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Gandolfi B, Outerbridge CA, Beresford LG, Myers JA, Pimentel M, Alhaddad H, Grahn JC, Grahn RA, Lyons LA. The naked truth: Sphynx and Devon Rex cat breed mutations in KRT71. Mamm Genome 2010; 21:509-15. [PMID: 20953787 PMCID: PMC2974189 DOI: 10.1007/s00335-010-9290-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Accepted: 09/13/2010] [Indexed: 01/25/2023]
Abstract
Hair is a unique structure, characteristic of mammals, controlling body homeostasis, as well as cell and tissue integration. Previous studies in dog, mouse, and rat have identified polymorphisms in Keratin 71 (KRT71) as responsible for the curly/wavy phenotypes. The coding sequence and the 3′ UTR of KRT71 were directly sequenced in randomly bred and pedigreed domestic cats with different pelage mutations, including hairless varieties. A SNP altering a splice site was identified in the Sphynx breed and suggested to be the hairless (hr) allele, and a complex sequence alteration, also causing a splice variation, was identified in the Devon Rex breed and suggested to be the curly (re) allele. The polymorphisms were genotyped in approximately 200 cats. All the Devon Rex were homozygous for the complex alterations and most of the Sphynx were either homozygous for the hr allele or compound heterozygotes with the Devon-associated re allele, suggesting that the phenotypes are a result of the identified SNPs. Two Sphynx carrying the proposed hr mutation did not carry the Devon-associated alteration. No other causative mutations for eight different rexoid and hairless cat phenotypes were identified. The allelic series KRT71+ > KRT71hr > KRT71re is suggested.
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102
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Sgrò CM, Wegener B, Hoffmann AA. A naturally occurring variant of Hsp90 that is associated with decanalization. Proc Biol Sci 2010; 277:2049-57. [PMID: 20200026 PMCID: PMC2880099 DOI: 10.1098/rspb.2010.0008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2010] [Accepted: 02/12/2010] [Indexed: 11/12/2022] Open
Abstract
The heat shock protein Hsp90 has been the focus of many studies since it was suggested that it acts to mediate the buffering of phenotypic variation. Hsp90-mediated buffering may result in the accumulation of cryptic genetic variation that, when released either as a consequence of environmental or genetic stress, increases the evolvability of a population. Recent studies using laboratory-induced mutations of Hsp90 and/or chemical inhibition to disrupt Hsp90 function confirm that Hsp90 can buffer cryptic genetic variation. We have previously identified a naturally occurring variant in the charged linker region of the Hsp90 gene, and now examine whether this variant is associated with altered levels of trait variability. The variant is associated with the release of cryptic genetic variation for canalized morphological (bristle) traits, but not for uncanalized morphological (wing and bristle) traits, and the effect on canalized traits depends on culture temperature. This suggests that natural genetic variation in Hsp90 may mediate the evolution of canalized morphological traits even if it does not influence the expression of variation for uncanalized traits.
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103
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104
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Drewa T, Joachimiak R, Kaznica A, Sarafian V, Pokrywczynska M. Hair stem cells for bladder regeneration in rats: preliminary results. Transplant Proc 2010; 41:4345-51. [PMID: 20005396 DOI: 10.1016/j.transproceed.2009.08.059] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Revised: 06/28/2009] [Accepted: 08/17/2009] [Indexed: 01/27/2023]
Abstract
BACKGROUND A variety of tissue engineering techniques are currently under development or investigation for bladder augmentation, but so far no approach is clearly superior. The aim of this study was to compare the suitability for cystoplasty augmentation in rats of in vivo implanted acellular bladder matrices (BAM) previously seeded with hair follicle stem cells and that of matrices implanted without the cells. MATERIALS AND METHODS The rat hair follicle stem cell line was positive for CD34, p63, and Ki-67. 1 x 10(6) cells from 34 to 40 passages seeded onto nine BAM scaffolds were cultured for one week. Nine other scaffolds were left unseeded. Scaffolds were grafted into a surgically created defect within the anterior bladder wall: nine rats with acellular matrices and nine with cell-seeded BAM. Rats observed for six months were killed in monthly intervals. We performed gross examination, X-ray cystography, and hematoxylin-eosin, cytokine (CK)-7, CK-20, myoglobin, and desmin staining of the excised bladders. RESULTS Minimal adhesions were observed and urinary leakage was noted in one case. Two animals died in the acellular group. Rats developed stone disease in bladders reconstructed with acellular BAM. Bladder capacity was similar, but the shape was regular and characteristically oval only in bladders grafted with cell-seeded BAM. Muscle layers in the apical parts of the reconstructed bladder walls were extremely thin in the cases of acellular grafts and thicker in bladders reconstructed with cell-seeded grafts. Muscle layer regeneration was better in the cell-seeded group. Urothelium regenerated in all animals. CONCLUSIONS We have shown that hair follicle stem cells may be used for rat bladder wall regeneration.
