensitivity to radiation, and band 1q32 was the most affected. This band is proposed as a "hot point" for the clastogenic effect of ionizing radiation. A significant clustering of breakpoints in G bands was also found, especially at the telomeres, as previously described by other authors. Clustering of breakpoints was also observed in bands where fragile sites, protooncogenes, breakpoints involved in chromosomal cancer rearrangements, and breakpoints involved in chromosomal evolution of the Hominoidea are located.

Adult↗
PubMedDate not supplied

Radiotherapy for chemodectoma of the carotid body and ganglion nodosum.

Chemodectomas of the carotid body and of the glomus vagale are uncommon tumors of the head and neck. Between 1981 and 1986, 6 patients with advanced chemodectomas of either the carotid body (5 patients) or the glomus vagale (1 patient) were treated with radiotherapy at the University of Florida. Tumors were bilateral in 2 patients. Five patients have had no evidence of disease progression for 5, 5.5, 7, 7, and 8.5 years following irradiation. One of the 5 patients experienced complete regression, 2 noted partial regression, and 2 remained stable (without progression). One patient, who had received 2 prior operations and a course of irradiation at another institution, died of locally recurrent disease 5 years after re-irradiation at the University of Florida. No patient experienced a significant complication secondary to irradiation.

Adult↗