Identification of live hair cells in rat cochlear sections in culture with FM1-43 fluorescent dye

Cochlear hair cells are presumed to live in culture for many days, yet they are difficult to identify in cultured tissues. We stained hair cells in cochlear sections with FM1-43 and cultured them in collagen matrix. Three rows of outer hair cells and a single row of inner ones were distinguished by staining with FM1-43. Fixation of the sections with paraformaldehyde caused loss of the FM1-43 fluorescence, indicating that FM1-43 stained only live hair cells. In sections cultured for 48 h, almost all hair cells were still positive with FM1-43. Culture with gentamycin caused loss of FM1-43-positive cells. In serum-free, long-term cultures (15 days) performed without antibiotics or neurotrophins, the row alignment of FM1-43-positive hair cells was still maintained. Membranous labyrinth-like vacuoles enveloping hair cells were formed in the collagen matrix. Accordingly, FM1-43 is an efficient marker for identifying live hair cells in cultured tissues. Moreover, cochlear hair cells are revealed to live for weeks in serum-free culture without exogenous neurotrophins.     

Ultrastructure of human scalp hair shafts as revealed by freeze-substitution fixation

Human scalp hair is important as a diagnostic clue to many diseases, in medical jurisprudential investigations, and also as a subject of cosmetic treatments. While many ultrastructural studies of the human hair root including the hair follicle have been reported, few studies have been done on the human hair shaft. We report here the ultrastructure of human scalp hair shafts prepared by a rapid-freezing technique followed by freeze-substitution fixation that allows the observation of fine cell structures. Healthy scalp hair shafts from Japanese females 12–13 years of age were rapid-frozen and then freeze-substituted in OsO₄-acetone. In addition, this technique was applied to the study of some changes of the hair shafts (i.e., hair damaged by thioglycolic acid cold permanent waving and white hair). By this method, the hair shaft was rapid-frozen throughout without appreciable ice damage although the hair shaft was nearly 100 μm in diameter. The rapid-freezing technique resulted in excellent preservation of the ultrastructure of the hair shafts: lamellar structures in the cuticle and fine fibrous ultrastructures in the cortex were observed without chemical treatments. Thioglycolic acid treatment affected the ultrastructure of both the cuticle and the cortex. Except for the absence of melanin granules, no significant differences in the ultrastructure were observed between white hair and black hair. The rapid-freezing technique followed by freeze-substitution fixation appears to be the most reliable approach for the morphological evaluation of fully keratinized cells and tissues. Anat. Rec. 251:406–413, 1998. © 1998 Wiley-Liss, Inc.     

Differentiating neoplasms of hair germ

Differentiating neoplasms of hair germ are benign epithelial-mesenchymal tumours of skin in which hair follicle development may be partly or completely recapitulated. The epithelial component is equivalent to the hair germ. The mesenchymal component is equivalent to the dermal papilla. Epithelial-mesenchymal interaction results in the morphogenesis of hair follicles. In neoplasms showing stromal induction, there is centrifugal organizations: hair bulbs are found at the periphery of tumour lobules and hairs are projected centrally to lie within small keratinizing cysts. Neoplasms of hair germ without advanced morpho-differentiation are termed ;trichoblastomas', and those neoplasms in which hair follicle development is advanced are called ;trichogenic trichoblastomas'.     

Analysis of tests used to differentiate Trichophyton rubrum from Trichophyton mentagrophytes.

Differential identification of Trichophyton rubrum and Trichophyton mentagrophytes was evaluated by using the standard in vitro hair perforation test as a criterion for identification and comparing its effectiveness with that of nine other tests used to differentiate these two taxa. Correlation and multiple regression analysis showed that no single test or combination of these tests was able to make the differentiation as effectively as the standard in vitro hair perforation test. Using relative error analysis, we suggest an identification scheme based upon selective utilization of potato-carrot agar for sporulation and the standard in vitro hair perforation test. Using potato-carrot agar for development of typical microconidia on each of the nonsporulating primary isolates and subsequently performing the standard in vitro hair perforation test only on those isolates that failed to produce spores on potato-carrot medium, we showed that this combination scheme provides more expedient results, without any sacrifice in reliability, than the standard in vitro hair perforation test alone.     

