A method for staining reticulum and red cells in hematopoietic tissues of lower vertebrates.
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Amido Black↗
Biomedical subjects
P Gorgollón
Publications and source records attributed to P Gorgollón.
Fine structure of canine thymus.
Normal thymuses of young-to-adult healthy dogs have been studied with light and electron microscopy. Two well-defined zones are observed both in the medulla and in the cortex. In the outer cortex including the subcapsular region, reticular cells and mitotic lymphoblasts are more numerous than in the inner cortex, whereas in the central portion of the medulla the small proportion of free lymphoid cells is more evident than in the outer medulla. Reticular cells can be classified into two main groups according to some morphologic features: epithelial and mesenchymal. Epithelial reticular cells seems to undergo a gradual transformation from the subcapsular region to the medulla, and finally they may become heterogeneous Hassall corpuscles. Mesenchymal reticular cells are represented by macrophages and dendritic-like cells. The latter cells are located in the inner medulla and fill the intercellular spaces with their long cytoplasmic processes. In some occasions these processes appear degenerated and plasma cells and eosinophilic leucocytes are found. This fact suggests different functional stages and a possible participation of the normal thymic medulla of the adult dog as a peripheral lymphoid organ.
Animals↗
The normal human appendix: a light and electron microscopic study.
Human appendices from 3 to 12 years old children were studied by light and electron microscopy. Three morphological zones were determined: sub-epithelial (or lymphoid lamina propria), parafollicular, and follicular. The fine structure of these regions has been studied and discussed with regard to the thymus-dependent and thymus-independent regions of other lymphoid organs. Two types of lymphocytes, 'light' and 'dark', and intermediate forms, were also found. The light ones are the more abundant in the epithelium and within the parafollicular post-capillary venules; they form groups or clusters between epithelial cells, becoming like blast cells and possibly maturing into plasma cells in the sub-epithelial region. Whether light lymphocytes are T or B or both is discussed. The general conclusion is that the human appendix, at least in children, has the characteristics of a well-developed lymphoid organ, suggesting that it has important immunological functions.
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