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105
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Lewin GC, Hallam J. A computational fluid dynamics model of viscous coupling of hairs. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2010; 196:385-95. [PMID: 20383713 DOI: 10.1007/s00359-010-0524-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 03/11/2010] [Accepted: 03/18/2010] [Indexed: 11/26/2022]
Abstract
Arrays of arthropod filiform hairs form highly sensitive mechanoreceptor systems capable of detecting minute air disturbances, and it is unclear to what extent individual hairs interact with one another within sensor arrays. We present a computational fluid dynamics model for one or more hairs, coupled to a rigid-body dynamics model, for simulating both biological (e.g., a cricket cercal hair) and artificial MEMS-based systems. The model is used to investigate hair-hair interaction between pairs of hairs and quantify the extent of so-called viscous coupling. The results show that the extent to which hairs are coupled depends on the mounting properties of the hairs and the frequency at which they are driven. In particular, it is shown that for equal length hairs, viscous coupling is suppressed when they are driven near the natural frequency of the undamped system and the damping coefficient at the base is small. Further, for certain configurations, the motion of a hair can be enhanced by the presence of nearby hairs. The usefulness of the model in designing artificial systems is discussed.
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106
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Wortmann FJ, Stapels M, Chandra L. Modeling the time-dependent water wave stability of human hair. JOURNAL OF COSMETIC SCIENCE 2010; 61:31-38. [PMID: 20211115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Accepted: 06/15/2009] [Indexed: 05/28/2023]
Abstract
The viscoelastic bending recovery of human hair is described by a hydro-rheologically complex, two-phase model, where the humidity dependence of the pertinent parameters as well as the effects of physical aging are known. Model calculations are conducted to assess the consequences of the time- and humidity-dependent bending recovery of human hair for the formation and the stability of the water wave. It is shown that a hair fiber that has been set in bending will achieve at 65% RH a recovery of about 50% after about ten times its storage time prior to release, if it is a non-aging material. However, aging drastically slows the recovery process so that it approaches an apparent "equilibrium," final recovery value of about 60%. The values of final recovery decrease linearly with water content, vanishing as expected at maximum water content, where the hair fiber is above its glass transition. The calculations further show that damage to the elastic modulus, attributed to the intermediate filaments, is expected to reduce recovery and thus enhance fiber set. The calculations demonstrate that it is in fact the phenomenon of physical aging that makes water waving a feasible and practically successful process for hair styling.
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107
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Wang S, Li Y, Ji YC, Lin CM, Man C, Zheng XX. The most efficient follicular regenerating unit and the smallest follicular regenerating unit: potential treatments for hair loss. Med Hypotheses 2009; 73:1035-7. [PMID: 19545954 DOI: 10.1016/j.mehy.2009.05.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Revised: 05/14/2009] [Accepted: 05/17/2009] [Indexed: 02/05/2023]
Abstract
Hair loss affects many people, especially adult males. An effective treatment is hair transplantation which involves harvesting hair grafts from a donor site and relocating them to a bald site. However, this traditional method, equivalent to one-to-one transplantation, simply redistributes hair rather than increases the number of existing hairs. Although hair transplantation is actually the transplantation of hair follicle (HF), it has been confirmed that whole HFs could be reformed from parts of HFs containing different constituents, implying the existence of more efficient and smaller HF regenerating units in a whole HF. Thus we hypothesize that the most efficient follicular regenerating unit (EFRU) and the smallest follicular regenerating unit (SFRU) could be found in whole HFs. As a result, the one-to-many hair transplantation would be achieved in clinic. One-to-many means to double or triple the number of hairs. In order to test and verify the hypothesis, we design a method called hair follicle micro-dissection (HFM) which aims to help find the regenerating units and increase the number of hair for transplantation. The postulation may provide a more mature and realistic treatment for hair loss if it proved to be practical.
