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Sample records for active outer hair

  1. Active Outer Hair Cells Affect the Sound-Evoked Vibration of the Reticular Lamina

    NASA Astrophysics Data System (ADS)

    Jacob, Stefan; Fridberger, Anders

    2011-11-01

    It is well established that the organ of Corti uses active mechanisms to enhance its sensitivity and frequency selectivity. Two possible mechanisms have been identified, both capable of producing mechanical forces, which can alter the sound-evoked vibration of the hearing organ. However, little is known about the effect of these forces on the sound-evoked vibration pattern of the reticular lamina. Current injections into scala media were used to alter the amplitude of the active mechanisms in the apex of the guinea pig temporal bone. We used time-resolved confocal imaging to access the vibration pattern of individual outer hair cells. During positive current injection the the sound-evoked vibration of outer hair cell row three increased while row one showed a small decrease. Negative currents reversed the observed effect. We conclude that the outer hair cell mediated modification of reticular lamina vibration patterns could contribute to the inner hair cell stimulation.

  2. Effects of cochlear loading on the motility of active outer hair cells

    PubMed Central

    Ó Maoiléidigh, Dáibhid; Hudspeth, A. J.

    2013-01-01

    Outer hair cells (OHCs) power the amplification of sound-induced vibrations in the mammalian inner ear through an active process that involves hair-bundle motility and somatic motility. It is unclear, though, how either mechanism can be effective at high frequencies, especially when OHCs are mechanically loaded by other structures in the cochlea. We address this issue by developing a model of an active OHC on the basis of observations from isolated cells, then we use the model to predict the response of an active OHC in the intact cochlea. We find that active hair-bundle motility amplifies the receptor potential that drives somatic motility. Inertial loading of a hair bundle by the tectorial membrane reduces the bundle’s reactive load, allowing the OHC’s active motility to influence the motion of the cochlear partition. The system exhibits enhanced sensitivity and tuning only when it operates near a dynamical instability, a Hopf bifurcation. This analysis clarifies the roles of cochlear structures and shows how the two mechanisms of motility function synergistically to create the cochlear amplifier. The results suggest that somatic motility evolved to enhance a preexisting amplifier based on active hair-bundle motility, thus allowing mammals to hear high-frequency sounds. PMID:23509256

  3. Activity-dependent regulation of prestin expression in mouse outer hair cells

    PubMed Central

    Song, Yohan; Xia, Anping; Lee, Hee Yoon; Wang, Rosalie; Ricci, Anthony J.

    2015-01-01

    Prestin is a membrane protein necessary for outer hair cell (OHC) electromotility and normal hearing. Its regulatory mechanisms are unknown. Several mouse models of hearing loss demonstrate increased prestin, inspiring us to investigate how hearing loss might feedback onto OHCs. To test whether centrally mediated feedback regulates prestin, we developed a novel model of inner hair cell loss. Injection of diphtheria toxin (DT) into adult CBA mice produced significant loss of inner hair cells without affecting OHCs. Thus, DT-injected mice were deaf because they had no afferent auditory input despite OHCs continuing to receive normal auditory mechanical stimulation and having normal function. Patch-clamp experiments demonstrated no change in OHC prestin, indicating that loss of information transfer centrally did not alter prestin expression. To test whether local mechanical feedback regulates prestin, we used TectaC1509G mice, where the tectorial membrane is malformed and only some OHCs are stimulated. OHCs connected to the tectorial membrane had normal prestin levels, whereas OHCs not connected to the tectorial membrane had elevated prestin levels, supporting an activity-dependent model. To test whether the endocochlear potential was necessary for prestin regulation, we studied TectaC1509G mice at different developmental ages. OHCs not connected to the tectorial membrane had lower than normal prestin levels before the onset of the endocochlear potential and higher than normal prestin levels after the onset of the endocochlear potential. Taken together, these data indicate that OHC prestin levels are regulated through local feedback that requires mechanoelectrical transduction currents. This adaptation may serve to compensate for variations in the local mechanical environment. PMID:25810486

  4. Cochlear amplification, outer hair cells and prestin

    PubMed Central

    Dallos, Peter

    2008-01-01

    Mechanical amplification of acoustic signals is apparently a common feature of vertebrate auditory organs. In non-mammalian vertebrates amplification is produced by stereociliary processes, related to the mechanotransducer channel complex and probably to the phenomenon of fast adaptation. The extended frequency range of the mammalian cochlea has likely co-evolved with a novel hair cell type, the outer hair cell and its constituent membrane protein, prestin. Cylindrical outer hair cells are motile and their somatic length changes are voltage driven and powered by prestin. One of the central outstanding problems in mammalian cochlear neurobiology is the relation between the two amplification processes. PMID:18809494

  5. Outer Hair Cell Electromotility and Otoacoustic Emissions*

    PubMed Central

    Brownell, William E.

    2009-01-01

    Outer hair cell electromotility is a rapid, force generating, length change in response to electrical stimulation. DC electrical pulses either elongate or shorten the cell and sinusoidal electrical stimulation results in mechanical oscillations at acoustic frequencies. The mechanism underlying outer hair cell electromotility is thought to be the origin of spontaneous otoacoustic emissions. The ability of the cell to change its length requires that it be mechanically flexible. At the same time the structural integrity of the organ of Corti requires that the cell possess considerable compressive rigidity along its major axis. Evolution appears to have arrived at novel solutions to the mechanical requirements imposed on the outer hair cell. Segregation of cytoskeletal elements in specific intracellular domains facilitates the rapid movements. Compressive strength is provided by a unique hydraulic skeleton in which a positive hydrostatic pressure in the cytoplasm stabilizes a flexible elastic cortex with circumferential tensile strength. Cell turgor is required in order that the pressure gradients associated with the electromotile response can be communicated to the ends of the cell. A loss in turgor leads to loss of outer hair cell electromotility. Concentrations of salicylate equivalent to those that abolish spontaneous otoacoustic emissions in patients weaken the outer hair cell’s hydraulic skeleton. There is a significant diminution in the electromotile response associated with the loss in cell turgor. Aspirin’s effect on outer hair cell electromotility attests to the role of the outer hair cell in generating otoacoustic emissions and demonstrates how their physiology can influence the propagation of otoacoustic emissions. PMID:2187727

  6. Can Outer Hair Cells Actively Pump Fluid into the Tunnel of Corti?

    NASA Astrophysics Data System (ADS)

    Zagadou, Brissi Franck; Mountain, David C.

    2011-11-01

    Non-classical models of the cochlear traveling wave have been introduced in attempt to capture the unique features of the cochlear amplifier (CA). These models include multiple modes of longitudinal coupling. In one approach, it is hypothesized that two wave modes can add their energies to create amplification such as that desired in the CA. The tunnel of Corti (ToC) was later used to represent the second wave mode for the proposed traveling wave amplifier model, and was incorporated in a multi-compartment cochlea model. The results led to the hypothesis that the CA functions as a fluid pump. However, this hypothesis must be consistent with the anatomical structure of the organ of Corti (OC). The fluid must pass between the outer pillar cells before reaching the ToC, and the ToC fluid and the underlying basilar membrane must constitute an appropriate waveguide. We have analyzed an anatomically based 3D finite element model of the ToC of the gerbil. Our results demonstrate that the OC structure is consistent with the hypothesis.

  7. Loss of glycine receptors containing the α3 subunit compromises auditory nerve activity, but not outer hair cell function.

    PubMed

    Dlugaiczyk, Julia; Hecker, Dietmar; Neubert, Christian; Buerbank, Stefanie; Campanelli, Dario; Becker, Cord-Michael; Betz, Heinrich; Knipper, Marlies; Rüttiger, Lukas; Schick, Bernhard

    2016-07-01

    Inhibitory glycine receptors containing the α3 subunit (GlyRα3) regulate sensory information processing in the CNS and retina. In previous work, we demonstrated the presence of postsynaptic GlyRα3 immunoreactivity at efferent synapses of the medial and lateral olivocochlear bundle in the organ of Corti; however, the role of these α3-GlyRs in auditory signalling has remained elusive. The present study analyzes distortion-product otoacoustic emissions (DPOAEs) and auditory brainstem responses (ABRs) of knockout mice with a targeted inactivation of the Glra3 gene (Glra3(-/-)) and their wildtype littermates (Glra3(+/+)) before and seven days after acoustic trauma (AT; 4-16 kHz, 120 dB SPL, 1 h). Before AT, DPOAE thresholds were slightly, but significantly lower, and DPOAE amplitudes were slightly larger in Glra3(-/-) as compared to Glra3(+/+) mice. While click- and f-ABR thresholds were similar in both genotypes before AT, threshold-normalized click-ABR wave I amplitudes were smaller in Glra3(-/-) mice as compared to their wildtype littermates. Following AT, both the decrement of ABR wave I amplitudes and the delay of wave I latencies were more pronounced in Glra3(-/-) than Glra3(+/+) mice. Accordingly, correlation between early click-evoked ABR signals (0-2.5 ms from stimulus onset) before and after AT was significantly reduced for Glra3(-/-) as compared to Glra3(+/+) mice. In summary, these results show that loss of α3-GlyRs compromises suprathreshold auditory nerve activity, but not outer hair cell function. PMID:27208792

  8. Motile responses in outer hair cells.

    PubMed

    Zenner, H P

    1986-01-01

    Motile responses of cochlear hair cells open new perspectives for the understanding of cochlear hearing mechanisms and hearing disorders located in hair cells. Direct visualization of hair cell motility was achieved by a method for the study of living isolated mammalian outer hair cells (OHCs) which has overcome some of the complexities in dealing with the heterogeneous organ of Corti. Electrophysiological giga-seal whole-cell recordings of single OHC prepared by this approach had revealed negative cell potentials ranging from -32 mV to -70 mV (Gitter et al. (1986) Oto-Rhino-Laryngol. in press). Elucidation of HC motility has come from two lines of experiments. One follows from the observation that exposure of the lateral and basal membrane parts of living OHCs to increasing bath K+ concentrations resulted in a sustained reversible depolarization of the cell. Here, we report that by depolarization of the cell membrane in the presence of 25-125 mM K+/Cl- a sustained contraction of OHC was induced. This was followed by relaxation in the presence of artificial perilymph containing 5.4 mM K+/Cl-. By alternating these procedures OHCs were made to undergo as many as five cycles of contraction and relaxation. External Ca2+ was not required for the initial contraction but was essential for relaxation. Following repeated contraction/relaxation cycles the cytoplasm of individual OHCs exhibited a filamentous network, correlating with a new infracuticular anti-actin binding capacity. The second series of experiments originates in the observation that permeabilized OHCs contracted in the presence of ATP. No response was seen in the presence of control nucleotides.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3733547

  9. Outer Hair Cell Electromotility in vivo

    NASA Astrophysics Data System (ADS)

    Ramamoorthy, Sripriya; Nuttall, Alfred L.

    2011-11-01

    The effectiveness of outer hair cell (OHC) electro-motility in vivo has been challenged by the expected low-pass filtering of the transmembrane potential due to the cell's own capacitance. The OHC electromotility is characterized here by an electromechanical ratio defined as the ratio of the OHC contraction to the transmembrane potential. This ratio has been measured in isolated cells to be approximately 26 nm/mV. We estimate the OHC electromechanical ratio in vivo from the recently measured displacements of the reticular lamina and the basilar membrane near the 19 kHz characteristic frequency in the basal region of guinea pig cochlea. Our analysis strongly suggests OHC electromotility process is effective for cochlear amplification in vivo at least around the characteristic frequency of the basal location in spite of the low-pass filtering.

  10. Optogenetic Control of Mouse Outer Hair Cells.

    PubMed

    Wu, Tao; Ramamoorthy, Sripriya; Wilson, Teresa; Chen, Fangyi; Porsov, Edward; Subhash, Hrebesh; Foster, Sarah; Zhang, Yuan; Omelchenko, Irina; Bateschell, Michael; Wang, Lingyan; Brigande, John V; Jiang, Zhi-Gen; Mao, Tianyi; Nuttall, Alfred L

    2016-01-19

    Normal hearing in mammals depends on sound amplification by outer hair cells (OHCs) presumably by their somatic motility and force production. However, the role of OHC force production in cochlear amplification and frequency tuning are not yet fully understood. Currently, available OHC manipulation techniques for physiological or clinical studies are limited by their invasive nature, lack of precision, and poor temporal-spatial resolution. To overcome these limitations, we explored an optogenetic approach based on channelrhodopsin 2 (ChR-2), a direct light-activated nonselective cation channel originally discovered in Chlamydomonas reinhardtii. Three approaches were compared: 1) adeno-associated virus-mediated in utero transfer of the ChR-2 gene into the developing murine otocyst, 2) expression of ChR-2(H134R) in an auditory cell line (HEI-OC1), and 3) expression of ChR-2 in the OHCs of a mouse line carrying a ChR-2 conditional allele. Whole cell recording showed that blue light (470 nm) elicited the typical nonselective cation current of ChR-2 with reversal potential around zero in both mouse OHCs and HEI-OC1 cells and generated depolarization in both cell types. In addition, pulsed light stimulation (10 Hz) elicited a 1:1 repetitive depolarization and ChR-2 currents in mouse OHCs and HEI-OC1 cells, respectively. The time constant of depolarization in OHCs, 1.45 ms, is 10 times faster than HEI-OC1 cells, which allowed light stimulation up to rates of 10/s to elicit corresponding membrane potential changes. Our study demonstrates that ChR-2 can successfully be expressed in mouse OHCs and HEI-OC1 cells and that these present a typical light-sensitive current and depolarization. However, the amount of ChR-2 current induced in our in vivo experiments was insufficient to result in measurable cochlear effects. PMID:26789771

  11. Decreasing Outer Hair Cell Membrane Cholesterol Increases Cochlear Electromechanics

    NASA Astrophysics Data System (ADS)

    Brownell, William E.; Jacob, Stefan; Hakizimana, Pierre; Ulfendahl, Mats; Fridberger, Anders

    2011-11-01

    The effect of decreasing membrane cholesterol on the mechanical response of the cochlea to acoustic and/or electrical stimulation was monitored using laser interferometry. In contrast to pharmacological interventions that typically decrease cochlear electromechanics, reducing membrane cholesterol increased the response. The electromechanical response in untreated preparations was asymmetric with greater displacements in response to positive currents and cholesterol depletion increased the asymmetry. The results confirm that outer hair cell electromotility is enhanced by low membrane cholesterol. The asymmetry of the response indicates the outer hair cell resting membrane potential is hyperpolarized relative to the voltage of maximum gain for the outer hair cell voltage-displacement function. The magnitude of the response increase suggests a non-uniform distribution of cholesterol along the lateral wall of normal adult outer hair cells.

  12. Characterization of transcriptomes of cochlear inner and outer hair cells.

    PubMed

    Liu, Huizhan; Pecka, Jason L; Zhang, Qian; Soukup, Garrett A; Beisel, Kirk W; He, David Z Z

    2014-08-13

    Inner hair cells (IHCs) and outer hair cells (OHCs) are the two types of sensory receptor cells that are critical for hearing in the mammalian cochlea. IHCs and OHCs have different morphology and function. The genetic mechanisms that define their morphological and functional specializations are essentially unknown. The transcriptome reflects the genes that are being actively expressed in a cell and holds the key to understanding the molecular mechanisms of the biological properties of the cell. Using DNA microarray, we examined the transcriptome of 2000 individually collected IHCs and OHCs from adult mouse cochleae. We show that 16,647 and 17,711 transcripts are expressed in IHCs and OHCs, respectively. Of those genes, ∼73% are known genes, 22% are uncharacterized sequences, and 5.0% are noncoding RNAs in both populations. A total of 16,117 transcripts are expressed in both populations. Uniquely and differentially expressed genes account for <15% of all genes in either cell type. The top 10 differentially expressed genes include Slc17a8, Dnajc5b, Slc1a3, Atp2a3, Osbpl6, Slc7a14, Bcl2, Bin1, Prkd1, and Map4k4 in IHCs and Slc26a5, C1ql1, Strc, Dnm3, Plbd1, Lbh, Olfm1, Plce1, Tectb, and Ankrd22 in OHCs. We analyzed commonly and differentially expressed genes with the focus on genes related to hair cell specializations in the apical, basolateral, and synaptic membranes. Eighty-three percent of the known deafness-related genes are expressed in hair cells. We also analyzed genes involved in cell-cycle regulation. Our dataset holds an extraordinary trove of information about the molecular mechanisms underlying hair cell morphology, function, pathology, and cell-cycle control. PMID:25122905

  13. Power Efficiency of Outer Hair Cell Somatic Electromotility

    PubMed Central

    Rabbitt, Richard D.; Clifford, Sarah; Breneman, Kathryn D.; Farrell, Brenda; Brownell, William E.

    2009-01-01

    Cochlear outer hair cells (OHCs) are fast biological motors that serve to enhance the vibration of the organ of Corti and increase the sensitivity of the inner ear to sound. Exactly how OHCs produce useful mechanical power at auditory frequencies, given their intrinsic biophysical properties, has been a subject of considerable debate. To address this we formulated a mathematical model of the OHC based on first principles and analyzed the power conversion efficiency in the frequency domain. The model includes a mixture-composite constitutive model of the active lateral wall and spatially distributed electro-mechanical fields. The analysis predicts that: 1) the peak power efficiency is likely to be tuned to a specific frequency, dependent upon OHC length, and this tuning may contribute to the place principle and frequency selectivity in the cochlea; 2) the OHC power output can be detuned and attenuated by increasing the basal conductance of the cell, a parameter likely controlled by the brain via the efferent system; and 3) power output efficiency is limited by mechanical properties of the load, thus suggesting that impedance of the organ of Corti may be matched regionally to the OHC. The high power efficiency, tuning, and efferent control of outer hair cells are the direct result of biophysical properties of the cells, thus providing the physical basis for the remarkable sensitivity and selectivity of hearing. PMID:19629162

  14. Activation of BK and SK channels by efferent synapses on outer hair cells in high-frequency regions of the rodent cochlea.

    PubMed

    Rohmann, Kevin N; Wersinger, Eric; Braude, Jeremy P; Pyott, Sonja J; Fuchs, Paul Albert

    2015-02-01

    Cholinergic neurons of the brainstem olivary complex project to and inhibit outer hair cells (OHCs), refining acoustic sensitivity of the mammalian cochlea. In all vertebrate hair cells studied to date, cholinergic inhibition results from the combined action of ionotropic acetylcholine receptors and associated calcium-activated potassium channels. Although inhibition was thought to involve exclusively small conductance (SK potassium channels), recent findings have shown that BK channels also contribute to inhibition in basal, high-frequency OHCs after the onset of hearing. Here we show that the waveform of randomly timed IPSCs (evoked by high extracellular potassium) in high-frequency OHCs is altered by blockade of either SK or BK channels, with BK channels supporting faster synaptic waveforms and SK channels supporting slower synaptic waveforms. Consistent with these findings, IPSCs recorded from high-frequency OHCs that express BK channels are briefer than IPSCs recorded from low-frequency (apical) OHCs that do not express BK channels and from immature high-frequency OHCs before the developmental onset of BK channel expression. Likewise, OHCs of BKα(-/-) mice lacking the pore-forming α-subunit of BK channels have longer IPSCs than do the OHCs of BKα(+/+) littermates. Furthermore, serial reconstruction of electron micrographs showed that postsynaptic cisterns of BKα(-/-) OHCs were smaller than those of BKα(+/+) OHCs, and immunofluorescent quantification showed that efferent presynaptic terminals of BKα(-/-) OHCs were smaller than those of BKα(+/+) OHCs. Together, these findings indicate that BK channels contribute to postsynaptic function, and influence the structural maturation of efferent-OHC synapses. PMID:25653344

  15. Modulation by purines of calcium-activated non-selective cation channels in the outer hair cells of the guinea-pig cochlea.

    PubMed Central

    Van den Abbeele, T; Tran Ba Huy, P; Teulon, J

    1996-01-01

    1. The cell-attached and cell-free configurations of the patch-clamp technique were used to investigate whether external ATP and its derivatives modulate channel activity in outer hair cells freshly isolated from the guinea-pig cochlea. 2. Submicromolar concentrations of ATP stimulated a non-selective cation channel with a conductance of about 25 pS. The ATP-elicited stimulation was partly blocked by the membrane-permeant blocker 3',5-dichlorodiphenylamine-2-carboxylic acid (DCDPC), and mimicked by the calcium ionophore, ionomycin, suggesting that the channel activated by ATP is identical to a previously reported calcium-activated non-selective (CAN) cation channel. 3. The P2x agonist beta, gamma-methylene-ATP (beta, gamma-MeATP, 10 microM) and the P2Y agonist 2-methyl-thio-ATP (2-MeSATP, 1 microM) both activated CAN channels. The effect of ATP was inhibited by the P2 antagonist suramin but not by the P2Y antagonist Reactive Blue 2. These results suggest that both purinergic receptors are involved in the ATP-evoked response and that internal calcium acts as a second messenger for opening CAN channels. 4. In contrast, adenosine inhibited CAN channels. This effect was reproduced by the A2 agonist 5'-N-ethylcarboxyamidoadenosine (NECA) and the permeant cAMP analogue 8-bromo-adenosine 3',5'-cyclic monophosphate (8-Br-cAMP), but not by the A1 agonist N6-cyclo-hexyladenosine (CHA). CAN channels were also inhibited when the catalytic subunit of protein kinase A was applied internally on inside-out patches, suggesting that adenosine A2 receptor downregulates CAN channels via a cAMP-dependent phosphorylation. Images Figure 10 PMID:8814608

  16. Outer hair cells as potential targets of inflammatory mediators.

    PubMed

    Huang, M; Dulon, D; Schacht, J

    1990-06-01

    Inner ear sequelae with temporary or permanent sensorineural hearing loss can result from inflammatory processes in the middle ear. Loss of outer hair cells in the base of the cochlea has been noted in otitis media, but it is not known how this damage occurs. Evidence supports the permeability of the round window membrane to substances mediating inflammation in the middle ear, and the presence of white blood cells has been reported in the perilymph. In the present study, the potential cytotoxic effects of two representative inflammatory mediators, endotoxin and free radicals, have been evaluated by use of short-term culture of isolated outer hair cells from the guinea pig cochlea model. Incubation with endotoxins from two gram-negative pathogens increased the rate of hair cell death fourfold to sixfold. Free radicals (generated by exposure of cells to UV light or by excitation of intracellular fluorescent dyes) produced morphologic damage to hair cells within 60 seconds. These latter effects were delayed by addition of free-radical scavengers. It is concluded that inflammatory mediators are cytotoxic to hair cells and therefore are potentially ototoxic if permeating the round window membrane. PMID:2112361

  17. Direct immunofluorescence of the outer root sheath in anagen and telogen hair in pemphigus vulgaris and pemphigus foliaceus.

    PubMed

    Tanasilovic, Srdjan; Medenica, Ljiljana; Popadic, Svetlana

    2014-11-01

    Direct immunofluorescence of peri-lesional skin is the gold standard in the diagnosis of pemphigus. A specific immunofluorescence pattern may also be demonstrated in the outer root sheath of anagen and telogen hair. We demonstrated an intercellular reticular deposition of immunoglobulin G in the outer root sheath of plucked anagen and telogen hair in all pemphigus vulgaris patients with active disease and for the first time in all patients with active pemphigus foliaceus. Moreover, we demonstrated for the first time that plucked hair samples may be kept at -20°C for at least 2 weeks before immunofluorescent staining and analysis. PMID:23713982

  18. Sound-induced length changes in outer hair cell stereocilia

    PubMed Central

    Hakizimana, Pierre; Brownell, William E.; Jacob, Stefan

    2013-01-01

    Hearing relies on mechanical stimulation of stereocilia bundles on the sensory cells of the inner ear. When sound hits the ear, these stereocilia pivot about a neck-like taper near their base. More than three decades of research have established that sideways deflection of stereocilia is essential for converting mechanical stimuli into electrical signals. Here we show that mammalian outer hair cell stereocilia not only move sideways but also change length during sound stimulation. Currents that enter stereocilia through mechanically sensitive ion channels control the magnitude of both length changes and bundle deflections in a reciprocal manner: the smaller the length change, the larger is the bundle deflection. Thus, the transduction current is important for maintaining the resting mechanical properties of stereocilia. Hair cell stimulation is most effective when bundles are in a state that ensures minimal length change. PMID:23033070

  19. Sound-induced length changes in outer hair cell stereocilia.

    PubMed

    Hakizimana, Pierre; Brownell, William E; Jacob, Stefan; Fridberger, Anders

    2012-01-01

    Hearing relies on mechanical stimulation of stereocilia bundles on the sensory cells of the inner ear. When sound hits the ear, each stereocilium pivots about a neck-like taper near their base. More than three decades of research have established that sideways deflection of stereocilia is essential for converting mechanical stimuli into electrical signals. Here we show that mammalian outer hair cell stereocilia not only move sideways but also change length during sound stimulation. Currents that enter stereocilia through mechanically sensitive ion channels control the magnitude of both length changes and bundle deflections in a reciprocal manner: the smaller the length change, the larger is the bundle deflection. Thus, the transduction current is important for maintaining the resting mechanical properties of stereocilia. Hair cell stimulation is most effective when bundles are in a state that ensures minimal length change. PMID:23033070

  20. [High resolution scanning electron microscopy of isolated outer hair cells].

    PubMed

    Koitschev, A; Müller, H

    1996-11-01

    Isolated hair cell preparations have gained wide acceptance as a model for studying physiological and molecular properties of the sensory cells involved in the hearing process. Ultrastructural details, such as stereocilia links, lateral membrane substructure or synaptic links are of crucial importance for normal sensory transduction. For this reason, we developed a high-resolution scanning electron microscopy (SEM) procedure to study the surface of isolated hair cells. Cells were mechanically and/or enzymatically separated, isolated and immobilized on cover slips by alcian blue and fixed by 2% glutardialdehyde or 1% OsO4. After dehydration, preparations were critical point-dried and sputter-coated with gold-palladium (2-4 nm). Up to 5 nm resolution was achieved. Optimal fixation kept the cells in their typical cylindrical forms. Preservation of the stereocilia and the apical plates of the outer hair cells depended strongly on the fixation process. Tip- and side-links were observed only sporadically because of the aggressive preparation procedure. The lateral plasma membranes of the cell bodies showed regular granular structures of 5-7 nm diameter at maximal magnification. The granular structure of the cell membrane seemed to correspond to putative transmembrane proteins believed to generate membrane-based motility. The remnants of the nerve endings and/or supporting cells usually covered the cell base. The preservation of the cells was better when enzymatic isolation was omitted. The technique used allowed for high resolution ultrastructural examination of isolated hair cells and, when combined with immunological labeling, may permit the identification of proteins at a molecular level. PMID:9064297

  1. Cholinergic inhibition of short (outer) hair cells of the chick's cochlea.

    PubMed

    Fuchs, P A; Murrow, B W

    1992-03-01

    Cochlear hair cells are thought to be inhibited by the release of ACh from efferent neurons. Several studies have implicated Ca2+ as a postsynaptic intermediary in hair cell inhibition, but its role remains unproven. We have made whole-cell, tight-seal recordings from single short hair cells (the avian analog of outer hair cells in the mammalian cochlea), isolated from the chick's cochlea, to determine the mechanism of cholinergic inhibition. These cells hyperpolarized upon exposure to ACh, although a brief depolarization preceded the much larger, longer-lasting hyperpolarization. In voltage clamp ACh evoked an outward current that reversed in sign near the K+ equilibrium potential. A small, transient inward current preceded the predominant outward current. The ACh-evoked K+ current depended on Ca2+ in the external saline, or could be prevented when the cell was dialyzed with the rapid Ca2+ buffer BAPTA. In BAPTA-loaded cells a residual inward current was seen. This activated with very little delay upon exposure of the cell to ACh and reversed near 0 mV membrane potential. Thus, the hair cell ACh receptor appears to be a nonspecific cation channel through which Ca2+ enters and triggers the opening of nearby Ca(2+)-activated K+ channels. However, the ACh-evoked K+ channels are not the same as the "maxi" K+ channels activated by Ca2+ influx through voltage-gated Ca2+ channels in these same cells. PMID:1545240

  2. Membrane tether formation from voltage-clamped outer hair cells using optical tweezers

    NASA Astrophysics Data System (ADS)

    Qian, Feng; Ermilov, Sergey A.; Murdock, David R.; Brownell, William E.; Anvari, Bahman

    2004-06-01

    Outer hair cells contribute an active mechanical feedback to the vibrations of the cochlear structures resulting in the high sensitivity and frequency selectivity of normal hearing. We have designed and implemented a novel experimental setup that combines optical tweezers with patch-clamp apparatus to investigate the electromechanical properties of cellular plasma membranes. A micron-size bead trapped by the optical tweezers is brought in contact with the membrane of a voltage-clamped cell, and subsequently moved away to form a plasma membrane tether. Bead displacement during tether elongation is monitored by a quadrant photodetector to obtain time-resolved measurements of the tethering force. Salient information associated with the mechanical properties of the membrane tether can thus be obtained. Tethers can be pulled from the cell membrane at different holding potentials, and the tether force response can be measured while changing transmembrane potential. Experimental results from outer hair cells and human embryonic kidney cells are presented.