Cardio-facio-cutaneous (CFC) syndrome: Report of an adult without mental retardation

We report on a 25-year-old woman with typical manifestations of the cardio-facio-cutaneous (CFC) syndrome, but without mental retardation. She had valvular and infundibular pulmonic stenosis, brittle and woolly hair with patchy alopecia, scant body hair, dry and hypohydrotic skin, and characteristic facial traits. To our knowledge, this is the first case of CFC syndrome without mental retardation but typical cutaneous findings. © 1996 Wiley-Liss, Inc.     

Cochlear outer hair cell motility

Normal hearing depends on sound amplification within the mammalian cochlea. The amplification, without which the auditory system is effectively deaf, can be traced to the correct functioning of a group of motile sensory hair cells, the outer hair cells of the cochlea. Acting like motor cells, outer hair cells produce forces that are driven by graded changes in membrane potential. The forces depend on the presence of a motor protein in the lateral membrane of the cells. This protein, known as prestin, is a member of a transporter superfamily SLC26. The functional and structural properties of prestin are described in this review. Whether outer hair cell motility might account for sound amplification at all frequencies is also a critical question and is reviewed here.     

Inhibition of Notch/RBP-J signaling induces hair cell formation in neonate mouse cochleas

Mammalian inner ear hair cells in cochleas are believed to be incapable of regeneration after birth, which hampers treatment of sensorineural hearing impairment mainly caused by hair cell loss. Sensory epithelia of cochleas are composed of hair cells and supporting cells, both of which originate from common progenitors. Notch/RBP-J signaling is an evolutionally conserved pathway involved in specification of various cell types in developmental stage and even in some of postnatal mammalian organs. The specification of hair cell fate from the progenitors is inhibited by Notch/RBP-J signaling in embryonic inner ears. However, its function in postnatal inner ears is unknown. We showed that inhibition of Notch/RBP-J signaling, by either conditional disruption of the Rbpsuh gene or treatment with a -secretase inhibitor, could give rise to ectopic hair cells in the supporting cell region in organs of Corti from neonatal mouse cochleas where hair cells have not been considered to regenerate after birth. We also showed that down-regulation of Hes5 and up-regulation of Math1 were associated with ectopic hair cell induction. These results suggest that Notch/RBP-J signaling inhibits supporting cells from differentiation into hair cells even in postnatal days, implying that inhibitors of Notch/RBP-J signaling can be used to help regenerating hair cells after birth and thus serve for potential treatment of intractable sensorineural hearing impairment caused by hair cell loss without genetical manipulation.N. Yamamoto and K. Tanigaki contributed equally to this work     

Immunobiosensor analysis- of clenbuterol in bovine hair

Due to the potential speed and flexibility of surface plasmon resonance (SPR)-biosensor analysis, the technique is currently being exploited for detection of residues in food. In the present study an antibody-based inhibition assay for analysis of clenbuterol in cattle hair was developed using a Biacore 2000 instrument. Analysis of clenbuterol with and without enhancement with a secondary antibody was compared. A fast extraction method for hair, which enabled direct analysis in the biosensor with no clean up other than microscale ultrafiltration was developed. In contrast to most of the published methods in the area, no organic solvent or solid phase extraction step was needed. The biosensor method was validated by analysis of hair samples from animals treated with clenbuterol and the results were compared to results from GC-MS analysis. The correlation was good (r²=92.7%). The detection limit of the new method was 10 ng g^-1 hair.     

Time-specific occurrence of alopecia in neonatal C57BL mice treated with N-methyl-N-nitrosourea and the therapeutic efficacy of tacrolimus hydrate

Alopecia was induced in male and female neonatal C57BL mice by a single intraperitoneal injection of 60 mg/kg N-methyl-N-nitrosourea (MNU). MNU administration was most effective in the 8-day-old mice and less effective in the 5-day-old mice (at active and early anagen stages of the first hair cycle, respectively). No alopecia was seen in the day 14 MNU-treated animals (at telogen stage of the first hair cycle). MNU effectively induced hair follicular cell apoptosis at the anagen stage by up-regulation of Bax protein without down-modulation of Bcl-2 protein. In day 8 MNU-treated mice, the immunosuppressive agent 0.01% tacrolimus hydrate (FK506), when topically applied for 5 days from 1 day after MNU treatment (before the occurrence of alopecia), decreased the severity of alopecia. However, it did not stimulate hair growth when applied for 5 days from 20 days of age (after occurrence of alopecia).     

