0000000000171227
AUTHOR
Paul J. Mcmillan
Third International Congress of Histochemistry and Cytochemistry
The tissue distribution of enzymatic activities in intestinal metaplasia stomachs exhibiting chronic gastritis was compared histochemically with that of the small intestine in man.
Improvement of the butyl methacrylate-paraffin embedment.
The excellent butyl methacrylate-paraffin method as an embedment for light microscopy has been technically improved. More uniform and reproducible polymerization has been obtained by using a vacuum oven to degas the polymerizing mixture and to replace the air with nitrogen at 650 Torr. The amount of benzoyl peroxide required must be determined for each batch of butyl methacrylate. A teflon lined, reusable metal mold and a method of one-step blocking of tissues in preparation for sectioning are also described.
"Synaptic" ribbons and spherules of the guinea pig pineal gland: inverse day/night differences in number.
The present study deals with the functionally enigmatic "synaptic" ribbons and spherules of guinea pig pinealocytes. Whereas the ribbons have been shown to exhibit a 24-hr rhythmicity with low numbers during the day and high numbers at night, very little of a definitive nature is known about the spherules. Sixteen male guinea pigs of the Hartley strain were perfusion fixed, 8 between 0900-1100 hr, and 8 between 2100-2300 hr. The ribbons and spherules were counted in the pineal parenchyma of the proximal, intermediate, and distal regions. In confirmation of earlier studies, it was found that "synaptic" ribbons are equally abundant in the proximal, intermediate, and distal regions of the glan…
Anomalous occurrence of immunoreactive calcitonin cells in the thymus of the rat.
In a study of the effect of pinealectomy on thyroid C-cell number, 8 animals out of 66 were found to have thymic tissue in close association with the thyroid. Cells containing immunoreactive calcitonin were found in all of the thyroids but in only one of the 8 pieces of thymus. These cells found in a piece of thymic tissue associated with the right thyroid lobe were located immediately under the capsule and did not form or associate with follicles. Unlike the other animals the rat with thymic calcitonin cells had an unequal distribution of C-cells between the left and right thyroid lobes, but the total number of thyroidal C-cells was the same as that of the other rats. Since the thymus prop…
Number and size of rat thyroid C cells: No effect of pinealectomy
A method for the estimation of the size and total number of calcitonin-containing cells (C cells) in the rat thyroid gland has been devised. The total area, the number of C cells per unit area, and the areal fraction of C cells were determined for the C cell region using step serial sections. From these data it was estimated that from 0.3 X 10(6) to 1.0 X 10(6) C cells were evenly divided between the two thyroid lobes. Approximately 150 micron3 of cytoplasm were associated with each of these cells. In comparison with sham-operated rats, pinealectomy had little effect on the number of C cells. In an experiment terminated in the summer, there was a statistically insignificant decrease 6 weeks…