Lateral displacement as a response cue in the Titmus Stereo test.

Forty-nine subjects (ages 8-55) were tested with the circles and animals of the Tigmus Stereo test while wearing Polarid filters at axis 135 deg before both eyes so that the right eye's target was presented to both eyes. This procedure removed retinal image disparity as a cue to depth and left lateral displacement as the primary cue to obtain correct responses on the test. The subjects' scores on the circle test were much higher than expected by chance guessing. Different instructions to the subjects did not influence this result. Scores on the animal test were similar to those expected by chance. The subjects used lateral displacement as a response cue on the circle test but not on the animal test. Procedures for improving the validity of the Titmus Stereo test are described.     

ATYPICAL SEBORRHOEIC KERATOSIS*

Reports of eighteen eases of seborrhoeic keratosis showing varying degrees of cellular atypicality have been collected. It is almost certain that many more cases are filed under diagnoses implying malignancy. In common with similar lesions reported previously by various authors as malignant transformation, these lesions showed the characteristic pattern of seborrhoeic keratosis with, in addition, pleiomorphism, cellular anaplasia and abnormal mitotic activity in some degree. The lesions occurred predominantly in sun-exposed areas of patients who were over fifty years of age. Most lesions were of long duration. None of the lesions have shown any convincing evidence of malignant behaviour. It is suggested that the lesion should be regarded as an atypical seborrhoeic keratosis until more convincing proof of its malignant potential is established. Sun damage in ageing skin is suggested as being of possible aetiological significance in the development of epithelial cellular atypicality in seborrhoeic keratosis.     

The mechanism of actions of collagenase on the inhibition of release of acetylcholine from synaptosomal preparations.

The release of acetylcholine from synaptosomal preparations from bovine superior cervical ganglia and rat cortex was inhibited when the preparations were pretreated with collagenase. The inhibition of release could be overcome with the calcium ionophore A23187. Collagenase treatment was shown to inhibit the uptake of calcium into the preparations. In addition, gel electrophoresis of synaptosomal membranes revealed two missing high molecular weight proteins when either synaptosomes or synaptosomal membranes were incubated with collagenase.