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Epithelial polarity is one example of the cell polarity that is a fundamental feature of many types of cells. Epithelial cells feature distinct 'apical', 'lateral' and 'basal' plasma membrane domains. Epithelial cells connect to one another via their lateral membranes to form epithelial sheets that line cavities and surfaces throughout the ...
Epithelial cells also exhibit planar cell polarity, in which specialized structures are orientated within the plane of the epithelial sheet. Some examples of planar cell polarity include the scales of fish being oriented in the same direction and similarly the feathers of birds, the fur of mammals, and the cuticular projections (sensory hairs ...
BerEp4 has a high sensitivity and specificity in being positive only in BCC cells. [1] BerEp4 is normally negative in squamous epithelium and mesothelium, but otherwise normally positive most epithelial cells of the body. [3] It can also help in distinguishing pulmonary adenocarcinoma (positive BerEp4) from mesothelioma (generally negative BerEp4).
By layer, epithelium is classed as either simple epithelium, only one cell thick (unilayered), or stratified epithelium having two or more cells in thickness, or multi-layered – as stratified squamous epithelium, stratified cuboidal epithelium, and stratified columnar epithelium, [8]: 94, 97 and both types of layering can be made up of any of ...
Urine typically contains epithelial cells shed from the urinary tract, and urine cytology evaluates this urinary sediment for the presence of cancerous cells [2] [3] from the lining of the urinary tract, and it is a convenient noninvasive technique for follow-up analysis of patients treated for urinary tract cancers.
Major function of cTECs is to positively select those T cells that are capable to recognize and interact with MHC molecules on their surface [3]. Once T cell precursors enter the thymic cortex, they start their transformation from double negative stages (T cell without surface expression of CD4 and CD8 co-receptors) to a double positive stage (T cell with surface expression of both co ...
Action potential in a neuron, showing depolarization, in which the cell's internal charge becomes less negative (more positive), and repolarization, where the internal charge returns to a more negative value. Most cells in higher organisms maintain an internal environment that is negatively charged relative to the cell's exterior. This ...
However the repertoire of peptides in the cortex is limited to those expressed by epithelial cells, and double positive cells are poor at undergoing negative selection. Therefore, the most important site for negative selection is the medulla, once cells are at the single positive stage.