Expression of calretinin in human mesothelioma cell lines and cell cycle analysis by flow cytometry.

Human mesothelioma cell lines were studied concerning the expression of the calcium-binding protein calretinin (CR), and the relation of the DNA index to their cell cycle. The results obtained for cell lines with different morphological characteristics, were compared to those from human mesothelial cells transfected with SV40 to escape senescence. Immunocytochemical expression of calretinin (confirmed by immunoblot) was observed in all mesothelioma cell lines but not in the control cells. It is suggested that calretinin is active in the first steps of carcinogenesis in all human mesotheliomas and during several stages in the evolution towards malignancy.

Comparative studies of calretinin expression by WiDr cell line in vivo in xenografts in nude mice and in vitro.

WiDr cells from a human colon adenocarcinoma cultivated in vitro express the calcium binding protein calretinin. The immunoreactivity is present in some interphasic cells and decreases after seven days in culture together with the augmentation of the cell number. Calretinin expression is maintained in the undifferentiated cells of the tumoral mass developed in nude mice and in recultivated isolated tumour cells from the xenograft. From the experiments here described, the protein expression is quantitatively influenced in vitro by the addition of drugs, such as colchicine and taxol, which intervene in cytoskeleton organisation. The percentage of the calretinin immunoreactive cells increases after the addition of colchicine to the medium while the immunoblot analysis shows a higher calretinin content in the cells treated with taxol.

Morphological aspects of lymphocyte-macrophage interactions in human tumoral effusions "in vivo" and "in vitro".

"In vivo" and "in vitro" morphological analysis of associations of cells ("rosettes") involved in immune response in human tumoral effusions revealed the existence of cell interactions either by simple membrane apposition between the cell projections or by gap-like junctions between two adjacent cells; endocytotic phenomena were also observed. The giant fibroblastic cells seen "in vitro" ("myofibronoblasts") reacting positively to anti-human macrophage Mabs, might be the cells presenting antigen to lymphocytes.

Microcinematographic and electron microscopic study of the death of human tumor cells induced by histiocytic cells.

The cells from a malignant fibrous histiocytoma were enzymatically isolated and cultured in vitro. The cultures were observed by microcinematography and with an electron microscope after fixation and embedding. The interactions between histiocytic and tumor cells resulted in tumor cell death. The microcinematographic study revealed that filiform projections of the histiocytic cell protrude toward the tumor cell surface making contacts for varying periods of time. The tumor cell then contracts and almost simultaneously some granules (lysosomes?) appear in the tumor cell cytoplasm. These granules eventually fuse with each other thus increasing in volume. The resulting granulation heads for the periphery of the tumor cell at a site previously touch by a projection of a histiocytic cell; at this site the membrane bursts and the tumor cell dies leaking amorphous cytoplasmic material. Before bursting the tumor cell does not show any noticeable morphological changes.

[Cells affected by apoptosis in effusions of tumor origin in man]. / Cellules affectées par l'apoptose dans des épanchements d'origine tumorale chez l'homme.

The cells from 3 human effusions of tumoral origin (adenocarcinoma) were observed by light and transmission electron microscopy. The presence and the type of cells undergoing apoptosis were studied. Among the different cell types present in these effusions, only some lymphocytes, macrophages and eosinophils (cells concerned in cell-mediated tumor immunity) are affected by the morphological changes of apoptosis. We did not find, as other authors did, tumor cells or other cell types (mesothelial cells, histiocytes, other granulocytes) showing apoptic alterations. The authors conclude that this peculiar morphological type of cell death affects the effector cells of the cell-mediated tumor immunity being at the end of their life-span.

[Analysis of the structure and distribution of chromatin in interphase nuclei of different cell types from a pleural effusion of tumoral origin in man. Cytophotometric and electron microscopic studies]. / Analyse de la structure et de la distribution de la chromatine des noyaux en interphase des différents types cellulaires se trouvant dans un épanchement pleural humain d'origine tumorale. Etude par cytophotométrie et microscopie électronique.