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108
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Gunn DA, Rexbye H, Griffiths CEM, Murray PG, Fereday A, Catt SD, Tomlin CC, Strongitharm BH, Perrett DI, Catt M, Mayes AE, Messenger AG, Green MR, van der Ouderaa F, Vaupel JW, Christensen K. Why some women look young for their age. PLoS One 2009; 4:e8021. [PMID: 19956599 PMCID: PMC2779449 DOI: 10.1371/journal.pone.0008021] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Accepted: 10/25/2009] [Indexed: 01/15/2023] Open
Abstract
The desire of many to look young for their age has led to the establishment of a large cosmetics industry. However, the features of appearance that primarily determine how old women look for their age and whether genetic or environmental factors predominately influence such features are largely unknown. We studied the facial appearance of 102 pairs of female Danish twins aged 59 to 81 as well as 162 British females aged 45 to 75. Skin wrinkling, hair graying and lip height were significantly and independently associated with how old the women looked for their age. The appearance of facial sun-damage was also found to be significantly correlated to how old women look for their age and was primarily due to its commonality with the appearance of skin wrinkles. There was also considerable variation in the perceived age data that was unaccounted for. Composite facial images created from women who looked young or old for their age indicated that the structure of subcutaneous tissue was partly responsible. Heritability analyses of the appearance features revealed that perceived age, pigmented age spots, skin wrinkles and the appearance of sun-damage were influenced more or less equally by genetic and environmental factors. Hair graying, recession of hair from the forehead and lip height were influenced mainly by genetic factors whereas environmental factors influenced hair thinning. These findings indicate that women who look young for their age have large lips, avoid sun-exposure and possess genetic factors that protect against the development of gray hair and skin wrinkles. The findings also demonstrate that perceived age is a better biomarker of skin, hair and facial aging than chronological age.
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109
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[Beautiful hair, beautiful nails-even with aging!]. REVUE MEDICALE SUISSE 2009; 5:2425. [PMID: 20052845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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110
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Nagase S, Kajiura Y, Mamada A, Abe H, Shibuichi S, Satoh N, Itou T, Shinohara Y, Amemiya Y. Changes in structure and geometric properties of human hair by aging. JOURNAL OF COSMETIC SCIENCE 2009; 60:637-648. [PMID: 20038352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Accepted: 05/12/2009] [Indexed: 05/28/2023]
Abstract
To clarify hair changes by aging, the effect of age on hair properties was investigated from macro- to microscopic view points. Sensory hair luster tests were performed on 230 Japanese females from 10 to 70 years of age, revealing that hair luster decreases with age. The age dependence of the hair diameter and the ellipticity of the hair cross section could not explain luster reduction by aging. It has been determined that an irregular increase in fiber curvature occurs with age and is a cause of luster reduction with aging. A detailed structural analysis by synchrotron radiation microbeam X-ray diffraction revealed that the inhomogeneity in the lateral distribution of the hair microstructure increased with age and relates to the irregular increase in curvature. Such an increase in curvature is one of the important factors that leads to a poor alignment of hairs and luster reduction, and is related to the appearance of aging hair.
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111
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Villano JS, Ogden BE, Yong PP, Lood NM, Sharp PE. Morphometrics and pelage characterization of longtailed macaques (Macaca fascicularis) from Pulau Bintan, Indonesia; Singapore; and Southern Vietnam. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2009; 48:727-733. [PMID: 19930820 PMCID: PMC2786926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Revised: 03/20/2009] [Accepted: 05/18/2009] [Indexed: 05/28/2023]
Abstract
Cynomolgus (or longtailed) macaques (Macaca fascicularis) are used extensively as laboratory animals in biomedical research. Their use in Singapore, an emerging biomedical hub in Southeast Asia, is now increasing widely, with research subjects currently originating from Singapore, Vietnam, and Pulau Bintan, Indonesia. Limited data exist on the genetic and phenotypic polymorphisms and phylogenetic relationships of these groups, and the animals are used as research subjects without regard to potential differences or homogeneity. Here we characterize their phenotypes by using established primatology tools to detail morphometrics and pelage erythrism and saturation. Pelage analyses supported the Gloger rule, in which heavily pigmented forms predominate near the equator, with Singaporean and Bintan macaques having darker pelage than Vietnamese macaques. Morphometric variation patterns suggest a tendency toward insular dwarfism and correlate generally with the Bergmann rule, in which body mass increases with latitude and colder climate. Although the 3 populations all belong to the nominotypical subspecies M. f. fascicularis, phenotypic differences are evident and are valuable tools to analyze their phylogeographic history and phylogenetic relationships.