Laser hair reduction in the hirsute patient: a critical assessment

Hirsutism affects 5-10% of unselected women, depending on ethnicity and definition. The past two decades have seen the development of lasers for the removal of unwanted hair, using selective destruction of the hair follicle without damage to adjacent tissues. Selective photothermolysis relies on the absorption of a brief radiation pulse by specific pigmented targets, which generates and confines the heat to that selected target. In general, laser hair removal is most successful in patients with lighter skin colours and dark coloured hairs. Some studies have documented the results of laser hair removal in a controlled setting, although few have extended their observations beyond 1 year. In general, treatment with the ruby, alexandrite or diode lasers, or the use of intense pulsed light results in similar success rates, although these are somewhat lower for the neodymium:Yttrium-Aluminum-Garnet (nd:YAG) laser. Overall, laser hair removal should not be considered 'permanent', at least when considering the current data available. Repeated therapies are necessary, although complete alopoecia is rarely achieved and it is unclear at what point the maximum benefit is achieved from multiple therapies. While larger prospective, controlled, blinded and uniform studies are still needed, laser hair removal appears to be a useful adjuvant in the treatment of the hirsute patient.     

Functional and morphological comparisons between cochlear outer hair cells and muscle tissues in the guinea-pig.

The effect of polylysine on the motility of outer hair cells and various muscle types was compared. Poly-L-lysine and its stereoisomer, poly-D-lysine, inhibited acoustically induced length changes of isolated outer hair cells from the guinea-pig hearing organ. The frequency specific displacements of the hearing organ in response to a tone stimulus are also inhibited to polylysine (Brundin et al. 1991). Poly-L-lysine, and its stereoisomer, irreversibly attenuated motile responses to transmural stimulation of guinea-pig ileum, vas deferens and taenia coli in a dose dependent manner, but were without significant effect on motile responses in skeletal and heart muscle. L-lysine, D-lysine, and the negatively charged polyaminoacid poly-L-aspartate, were without significant effect on outer hair cell and smooth muscle motility. The inhibitory effect of polylysine in smooth muscle is a direct effect on the muscle cell since polylysine attenuated acetylcholine- and adenosine triphosphate-induced contractions in the ileum, and ATP- or noradrenaline-induced contractions in the vas deferens. Pillar structures, believed to be of importance to excitation contraction coupling, were compared. In heart and skeletal muscle the pillars span the gap between sarcoplasmic reticulum and T-tubuli, deeply recessed into the muscle cell. In smooth muscle and outer hair cell the pillars are in closer relation to the cell exterior. The length of the pillars of the outer hair cells exceeds by two times that of smooth and skeletal muscle. The susceptibility of outer hair cells and smooth muscle tissue to the positively charged polylysine may indicate similarities in membrane or channel composition.     

Immunobiosensor analysis- of clenbuterol in bovine hair

Due to the potential speed and flexibility of surface plasmon resonance (SPR)-biosensor analysis, the technique is currently being exploited for detection of residues in food. In the present study an antibody-based inhibition assay for analysis of clenbuterol in cattle hair was developed using a Biacore 2000 instrument. Analysis of clenbuterol with and without enhancement with a secondary antibody was compared. A fast extraction method for hair, which enabled direct analysis in the biosensor with no clean up other than microscale ultrafiltration was developed. In contrast to most of the published methods in the area, no organic solvent or solid phase extraction step was needed. The biosensor method was validated by analysis of hair samples from animals treated with clenbuterol and the results were compared to results from GC-MS analysis. The correlation was good (r ²=92.7%). The detection limit of the new method was 10 ng g^?1 hair.     

Hair sampling for chromium content following Charnley hip arthroplasty.

The chromium content of hair has been studied by neutron activation analysis of samples from 62 patients following a Charnley unilateral or bilateral hip arthroplasty by an artificial joint of stainless steel against polyethylene, inserted three to five years previously. The patients lived in the North Wales area of the British Isles. Hair chromium content was also studied in 51 control subjects of similar age to that of the patients, from the same geographical area and often from the patients' own households. Chromium content was recorded as parts per million (ppm) of hair weighed and analyzed in the state received, without preliminary ashing or chemical "washing" of the samples in the laboratory. Fifty of the 51 control subjects showed less than 2 ppm chromium in hair; one showed 2-5 ppm; none showed more than 5 ppm. Fifty-nine of the 62 patients showed less than 2 ppm chromium in hair; three showed 2-5 ppm; none showed more than 5 ppm. Attention is drawn to certain practical aspects when collecting hair samples for chromium analysis. The use and validity of hair sampling as one method of screening for systemic chromium accumulation following implant surgery is discussed. The method may be a useful adjunct to monitoring of chromium levels in blood samples. In this preliminary study, hair sampling has given no evidence of any major risk of systemic chromium accumulation in patients using a Charnley arthroplasty for periods of up to five years; no conclusion can be made concerning periods longer than this. The findings do not exclude systemic reactions of the hypersensitivity type, since this type of reaction could develop to only small amounts of chromium.     