  3. Sensory Transduction and Adaptation in Inner and Outer Hair Cells of the Mouse Auditory System

    PubMed Central

    Stauffer, Eric A.; Holt, Jeffrey R.

    2009-01-01

    Auditory function in the mammalian inner ear is optimized by collaboration of two classes of sensory cells known as inner and outer hair cells. Outer hair cells amplify and tune sound stimuli that are transduced and transmitted by inner hair cells. Although they subserve distinct functions, they share a number of common properties. Here we compare the properties of mechanotransduction and adaptation recorded from inner and outer hair cells of the postnatal mouse cochlea. Rapid outer hair bundle deflections of about 0.5 micron evoked average maximal transduction currents of about 325 pA, whereas inner hair bundle deflections of about 0.9 micron were required to evoke average maximal currents of about 310 pA. The similar amplitude was surprising given the difference in the number of stereocilia, 81 for outer hair cells and 48 for inner hair cells, but may be reconciled by the difference in single-channel conductance. Step deflections of inner and outer hair bundles evoked adaptation that had two components: a fast component that consisted of about 60% of the response occurred over the first few milliseconds and a slow component that consisted of about 40% of the response followed over the subsequent 20 –50 ms. The rate of the slow component in both inner and outer hair cells was similar to the rate of slow adaptation in vestibular hair cells. The rate of the fast component was similar to that of auditory hair cells in other organisms and several properties were consistent with a model that proposes calcium-dependent release of tension allows transduction channel closure. PMID:17942617

  4. Active hair-bundle movements can amplify a hair cell’s response to oscillatory mechanical stimuli

    PubMed Central

    Martin, Pascal; Hudspeth, A. J.

    1999-01-01

    To enhance their mechanical sensitivity and frequency selectivity, hair cells amplify the mechanical stimuli to which they respond. Although cell-body contractions of outer hair cells are thought to mediate the active process in the mammalian cochlea, vertebrates without outer hair cells display highly sensitive, sharply tuned hearing and spontaneous otoacoustic emissions. In these animals the amplifier must reside elsewhere. We report physiological evidence that amplification can stem from active movement of the hair bundle, the hair cell’s mechanosensitive organelle. We performed experiments on hair cells from the sacculus of the bullfrog. Using a two-compartment recording chamber that permits exposure of the hair cell’s apical and basolateral surfaces to different solutions, we examined active hair-bundle motion in circumstances similar to those in vivo. When the apical surface was bathed in artificial endolymph, many hair bundles exhibited spontaneous oscillations of amplitudes as great as 50 nm and frequencies in the range 5 to 40 Hz. We stimulated hair bundles with a flexible glass probe and recorded their mechanical responses with a photometric system. When the stimulus frequency lay within a band enclosing a hair cell’s frequency of spontaneous oscillation, mechanical stimuli as small as ±5 nm entrained the hair-bundle oscillations. For small stimuli, the bundle movement was larger than the stimulus. Because the energy dissipated by viscous drag exceeded the work provided by the stimulus probe, the hair bundles powered their motion and therefore amplified it. PMID:10588701

  5. Loss of function of Ywhah in mice induces deafness and cochlear outer hair cells' degeneration

    PubMed Central

    Buret, L; Rebillard, G; Brun, E; Angebault, C; Pequignot, M; Lenoir, M; Do-cruzeiro, M; Tournier, E; Cornille, K; Saleur, A; Gueguen, N; Reynier, P; Amati-Bonneau, P; Barakat, A; Blanchet, C; Chinnery, P; Yu-Wai-Man, P; Kaplan, J; Roux, A-F; Van Camp, G; Wissinger, B; Boespflug-Tanguy, O; Giraudet, F; Puel, J-L; Lenaers, G; Hamel, C; Delprat, B; Delettre, C

    2016-01-01

    In vertebrates, 14-3-3 proteins form a family of seven highly conserved isoforms with chaperone activity, which bind phosphorylated substrates mostly involved in regulatory and checkpoint pathways. 14-3-3 proteins are the most abundant protein in the brain and are abundantly found in the cerebrospinal fluid in neurodegenerative diseases, suggesting a critical role in neuron physiology and death. Here we show that 14-3-3eta-deficient mice displayed auditory impairment accompanied by cochlear hair cells' degeneration. We show that 14-3-3eta is highly expressed in the outer and inner hair cells, spiral ganglion neurons of cochlea and retinal ganglion cells. Screening of YWHAH, the gene encoding the 14-3-3eta isoform, in non-syndromic and syndromic deafness, revealed seven non-synonymous variants never reported before. Among them, two were predicted to be damaging in families with syndromic deafness. In vitro, variants of YWHAH induce mild mitochondrial fragmentation and severe susceptibility to apoptosis, in agreement with a reduced capacity of mutated 14-3-3eta to bind the pro-apoptotic Bad protein. This study demonstrates that YWHAH variants can have a substantial effect on 14-3-3eta function and that 14-3-3eta could be a critical factor in the survival of outer hair cells. PMID:27275396

  6. Piezo1 haploinsufficiency does not alter mechanotransduction in mouse cochlear outer hair cells.

    PubMed

    Corns, Laura F; Marcotti, Walter

    2016-02-01

    The mechanoelectrical transducer (MET) channels located at the stereocilia tip of cochlear hair cells are crucial to convert the mechanical energy of sound into receptor potentials, but the identity of its pore-forming subunits remains uncertain. Piezo1, which has been identified in the transcriptome of mammalian cochlear hair cells, encodes a transmembrane protein that forms mechanosensitive channels in other tissues. We investigated the properties of the MET channel in outer hair cells (OHCs) of Piezo1 mice (postnatal day 6-9). The MET current was elicited by deflecting the hair bundle of OHCs using sinewave and step stimuli from a piezo-driven fluid jet. Apical and basal OHCs were investigated because the properties of the MET channel vary along the cochlea. We found that the maximal MET current amplitude and the resting open probability of the MET channel in OHCs were similar between Piezo1(+/-) haploinsufficient mice and wild-type littermates. The sensitivity to block by the permeant MET channel blocker dihydrostreptomycin was also similar between the two genotypes. Finally, the anomalous mechano-gated current, which is activated by sheer force and which is tip-link independent, was unaffected in OHCs from Piezo1(+/-) haploinsufficient mice. Our results suggest that Piezo1 is unlikely to be a component of the MET channel complex in mammalian cochlear OHCs. PMID:26869684

  7. Fast adaptation and Ca2+-sensitivity of the mechanotransducer require myosin-XVa in inner but not outer cochlear hair cells

    PubMed Central

    Stepanyan, Ruben; Frolenkov, Gregory I.

    2009-01-01

    In inner ear hair cells, activation of mechotransduction channels is followed by extremely rapid deactivation that depends on the influx of Ca2+ through these channels. Although the molecular mechanisms of this “fast” adaptation are largely unknown, the predominant models assume Ca2+ sensitivity as an intrinsic property of yet unidentified mechanotransduction channels. Here we examined mechanotransduction in the hair cells of young postnatal shaker 2 mice (Myo15sh2/sh2). These mice have no functional myosin-XVa, which is critical for normal growth of mechanosensory stereocilia of hair cells. Although stereocilia of both inner and outer hair cells of Myo15sh2/sh2 mice lack myosin-XVa and are abnormally short, these cells have dramatically different hair bundle morphology. Myo15sh2/sh2 outer hair cells retain a “staircase” arrangement of the abnormally short stereocilia and prominent tip links. Myo15sh2/sh2 inner hair cells do not have obliquely oriented tip links and their mechanosensitivity is mediated exclusively by “top-to-top” links between equally short stereocilia. In both inner and outer hair cells of Myo15sh2/sh2 mice, we found mechanotransduction responses with a normal “wild type” amplitude and speed of activation. Surprisingly, only outer hair cells exhibit fast adaptation and sensitivity to extracellular Ca2+. In Myo15sh2/sh2 inner hair cells, fast adaptation is disrupted and the transduction current is insensitive to extracellular Ca2+. We conclude that the Ca2+-sensitivity of the mechanotransduction channels and the fast adaptation require a structural environment that is dependent on myosin-XVa and is disrupted in Myo15sh2/sh2 inner hair cells, but not in Myo15sh2/sh2 outer hair cells. PMID:19339598

  8. Photometric recording of transmembrane potential in outer hair cells

    NASA Astrophysics Data System (ADS)

    Nakagawa, Takashi; Oghalai, John S.; Saggau, Peter; Rabbitt, Richard D.; Brownell, William E.

    2006-06-01

    Cochlear outer hair cells (OHCs) are polarized epithelial cells that have mechanoelectrical transduction channels within their apical stereocilia and produce electromotile force along their lateral wall. Phase shifts, or time delays, in the transmembrane voltage occurring at different axial locations along the cell may contribute to our understanding of how these cells operate at auditory frequencies. We developed a method to optically measure the phase of the OHC transmembrane potential using the voltage-sensitive dye (VSD) di-8-ANEPPS. The exit aperture of a fibre-optic light source was driven in two dimensions so that a 24 µm spot of excitation light could be positioned along the length of the OHC. We used the whole-cell patch-clamp technique in the current-clamp mode to stimulate the OHC at the base. The photometric response and the voltage response were monitored with a photodetector and patch-clamp amplifier, respectively. The photometric response was used to measure the regional changes in the membrane potential in response to maintained (dc) and sinusoidal (ac) current stimuli applied at the base of the cell. We used a neutral density filter to lower the excitation light intensity and reduce phototoxicity. A sensitive detector and lock-in amplifier were used to measure the small ac VSD signal. This permitted measurements of the ac photometric response below the noise floor of the static fluorescence. The amplitude and phase components of the photometric response were recorded for stimuli up to 800 Hz. VSD data at 400-800 Hz show the presence of a small phase delay between the stimulus voltage at the base of the cell and the local membrane potential measured along the lateral wall. Results are consistent with the hypothesis that OHCs exhibit inhomogeneous membrane potentials that vary with position in analogy with the voltage in nerve axons.

  9. Photometric recording of transmembrane potential in outer hair cells

    PubMed Central

    Nakagawa, Takashi; Oghalai, John S; Saggau, Peter; Rabbitt, Richard D; Brownell, William E

    2008-01-01

    Cochlear outer hair cells (OHCs) are polarized epithelial cells that have mechanoelectrical transduction channels within their apical stereocilia and produce electromotile force along their lateral wall. Phase shifts, or time delays, in the transmembrane voltage occurring at different axial locations along the cell may contribute to our understanding of how these cells operate at auditory frequencies. We developed a method to optically measure the phase of the OHC transmembrane potential using the voltage-sensitive dye (VSD) di-8-ANEPPS. The exit aperture of a fibre-optic light source was driven in two dimensions so that a 24 μm spot of excitation light could be positioned along the length of the OHC. We used the whole-cell patch-clamp technique in the current-clamp mode to stimulate the OHC at the base. The photometric response and the voltage response were monitored with a photodetector and patch-clamp amplifier, respectively. The photometric response was used to measure the regional changes in the membrane potential in response to maintained (dc) and sinusoidal (ac) current stimuli applied at the base of the cell. We used a neutral density filter to lower the excitation light intensity and reduce phototoxicity. A sensitive detector and lock-in amplifier were used to measure the small ac VSD signal. This permitted measurements of the ac photometric response below the noise floor of the static fluorescence. The amplitude and phase components of the photometric response were recorded for stimuli up to 800 Hz. VSD data at 400–800 Hz show the presence of a small phase delay between the stimulus voltage at the base of the cell and the local membrane potential measured along the lateral wall. Results are consistent with the hypothesis that OHCs exhibit inhomogeneous membrane potentials that vary with position in analogy with the voltage in nerve axons. PMID:16705263

  10. Hypotonic swelling of salicylate-treated cochlear outer hair cells.

    PubMed

    Zhi, Man; Ratnanather, J Tilak; Ceyhan, Elvan; Popel, Aleksander S; Brownell, William E

    2007-06-01

    The outer hair cell (OHC) is a hydrostat with a low hydraulic conductivity of Pf=3x10(-4) cm/s across the plasma membrane (PM) and subsurface cisterna that make up the OHC's lateral wall. The SSC is structurally and functionally a transport barrier in normal cells that is known to be disrupted by salicylate. The effect of sodium salicylate on Pf is determined from osmotic experiments in which isolated, control and salicylate-treated OHCs were exposed to hypotonic solutions in a constant flow chamber. The value of Pf=3.5+/-0.5x10(-4) cm/s (mean+/-s.e.m., n=34) for salicylate-treated OHCs was not significantly different from Pf=2.4+/-0.3x10(-4) cm/s (mean+/-s.e.m., n=31) for untreated OHCs (p=.3302). Thus Pf is determined by the PM and is unaffected by salicylate treatment. The ratio of longitudinal strain to radial strain epsilonz/epsilonc=-0.76 for salicylate-treated OHCs was significantly smaller (p=.0143) from -0.72 for untreated OHCs, and is also independent of the magnitude of the applied osmotic challenge. Salicylate-treated OHCs took longer to attain a steady-state volume which is larger than that for untreated OHCs and increased in volume by 8-15% prior to hypotonic perfusion unlike sodium alpha-ketoglutarate-treated OHCs. It is suggested that depolymerization of cytoskeletal proteins and/or glycogen may be responsible for the large volume increase in salicylate-treated OHCs as well as the different responses to different modes of application of the hypotonic solution. PMID:17400411

  11. The potential and electric field in the cochlear outer hair cell membrane

    PubMed Central

    Harland, Ben; Lee, Wen-han; Brownell, William E.; Sun, Sean X.; Spector, Alexander A.

    2015-01-01

    Outer hair cell electromechanics, critically important to mammalian active hearing, is driven by the cell membrane potential. The membrane protein prestin is a crucial component of the active outer hair cell’s motor. The focus of the paper is the analysis of the local membrane potential and electric field resulting from the interaction of electric charges involved. Here the relevant charges are the ions inside and outside the cell, lipid bilayer charges, and prestin-associated charges (mobile-transferred by the protein under the action of the applied field and stationary-relatively unmoved by the field). The electric potentials across and along the membrane are computed for the case of an applied DC-field. The local amplitudes and phases of the potential under different frequencies are analyzed for the case of a DC+AC-field. We found that the effect of the system of charges alters the electric potential and internal field, which deviate significantly from their traditional linear and constant distributions. Under DC+AC conditions, the strong frequency dependence of the prestin mobile charge has a relatively small effect on the amplitude and phase of the resulting potential. The obtained results can help in a better understanding and experimental verification of the mechanism of prestin performance. PMID:25687712

  12. Calmodulin-dependent protein kinases mediate calcium-induced slow motility of mammalian outer hair cells.

    PubMed

    Puschner, B; Schacht, J

    1997-08-01

    Cochlear outer hair cells in vitro respond to elevation of intracellular calcium with slow shape changes over seconds to minutes ('slow motility'). This process is blocked by general calmodulin antagonists suggesting the participation of calcium/calmodulin-dependent enzymatic reactions. The present study proposes a mechanism for these reactions. Length changes of outer hair cells isolated from the guinea pig cochlea were induced by exposure to the calcium ionophore ionomycin. ATP levels remained unaffected by this treatment ruling out depletion of ATP (by activation of calcium-dependent ATPases) as a cause of the observed shape changes. Involvement of protein kinases was suggested by the inhibition of shape changes by K252a, a broad-spectrum inhibitor of protein kinase activity. Furthermore, the inhibitors ML-7 and ML-9 blocked the shape changes at concentrations compatible with inhibition of myosin light chain kinase (MLCK). KN-62, an inhibitor of Ca2+/calmodulin-dependent protein kinase II (CaMKII), also attenuated the length changes. Inhibitors with selectivity for cyclic nucleotide-dependent protein kinases (H-89, staurosporine) were tested to assess potential additional contributions by such enzymes. The dose dependence of their action supported the notion that the most likely mechanism of slow motility involves phosphorylation reactions catalyzed by MLCK or CaMKII or both. PMID:9282907

  13. The potential and electric field in the cochlear outer hair cell membrane.

    PubMed

    Harland, Ben; Lee, Wen-han; Brownell, William E; Sun, Sean X; Spector, Alexander A

    2015-05-01

    Outer hair cell electromechanics, critically important to mammalian active hearing, is driven by the cell membrane potential. The membrane protein prestin is a crucial component of the active outer hair cell's motor. The focus of the paper is the analysis of the local membrane potential and electric field resulting from the interaction of electric charges involved. Here the relevant charges are the ions inside and outside the cell, lipid bilayer charges, and prestin-associated charges (mobile-transferred by the protein under the action of the applied field, and stationary-relatively unmoved by the field). The electric potentials across and along the membrane are computed for the case of an applied DC-field. The local amplitudes and phases of the potential under different frequencies are analyzed for the case of a DC + AC-field. We found that the effect of the system of charges alters the electric potential and internal field, which deviate significantly from their traditional linear and constant distributions. Under DC + AC conditions, the strong frequency dependence of the prestin mobile charge has a relatively small effect on the amplitude and phase of the resulting potential. The obtained results can help in a better understanding and experimental verification of the mechanism of prestin performance. PMID:25687712

  14. Membrane recycling at the infranuclear pole of the outer hair cell

    NASA Astrophysics Data System (ADS)

    Harasztosi, Csaba; Harasztosi, Emese; Gummer, Anthony W.

    2015-12-01

    Rapid endocytic activity of outer hair cells (OHCs) in the guinea-pig cochlea has been already studied using the fluorescent membrane marker FM1-43. It was demonstrated that vesicles were endocytosed at the apical pole of OHCs and transcytosed to the basolateral membrane and through a central strand towards the nucleus. The significance of endocytic activity in the infranuclear region is still not clear. Therefore, in this study endocytic activity at the synaptic pole of OHCs was investigated. Confocal laser scanning microscopy was used to visualize dye uptake of OHCs isolated from the guinea-pig cochlea. Signal intensity changes were quantified in the apical and basal poles relative to the signal at the membrane. Data showed no significant difference in fluorescent signal intensity changes between the opposite poles of the OHC. These results suggest that endocytic activities in both the basal and the apical poles contribute equally to the membrane recycling of OHCs.

  15. Predicting the location of missing outer hair cells using the electrical signal recorded at the round window

    PubMed Central

    Chertoff, Mark E.; Earl, Brian R.; Diaz, Francisco J.; Sorensen, Janna L.; Thomas, Megan L. A.; Kamerer, Aryn M.; Peppi, Marcello

    2014-01-01

    The electrical signal recorded at the round window was used to estimate the location of missing outer hair cells. The cochlear response was recorded to a low frequency tone embedded in high-pass filtered noise conditions. Cochlear damage was created by either overexposure to frequency-specific tones or laser light. In animals with continuous damage along the partition, the amplitude of the cochlear response increased as the high-pass cutoff frequency increased, eventually reaching a plateau. The cochlear distance at the onset of the plateau correlated with the anatomical onset of outer hair cell loss. A mathematical model replicated the physiologic data but was limited to cases with continuous hair cell loss in the middle and basal turns. The neural contribution to the cochlear response was determined by recording the response before and after application of Ouabain. Application of Ouabain eliminated or reduced auditory neural activity from approximately two turns of the cochlea. The amplitude of the cochlear response was reduced for moderate signal levels with a limited effect at higher levels, indicating that the cochlear response was dominated by outer hair cell currents at high signal levels and neural potentials at low to moderate signal levels. PMID:25190395

  16. Patch clamped responses from outer hair cells in the intact adult organ of Corti.

    PubMed

    Mammano, F; Kros, C J; Ashmore, J F

    1995-09-01

    Outer hair cells (OHCs) from the mammalian cochlea act as both sensory cells and motor cells. We report here whole-cell tight seal recordings of OHC activity in their natural embedding tissue, the intact organ of Corti, using a temporal bone preparation. The mean cell resting potential, -76 +/- 4 mV (n = 19) and input conductance (10 +/- 3 nS at -70 mV) of third turn hair cells were significantly lower than have been found in isolated cells. Two main K+ currents in the cell were identified. One current, activated positive to -100 mV, was reduced by 5 mM BaCl2. The other current, activated above -40 mV, was reduced by 100 microM 4-aminopyridine (4-AP) and by 30 mM tetraethylammonium (TEA). Both of these currents have been also identified in recordings reported from isolated cells. On stepping to different membrane potentials, cells imaged in the organ of Corti changed length by an amount large enough to cause visible distortions in neighbouring cells. By quantifying such distortions we estimate that the forces generated by OHCs can account for the enhanced response to sound required by the cochlear amplifier. PMID:7478927

  17. Effect of capsaicin on potassium conductance and electromotility of guinea pig outer hair cell

    PubMed Central

    Wu, T; Song, L; Shi, X; Jiang, Z; Santos-Sacchi, J; Nuttall, A.L

    2012-01-01

    Capsaicin, the classic activator of TRPV-1 channels in primary sensory neurons, evokes nociception. Interestingly, auditory reception is also modulated by this chemical, possibly by direct actions on outer hair cells (OHCs). Surprisingly, we find two novel actions of capsaicin unrelated to TRPV-1 channels, which likely contribute to its auditory effects in vivo. First, capsaicin is a potent blocker of OHC K conductances (IK and IK,n). Second, capsaicin substantially alters OHC nonlinear capacitance, the signature of electromotility – a basis of cochlear amplification. These new findings of capsaicin have ramifications for our understanding of the pharmacological properties of OHC IK, IK,n and electromotility and for interpretation of capsaicin pharmacological actions. PMID:21044673

  18. Compartmentalization of the outer hair cell demonstrated by slow diffusion in the extracisternal space.

    PubMed

    Gliko, Olga; Saggau, Peter; Brownell, William E

    2009-08-19

    In the outer hair cell (OHC), the extracisternal space (ECiS) is a conduit and reservoir of the molecular and ionic substrates of the lateral wall, including those necessary for electromotility. To determine the mechanisms through which molecules are transported in the ECiS of the OHC, we selectively imaged the time-dependent spatial distribution of fluorescent molecules in a <100 nm layer near the cell/glass interface of the recording chamber after their photolytic activation in a diffraction-limited volume. The effective diffusion coefficient was calculated using the analytical solution of the diffusion equation. It was found that diffusion in the ECiS is isotropic and not affected by depolarizing the OHC. Compared with free solution, the diffusion of 10 kDa dextran was slowed down in both the ECiS and the axial core by a factor of 4.6 and 1.6, respectively. PMID:19686670

  19. Acoustic stimulation causes tonotopic alterations in the length of isolated outer hair cells from guinea pig hearing organ.

    PubMed Central

    Canlon, B; Brundin, L; Flock, A

    1988-01-01

    Isolated outer hair cells from the mammalian cochlea exhibit a motile response to electrical or chemical stimulation. Here we show that isolated outer hair cells can also respond to acoustic stimulation, in the form of a tone burst of 200 Hz, by either shortening or lengthening depending on their cochlear location. Cells from the apical region of the cochlea (long cells) responded by increasing their length, whereas those from more basal regions (short cells) responded by decreasing their length. Cells from intermediate positions showed an equal probability for either elongating or shortening. Both the elongating and shortening response was inhibited by 3 microM poly(L-lysine). It is suggested that this tonotopic and bidirectional acoustic response may be one of the active components underlying the specific phase and frequency displacement of the basilar membrane. Images PMID:3413135

  20. TRPA1-mediated accumulation of aminoglycosides in mouse cochlear outer hair cells.

    PubMed

    Stepanyan, Ruben S; Indzhykulian, Artur A; Vélez-Ortega, A Catalina; Boger, Erich T; Steyger, Peter S; Friedman, Thomas B; Frolenkov, Gregory I

    2011-12-01

    Aminoglycoside ototoxicity involves the accumulation of antibiotic molecules in the inner ear hair cells and the subsequent degeneration of these cells. The exact route of entry of aminoglycosides into the hair cells in vivo is still unknown. Similar to other small organic cations, aminoglycosides could be brought into the cell by endocytosis or permeate through large non-selective cation channels, such as mechanotransduction channels or ATP-gated P2X channels. Here, we show that the aminoglycoside antibiotic gentamicin can enter mouse outer hair cells (OHCs) via TRPA1, non-selective cation channels activated by certain pungent compounds and by endogenous products of lipid peroxidation. Using conventional and perforated whole-cell patch clamp recordings, we found that application of TRPA1 agonists initiates inward current responses in wild-type OHCs, but not in OHCs of homozygous Trpa1 knockout mice. Similar responses consistent with the activation of non-selective cation channels were observed in heterologous cells transfected with mouse Trpa1. Upon brief activation with TRPA1 agonists, Trpa1-transfected cells become loaded with fluorescent gentamicin-Texas Red conjugate (GTTR). This uptake was not observed in mock-transfected or non-transfected cells. In mouse organ of Corti explants, TRPA1 activation resulted in the rapid entry of GTTR and another small cationic dye, FM1-43, in OHCs and some supporting cells, even when hair cell mechanotransduction was disrupted by pre-incubation in calcium-free solution. This TRPA1-mediated entry of GTTR and FM1-43 into OHCs was observed in wild-type but not in Trpa1 knockout mice and was not blocked by PPADS, a non-selective blocker of P2X channels. Notably, TRPA1 channels in mouse OHCs were activated by 4-hydroxynonenal, an endogenous molecule that is known to be generated during episodes of oxidative stress and accumulate in the cochlea after noise exposure. We concluded that TRPA1 channels may provide a novel pathway for

  1. A hydrodynamic model of an outer hair cell

    NASA Technical Reports Server (NTRS)

    Jacobson, B. O.

