Search PubMed⌕ Search

Biomedical subjects

P Sträuli

Publications and source records attributed to P Sträuli.

At least 37 records · Page 2Linked to original sources
PubMed1982

Cell locomotion, a contributing factor in spread of the V2 rabbit carcinoma.

In histological sections of s.c. transplanted V2 rabbit carcinoma, single tumor cells and small tumor cell groups were found at some distance from the main tumor mass. This led to the question of whether locomotion could represent a contributing factor in the invasiveness of the V2 carcinoma. The behavior of V2 cells was therefore recorded under experimental conditions of increasing complexity: on glass, on the surface of a normal explanted rabbit mesentery, and on and within mesenteries of rabbit which had received intraperitoneal implants of V2 carcinoma. Time lapse cinematography showed the locomotory activity of V2 cells to be unaffected by the different substrates. In all instances the carcinoma cells migrated singly, on the two plane substrates also in small groups, under production of large leading lamellae. Intraperitoneally implanted V2 cells, in addition to their migration on the surface of the mesentery, penetrated into the interior with continuation of their characteristic translocative motility. Although cell locomotion could be established as a mechanism in the invasiveness of the V2 carcinoma, we do not consider it to be the only relevant factor. Tumor cell proliferation and destructive effects of proteinases appear to be other mechanisms contributing to the functional complex of local spread.

Animals↗
PubMed1982

Interactions between normal epithelial and squamous carcinoma cells in monolayer culture.

Confrontations of rings of adult human oral mucosa epithelial cells enclosing islands of similar normal epithelium, fibroblasts, and cells of three established lines of human squamous carcinoma in monolayer culture were investigated by phase and reflection microscopy and by time lapse cinematography. Measurements of the dimensions of the rings and islands of cells revealed that, while normal epithelial rings confronted with normal epithelium or fibroblasts migrated continuously inwards, similar rings confronting islands of the carcinomas retreated progressively outwards from the tumor islands. The persistence of substantial cell-free space between the epithelium and tumor cells indicated that the outwards migration of the epithelial rings was not solely due to proliferation of the tumor cells. The tumor-induced migration of normal epithelium in monolayer culture may reflect the response of normal epithelium to carcinoma cells in certain in vivo situations.

Carcinoma, Squamous Cell↗
PubMed1981

In vitro motility of cells from human epidermoid carcinomas. A study by phase-contrast and reflection-contrast cinematography.

The motile behavior of six cell lines derived from human squamous carcinomas (two from the larynx, four from the tongue) was studied by cinematography under phase- and reflection-contrast illumination. The recorded cell activities consist in spreading, stationary and translocation motility, and aggregate formation. Within this common pattern, quantitative modifications ("sub-pattern") are stable properties of the individual cells lines. Such modifications are particularly evident with regard to the dynamic texture of the aggregates which ranges from loose, netlike structures to compact islands with smooth borders. Accordingly, the intensity of cell traffic within and around the aggregates varies considerably. It is discussed to what extent the in vitro motility of the carcinoma cell populations reflects their behavior in the organism and thus the significance of cell movements for invasion.

Carcinoma, Squamous Cell↗
PubMed1981

Different modes of mesenteric infiltration displayed by two rat leukemias. A study by scanning and transmission electron microscopy and by microcinematography.

Infiltration of the mesentery after intraperitoneal implantation of two transplantable rat leukemias, the undifferentiated L5222 and the myeloid BNML, was studied by means of scanning and transmission electron microscopy, and microcinematography. In animals implanted with L5222 cells, contraction of the mesenteric mesothelium is a conspicuous feature. It occurs within the first 24h after implantation and influences decisively the course of infiltration. In contrast, The presence of BNML cells leads to mesothelial contraction only in the terminal stage and, therefore, exerts no direct effect on infiltration. In addition, the two leukemias differ with regard to their cellular motility. Whereas L5222 cells locomote within the mesentery, only stationary movements are recorded with BNML cells. Based on the different interactions with the mesothelium and cell motilities, two distinct modes of infiltrating the mesentery could be ascertained for the two rat leukemias.

Animals↗
PubMed1981

Histochemical localization of cathepsin B at the invasion front of the rabbit V2 carcinoma.

