Hi everyone:

We have noticed "bubbles",  round white spaces, in our brain tissue 
sections. They do not occur in the gray matter; only in the white 
matter, and are more concentrated in the dense white matter of the 
cerebral peduncle than the white matter of the cortex. I 've thought 
that it could be a processing/infiltration problem. White matter may be 
denser than gray, and have a slower infiltration rate. That might 
explain the bubbles only being found in the white matter. However, not 
all batches of cases show bubbles;  the latest batch showed very few, 
although they were still present. Any thoughts? Thank you

Tim Wheelock