2,5-Di-t-amyl-p-benzoquinone: an antioxidant encountered during the analysis of human tissues.

The title compound was found in extracts of several human tissues, including neurological tumors, adult brain and fetal brain. It was also present in adhesive tapes used in the laboratory to label glassware, but not in sufficient quantities to be responsible for contamination of the tissues. No source of contamination was found in the hospital. One possible source is an antioxidant used in rubber manufacture. Analytical data are also given for related benzoquinones and hydroquinones.

A method for enumeration ot T and B lymphocytes in tissues.

A method for the identification of T and B lymphocytes in tissue specimens is described. A sonication technique results in viable relatively pure lymphocyte populations which are easily classified by their surface markers. This readily reproducible method can become a standard laboratory procedure in the evaluation of disease states which require such information related to the classification of lymphocyte cell origin.

Horseradish peroxidase labeled antisera--a diagnostic method for evaluating the percentages of B lymphocytes in peripheral blood.

Horseradish peroxidase labeled antisera supplied commercially was used to evaluate B lymphocytes in peripheral blood. This technique not only gave comparable results to the conventional fluorescein method, but also proved to be more advantageous.

Effect of lid suture on retinal ganglion cells in Macaca mulatta.

Previous work has established the pronounced effect of unilateral lid suture during visual immaturity on cell growth in the lateral geniculate nucleus of cats, dogs and monkeys. Most investigators have reported the retinas to be grossly normal but only a few quantitative studies are available and the results are contradictory. We have compared cell section diameters and cell density of parafoveal retinal ganglion cells in the deprived and non-deprived eye of Macaca mulatta after the lids of one eye were studied between the ages of 1-9 weeks for varying periods of time. The results show a decrease in the size and density of parafoveal retinal ganglion cells after long-term (24 months) visual deprivation. Lid suture of lesser duration (2-56 weeks) had no effect on the size of retinal ganglion cells.

Histology of the monkey lateral geniculate nucleus after unilateral lid closure and experimental strabismus: further observations.

The histology of binocularly and monocularly innervated portions of the lateral geniculate nucleus (LGN) was studied after unilateral lid closure and experimental esotropia and exotropia in the Macaca mulatta and the results were compared with behavioral and neurophysiological data. The most severe cell shrinkage occurred in two animals who had one eye sutured during the first week of life; all dorsal and ventral deprived LGN layers, including the monocular segment, were involved. Less severe anomalies and sparing of the monocular segment were encountered in esotropic amblyopic monkeys and the least severe changes were in exotropic animals without amblyopia. The severity of behavioral, neurophysiologic, and histologic changes following unilateral lid suture or experimental strabismus could be correlated in all animals studied. The data indicate that the order of susceptibility of the LGN to reduced or abnormal visual input early in life appears to be: dorsal laminae greater than ventral laminae greater than monocular segment.

Histological observations in the normal monkey lateral geniculate nucleus.

As a basis for studies of the histologic effect of visual deprivation, cell section areas were determined in all six laminae from the anterior, central, and posterior regions of both lateral geniculate nuclei (LGN) from a normal macaque monkey. No significant cell size variations existed between the right and left LGN's, between the contiguous parvocellular and magnocellular laminae of the same LGN, and between parvocellular sizes in varous regions of the LGN's. In the magnocellular laminae, cell section areas increased in an anteroposterior direction.