The effect of orientation on the clarity of Hermann grid illusory lines.

To test the hypothesis that Hermann grid illusory lines are most clear when the grid is presented at a 45 deg, each of 20 participants underwent 10 trials in each of two conditions ('make the lines least clear' and 'make the lines most clear') which were run using a method of adjustment. A matched-pairs t-test applied to the means of the two conditions was significant beyond the 0.01 level. One-group t-tests supported the claim that the illusory lines are least clear for a vertical/horizontal orientation of the grid and most clear when it is rotated 45 deg. The results substantiate, in a systematic manner, 70 years of claims about the effects of grid orientation on illusory line clarity.     

Changes in nonspecific lymphoid (NK,K, T cell) cytotoxicity following BCG immunisation of healthy subjects

Summary Nonspecific cytotoxicity was investigated in five healthy subjects following a single BCG immunisation (day 0). A decline in white cell, lymphocyte, and monocyte counts occurred at day 2, followed by increases back to baseline levels. Lymphoid NK, K, and to a lesser extent T cell cytotoxicity exhibited a similar pattern in the five subjects; a decrease at day 2, followed by recovery by day 7. An overshoot on days 10 and 14 for NK cytotoxicity was then observed, with ADCC activity still significantly increased at day 21. A decline towards baseline values was seen at day 28. The implications for immunotherapy scheduling are discussed.