What's the difference between keratin and rhamphotheca?
Keratin
Definition:
(n.) A nitrogenous substance, or mixture of substances, containing sulphur in a loose state of combination, and forming the chemical basis of epidermal tissues, such as horn, hair, feathers, and the like. It is an insoluble substance, and, unlike elastin, is not dissolved even by gastric or pancreatic juice. By decomposition with sulphuric acid it yields leucin and tyrosin, as does albumin. Called also epidermose.
Example Sentences:
(1) The observed staining indicated that the epithelium of the external auditory meatus has a pattern of keratin expression typical of epidermis in general and the epithelium of the middle ear resembles simple columnar epithelia.
(2) A new method of staining the keratin filament matrix allowing a visualization of the filaments in cross section of hair fibres has been developed.
(3) The positive reaction for keratin and vimentin confirmed the presence of ectodermal and mesodermal elements respectively in the tumor.
(4) The mean gain in width of keratinized gingiva averaged 3.15 mm.
(5) The histological changes by light and electron microscopy in these patients demonstrates the metaplastic changes of the basal cell of the mucosa differentiating into mucous and keratin cells.
(6) These particular keratins that were found among others in basal cells could also be detected to a variable extent in metaplastic and dysplastic cervical lesions.
(7) Chemically isolated separate preparations of the non-aggregating protein-chondroitin-keratin sulphate (PCKS) fraction from the hyaline cartilage and hyaluronic acid (HUA) of the vitreous body and of the umbilicus were investigated by electron microscopy.
(8) In benign lesions both keratins were present, while in malignant ones only keratin No.
(9) The diagnosis was defined by immunohistochemical methods, which showed a positivity for keratin in the cells lining spaces with a vascular appearance.
(10) All of the cell lines expressed keratin intermediate filaments and two showed weak co-expression of vimentin.
(11) The expression of keratin and differentiation markers was identical to that of normal keratinocytes, suggesting that psoriatic epidermal differentiation is not truncated in vitro as has been postulated to be the case in vivo.
(12) In seven out of eight patients, the urothelium adjacent to the squamous cell metaplasia was also positive for keratin, indicating a direct transformation of the urothelium to squamous cell epithelium.
(13) Carcinomas fail to express suprabasal cell keratins and this is regulated at the transcriptional level.
(14) Lactobacillus strains of numerous species isolated from several animal sources exhibited cellular hydrophobicities that differed from those expected on the basis of their abilities to colonize the keratinizing stratified squamous epithelium in the mouse stomach.
(15) Furthermore the presence of keratin 17 in a CIN I, II, or III lesion may indicate progressive potential while its absence could be indicative of a regressive behavior.
(16) We did not observe two distinct types of cells with different morphology or components which could be held responsible for the production of two different types of keratin as have been described in other animals, but rather a uniformity of cell structures in each layer and only the so-called "smooth" type of keratin.
(17) The present study compares different post-embedding staining methods, including conventional and low-temperature embedding techniques, for demonstration of the keratin and vimentin cytoskeleton of epidermal cells, applying commercially available polyclonal and monoclonal antibodies.
(18) All cases so examined had positive results for vimentin and negative results for keratin.
(19) We have examined the keratin proteins in normal human oral mucosa from 6 different regions including hard palate, buccal mucosa, tongue, gingiva and floor of the mouth.
(20) Expression of keratins of high molecular weight was reduced to small foci of keratinization and scattered dyskeratotic cells.