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112
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Chang SH, Jobling S, Brennan K, Headon DJ. Enhanced Edar signalling has pleiotropic effects on craniofacial and cutaneous glands. PLoS One 2009; 4:e7591. [PMID: 19855838 PMCID: PMC2762540 DOI: 10.1371/journal.pone.0007591] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Accepted: 09/29/2009] [Indexed: 12/31/2022] Open
Abstract
The skin carries a number of appendages, including hair follicles and a range of glands, which develop under the influence of EDAR signalling. A gain of function allele of EDAR is found at high frequency in human populations of East Asia, with genetic evidence suggesting recent positive selection at this locus. The derived EDAR allele, estimated to have reached fixation more than 10,000 years ago, causes thickening of hair fibres, but the full spectrum of phenotypic changes induced by this allele is unknown. We have examined the changes in glandular structure caused by elevation of Edar signalling in a transgenic mouse model. We find that sebaceous and Meibomian glands are enlarged and that salivary and mammary glands are more elaborately branched with increased Edar activity, while the morphology of eccrine sweat and tracheal submucosal glands appears to be unaffected. Similar changes to gland sizes and structures may occur in human populations carrying the derived East Asian EDAR allele. As this allele attained high frequency in an environment that was notably cold and dry, increased glandular secretions could represent a trait that was positively selected to achieve increased lubrication and reduced evaporation from exposed facial structures and upper airways.
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113
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Lee S, Zürcher S, Dorcier A, Luengo GS, Spencer ND. Adsorption and lubricating properties of poly(l-lysine)-graft-poly(ethylene glycol) on human-hair surfaces. ACS APPLIED MATERIALS & INTERFACES 2009; 1:1938-1945. [PMID: 20355818 DOI: 10.1021/am900337z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We have characterized the adsorption and lubricating properties of the polycation-PEG graft copolymer poly(l-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) on human-hair surfaces by means of X-ray photoelectron spectroscopy (XPS), fluorescence microscopy, and atomic force microscopy (AFM). XPS measurements indicated that PLL-g-PEG copolymers spontaneously adsorbed onto the surface of bleached-hair samples (a good model of a weathered, damaged hair surface for cosmetic care applications) from an aqueous solution. Further treatment with cationic surfactants present in common shampoo formulations removed the adsorbed PLL-g-PEG from the hair samples. Fluorescence microscopy showed that the adsorption of PLL-g-PEG onto the hair samples from an aqueous polymer solution occurred inhomogeneously. Nanotribological studies with AFM (friction vs load plots) revealed that the relationship between load and friction was approximately linear for all hair samples, while the slopes of the plots varied considerably along the hair sample surface. Under ambient, "dry" conditions, the frictional properties of the bleached, bleached + PLL-g-PEG-treated, and bleached + PLL-g-PEG-treated and subsequently surfactant-treated hair samples did not reveal a clear difference. In distilled water, however, the bleached + PLL-g-PEG-treated hair samples showed statistically lower frictional properties than simply bleached or bleached + PLL-g-PEG-treated and subsequently surfactant-treated hair samples. Overall, the three instrumental techniques have consistently shown that the adsorption of PLL-g-PEG onto the hair sample surface occurs unevenly, which can be ascribed to the intrinsically heterogeneous properties of the human-hair surface. A control experiment, involving an injection of concentrated PLL-g-PEG solution into a liquid cell where an AFM tip was already scanning over a specific area (line scan mode), revealed an immediate and apparent reduction in the frictional force. Despite the inhomogeneity of the hair surface, the adsorption of the polymer seems to be extremely effective in promoting lubrication of the fiber. This suggests that the adsorbed graft copolymers act as a boundary lubricant on the hair surface. The presence of a more organized, brushlike layer of polymers contrasts with the usual random adsorption of chains that is believed to be present in the case of linear polyelectrolytes that are nowadays applied for shampoos and conditioners in the cosmetic or textile industries.
