Ultraviolet radiation (UV) induces reorganization of actin cytoskeleton in CHOAA8 cells.

Effect of UV radiation on actin cytoskeleton was studied in CHOAA8 cells by fluorescence and electron microscopy. UV irradiated cells showed impaired adherence, disruption of the actin filaments and stronger F-actin labeling in the center of the cell. Attached cells, especially enlarged ones showed rather weak labeling of stress fibers and bundles of F-actin in the cytoplasm, but some cells with intensive labeling of these structures were also observed. Detached cells were rounded, showed strong F-actin labeling and often had buds. At the ultrastructural level UV-irradiated cells showed segmented nuclei, bodies resembling micronuclei, dilatation of endoplasmic reticulum, swollen and disturb mitochondria. Immunogold labeling of actin at the ultrastructural level was observed in non-radiated and UV irradiated cells. Actin labeling was seen in nuclei and cytoplasm. In nuclei gold particles were localized in the area of condense chromatin. Labeling for actin was not found after control incubation. Our observations show that UV radiation promotes changes in the distribution of actin in CHOAA8 cells. The results also suggest that not only reorganization of actin but changes in organelles are involved in the process of apoptosis initiated by UV radiation.

Effect of doxorubicin on actin reorganization in Chinese hamster ovary cells.

Exposure of Chinese hamster ovary (CHO AA8) cells to doxorubicin in doses of 75 microM resulted in reorganization of F-actin filaments and characteristic feature of apoptosis. Even increase in size of CHOAA8 cells was observed. Attached cells become more flattered and elongated than control ones. Intense labeling of F-actin around the nucleus and disrupted filaments in cytoplasm as well as stress fibres and bundles of F-actin were seen. Cells detached were rather rounded and there were not stress fibres present. In these cells the network of F-actin was weak and rather disrupted and cells with buds labelled for F-actin were observed. In section from confocal microscopy labeling of F-actin in nucleus was confirmed. Electron microscopy showed cells with multisegmented nuclei. Cells with intracellular area with small and large vacuoles and containing also electron-dense material were seen. Other cellular organelles were rather well preserve. There were margination and condensation of chromatin in nucleus. Immunogold labelling of actin was observed in cells whether or not treated with doxorubicin. Positivity for actin was localized in the nuclei and cytoplasm. In the nucleus gold particles were localized predominantly in the area of condense chromatin. Positive labeling for actin was not found after control incubation. These findings show that doxorubicin promotes changes in the distribution of actin in CHOAA8 cells and that reorganization of actin in these cells is involved in process of apoptosis.

Relation between ultrastructural presence of CEA using peroxidase-antiperoxidase (PAP) method and tissue and serum levels of CEA in patients with breast cancer.

Ultrastructural studies were performed to detect the presence of carcinoembryonic antigen (CEA) in breast cancer by peroxidase-antiperoxidase (PAP) method. The evidenced presence of CEA was compared with the serum and tissue concentrations. A correlation between the presence of CEA at the ultrastructural level and tissue concentration was observed but not with serum levels. These studies revealed positive immunocytochemical staining for CEA when antigen concentration was 700 ng/g tissue and the reaction was strongly positive when the concentration was greater than or equal to 2000 ng/g tissue.

[Pneumocystis pneumonia in light of personal observations]. / Pneumocystozowe zapalenie pluc w swietle obserwacji wllasnych.

During a period of 10 months, 87 children with Pneumocystis carinii pneumonia accompanied transient cellular immunity disorders and with normal humoral immunity were observed. It is suggested that change the invasiveness of the parasite has changed. The necessity of taking into consideration a pneumocystis etiology in diagnosis of respiratory tract diseases among children is pointed out.