    1982-01-01

    On the model it is possible to measure the force and the force direction for each individual hair as a function of the flow direction and velocity. Measurements were made at the man flow velocity .01 m/s, which is equivalent to a flow velocity in the real ear of about 1 micrometer/s. The kinematic viscosity of the liquid used in the model was 10,000 times higher than the viscosity of perilymph to attain hydrodynamic equality. Two different geometries for the sterocilia pattern were tested. First the force distribution for a W-shaped sterocilia pattern was recorded. This is the sterocilia pattern found in all real ears. It is found that the forces acting on the hairs are very regular and perpendicular to the legs of the W when the flow is directed from the outside of the W. When the flow is reversed, the forces are not reversed, but are much more irregular. This can eventually explain the half wave rectification of the nerve signals. As a second experiment, the force distribution for a V-shaped sterocilia pattern was recorded. Here the forces were irregular both when the flow was directed into the V and when it was directed against the edge of the V.

  2. Potassium-induced release of an endogenous toxic activity for outer hair cells and auditory neurons in the cochlea: a new pathophysiological mechanism in Menière's disease?

    PubMed

    Lefebvre, P P; Weber, T; Rigo, J M; Delree, P; Leprince, P; Moonen, G

    1990-08-01

    In Menière's disease, the increase of extracellular potassium concentration in the perilymph is thought to play a key role in determining the progressive loss of cochlear hair cells. In this paper, we describe a serum-free culture preparation of hair cells from 5 day-old rat and report the release by the cochlea, in response to an increase of extracellular potassium concentration, of a cytotoxic activity active on hair cells and auditory neurons. The toxic activity is associated with low molecular weight (less than 10,000 Dalton) molecule(s) as revealed by ultrafiltration. Morphological studies performed on the organ of Corti incubated during 24 h in the presence of the cochlea-derived toxic activity (CTA), show that this factor is toxic for hair cells and not for supporting or surrounding cells. The release of CTA occurs both in the spiral ganglion and in the organ of Corti. We suggest that this cochlea-derived toxic activity may play an important role in the pathophysiology of the hearing loss that occurs during the progression of Menière's disease. PMID:2228800

  3. Selective Inner Hair Cell Dysfunction in Chinchillas Impairs Hearing-in-Noise in the Absence of Outer Hair Cell Loss.

    PubMed

    Lobarinas, Edward; Salvi, Richard; Ding, Dalian

    2016-04-01

    Poorer hearing in the presence of background noise is a significant problem for the hearing impaired. Ototoxic drugs, ageing, and noise exposure can damage the sensory hair cells of the inner ear that are essential for normal hearing sensitivity. The relationship between outer hair cell (OHC) loss and progressively poorer hearing sensitivity in quiet or in competing background noise is supported by a number of human and animal studies. In contrast, the effect of moderate inner hair cell (IHC) loss or dysfunction shows almost no impact on behavioral measures of hearing sensitivity in quiet, when OHCs remain intact, but the relationship between selective IHC loss and hearing in noise remains relatively unknown. Here, a moderately high dose of carboplatin (75 mg/kg) that produced IHC loss in chinchillas ranging from 40 to 80 % had little effect on thresholds in quiet. However, when tested in the presence of competing broadband (BBN) or narrowband noise (NBN), thresholds increased significantly. IHC loss >60 % increased signal-to-noise ratios (SNRs) for tones (500-11,300 Hz) in competing BBN by 5-10 dB and broadened the masking function under NBN. These data suggest that IHC loss or dysfunction may play a significant role in listening in noise independent of OHC integrity and that these deficits may be present even when thresholds in quiet are within normal limits. PMID:26691159

  4. Shape deformation of the organ of Corti associated with length changes of outer hair cell

    NASA Technical Reports Server (NTRS)

    Zimmermann, U.; Fermin, C.

    1996-01-01

    Cochlear outer hair cells (OHC) are commonly assumed to function as mechanical effectors as well as sensory receptors in the organ of Corti (OC) of the inner ear. OHC in vitro and in organ explants exhibit mechanical responses to electrical, chemical or mechanical stimulation which may represent an aspect of their effector process that is expected in vivo. A detailed description, however, of an OHC effector operation in situ is still missing. Specifically, little is known as to how OHC movements influence the geometry of the OC in situ. Previous work has demonstrated that the motility of isolated OHCs in response to electrical stimulation and to K(+)-gluconate is probably under voltage control and causes depolarisation (shortening) and hyperpolarization (elongation). This work was undertaken to investigate if the movements that were observed in isolated OHC, and which are induced by ionic stimulation, could change the geometry of the OC. A synchronized depolarization of OHC was induced in guinea pig cochleae by exposing the entire OC to artificial endolymph (K+). Subsequent morphometry of mid-modiolar sections from these cochleae revealed that the distance between the basilar membrane (BM) and the reticular lamina (RL) had decreased considerably. Furthermore, in the three upper turns OHC had significantly shortened in all rows. The results suggest that OHC can change their length in the organ of Corti (OC) thus deforming the geometry of the OC. The experiments reveal a tonic force generation within the OC that may change the position of RL and/or BM, contribute to damping, modulate the BM-RL-distance and control the operating points of RL and sensory hair bundles. Thus, the results suggest active self-adjustments of cochlear mechanics by slow OHC length changes. Such mechanical adjustments have recently been postulated to correspond to timing elements of animal communication, speech or music.

  5. Somatic stiffness of cochlear outer hair cells is voltage-dependent.

    PubMed

    He, D Z; Dallos, P

    1999-07-01

    The mammalian cochlea depends on an amplification process for its sensitivity and frequency-resolving capability. Outer hair cells are responsible for providing this amplification. It is usually assumed that the membrane-potential-driven somatic shape changes of these cells are the basis of the amplifying process. It is of interest to see whether mechanical reactance changes of the cells might accompany their changes in cell shape. We now show that the cylindrical outer hair cells change their axial stiffness as their membrane potential is altered. Cell stiffness was determined by optoelectronically measuring the amplitude of motion of a flexible vibrating fiber as it was loaded by the isolated cell. Voltage commands to the cell were delivered in a tight-seal whole-cell configuration. Cell stiffness was decreased by depolarization and increased by hyperpolarization. PMID:10393976

  6. Localization of kainate receptors in inner and outer hair cell synapses

    PubMed Central

    Fujikawa, Taro; Petralia, Ronald S.; Fitzgerald, Tracy S.; Wang, Ya-Xian; Millis, Bryan; Morgado-Díaz, José Andrés; Kitamura, Ken; Kachar, Bechara

    2014-01-01

    Glutamate plays a role in hair cell afferent transmission, but the receptors that mediate neurotransmission between outer hair cells (OHCs) and type II ganglion neurons are not well defined. A previous study using in situ hybridization showed that several kainate-type glutamate receptor (KAR) subunits are expressed in cochlear ganglion neurons. To determine whether KARs are expressed in hair cell synapses, we performed X-gal staining on mice expressing lacZ driven by the GluK5 promoter, and immunolabeling of glutamate receptors in whole-mount mammalian cochleae. X-gal staining revealed GluK5 expression in both type I and type II ganglion neurons and OHCs in adults. OHCs showed X-gal reactivity throughout maturation from postnatal day 4 (P4) to 1.5 months. Immunoreactivity for GluK5 in IHC afferent synapses appeared to be postsynaptic, similar to GluA2 (GluR2; AMPA-type glutamate receptor (AMPAR) subunit), while GluK2 may be on both sides of the synapses. In OHC afferent synapses, immunoreactivity for GluK2 and GluK5 was found, although GluK2 was only in those synapses bearing ribbons. GluA2 was not detected in adult OHC afferent synapses. Interestingly, GluK1, GluK2 and GluK5 were also detected in OHC efferent synapses, forming several active zones in each synaptic area. At P8, GluA2 and all KAR subunits except GluK4 were detected in OHC afferent synapses in the apical turn, and GluA2, GluK1, GluK3 decreased dramatically in the basal turn. These results indicate that AMPARs and KARs (GluK2/GluK5) are localized to IHC afferent synapses, while only KARs (GluK2/GluK5) are localized to OHC afferent synapses in adults. Glutamate spillover near OHCs may act on KARs in OHC efferent terminals to modulate transmission of acoustic information and OHC electromotility. PMID:24858010

  7. Outer Hair Cell Lateral Wall Structure Constrains the Mobility of Plasma Membrane Proteins.

    PubMed

    Yamashita, Tetsuji; Hakizimana, Pierre; Wu, Siva; Hassan, Ahmed; Jacob, Stefan; Temirov, Jamshid; Fang, Jie; Mellado-Lagarde, Marcia; Gursky, Richard; Horner, Linda; Leibiger, Barbara; Leijon, Sara; Centonze, Victoria E; Berggren, Per-Olof; Frase, Sharon; Auer, Manfred; Brownell, William E; Fridberger, Anders; Zuo, Jian

    2015-09-01

    Nature's fastest motors are the cochlear outer hair cells (OHCs). These sensory cells use a membrane protein, Slc26a5 (prestin), to generate mechanical force at high frequencies, which is essential for explaining the exquisite hearing sensitivity of mammalian ears. Previous studies suggest that Slc26a5 continuously diffuses within the membrane, but how can a freely moving motor protein effectively convey forces critical for hearing? To provide direct evidence in OHCs for freely moving Slc26a5 molecules, we created a knockin mouse where Slc26a5 is fused with YFP. These mice and four other strains expressing fluorescently labeled membrane proteins were used to examine their lateral diffusion in the OHC lateral wall. All five proteins showed minimal diffusion, but did move after pharmacological disruption of membrane-associated structures with a cholesterol-depleting agent and salicylate. Thus, our results demonstrate that OHC lateral wall structure constrains the mobility of plasma membrane proteins and that the integrity of such membrane-associated structures are critical for Slc26a5's active and structural roles. The structural constraint of membrane proteins may exemplify convergent evolution of cellular motors across species. Our findings also suggest a possible mechanism for disorders of cholesterol metabolism with hearing loss such as Niemann-Pick Type C diseases. PMID:26352669

  8. Distribution of Ca2+ channels on cochlear outer hair cells revealed by fluorescent dihydropyridines.

    PubMed

    Oshima, T; Ikeda, K; Furukawa, M; Ueda, N; Suzuki, H; Takasaka, T

    1996-09-01

    Physiological evidence has shown that cochlear outer hair cells (OHC) possess L-type voltage-dependent Ca2+ channels through which Ca2+ enters the OHC during depolarization. Their subcellular distribution has, however, remained unclear. In this study, the distribution of L-type Ca2+ channels on the basolateral plasma membrane of OHC has been demonstrated by the use of a laser scanning confocal microscope (LSCM) and a fluorescent probe DMBODIPY-DHP. The fluorescent staining pattern on the basolateral wall is nonuniform, suggesting a heterogeneous distribution of the channels in the plasma membrane. Direct imaging of intracellular Ca2+ visualized in real time by means of the LSCM and the fluorescent Ca2+ probe fluo 3 revealed temporal and spatial integration of Ca2+ movements and Ca2+ channel distribution. Exposure to high-K+ solution induced heterogeneity in the subcellular increase in the intracellular Ca2+ concentration. These results suggest that the heterogeneous distribution of L-type Ca2+ channels on the basolateral membrane might induce heterogeneous intracellular Ca2+ distribution during electrical activity in the OHC. PMID:8843725

  9. Outer Hair Cell Lateral Wall Structure Constrains the Mobility of Plasma Membrane Proteins

    PubMed Central

    Yamashita, Tetsuji; Hakizimana, Pierre; Wu, Siva; Hassan, Ahmed; Jacob, Stefan; Temirov, Jamshid; Fang, Jie; Mellado-Lagarde, Marcia; Gursky, Richard; Horner, Linda; Leibiger, Barbara; Leijon, Sara; Centonze, Victoria E.; Berggren, Per-Olof; Frase, Sharon; Auer, Manfred; Brownell, William E.; Fridberger, Anders; Zuo, Jian

    2015-01-01

    Nature’s fastest motors are the cochlear outer hair cells (OHCs). These sensory cells use a membrane protein, Slc26a5 (prestin), to generate mechanical force at high frequencies, which is essential for explaining the exquisite hearing sensitivity of mammalian ears. Previous studies suggest that Slc26a5 continuously diffuses within the membrane, but how can a freely moving motor protein effectively convey forces critical for hearing? To provide direct evidence in OHCs for freely moving Slc26a5 molecules, we created a knockin mouse where Slc26a5 is fused with YFP. These mice and four other strains expressing fluorescently labeled membrane proteins were used to examine their lateral diffusion in the OHC lateral wall. All five proteins showed minimal diffusion, but did move after pharmacological disruption of membrane-associated structures with a cholesterol-depleting agent and salicylate. Thus, our results demonstrate that OHC lateral wall structure constrains the mobility of plasma membrane proteins and that the integrity of such membrane-associated structures are critical for Slc26a5’s active and structural roles. The structural constraint of membrane proteins may exemplify convergent evolution of cellular motors across species. Our findings also suggest a possible mechanism for disorders of cholesterol metabolism with hearing loss such as Niemann-Pick Type C diseases. PMID:26352669

  10. Membrane Composition Tunes the Outer Hair Cell Motor

    NASA Astrophysics Data System (ADS)

    Rajagopalan, L.; Sfondouris, J.; Oghalai, J. S.; Pereira, F. A.; Brownell, W. E.

    2009-02-01

    Cholesterol and docosahexaenoic acid (DHA), an ω-3 fatty acid, affect membrane mechanical properties in different ways and modulate the function of membrane proteins. We have probed the functional consequence of altering cholesterol and DHA levels in the membranes of OHCs and prestin expressing HEK cells. Large, dynamic and reversible changes in prestin-associated charge movement and OHC motor activity result from altering the concentration of membrane cholesterol. Increasing membrane cholesterol shifts the q/V function ~ 50 mV in the hyperpolarizing direction, possibly a response related to increases in membrane stiffness. The voltage shift is linearly related to total membrane cholesterol. Increasing cholesterol also decreases the total charge moved in a linear fashion. Decreasing membrane cholesterol shifts the q/V function ~ 50 mV in the depolarizing direction with little or no effect on the amount of charge moved. In vivo increases in membrane cholesterol transiently increase but ultimately lead to decreases in DPOAE. Docosahexaenoic acid shifts the q/V function in the hyperpolarizing direction < 15 mV and increases total charge moved. Tuning of cochlear function by membrane cholesterol contributes to the exquisite temporal and frequency processing of mammalian hearing by optimizing the cochlear amplifier.

  11. A Cochlear Partition Model Incorporating Realistic Electrical and Mechanical Parameters for Outer Hair Cells

    NASA Astrophysics Data System (ADS)

    Nam, Jong-Hoon; Fettiplace, Robert

    2011-11-01

    The organ of Corti (OC) is believed to optimize the force transmission from the outer hair cell (OHC) to the basilar membrane and inner hair cell. Recent studies showed that the OC has complex modes of deformation. In an effort to understand the consequence of the OC deformation, we developed a fully deformable 3D finite element model of the OC. It incorporates hair bundle's mechano-transduction and the OHC electrical circuit. Geometric information was taken from the gerbil cochlea at locations with 18 and 0.7 kHz characteristic frequencies. Cochlear partitions of several hundred micrometers long were simulated. The model describes the signature 3D structural arrangement in the OC, especially the tilt of OHC and Deiters cell process. Transduction channel kinetics contributed to the system's mechanics through the hair bundle. The OHC electrical model incorporated the transduction channel conductance, nonlinear capacitance and piezoelectric properties. It also incorporated recent data on the voltage-dependent potassium conductance and membrane time constant. With the model we simulated (1) the limiting frequencies of mechano-transduction and OHC somatic motility and (2) OC transient response to impulse stimuli.

  12. PKCα-Mediated Signals Regulate the Motile Responses of Cochlear Outer Hair Cells

    PubMed Central

    Park, Channy; Kalinec, Federico

    2015-01-01

    There is strong evidence that changes in the actin/spectrin-based cortical cytoskeleton of outer hair cells (OHCs) regulate their motile responses as well as cochlear amplification, the process that optimizes the sensitivity and frequency selectivity of the mammalian inner ear. Since a RhoA/protein kinase C (PKC)-mediated pathway is known to inhibit the actin-spectrin interaction in other cell models, we decided to investigate whether this signaling cascade could also participate in the regulation of OHC motility. We used high-speed video microscopy and confocal microscopy to explore the effects of pharmacological activation of PKCα, PKCβI, PKCβII, PKCδ, PKCε, and PKCζ with lysophosphatidic acid (LPA) and their inhibition with bisindolylmaleimide I, as well as inhibition of RhoA and Rho-associated protein kinase (ROCK) with C3 and Y-27632, respectively. Motile responses were induced in isolated guinea pig OHCs by stimulation with an 8 V/cm external alternating electrical field as 50 Hz bursts of square wave pulses (100 ms on/off). We found that LPA increased expression of PKCα and PKCζ only, with PKCα, but not PKCζ, phosphorylating the cytoskeletal protein adducin of both Ser-726 and Thr-445. Interestingly, however, inhibition of PKCα reduced adducin phosphorylation only at Ser-726. We also determined that LPA activation of a PKCα-mediated signaling pathway simultaneously enhanced OHC electromotile amplitude and cell shortening, and facilitated RhoA/ROCK/LIMK1-mediated cofilin phosphorylation. Altogether, our results suggest that PKCα-mediated signals, probably via adducin-mediated inhibition of actin-spectrin binding and cofilin-mediated depolymerization of actin filaments, play an essential role in the homeostatic regulation of OHC motility and cochlear amplification. PMID:25954875

  13. Transitory endolymph leakage induced hearing loss and tinnitus: depolarization, biphasic shortening and loss of electromotility of outer hair cells

    NASA Technical Reports Server (NTRS)

    Zenner, H. P.; Reuter, G.; Zimmermann, U.; Gitter, A. H.; Fermin, C.; LePage, E. L.

    1994-01-01

    There are types of deafness and tinnitus in which ruptures or massive changes in the ionic permeability of the membranes lining the endolymphatic space [e.g., of the reticular lamina (RL)] are believed to allow potassium-rich endolymph to deluge the low [K+] perilymphatic fluid (e.g., in the small spaces of Nuel). This would result in a K+ intoxication of sensory and neural structures. Acute attacks of Meniere's disease have been suggested to be an important example for this event. The present study investigated the effects of transiently elevated [K+] due to the addition of artificial endolymph to the basolateral cell surface of outer hair cells (OHC) in replicating endolymph-induced K+ intoxication of the perilymph in the small spaces of Nuel. The influence of K+ intoxication of the basolateral OHC cell surface on the transduction was then examined. Intoxication resulted in an inhibition of the physiological repolarizing K+ efflux from hair cells. This induced unwanted depolarizations of the hair cells, interfering with mechanoelectrical transduction. A pathological longitudinal OHC shortening was also found, with subsequent compression of the organ of Corti possibly influencing the micromechanics of the mechanically active OHC. Both micromechanical and electrophysiological alterations are proposed to contribute to endolymph leakage induced attacks of deafness and possibly also to tinnitus. Moreover, repeated or long-lasting K+ intoxications of OHC resulted in a chronic and complete loss of OHC motility. This is suggested to be a pathophysiological basis in some patients with chronic hearing loss resulting from Meniere's syndrome.

  14. Mapping gene activity of Arabidopsis root hairs

    PubMed Central

    2013-01-01

    Background Quantitative information on gene activity at single cell-type resolution is essential for the understanding of how cells work and interact. Root hairs, or trichoblasts, tubular-shaped outgrowths of specialized cells in the epidermis, represent an ideal model for cell fate acquisition and differentiation in plants. Results Here, we provide an atlas of gene and protein expression in Arabidopsis root hair cells, generated by paired-end RNA sequencing and LC/MS-MS analysis of protoplasts from plants containing a pEXP7-GFP reporter construct. In total, transcripts of 23,034 genes were detected in root hairs. High-resolution proteome analysis led to the reliable identification of 2,447 proteins, 129 of which were differentially expressed between root hairs and non-root hair tissue. Dissection of pre-mRNA splicing patterns showed that all types of alternative splicing were cell type-dependent, and less complex in EXP7-expressing cells when compared to non-root hair cells. Intron retention was repressed in several transcripts functionally related to root hair morphogenesis, indicative of a cell type-specific control of gene expression by alternative splicing of pre-mRNA. Concordance between mRNA and protein expression was generally high, but in many cases mRNA expression was not predictive for protein abundance. Conclusions The integrated analysis shows that gene activity in root hairs is dictated by orchestrated, multilayered regulatory mechanisms that allow for a cell type-specific composition of functional components. PMID:23800126

  15. Transcription Factors Expressed in Mouse Cochlear Inner and Outer Hair Cells

    PubMed Central

    Li, Yi; Liu, Huizhan; Barta, Cody L.; Judge, Paul D.; Zhao, Lidong; Zhang, Weiping J.; Gong, Shusheng; Beisel, Kirk W.; He, David Z. Z.

    2016-01-01

    Regulation of gene expression is essential to determining the functional complexity and morphological diversity seen among different cells. Transcriptional regulation is a crucial step in gene expression regulation because the genetic information is directly read from DNA by sequence-specific transcription factors (TFs). Although several mouse TF databases created from genome sequences and transcriptomes are available, a cell type-specific TF database from any normal cell populations is still lacking. We identify cell type-specific TF genes expressed in cochlear inner hair cells (IHCs) and outer hair cells (OHCs) using hair cell-specific transcriptomes from adult mice. IHCs and OHCs are the two types of sensory receptor cells in the mammalian cochlea. We show that 1,563 and 1,616 TF genes are respectively expressed in IHCs and OHCs among 2,230 putative mouse TF genes. While 1,536 are commonly expressed in both populations, 73 genes are differentially expressed (with at least a twofold difference) in IHCs and 13 are differentially expressed in OHCs. Our datasets represent the first cell type-specific TF databases for two populations of sensory receptor cells and are key informational resources for understanding the molecular mechanism underlying the biological properties and phenotypical differences of these cells. PMID:26974322

  16. Transcription Factors Expressed in Mouse Cochlear Inner and Outer Hair Cells.

    PubMed

    Li, Yi; Liu, Huizhan; Barta, Cody L; Judge, Paul D; Zhao, Lidong; Zhang, Weiping J; Gong, Shusheng; Beisel, Kirk W; He, David Z Z

    2016-01-01

    Regulation of gene expression is essential to determining the functional complexity and morphological diversity seen among different cells. Transcriptional regulation is a crucial step in gene expression regulation because the genetic information is directly read from DNA by sequence-specific transcription factors (TFs). Although several mouse TF databases created from genome sequences and transcriptomes are available, a cell type-specific TF database from any normal cell populations is still lacking. We identify cell type-specific TF genes expressed in cochlear inner hair cells (IHCs) and outer hair cells (OHCs) using hair cell-specific transcriptomes from adult mice. IHCs and OHCs are the two types of sensory receptor cells in the mammalian cochlea. We show that 1,563 and 1,616 TF genes are respectively expressed in IHCs and OHCs among 2,230 putative mouse TF genes. While 1,536 are commonly expressed in both populations, 73 genes are differentially expressed (with at least a twofold difference) in IHCs and 13 are differentially expressed in OHCs. Our datasets represent the first cell type-specific TF databases for two populations of sensory receptor cells and are key informational resources for understanding the molecular mechanism underlying the biological properties and phenotypical differences of these cells. PMID:26974322

  17. A Study of Noncultured Extracted Hair Follicle Outer Root Sheath Cell Suspension for Transplantation in Vitiligo

    PubMed Central

    Shah, Aarti N; Marfatia, Ritu K; Saikia, Siddhartha S

    2016-01-01

    Context: Vitiligo surgeries have come a long way from tissue grafts to cultured and non cultured cell transplantation. Extracted hair follicle outer root sheath cell transplantation (EHF ORS) suspension is more enriched with melanocyte. In a hair bulb, there is one melanocyte for every five keratinocytes which is much higher than the epidermal melanin unit. Aims: To analyse the effectiveness of cultured EHF ORS and to perform objective evaluation based on clinical improvement & photographic evidence. To observe any untoward events or side effects. Settings and Design: The study was open and uncontrolled. All the patients were screened at preliminary visit. Reviews were done every two weeks. The endpoint selected was six months post procedure. Materials and Methods: Twenty five patients of stable Vitiligo were included in the study and follicular unit were harvested by Follicular Unit Extraction method. Outer root sheath cells were extracted by trypsinization. The solution was transplanted over dermabraded recipient site. Pressure dressing was given. Patients were followed up regularly. Statistical Analysis Used: Descriptive Statistics, Chi-Square. Results: Mean ± SD repigmentation was 80.15% ± 22.9% with excellent repigmentation (90-100%) in 60% of patients. Conclusions: This method is safe, effective, and simpler than the other methods involving cell culturing and requiring a laboratory set-up but selection of patients is crucial for the success of the outcome. PMID:27601859

  18. The cochlear amplifier as a standing wave: ``Squirting'' waves between rows of outer hair cells?

    NASA Astrophysics Data System (ADS)

    Bell, Andrew; Fletcher, Neville H.

    2004-08-01

    This paper draws attention to symmetric Lloyd-Redwood (SLR) waves-known in ultrasonics as ``squirting'' waves-and points out that their distinctive properties make them well-suited for carrying positive feedback between rows of outer hair cells. This could result in standing-wave resonance-in essence a narrow-band cochlear amplifier. Based on known physical properties of the cochlea, such an amplifier can be readily tuned to match the full 10-octave range of human hearing. SLR waves propagate in a thin liquid layer enclosed between two thin compliant plates or a single such plate and a rigid wall, conditions found in the subtectorial space of the cochlea, and rely on the mass of the inter-plate fluid interacting with the stiffness of the plates to provide low phase velocity and high dispersion. The first property means SLR wavelengths can be as short as the distance between rows of outer hair cells, allowing standing wave formation; the second permits wide-range tuning using only an order-of-magnitude variation in cochlear physical properties, most importantly the inter-row spacing. Viscous drag at the two surfaces potentially limits SLR wave propagation at low frequencies, but this can perhaps be overcome by invoking hydrophobic effects.

  19. Polycaprolactone fiber meshes provide a 3D environment suitable for cultivation and differentiation of melanocytes from the outer root sheath of hair follicle.

    PubMed

    Savkovic, Vuk; Flämig, Franziska; Schneider, Marie; Sülflow, Katharina; Loth, Tina; Lohrenz, Andrea; Hacker, Michael Christian; Schulz-Siegmund, Michaela; Simon, Jan-Christoph

    2016-01-01

    Melanocytes differentiated from the stem cells of human hair follicle outer root sheath (ORS) have the potential for developing non-invasive treatments for skin disorders out of a minimal sample: of hair root. With a robust procedure for melanocyte cultivation from the ORS of human hair follicle at hand, this study focused on the identification of a suitable biocompatible, biodegradable carrier as the next step toward their clinical implementation. Polycaprolactone (PCL) is a known biocompatible material used for a number of medical devices. In this study, we have populated electrospun PCL fiber meshes with normal human epidermal melanocytes (NHEM) as well as with hair-follicle-derived human melanocytes from the outer root sheath (HUMORS) and tested their functionality in vitro. PCL fiber meshes evidently provided a niche for melanocytes and supported their melanotic properties. The cells were tested for gene expression of PAX3, PMEL, TYR and MITF, as well as for proliferation, expression of melanocyte marker proteins tyrosinase and glycoprotein 100 (gp100), L-DOPA-tautomerase enzymatic activity and melanin content. Reduced mitochondrial activity and PAX-3 gene expression indicated that the three-dimensional PCL scaffold supported differentiation rather than proliferation of melanocytes. The monitored melanotic features of both the NHEM and HUMORS cultivated on PCL scaffolds significantly exceeded those of two-dimensional adherent cultures. PMID:26126647

  20. Prestin-Dependence of Outer Hair Cell Survival and Partial Rescue of Outer Hair Cell Loss in PrestinV499G/Y501H Knockin Mice.

