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Hair Shaft (hair + shaft)
Selected AbstractsPolarized Raman microspectroscopy on intact human hairJOURNAL OF BIOPHOTONICS, Issue 5 2008K. R. Ackermann Abstract Polarization-resolved Raman microspectroscopy with near-infrared laser excitation was applied to intact human hair in order to non-invasively investigate the conformation and orientation of the polypeptide chains. By varying the orientation of the hair shaft relative to the polarization directions of the laser/analyzer, a set of four polarized Raman spectra is obtained; this allows to simultaneously determine both the secondary structure of hair proteins and the orientation of the polypeptide strands relative to the axis of the hair shaft. For the amide I band, results from a quantitative analysis of the polarized Raman spectra are compared with theoretically expected values for fibers with uniaxial symmetry. Based on the polarization behavior of the amide I band and further vibrational bands, a partial ordering of ,-helical polypeptide strands parallel to the hair shaft can be concluded. We suggest that this microspectroscopic approach may be used for human hair diagnostics by detecting structural or orientational alterations of keratins. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Degeneration of Nuclei and Mitochondria in Human HairsJOURNAL OF FORENSIC SCIENCES, Issue 2 2009Charles A. Linch B.S. Abstract:, It is generally accepted that nuclei degrade in developing hair shafts but the point at which such occurs has not been investigated. The fate of mitochondria in the keratinizing hair shaft has been less clear. This study uses transmission electron microscopy to investigate when nuclei and mitochondria are no longer visible in the developing hair shaft. Serial sections were obtained from anagen head hairs absent follicles in order to determine the sequence of degradation of nuclei and mitochondria in the hair shaft by starting at the root bulb and proceeding toward the hair tip. It was demonstrated that nuclei and mitochondria become invisible in the keratinizing hair shaft at about the same time. This was found to occur fairly early in the process at the level of the hair shaft where the hair cuticle becomes permanent. [source] A study of the human hair structure with a Zernike phase contrast X-ray microscopeJOURNAL OF MICROSCOPY, Issue 2 2007HWA SHIK YOUN Summary We have observed the internal structure of human hair shafts with a transmission Zernike phase contrast hard X-ray microscope. Due to the high spatial resolution and the high contrast of the microscope, we could image scales, macrofibrils, medulla and melanin without staining. The structure of a black hair shaft is compared with that of a white one. [source] The neuroepithelial stem cell protein nestin is a marker of the companion cell layer of the adult and developing human hair follicleBRITISH JOURNAL OF DERMATOLOGY, Issue 3 2009D. Krahl Summary Background, The interface between the inner root sheath (IRS) and the outer root sheath (ORS) represents a slippage plane for the hair shaft to evolve from the pilar canal to the skin surface. Interposed between the IRS and ORS is a single cell layer which is believed to represent the angle point of that slippage plane, termed the companion cell layer (CCL). The CCL is cited in most of the literature as part of the ORS. Objectives, To describe the expression pattern of nestin, a neuroepithelial stem cell protein, in the adult and developing human hair follicle. Methods, Immunohistochemical evaluation with a monoclonal antibody against nestin was performed using standard techniques. Results Nestin is selectively expressed in the CCL of the adult anagen and late stage fetal hair follicles. Early stages of hair follicle development are negative for nestin expression. Conclusions, The selective demarcation of the CCL by nestin highlights the unique feature of this follicular cell layer and raises the question of whether the CCL should not be better conceptualized as a part of the IRS rather than the ORS. The results of the present study, together with published ultrastructural data, also suggest that the slippage plane for the evolving hair shaft may be located at the interface between the CCL and the ORS. [source] 2331: Are the Meibomian glands "hair follicles without a hair shaft" ?ACTA OPHTHALMOLOGICA, Issue 2010E KNOP Purpose The Meibomian glands (MG) are atypically large sebaceous