The spectral sensitivity of the visual system upon adaptation by white light at intensity of 10,500 td was studied in Maxwellian view. The monochromatic stimuli had a size of 8 degrees and duration ...of 700 ms. They were superimposed on an adaptation field of 14 degrees. The spectral sensitivity was determined by the off-VEP amplitude measured from the negative peak with a latency of 75-80 ms to the positive peak with a latency of 100-110 ms. The EEG was led off monopolarly from the occipital scalp area. Eight normal trichomats, 2 protanomalous and 2 deuteranomalous subjects were investigated. Some specificity of the spectral sensitivity curve, determined by the VEP amplitude, were studied. Special attention was placed on the sensitivity decrease between lambda = 550 nm and lambda = 590 nm, which was much pronounced in the normal trichomats. Maximum sensitivity was observed at lambda = 527 nm. The sensitivity at lambda = 578 nm was lower than the maximum one by 0.8 logarithmic units or more. It is assumed that this sensitivity decrease is a manifestation of opponency between the middle wavelength and long wavelength mechanisms. In the anomalous trichomats the sensitivity decrease between lambda = 550 nm and lambda = 590 nm was much less pronounced. Maximum sensitivity was obtained at lambda = 551 nm. In the long wavelength range of the spectrum the deuteranomalous subjects showed a higher sensitivity as compared to the protanomalous ones. The obtained results suggest disturbances of color opponency in the anomalous trichomats.
Three cases are reported of pseudarthrosis of the scaphoid bone which have been treated by distraction with an external fixator employing ligamentotaxis. The investigations of Ilizarov and ...collaborators are discussed, pertaining as they do to stimulation of osteogenesis by distraction. Also considered are the possible indications for use of the method in some unfavourable fresh fractures of the scaphoid.
Ten cases with lengthening of one of the fingers (as opposed to the thumb) are reported out of which nine were lengthened at the proximal phalanx and one at the middle. A small distraction device has ...been utilized, based on the principle of Ilizarov's apparatus with some alterations necessitated by the small size and specific requirements of the hand. The lengthening achieved varies from 1.2 to 3.2 cm, and after it has been accomplished, osteoplasty with bone graft has been performed in all cases. The results obtained are considered to be good both from the functional and the cosmetic point of view.
Averaging of EEG recorded monopolarly from C3, contralateral to the activated limb, in the stretch reflex shows the presence of somatosensory evoked potential (SSEP) with characteristic shape: four ...constant waves--P29, N84, P202 and N294, and four inconstant waves--N31, P74, P99 and N123. Comparison of this SSEP with the SSEP in children, evoked in the stretch reflex, shows shorter latencies of the waves in adults. On the basis of data from the different series of experiments, it is assumed that kinesthetic signalization plays a dominant role in the genesis of SSEP of the T-reflex. Studies have shown that SSEP of the T-reflex is succeptible to habituation upon long repetition of the stretch reflex.
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