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DAMMERT K. THE MORPHOLOGY OF THE HAIR FOLLICLES DURING TUMOR PROMOTION IN MICE. ACTA PATHOLOGICA MICROBIOLOGICA SCANDINAVICA 2009; 55:141-50. [PMID: 13883318 DOI: 10.1111/j.1699-0463.1962.tb04111.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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115
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Robbins C. The cell membrane complex: three related but different cellular cohesion components of mammalian hair fibers. JOURNAL OF COSMETIC SCIENCE 2009; 60:437-465. [PMID: 19691940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Accepted: 02/11/2009] [Indexed: 05/28/2023]
Abstract
The structure, chemistry and physical properties of the cell membrane complex (CMC) of keratin fibers are reviewed, highlighting differences in the three types of CMC. Starting with Rogers' initial description of the CMC in animal hairs, several important developments have occurred that will be described, adding new details to this important structure in mammalian hair fibers. These developments show that essentially all of the covalently bound fatty acids of the beta layers are in the cuticle and exist as monolayers. The beta layers of the cortex are bilayers that are not covalently bonded but are attached by ionic and polar linkages on one side to the cortical cell membranes and on the other side to the delta layer. The delta layer between cortical cells consists of five sublayers; its proteins are clearly different from the delta layer that exists between cuticle cells. The cell membranes of cuticle cells are also markedly different from the cell membranes of cortical cells. Models with supporting evidence are presented for the three different types of cell membrane complex: cuticle-cuticle CMC, cuticle-cortex CMC, and cortex-cortex CMC.
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116
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Sarode B, Beermann F. Mysteries of salt and pepper. Pigment Cell Melanoma Res 2009; 22:380-1. [PMID: 19522747 DOI: 10.1111/j.1755-148x.2009.00591.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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117
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Ong KK, Elks CE, Li S, Zhao JH, Luan J, Andersen LB, Bingham SA, Brage S, Smith GD, Ekelund U, Gillson CJ, Glaser B, Golding J, Hardy R, Khaw KT, Kuh D, Luben R, Marcus M, McGeehin MA, Ness AR, Northstone K, Ring SM, Rubin C, Sims MA, Song K, Strachan DP, Vollenweider P, Waeber G, Waterworth DM, Wong A, Deloukas P, Barroso I, Mooser V, Loos RJ, Wareham NJ. Genetic variation in LIN28B is associated with the timing of puberty. Nat Genet 2009; 41:729-33. [PMID: 19448623 PMCID: PMC3000552 DOI: 10.1038/ng.382] [Citation(s) in RCA: 249] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Accepted: 04/21/2009] [Indexed: 11/09/2022]
Abstract
The timing of puberty is highly variable. We carried out a genome-wide association study for age at menarche in 4,714 women and report an association in LIN28B on chromosome 6 (rs314276, minor allele frequency (MAF) = 0.33, P = 1.5 × 10(-8)). In independent replication studies in 16,373 women, each major allele was associated with 0.12 years earlier menarche (95% CI = 0.08-0.16; P = 2.8 × 10(-10); combined P = 3.6 × 10(-16)). This allele was also associated with earlier breast development in girls (P = 0.001; N = 4,271); earlier voice breaking (P = 0.006, N = 1,026) and more advanced pubic hair development in boys (P = 0.01; N = 4,588); a faster tempo of height growth in girls (P = 0.00008; N = 4,271) and boys (P = 0.03; N = 4,588); and shorter adult height in women (P = 3.6 × 10(-7); N = 17,274) and men (P = 0.006; N = 9,840) in keeping with earlier growth cessation. These studies identify variation in LIN28B, a potent and specific regulator of microRNA processing, as the first genetic determinant regulating the timing of human pubertal growth and development.
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118
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Ong KK, Elks CE, Li S, Zhao JH, Luan J, Andersen LB, Bingham SA, Brage S, Smith GD, Ekelund U, Gillson CJ, Glaser B, Golding J, Hardy R, Khaw KT, Kuh D, Luben R, Marcus M, McGeehin MA, Ness AR, Northstone K, Ring SM, Rubin C, Sims MA, Song K, Strachan DP, Vollenweider P, Waeber G, Waterworth DM, Wong A, Deloukas P, Barroso I, Mooser V, Loos RJ, Wareham NJ. Genetic variation in LIN28B is associated with the timing of puberty. Nat Genet 2009. [PMID: 19448623 DOI: 10.1038/ng.382.genetic] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
The timing of puberty is highly variable. We carried out a genome-wide association study for age at menarche in 4,714 women and report an association in LIN28B on chromosome 6 (rs314276, minor allele frequency (MAF) = 0.33, P = 1.5 × 10(-8)). In independent replication studies in 16,373 women, each major allele was associated with 0.12 years earlier menarche (95% CI = 0.08-0.16; P = 2.8 × 10(-10); combined P = 3.6 × 10(-16)). This allele was also associated with earlier breast development in girls (P = 0.001; N = 4,271); earlier voice breaking (P = 0.006, N = 1,026) and more advanced pubic hair development in boys (P = 0.01; N = 4,588); a faster tempo of height growth in girls (P = 0.00008; N = 4,271) and boys (P = 0.03; N = 4,588); and shorter adult height in women (P = 3.6 × 10(-7); N = 17,274) and men (P = 0.006; N = 9,840) in keeping with earlier growth cessation. These studies identify variation in LIN28B, a potent and specific regulator of microRNA processing, as the first genetic determinant regulating the timing of human pubertal growth and development.