    PubMed

    Cheatham, Mary Ann; Edge, Roxanne M; Homma, Kazuaki; Leserman, Emily L; Dallos, Peter; Zheng, Jing

    2015-01-01

    A knockin (KI) mouse expressing mutated prestinV499G/Y501H (499 prestin) was created to study cochlear amplification. Recordings from isolated outer hair cells (OHC) in this mutant showed vastly reduced electromotility and, as a consequence, reduced hearing sensitivity. Although 499 prestin OHCs were normal in stiffness and longer than OHCs lacking prestin, accelerated OHC death was unexpectedly observed relative to that documented in prestin knockout (KO) mice. These observations imply an additional role of prestin in OHC maintenance besides its known requirement for mammalian cochlear amplification. In order to gain mechanistic insights into prestin-associated OHC loss, we implemented several interventions to improve survival. First, 499 prestin KI's were backcrossed to Bak KO mice, which lack the mitochondrial pro-apoptotic gene Bak. Because oxidative stress is implicated in OHC death, another group of 499 prestin KI mice was fed the antioxidant diet, Protandim. 499 KI mice were also backcrossed onto the FVB murine strain, which retains excellent high-frequency hearing well into adulthood, to reduce the compounding effect of age-related hearing loss associated with the original 499 prestin KIs. Finally, a compound heterozygous (chet) mouse expressing one copy of 499 prestin and one copy of KO prestin was also created to reduce quantities of 499 prestin protein. Results show reduction in OHC death in chets, and in 499 prestin KIs on the FVB background, but only a slight improvement in OHC survival for mice receiving Protandim. We also report that improved OHC survival in 499 prestin KIs had little effect on hearing phenotype, reaffirming the original contention about the essential role of prestin's motor function in cochlear amplification. PMID:26682723

  1. Prestin-Dependence of Outer Hair Cell Survival and Partial Rescue of Outer Hair Cell Loss in PrestinV499G/Y501H Knockin Mice

    PubMed Central

    Cheatham, Mary Ann; Edge, Roxanne M.; Homma, Kazuaki; Leserman, Emily L.; Dallos, Peter; Zheng, Jing

    2015-01-01

    A knockin (KI) mouse expressing mutated prestinV499G/Y501H (499 prestin) was created to study cochlear amplification. Recordings from isolated outer hair cells (OHC) in this mutant showed vastly reduced electromotility and, as a consequence, reduced hearing sensitivity. Although 499 prestin OHCs were normal in stiffness and longer than OHCs lacking prestin, accelerated OHC death was unexpectedly observed relative to that documented in prestin knockout (KO) mice. These observations imply an additional role of prestin in OHC maintenance besides its known requirement for mammalian cochlear amplification. In order to gain mechanistic insights into prestin-associated OHC loss, we implemented several interventions to improve survival. First, 499 prestin KI’s were backcrossed to Bak KO mice, which lack the mitochondrial pro-apoptotic gene Bak. Because oxidative stress is implicated in OHC death, another group of 499 prestin KI mice was fed the antioxidant diet, Protandim. 499 KI mice were also backcrossed onto the FVB murine strain, which retains excellent high-frequency hearing well into adulthood, to reduce the compounding effect of age-related hearing loss associated with the original 499 prestin KIs. Finally, a compound heterozygous (chet) mouse expressing one copy of 499 prestin and one copy of KO prestin was also created to reduce quantities of 499 prestin protein. Results show reduction in OHC death in chets, and in 499 prestin KIs on the FVB background, but only a slight improvement in OHC survival for mice receiving Protandim. We also report that improved OHC survival in 499 prestin KIs had little effect on hearing phenotype, reaffirming the original contention about the essential role of prestin’s motor function in cochlear amplification. PMID:26682723

  2. A Case of Basal Cell Carcinoma with Outer Hair Follicle Sheath Differentiation.

    PubMed

    Onishi, Masazumi; Takahashi, Kazuhiro; Maeda, Fumihiko; Akasaka, Toshihide

    2015-01-01

    A 70-year-old Japanese man presented at our hospital with an asymptomatic, blackish, irregularly shaped plaque with a gray nodule in the periphery on his left lower leg. The lesion had been present for 10 years and had recently enlarged, associated with bleeding. Histopathologically, the tumor consisted of three distinct parts: The first part showed massive aggregation of basophilic basaloid cells with peripheral palisading and abundant melanin granules, and was diagnosed as solid-type basal cell carcinoma. The second part showed aggregation of clear cells with squamous eddies, and was diagnosed as proliferating trichilemmal tumor. The third part showed reticular aggregation of basaloid cells with infundibular cysts in the papillary dermis, and was diagnosed as infundibulocystic basal cell carcinoma. We diagnosed this tumor as basal cell carcinoma with various forms of hair follicle differentiation, including differentiation into the outer root sheath. PMID:26955331

  3. Current noise spectrum and capacitance due to the membrane motor of the outer hair cell: theory.

    PubMed Central

    Iwasa, K H

    1997-01-01

    The voltage-dependent motility of the outer hair cell is based on a membrane motor densely distributed in the lateral membrane. The gating charge of the membrane motor is manifested as a bell-shaped membrane potential dependence of the membrane capacitance. In this paper it is shown that movements of the gating charge should produce a high-pass current noise described by an inverse Lorentzian similar to the one shown by Kolb and Läuger for ion carriers. The frequency dependence of the voltage-dependent capacitance is also derived. These derivations are based on membrane motor models with two or three states. These two models lead to similar predictions on the capacitance and current noise. It is expected that the examination of the spectral properties of these quantities would be a useful means of determining the relaxation time for conformational transitions of the membrane motor. PMID:9414211

  4. A Case of Basal Cell Carcinoma with Outer Hair Follicle Sheath Differentiation

    PubMed Central

    Onishi, Masazumi; Takahashi, Kazuhiro; Maeda, Fumihiko; Akasaka, Toshihide

    2015-01-01

    A 70-year-old Japanese man presented at our hospital with an asymptomatic, blackish, irregularly shaped plaque with a gray nodule in the periphery on his left lower leg. The lesion had been present for 10 years and had recently enlarged, associated with bleeding. Histopathologically, the tumor consisted of three distinct parts: The first part showed massive aggregation of basophilic basaloid cells with peripheral palisading and abundant melanin granules, and was diagnosed as solid-type basal cell carcinoma. The second part showed aggregation of clear cells with squamous eddies, and was diagnosed as proliferating trichilemmal tumor. The third part showed reticular aggregation of basaloid cells with infundibular cysts in the papillary dermis, and was diagnosed as infundibulocystic basal cell carcinoma. We diagnosed this tumor as basal cell carcinoma with various forms of hair follicle differentiation, including differentiation into the outer root sheath. PMID:26955331

  5. Tilt of the Outer Hair Cell Lattice:. Origin of Dual Tuning Tips and Cochlear Bandwidth

    NASA Astrophysics Data System (ADS)

    Bell, Andrew; Maddess, Ted

    2009-02-01

    Using spatial autocorrelation analysis of published outer hair cell stereovilli positions in a primate, this work measured average spacing between cells. We find that the OHCs occupy a nearly rectangular unit cell that, from base to apex, exhibits a consistent tilt of about 4°. The implications of this "tilted box" geometry in terms of the squirting wave model of the cochlear amplifier are examined, and two major conclusions emerge. (1) The minimum and maximum wavelengths accommodated by the short and long diagonals of the tilted box (directions reinforced by the 'V'-shaped arms of the stereovilli) allow two distinct frequencies to map to every place. (2) The amount of tilt dictates the difference between these two frequencies - i.e., the relative bandwidth or Q. Thus, a 4° tilt leads by simple geometry to a Q of about 12 at 1 kHz and 25 at 8 kHz, figures in line with some otoacoustic and psychophysical results.

  6. Specialized features of the outer hair cell shapes in the cochlear fovea of bats.

    PubMed

    Zhang, S Q; Li, S L; Zhu, H L; Yan, L Y

    2015-01-01

    In this study, we examined the specialized features of the outer hair cells (OHCs) and the stereocilium bundles of the bat cochlear fovea. Bat cochlea hair cells were observed by scanning and transmission electron microscopy, and the auditory brainstem response thresholds were assessed. The stereocilia bundles of the OHCs were extremely short. The OHC bodies were flask-shaped and cambiform or ball-shape in the cochlear fovea. Digitations in the Deiters cells had exaggerated lengths, and cup formation of the Deiters cell, housed at the bottom of the OHC in the base of the cell, showed a specialized shape. Our results provide the first evidence that different shapes of the OHCs in the cochlea fovea are related to the high-frequency function of auditory response. Echolocating bats have cochlear morphologies that differ from those of non-echolocating animals. Bat cochlear foveae are specialized for analyzing the Doppler-shifted echoes of the first-harmonics of the CF2 component; these are overrepresented in the frequency range around the dominant harmonic of the echolocation calls of bats. However, the OHCs of the bat cochlear fovea have not been fully characterized. PMID:26345886

  7. Estimation of optimal insertion angle in a mammalian outer hair cell stereocilium.

    PubMed

    Baek, Jong Dae; Yoon, Yong-Jin; Abedinnasab, Mohammad H; Han, Beibei; Kwak, Sang Kyu

    2012-06-26

    Optimal insertion angle of mammalian stereocilia is estimated from the finite element analysis of the tip motion of outer hair cells (OHCs) stereocilia. The OHC stereocilia motion in the acousticolateral system appears to result in the mechanoelectrical transduction channels. Deflection of the hair bundle towards the tallest row of stereocilia causes increased probability of opening of ion channels. In this work, we focus on one of the physical features of the OHC stereocilium, the initial insertion angle of the tallest row into the tectorial membrane (TM), and its effects on the stereocilia's deflection motion. A three-dimensional model was built for the tallest stereocilium and the TM at the region where the best frequency was 500Hz. The mechanical interactions between the embedded stereocilia and the TM have been implemented into the finite element simulation. We found that, the optimum insertion angle of the tallest stereocilium into the TM was 69.8°, where the stereocilium is maximally deflected. This quantity is consistent with the histological observation obtained from the literature. PMID:22591639

  8. Cav 1.3 (α1D) Ca2+ currents in neonatal outer hair cells of mice

    PubMed Central

    Michna, Marcus; Knirsch, Martina; Hoda, Jean-Charles; Muenkner, Stefan; Langer, Patricia; Platzer, Josef; Striessnig, Jörg; Engel, Jutta

    2003-01-01

    Outer hair cells (OHC) serve as electromechanical amplifiers that guarantee the unique sensitivity and frequency selectivity of the mammalian cochlea. It is unknown whether the afferent fibres connected to adult OHCs are functional. If so, voltage-activated Ca2+ channels would be required for afferent synaptic transmission. In neonatal OHCs, Ca2+ channels seem to play a role in maturation since OHCs from Cav1.3-deficient (Cav1.3−/−) mice degenerate shortly after the onset of hearing. We therefore studied whole-cell Ca2+ currents in outer hair cells aged between postnatal day 1 (P1) and P8. OHCs showed a rapidly activating inward current that was 1.8 times larger with 10 mm Ba2+ as charge carrier (IBa) than with equimolar Ca2+ (ICa). IBa started activating at −50 mV with Vmax = −1.9 ± 6.9 mV, V0.5 = −15.0 ± 7.1 mV and k = 8.2± 1.1 mV (n = 34). The peak IBa showed negligible inactivation (3.6 % after 300 ms) whereas the ICa (10 mm Ca2+) was inactivated by 50.7 %. OHC IBa was reduced by 33.5 ± 10.3 % (n = 14) with 10 μm nifedipine and increased to 178.5 ± 57.8 % (n = 14) by 5 μm Bay K 8644. A dose-response curve for nifedipine revealed an IC50 of 2.3 μm, a Hill coefficient of 2.7 and a maximum block of 36 %. Average IBa density in OHCs was 24.4 ± 10.8 pA pF−1 (n = 105) which is only 38 % of the value in inner hair cells. Single cell RT-PCR revealed expression of Cav1.3 in OHCs. In OHCs from Cav1.3−/− mice, Ba2+ current density was reduced to 0.6 ± 0.5 pA pF−1 (n = 9) indicating that > 97 % of the Ca2+ channel current in OHCs flows through Cav1.3. PMID:14514878

  9. Cav1.3 (alpha1D) Ca2+ currents in neonatal outer hair cells of mice.

    PubMed

    Michna, Marcus; Knirsch, Martina; Hoda, Jean-Charles; Muenkner, Stefan; Langer, Patricia; Platzer, Josef; Striessnig, Jorg; Engel, Jutta

    2003-12-15

    Outer hair cells (OHC) serve as electromechanical amplifiers that guarantee the unique sensitivity and frequency selectivity of the mammalian cochlea. It is unknown whether the afferent fibres connected to adult OHCs are functional. If so, voltage-activated Ca2+ channels would be required for afferent synaptic transmission. In neonatal OHCs, Ca2+ channels seem to play a role in maturation since OHCs from Cav1.3-deficient (Cav1.3-/-) mice degenerate shortly after the onset of hearing. We therefore studied whole-cell Ca2+ currents in outer hair cells aged between postnatal day 1 (P1) and P8. OHCs showed a rapidly activating inward current that was 1.8 times larger with 10 mM Ba2+ as charge carrier (IBa) than with equimolar Ca2+ (ICa). IBa started activating at -50 mV with Vmax = -1.9 +/- 6.9 mV, V0.5 = -15.0 +/- 7.1 mV and k = 8.2 +/- 1.1 mV (n = 34). The peak IBa showed negligible inactivation (3.6 % after 300 ms) whereas the ICa (10 mM Ca2+) was inactivated by 50.7 %. OHC IBa was reduced by 33.5 +/- 10.3 % (n = 14) with 10 microM nifedipine and increased to 178.5 +/- 57.8 % (n = 14) by 5 microM Bay K 8644. A dose-response curve for nifedipine revealed an IC50 of 2.3 microM, a Hill coefficient of 2.7 and a maximum block of 36 %. Average IBa density in OHCs was 24.4 +/- 10.8 pA pF-1 (n = 105) which is only 38 % of the value in inner hair cells. Single cell RT-PCR revealed expression of Cav1.3 in OHCs. In OHCs from Cav1.3-/- mice, Ba2+ current density was reduced to 0.6 +/- 0.5 pA pF-1 (n = 9) indicating that > 97 % of the Ca2+ channel current in OHCs flows through Cav1.3. PMID:14514878

  10. How do the medial olivocochlear efferents influence the biomechanics of the outer hair cells and thereby the cochlear amplifier? Simulation results

    NASA Astrophysics Data System (ADS)

    Saremi, Amin; Stenfelt, Stefan; Verhulst, Sarah

    2015-12-01

    The bottom-up signal pathway, which starts from the outer ear and leads to the brain cortices, gives the classic image of the human sound perception. However, there have been growing evidences in the last six decades for existence of a functional descending network whereby the central auditory system can modulate the early auditory processing, in a top-down manner. The medial olivocochlear efferent fibers project from the superior olivary complex at the brainstem into the inner ear. They are linked to the basal poles of the hair cells by forming synaptic cisterns. This descending network can activate nicotinic cholinergic receptors (nAChR) that increase the membrane conductance of the outer hair cells and thereby modify the magnitude of the active force generated inside the cochlea. The aim of the presented work is to quantitatively investigate how the changes in the biomechanics of the outer hair cells, caused by the efferent activation, manipulate the cochlear responses. This is done by means of a frequency-domain biophysical model of the cochlea [12] where the parameters of the model convey physiological interpretations of the human cochlear structures. The simulations manifest that a doubling of the outer hair cell conductance, due to efferent activation, leads to a frequency-dependent gain reduction along the cochlear duct with its highest effect at frequencies between 1 kHz and 3.5 kHz and a maximum of approximately 10 dB gain reduction at 2 kHz. This amount of the gain inhibition and its frequency dependence reasonably agrees with the experimental data recorded from guinea pig, cat and human cochleae where the medial olivococlear efferents had been elicited by broad-band stimuli. The simulations also indicate that the efferent-induced increase of the outer hair cell conductance increases the best frequency of the cochlear responses, in the basal region. The presented simulations quantitatively confirm that activation of the medial olivocochlear efferents can

  11. Hair Growth Promotion Activity and Its Mechanism of Polygonum multiflorum

    PubMed Central

    Li, Yunfei; Han, Mingnuan; Lin, Pei; He, Yanran; Yu, Jie; Zhao, Ronghua

    2015-01-01

    Polygonum multiflorum Radix (PMR) has long history in hair growth promotion and hair coloring in clinical applications. However, several crucial problems in its clinic usage and mechanisms are still unsolved or lack scientific evidences. In this research, C57BL/6J mice were used to investigate hair growth promotion activity and possible mechanism of PMR and Polygonum multiflorum Radix Preparata (PMRP). Hair growth promotion activities were investigated by hair length, hair covered skin ratio, the number of follicles, and hair color. Regulation effects of several cytokines involved in the hair growth procedure were tested, such as fibroblast growth factor (FGF-7), Sonic Hedgehog (SHH), β-catenin, insulin-like growth factor-1 (IGF-1), and hepatocyte growth factor (HGF). Oral PMR groups had higher hair covered skin ratio (100 ± 0.00%) than oral PMRP groups (48%~88%). However, topical usage of PMRP had about 90% hair covered skin ratio. Both oral administration of PMR and topically given PMRP showed hair growth promotion activities. PMR was considered to be more suitable for oral administration, while PMRP showed greater effects in external use. The hair growth promotion effect of oral PMR was most probably mediated by the expression of FGF-7, while topical PMRP promoted hair growth by the stimulation of SHH expression. PMID:26294926

  12. Activating Hair Follicle Stem Cells via R-spondin2 to Stimulate Hair Growth.

    PubMed

    Smith, Andrew A; Li, Jingtao; Liu, Bo; Hunter, Daniel; Pyles, Malcolm; Gillette, Martin; Dhamdhere, Girija R; Abo, Arie; Oro, Anthony; Helms, Jill A

    2016-08-01

    Wnt signaling is required for the development of the hair follicle, and for inciting the growth (anagen) phase of the hair cycle. Most strategies to enhance Wnt signaling for hair growth create a state of constitutive Wnt activation, which leads to neoplastic transformation of the epithelial hair matrix. Using Axin2(LacZ/+) and Axin2(Cre/+)R26R(mTmG/+) reporter mice and RNA analyses, we show that Wnt signaling is elevated during anagen, is reduced at the onset of catagen, and can be reamplified in the skin and surrounding hair follicles via intradermal injection of recombinant R-spondin2 protein. Using Lgr5(LacZ/+) reporter mice, we demonstrate that this amplified Wnt environment leads to activation of leucine-rich repeat-containing G-protein coupled receptor 5-positive stem cells in the hair follicle. The onset of catagen is repressed by R-spondin2 injection, and the anagen phase persists. As a consequence, hair shafts grow longer. We conclude that R-spondin2 treatment activates hair follicle stem cells and therefore may have therapeutic potential to promote hair growth. PMID:27109869

  13. Cochlear Outer-Hair-Cell Power Generation and Viscous Fluid Loss.

    PubMed

    Wang, Yanli; Steele, Charles R; Puria, Sunil

    2016-01-01

    Since the discovery of otoacoustic emissions and outer hair cell (OHC) motility, the fundamental question of whether the cochlea produces mechanical power remains controversial. In the present work, direct calculations are performed on power loss due to fluid viscosity and power generated by the OHCs. A three-dimensional box model of the mouse cochlea is used with a feed-forward/feed-backward approximation representing the organ of Corti cytoarchitecture. The model is fit to in vivo basilar membrane motion with one free parameter for the OHCs. The calculations predict that the total power output from the three rows of OHCs can be over three orders of magnitude greater than the acoustic input power at 10 dB sound pressure level (SPL). While previous work shows that the power gain, or the negative damping, diminishes with intensity, we show explicitly based on our model that OHC power output increases and saturates with SPL. The total OHC power output is about 2 pW at 80 dB SPL, with a maximum of about 10 fW per OHC. PMID:26792556

  14. All Three Rows of Outer Hair Cells Are Required for Cochlear Amplification.

    PubMed

    Murakoshi, Michio; Suzuki, Sho; Wada, Hiroshi

    2015-01-01

    In the mammalian auditory system, the three rows of outer hair cells (OHCs) located in the cochlea are thought to increase the displacement amplitude of the organ of Corti. This cochlear amplification is thought to contribute to the high sensitivity, wide dynamic range, and sharp frequency selectivity of the hearing system. Recent studies have shown that traumatic stimuli, such as noise exposure and ototoxic acid, cause functional loss of OHCs in one, two, or all three rows. However, the degree of decrease in cochlear amplification caused by such functional losses remains unclear. In the present study, a finite element model of a cross section of the gerbil cochlea was constructed. Then, to determine effects of the functional losses of OHCs on the cochlear amplification, changes in the displacement amplitude of the basilar membrane (BM) due to the functional losses of OHCs were calculated. Results showed that the displacement amplitude of the BM decreases significantly when a single row of OHCs lost its function, suggesting that all three rows of OHCs are required for cochlear amplification. PMID:26295049

  15. A Langevin Model of Nanoelectromechanical Transduction in Cochlear Outer Hair Cells

    NASA Astrophysics Data System (ADS)

    Raphael, Robert M.

    2001-03-01

    Cochlear outer hair cells contribute to the sensitivity, frequency selectivity and dynamic range of mammalian hearing and are responsible for cochlea nonlinearities. We have developed a new model of this electromotility based on the statistical mechanics of freely rotating dipoles in a liquid crystalline membrane.^1 Voltage-induced dipole reorientation leads to extension of cytoskeletal filaments based on the nanostructral organization of the cell. The predictions of the model agree with electrophysiological data on the stationary noise characteristics of the membrane and with the absence of nonstationary shot noise. This indicates that the molecular events underlying high frequency electromotility involving stochastic diffusion of a voltage sensor in a potential of mean force. Evidence for order electricity comes from experiments revealing that the diffusion of fluorescent probes in the membrane depends on membrane potential and membrane tension, supporting the picture that electromechanical coupling involves a voltage-induced disorder-order transition within the membrane. ^1 Raphael, R. M., A. S. Popel and W. E. Brownell. 2000. Biophys. J. 78:2844

  16. Effects of common topical otic preparations on the morphology of isolated cochlear outer hair cells.

    PubMed

    Russell, P T; Church, C A; Jinn, T H; Kim, D J; John, E O; Jung, T T

    2001-01-01

    Otic drops are commonly used not only for otitis externa but also for otorrhea in the presence of tympanostomy tube or tympanic membrane perforation. Many studies have demonstrated the ototoxicity of common otic preparations such as Cortisporin otic drops. Recent studies have suggested the use of fluoroquinolone antibiotic drops as an alternative owing to their excellent antimicrobial coverage and no ototoxic effect. The purpose of this study was to assess the relative ototoxicity of four common otic preparations by direct exposure to isolated cochlear outer hair cells (OHCs). OHCs from adult chinchilla cochlea were exposed to standard bathing solution (control), Cortisporin, Cipro HC, Ciloxan, and Floxin. The cells were observed using an inverted microscope, and the images recorded in digital still-frame and video, and analyzed on the Image Pro-Plus 3.0 program. As measured by time to cell death and change in morphology of OHCs, Cortisporin was most toxic to OHCs. Among the fluoroquinolone drops, Floxin was more toxic than Ciloxan or Cipro HC. PMID:11349764

  17. Expression and function of channelrhodopsin 2 in mouse outer hair cells

    NASA Astrophysics Data System (ADS)

    Chen, Fangyi; Wu, Tao; Wilson, Teresa; Subhash, Hrebesh; Omelchenko, Irina; Bateschell, Michael; Wang, Lingyan; Brigande, John; Jiang, Zhi-Gen; Nuttall, Alfred

    2013-03-01

    Outer hair cell (OHC) is widely accepted as the origin of cochlear amplification, a mechanism that accounts for the extreme sensitivity of the mammalian hearing. The key process of cochlear amplification is the reverse transduction, where the OHC changes its length under electrical stimulation. In this study, we developed a method to modulate electro-mechanical transduction with an optogenetic approach based on channelrhodopsin 2 (ChR2), a direct lightactivated non-selective cation channel (NSCC). We specifically expressed ChR2 in mouse cochlea OHCs through in uterus injection of adenovirus vector with ChR2 in fusion with the fluorescent marker tdTomato. We also transfected ChR2(H134R), a point mutant of ChR2, with plasmid to an auditory cell line (HEI-OC1). With whole cell recording, we found that blue light (470 nm) elicited a current with a reversal potential around zero in both mouse OHCs and HEI-OC1 cells and generated depolarization in both cell types.

  18. Actuation of flexoelectric membranes in viscoelastic fluids with applications to outer hair cells.

    PubMed

    Herrera-Valencia, E E; Rey, Alejandro D

    2014-11-28

    Liquid crystal flexoelectric actuation uses an imposed electric field to create membrane bending, and it is used by the outer hair cells (OHCs) located in the inner ear, whose role is to amplify sound through generation of mechanical power. Oscillations in the OHC membranes create periodic viscoelastic flows in the contacting fluid media. A key objective of this work on flexoelectric actuation relevant to OHCs is to find the relations and impact of the electromechanical properties of the membrane, the rheological properties of the viscoelastic media, and the frequency response of the generated mechanical power output. The model developed and used in this work is based on the integration of: (i) the flexoelectric membrane shape equation applied to a circular membrane attached to the inner surface of a circular capillary and (ii) the coupled capillary flow of contacting viscoelastic phases, such that the membrane flexoelectric oscillations drive periodic viscoelastic capillary flows, as in OHCs. By applying the Fourier transform formalism to the governing equation, analytical expressions for the transfer function associated with the curvature and electrical field and for the power dissipation of elastic storage energy were found. PMID:25332388

  19. Cochlear outer hair cell bio-inspired metamaterial with negative effective parameters

    NASA Astrophysics Data System (ADS)

    Ma, Fuyin; Wu, Jiu Hui; Huang, Meng; Zhang, Siwen

    2016-05-01

    Inspired by periodical outer hair cells (OHCs) and stereocilia clusters of mammalian cochlear, a type of bio-inspired metamaterial with negative effective parameters based on the OHC structure is proposed. With the structural parameters modified and some common engineering materials adopted, the bio-inspired structure design with length scales of millimeter and lightweight is presented, and then, a bending wave bandgap in a favorable low-frequency with width of 55 Hz during the interval 21-76 or 116 Hz during the interval 57-173 Hz is obtained, i.e., the excellent low-frequency acoustic performance turns up. Compared with the local resonance unit in previous literatures, both the size and weight are greatly reduced in our bio-inspired structure. In addition, the lower edge of low-frequency bandgap is reduced by an order of magnitude, almost to the lower limit frequency of the hearing threshold as well, which achieves an important breakthrough on the aspect of low-frequency and great significance on the noise and vibration reduction in low-frequency range.

