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Difference between revisions of "Course:Introduction to Neuropathology"
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Course:Introduction to Neuropathology (view source)
Revision as of 14:25, 30 September 2015
, 14:25, 30 September 2015→Molecular neuropathology: Source: https://en.wikipedia.org/wiki/Ki-67_%28protein%29
Jensflorian (talk | contribs) (→Molecular neuropathology: pathology workflow) |
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* standardisation (the same staining conditions are applied). | * standardisation (the same staining conditions are applied). | ||
* sample number (high statistical power for associations). | * sample number (high statistical power for associations). | ||
====Neuropathology basics==== | |||
This section deals with normal cellular constituents of the CNS. | |||
[[File:Blausen 0870 TypesofNeuroglia.png |500px|left| Types of neuroglia (WC/Blausen)]] | |||
<gallery> | |||
File:Astrocytes.jpg | Astrocytes highlighted by GFAP. | |||
Image:Oligodendrocyte_HE_stain_high_mag.jpg | Oligodendrocytes. | |||
Image:Ependyma.png|Ependymal cells. (WC/marvin101) | |||
File:Psammoma bodies in the choroid plexus, HE.JPG | Choroid plexus. | |||
File:Mikroglej 1.jpg | Activated microglial cells, Lectin stain. | |||
</gallery> | |||
Neurons are often very large cells, with angled edges and abundant cytoplasm that contains Nissl substance (granular perinuclear material = rough endoplasmic reticulum). The round nucleus of larger cells has weak chromatin and a prominent nucleolus. Some neurons such as the granular layer in the [[cerebellum]] are | |||
quite small instead. There are several types of glial cells. Oligodendrocytes have a small round, centrally located nucleus (lymphocyte-like). The cytoplasm is often glassy. Astrocytes have am irregular non-ovoid nucleus. They are often close to blood vessels where the form the blood-brain barrier. Their stellate cytoplasmic processes are normally not visible in normal neuropil backgeound. Ependymal cells are a simple ciliated cuboidal epithelium psitioned at the surface of the ventricles and central canal. Cells of the choroid plexus. are specialized ependymal cells surrounding a core of capillaries and loose connective tissue and are located within the ventricels where they produce the cerebrospinal fluid. Microglia are the immune-competent cells of the brain (macrophages). They often have vesicles and are rarely seen in normal tissue | |||
===Day 2=== | |||
The exact classification of brain tumours is essential for proper treatment of patients. Although morphological evalutaion of the [[H&E]] stained tumour specimen is a crucial first step, subsequent immunhistochemical stains and molecular analyses help to secure the diagnosis. The following five antibodies: GFAP, [[MAP2]], [[ATRX]], [[IDH-1]], pan-Cytokeratin and Ki-67 (MiB-1) allow for good classification of the most common tumours observed in the brain. A short introduction: | |||
* Ki-67 (Kiel-67, clone MiB-1 which stands for Made in Borstel) is a nuclear protein that is associated with cellular proliferation. During interphase, the Ki-67 antigen can be exclusively detected within the cell nucleus, whereas in mitosis most of the protein is relocated to the surface of the chromosomes. Ki-67 protein is present during all active phases of the cell cycle (G1, S, G2, and mitosis), but is absent from resting cells (G0).<ref name="pmid10653597">{{Cite journal | last1 = Scholzen | first1 = T. | last2 = Gerdes | first2 = J. | title = The Ki-67 protein: from the known and the unknown. | journal = J Cell Physiol | volume = 182 | issue = 3 | pages = 311-22 | month = Mar | year = 2000 | doi = 10.1002/(SICI)1097-4652(200003)182:3<311::AID-JCP1>3.0.CO;2-9 | PMID = 10653597 }}</ref> Ki-67 is an excellent marker to determine the growth fraction of a given cell population. The fraction of Ki-67-positive tumor cells (the Ki-67 labeling index) is often correlated with the clinical course of cancer. <ref>https://en.wikipedia.org/wiki/Ki-67_%28protein%29</ref> An [[astrocytoma]] with 2% positive tumor cells is growing considerably slower than a [[glioblastoma]] with a labelling index of 20%. Cells with a quick turnover therefore serve as good positive controls for this antibody. | |||
* | |||
A descriptive overview of various brain tumours is found [[Neuropathology tumours|here]]. | |||
==References== | ==References== | ||