To clarify the role of cathepsin B in tumor invasion, the enzyme was visualized in tissue frozen sections of the subcutaneously growing rabbit V2 carcinoma. Localization of cathepsin B was achieved by immunofluorescent staining and by enzyme histochemistry. For the former approach, a sheep antiserum was raised against purified cathepsin B from rabbit liver. The antibodies, isolated by immunoadsorption, reacted monospecifically with rabbit liver cathepsin B in Ouchterlony double diffusion and in immunoelectrophoresis. In the enzyme histochemical assay, Z-Ala-Arg-Arg-methoxynaphtylamide was used as fluorogenic substrate and nitrosalicylaldehyde as coupling agent. With both methods, cathepsin B was found to be localized within fibroblasts and leukocytes assembled at the tumor invasion front. In addition, immunofluorescent staining demonstrated the occurrence of the enzyme in the extracellular matrix surrounding tumor cell clusters. Carcinoma cells always remained unstained. The conclusion is drawn that cathepsin B is chiefly produced by host cells which are stimulated to increase synthesis and to release the enzyme under the influence of the tumor. A dual function can be ascribed to cathepsin B concentrated in the vicinity of the tumor: it operates intracellularly (in host cells) through degradation of endocytosed protein and extracellularly through activation of collagenase. The resulting lytic action on host structures appears to be a prerequisite for local spread of the V2 carcinoma.

Animals↗
PubMed1979

Lymphocytes, but not cancer cells are able to penetrate into the rat embryo yolk sac wall.

Normal rat lymphocytes and cells of 2 highly invasive tumors, the L5222 rat leukemia and the VW rabbit carcinoma, were inoculated in vitro on the mesothelial surface of the visceral wall of the rat embryo yolk sac. After 48 h, lymphocytes, without any damage being inflicted on the mesothelial cells, had penetrated deeply into the yolk sac wall, whereas both kinds of cancer cells had destroyed the mesothelial cells, but not advanced beyond the basal lamina.

Animals↗
PubMed1979

The fluorescence and bright field microscopic demonstration of cathepsin B in human fibroblasts.

Cathepsin B was demonstrated cytochemically in human fibroblasts with Z-Ala-Arg-Arg-2-(4-methoxy)naphtylamide as substrate. The enzyme was visualized in the bright field microscope with the diazonium salt Fast Blue B as coupling reagent and in the fluorescence microscope with 5-nitrosalicylaldehyde. With both methods cathepsin B was found in small granules distributed throughout the cytoplasm.

Carcinoma, Squamous Cell↗
PubMed1979

Dynamic morphology applied to human and animal leukemia cells.

Dynamic morphology, which describes the shape and surface architecture of fixed cells in terms related to their behavior in the living state, is based on the concurrent use of two methods: scanning electron microscopy and microcinematography. This combination has both advantages and disadvantages. In this study on leukemic cells, we were able to draw the following conclusions about the usefulness of dynamic morphology. It confirms that white blood cells do not flatten on a glass substrate; they stay spherical and are either round or polarized. Round cells of similar size, whatever their origin, cannot be classified by dynamic morphology. Polarized cells can be classified as blasts, promyelocytes, myelocytes, granulocytes and lymphocytes, although polarized blast cells of different origins cannot be differentiated. Dynamic morphology cannot classify the same cell type as benign or malignant.

Animals↗
PubMed1978

Intermediate-sized filaments in leukemia cells.

Electron microscopic studies on human acute leukemias have shown that leukemic populations contain spherical and polarized cells in various proportions. As recorded by time-lapse cinematography, the two cell configurations represent different functional states: resting cells are completely spherical, locomotive cells are polarized with a conspicuous extension posteriorly. In 9 out of 12 cases of acute myeloid leukemia the two cell configurations were found to coincide with a different pattern of intermediate-sized filaments (ISF). Most spherical myeloblasts possessed large bundles of ISF (a minority had small bundles), whereas polarized myeloblasts showed small groups or single filaments. A similar correlation between cell shape and arrangement of ISF was observed in a transplantable undifferentiated rat leukemia. Two concepts can be distinguished with regard to the role of fibrillar structures in leukemic myeloblasts: thick bundles of ISF either represent a pathological state or have a functional significance. A tentative interpretation of our own results provides some arguments in favor of a disaggregation-reaggregation cycle of thick ISF bundles, whereas a pathological ("end stage") nature of these structures appears less likely.

Acute Disease↗
PubMed1977

Motility of L 5222 rat leukemia cells in the flattened state. Evidence against emperipolesis.

Emperipolesis is the term for the assumed penetration of living cells into other living cells. As reported earlier, L 5222 rat leukemia cells, migrating in vitro, change from a spherical to a spread configuration when they meet flat cells, and continue to move in this shape within the contours of the target cells. Whether or not this close cellular association corresponded to emperipolesis could not be determined with phase and interference contrast cinemicrography alone. In combination with transmission electron microscopy, it could be demonstrated that the compartment, in which the spread leukemia cells move, is not the cytoplasm of the target cells, but the narrow space created by the target cells and the underlying glass surface. Thus, emperipolesis could be ruled out for L 5222 leukemia cells. On this basis the reported observations on emperipolesis are reviewed, and a critical attitude regarding the occurrence of emperiopolesis in general is advocated.

Animals↗