glands in the eyelids with numerous generations of secretory acini along an extensive central duct. They share similarities with the ciliary hairs in development, and hyper-keratinisation leading to obstructive MG dysfunction (MGD) represents the typical pathology. It was hence investigated which structural similarities they share with cilia. Methods Conjunctival whole-mounts including the lid margin from ten normal human body donors were embedded in paraffin. Serial sections were stained by H&E, Masson-Goldners stain and by immunohistochemistry (IHC) against cytokeratins and associated proteins. Results The terminal part (excretory duct) of the MG central duct is an ingrowth of epidermis similar to the hair follicles of the cilia. Characterization of individual cytokeratinis by IHC showed that CK14, a marker for undifferentiated cells, was expressed in the basal cell layer of the skin, MG ducts and the secretory acini. The excretory duct epithelium expressed the skin keratin CK10 and the keratinisation marker involucrin but in proximal direction along the central duct full cornification as well as both markers were gradually lost. Filaggrin, however, a marker for incipient stages of keratinisation located in keratohyalin granules continued in the superficial epithelial layer all along the MG ductal system. Conclusion All parts of the normal human MG ductal system have signs of incipient keratinisation and preserve a commitment to full cornification. This supports the assumption that the MG are basically "hair follicles without a hair shaft" in which the progression to full epithelial cornification is apparently blocked during embryological development but may reoccur under pathological influences. Support DFG KN317/11 [source] Keratinisation status and cytokeratins of the human Meibomian gland epitheliumACTA OPHTHALMOLOGICA, Issue 2009E KNOP Purpose The Meibomian gland (MG) is an indispensable component of the functional anatomy of the ocular surface. Increasing evidence points to a high impact of hyper-keratinisation as a major cause of obstructive MG dysfunction (MGD) and evaporative dry eye. Information of normal keratinisation status and cytokeratin composition of the human MG is limited. Methods Conjunctival whole-mount specimens including the lid margin from ten body donors of older age were embedded in paraffin. Serial sections were stained by H&E and Masson-Goldner stain and by immunohistochemistry with an antibody panel to cytokeratins. Results In conventional stains, the MG shows distinct similarities with the pilo-sebaceous unit of the cilia. The keratinised skin epithelium extended into the terminal part of the MG excretory duct similar to the hair follicle. Preliminary IHC results showed that the epithelium was positive there for the skin keratin CK10. Along the central duct the keratinisation CK10 expression was gradually lost similar to keratinisation marker involucrin. However, filaggrin, a marker for incipient stages of keratinisation and located in keratohyalin granules continued in the superficial layer of the duct epithelium all along the Meibomian central ductal system. CK14 a marker for basal undifferentiated cells showed a homogenous expression all along the basal cell layer of the MG ducts and the acini. Conclusion The MG shares similarities with the cilia in embryology, in structure and in the cytokeratin composition. It can hence be regarded as a "hair without a hair shaft". All parts of the MG ducts have signs of incipient keratinisation and preserve a commitment to keratinisation. Upregulation in MGD explain hyper-keratinisation as a typical event in obstructive MGD. [source] Degeneration of Nuclei and Mitochondria in Human HairsJOURNAL OF FORENSIC SCIENCES, Issue 2 2009Charles A. Linch B.S. Abstract:, It is generally accepted that nuclei degrade in developing hair shafts but the point at which such occurs has not been investigated. The fate of mitochondria in the keratinizing hair shaft has been less clear. This study uses transmission electron microscopy to investigate when nuclei and mitochondria are no longer visible in the developing hair shaft. Serial sections were obtained from anagen head hairs absent follicles in order to determine the sequence of degradation of nuclei and mitochondria in the hair shaft by starting at the root bulb and proceeding toward the hair tip. It was demonstrated that nuclei and mitochondria become invisible in the keratinizing hair shaft