Chlorpromazine modulates the morphological macro- and microstructure of endothelial cells.

Chlorpromazine (CP), an amphipathic, antipsychotic agent, causes concave membrane bending in red blood cells with formation of stomatocytic shapes by modulation of the phospholipid bilayer. This study was designed to investigate the effects of CP on the shape of bovine aortic endothelial cells (BAEC) and their membranes in confluent monolayers with phase-contrast and transmission electron microscopy. Exposure of BAECs to nanomolar levels of CP leads to membrane curvature changes. With increasing CP concentrations, the membrane assumed a shape with enhanced numbers of intracellular caveolae and projection of pseudopodia at all junctions. At higher CP concentrations (up to 150 microM), the endothelial cells assumed almost spherical shapes. The evidence suggests that CP may affect lipid bilayer bending of BAECs in analogy with previous observations on erythrocytes, supporting the formation of caveolae and pseudopodia in BAECs due to the induction of concave membrane bending, as well as an effect on endothelial cell membrane adhesion at higher CP concentrations with loss of cellular attachment at junctions.

A cytogenetic approach to the differential diagnosis of metastatic clear cell renal carcinoma.

AIMS: To determine by cytogenetic analysis the origins of two clear cell tumours in a 70-year-old Caucasian woman, one in the thyroid gland, and the other in the skin, 16 and 20 years, respectively, after tumour nephrectomy. We sought a conclusive distinction between primary clear cell thyroid carcinoma and its cutaneous metastasis, and between thyroid and cutaneous metastases of clear cell renal carcinoma (RCC). METHODS AND RESULTS: Paraffin sections of the previously formalin-fixed thyroid tumour, and the fresh cutaneous tumour were stained with haematoxylin and eosin (H & E) and periodic acid-Schiff (PAS). Additionally, samples of both tumours were examined electron microscopically. Immunohistochemistry was performed with antibodies against thyroglobulin, pancytokeratin, keratin 7, 8, 18 and 19, chromogranin, calcitonin, CEA, vimentin and EMA. Five to six micrometre sections of both tumours were analysed with alpha-satellite probes of chromosomes 3, 7 and 17 using chromosomal in-situ hybridization (CISH). The cutaneous tumour was also cultured and analysed cytogenetically. The thyroid tumour displayed some follicle-like structures that stained positive with both PAS and antithyroglobulin, giving evidence of possibly entrapped thyroid follicles in metastatic RCC. The cutaneous tumour was negative for both stains. The tumours were ultrastructurally completely devoid of neurosecretory granules. Classical cytogenetical analysis of the cultured cutaneous tumour cells revealed monosomies 3 and 14, well-known specific primary and secondary aberrations, respectively, in clear cell RCC, and hitherto not reported in thyroid carcinomas. CISH of both tumours revealed monosomy 3, indicating a cytogenetical correlation between them. There was no evidence of typical chromosomal aberrations for thyroid carcinomas like structural changes on 10q, structural rearrangements or translocations of chromosome 7. CONCLUSION: Although neither histological sections, nor paraffin blocks of the original nephrectomy specimen were available for review, the original tumour was on record as clear cell RCC. Therefore the two tumours' renal origin was confirmed.

Alteration of vascular endothelium and endothelium smooth muscle interaction after carbogen gas perfusion of isolated rat and guinea pig heart.

The aim of the study was to alter the vascular endothelium of the mammalian myocardium with respect to coronary flow regulation and vascular permeability. For this purpose, carbogen gas perfusion (GP) of Langendorff-type isolated rat and guinea pig heart was chosen. Perfusion of the hearts with carbogen gas was possible, as well as replacement of the GP by fluid perfusion. The energetic and mechanical state, the creatine kinase release, and the electron microscopic examination of the rat heart indicated only a moderate to minimal alteration of the cardiomyocytes after GP. As a result of GP a massive alteration of the vascular endothelium could be demonstrated in the rat heart, based on the release of the cytosolic endothelial marker enzyme, purine nucleoside phosphorylase, the partly altered vascular permeability and the morphologically detected endothelial damage to arterioles, capillaries and venules. Moreover, the reduced coronary flow response to short periods of anoxia (rat, guinea pig) and the inverted flow response to serotonin administration with maintained response to sodium nitroprusside (rat) in the post-gas perfusion period reflected an alteration of endothelial smooth muscular interaction in the rat and guinea pig heart. Furthermore, the distensibility of the coronary vasculature was increased in the rat and guinea pig heart in the post-gas perfusion period, where a relative autoregulatory behavior was maintained (rat) or partly maintained (guinea pig) in passively predilated vessels. In conclusion, carbogen gas perfusion of isolated hearts allows to induce preferred alteration of endothelium and endothelium-smooth muscle interaction.

Interactions between bladder tumor cells as tumor spheroids from the cell line J82 and human endothelial cells in vitro.

Multicellular tumor spheroids (MCTS) are a reliable model of nonvascularized tumor cell aggregates showing a well defined three-dimensional growth pattern and are comparable with small metastatic cancer cell complexes in blood circulation. In the present study we have established a co-culture system of multicellular bladder tumor spheroids with human endothelial cells on extracellular matrix (ECM) in order to investigate morphological and proliferative changes of endothelial and tumor cells within a defined time of cell-cell interaction. The MCTS--endothelial cell--extracellular matrix complex was observed within coculture periods from 1/2 to seven days. Morphological changes (light microscopy, scanning and electron microscopy) indicated that MCTS are not influenced by cocultured endothelial cells. The tumor cells invaded into the ECM after degradation of endothelial cells in the center of the contact zone. Endothelial cells, however, showed degenerative changes as well as a complex reaction in their proliferation activities. We could recognize an initial increase of proliferation of endothelial cells next to the MCTS. Later on, endothelial cells next to invading tumor cells showed changes in morphological polarity. The model system used has the advantage of using human tumor tissue. It distinguishes between basic cellular mechanisms like adherence, migration, DNA synthesis and proliferation in the study of the contact of tumor cells and vascular endothelial cells as an important event in hematogenous tumor spread.

Application of scanning electron microscopy to diagnostic pathology. A critical review.

A survey with critical comment of the present state of SEM knowledge is given for those internal organs that are most important for the surgical and anatomical pathologist. With the exception of microanalysis, today SEM does not aid diagnosis by the pathologist because the SEM results are, at present, not certain enough to justify their application to a diagnosis with clinical consequences where the same results can be obtained by the accustomed LM and TEM with their respective adjuvant techniques like histochemistry or immune histology. In the future, SEM will only be established as an essential diagnostic tool when SEM reveals hitherto unknown morphological patterns which can be related to clinical syndromes; some suggestions are made where this can be achieved.

The endothelial surface of large veins of rabbit: scanning electron microscopic observations.

The following veins of the rabbit were fixed by perfusion and studied systematically by scanning electron microscopy: sagittal sinus, confluence of sinuses, external jugular vein, superior vena cava, inferior vena cava, greater saphenous, and femoral veins. One result is that the shape and arrangement of endothelial cells of the veins are obviously influenced by hemodynamic shear forces. Two types of subendothelial fibres were demonstrated: "cross-fibers" which correspond to the circular inner muscle cells of the media, and "longitudinal fibers" which correspond to the intimal meshwork of connective tissue fibers. Regional differences are demonstrated in the occurrence of these fibres. Moreover, five morphologically different venous valve types are observed. The functional significance of these different valve types is not yet known.