Osmium tetroxide postfixation in relation to the crosslinkage and spatial organization of stereocilia in the guinea-pig cochlea

Summary Guinea-pig cochleae were fixed in glutaraldehyde, followed by short (30 s), intermediate (3 min) or long (24 h) periods of postfixation in 1% osmium tetroxide. The hair cells of the organ of Corti were examined by scanning electron microscopy. Following short periods of postfixation in osmium tetroxide, the preservation of crosslinks between the stereocilia could be enhanced, compared to the picture seen without postfixation. Moreover, in many cases the stereocilia parted slightly, revealing many lateral links between the stereocilia, which were otherwise hidden. The tip of each shorter stereocilium on a hair cell gave rise to a single, vertically pointing link, which ran upwards to the taller stereocilium of the adjacent row on the hair cell. It is suggested that distortion of such links is associated with sensory transduction. An extensive array of lateral links, connecting the stereocilia of the same and different rows on the hair cell, was also seen. In addition, the surface membranes of the stereocilia had a granular appearance. Following intermediate and long periods of postfixation in osmium tetroxide, crosslinks were rarely seen, and the stereocilia had smooth or wavy rather than granular surface membranes. Moreover, the spatial organization of the stereocilia, particularly on inner hair cells, was disrupted. In tissue postfixed for short periods, it was possible to map the directions of the vertically pointing links, and see the three-dimensional arrangement of the stereocilia. It was shown that the V-shape of the rows of stereocilia on outer hair cells, and the straight-line arrangement of the stereocilia on inner hair cells, were both appropriate for a maximal sensitivity of the hair cells to deflection of their stereocilia in a radial direction. It is suggested that the differences in the shape of the rows on inner and outer hair cells are derived from the different packing of the stereocilia on the two types of hair cell.     

Detection of Fabry''s disease heterozygotes by hair root analysis

The alpha-galactosidase/beta-hexosaminidase ratio was measured for individual hair roots as a method for heterozygote detection in Fabry's disease. Hair root analysis in control individuals revealed no striking sex difference in alpha-galactosidase/beta-hexosaminidase ratio when five males and five females were compared. The values for the ratio X 100, calculating both enzyme activities in nmol of product per min per microliter of hair extract, ranged from 0.8 to 9 for controls and from less than 0.1 to 0.4 for two hemizygous males. Hair root analysis in four heterozygotes with clinical evidence of disease gave values for each individual in the control range, in the range for hemizygotes and in an intermediate range. The experience using hair root analysis for heterozygote detection in the X-linked Lesch-Nyhan syndrome suggests that this approch will be a sensitive heterozygote detection method which takes advantage of the occurrence of hairs with a deficient phenotype on the basis of Lyonization. We observed an affected male who was born to a female without clinical or biochemical evidence (examination included extensive hair root analysis) of Fabry's disease, thus documenting a likely instance of new mutation.     

Use of hair pores to determine the orientation of collagen fibers in skin

Most people are interested in recovery of skin defects caused by burn, scald or trauma from the aesthetic and functional point of view. It will occupy an important role for successful skin graft for patients with such skin defects that the orientation of collagen fibers in the grafted skin matches to the fiber orientation in surrounding skin. There have been, to my best knowledge, no methods for determining the orientation of collagen fibers in the skin from the clinical point of view. Recently, the author has found a new method for directly determining the collagen-fiber orientation without cutting samples from a calf leather by analyzing the anisotropic shape of hair pore. Its principle is based on the quantitative evaluation of collagen-fiber orientation by approximating a hair pore to an ellipse. The results obtained by the new method using hair pores were supported by the microwave method, mechanical measurements and scanning electron microscopy. Such a method will be applicable for determining the orientational distribution of collagen fibers in skins of animals and humans and give a valuable probe for performing skin grafting based on the scientific data of hair pores.     