The authors have studied the distribution and the structure of the chromatin in the different cell types from a human pleural effusion of tumoral origin (mammary adenocarcinoma). The results show that in the entire nuclei the distribution and the structure of the chromatin cannot be considered as characteristic morphological features of the cells of the same cellular type. Thus making a clear distinction among differentiating cells and cells in DNA synthesis or in G2 period, only based on these properties of the chromatin, is very debatable. On the other hand, the distribution and the structure of the chromatin permit to characterize the different cell types in G1 period. The authors discuss the possible differential cytological diagnosis of the smears from human effusions of tumoral origin.

Peculiar ultrastructural features in the cytoplasm of cells from human effusions associated with malignant disease.

A peculiar structure revealed by the electron microscope in a few cells from two human pleural fluids, showing the morphologic features of metastasizing cancer cells in effusions, is described. It has the appearance of a rod-shaped pentalaminary structure approximately 25-35 nm thick formed by an outer double membrane, surrounding a central, more dense axis showing transverse striations at about 10-nm intervals. The double membrane often exhibits a terminal expansion connected with the endoplasmic reticulum and it is sometimes associated with microfilaments. These structures could be a variant of or represent a step in the formation of confronting cisternae, but the periodic striations they show in the more dense lamella give them some resemblance to a Langerhan's cell granule. To date, such striations have not been seen in confronting cisternae.

In vitro responses of proliferating and non-proliferating cells to high doses of 17 beta-estradiol: cytochemical study.

The authors studied the effect of 17 beta-estradiol on the proliferation in vitro of chick embryo fibroblasts and human macrophages by microdensitometry, cytofluorometry, and autoradiography. For fibroblasts 17 beta-estradiol shortens the duration of the preparing period to mitosis, particularly of the synthetic phase (S) and has no effect on the duration of mitosis. For macrophages, which have temporarily lost their mitotic capacity, 17 beta-estradiol cannot induce mitotic division.

A quantitative microdensitometric and autoradiographic study of the effect of 4'-demethyl-epipodophyllotoxin-beta-D-thenylidene glucoside (VM-26) on the cell cycle of cultured fibroblasts.

The effect of 4'-demethyl-epipodophyllotoxin-beta-D-thenylidene glucoside (VM-26) , a semi-synthetic derivative of podophyllotoxin, on the cell cycle was studied with chick embryo fibroblasts cultivated in vitro. DNA, RNA and protein content, as well as NADH-diaphorase activity were determined by quantitative microdensitometry and cytofluorometry. The incorporation of [3H]thymidine and [3H]leucine into DNA and proteins were analysed by autoradiography. These metabolic data correlated with morphological observation showed that VM-26 blocks the cell cycle at different moments of its kinetics depending on both the dose and the time exposure. NADH-diaphorase activity is the first to be affected, then biochemical changes (involving the metabolism of RNA and proteins) and morphological alterations (especially of mitochondria) follow. This suggests that VM-26 may act primarily upon the mechanism of respiration of the cell.

[Carbohydrate metabolism in the bovine carotid artery contracted by the action of potassium chloride]. / Sur le métabolisme des hydrates de carbone de l'artère carotide de bovidé contractée sous l'action du chlorure de potassium

The concentration of some end products and the activity of some enzymes participating in carbohydrates metabolism were examined in bovine carotid artery contracted by KCl. Oxygen consumption decreased significantly, anaerobic glycolysis and tissue lactic acid content increased during the KCl contraction. The hexosamines and the uronic acids producing ability of the KCl contracted artery were also higher. During contraction the SDH activity decreased in a smaller degree, cytochrome oxydase activity in a much more important degree. On the basis of our results we can conclude that the complete oxydation pathway of carbohydrates degradation, as mucopolysaccharides synthesis and degradation have an important part in the energy metabolism, but anaerobic glycolysis is the most important pathway to produce energy for the KCl contraction of vascular smooth muscle.