Immunomorphological characteristics of pleomorphic adenoma of salivary glands.

The immunohistochemical profile of 23 pleomorphic adenomas and 7 normal salivary glands was studied. We used antisera to vimentin (V), desmin (D), epithelial membrane antigen (EMA), prostate specific antigen (PSA), pancytokeratin, carcinoembryonic antigen (CEA), glial fibrillary acidic protein (GFAP) and S-100 protein. In the ducts and myoepithelial cells of normal salivary glands immunopositivity to most of the cytoskeletal proteins, EMA and CEA was observed. GFAP was localized only in cells of striated ducts. Major differences in the expression of various antigens among tubular structures, solid sheets, the myxoid and chondroid in the pleomorphic adenoma were encountered. Appearance of GFAP as a sign of stromal transformation into myxoid and chondroid was detected. Judging from these comparative immunohistochemical characteristics between normal salivary glands and pleomorphic adenomas, we assume that tumour cells originate from the reserve cells of intercalated and striated ducts.

Expression of cytoskeletal proteins and ATPase activity in bovine femoral artery and vein intima.

Intimal cells play an important role in the biology of the vascular wall. Variability in the metabolic activity of intimal smooth muscle cells (SMC), as well as the differential expression of cellular cytoskeletal proteins depend on factors such as degree of differentiation, aging, atherosclerosis, etc. Myosin ATPase activity and cytoskeletal proteins were studied in the intima of bovine femoral arteries and veins of mature animals. In some arteries the intima was thickened and two distinct layers--inner elastic hyperplastic (EHL) and outer, musculo-elastic (MEL) were observed. ATPase activity was well defined in endothelial cells (EC) as well as in SMC. However, differential enzymatic expression was observed in thickened intimas. SMC in the EHL were ATPase negative, while in the MEL they were ATPase positive. All EC and SMC in the "normal" intimas were vimentin positive, desmin and cytokeratin negative. In vessels with thickened intimas, the EHL showed intensive vimentin positivity; in the MEL desmin immunoreactive SMC were numerous as were as those in the media. Vimentin-positive SMC occupied their innermost part. Differences in the expression of ATPase activity and cytoskeletal proteins is discussed in terms of possible migration of medial SMC and/or morphological modulation observed in vessels with altered vascular walls.

Nitric oxide synthase (NOS) in the human umbilical cord vessels. An immunohistochemical study.

Localization of nitric oxide synthase (NOS) in endothelial cells of umbilical cord vessels and in cultured human umbilical vein endothelial cells was investigated by light and electron-microscopical (immunogold) immunohistochemistry. We observed localization of NOS-immunoreactivity in the majority (97%) of the endothelial cells of the umbilical vein and in a subpopulation (6.7%) of endothelial cells of the umbilical arteries. NOS was observed as well in the amniotic epithelium and in the cells of Wharton's jelly. Immunogold labelling in human umbilical vein endothelial cells dominated in the cellular matrix and was not associated with cellular organelles. Since human umbilical vessels are unique in lacking innervation, the functional significance of endothelium derived relaxing factor EDRF/NO in the local control of vascular flow is discussed.

Intermediate filaments and ATPase activity in the vascular wall of vertebrates.

The vascular wall of aorta and vena cava was examined for adenosine triphosphatase (ATPase) activity and cytoskeletal intermediate filaments (IF) in different representatives of vertebrates. Enzyme activity was studied by the modified method of Padykula and Herman. A streptavididin-biotin immunohistochemical method was applied to reveal desmin (D) and vimentin (V) IF. Endothelial cells of all vessels were V-positive and D-negative and exhibit high ATPase activity. Vascular smooth muscle cells (SMC) in lower vertebrates (pisces and amphibia) were also V-positive and D-negative, but showed low ATPase activity. SMC were D-positive and V-negative and possessed high enzyme activity in aves and mammals, similar to that of the endothelium. In cow vascular wall D-reactivity and high ATPase activity were mostly expressed in bundles of mosaically arranged thick SMC fibres of the outer aortic media as well as in the longitudinal fibres in the inferior vena cava. In higher vertebrates SMC of vasa vasorum were both V- and D-positive and showed high enzyme activity. The results demonstrate that D-immunoreactivity is mostly expressed in SMC of layers of high functional activity, which correlates with the intense ATPase reaction in these cells.

[Histochemical ATPase detection in arterial myocytes with regard to their contractile differentiation]. / Histochemischer ATPase Nachweis in arteriellen Myocyten mit Rücksicht auf ihre kontraktile Differenzierung.

ATPase activity of arterial medial smooth muscle cells in rabbits at different postnatal age was studied. At earlier periods the reaction was very weak in the media. This was followed by intensification after which it continues to be diffuse. Parallel electron-microscopic studies revealed a contractile differentiation which coexists with the activity of the 2 enzymes.