Recessive metaphyseal dysplasia without hypotrichosis. A syndrome clinically distinct from McKusick cartilage-hair hypoplasia.

Among children with recessive metaphyseal dysplasia involving the knees and extremities, two types can be distinguished. In true cartilage-hair hypoplasia, as described by McKusick, many patients show clinical hair involvement and variable immunodeficiency. We present a series of six patients with the same radiological changes, but without apparent hypotrichosis. We suggest that they should be considered as having a variant form of cartilage-hair hypoplasia, with a clinically distinct phenotype, which could be as common as 'true' cartilage-hair hypoplasia among non-Amish populations. Microscopic examination of the hair may show reduction in the diameter of the hair shaft. This form of metaphyseal dysplasia may result from allelic heterogeneity.     

Human hair is a potential source of cat allergen contamination of ambient air

BACKGROUND: We have previously shown that airborne cat allergen levels are significantly lower in school classes using special school clothing or in classes with no pet owners. However, cat allergen is present and the levels are in fact two- to threefold higher on cat owners' than noncat owners' school clothing which is used, washed and stored at school only. This suggests that allergen is transferred to schools by routes other than clothing. AIM: To analyse levels of cat allergen (Fel d 1) in hair from cat owners and noncat owners among children and adults. METHODS: Samples of unwashed hair (> or =1 day prior to sampling) from adults and children with (n = 22) or without (n = 22) cats at home were collected at a hairdresser. In addition, samples of newly washed hair (adults only, n = 11) were collected. The hair sample was extracted and analysed for Fel d 1 content with ELISA. RESULTS: The geometric mean levels were more than two orders of magnitude higher in unwashed hair from cat owners, compared with noncat owners (P < 0.0001) and more than 10-fold higher in newly washed hair from adults. The allergen contamination of unwashed hair among noncat owners appeared higher in children than in adults (P = 0.045). CONCLUSIONS: Hair may be an important source for transfer and deposition of cat allergen in schools and may explain why cat allergen is found in environments with strict allergen avoidance measures. Although it may be unrealistic to apply allergen avoidance strategies against this allergen source, it is important to be aware of it.     

A comparative study on polychlorinated biphenyls (PCB) and polychlorinated quaterphenyls (PCQ) concentrations in subcutaneous fat tissue, blood and hair of patients with yusho and normal control in Nagasaki prefecture

The relationship between PCB and PCQ concentrations in the blood, subcutaneous fat tissue and hair was investigated in this study. PCB and PCQ concentrations in twenty four patients with PCB poisoning (yusho) and 59 normal controls were analyzed. The alkaline decomposition method described in the official standard analytical methods for the isolation of PCB and PCQ fractions was used. The mean value of PCB concentrations was 2.43 ppb, CB% ratio was 0.69 and the PCQ concentration in the blood of the control group was too low to be detected by our analysis. On the other hand, the PCB concentration and CB% ratio in the yusho group were two times higher than those in the control group. The mean value of PCQ concentration was 1.34 ppb in the yusho group although it was below the level of detection in the control group. The mean PCB concentration in the hair of patients with yusho was 28.92 ppb, and 8.06 ppb in the control group. CB% ratio in the hair of patients with yusho was two times higher than that in the control group. The mean value of PCQ concentration in the hair of patients with yusho was 0.55 ppb although it was not detected in the control group. The PCB and PCQ concentrations in the hair were not greatly elevated when compared with those in the subcutaneous fat tissue. However, the hair is an excellent sample for the detection of these chemicals because it can be collected simply without operation.     

Ability of transplanted cultured epithelium to respond to dermal papillae.

Cultured epithelium has been used successfully in the treatment of extensive burns. Regenerated epidermis, however, lacks such as hair follicles and sweat glands that are common in mammalian skin. We attempted to determine whether cultured epithelium could be induced to form hair follicles by dermal papillae, which are most important for the morphogenesis and growth of hair follicles. We cultivated adult rat sole keratinocytes, obtained the cultured epithelium, and prepared recombinants consisting of cultured epithelium and fresh dermal papillae with or without the sole dermis. These recombinants were then transplanted underneath the dermis of the dorsal skin of syngeneic rats or athymic mice. Histologic examination revealed that the transplanted cultured epithelium formed the follicular structures with sebaceous gland-like structure following induction of the dermal papillae, especially when supported by the dermis. We concluded that transplanted cultured epithelium of adult rat sole keratinocytes can respond to growth signals from adult dermal papillae.