  20. Cochlear Outer-Hair-Cell Power Generation and Viscous Fluid Loss

    PubMed Central

    Wang, Yanli; Steele, Charles R.; Puria, Sunil

    2016-01-01

    Since the discovery of otoacoustic emissions and outer hair cell (OHC) motility, the fundamental question of whether the cochlea produces mechanical power remains controversial. In the present work, direct calculations are performed on power loss due to fluid viscosity and power generated by the OHCs. A three-dimensional box model of the mouse cochlea is used with a feed-forward/feed-backward approximation representing the organ of Corti cytoarchitecture. The model is fit to in vivo basilar membrane motion with one free parameter for the OHCs. The calculations predict that the total power output from the three rows of OHCs can be over three orders of magnitude greater than the acoustic input power at 10 dB sound pressure level (SPL). While previous work shows that the power gain, or the negative damping, diminishes with intensity, we show explicitly based on our model that OHC power output increases and saturates with SPL. The total OHC power output is about 2 pW at 80 dB SPL, with a maximum of about 10 fW per OHC. PMID:26792556

  1. Microdomains shift and rotate in the lateral wall of cochlear outer hair cells.

    PubMed

    Kitani, Rei; Park, Channy; Kalinec, Federico

    2013-01-01

    Outer hair cell (OHC) electromotility, a response consisting of reversible changes in cell length and diameter induced by electrical stimulation, confers remarkable sensitivity and frequency resolution to the mammalian inner ear. Looking for a better understanding of this mechanism, we labeled isolated guinea pig OHCs with microspheres and, using high-speed video recording, investigated their movements at the apical, mid, and basal regions of osmotically and electrically stimulated cells. After hypoosmotic challenge, OHCs shortened and their diameter increased, with microspheres moving always toward the central plane; iso-osmolarity returned OHCs to their original shape and microspheres to their original positions. Under electrical stimulation, microspheres exhibited robust movements, with their displacement vectors changing in direction from random to parallel to the longitudinal axis of the cells with peak reorientation speeds of up to 6 rad/s and returning to random after 5 min without stimulation. Alterations in plasma-membrane cholesterol levels as well as cytoskeleton integrity affected microsphere responses. We concluded that microspheres attach to different molecular microdomains, and these microdomains are able to shift and rotate in the plane of the OHC lateral wall with a dynamics tightly regulated by membrane lipid composition and the cortical cytoskeleton. PMID:23332054

  2. Mosaic pattern of Cre recombinase expression in cochlear outer hair cells of the Brn3.1 Cre mouse.

    PubMed

    Frenz, Silke; Rak, Kristen; Völker, Johannes; Jürgens, Lukas; Scherzad, Agmal; Schendzielorz, Philipp; Radeloff, Andreas; Jablonka, Sibylle; Hansen, Stefan; Mlynski, Robert; Hagen, Rudolf

    2015-04-15

    The Brn3.1 gene encodes for the protein Brn3.1, which is a member of the POU-IV class of transcription factors. Mutation leads to nonsyndromic human progressive hearing loss (DFNA15). To investigate the suitability of the Brn3.1 promoter for Cre recombinase-induced genetic recombination in cochlear hair cells, we established a transgenic Brn3.1 Cre mouse. This mouse line was crossbred with floxed ROSA26 and ROSA26 reporter mice. The cochleae were histologically analysed in cryosections at E16.5 and whole-mount preparations from P2 until P85. In addition, mice from all used strains and their recombinant offspring were tested electrophysiologically by auditory brainstem responses (ABR) and distorsion product otoacoustic emissions (DPOAE). Cre recombinase activity could be detected in P14 and P21 animals in a mosaic pattern in 26.3 and 9.9% of the outer hair cells, respectively. All investigated mice showed normal ABR and DPOAE values, indicating that neither insertion of the internal ribosome entry site (IRES) Cre cassette into the Brn3.1 gene led to abnormal auditory development nor did the reporter strains show inherited hearing disorders. This study shows that Cre expression under the control of the Brn3.1 promoter is feasible and that the insertion of the internal ribosome entry site Cre cassette into this locus exerted no effects on hearing development. Because of the inconstant pattern and the limited duration of expression, the application of the developed mouse line might be restricted. Also, the unchanged hearing capacity and structural integrity of the organ of Corti in available reporter lines indicate that they may be useful tools for hearing research. PMID:25714426

  3. Coordinated movement of the three rows of outer hair cells is essential for cochlear amplification

    NASA Astrophysics Data System (ADS)

    Murakoshi, Michio; Suzuki, Sho; Wada, Hiroshi

    2015-12-01

    The process known as cochlear amplification is realized by coordinated movement of the outer hair cells (OHCs) in response to changes in their membrane potential. In this process, the displacement amplitude of the basilar membrane (BM) is thought to be increased, thereby leading to the high sensitivity, wide dynamic range and sharp frequency selectivity of our hearing. Unfortunately, however, OHCs are vulnerable to noise exposure, ototoxic acid, aging and so on. Previous studies have shown that exposure to intense noise causes functional loss of OHCs from the innermost row (i.e., close to the modiolus) to the outermost row (i.e., close to the cochlear wall). On the contrary, by other traumatic stimuli such as ototoxic acid, aging and ischemia, such loss of OHCs has been reported to occur from the outermost row toward the innermost row. However, how the cochlear amplification changes when coordinated movement of OHCs is impaired, that is when the OHCs in one, two or all three rows have become dysfunctional, remains unclear. In the present study, therefore, a finite element (FE) model of the gerbil cochlea, which takes the motility of OHCs into account, was developed based on our previous FE model. Using this model, changes in the displacement amplitude of the BM due to the functional loss of OHCs in one, two or all three rows were investigated and the effects of incoordination of the three rows of OHCs on cochlear amplification were estimated. Results showed that the displacement amplitude of the BM significantly decreased when either the innermost row or the outermost row of OHCs lost its function, suggesting that all three rows of OHCs are required for cochlear amplification.

  4. From Zebrafish to Mammal: Functional Evolution of Prestin, the Motor Protein of Cochlear Outer Hair Cells

    PubMed Central

    Tan, Xiaodong; Pecka, Jason L.; Tang, Jie; Okoruwa, Oseremen E.; Zhang, Qian

    2011-01-01

    Prestin is the motor protein of cochlear outer hair cells. It belongs to a distinct anion transporter family called solute carrier protein 26A, or SLC26A. Members of this family serve two fundamentally distinct functions. Although most members transport different anion substrates across a variety of epithelia, prestin (SLC26A5) is unique, functioning as a voltage-dependent motor protein. Recent evidence suggests that prestin orthologs from zebrafish and chicken are electrogenic divalent/chloride anion exchangers/transporters with no motor function. These studies appear to suggest that prestin was evolved from an anion transporter. We examined the motor and transport functions of prestin and its orthologs from four different species in the vertebrate lineage, to gain insights of how these two physiological functions became distinct. Somatic motility, voltage-dependent nonlinear capacitance (NLC), and transporter function were measured in transfected human embryonic kidney (HEK) cells using voltage-clamp and anion uptake techniques. Zebrafish and chicken prestins both exhibited weak NLC, with peaks significantly shifted in the depolarization (right) direction. This was contrasted by robust NLC with peaks left shifted in the platypus and gerbil. The platypus and gerbil prestins retained little transporter function compared with robust anion transport capacities in the zebrafish and chicken orthologs. Somatic motility was detected only in the platypus and gerbil prestins. There appears to be an inverse relationship between NLC and anion transport functions, whereas motor function appears to have emerged only in mammalian prestin. Our results suggest that motor function is an innovation of therian prestin and is concurrent with diminished transporter capabilities. PMID:21047933

  5. From zebrafish to mammal: functional evolution of prestin, the motor protein of cochlear outer hair cells.

    PubMed

    Tan, Xiaodong; Pecka, Jason L; Tang, Jie; Okoruwa, Oseremen E; Zhang, Qian; Beisel, Kirk W; He, David Z Z

    2011-01-01

    Prestin is the motor protein of cochlear outer hair cells. It belongs to a distinct anion transporter family called solute carrier protein 26A, or SLC26A. Members of this family serve two fundamentally distinct functions. Although most members transport different anion substrates across a variety of epithelia, prestin (SLC26A5) is unique, functioning as a voltage-dependent motor protein. Recent evidence suggests that prestin orthologs from zebrafish and chicken are electrogenic divalent/chloride anion exchangers/transporters with no motor function. These studies appear to suggest that prestin was evolved from an anion transporter. We examined the motor and transport functions of prestin and its orthologs from four different species in the vertebrate lineage, to gain insights of how these two physiological functions became distinct. Somatic motility, voltage-dependent nonlinear capacitance (NLC), and transporter function were measured in transfected human embryonic kidney (HEK) cells using voltage-clamp and anion uptake techniques. Zebrafish and chicken prestins both exhibited weak NLC, with peaks significantly shifted in the depolarization (right) direction. This was contrasted by robust NLC with peaks left shifted in the platypus and gerbil. The platypus and gerbil prestins retained little transporter function compared with robust anion transport capacities in the zebrafish and chicken orthologs. Somatic motility was detected only in the platypus and gerbil prestins. There appears to be an inverse relationship between NLC and anion transport functions, whereas motor function appears to have emerged only in mammalian prestin. Our results suggest that motor function is an innovation of therian prestin and is concurrent with diminished transporter capabilities. PMID:21047933

  6. Synchronization of Spontaneous Active Motility of Hair Cell Bundles

    PubMed Central

    Zhang, Tracy-Ying; Ji, Seung; Bozovic, Dolores

    2015-01-01

    Hair cells of the inner ear exhibit an active process, believed to be crucial for achieving the sensitivity of auditory and vestibular detection. One of the manifestations of the active process is the occurrence of spontaneous hair bundle oscillations in vitro. Hair bundles are coupled by overlying membranes in vivo; hence, explaining the potential role of innate bundle motility in the generation of otoacoustic emissions requires an understanding of the effects of coupling on the active bundle dynamics. We used microbeads to connect small groups of hair cell bundles, using in vitro preparations that maintain their innate oscillations. Our experiments demonstrate robust synchronization of spontaneous oscillations, with either 1:1 or multi-mode phase-locking. The frequency of synchronized oscillation was found to be near the mean of the innate frequencies of individual bundles. Coupling also led to an improved regularity of entrained oscillations, demonstrated by an increase in the quality factor. PMID:26540409

  7. Synchronization of Spontaneous Active Motility of Hair Cell Bundles.

    PubMed

    Zhang, Tracy-Ying; Ji, Seung; Bozovic, Dolores

    2015-01-01

    Hair cells of the inner ear exhibit an active process, believed to be crucial for achieving the sensitivity of auditory and vestibular detection. One of the manifestations of the active process is the occurrence of spontaneous hair bundle oscillations in vitro. Hair bundles are coupled by overlying membranes in vivo; hence, explaining the potential role of innate bundle motility in the generation of otoacoustic emissions requires an understanding of the effects of coupling on the active bundle dynamics. We used microbeads to connect small groups of hair cell bundles, using in vitro preparations that maintain their innate oscillations. Our experiments demonstrate robust synchronization of spontaneous oscillations, with either 1:1 or multi-mode phase-locking. The frequency of synchronized oscillation was found to be near the mean of the innate frequencies of individual bundles. Coupling also led to an improved regularity of entrained oscillations, demonstrated by an increase in the quality factor. PMID:26540409

  8. Dissection of the Mechanical Impedance Components of the Outer Hair Cell Using a Chloride-Channel Blocker

    NASA Astrophysics Data System (ADS)

    Harasztosi, Csaba; Gummer, Anthony W.

    2011-11-01

    The voltage-dependent chloride-channel blocker anthracene-9-carboxylic acid (9AC) has been found to reduce the imaginary but not the real part of the mechanical impedance of the organ of Corti, suggesting that the effective stiffness of outer hair cells (OHCs) is reduced by 9AC. To examine whether 9AC interacts directly with the motor protein prestin to reduce the membrane component of the impedance, the patch-clamp technique in whole-cell configuration was used to measure the nonlinear capacitance (NLC) of isolated OHCs and, as control, prestin-transfected human embryonic kidney 293 (HEK293) cells. Extracellular application of 9AC significantly reduced the NLC of both OHCs and HEK293 cells. Intracellular 9AC did not influence the blocking effect of the extracellular applied drug. These results suggest that 9AC interacts directly with prestin, reducing the effective stiffness of the motor, and that the interaction is extracellular.

  9. Centering Perspectives on Black Women, Hair Politics, and Physical Activity

    PubMed Central

    Versey, H. Shellae

    2014-01-01

    As researchers categorize issues facing Black women’s health, obesity and physical exercise continue to be significant topics of debate. General interventions targeted toward Black women to address obesity and increase physical exercise have been largely ineffective. In this article, I situate the current public health discourse on obesity and related interventions within a sociocultural context of body appearance, with a specific focus on hair. Why do some African American women feel such strong ties to their hair that they will avoid exercise? What can be done to understand this phenomenon and address alternatives that may make both hair maintenance and regular exercise feasible? I map a theoretical argument for why hair matters for some women, and discuss how physical activity intervention strategies might be improved by considering such complexities. PMID:24625146

  10. Evaluation of hair growth promoting activity of Phyllanthus niruri

    PubMed Central

    Patel, Satish; Sharma, Vikas; S. Chauhan, Nagendra; Thakur, Mayank; Dixit, Vinod Kumar

    2015-01-01

    Objective: This study was designed to investigate the potential Phyllanthus niruri (P. niruri ) extracts in promotion of hair growth. Materials and Methods: Here, we studied the hair growth promoting activity of petroleum ether extract of P. niruri following its topical administration. Alopecia was induced in albino rats by subcutaneous administration of testosterone for 21 days. Evaluation of hair loss inhibition was done by concurrent administration of extract and monitoring parameters like follicular density, anagen/telogen (A/T) ratio and histological observation of animal skin sections. Finasteride solution was applied topically as standard. In vitro experiments were also performed to study the effect of extract on the activity of 5α-reductase enzyme Results: Groups treated with petroleum ether extract of plant showed hair re-growth as reflected by follicular density, A/T ratio and skin sections. Histopathology and morphologic observations of hair re-growth at shaved sites showed active follicular proliferation. In vitro experiments results showed inhibitory activity of petroleum ether extract on type-2 5α-reductase enzyme and an increase in the amount of testosterone with increasing concentrations. Conclusion: It could be concluded that petroleum ether extracts of P. niruri might be useful in the treatment of testosterone-induced alopecia in the experimental animal by inhibiting 5α-reductase enzyme. PMID:26693408

  11. [Neutron activation analysis of human hair--multivariate analysis of factors influencing on trace element contents in hair-- (author's transl)].

    PubMed

    Imahori, A; Fukushima, I

    1980-06-01

    As a part of IAEA research project, "Activation analysis of hair as an indicator of contamination of man by environmental trace element pollutants", a survey was carried out to elucidate the levels of various trace element concentrations in hair of local population in the Tokyo Metropolitan areas, by applying instrumental neutron activation analysis. A total of 202 scalp hair samples were collected from the inhabitants classified by sex and five age classes. Irradiation was made in the Rikkyo University 100 kW TRIGA MARK-II reactor. Using several combinations of irradiation time, cooling time and counting time, forty elements were determined. The relationship between several trace element contents in hair and such factors as sex, age class, hair treatment, smoking habit and dental treatment, was analyzed by using the method of multiple regression. It was shown that (1) Hair treatment had a predominant effect on the contents of bromine, magnesium and calcium in hair, (2) Aging and smoking contributed increasing mercury content in hair, and hair treatment acted reversely. PMID:7208973

  12. Dopamine Modulates the Activity of Sensory Hair Cells

    PubMed Central

    Toro, Cecilia; Trapani, Josef G.; Pacentine, Itallia; Maeda, Reo; Sheets, Lavinia; Mo, Weike

    2015-01-01

    The senses of hearing and balance are subject to modulation by efferent signaling, including the release of dopamine (DA). How DA influences the activity of the auditory and vestibular systems and its site of action are not well understood. Here we show that dopaminergic efferent fibers innervate the acousticolateralis epithelium of the zebrafish during development but do not directly form synapses with hair cells. However, a member of the D1-like receptor family, D1b, tightly localizes to ribbon synapses in inner ear and lateral-line hair cells. To assess modulation of hair-cell activity, we reversibly activated or inhibited D1-like receptors (D1Rs) in lateral-line hair cells. In extracellular recordings from hair cells, we observed that D1R agonist SKF-38393 increased microphonic potentials, whereas D1R antagonist SCH-23390 decreased microphonic potentials. Using ratiometric calcium imaging, we found that increased D1R activity resulted in larger calcium transients in hair cells. The increase of intracellular calcium requires Cav1.3a channels, as a Cav1 calcium channel antagonist, isradipine, blocked the increase in calcium transients elicited by the agonist SKF-38393. Collectively, our results suggest that DA is released in a paracrine fashion and acts at ribbon synapses, likely enhancing the activity of presynaptic Cav1.3a channels and thereby increasing neurotransmission. SIGNIFICANCE STATEMENT The neurotransmitter dopamine acts in a paracrine fashion (diffusion over a short distance) in several tissues and bodily organs, influencing and regulating their activity. The cellular target and mechanism of the action of dopamine in mechanosensory organs, such as the inner ear and lateral-line organ, is not clearly understood. Here we demonstrate that dopamine receptors are present in sensory hair cells at synaptic sites that are required for signaling to the brain. When nearby neurons release dopamine, activation of the dopamine receptors increases the activity of

  13. Apamin-sensitive, small-conductance, calcium-activated potassium channels mediate cholinergic inhibition of chick auditory hair cells.

    PubMed

    Yuhas, W A; Fuchs, P A

    1999-11-01

    Acetylcholine released from efferent neurons in the cochlea causes inhibition of mechanosensory hair cells due to the activation of calcium-dependent potassium channels. Hair cells are known to have large-conductance, "BK"-type potassium channels associated with the afferent synapse, but these channels have different properties than those activated by acetylcholine. Whole-cell (tight-seal) and cell-attached patch-clamp recordings were made from short (outer) hair cells isolated from the chicken basilar papilla (cochlea equivalent). The peptides apamin and charybdotoxin were used to distinguish the calcium-activated potassium channels involved in the acetylcholine response from the BK-type channels associated with the afferent synapse. Differential toxin blockade of these potassium currents provides definitive evidence that ACh activates apamin-sensitive, "SK"-type potassium channels, but does not activate carybdotoxin-sensitive BK channels. This conclusion is supported by tentative identification of small-conductance, calcium-sensitive but voltage-insensitive potassium channels in cell-attached patches. The distinction between these channel types is important for understanding the segregation of opposing afferent and efferent synaptic activity in the hair cell, both of which depend on calcium influx. These different calcium-activated potassium channels serve as sensitive indicators for functionally significant calcium influx in the hair cell. PMID:10573868

  14. Mitochondrial aerobic respiration is activated during hair follicle stem cell differentiation, and its dysfunction retards hair regeneration.

    PubMed

    Tang, Yan; Luo, Binping; Deng, Zhili; Wang, Ben; Liu, Fangfen; Li, Jinmao; Shi, Wei; Xie, Hongfu; Hu, Xingwang; Li, Ji

    2016-01-01

    Background. Emerging research revealed the essential role of mitochondria in regulating stem/progenitor cell differentiation of neural progenitor cells, mesenchymal stem cells and other stem cells through reactive oxygen species (ROS), Notch or other signaling pathway. Inhibition of mitochondrial protein synthesis results in hair loss upon injury. However, alteration of mitochondrial morphology and metabolic function during hair follicle stem cells (HFSCs) differentiation and how they affect hair regeneration has not been elaborated upon. Methods. We compared the difference in mitochondrial morphology and activity between telogen bulge cells and anagen matrix cells. Expression levels of mitochondrial ROS and superoxide dismutase 2 (SOD2) were measured to evaluate redox balance. In addition, the level of pyruvate dehydrogenase kinase (PDK) and pyruvate dehydrogenase (PDH) were estimated to present the change in energetic metabolism during differentiation. To explore the effect of the mitochondrial metabolism on regulating hair regeneration, hair growth was observed after application of a mitochondrial respiratory inhibitor upon hair plucking. Results. During HFSCs differentiation, mitochondria became elongated with more abundant organized cristae and showed higher activity in differentiated cells. SOD2 was enhanced for redox balance with relatively stable ROS levels in differentiated cells. PDK increased in HFSCs while differentiated cells showed enhanced PDH, indicating that respiration switched from glycolysis to oxidative phosphorylation during differentiation. Inhibiting mitochondrial respiration in differentiated hair follicle cells upon hair plucking repressed hair regeneration in vivo. Conclusions. Upon HFSCs differentiation, mitochondria are elongated with more abundant cristae and show higher activity, accompanying with activated aerobic respiration in differentiated cells for higher energy supply. Also, dysfunction of mitochondrial respiration delays hair

  15. Mitochondrial aerobic respiration is activated during hair follicle stem cell differentiation, and its dysfunction retards hair regeneration

    PubMed Central

    Tang, Yan; Luo, Binping; Deng, Zhili; Wang, Ben; Liu, Fangfen; Li, Jinmao; Shi, Wei; Xie, Hongfu; Hu, Xingwang

    2016-01-01

    Background. Emerging research revealed the essential role of mitochondria in regulating stem/progenitor cell differentiation of neural progenitor cells, mesenchymal stem cells and other stem cells through reactive oxygen species (ROS), Notch or other signaling pathway. Inhibition of mitochondrial protein synthesis results in hair loss upon injury. However, alteration of mitochondrial morphology and metabolic function during hair follicle stem cells (HFSCs) differentiation and how they affect hair regeneration has not been elaborated upon. Methods. We compared the difference in mitochondrial morphology and activity between telogen bulge cells and anagen matrix cells. Expression levels of mitochondrial ROS and superoxide dismutase 2 (SOD2) were measured to evaluate redox balance. In addition, the level of pyruvate dehydrogenase kinase (PDK) and pyruvate dehydrogenase (PDH) were estimated to present the change in energetic metabolism during differentiation. To explore the effect of the mitochondrial metabolism on regulating hair regeneration, hair growth was observed after application of a mitochondrial respiratory inhibitor upon hair plucking. Results. During HFSCs differentiation, mitochondria became elongated with more abundant organized cristae and showed higher activity in differentiated cells. SOD2 was enhanced for redox balance with relatively stable ROS levels in differentiated cells. PDK increased in HFSCs while differentiated cells showed enhanced PDH, indicating that respiration switched from glycolysis to oxidative phosphorylation during differentiation. Inhibiting mitochondrial respiration in differentiated hair follicle cells upon hair plucking repressed hair regeneration in vivo. Conclusions. Upon HFSCs differentiation, mitochondria are elongated with more abundant cristae and show higher activity, accompanying with activated aerobic respiration in differentiated cells for higher energy supply. Also, dysfunction of mitochondrial respiration delays hair

  16. Susceptibility of outer hair cells to cholesterol chelator 2-hydroxypropyl-β-cyclodextrine is prestin-dependent.

    PubMed

    Takahashi, Satoe; Homma, Kazuaki; Zhou, Yingjie; Nishimura, Shinichi; Duan, Chongwen; Chen, Jessie; Ahmad, Aisha; Cheatham, Mary Ann; Zheng, Jing

    2016-01-01

    Niemann-Pick type C1 disease (NPC1) is a fatal genetic disorder caused by impaired intracellular cholesterol trafficking. Recent studies reported ototoxicity of 2-hydroxypropyl- β-cyclodextrin (HPβCD), a cholesterol chelator and the only promising treatment for NPC1. Because outer hair cells (OHCs) are the only cochlear cells affected by HPβCD, we investigated whether prestin, an OHC-specific motor protein, might be involved. Single, high-dose administration of HPβCD resulted in OHC death in prestin wildtype (WT) mice whereas OHCs were largely spared in prestin knockout (KO) mice in the basal region, implicating prestin's involvement in ototoxicity of HPβCD. We found that prestin can interact with cholesterol in vitro, suggesting that HPβCD-induced ototoxicity may involve disruption of this interaction. Time-lapse analysis revealed that OHCs isolated from WT animals rapidly deteriorated upon HPβCD treatment while those from prestin-KOs tolerated the same regimen. These results suggest that a prestin-dependent mechanism contributes to HPβCD ototoxicity. PMID:26903308

  17. Susceptibility of outer hair cells to cholesterol chelator 2-hydroxypropyl-β-cyclodextrine is prestin-dependent

    PubMed Central

    Takahashi, Satoe; Homma, Kazuaki; Zhou, Yingjie; Nishimura, Shinichi; Duan, Chongwen; Chen, Jessie; Ahmad, Aisha; Cheatham, Mary Ann; Zheng, Jing

    2016-01-01

    Niemann-Pick type C1 disease (NPC1) is a fatal genetic disorder caused by impaired intracellular cholesterol trafficking. Recent studies reported ototoxicity of 2-hydroxypropyl- β-cyclodextrin (HPβCD), a cholesterol chelator and the only promising treatment for NPC1. Because outer hair cells (OHCs) are the only cochlear cells affected by HPβCD, we investigated whether prestin, an OHC-specific motor protein, might be involved. Single, high-dose administration of HPβCD resulted in OHC death in prestin wildtype (WT) mice whereas OHCs were largely spared in prestin knockout (KO) mice in the basal region, implicating prestin’s involvement in ototoxicity of HPβCD. We found that prestin can interact with cholesterol in vitro, suggesting that HPβCD-induced ototoxicity may involve disruption of this interaction. Time-lapse analysis revealed that OHCs isolated from WT animals rapidly deteriorated upon HPβCD treatment while those from prestin-KOs tolerated the same regimen. These results suggest that a prestin-dependent mechanism contributes to HPβCD ototoxicity. PMID:26903308

  18. Relationship between urokinase plasminogen activator receptor (uPAR) and the invasion of human prenatal hair follicle.

    PubMed

    Gao, Qiangguo; Fu, Gang; Huang, Gang; Lian, Xiaohua; Yu, Jin; Yang, Tian

    2010-08-01

    During the morphogenesis of hair follicles, the invasive migration of basal keratinocytes resembles cell's dissemination of tissue remodeling. The urokinase-type plasminogen activator receptor (uPAR) appears to be a key molecule in the metastasis. In order to elucidate the relationship between uPAR and the invasion of the human hair follicle, immunohistochemistry, RT-PCR, plasmids transfection, and western blot were used. The results showed that uPAR was expressed in the outermost epithelial cells of the hair follicle and the basal keratinocytes of epidermis, and that the expression decreased with the development of the hair follicle. The cells of the outer root sheath (ORS) and interfollicle epidermis, which overexpressed uPAR, acquired increased invasiveness; however, they showed decreased invasion with overexpression of the urokinase-type plasminogen activator amino terminal fragment (uPA ATF), which inhibited the combination of uPAR and uPA competitively, and the cell invasive migration with overexpressed uPAR was required activated extracellular signal-regulated kinases (ERK). These results implied that overexpression of uPAR promote the invasive migration of hair follicle into the dermis in uPA-dependent and independent manner during human prenatal development. PMID:20012874

  19. Developing an active artificial hair cell using nonlinear feedback control

    NASA Astrophysics Data System (ADS)

    Joyce, Bryan S.; Tarazaga, Pablo A.

    2015-09-01

    The hair cells in the mammalian cochlea convert sound-induced vibrations into electrical signals. These cells have inspired a variety of artificial hair cells (AHCs) to serve as biologically inspired sound, fluid flow, and acceleration sensors and could one day replace damaged hair cells in humans. Most of these AHCs rely on passive transduction of stimulus while it is known that the biological cochlea employs active processes to amplify sound-induced vibrations and improve sound detection. In this work, an active AHC mimics the active, nonlinear behavior of the cochlea. The AHC consists of a piezoelectric bimorph beam subjected to a base excitation. A feedback control law is used to reduce the linear damping of the beam and introduce a cubic damping term which gives the AHC the desired nonlinear behavior. Model and experimental results show the AHC amplifies the response due to small base accelerations, has a higher frequency sensitivity than the passive system, and exhibits a compressive nonlinearity like that of the mammalian cochlea. This bio-inspired accelerometer could lead to new sensors with lower thresholds of detection, improved frequency sensitivities, and wider dynamic ranges.

