[Factors affecting the contralateral dose for the non-treated breast in irradiation following quadrantectomy]. / Fattori che influenzano la dose alla mammella non trattata nell'irradiazione dopo quadrantectomia.

We evaluated, with a treatment planning system, the maximum and the mean contralateral breast doses, and, with thermoluminescent dosemeters LiF100; the skin dose during radiation therapy after conservative surgery. The doses were correlated with technical parameters through statistical analysis. Since 1995, 100 patients have been considered, all of them treated with two 60Co tangential beams after quadrantectomy. The mean dose to the contralateral breast exhibited a statistically significant correlation with the gantry angle of the lateral (Pearson, p < .02) and medial beams (p < .01); the maximum dose was correlated with the gantry angle of the lateral (p < .002) and the medial beams (p < .002). In the last 50 patients, the skin dose (measured with TLDs) was correlated with: distance from beam edge (Pearson, p < .02), breast thickness (p < .01), gantry angle of the lateral beam (p < .005), gantry angle of the medial beam (p < .002). Furthermore, only the gantry angle of the lateral (p < .02) and of the medial beams (p < .01) exhibited statistically significant Spearman's correlation with skin dose. Wilcoxon's signed rank sum test for paired data was performed to study wedge dependence. The average contralateral breast dose using two wedges was statistically reduced with respect to the dose without wedges (p < .02). These results suggest that the dose to the contralateral breast could be significantly decreased by careful attention to the treatment details, which implies that the procedures related to the technical aspects of the therapy should be submitted to careful quality control.

Detection of inhibitors in chicken tracheal washings against Mycoplasma gallisepticum.

A chicken tracheal ring tissue-culture system was used to demonstrate that specific and nonspecific substances in chicken tracheal secretions inhibit the cilia-stopping effect (CSE) of Mycoplasma gallisepticum (MG). In chickens less than six weeks old, specific inhibitory substances were found in tracheal washings from chickens inoculated with MG. Nonspecific inhibitory substances were found in tracheal washes from untreated chickens seven weeks or older. Complement may play a role in the inhibition of CSE. Secretory immunoglobulin A was not detected in the tracheal washes.

An age-related coagulation disorder associated with experimental infection with infectious bursal disease virus.

Specific-pathogen-free White Leghorn chickens were inoculated with a field strain of infectious bursal disease virus. One group (A) was inoculated at 17 days after the chicks were hatched, and the other groups (C and E) were inoculated at posthatch day 42. Blood samples were obtained for determination of clotting times (whole blood recalcification, prothrombin, and activated partial thromboplastin times), virus-neutralizing antibody, and total hemolytic complement. There were significant increases in clotting times for groups C and E at 3 and 5 days after they were inoculated. There were no significant increases in clotting times at 3 days after inoculation in the group A chickens (inoculated at 17 days after hatching). There were no significant decreases in total complement activity in any of these chickens (groups A, C, and E). This study indicates that the mortality and clinical symptoms observed in chickens experimentally infected with infectious bursal disease virus may be associated with a clotting abnormality because it was noted only in chickens that developed severe clinical disease (inoculated at 42 days after hatching) and was not noted in chickens that remained clinically normal (inoculated at 17 days).