The effect of varying stimulus rate and duration on brain activity during reading

The effect of the presentation rate and exposure duration of visually presented words on brain activity was investigated using positron emission tomography. Subjects either read aloud or silently mouthed the names of words. In regions associated with early visual analysis, activity increased with both rate and duration; in regions associated with response generation, activity increased with increasing rate but was unaffected by duration; and in regions associated with word recognition, activity decreased with increasing duration. The variable responses of different brain regions illustrate the functional segregation of these regions. Of particular interest was the dissociation between activity in the posterior fusiform gyri and that in the medial lingual gyrus--in the former, activity increased with rate and duration but the latter was unaffected by either variable. This finding suggests that word processing in the lingual gyrus during reading is distinct from that in the posterior fusiform gyri. A further observation was that during reading aloud, when subjects can hear the sound of their own voice, the response in the primary auditory cortices increased with stimulus rate, demonstrating that subjects process the sound of their own voice in a qualitatively similar way to words spoken by another.     

Effect of radiation and contrast media on chromosomes. Preliminary report

Measurements of chromosome aberrations or micronuclei in lymphocytes obtained from 7 patients indicate that angiocardiography produced chromosome damage corresponding to an average absorbed dose of about 50 rads. This is an order of magnitude larger than was estimated from the exposure rate. Experiments on lymphocytes suspended in solutions of methylglucamine and sodium diatrizoate (Renografin) or sodium diatrizoate alone (Hypaque) indicate that the chromosome damage observed in the patients is due in larger part to two effects: (a) an increased absorption of x rays as compared to blood and (b) a breakage of chromosomes even in the absence of x rays.     

Acute scrotal swelling in Henoch-Sch?nlein syndrome

Freeman-Sheldon's syndrome is a rare genetic disease inherited as an autosomal dominant trait in some families but showing sporadic appearance in the majority of the reported cases. In the present paper we report a family having two affected children from normal consanguineous parents suggesting that Freeman-Sheldon's syndrome may be heterogeneous from the genetic point of view.