at about the same time. This was found to occur fairly early in the process at the level of the hair shaft where the hair cuticle becomes permanent. [source] A study of the human hair structure with a Zernike phase contrast X-ray microscopeJOURNAL OF MICROSCOPY, Issue 2 2007HWA SHIK YOUN Summary We have observed the internal structure of human hair shafts with a transmission Zernike phase contrast hard X-ray microscope. Due to the high spatial resolution and the high contrast of the microscope, we could image scales, macrofibrils, medulla and melanin without staining. The structure of a black hair shaft is compared with that of a white one. [source] Trichothiodystrophy-like Hair Abnormalities in a Child with Keratitis Ichthyosis Deafness SyndromePEDIATRIC DERMATOLOGY, Issue 4 2008L. De Raeve M.D., Ph.D. It appears to be genetically heterogeneous and may be caused by mutations in the connexin 26 (Cx26) gene (GJB2) or in the connexin 30 gene. It is characterized by the association of ichthyosis-like skin lesions, hearing loss, and vascularizing keratitis. We report the clinical and molecular findings in a 5-year-old girl with keratitis ichthyosis deafness syndrome. DNA sequencing in our patient revealed a p.Ser17Phe mutation in GJB2. Besides the typical clinical features of keratitis ichthyosis deafness syndrome, a peculiar intriguing finding not previously described in the literature in this condition was that polarizing light microscopy of the scalp hair in our patient revealed striking bright and dark bands as seen in trichothiodystrophy. Amino acid analysis of the hair sample also disclosed a reduced cysteine index. We emphasize that it would be of great benefit to examine hair shafts in other patients with keratitis ichthyosis deafness syndrome for trichothiodystrophy-like abnormalities. [source] Adenosine increases anagen hair growth and thick hairs in Japanese women with female pattern hair loss: A pilot, double-blind, randomized, placebo-controlled trialTHE JOURNAL OF DERMATOLOGY, Issue 12 2008Hajimu OURA ABSTRACT Adenosine upregulates the expression of vascular endothelial growth factor and fibroblast growth factor-7 in cultured dermal papilla cells. It has been shown that, in Japanese men, adenosine improves androgenetic alopecia due to the thickening of thin hair due to hair follicle miniaturization. To investigate the efficacy and safety of adenosine treatment to improve hair loss in women, 30 Japanese women with female pattern hair loss were recruited for this double-blind, randomized, placebo-controlled study. Volunteers used either 0.75% adenosine lotion or a placebo lotion topically twice daily for 12 months. Efficacy was evaluated by dermatologists and by investigators and in phototrichograms. As a result, adenosine was significantly superior to the placebo according to assessments by dermatologists and investigators and by self-assessments. Adenosine significantly increased the anagen hair growth rate and the thick hair rate. No side-effects were encountered during the trial. Adenosine improved hair loss in Japanese women by stimulating hair growth and by thickening hair shafts. Adenosine is useful for treating female pattern hair loss in women as well as androgenetic alopecia in men. [source] Marie Unna hereditary hypotrichosis: report of a Chinese family and evidence for genetic heterogeneityCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 5 2004K. L. Yan Summary Marie Unna hereditary hypotrichosis (MUHH) is a rare autosomal dominant disorder with progressive hair loss starting in early childhood and aggravating at puberty. Several studies have mapped the MUHH gene to chromosome 8p21. Here we report a Chinese MUHH family with variable phenotypes. All affected individuals have anomalies affecting both hair density and hair shafts. Major clinical characteristics, disease history and histological examination support the diagnosis of MUHH, but the features of scarring in this kindred are modest and none of the patients have vertex hair loss, which is in contrast with typical MUHH. We now report genotyping and linkage analysis using 11 polymorphic microsatellite markers spanning the MUHH locus at 8p. Two-point linkage analysis using these markers revealed significant exclusion of this locus (log of the odds scores < , 2) at , = 0 indicating that there is a range of clinical presentations in MUHH, and that more than one genetic locus is responsible for the disorder. [source] | ||||||||||