  20. Instrumental neutron activation analysis of sectioned hair strands for arsenic

    SciTech Connect

    Guinn, V.P.

    1996-12-31

    Instrumental neutron activation analysis (INAA) is a valuable and proven method for the quantitative analysis of sectioned human head hair specimens for arsenic - and, if arsenic is found to be present at high concentrations, the approximate times when it was ingested. Reactor-flux thermal-neutron activation of the hair samples produces 26.3-h {sup 76}As, which is then detected by germanium gamma-ray spectrometry, measuring the 559.1-keV gamma-ray peak of {sup 76}As. Even normal levels of arsenic in hair, in the range of <1 ppm up to a few parts per million of arsenic can be measured - and the far higher levels associated with large internal doses of arsenic, levels approaching or exceeding 100 ppm arsenic, are readily and accurately measurable. However, all phases of forensic investigations of possible chronic (or in some cases, acute) arsenic poisoning are important, i.e., not just the analysis phase. All of these phases are discussed in this paper, based on the author`s experience and the experience of others, in criminal cases. Cases of chronic arsenic poisoning often reveal a series of two to four doses, perhaps a few months apart, with increasing doses.

  1. Protease activity, localization and inhibition in the human hair follicle

    PubMed Central

    Bhogal, R K; Mouser, P E; Higgins, C A; Turner, G A

    2014-01-01

    Synopsis Objective In humans, the process of hair shedding, referred to as exogen, is believed to occur independently of the other hair cycle phases. Although the actual mechanisms involved in hair shedding are not fully known, it has been hypothesized that the processes leading to the final step of hair shedding may be driven by proteases and/or protease inhibitor activity. In this study, we investigated the presence of proteases and protease activity in naturally shed human hairs and assessed enzyme inhibition activity of test materials. Methods We measured enzyme activity using a fluorescence-based assay and protein localization by indirect immunohistochemistry (IHC). We also developed an ex vivo skin model for measuring the force required to pull hair fibres from skin. Results Our data demonstrate the presence of protease activity in the tissue material surrounding club roots. We also demonstrated the localization of specific serine protease protein expression in human hair follicle by IHC. These data provide evidence demonstrating the presence of proteases around the hair club roots, which may play a role during exogen. We further tested the hypothesis that a novel protease inhibitor system (combination of Trichogen® and climbazole) could inhibit protease activity in hair fibre club root extracts collected from a range of ethnic groups (UK, Brazil, China, first-generation Mexicans in the USA, Thailand and Turkey) in both males and females. Furthermore, we demonstrated that this combination is capable of increasing the force required to remove hair in an ex vivo skin model system. Conclusion These studies indicate the presence of proteolytic activity in the tissue surrounding the human hair club root and show that it is possible to inhibit this activity with a combination of Trichogen® and climbazole. This technology may have potential to reduce excessive hair shedding. Résumé Objectif Chez l'homme, le processus de perte de cheveux, désigné comme exog

  2. Acetylcholine-induced potassium current of guinea pig outer hair cells: its dependence on a calcium influx through nicotinic-like receptors.

    PubMed

    Blanchet, C; Eróstegui, C; Sugasawa, M; Dulon, D

    1996-04-15

    The cholinergic efferent inhibition of mammalian outer hair cells (OHCs) is mediated by a hyperpolarizing K+ current. We have made whole-cell tight-seal recordings from single OHCs isolated from the guinea pig cochlea to characterize the mechanism by which acetylcholine (ACh) activates K+ channels. After ACh application, OHCs exhibited a biphasic response: an early depolarizing current preceding the predominant hyperpolarizing K+ current. The current-voltage (I-V) relationship of the ACh-induced response displayed an N-shape, suggesting the involvement of Ca2+ influx. When whole-cell recording was combined with confocal calcium imaging, we simultaneously observed the ACh-induced K+ current (IK(ACh)) and a Ca2+ response restricted to the synaptic area of the cell. This IK(ACh) could be prevented by loading OHCs with 10 mM of the fast Ca2+ buffer bis(2-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid (or BAPTA), therefore allowing the observation of the ACh-induced early current in isolation. This early current revealed nicotinic features because it activated with an intrinsic delay in the millisecond range, reversed nearly in between potassium and sodium equilibrium potentials, and was blocked by curare. However, it was strongly reduced in the absence of external Ca2+, and its I-V relationship displayed an unusual outward rectification at positive membrane potentials and an inward rectification below -60 mV. The results indicate that the cholinergic response of mammalian OHCs involves a "nicotinic-like" nonspecific cation channel through which Ca2+ enters and triggers activation of nearby Ca2+-dependent K+ channels. PMID:8786433

  3. Characterization of active hair-bundle motility by a mechanical-load clamp

    NASA Astrophysics Data System (ADS)

    Salvi, Joshua D.; Maoiléidigh, Dáibhid Ó.; Fabella, Brian A.; Tobin, Mélanie; Hudspeth, A. J.

    2015-12-01

    Active hair-bundle motility endows hair cells with several traits that augment auditory stimuli. The activity of a hair bundle might be controlled by adjusting its mechanical properties. Indeed, the mechanical properties of bundles vary between different organisms and along the tonotopic axis of a single auditory organ. Motivated by these biological differences and a dynamical model of hair-bundle motility, we explore how adjusting the mass, drag, stiffness, and offset force applied to a bundle control its dynamics and response to external perturbations. Utilizing a mechanical-load clamp, we systematically mapped the two-dimensional state diagram of a hair bundle. The clamp system used a real-time processor to tightly control each of the virtual mechanical elements. Increasing the stiffness of a hair bundle advances its operating point from a spontaneously oscillating regime into a quiescent regime. As predicted by a dynamical model of hair-bundle mechanics, this boundary constitutes a Hopf bifurcation.

  4. Foxi3 Deficiency Compromises Hair Follicle Stem Cell Specification and Activation.

    PubMed

    Shirokova, Vera; Biggs, Leah C; Jussila, Maria; Ohyama, Takahiro; Groves, Andrew K; Mikkola, Marja L

    2016-07-01

    The hair follicle is an ideal system to study stem cell specification and homeostasis due to its well characterized morphogenesis and stereotypic cycles of stem cell activation upon each hair cycle to produce a new hair shaft. The adult hair follicle stem cell niche consists of two distinct populations, the bulge and the more activation-prone secondary hair germ (HG). Hair follicle stem cells are set aside during early stages of morphogenesis. This process is known to depend on the Sox9 transcription factor, but otherwise the establishment of the hair follicle stem cell niche is poorly understood. Here, we show that that mutation of Foxi3, a Forkhead family transcription factor mutated in several hairless dog breeds, compromises stem cell specification. Further, loss of Foxi3 impedes hair follicle downgrowth and progression of the hair cycle. Genome-wide profiling revealed a number of downstream effectors of Foxi3 including transcription factors with a recognized function in hair follicle stem cells such as Lhx2, Runx1, and Nfatc1, suggesting that the Foxi3 mutant phenotype results from simultaneous downregulation of several stem cell signature genes. We show that Foxi3 displays a highly dynamic expression pattern during hair morphogenesis and cycling, and identify Foxi3 as a novel secondary HG marker. Absence of Foxi3 results in poor hair regeneration upon hair plucking, and a sparse fur phenotype in unperturbed mice that exacerbates with age, caused by impaired secondary HG activation leading to progressive depletion of stem cells. Thus, Foxi3 regulates multiple aspects of hair follicle development and homeostasis. Stem Cells 2016;34:1896-1908. PMID:26992132

  5. Two Adaptation Processes in Auditory Hair Cells Together Can Provide an Active Amplifier

    PubMed Central

    Vilfan, Andrej; Duke, Thomas

    2003-01-01

    The hair cells of the vertebrate inner ear convert mechanical stimuli to electrical signals. Two adaptation mechanisms are known to modify the ionic current flowing through the transduction channels of the hair bundles: a rapid process involves Ca2+ ions binding to the channels; and a slower adaptation is associated with the movement of myosin motors. We present a mathematical model of the hair cell which demonstrates that the combination of these two mechanisms can produce “self-tuned critical oscillations”, i.e., maintain the hair bundle at the threshold of an oscillatory instability. The characteristic frequency depends on the geometry of the bundle and on the Ca2+ dynamics, but is independent of channel kinetics. Poised on the verge of vibrating, the hair bundle acts as an active amplifier. However, if the hair cell is sufficiently perturbed, other dynamical regimes can occur. These include slow relaxation oscillations which resemble the hair bundle motion observed in some experimental preparations. PMID:12829475

  6. Runx1 modulates developmental, but not injury-driven, hair follicle stem cell activation.

    PubMed

    Osorio, Karen M; Lee, Song Eun; McDermitt, David J; Waghmare, Sanjeev K; Zhang, Ying V; Woo, Hyun Nyun; Tumbar, Tudorita

    2008-03-01

    Aml1/Runx1 controls developmental aspects of several tissues, is a master regulator of blood stem cells, and plays a role in leukemia. However, it is unclear whether it functions in tissue stem cells other than blood. Here, we have investigated the role of Runx1 in mouse hair follicle stem cells by conditional ablation in epithelial cells. Runx1 disruption affects hair follicle stem cell activation, but not their maintenance, proliferation or differentiation potential. Adult mutant mice exhibit impaired de novo production of hair shafts and all temporary hair cell lineages, owing to a prolonged quiescent phase of the first hair cycle. The lag of stem cell activity is reversed by skin injury. Our work suggests a degree of functional overlap in Runx1 regulation of blood and hair follicle stem cells at an equivalent time point in the development of these two tissues. PMID:18256199

  7. Active Motion of Hair Bundles Coupled to the Otolithic Membrane in the Frog Sacculus

    NASA Astrophysics Data System (ADS)

    Strimbu, C. Elliott; Fredrickson-Hemsing, Lea; Bozovic, Dolores

    2011-11-01

    Active hair bundle motility has been proposed to provide the basis for the active process in the auditory organs of non-mammalian vertibrates, and has been extensively studied in mechanically decoupled or free-standing hair bundles from in vitro preparations of the frog sacculus. A number of studies have, however, suggested that cooperativity between hair cells plays an important role in the response of an intact organ. We use a semi-intact in vitro saccular preparation in which the hair cells are coupled and loaded by the otolithic membrane. While the hair bundles do not spontaneously oscillate beneath the membrane, they exhibit active movements in response to transient stimuli, demonstrating that the active process remains operant under these conditions. The coupled system however displays a striking decrease in frequency selectivity compared to freely oscillating bundles.

  8. Developmental and activity-dependent plasticity of filiform hair receptors in the locust

    PubMed Central

    Pflüger, Hans-Joachim; Wolf, Harald

    2013-01-01

    A group of wind sensitive filiform hair receptors on the locust thorax and head makes contact onto a pair of identified interneuron, A4I1. The hair receptors' central nervous projections exhibit pronounced structural dynamics during nymphal development, for example, by gradually eliminating their ipsilateral dendritic field while maintaining the contralateral one. These changes are dependent not only on hormones controlling development but on neuronal activity as well. The hair-to-interneuron system has remarkably high gain (close to 1) and makes contact to flight steering muscles. During stationary flight in front of a wind tunnel, interneuron A4I1 is active in the wing beat rhythm, and in addition it responds strongly to stimulation of sensory hairs in its receptive field. A role of the hair-to-interneuron in flight steering is thus suggested. This system appears suitable for further study of developmental and activity-dependent plasticity in a sensorimotor context with known connectivity patterns. PMID:23986712

  9. Radiolead (210)Pb and (210)Po/(210)Pb activity ratios in dogs' hair.

    PubMed

    Strumińska-Parulska, Dagmara I; Szymańska, Karolina; Skwarzec, Bogdan

    2015-01-01

    The aim of this study was to determine activity concentrations of radiolead (210)Pb as well as (210)Po/(210)Pb activity ratios in dog hair. The objectives of this research were also to investigate the utility of domestic animal hair as a noninvasive indicator of metal exposure for radiotoxic, naturally occurring (210)Pb and find the correlations between (210)Pb concentration in hair and age, gender, hair type or diet of analyzed animals. The highest (210)Pb concentrations were measured in a 2-year-old Shih Tzus (9.82 ± 0.53 Bq kg(-1) dw(-1)) and a 2-year-old Bichon Maltese (8.09 ± 0.42 Bq kg(-1) dw(-1)), both longhair males, while the lowest was found in a 15-year-old Yorkshire Terrier (0.44 ± 0.02 Bq kg(-1) dw(-1)), small longhair male as well. As results showed, mainly dog hair color as well as their age and gender influenced the differences in the values of (210)Pb concentrations in analyzed hair samples. Also the values of activity ratios of (210)Po/(210)Pb in analyzed dog hair samples were calculated and obtained results were similar to those observed in human hair. PMID:26191992

  10. Inhibition of Notch activity promotes nonmitotic regeneration of hair cells in the adult mouse utricles.

    PubMed

    Lin, Vincent; Golub, Justin S; Nguyen, Tot Bui; Hume, Clifford R; Oesterle, Elizabeth C; Stone, Jennifer S

    2011-10-26

    The capacity of adult mammals to regenerate sensory hair cells is not well defined. To explore early steps in this process, we examined reactivation of a transiently expressed developmental gene, Atoh1, in adult mouse utricles after neomycin-induced hair cell death in culture. Using an adenoviral reporter for Atoh1 enhancer, we found that Atoh1 transcription is activated in some hair cell progenitors (supporting cells) 3 d after neomycin treatment. By 18 d after neomycin, the number of cells with Atoh1 transcriptional activity increased significantly, but few cells acquired hair cell features (i.e., accumulated ATOH1 or myosin VIIa protein or developed stereocilia). Treatment with DAPT, an inhibitor of γ-secretase, reduced notch pathway activity, enhanced Atoh1 transcriptional activity, and dramatically increased the number of Atoh1-expressing cells with hair cell features, but only in the striolar/juxtastriolar region. Similar effects were seen with TAPI-1, an inhibitor of another enzyme required for notch activity (TACE). Division of supporting cells was rare in any control or DAPT-treated utricles. This study shows that mature mammals have a natural capacity to initiate vestibular hair cell regeneration and suggests that regional notch activity is a significant inhibitor of direct transdifferentiation of supporting cells into hair cells following damage. PMID:22031879

  11. Premature Graying as a Consequence of Compromised Antioxidant Activity in Hair Bulb Melanocytes and Their Precursors

    PubMed Central

    Shi, Ying; Luo, Long-Fei; Liu, Xiao-Ming; Zhou, Qiong; Xu, Shi-Zheng; Lei, Tie-Chi

    2014-01-01

    Intricate coordinated mechanisms that govern the synchrony of hair growth and melanin synthesis remain largely unclear. These two events can be uncoupled in prematurely gray hair, probably due to oxidative insults that lead to the death of oxidative stress-sensitive melanocytes. In this study, we examined the gene expression profiles of middle (bulge) and lower (hair bulb) segments that had been micro-dissected from unpigmented and from normally pigmented hair follicles from the same donors using quantitative real-time RT-PCR (qPCR) arrays. We found a significant down-regulation of melanogenesis-related genes (TYR, TYRP1, MITF, PAX3, POMC) in unpigmented hair bulbs and of marker genes typical for melanocyte precursor cells (PAX3, SOX10, DCT) in unpigmented mid-segments compared with their pigmented analogues. qPCR, western blotting and spin trapping assays revealed that catalase protein expression and hydroxyl radical scavenging activities are strongly repressed in unpigmented hair follicles. These data provide the first clear evidence that compromised antioxidant activity in gray hair follicles simultaneously affects mature hair bulb melanocytes and their immature precursor cells in the bulge region. PMID:24695442

  12. Sensitivity of quasi-periodic outer rainband activity of tropical cyclones to the surface entropy flux

    NASA Astrophysics Data System (ADS)

    Li, Qingqing; Duan, Yihong

    2013-10-01

    The influence of outer-core surface entropy fluxes (SEFs) on tropical cyclone (TC) outer rainband activity is investigated in this study with a fully compressible, nonhydrostatic model. A control simulation and two sensitivity experiments with the outer-core SEF artificially increased and decreased by 20% respectively were conducted to examine the quasi-periodic outer rainband behavior. Larger negative horizontal advection due to the greater radial wind and the positive contribution by asymmetric eddies leads to a longer period of outerrainband activity in the SEF-enhanced experiment. The well-developed outer rainbands in the control and SEF-reduced simulations significantly limit the TC intensity, whereas such an intensity suppression influence is not pronounced in the SEF-enhanced experiment. As diabatic heating in outer rainbands strengthens the outer-core tangential wind, the quasi-periodic activity of outer rainbands contributes to the quasi-periodic variations of the inner-core size of the TCs.

  13. Telomerase activity concentrates in the mitotically active segments of human hair follicles.

    PubMed

    Ramirez, R D; Wright, W E; Shay, J W; Taylor, R S

    1997-01-01

    Telomerase is a ribonucleoprotein enzyme capable of adding hexanucleotide repeats onto the ends of linear chromosomal DNA. Whereas normal somatic cells with a limited replicative capacity fail to express telomerase activity, most immortal eukaryotic cells do. Cells of renewal tissues (e.g., skin, intestine, blood) require an extensive proliferative capacity. Some cells in such renewal tissues also express telomerase activity, most likely to prevent rapid erosion of their telomeres during cell proliferation. In this study, we measured the levels of telomerase activity in dissected compartments of the human hair follicle: hair shaft, gland-containing fragment, upper intermediate fragment (where it is thought undifferentiated stem cells reside), lower intermediate fragment, and in the bulb-containing fragment (an area with high mitotic activity containing a more differentiated pool of keratinocytes). In anagen follicles, high levels of telomerase activity were found almost exclusively in the bulb-containing fragment of the follicles, with low levels of telomerase in the bulge area (intermediate fragments) and gland-containing fragment. In comparison, catagen follicles had low levels of telomerase activity in the bulb-containing fragments as well as in other compartments. Such observations indicate that, in anagen hair follicles, the fragments containing cells actively dividing (e.g., transient amplifying cells) express telomerase activity, whereas fragments containing cells with low mitotic activity, for example, quiescent stem cells, express low levels of telomerase activity. PMID:8980299

  14. Effect of photoperiod on reproductive activity and hair in mares.

    PubMed

    Kooistra, L H; Ginther, O J

    1975-10-01

    The effects of photoperiod on reproductive activity and hair changes in pony mares were studied in 2 experiments. In experiment I, the effect of a fixed daily photoperiod on the onset of the breeding season was studied in 36 mares from Nov 13, 1973, to June 13, 1974. The 4 treatment groups were as follows: daily photoperiod equivalent to the normal day length (control group); constant light 24 hours a day with no dark (L24:D0 group); 16-hour daily photoperiod with 8 hours of dark (L16:D8 group); and 9-hour daily photoperiod with 15 hours of dark (L9:D15 group). The intervals from beginning of experiment to 1st ovulation of breeding season, to shedding of hair in tufts, and to appearance of a smooth coat were shorter (P less than 0.05) for L16:D8 group (107.1 +/- 11.1, 56.0 +/- 0, and 145.8 +/- 4.0 days, respectively) than for control, L24:D0, and L9:D15 groups and were shorter (P less than 0.05) for L24:D0 group (less than 156.1 +/- 12.2, 99.5 +/- 9.5, and 173.9 +/- 9.9 days, respectively) than for control group (192.1 +/- 3.3, 134.9 +/- 8.9, and 205.0 +/- 0 days, respectively) or L9:D15 group (less than 200.3 +/- 5,8, 150.6 +/- 12.9, and 201.7 +/- 3.3 days, respectively). These intervals were not significantly different between the control group and the L9:D15 group, but fewer (P less than 0.05) mares in the L9:D15 group had at least 1 ovulation by termination of the project. In experiment II, the effect of photoperiod on onset of anestrus was studied in 3 groups of 7 mares each. Mares in group A, as part of a previous experiment, were induced to enter the breeding season earlier than normal by a gradual increase in daily photoperiod beginning on Oct 13, 1972. From Feb 16, 1973, to June 22, 1973, group A mares were maintained at a fixed daily photoperiod of 15 hours 23 minutes. Mares in group B, as part of a previous experiment, were kept under environmental conditions simulating normal conditions in southern Wisconsin. On June 22, 1973 (beginning of the present

  15. 78 FR 27427 - Outer Continental Shelf (OCS) Geological and Geophysical Exploration Activities in the Gulf of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-10

    ... Bureau of Ocean Energy Management Outer Continental Shelf (OCS) Geological and Geophysical Exploration... ] Geological and Geophysical Exploration for Mineral Resources on the Gulf of Mexico Outer Continental Shelf... activities in GOM waters. It will also provide information for future decisions regarding Outer...

  16. 76 FR 58273 - Agency Information Collection Activities; Proposed Collection; Comment Request; Outer Continental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-20

    ... Collection Activities; Proposed Collection; Comment Request; Outer Continental Shelf Air Regulations; EPA ICR... all outer continental shelf (OCS) sources except those located in the Gulf of Mexico west of 87.5... boundary extends three leagues (about nine miles) from the coastline. Title: Outer Continental Shelf...

  17. Activating β-catenin signaling in CD133-positive dermal papilla cells increases hair inductivity.

    PubMed

    Zhou, Linli; Yang, Kun; Xu, Mingang; Andl, Thomas; Millar, Sarah E; Boyce, Steven; Zhang, Yuhang

    2016-08-01

    Bioengineering hair follicles using cells isolated from human tissue remains a difficult task. Dermal papilla (DP) cells are known to guide the growth and cycling activities of hair follicles by interacting with keratinocytes. However, DP cells quickly lose their inductivity during in vitro passaging. Rodent DP cell cultures need external addition of growth factors, including WNT and BMP molecules, to maintain the hair inductive property. CD133 is expressed by a subpopulation of DP cells that are capable of inducing hair follicle formation in vivo. We report here that expression of a stabilized form of β-catenin promoted clonal growth of CD133-positive (CD133+) DP cells in in vitro three-dimensional hydrogel culture while maintaining expression of DP markers, including alkaline phosphatase (AP), CD133, and integrin α8. After a 2-week in vitro culture, cultured CD133+ DP cells with up-regulated β-catenin activity led to an accelerated in vivo hair growth in reconstituted skin compared to control cells. Further analysis showed that matrix cell proliferation and differentiation were significantly promoted in hair follicles when β-catenin signaling was up-regulated in CD133+ DP cells. Our data highlight an important role for β-catenin signaling in promoting the inductive capability of CD133+ DP cells for in vitro expansion and in vivo hair follicle regeneration, which could potentially be applied to cultured human DP cells. PMID:27312243

  18. Legal regime of human activities in outer space law

    NASA Technical Reports Server (NTRS)

    Golda, Carlo

    1994-01-01

    Current developments in space activities increasingly involve the presence of humans on board spacecraft and, in the near future, on the Moon, on Mars, on board Space Stations, etc. With respect to these challenges, the political and legal issues connected to the status of astronauts are largely unclear and require a new doctrinal attention. In the same way, many legal and political questions remain open in the structure of future space crews: the need for international standards in the definition and training of astronauts, etc.; but, first of all, an international uniform legal definition of astronauts. Moreover, the legal structure for human life and operations in outer space can be a new and relevant paradigm for the definition of similar rules in all the situations and environments in which humans are involved in extreme frontiers. The present article starts from an overview on the existing legal and political definitions of 'astronauts', moving to the search of a more useful definition. This is followed by an analysis of the concrete problems created by human space activities, and the legal and political responses to them (the need for a code of conduct; the structure of the crew and the existing rules in the US and ex-USSR; the new legal theories on the argument; the definition and structure of a code of conduct; the next legal problems in fields such as privacy law, communications law, business law, criminal law, etc.).

  19. Tmc1 Point Mutation Affects Ca2+ Sensitivity and Block by Dihydrostreptomycin of the Mechanoelectrical Transducer Current of Mouse Outer Hair Cells

    PubMed Central

    Corns, Laura F.; Johnson, Stuart L.; Kros, Corné J.

    2016-01-01

    The transduction of sound into electrical signals depends on mechanically sensitive ion channels in the stereociliary bundle. The molecular composition of this mechanoelectrical transducer (MET) channel is not yet known. Transmembrane channel-like protein isoforms 1 (TMC1) and 2 (TMC2) have been proposed to form part of the MET channel, although their exact roles are still unclear. Using Beethoven (Tmc1Bth/Bth) mice, which have an M412K point mutation in TMC1 that adds a positive charge, we found that Ca2+ permeability and conductance of the MET channel of outer hair cells (OHCs) were reduced. Tmc1Bth/Bth OHCs were also less sensitive to block by the permeant MET channel blocker dihydrostreptomycin, whether applied extracellularly or intracellularly. These findings suggest that the amino acid that is mutated in Bth is situated at or near the negatively charged binding site for dihydrostreptomycin within the permeation pore of the channel. We also found that the Ca2+ dependence of the operating range of the MET channel was altered by the M412K mutation. Depolarization did not increase the resting open probability of the MET current of Tmc1Bth/Bth OHCs, whereas raising the intracellular concentration of the Ca2+ chelator BAPTA caused smaller increases in resting open probability in Bth mutant OHCs than in wild-type control cells. We propose that these observations can be explained by the reduced Ca2+ permeability of the mutated MET channel indirectly causing the Ca2+ sensor for adaptation, at or near the intracellular face of the MET channel, to become more sensitive to Ca2+ influx as a compensatory mechanism. SIGNIFICANCE STATEMENT In the auditory system, the hair cells convert sound-induced mechanical movement of the hair bundles atop these cells into electrical signals through the opening of mechanically gated ion channels at the tips of the bundles. Although the nature of these mechanoelectrical transducer (MET) channels is still unclear, recent studies implicate

  20. Spontaneous oscillations, signal amplification and synchronization in a model of active hair bundle mechanics

    PubMed Central

    Han, Lijuan; Neiman, Alexander B.