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119
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Umeda-Ikawa A, Shimokawa I, Doi K. Time-course expression profiles of hair cycle-associated genes in male mini rats after depilation of telogen-phase hairs. Int J Mol Sci 2009; 10:1967-1977. [PMID: 19564932 PMCID: PMC2695260 DOI: 10.3390/ijms10051967] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Revised: 04/23/2009] [Accepted: 04/24/2009] [Indexed: 11/16/2022] Open
Abstract
Jcl:WistarTGN(ARGHGEN)1Nts rat (Mini rat) is a growth hormone (GH)-deficient transgenic rat. The hair cycle in the dorsal skin of male Mini rats enters a long-lasting telogen phase after eights weeks of age, but depilation can induce a transient hair cycle again. In this study, a time-course profiling of genes expression was done on the dorsal skin of male Mini rats along the progression of depilation-induced hair cycle using DNA microarray analysis. As a result, 1,215 probe sets including 1,171 hair cycle-related ones showed more than 3-fold changes in expression compared with that in before-depilation telogen phase. The present data will contribute to elucidating the mechanisms of hair cycle regulation and should lead to the identification of novel molecular targets for hair growth and/or depilation agents.
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120
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Chernova OF. [Skin derivatives in ontogeny and phylogeny of vertebrates]. IZVESTIIA AKADEMII NAUK. SERIIA BIOLOGICHESKAIA 2009:218-227. [PMID: 19391480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The skin of vertebrates has numerous and diverse derivatives, either located within the epithelial sheet itself (glands) or extending above its surface (teeth, scales, feathers, hairs, etc.). Many of them have a modular structure and constitute structural-functional units. Ontogenetically, all skin derivatives are of ectomesodermal origin, and their morphogenesis is subject to metabolic control, heterochronies (divergence in the timing of origination and development), and regulation by means of tissue interactions and molecular signaling via similar pathways. The diversification (origination of morphological diversity) of skin derivatives within the same morphological type is explained by the development of new generations of ectomesodermal structures separated be heterochronies and regulated by changes in the gradients of molecular signaling pathways under the influence of environmental factors. Evolutionary relationships between the majority of skin derivatives are obscure, except for teeth and glands associated with sensory organs, which evolved together with the latter. Apparently, many vertebrate skin derivatives (scales, feathers, hairs, and glands) originated as innovations at nodal stages of phylogeny and subsequently evolved convergently or in parallel.
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Kharin A, Varghese B, Verhagen R, Uzunbajakava N. Optical properties of the medulla and the cortex of human scalp hair. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:024035. [PMID: 19405764 DOI: 10.1117/1.3116712] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
An increasing number of applications, including non- or minimally invasive diagnostics and treatment as well as various cosmetic procedures, has resulted in a need to determine the optical properties of hair and its structures. We report on the measurement of the total attenuation coefficient of the cortex and the medulla of blond, gray, and Asian black human scalp hair at a 633-nm wavelength. Our results show that for blond and gray hair the total attenuation coefficient of the medulla is more than 200 times higher compared to that of the cortex. This difference is only 1.5 times for Asian black hair. Furthermore, we present the total attenuation coefficient of the cortex of blond, gray, light brown, and Asian black hair measured at wavelengths of 409, 532, 633, 800, and 1064 nm. The total attenuation coefficient consistently decreases with an increase in wavelength, as well as with a decrease in hair pigmentation. Additionally, we demonstrate the dependence of the total attenuation coefficient of the cortex and the medulla of Asian black hair on the polarization of incident light. A similar dependence is observed for the cortex of blond and gray hair but not for the medulla of these hair types.
