Perceptual Experience of Visual Motion Activates hMT+ Independently From the Physical Reality: fMRI Insights From the Looming Pinna Figure.

The human motion processing area, hMT+, has been labeled the critical neural area for processing of real and illusory visual motion in radial 2D patterns. However, the activation in hMT+ during perception of illusory rotation in the looming double-circular Pinna Figure (PF) generated in 3D space has not been observed yet. To do so, an optic-flow like motion of rings (looming) in PF was generated on a computer screen. A psychophysically precise nulling procedure allowed quantifying the individual amount of the perceived illusory rotation in PF (PI) for each participant. The interpolation of the individual illusory motion parameters created a subjectively non-rotating PF and a physically rotating control stimulus of identical rotary strength as the PI. The physically rotating control was a double-circular figure which diverged from PF only in its arrangement of luminance gradients. In a 3-Tesla scanner, participants were presented with a random order of rotating and non-rotating figures (illusory, real, no rotation, and nulled PI). Both types, illusory and real rotation, when equal in perceptual strength for the observer, were found to be processed by hMT+.

Blood histamine and solid malignant tumors.

A clinical study was performed to determine whether patients with a newly diagnosed solid malignant tumor manifest an alteration in whole-blood histamine levels. Our results indicate that such patients have blood histamine nearly three times greater than either normal, healthy individuals or noncancerous disease controls. Following surgical removal of the tumor, blood histamine levels remained high for 2 months and then dropped close to the normal range 3 months after surgery. Basophil counts did not change significantly in the presence of a malignant tumor. Patients receiving either chemotherapy or radiation therapy, and terminal cancer patients who were no longer receiving any therapy except for pain control had blood histamine within or below the normal range. By analogy with animals studies, we suggest that nascent histamine synthesis is increased in the presence of a developing tumor. The clinical usefullness of this observation remains to be determined.

Linear increase in glycolytic activity through the cell cycle of schizosaccharomyces pombe.

The glycolytic activity of 3 different synchronous system in S. pombe was studied. Synchronous cultures were produced by a selection procedure, by cyclic heat treatment, or by cloning cells from an exponentially multiplying culture. In all experiments a complex medium with 3% glucose was used. The glycolytic activity was recorded with a gasometric method, the gradient diver. A single cell in exponential growth or a small number of synchronized cells were placed in ampulla divers in which the cells progressed undistrubed through a number of cycles. An ampulla diver is in principle a narrow pipette by which a single or a few cells are removed from the mother culture. It serves next as an axenic growth chamber and at the same time as a gasometer. The divers were placed in linear saline density gradients and the gaseous exchanges taking place in the divers resulted in migration of the divers. The migration rate is a measure of the glycolytic activity of the cells. Our results show that the glycolytic activity increases in a linear fashion between sucessive divisions. The rate of increase doubles at each division. This true in all 3 synchronous systems, and we take this as an indication that the cell cycles of heat-synchronized cells do not deviate seriously from the normal.