Intravascular brachytherapy physics: report of the AAPM Radiation Therapy Committee Task Group no. 60. American Association of Physicists in Medicine

Recent preclinical and clinical studies indicate that irradiation using ionizing radiation in the dose range of 15 to 30 Gy may reduce the occurrence of restenosis in patients who have undergone an angioplasty. Several delivery systems of intravascular brachytherapy have been developed to deliver radiation doses in this range with minimal normal tissue toxicity. In late 1995 the American Association of Physicists in Medicine (AAPM) formed a task group to investigate these issues and to report the current state of the art of intravascular brachytherapy physics. The report of this task group is presented here.

[Idiopathic proctocolitis. Follow-up (1-13 years) of 71 patients]

Follow-up was possible in 71 of 74 patients with idiopathic proctocolitis diagnosed and/or assisted at the Department of Gastroenterology of the Centro Policínico de Almada, between 1973 and 1985. The aim of the present study was to verify the natural history of the disease and if there were statistically significant differences depending on the extension of the disease (proctitis versus colitis). Complications were present in 22 patients (31%): peri-anal (10%), local or intestinal (24%) and extra-intestinal (28%). Fifteen patients (21% of the cases) had hospital admission at least once, and 2 of them (3%) were submitted to surgery. No cases of cancer of the colon and rectum were detected and mortality was nil. Forty-one patients (58%) were assymptomatic at the last observation (45% with colitis and 75% with proctitis). There were statistically significant differences between the group of patients with ulcerative colitis and that of proctitis concerning the total number of complications (p less than 0.001), local complications (p less than 0.01), extra-intestinal complications (p less than 0.05), need for hospital admission (p less than 0.001) and absence of symptoms at the time of last observation (p less than 0.05), thus confirming a better prognosis of the disease when only the rectum is involved.

Left-hemisphere language lateralization in bilinguals: use of the concurrent activities paradigm

Previous visual and auditory lateralization studies have demonstrated that the languages of bilinguals are lateralized to the left hemisphere to the same extent as in monolingual controls (C. Soares & F. Grosjean, 1981, Perception and Psychophysics, 29, 599-604; C. Soares, 1982, Neuropsychologia, 20, 653-659). The present study tested the same group of Portuguese-English bilinguals and a group of English-speaking monolinguals on a series of concurrent activity, or time-sharing, tasks. Greater levels of disruption in finger tapping with the right hand than with the left hand occurred during the performance of those tasks which required overt speech production, and this for both bilinguals and monolinguals. As in the previous studies, there were no lateralization differences across the bilinguals' two languages or between bilinguals and monolinguals. Thus, further evidence for equal levels of left-hemisphere dominance for language in bilinguals and monolinguals was provided by the use of the concurrent activities paradigm.

Clausal intonation after unilateral brain damage

Thirteen right-handed adult speakers, including five patients with unilateral left-hemisphere damage, four patients with unilateral right-hemisphere damage, and four patients with non-neurological damage, read aloud sentences designed to test influences of clause and utterance length on two acoustical measures of intonation, fundamental voice frequency ( Fo) and timing. Patients with unilateral damage to the left-hemisphere exhibited more abnormality in Fo and speech timing than did patients with right-hemisphere damage.

The influence of inter- and intra-speaker tempo on fundamental frequency and palatalization

A study was conducted to examine the influence of speaking rate and emphatic stress on patterns of fundamental frequency (F0) and palatalization across word boundaries. Two groups of speakers, exhibiting characteristically fast versus slow speech, uttered preselected sentences at normal, fast, and slow rates. Acoustic analysis of F0 showed somewhat higher F0 peaks for characteristically fast speakers and for fast rates of speech. Emphatic stress was accompanied by a typical heightening of F0 on the emphasized word and by a lowering of F0 on a neighboring word. Palatalization across word boundaries was more frequent among characteristically fast speakers and at fast rates of speech. In addition, palatalization was more frequent in the absence of emphatic stress at the key site. The results for F0 were discussed in terms of the influence of vocal fold tension, while the results for palatalization were discussed in terms of the incompatibility of phonological processes of lengthening versus shortening as well as possible look-ahead restrictions.

Converging evidence for left hemisphere language lateralization in bilinguals

A previous study [1] demonstrated that when subject and experimental variables are controlled, similar levels of left hemisphere language lateralization are obtained in bilinguals and monolinguals. The present study used the same group of bilinguals (adult, late acquirers of their second language) in an auditory lateralization task. A similar degree of left hemisphere asymmetry was again obtained for the bilinguals' two languages and for the monolinguals. Furthermore, the individual performances of the bilinguals--within the present task and across visual and auditory tasks--paralleled those of monolinguals. Thus, converging evidence is provided for equal levels of left hemisphere language dominance in bilinguals and monolinguals.