    2010-01-01

    We study spontaneous dynamics and signal transduction in a model of active hair bundle mechanics of sensory hair cells. The hair bundle motion is subjected to internal noise resulted from thermal fluctuations and stochastic dynamics of mechano-electrical transduction ion channels. Similar to other studies we found that in the presence of noise the coherence of stochastic oscillations is maximal at a point on the bifurcation diagram away from the Andronov-Hopf bifurcation and is close to the point of maximum sensitivity of the system to weak periodic mechanical perturbations. Despite decoherent effect of noise the stochastic hair bundle oscillations can be synchronized by external periodic force of few pN amplitude in a finite range of control parameters. We then study effects of receptor potential oscillations on mechanics of the hair bundle and show that the hair bundle oscillations can be synchronized by oscillating receptor voltage. Moreover, using a linear model for the receptor potential we show that bi-directional coupling of the hair bundle and the receptor potential results in significant enhancement of the coherence of spontaneous oscillations and of the sensitivity to the external mechanical perturbations. PMID:20481759

  1. Chloride-driven Electromechanical Phase Lags at Acoustic Frequencies Are Generated by SLC26a5, the Outer Hair Cell Motor Protein

    PubMed Central

    Santos-Sacchi, Joseph; Song, Lei

    2014-01-01

    Outer hair cells (OHC) possess voltage-dependent membrane bound molecular motors, identified as the solute carrier protein SLC26a5, that drive somatic motility at acoustic frequencies. The electromotility (eM) of OHCs provides for cochlear amplification, a process that enhances auditory sensitivity by up to three orders of magnitude. In this study, using whole cell voltage clamp and mechanical measurement techniques, we identify disparities between voltage sensing and eM that result from stretched exponential electromechanical behavior of SLC26a5, also known as prestin, for its fast responsiveness. This stretched exponential behavior, which we accurately recapitulate with a new kinetic model, the meno presto model of prestin, influences the protein’s responsiveness to chloride binding and provides for delays in eM relative to membrane voltage driving force. The model predicts that in the frequency domain, these delays would result in eM phase lags that we confirm by measuring OHC eM at acoustic frequencies. These lags may contribute to canceling viscous drag, a requirement for many models of cochlear amplification. PMID:24988347

  2. Hair growth activity of Crataegus pinnatifida on C57BL/6 mouse model.

    PubMed

    Shin, Heon-Sub; Lee, Jung-Min; Park, Sang-Yong; Yang, Jung-Eun; Kim, Ju-Han; Yi, Tae-Hoo

    2013-09-01

    Crataegus pinnatifida has a long history of use in traditional oriental herbal medicine to stimulating digestion and improving blood circulation. Based on nutrition of hair, the present study was conducted to assess the effect of C. pinnatifida extract on hair growth using mouse model and its mechanisms of action. The C. pinnatifida extract containing the contents of total polyphenol of 5.88□0.82 g gallic acid/100 g extract and proanthocyanidin of 9.15□1.58 mg cyaniding chloride/100 g extract was orally administered daily at a dosage of 50 mg/kg weight to the 7-week-old C57BL/6 mice in telogen. The C. pinnatifida extract promoted hair growth by inducing anagen phase in mice in telogen, reflected by color of skin, thickness of hair shaft, and density of hair. The ratio of anagento telogen was determined by shape of hair follicles in vertically sectioned slide and increased by oral administration of C. pinnatifida extract. The number and the size of hair follicles were also enlarged, indicating anagen phase induction. The proliferation of human dermal papilla cells (hDPC) was accelerated by addition of C. pinnatifida extract, which activated the signaling of mitogen-activated protein kinases (Erk, p-38, and JNK) and Akt. Moreover, the ratio of Bcl-2/Bax as the determinant of cell fate was also raised in skin. These results suggest that the C. pinnatifida extract promotes hair growth by inducing anagen phase, which might be mediated by the activation of cellular signalings that enhance the survival of cultured hDPC and the increase of the ratio of Bcl-2 to Bax that protects cells against cell death. PMID:23148028

  3. Mutation of the TBCE gene causes disturbance of microtubules in the auditory nerve and cochlear outer hair cell degeneration accompanied by progressive hearing loss in the pmn/pmn mouse.

    PubMed

    Rak, Kristen; Frenz, Silke; Radeloff, Andreas; Groh, Janos; Jablonka, Sibylle; Martini, Rudolf; Hagen, Rudolf; Mlynski, Robert

    2013-12-01

    The progressive motor neuronopathy (pmn/pmn) mouse, an animal model for a fast developing human motor neuron disorder, is additionally characterized by simultaneous progressive sensorineural hearing loss. The gene defect in the pmn/pmn mouse is localized to a missense mutation in the tubulin-specific chaperone E (TBCE) gene on mouse chromosome 13, which is one of the five tubulin-specific chaperons involved in tubulin folding and dimerization. The missense mutation leads to a disturbance of tubulin structures in the auditory nerve and a progressive outer hair cell loss due to apoptosis, which is accompanied by highly elevated ABR-thresholds and loss of DPOAEs. In addition the TBCE protein is selectively expressed in the outer hair cells and the transcellular processes of the inner pillar cells in the cochlea of control and pmn/pmn mouse. We conclude from our study that the mutation of the TBCE gene affects the auditory nerve and the cochlear hair cells simultaneously, leading to progressive hearing loss. This animal model will give the chance to test possible therapeutic strategies in special forms of hearing loss, in which the auditory nerve and the cochlear hair cells are simultaneously affected. PMID:24120439

  4. Therapeutic strategy for hair regeneration: Hair cycle activation, niche environment modulation, wound-induced follicle neogenesis and stem cell engineering

    PubMed Central

    Chueh, Shan-Chang; Lin, Sung-Jan; Chen, Chih-Chiang; Lei, Mingxing; Wang, Ling Mei; Widelitz, Randall B.; Hughes, Michael W.; Jiang, Ting-Xing; Chuong, Cheng Ming

    2013-01-01

    Introduction There are major new advancements in the fields of stem cell biology, developmental biology, regenerative hair cycling, and tissue engineering. The time is ripe to integrate, translate and apply these findings to tissue engineering and regenerative medicine. Readers will learn about new progress in cellular and molecular aspects of hair follicle development, regeneration and potential therapeutic opportunities these advances may offer. Areas covered Here we use hair follicle formation to illustrate this progress and to identify targets for potential strategies in therapeutics. Hair regeneration is discussed in four different categories. (1) Intra-follicle regeneration (or renewal) is the basic production of hair fibers from hair stem cells and dermal papillae in existing follicles. (2) Chimeric follicles via epithelial-mesenchymal recombination to identify stem cells and signaling centers. (3) Extra-follicular factors including local dermal and systemic factors can modulate the regenerative behavior of hair follicles, and may be relatively easy therapeutic targets. (4) Follicular neogenesis means the de novo formation of new follicles. In addition, scientists are working to engineer hair follicles, which require hair forming competent epidermal cells and hair inducing dermal cells. Expert opinion Ideally self-organizing processes similar to those occurring during embryonic development should be elicited with some help from biomaterials. PMID:23289545

  5. Macrophages contribute to the cyclic activation of adult hair follicle stem cells.

    PubMed

    Castellana, Donatello; Paus, Ralf; Perez-Moreno, Mirna

    2014-12-01

    Skin epithelial stem cells operate within a complex signaling milieu that orchestrates their lifetime regenerative properties. The question of whether and how immune cells impact on these stem cells within their niche is not well understood. Here we show that skin-resident macrophages decrease in number because of apoptosis before the onset of epithelial hair follicle stem cell activation during the murine hair cycle. This process is linked to distinct gene expression, including Wnt transcription. Interestingly, by mimicking this event through the selective induction of macrophage apoptosis in early telogen, we identify a novel involvement of macrophages in stem cell activation in vivo. Importantly, the macrophage-specific pharmacological inhibition of Wnt production delays hair follicle growth. Thus, perifollicular macrophages contribute to the activation of skin epithelial stem cells as a novel, additional cue that regulates their regenerative activity. This finding may have translational implications for skin repair, inflammatory skin diseases and cancer. PMID:25536657

  6. Macrophages Contribute to the Cyclic Activation of Adult Hair Follicle Stem Cells

    PubMed Central

    Castellana, Donatello; Paus, Ralf; Perez-Moreno, Mirna

    2014-01-01

    Skin epithelial stem cells operate within a complex signaling milieu that orchestrates their lifetime regenerative properties. The question of whether and how immune cells impact on these stem cells within their niche is not well understood. Here we show that skin-resident macrophages decrease in number because of apoptosis before the onset of epithelial hair follicle stem cell activation during the murine hair cycle. This process is linked to distinct gene expression, including Wnt transcription. Interestingly, by mimicking this event through the selective induction of macrophage apoptosis in early telogen, we identify a novel involvement of macrophages in stem cell activation in vivo. Importantly, the macrophage-specific pharmacological inhibition of Wnt production delays hair follicle growth. Thus, perifollicular macrophages contribute to the activation of skin epithelial stem cells as a novel, additional cue that regulates their regenerative activity. This finding may have translational implications for skin repair, inflammatory skin diseases and cancer. PMID:25536657

  7. Activation and adaptation of transducer currents in turtle hair cells.

    PubMed

    Crawford, A C; Evans, M G; Fettiplace, R

    1989-12-01

    1. Transducer currents were recorded in turtle cochlear hair cells during mechanical stimulation of the hair bundle. The currents were measured under whole-cell voltage clamp in isolated cells that were firmly stuck to the floor of the recording chamber. 2. Stimuli were calibrated by projecting the image of the hair bundle onto a rapidly scanned 128 photodiode array. This technique showed that, while the cell body was immobilized, the tip of the bundle would follow faithfully the motion of an attached glass probe up to frequencies of more than 1 kHz. 3. The relationship between inward transducer current and bundle displacement was sigmoidal. Maximum currents of 200-400 pA were observed for deflections of the tip of the bundle of 0.5 microns, equivalent to rotating the bundle by about 5 deg. 4. In response to a step deflection of the bundle, the current developed with a time constant (about 0.4 ms for small stimuli) that decreased with the size of displacement. This suggests that the onset of the current was limited by the gating kinetics of the transduction channel. The onset time course was slowed about fourfold for a 20 degrees C drop in temperature. 5. For small maintained displacements, the current relaxed to about a quarter of the peak level with a time constant of 3-5 ms. This adaptation was associated with a shift of the current-displacement relationship in the direction of the stimulus. The rate and extent of adaptation were decreased by lowering external Ca2+. 6. Adaptation was strongly voltage sensitive, and was abolished at holding potentials positive to the reversal potential of the transducer current of about 0 mV. It was also diminished by loading cells with 10 mM of the Ca2+ chelator BAPTA. These observations suggest that adaptation may be partly controlled by influx of Ca2+ through the transducer channels. 7. Removal of adaptation produced asymmetric responses, with fast onsets but slow decays following return of the bundle to its resting position

  8. Hoxc13 is a crucial regulator of murine hair cycle.

    PubMed

    Qiu, Weiming; Lei, Mingxing; Tang, Hui; Yan, Hongtao; Wen, Xuhong; Zhang, Wei; Tan, Ranjing; Wang, Duan; Wu, Jinjin

    2016-04-01

    Hair follicles undergo cyclical growth and regression during postnatal life. Hair regression is an apoptosis-driven process strictly controlled by micro- and macro-environmental signals. However, how these signals are controlled remains largely unknown. Hoxc13, a member of the Hox gene family, is reported to play an important role in hair follicle differentiation. In the present study, we observed that Hoxc13 was highly expressed in the outer root sheath, matrix, medulla and inner root sheath of hair follicles in a hair cycle-dependent manner. We therefore investigated the role of Hoxc13 in hair follicle cycling. Injection of ShRNA (ShHoxc13) to suppress Hoxc13 in early anagen promoted premature catagen entry, shown by significantly decreased hair length and hair bulb size, increased percentage of catagen hair follicles, hair cycle score and TUNEL+ cells and inhibited proliferation. In contrast, local injection of recombinant Hoxc13 polypeptide (rhHoxc13) during the late anagen phase prolonged the anagen phase. Additionally, rhHoxc13 injections during the telogen phase significantly promoted hair growth and induced the anagen progression. At the molecular level, the expression of phosphorylated smad2 (p-smad2), a key factor of active TGF-β1 signaling, was up-regulated in the ShHoxc13-treated hair follicles and down-regulated in rhHoxc13-treated hair follicles, suggesting that Hoxc13 might block anagen-catagen transition by inhibiting the TGF-β1 signaling. Taken together, our data strongly suggest that Hoxc13 is a novel and crucial regulator of the hair cycle. This might also provide an understanding of the mechanism of the 'hair cycle clock' and the development of alopecia treatments. PMID:26553656

  9. Minireview: Hair Cortisol: A Novel Biomarker of Hypothalamic-Pituitary-Adrenocortical Activity

    PubMed Central

    Novak, Melinda A.

    2012-01-01

    Activity of the hypothalamic-pituitary-adrenocortical (HPA) axis is commonly assessed by measuring glucocorticoids such as cortisol (CORT). For many years, CORT was obtained primarily from blood plasma or urine, whereas later approaches added saliva and feces for noninvasive monitoring of HPA functioning. Despite the value of all these sample matrices for answering many research questions, they remain limited in the temporal range of assessment. Plasma and saliva are point samples that vary as a function of circadian rhythmicity and are susceptible to confounding by environmental disturbances. Even urine and feces generally assess HPA activity over a period of only 24 h or less. We and others have recently developed and validated methods for measuring the concentration of CORT in the body hair of animals (e.g. rhesus monkeys) and scalp hair of humans. CORT is constantly deposited in the growing hair shaft, as a consequence of which such deposition can serve as a biomarker of integrated HPA activity over weeks and months instead of minutes or hours. Since the advent of this methodological advance, hair CORT has already been used as an index of chronic HPA activity and stress in human clinical and nonclinical populations, in a variety of laboratory-housed and wild-living animal species, and in archival specimens that are many decades or even centuries old. Moreover, because human hair is known to grow at an average rate of about 1 cm/month, several studies suggest that CORT levels in hair segments that differ in proximity to the scalp can, under certain conditions, be used as a retrospective calendar of HPA activity during specific time periods preceding sample collection. PMID:22778226

  10. 78 FR 33859 - Outer Continental Shelf (OCS) Geological and Geophysical Exploration Activities in the Gulf of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ... Bureau of Ocean Energy Management Outer Continental Shelf (OCS) Geological and Geophysical Exploration.... SUMMARY: On May 10, 2013, BOEM published a document in the Federal Register (78 FR 27427) entitled ``Outer Continental Shelf Geological and Geophysical Exploration Activities in the Gulf of Mexico.'' This...

  11. Estrogenic and anti-estrogenic activity of off-the-shelf hair and skin care products.

    PubMed

    Myers, Sharon L; Yang, Chun Z; Bittner, George D; Witt, Kristine L; Tice, Raymond R; Baird, Donna D

    2015-05-01

    Use of personal care products is widespread in the United States but tends to be greater among African Americans than whites. Of special concern is the possible hazard of absorption of chemicals with estrogenic activity (EA) or anti-EA (AEA) in these products. Such exposure may have adverse health effects, especially when it occurs during developmental windows (e.g., prepubertally) when estrogen levels are low. We assessed the ethanol extracts of eight commonly used hair and skin products popular among African Americans for EA and AEA using a cell proliferation assay with the estrogen sensitive MCF-7:WS8 cell line derived from a human breast cancer. Four of the eight personal care products tested (Oil Hair Lotion, Extra-dry Skin Lotion, Intensive Skin Lotion, Petroleum Jelly) demonstrated detectable EA, whereas three (Placenta Hair Conditioner, Tea-Tree Hair Conditioner, Cocoa Butter Skin Cream) exhibited AEA. Our data indicate that hair and skin care products can have EA or AEA, and suggest that laboratory studies are warranted to investigate the in vivo activity of such products under chronic exposure conditions as well as epidemiologic studies to investigate potential adverse health effects that might be associated with use of such products. PMID:24849798

  12. Estrogenic and anti-estrogenic activity of off-the-shelf hair and skin care products

    PubMed Central

    Myers, Sharon L.; Yang, Chun Z.; Bittner, George D.; Witt, Kristine L.; Tice, Raymond R.; Baird, Donna D.

    2014-01-01

    Use of personal care products is widespread in the United States but tends to be greater among African Americans than whites. Of special concern is the possible hazard of absorption of chemicals with estrogenic activity (EA) or anti-EA (AEA) in these products. Such exposure may have adverse health effects, especially when it occurs during developmental windows (e.g., prepubertally) when estrogen levels are low. We assessed the ethanol extracts of eight commonly used hair and skin products popular among African Americans for EA and AEA using a cell proliferation assay with the estrogen sensitive MCF-7:WS8 cell line derived from a human breast cancer. Four of the eight personal care products tested (Oil Hair Lotion, Extra-dry Skin Lotion, Intensive Skin Lotion, Petroleum Jelly) demonstrated detectable EA, whereas three (Placenta Hair Conditioner, Tea-Tree Hair Conditioner, Cocoa Butter Skin Cream) exhibited AEA. Our data indicate that hair and skin care products can have EA or AEA, and suggest that laboratory studies are warranted to investigate the in vivo activity of such products under chronic exposure conditions as well as epidemiologic studies to investigate potential adverse health effects that might be associated with use of such products. PMID:24849798

  13. Fast Adaptation in Vestibular Hair Cells Requires Myosin-1c Activity

    PubMed Central

    Stauffer, Eric A.; Scarborough, John D.; Hirono, Moritoshi; Miller, Emilie D.; Shah, Kavita; Mercer, John A.; Holt, Jeffrey R.; Gillespie, Peter G.

    2009-01-01

    Summary In sensory hair cells of the inner ear, mechanical amplification of small stimuli requires fast adaptation, the rapid closing of mechanically activated transduction channels. In frog and mouse vestibular hair cells, we found that the rate of fast adaptation depends on both channel opening and stimulus size and that it is modeled well as a release of a mechanical element in series with the transduction apparatus. To determine whether myosin-1c molecules of the adaptation motor are responsible for the release, we introduced the Y61G mutation into the Myo1c locus and generated mice homozygous for this sensitized allele. Measuring transduction and adaptation in the presence of NMB-ADP, an allele-specific inhibitor, we found that the inhibitor not only blocked slow adaptation, as demonstrated previously in transgenic mice, but also inhibited fast adaptation. These results suggest that mechanical activity of myosin-1c is required for fast adaptation in vestibular hair cells. PMID:16102537

  14. Hair Cortisol Analysis: A Promising Biomarker of HPA Activation in Older Adults

    PubMed Central

    Wright, Kathy D.; Hickman, Ronald; Laudenslager, Mark L.

    2015-01-01

    Prolonged stress is a potentially harmful and often undetected risk factor for chronic illness in older adults. Cortisol, one indicator of the body’s hormonal responses to stress, is regulated by the hypothalamic-pituitary-adrenal (HPA) axis and is commonly measured in saliva, urine, or blood samples. Cortisol possesses a diurnal pattern and thus collection timing is critical. Hair cortisol is a proxy measure to the total retrospective activity of the HPA axis over the preceding months, much like hemoglobin A1c is a proxy measure of glucose control over the past 3 months. The aim of this review is to examine a novel biomarker, hair cortisol, as a practical measure of long-term retrospective cortisol activity associated with chronic stress in older adults. Hair cortisol analysis advances the science of aging by better characterizing chronic stress as a risk factor for chronic illness progression and as a biomarker of the effectiveness of stress reduction interventions. PMID:26055775

  15. Somatic motility and hair bundle mechanics, are both necessary for cochlear amplification?

    PubMed Central

    Peng, Anthony W.; Ricci, Anthony J.

    2010-01-01

    Hearing organs have evolved to detect sounds across several orders of magnitude of both intensity and frequency. Detection limits are at the atomic level despite the energy associated with sound being limited thermodynamically. Several mechanisms have evolved to account for the remarkable frequency selectivity, dynamic range, and sensitivity of these various hearing organs, together termed the active process or cochlear amplifier. Similarities between hearing organs of disparate species provides insight into the factors driving the development of the cochlear amplifier. These properties include: a tonotopic map, the emergence of a two hair cell system, the separation of efferent and afferent innervations, the role of the tectorial membrane, and the shift from intrinsic tuning and amplification to a more end organ driven process. Two major contributors to the active process are hair bundle mechanics and outer hair cell electromotility, the former present in all hair cell organs tested, the latter only present in mammalian cochlear outer hair cells. Both of these processes have advantages and disadvantages, and how these processes interact to generate the active process in the mammalian system is highly disputed. A hypothesis is put forth suggesting that hair bundle mechanics provides amplification and filtering in most hair cells, while in mammalian cochlea, outer hair cell motility provides the amplification on a cycle by cycle basis driven by the hair bundle that provides frequency selectivity (in concert with the tectorial membrane) and compressive nonlinearity. Separating components of the active process may provide additional sites for regulation of this process. PMID:20430075

  16. Activation of PI3K signaling prevents aminoglycoside-induced hair cell death in the murine cochlea

    PubMed Central

    Jadali, Azadeh

    2016-01-01

    ABSTRACT Loss of sensory hair cells of the inner ear due to aminoglycoside exposure is a major cause of hearing loss. Using an immortalized multipotent otic progenitor (iMOP) cell line, specific signaling pathways that promote otic cell survival were identified. Of the signaling pathways identified, the PI3K pathway emerged as a strong candidate for promoting hair cell survival. In aging animals, components for active PI3K signaling are present but decrease in hair cells. In this study, we determined whether activated PI3K signaling in hair cells promotes survival. To activate PI3K signaling in hair cells, we used a small molecule inhibitor of PTEN or genetically ablated PTEN using a conditional knockout animal. Hair cell survival was challenged by addition of gentamicin to cochlear cultures. Hair cells with activated PI3K signaling were more resistant to aminoglycoside-induced hair cell death. These results indicate that increased PI3K signaling in hair cells promote survival and the PI3K signaling pathway is a target for preventing aminoglycoside-induced hearing loss. PMID:27142333

  17. Activation of PI3K signaling prevents aminoglycoside-induced hair cell death in the murine cochlea.

    PubMed

    Jadali, Azadeh; Kwan, Kelvin Y

    2016-01-01

    Loss of sensory hair cells of the inner ear due to aminoglycoside exposure is a major cause of hearing loss. Using an immortalized multipotent otic progenitor (iMOP) cell line, specific signaling pathways that promote otic cell survival were identified. Of the signaling pathways identified, the PI3K pathway emerged as a strong candidate for promoting hair cell survival. In aging animals, components for active PI3K signaling are present but decrease in hair cells. In this study, we determined whether activated PI3K signaling in hair cells promotes survival. To activate PI3K signaling in hair cells, we used a small molecule inhibitor of PTEN or genetically ablated PTEN using a conditional knockout animal. Hair cell survival was challenged by addition of gentamicin to cochlear cultures. Hair cells with activated PI3K signaling were more resistant to aminoglycoside-induced hair cell death. These results indicate that increased PI3K signaling in hair cells promote survival and the PI3K signaling pathway is a target for preventing aminoglycoside-induced hearing loss. PMID:27142333

  18. Forensic Science: Hair Identification.

    ERIC Educational Resources Information Center

    Keller, Elhannan L.

    1980-01-01

    Presented is an activity in which students use a microscope to do a forensic hair comparative study and a medullary classification. Mounting methods, medulla types, hair photographs, and activities are described. (DS)

  19. Hair transplant

    MedlinePlus

    ... this procedure: Scarring Unnatural-looking tufts of new hair growth It is possible that the transplanted hair will ... Most hair transplants result in excellent hair growth within several ... may be needed to create best results. The replaced hairs are ...

  20. Body Hair

    MedlinePlus

    ... girlshealth.gov/ Home Body Puberty Body hair Body hair Even before you get your first period , you ... removing pubic hair Ways to get rid of hair top Removing body hair can cause skin irritation, ...

  1. 75 FR 70021 - Environmental Documents Prepared in Support of Oil and Gas Activities on the Alaska Outer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-16

    ... of Oil and Gas Activities on the Alaska Outer Continental Shelf AGENCY: Bureau of Ocean Energy... (FONSI) prepared for two oil and gas activities proposed on the Alaska Outer Continental Shelf (OCS)...

  2. Activation of β-Catenin Signaling in CD133-Positive Dermal Papilla Cells Drives Postnatal Hair Growth.

    PubMed

    Zhou, Linli; Xu, Mingang; Yang, Yongguang; Yang, Kun; Wickett, Randall R; Andl, Thomas; Millar, Sarah E; Zhang, Yuhang

    2016-01-01

    The hair follicle dermal papilla (DP) contains a unique prominin-1/CD133-positive (CD133+) cell subpopulation, which has been shown to possess hair follicle-inducing capability. By assaying for endogenous CD133 expression and performing lineage tracing using CD133-CreERT2; ZsGreen1 reporter mice, we find that CD133 is expressed in a subpopulation of DP cells during the growth phase of the murine hair cycle (anagen), but is absent at anagen onset. However, how CD133+ DP cells interact with keratinocytes to induce hair regenerative growth remains unclear. Wnt/β-catenin has long been recognized as a major signaling pathway required for hair follicle morphogenesis, development, and regeneration. Nuclear Wnt/β-catenin activity is observed in the DP during the hair growth phase. Here we show that induced expression of a stabilized form of β-catenin in CD133+ DP cells significantly accelerates spontaneous and depilation-induced hair growth. However, hair follicle regression is not affected in these mutants. Further analysis indicates that CD133+ DP-expressed β-catenin increases proliferation and differentiation of epithelial matrix keratinocytes. Upregulated Wnt/β-catenin activity in CD133+ DP cells also increases the number of proliferating DP cells in each anagen follicle. Our data demonstrate that β-catenin signaling potentiates the capability of CD133+ DP cells to promote postnatal hair growth. PMID:27472062

  3. Activation of β-Catenin Signaling in CD133-Positive Dermal Papilla Cells Drives Postnatal Hair Growth

    PubMed Central

    Zhou, Linli; Xu, Mingang; Yang, Yongguang; Yang, Kun; Wickett, Randall R.; Andl, Thomas; Millar, Sarah E.

