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Components of Nutrition
Published in Christopher Cumo, Ancestral Diets and Nutrition, 2020
Proteins perform crucial functions. For example, insulin, mentioned earlier and having fifty-one amino acids, is the hormone that tells cells to admit glucose.69 In this way, insulin regulates the amounts of glucose inside and outside cells. Insulin also regulates glucose by telling the liver to store excess for release when the sugar becomes scarce in blood. Heme proteins, defined by the presence of iron (Fe), shuttle molecules and electrons throughout the body. Hemoglobin, a component of red blood cells, brings oxygen to cells and removes carbon dioxide for transport to the lungs. Carbon dioxide is a greenhouse gas, though human respiration emits little compared to factories and automobiles. The protein keratin helps form hair and skin. Proteins known as enzymes catalyze the body’s reactions. For example, enzymes pepsin and trypsin aid protein digestion by catalyzing cleavage of amino acid peptide bonds, mentioned earlier. Integral to the immune system, proteins that combat pathogens are known as antibodies. Attention has focused on the protein interferon, which targets viruses.
Polymer Materials for Oral and Craniofacial Tissue Engineering
Published in Vincenzo Guarino, Marco Antonio Alvarez-Pérez, Current Advances in Oral and Craniofacial Tissue Engineering, 2020
Iriczalli Cruz Maya, Vincenzo Guarino
Keratin is a fibrous protein, found in hair, wool, feathers, nails and horns of mammals, reptiles and birds. Keratin proteins can be classified in intermediate filament proteins and the matrix proteins. The characteristic secondary structure of intermediate filaments is a-helix, also known as α-keratins and are low in sulfur content. The matrix proteins are globular, have high sulfur content and are surrounding the intermediate filament proteins interacting through disulfide bonds (Magin et al. 2007). Keratin is characterized by the presence of sequences as RGD (Arg-Gly-Asp) and LDV (Leu-Asp-Val) found in several ECM proteins for cell adhesion. Thus, keratin has been proposed as an alternative to collagen for developing biomaterials for tissue regeneration (Srinivasan et al. 2010). Besides, several studies have shown that the addition of keratin and adjusting its concentration, improved the mechanical properties of biomaterials (Zhang et al. 2014; Wang et al. 2015).
The Naked (N) Mutation, Chromosome 15
Published in John P. Sundberg, Handbook of Mouse Mutations with Skin and Hair Abnormalities, 2020
The naked mouse mutation was considered to resemble the dominantly inherited human disease known as hydrotic ectodermal dysplasia,16 but the amino acid changes in the hairs are different between the two species.13 The human disease is believed to be caused by loss of a hair follicle matrix component.17 Human patients have normal sweat and sebaceous gland function, total alopecia, severe dystrophy of nails, hyperpigmentation of skin (particularly over joints), normal teeth, strabismus, mental deficiency, clubbing of fingers, and palmer hyperkeratosis (variable).18 The human disease may be due to a molecular abnormality of keratins.17 Human hair is thin with reduced tensile strength, disorganized fibrillar structure, reduced birefringence, and increased amounts of reactive sulfhidryl groups.19,20
Optimal diagnosis and management of common nail disorders
Published in Annals of Medicine, 2022
Clinically, there are three types of nail fragility: lamellar onychoschizia, onychorrhexis and superficial granulation of keratin. Lamellar onychoschizia, also known as lamellar dystrophy, is characterized by the presence of fine horizontal layers that crack and peel easily from the free margin (Figure 1(A)). Impaired intercellular adhesion of the nail plate is thought to contribute to this condition [2,3,6]. This form of nail fragility is common in patients who wash their hands excessively (e.g. healthcare workers and homemakers) and those with lichen planus [3,5]. Onychorrhexis is defined as longitudinal splitting and fissuring of the superficial nail plate (Figure 1(B)). It is often seen among the elderly and in conjunction with onychoschizia. Its clinical presentation depends on the severity and degree of involvement of the nail matrix. It may result from an isolated split at the free edge of the nail plate that extends proximally [3]. Superficial granulation of keratin presents in the distal nail plate. It is characterized by white-yellow discolouration and striations. The keratins in the nail plate undergo an exfoliative process resulting in formation of patches. This condition is most commonly reported in patients who wear nail varnish often [3,5].
Long-lasting treatment for moderate-severe depressed facial scars: skin and hair derived new autologous tissue filler with subcision
Published in Journal of Dermatological Treatment, 2022
Qi Chen, Yue Yang, Jiao Zhang, Qingguo Zhang
Keratin was collected from autologous hairs. Generally, 3–5 g of hair was obtained from volunteers and processed according to our previous study (10). After being disinfected with ethanol and washed by sterile PBS solution for repeatedly 3 times, hairs mass was cut into small pieces and rinsed with detergent solution, and dried after degreasing. Then, the dried hair was soaked in solution A (30 parts 0.5% H2SO4 with 1 part 0.32% NaClO) for 20 min at 20 °C for chloridizing. It was then rinsed with sterile PBS for 3 times. Next, the hair was immersed in solution B (30% H2O2, sodium pyrophosphate (8 g/L), potassium persulfate (3 g/L), and aqueous ammonia (14 g/L)) for 3.5 h at 40 °C water bath until the color whitened, and then rinsed for 3 times to remove the remaining chemicals, then bleached hair piece was dried at 30 °C. Planetary high-energy ball mill (QM-ISP4) and a plurality of planetary mill nylon pots were used for producing hair particles. Discolored hairs were mixed with distilled water (7:1 v/w) and added to a planetary mill nylon pots. The hair particle size was controlled by the predetermined period of time. This step was setup at 8 h to get the desirable particle size (the mean diameter is about 80um). The particles were sterilized by radiation sterilization using 60 Co-radiation (25 kGy). All the products can be lyophilized and stored at 4 °C for future use (Patent No: CN101530636, Qingguo Zhang).
Berberine modulates Keratin 17 to inhibit cervical cancer cell viability and metastasis
Published in Journal of Receptors and Signal Transduction, 2021
Luping Liu, Li Sun, Jing Zheng, Li Cui
Keratin (KRT) is a protein family that is critical for hair formation and is the essential cellular structural material in forming the cornified layer which protects cells against damage or physical stress [10]. Keratin 17 (KRT17) is a kind of type I KRT [10], and upregulation of KRT17 expression is associated with lesion progression as well as poor prognosis in a number of epithelial cancers [11]. For example, overexpression of KRT17 was related to poor prognosis in epithelial ovarian cancer [12]. KRT17 performs an immunomodulatory function in skin by polarizing the immune response through up-regulating epithelial proliferation and tumor growth [13]. In addition, it is worth noting that an up-regulated KRT17 expression level was found in advanced cervical cancer tissue, and is closely associated with the poor survival of patients with this disease [14]. However, whether KRT17 could be regulated by BBR in cervical cancer cells remains elusive.