Analytical Cellular Pathology - Volume 15, issue 3

Authors: Henry, Laurent | Baz, Ahsene | Château, Marie‐Thérèse | Caravano, René | Scherrer, Klaus | Bureau, Jean Paul

Article Type: Research Article

Abstract: 20S proteasomes (prosomes/multicatalytic proteinase) are protein particles built of 28 subunits in variable composition. We studied the changes in proteasome subunit composition during the differentiation of U937 cells induced by phorbol‐myristate‐acetate or retinoic acid plus 1,25‐dihydroxy‐cholecalciferol by western blot, flow cytometry and immuno‐fluorescence. p25K (C3), p27K (IOTA) and p30/33K (C2) subunits were detected in both the nucleus and cytoplasm of undifferentiated cells. Flow cytometry demonstrated a biphasic decrease in proteasome subunits detection during differentiation induced by RA+VD. PMA caused an early transient decrease in these subunits followed by a return to their control level, except for p30/33K, which remained low. …Immuno‐fluorescence also showed differences in the cytolocalization of the subunits, with a particular decrease in antigen labeling in the nucleus of RA+VD‐induced cells, and a scattering in the cytoplasm and a reorganization in the nucleus of PMA‐induced cells. Small amounts of proteasomal proteins were seen on the outer membrane of non‐induced cells; these membrane proteins disappeared when treated with RA+VD, whereas some increased on PMA‐induced cells. The differential changes in the distribution and type of proteasomes in RA+VD and PMA‐induced cells indicate that, possibly, 20S proteasomes may play a role in relation to the mechanisms of differentiation and the inducer used. Show more

Keywords: Proteasome (prosome, multicatalytic proteinase), differentiation, myeloid, leukemic, cytolocalization, western blot, flow cytometry, immunofluorescence

Citation: Analytical Cellular Pathology, vol. 15, no. 3, pp. 131-144, 1997

Authors: Ranefall, Petter | Egevad, Lars | Nordin, Bo | Bengtsson, Ewert

Article Type: Research Article

Abstract: A new method for segmenting images of immunohistochemically stained cell nuclei is presented. The aim is to distinguish between cell nuclei with a positive staining reaction and other cell nuclei, and to make it possible to quantify the reaction. First, a new supervised algorithm for creating a pixel classifier is applied to an image that is typical for the sample. The training phase of the classifier is very user friendly since only a few typical pixels for each class need to be selected. The classifier is robust in that it is non‐parametric and has a built‐in metric that adapts to …the colour space. After the training the classifier can be applied to all images from the same staining session. Then, all pixels classified as belonging to nuclei of cells are grouped into individual nuclei through a watershed segmentation and connected component labelling algorithm. This algorithm also separates touching nuclei. Finally, the nuclei are classified according to their fraction of positive pixels. Show more

Keywords: Colour image segmentation, immunohistochemical staining, pixelwise classification, relaxation, watershed segmentation, automated cell counting

Citation: Analytical Cellular Pathology, vol. 15, no. 3, pp. 145-156, 1997

Authors: Haroske, G. | Dimmer, V. | Meyer, W. | Kunze, K.D.

Article Type: Research Article

Abstract: Image cytometric DNA measurements provide data which are most often interpreted as equivalent to the chromosomal ploidy although the chromosomal and the DNA ploidy are not identical. The common link between them is the cell cycle. Therefore, if destined for DNA ploidy interpretations, the DNA cytometry should be performed on a population‐oriented stochastic basis. Using stochastic sampling the data can be interpreted by applying the rules of stochastic processes. A set of statistical methods is given that enables a DNA histogram to be interpreted objectively and without human interaction. These statistics analyse the precision and accuracy of the entire measurement …process. They give in error probabilities for accepting a measurement as reliable, for recognition of stemlines, stemline aneuploidy, and for evaluating so‐called rare events. Nearly 300 image cytometric DNA measurements from breast cancers and rat liver imprints examples have been selected to demonstrate the efficiency of the statistics in each step of interpreting DNA histograms. Show more

Keywords: DNA image cytometry, statistics, diagnostics, cancer, quality control

Citation: Analytical Cellular Pathology, vol. 15, no. 3, pp. 157-173, 1997

Authors: Razzaque, Mohammed Shawkat | Koji, Takehiko | Harada, Takashi | Taguchi, Takashi

Article Type: Research Article

Abstract: Although the role of extracellular matrices in the development of glomerulosclerosis has been discussed widely, the cellular origin of type VI collagen in diabetic nephropathy (DN) has remained relatively unexplored. This study reports the distribution and cellular origin of type VI collagen in DN. Type VI collagen‐specific oligonucleotide probes and monoclonal antibody were used to assess the relative expression of mRNA for \alpha 1 (VI) chain and its translated protein in paraffin‐embedded renal biopsy sections of DN. By immunohistochemistry, compared to the control, increased deposition of type VI collagen was noted in the diffuse and nodular lesions of diabetic …glomeruli. For cellular localization of type VI collagen mRNA, paraffin‐embedded renal sections of the control and DN were hybridized in situ with digoxigenin (Dig)‐labeled antisense oligo‐DNA probe complementary to a part of \alpha 1 (VI) mRNA. In comparison to the control kidney sections, increased numbers of intraglomerular cells (both mesangial and epithelial cells) were positive for \alpha 1 (VI) mRNA in renal biopsy sections of DN. From the results, we conclude that overexpression of type VI collagen by intraglomerular cells with its increased deposition might significantly contribute to the glomerulosclerosis found in DN. Show more

Keywords: Type VI collagen, diabetic nephropathy, immunohistochemistry, in situ hybridization

Citation: Analytical Cellular Pathology, vol. 15, no. 3, pp. 175-181, 1997