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Porter CE, Dixon F, Khine CC, Pistorio B, Bryant H, de la Mettrie R. The behavior of hair from different countries. JOURNAL OF COSMETIC SCIENCE 2009; 60:97-109. [PMID: 19450412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The properties of curly hair from different countries were assessed using geometrical measurements from a laser scanning micrometer and a new hair shape classification method. In addition, tensile tests, 2-D gel electrophoresis, and differential scanning calorimetry (DSC) were performed. Results concluded that hair characteristics are influenced by the degree of curl. For example, curlier hair tended to be more fragile. Interestingly, the degree of curl in hair also was dependent upon the country of origin. DSC and 2-D gel electrophoresis showed that the thermal behavior and the protein markers in hair differed as a function of hair origin. The variability seen in hair characteristics may potentially influence how the hair responds to treatment and these differences could be caused by regional and cultural diversities in the population from where the hair originated.
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123
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Yamazaki F, Kinoshita K, Sone R. Interactive effects between isometric exercise and mental stress on the vascular responses in glabrous and nonglabrous skin. J Physiol Sci 2009; 59:137-42. [PMID: 19340554 PMCID: PMC10717583 DOI: 10.1007/s12576-009-0019-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Accepted: 12/16/2008] [Indexed: 10/20/2022]
Abstract
Cutaneous vascular responses to mental arithmetic (MA) and handgrip exercise (HG) were studied independently and combined at different local skin temperatures (T (loc)). MA and HG induced (P < 0.05) vasoconstrictor responses in glabrous and nonglabrous skin at a higher level of T (loc), resulting in a nonadditive effect of these two stresses.
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Kania M, Mikołajewska D, Marycz K, Kobielarz M. Effect of diet on mechanical properties of horse's hair. Acta Bioeng Biomech 2009; 11:53-57. [PMID: 20131751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The aim of this research was to assess the effect of diet supplementation with zinc and copper, in different chemical forms (organic and inorganic), on the mechanical properties of the hair of healthy English thoroughbred horses. Hairs were taken from 18 horses which had been fed with oats and hay for a period of 110 days. Twelve of the horses had been additionally given a daily dose of 700 g of highquality 44-ingredients Fohlengold St-Hippolyt muesli made by Muhle Ebert Dilheim. Six of them had received the muesli-containing organic zinc and copper (OS), while the other six horses had received the muesli-containing inorganic zinc and copper (IS). The mechanical properties of the hairs before and after the supplementation period were tested in a Synergie 100 (MTS) testing machine. Each of the hairs was loaded at a constant rate of 20 mm/min until rupture. Young modulus (E), breaking stress (Ru) and yield point (Rs) of the particular hairs were determined. No significant changes in the mechanical parameters were observed in the reference group in which the horses were fed with only oats and hay for the whole experimental period of 110 days. The supplementation of the diet with inorganic zinc and copper resulted in an increase in the elasticity and diameter of the hairs and in a simultaneous reduction in their strength. Whereas organic zinc and copper caused an increase in the elasticity and strength of the hairs and a simultaneous reduction in their diameter. It has been shown that the organic form of the supplemented trace zinc and copper (mainly copper) elements has a beneficial effect on the mechanical properties of the hairs since it results in an increase in both their elasticity and strength.
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Bystrova K. Novel mechanism of human fetal growth regulation: a potential role of lanugo, vernix caseosa and a second tactile system of unmyelinated low-threshold C-afferents. Med Hypotheses 2008; 72:143-6. [PMID: 19004563 DOI: 10.1016/j.mehy.2008.09.033] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Revised: 08/21/2008] [Accepted: 09/03/2008] [Indexed: 11/18/2022]
Abstract
Novel hypothesis of human fetal growth regulation in amniotic fluid environment integrates lanugo, vernix caseosa and a second tactile system of unmyelinated low-threshold C-afferents - all three forming a unique natural instrument powerfully speeding fetal growth during mid-gestation and lowering its tempo at the end of gestation. Repeated oscillations of lanugo hairs encased by vernix caseosa during fetal movements in amniotic fluid activate highly sensitive mechanoreceptors connected to unmyelinated C-afferents, which prime function is to conduct originated impulses from all fetal skin dermatoms via spinal cord and to activate vagal sensory zone, hypothalamus and insular cortex, for concomitant promotion of the anti-stress effect through oxytocin release, and stimulation of fetal growth by the incretin effect of gastrointestinal hormones.
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