What's the difference between hair and keratin?

Hair


Definition:

  • (n.) The collection or mass of filaments growing from the skin of an animal, and forming a covering for a part of the head or for any part or the whole of the body.
  • (n.) One the above-mentioned filaments, consisting, in invertebrate animals, of a long, tubular part which is free and flexible, and a bulbous root imbedded in the skin.
  • (n.) Hair (human or animal) used for various purposes; as, hair for stuffing cushions.
  • (n.) A slender outgrowth from the chitinous cuticle of insects, spiders, crustaceans, and other invertebrates. Such hairs are totally unlike those of vertebrates in structure, composition, and mode of growth.
  • (n.) An outgrowth of the epidermis, consisting of one or of several cells, whether pointed, hooked, knobbed, or stellated. Internal hairs occur in the flower stalk of the yellow frog lily (Nuphar).
  • (n.) A spring device used in a hair-trigger firearm.
  • (n.) A haircloth.
  • (n.) Any very small distance, or degree; a hairbreadth.

Example Sentences:

  • (1) Cook, who has postbox-red hair and a painful-looking piercing in his lower lip, was now on stage in discussion with four fellow YouTubers, all in their early 20s.
  • (2) The surface of all cells was covered by a fuzzy coat consisting of fine hairs or bristles.
  • (3) We have isolated a murine cDNA clone, pCAL-F559, for the calcium-binding protein calcyclin by differential screening of a cDNA library made from RNA isolated from hair follicles of 6-d-old mice.
  • (4) White hair bulbs which demonstrated no TH activity formed 2SCD, but not 5SCD.
  • (5) Isolated outer hair cells from the organ of Corti of the guinea pig have been shown to change length in response to a mechanical stimulus in the form of a tone burst at a fixed frequency of 200 Hz (Canlon et al., 1988).
  • (6) We have reported on a simple and secure method of tying up hair during transplantation surgery for alopecia.
  • (7) Bone age has been analyzed mixed-longitudinally in a subsample of 370 patients (660 observations) and showed a slight retardation at all ages between 6 and 13 yr. Development of pubic hair of 91 subjects analyzed cross-sectionally was definitely retarded when compared to adequate reference data.
  • (8) Tumors were induced in athymic, T-cell-deficient nude mice and in syngeneic normal haired mice by treatment with low doses of 3-methylcholantrene (MCA).
  • (9) As I looked further, I saw that there was blood and hair and what looked like brain tissue intermingled with that to the right area of her skull."
  • (10) A new method of staining the keratin filament matrix allowing a visualization of the filaments in cross section of hair fibres has been developed.
  • (11) However, in subjects with alopecia there was no such difference and the growth rate of all the hairs showed a continuous distribution.
  • (12) No infection threads were found to penetrate either root hairs or the nodule cells.
  • (13) After 7 days, various stages of sensory hair degeneration could be observed.
  • (14) This review of androgenetic alopecia (AA) in women provides a summary of hair physiology and biochemistry, a general discussion of AA, and a brief description of other types of hair loss in women.
  • (15) Subungual hair penetration appears to be much less common.
  • (16) Steep longitudinal and transverse gradients of glycogen are known to exist in the organ of Corti of the guinea pig, with preferential accumulation in the outer hair cells of the apical turns.
  • (17) Of four normal tissues assessed, two (hair follicles and tissues responsible for development of leg contractures) showed no change in radioresponse after treatment with indomethacin, one (hematopoietic tissue) exhibited radioprotection, and one (jejunum) exhibited slight radiosensitization (enhancement factor, 1.12).
  • (18) On the other hand, the total number of missing hair cells, irrespective of location, was a good, general indicator of the hearing capacity in a given ear.
  • (19) The objective was to determine whether the parent axonal impulse train elicited by dual-hair stimulation was due to a temporal combining ("mixing"; Fukami, 1980) of the impulse trains elicited in the parent axons by the same stimulation to each hair alone.
  • (20) In addition to descriptions of variants of the root appearance for hairs removed from follicles in the three classical growth phases, several other commonly occurring root configurations are described and illustrated with photomicrographs.

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.