    2016-01-01

    The hair follicle dermal papilla (DP) contains a unique prominin-1/CD133-positive (CD133+) cell subpopulation, which has been shown to possess hair follicle-inducing capability. By assaying for endogenous CD133 expression and performing lineage tracing using CD133-CreERT2; ZsGreen1 reporter mice, we find that CD133 is expressed in a subpopulation of DP cells during the growth phase of the murine hair cycle (anagen), but is absent at anagen onset. However, how CD133+ DP cells interact with keratinocytes to induce hair regenerative growth remains unclear. Wnt/β-catenin has long been recognized as a major signaling pathway required for hair follicle morphogenesis, development, and regeneration. Nuclear Wnt/β-catenin activity is observed in the DP during the hair growth phase. Here we show that induced expression of a stabilized form of β-catenin in CD133+ DP cells significantly accelerates spontaneous and depilation-induced hair growth. However, hair follicle regression is not affected in these mutants. Further analysis indicates that CD133+ DP-expressed β-catenin increases proliferation and differentiation of epithelial matrix keratinocytes. Upregulated Wnt/β-catenin activity in CD133+ DP cells also increases the number of proliferating DP cells in each anagen follicle. Our data demonstrate that β-catenin signaling potentiates the capability of CD133+ DP cells to promote postnatal hair growth. PMID:27472062

  4. Aging of hair.

    PubMed

    Trüeb, Ralph M

    2005-06-01

    The appearance of hair plays an important role in people's overall physical appearance and self-perception. With today's increasing life expectation, the desire to look youthful plays a bigger role than ever. The hair care industry has become aware of this and also more capable to deliver active products that are directed toward meeting this consumer demand. The discovery of pharmacological targets and the development of safe and effective drugs also indicate strategies of the drug industry for maintenance of healthy and beautiful hair. Hair aging comprises weathering of the hair shaft and aging of the hair follicle. The latter manifests as decrease of melanocyte function or graying, and decrease in hair production in androgenetic and senescent alopecia. The scalp is also subject to intrinsic or physiologic aging and extrinsic aging caused by external factors. Intrinsic factors are related to individual genetic and epigenetic mechanisms with interindividual variation. Prototypes are familial premature graying and androgenetic alopecia. Extrinsic factors include ultraviolet radiation and smoking. Experimental evidence supports the hypothesis that oxidative stress plays a role in skin and hair aging. Topical anti-aging compounds for hair include humefactants, hair conditioners, photoprotectors, and antioxidants. Current available treatment modalities with proven efficacy for treatment of androgenetic alopecia are topical minoxidil, oral finasteride, and autologous hair transplantation. In the absence of another way to reverse hair graying, hair colorants are the mainstays of recovering lost hair color. Topical liposome targeting for melanins, genes, and proteins selectively to hair follicles are under current investigation. PMID:17166201

  5. Spontaneous Activity of Cochlear Hair Cells Triggered by Fluid Secretion Mechanism in Adjacent Support Cells.

    PubMed

    Wang, Han Chin; Lin, Chun-Chieh; Cheung, Rocky; Zhang-Hooks, YingXin; Agarwal, Amit; Ellis-Davies, Graham; Rock, Jason; Bergles, Dwight E

    2015-12-01

    Spontaneous electrical activity of neurons in developing sensory systems promotes their maturation and proper connectivity. In the auditory system, spontaneous activity of cochlear inner hair cells (IHCs) is initiated by the release of ATP from glia-like inner supporting cells (ISCs), facilitating maturation of central pathways before hearing onset. Here, we find that ATP stimulates purinergic autoreceptors in ISCs, triggering Cl(-) efflux and osmotic cell shrinkage by opening TMEM16A Ca(2+)-activated Cl(-) channels. Release of Cl(-) from ISCs also forces K(+) efflux, causing transient depolarization of IHCs near ATP release sites. Genetic deletion of TMEM16A markedly reduces the spontaneous activity of IHCs and spiral ganglion neurons in the developing cochlea and prevents ATP-dependent shrinkage of supporting cells. These results indicate that supporting cells in the developing cochlea have adapted a pathway used for fluid secretion in other organs to induce periodic excitation of hair cells. PMID:26627734

  6. Active magnetic bearings used as exciters for rolling element bearing outer race defect diagnosis.

    PubMed

    Xu, Yuanping; Di, Long; Zhou, Jin; Jin, Chaowu; Guo, Qintao

    2016-03-01

    The active health monitoring of rotordynamic systems in the presence of bearing outer race defect is considered in this paper. The shaft is assumed to be supported by conventional mechanical bearings and an active magnetic bearing (AMB) is used in the mid of the shaft location as an exciter to apply electromagnetic force to the system. We investigate a nonlinear bearing-pedestal system model with the outer race defect under the electromagnetic force. The nonlinear differential equations are integrated using the fourth-order Runge-Kutta algorithm. The simulation and experimental results show that the characteristic signal of outer race incipient defect is significantly amplified under the electromagnetic force through the AMBs, which is helpful to improve the diagnosis accuracy of rolling element bearing׳s incipient outer race defect. PMID:26803551

  7. Activities conducted during the definition phase of the outer planets missions program

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The activities are described of the Meteoroid Science Team for the definition phase of the outer planet missions. Studies reported include: (1) combined zodiacal experiment for the Grand Tour Missions of the outer planets, (2) optical transmission of a honeycomb panel and its effectiveness as a particle impact surface, (3) element identification data from the combined zodiacal OPGT experiment and (4) development of lightweight thermally stable mirrors.

  8. Root Hair Deformation Activity of Nodulation Factors and Their Fate on Vicia sativa.

    PubMed Central

    Heidstra, R.; Geurts, R.; Franssen, H.; Spaink, H. P.; Van Kammen, A.; Bisseling, T.

    1994-01-01

    We used a semiquantitative root hair deformation assay for Vicia sativa (vetch) to study the activity of Rhizobium leguminosarum bv viciae nodulation (Nod) factors. Five to 10 min of Nod factor-root interaction appears to be sufficient to induce root hair deformation. The first deformation is visible within 1 h, and after 3 h about 80% of the root hairs in a small susceptible zone of the root are deformed. This zone encompasses root hairs that have almost reached their maximal size. The Nod factor accumulates preferentially to epidermal cells of the young part of the root, but is not restricted to the susceptible zone. In the interaction with roots, the glucosamine backbone of Nod factors is shortened, presumably by chitinases. NodRlv-IV(C18:4,Ac) is more stable than NodRlv-V(C18:4,Ac). No correlation was found between Nod factor degradation and susceptibility. Degradation occurs both in the susceptible zone and in the mature zone. Moreover, degradation is not affected by NH4NO3 and is similar in vetch and in the nonhost alfalfa (Medicago sativa). PMID:12232242

  9. Activation of the OVOL1-OVOL2 Axis in the Hair Bulb and in Pilomatricoma.

    PubMed

    Ito, Takamichi; Tsuji, Gaku; Ohno, Fumitaka; Uchi, Hiroshi; Nakahara, Takeshi; Hashimoto-Hachiya, Akiko; Yoshida, Yuichi; Yamamoto, Osamu; Oda, Yoshinao; Furue, Masutaka

    2016-04-01

    OVOL1 and OVOL2, ubiquitously conserved genes encoding C2H2 zinc finger transcription factors in mammals, control epithelial cell proliferation, and differentiation, including those in skin. OVOL1 and OVOL2 expression is coordinately mediated via the Wnt signaling pathway, and OVOL1 negatively regulates OVOL2 expression in a transcriptional manner. Our previous study of OVOL1 expression in human skin revealed that OVOL1 is preferentially expressed in the inner root sheath of the hair follicle. Therefore, we hypothesized that the OVOL1-OVOL2 axis is involved in normal and neoplastic follicular differentiation. Immunohistochemical analysis showed that OVOL1 and OVOL2 were strongly expressed in a mutually exclusive manner in the cytoplasm of inner root sheath cells and matrix cells, respectively, in normal follicles. OVOL2 was also expressed in pilomatricoma, with only partial expression of OVOL1. Cultured human keratinocytes expressed OVOL1 and OVOL2 on both the mRNA and protein levels. The expression of OVOL2 was higher in keratinocytes transfected with siRNA of OVOL1. Ketoconazole, a hair growth stimulant, up-regulated the expression of OVOL1 but did not affect OVOL2 expression. These results indicated that the OVOL1-OVOL2 axis may actively contribute to cell differentiation and proliferation in the hair bulb, suggesting that the OVOL1 and OVOL2 may be therapeutic targets of hair disorders, including alopecia, and play important roles in the tumorigenesis of pilomatricoma. PMID:26873447

  10. Decoction and Fermentation of Selected Medicinal Herbs Promote Hair Regrowth by Inducing Hair Follicle Growth in Conjunction with Wnts Signaling.

    PubMed

    Jang, Su Kil; Kim, Seung Tae; Lee, Do Ik; Park, Jun Sub; Jo, Bo Ram; Park, Jung Youl; Heo, Jong; Joo, Seong Soo

    2016-01-01

    It is well recognized that regulating the hair follicle cycle in association with Wnt signaling is one of the most interesting targets for promoting hair regrowth. In this study, we examined whether selected herbal medicines processed by decoction and fermentation promote hair growth by upregulating the number and size of hair follicles and Wnt signaling, including activation of β-catenin and Akt in telogen-synchronized C57BL/6N mice. The results revealed that the fermented extract after decoction (FDE) more effectively promoted hair growth than that of a nonfermented extract (DE). Notably, FDE effectively enhanced formation of hair follicles with clearer differentiation between the inner and outer root sheath, which is observed during the anagen phase. Mechanistic evidence was found for increased β-catenin and Akt phosphorylation levels in dorsal skin tissue along with elevated expression of hair regrowth-related genes, such as Wnt3/10a/10b, Lef1, and fibroblast growth factor 7. In conclusion, our findings suggest that FDE plays an important role in regulating the hair cycle by increasing expression of hair regrowth-related genes and activating downstream Wnt signaling targets. PMID:27110266

  11. Decoction and Fermentation of Selected Medicinal Herbs Promote Hair Regrowth by Inducing Hair Follicle Growth in Conjunction with Wnts Signaling

    PubMed Central

    Jang, Su Kil; Kim, Seung Tae; Lee, Do Ik; Park, Jun Sub; Jo, Bo Ram; Park, Jung Youl; Heo, Jong; Joo, Seong Soo

    2016-01-01

    It is well recognized that regulating the hair follicle cycle in association with Wnt signaling is one of the most interesting targets for promoting hair regrowth. In this study, we examined whether selected herbal medicines processed by decoction and fermentation promote hair growth by upregulating the number and size of hair follicles and Wnt signaling, including activation of β-catenin and Akt in telogen-synchronized C57BL/6N mice. The results revealed that the fermented extract after decoction (FDE) more effectively promoted hair growth than that of a nonfermented extract (DE). Notably, FDE effectively enhanced formation of hair follicles with clearer differentiation between the inner and outer root sheath, which is observed during the anagen phase. Mechanistic evidence was found for increased β-catenin and Akt phosphorylation levels in dorsal skin tissue along with elevated expression of hair regrowth-related genes, such as Wnt3/10a/10b, Lef1, and fibroblast growth factor 7. In conclusion, our findings suggest that FDE plays an important role in regulating the hair cycle by increasing expression of hair regrowth-related genes and activating downstream Wnt signaling targets. PMID:27110266

  12. Young Scientists Explore Inner & Outer Space. Book 6--Intermediate Level. A Good Apple Activity Book.

    ERIC Educational Resources Information Center

    DeBruin, Jerry

    Designed to develop creativity in young learners, this book contains interdisciplinary activities which focus on the theme of space (inner and outer). Activity pages are provided that can serve as front and back covers of a student booklet and the suggested activities can be duplicated for insertion between the covers resulting in a booklet for…

  13. Use of hair cortisol analysis to detect hypercortisolism during active drinking phases in alcohol-dependent individuals.

    PubMed

    Stalder, Tobias; Kirschbaum, Clemens; Heinze, Kareen; Steudte, Susann; Foley, Paul; Tietze, Antje; Dettenborn, Lucia

    2010-12-01

    The assessment of cortisol levels in human hair has recently been suggested to provide a retrospective index of cumulative cortisol exposure over periods of up to 6 months. The current study examined the utility of hair cortisol analysis to retrospectively detect hypercortisolism during active drinking phases in alcoholics in acute withdrawal (n=23), the normalisation of cortisol output in abstinent alcoholics (n=25) and cortisol levels in age- and gender-matched controls (n=20). Scalp-near 3-cm hair segments were sampled and analysed for cortisol content. Results showed three to fourfold higher cortisol levels in hair samples of alcoholics in acute withdrawal than in those of abstinent alcoholics (p<.001) or controls (p<.001), with no differences between the latter two groups. The current hair cortisol findings closely mirror results of previous research using well-established measures of systemic cortisol secretion and thus provide further validation of this novel method. PMID:20727937

  14. Hair Care

    MedlinePlus

    ... Body Looking and feeling your best Hair care Hair care Short, long, curly, straight, up, down. Hair options can seem endless! Not all of what makes your hair look good comes from the outside, though. Good ...

  15. Oily hair

    MedlinePlus

    Hair - oily ... are some tips for preventing and treating oily hair: Shampoo your hair every day. Leaving the shampoo on your head ... minutes before rinsing may help. Avoid brushing your hair too often or too vigorously, since the brushing ...

  16. Hair Transplants

    MedlinePlus

    ... How to Choose the Best Skin Care Products Hair Transplants What are hair transplants? In punch transplanting, a plug containing hair ... What should first be done before considering a hair transplant? Before the procedure, an ASDS doctor will ...

  17. Exploring the Role of Mechanotransduction Activation and Adaptation Kinetics in Hair Cell Filtering Using a Hodgkin-Huxley Approach

    NASA Astrophysics Data System (ADS)

    Wells, Gregg B.; Ricci, Anthony J.

    2011-11-01

    In the auditory system, mechanotransduction occurs in the hair cell sensory hair bundle and is the first major step in the translation of mechanical energy into electrical. Tonotopic variations in the activation kinetics of this process are posited to provide a low pass filter to the input. An adaptation process, also associated with mechanotransduction, is postulated to provide a high pass filter to the input in a tonotopic manner. Together a bandpass filter is created at the hair cell input. Corresponding mechanical components to both activation and adaptation are also suggested to be involved in generating cochlear amplification. A paradox to this story is that hair cells where the mechanotransduction properties are most robust possess an intrinsic electrical resonance mechanism proposed to account for all required tuning and amplification. A simple Hodgkin-Huxley type model is presented to attempt to determine the role of the activation and adaptation kinetics in further tuning hair cells that exhibit electrical resonance. Results further support that steady state mechanotransduction properties are critical for setting the resting potential of the hair cell while the kinetics of activation and adaptation are important for sharpening tuning around the characteristic frequency of the hair cell.

  18. Cyclic dermal BMP signalling regulates stem cell activation during hair regeneration.

    PubMed

    Plikus, Maksim V; Mayer, Julie Ann; de la Cruz, Damon; Baker, Ruth E; Maini, Philip K; Maxson, Robert; Chuong, Cheng-Ming

    2008-01-17

    In the age of stem cell engineering it is critical to understand how stem cell activity is regulated during regeneration. Hairs are mini-organs that undergo cyclic regeneration throughout adult life, and are an important model for organ regeneration. Hair stem cells located in the follicle bulge are regulated by the surrounding microenvironment, or niche. The activation of such stem cells is cyclic, involving periodic beta-catenin activity. In the adult mouse, regeneration occurs in waves in a follicle population, implying coordination among adjacent follicles and the extrafollicular environment. Here we show that unexpected periodic expression of bone morphogenetic protein 2 (Bmp2) and Bmp4 in the dermis regulates this process. This BMP cycle is out of phase with the WNT/beta-catenin cycle, thus dividing the conventional telogen into new functional phases: one refractory and the other competent for hair regeneration, characterized by high and low BMP signalling, respectively. Overexpression of noggin, a BMP antagonist, in mouse skin resulted in a markedly shortened refractory phase and faster propagation of the regenerative wave. Transplantation of skin from this mutant onto a wild-type host showed that follicles in donor and host can affect their cycling behaviours mutually, with the outcome depending on the equilibrium of BMP activity in the dermis. Administration of BMP4 protein caused the competent region to become refractory. These results show that BMPs may be the long-sought 'chalone' inhibitors of hair growth postulated by classical experiments. Taken together, results presented in this study provide an example of hierarchical regulation of local organ stem cell homeostasis by the inter-organ macroenvironment. The expression of Bmp2 in subcutaneous adipocytes indicates physiological integration between these two thermo-regulatory organs. Our findings have practical importance for studies using mouse skin as a model for carcinogenesis, intra-cutaneous drug

  19. Coupling and Elastic Loading Affect the Active Response by the Inner Ear Hair Cell Bundles

    PubMed Central

    Strimbu, Clark Elliott; Fredrickson-Hemsing, Lea; Bozovic, Dolores

    2012-01-01

    Active hair bundle motility has been proposed to underlie the amplification mechanism in the auditory endorgans of non-mammals and in the vestibular systems of all vertebrates, and to constitute a crucial component of cochlear amplification in mammals. We used semi-intact in vitro preparations of the bullfrog sacculus to study the effects of elastic mechanical loading on both natively coupled and freely oscillating hair bundles. For the latter, we attached glass fibers of different stiffness to the stereocilia and observed the induced changes in the spontaneous bundle movement. When driven with sinusoidal deflections, hair bundles displayed phase-locked response indicative of an Arnold Tongue, with the frequency selectivity highest at low amplitudes and decreasing under stronger stimulation. A striking broadening of the mode-locked response was seen with increasing stiffness of the load, until approximate impedance matching, where the phase-locked response remained flat over the physiological range of frequencies. When the otolithic membrane was left intact atop the preparation, the natural loading of the bundles likewise decreased their frequency selectivity with respect to that observed in freely oscillating bundles. To probe for signatures of the active process under natural loading and coupling conditions, we applied transient mechanical stimuli to the otolithic membrane. Following the pulses, the underlying bundles displayed active movement in the opposite direction, analogous to the twitches observed in individual cells. Tracking features in the otolithic membrane indicated that it moved in phase with the bundles. Hence, synchronous active motility evoked in the system of coupled hair bundles by external input is sufficient to displace large overlying structures. PMID:22479461

  20. Coupling and elastic loading affect the active response by the inner ear hair cell bundles.

    PubMed

    Strimbu, Clark Elliott; Fredrickson-Hemsing, Lea; Bozovic, Dolores

    2012-01-01

    Active hair bundle motility has been proposed to underlie the amplification mechanism in the auditory endorgans of non-mammals and in the vestibular systems of all vertebrates, and to constitute a crucial component of cochlear amplification in mammals. We used semi-intact in vitro preparations of the bullfrog sacculus to study the effects of elastic mechanical loading on both natively coupled and freely oscillating hair bundles. For the latter, we attached glass fibers of different stiffness to the stereocilia and observed the induced changes in the spontaneous bundle movement. When driven with sinusoidal deflections, hair bundles displayed phase-locked response indicative of an Arnold Tongue, with the frequency selectivity highest at low amplitudes and decreasing under stronger stimulation. A striking broadening of the mode-locked response was seen with increasing stiffness of the load, until approximate impedance matching, where the phase-locked response remained flat over the physiological range of frequencies. When the otolithic membrane was left intact atop the preparation, the natural loading of the bundles likewise decreased their frequency selectivity with respect to that observed in freely oscillating bundles. To probe for signatures of the active process under natural loading and coupling conditions, we applied transient mechanical stimuli to the otolithic membrane. Following the pulses, the underlying bundles displayed active movement in the opposite direction, analogous to the twitches observed in individual cells. Tracking features in the otolithic membrane indicated that it moved in phase with the bundles. Hence, synchronous active motility evoked in the system of coupled hair bundles by external input is sufficient to displace large overlying structures. PMID:22479461

  1. 75 FR 3915 - Environmental Documents Prepared in Support of Sand and Gravel Activities on the Outer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-25

    ... Minerals Management Service Environmental Documents Prepared in Support of Sand and Gravel Activities on... for three sand and gravel activities proposed on the Outer Continental Shelf (OCS) and described in... noncompetitive basis, the rights to OCS sand, gravel, or shell resources for shore protection, beach or...

  2. 32P measurement and dose conversion factor evaluation of activated human hair by criticality accident.

    PubMed

    Yoon, Seokwon; Ha, Wi-Ho; Park, Seyoung; Shin, Seongwook; Yoo, Jaeryong; Park, Sunhoo; Lee, Seung-Sook

    2014-10-01

    In order to conduct dose assessment of victims in criticality accidents, a method of fast neutron capture-activated (32)P measurement of hair in which samples are treated by a chemical and analytical procedure that takes 9 h and measurement is conducted by liquid scintillation counting is presented. To validate this measurement method, hair samples spiked with a (32)P reference source were measured and the results analysed and the optimal sample mass and detection efficiency were determined. To verify the correlation between (32)P-specific activity and absorbed dose for spectra with two neutron mean energies, samples collected from three normal individuals were irradiated at various neutron energies and irradiation times using the MC50 Cyclotron of the Korea Institute of Radiological and Medical Sciences. The (32)P-specific activity trend of the irradiated hair agreed well with the absorbed doses. Based on the results, dose conversion factors, which were 0.67 ± 0.15 and 0.59 ± 0.06 Gy (Bq g(-1))(-1) at neutron mean energies of 2.33 and 5.36 MeV, respectively, were calculated as a guide for medical treatment of criticality accident victims. PMID:24516187

  3. ULTRASTRUCTURE OF VEILLONELLA AND MORPHOLOGICAL CORRELATION OF AN OUTER MEMBRANE WITH PARTICLES ASSOCIATED WITH ENDOTOXIC ACTIVITY

    PubMed Central

    Bladen, Howard A.; Mergenhagen, Stephan E.

    1964-01-01

    Bladen, Howard A. (National Institute of Dental Research, Bethesda, Md.), and Stephan E. Mergenhagen. Ultrastructure of Veillonella and morphological correlation of an outer membrane with particles associated with endotoxic activity. J. Bacteriol. 88:1482–1492. 1964.—Normal, phenol-water extracted, and lysozyme-treated Veillonella cells were embedded in Vestopal W, sectioned, and examined by electron microscopy. Normal cells as well as the phenol-water extract (endotoxin) were examined by negative and positive contrast techniques. In thin sections of normal cells, three separate structural entities were observed surrounding the protoplasm, and were referred to as the outer membrane, the solid membrane, and the plasma membrane. The outer membrane was a membrane composed of two dense layers (30 A) separated by a less-dense layer (20 A), and followed a convoluted and continuous path around the cell. The solid membrane appeared as a taut, dense structure 100 to 500 A wide, and was separated from the outer membrane by up to several hundred Ångstroms. The plasma membrane was a unit-type membrane. After cells were treated with phenol-water, the outer membrane was absent, but the cells remained intact owing to the solid membrane. Observation of the phenol-water extract (endotoxin) revealed predominantly circular particles or discs which had approximately the same dimensions in height as the outer membrane had in width. Negatively stained whole cells showed similar structures on their surface. Lysozyme treatment of the cells did not affect the outer membrane; however, the solid membrane became diffuse and often disappeared, suggesting that the outer membrane and the solid membrane were separate structures. Images PMID:14234809

  4. Mechanical overstimulation of hair bundles: suppression and recovery of active motility.

    PubMed

    Kao, Albert; Meenderink, Sebastiaan W F; Bozovic, Dolores

    2013-01-01

    We explore the effects of high-amplitude mechanical stimuli on hair bundles of the bullfrog sacculus. Under in vitro conditions, these bundles exhibit spontaneous limit cycle oscillations. Prolonged deflection exerted two effects. First, it induced an offset in the position of the bundle. Recovery to the original position displayed two distinct time scales, suggesting the existence of two adaptive mechanisms. Second, the stimulus suppressed spontaneous oscillations, indicating a change in the hair bundle's dynamic state. After cessation of the stimulus, active bundle motility recovered with time. Both effects were dependent on the duration of the imposed stimulus. External calcium concentration also affected the recovery to the oscillatory state. Our results indicate that both offset in the bundle position and calcium concentration control the dynamic state of the bundle. PMID:23505461

  5. Mechanical Overstimulation of Hair Bundles: Suppression and Recovery of Active Motility

    PubMed Central

    Kao, Albert; Meenderink, Sebastiaan W. F.; Bozovic, Dolores

    2013-01-01

    We explore the effects of high-amplitude mechanical stimuli on hair bundles of the bullfrog sacculus. Under in vitro conditions, these bundles exhibit spontaneous limit cycle oscillations. Prolonged deflection exerted two effects. First, it induced an offset in the position of the bundle. Recovery to the original position displayed two distinct time scales, suggesting the existence of two adaptive mechanisms. Second, the stimulus suppressed spontaneous oscillations, indicating a change in the hair bundle’s dynamic state. After cessation of the stimulus, active bundle motility recovered with time. Both effects were dependent on the duration of the imposed stimulus. External calcium concentration also affected the recovery to the oscillatory state. Our results indicate that both offset in the bundle position and calcium concentration control the dynamic state of the bundle. PMID:23505461

  6. 78 FR 48180 - Consolidation of Officer in Charge, Marine Inspection For Outer Continental Shelf Activities...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-07

    ... SECURITY Coast Guard Consolidation of Officer in Charge, Marine Inspection For Outer Continental Shelf Activities; Eighth Coast Guard District AGENCY: Coast Guard, DHS. ACTION: Notice and request for comments. SUMMARY: The Coast Guard is considering establishing a single Officer in Charge, Marine Inspection...

  7. 77 FR 5830 - Commercial Wind Leasing and Site Assessment Activities on the Atlantic Outer Continental Shelf...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-06

    ... FR 30,616) of the EA for Issuance of Leases for Wind Resource Data Collection on the Outer... (NOA) in the Federal Register (72 FR 62,672) of the Programmatic EIS for Alternative Energy Development... Bureau of Ocean Energy Management Commercial Wind Leasing and Site Assessment Activities on the...

  8. 78 FR 5836 - Adjustment of Service Fees for Outer Continental Shelf Activities

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-28

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Adjustment of Service Fees for Outer Continental Shelf Activities... updated in 2008, with Federal Register Notice 73 FR 49943. BOEM is now adjusting various cost...

  9. Atlantic update, July 1986--June 1990: Outer Continental Shelf oil and gas activities

    SciTech Connect

    Karpas, R.M.; Gould, G.J.

    1990-10-01

    This report describes outer continental shelf oil and gas activities in the Atlantic Region. This edition of the Atlantic Update includes an overview of the Mid-Atlantic Planning Area and a summary of the Manteo Prospect off-shore North Carolina. 6 figs., 8 tabs.

  10. Preliminary characterization of voltage-activated whole-cell currents in developing human vestibular hair cells and calyx afferent terminals.

    PubMed

    Lim, Rebecca; Drury, Hannah R; Camp, Aaron J; Tadros, Melissa A; Callister, Robert J; Brichta, Alan M

    2014-10-01

    We present preliminary functional data from human vestibular hair cells and primary afferent calyx terminals during fetal development. Whole-cell recordings were obtained from hair cells or calyx terminals in semi-intact cristae prepared from human fetuses aged between 11 and 18 weeks gestation (WG). During early fetal development (11-14 WG), hair cells expressed whole-cell conductances that were qualitatively similar but quantitatively smaller than those observed previously in mature rodent type II hair cells. As development progressed (15-18 WG), peak outward conductances increased in putative type II hair cells but did not reach amplitudes observed in adult human hair cells. Type I hair cells express a specific low-voltage activating conductance, G K,L. A similar current was first observed at 15 WG but remained relatively small, even at 18 WG. The presence of a "collapsing" tail current indicates a maturing type I hair cell phenotype and suggests the presence of a surrounding calyx afferent terminal. We were also able to record from calyx afferent terminals in 15-18 WG cristae. In voltage clamp, these terminals exhibited fast inactivating inward as well as slower outward conductances, and in current clamp, discharged a single action potential during depolarizing steps. Together, these data suggest the major functional characteristics of type I and type II hair cells and calyx terminals are present by 18 WG. Our study also describes a new preparation for the functional investigation of key events that occur during maturation of human vestibular organs. PMID:24942706

  11. Outer-sphere residues influence the catalytic activity of a chalcone synthase from Polygonum cuspidatum.

    PubMed

    Shen, Yalin; Li, Xing; Chai, Tuanyao; Wang, Hong

    2016-06-01

    We have previously cloned a chalcone synthase (PcCHS1) from Polygonum cuspidatum and biochemically identified its enzymatic dynamic properties. Here, we found that the outer sphere residues, Q82 and R105, could affect the catalytic activity and product profile of PcCHS1. Both Q82P and R105Q mutations of PcCHS1 could also change the pH dependence activity as well as the product profile of PcCHS1. Moreover, the Q82P/C198F double mutant could rescue the complete loss of enzyme activity caused by the C198F single mutation. Our study demonstrated that these outer-sphere residues of PcCHS1 play important roles both in structural maintenance and enzyme activity. PMID:27419064

  12. Hair Removal

    MedlinePlus

    ... maintain a steady temperature by providing some insulation. Terminal hair is coarser, darker, and longer than vellus ... hair that grows on your head. Around puberty, terminal hair starts to grow in the armpits and ...

  13. Hair transplant

    MedlinePlus

    Hair restoration ... MR, Keene SA, Stough DB, Rogers NE. Hair restoration. In: Bolognia JL, Jorizzo JL, Schaffer JV, eds. ... Elsevier Saunders; 2012:chap 157. Fisher J. Hair restoration. In: Neligan PC, ed. Plastic Surgery . 3rd ed. ...

  14. Dry hair

    MedlinePlus

    Some causes of dry hair are: Anorexia nervosa Excessive hair washing, or using harsh soaps or alcohols Excessive blow-drying Dry air Menkes kinky hair syndrome Malnutrition Underactive parathyroid ( ...

  15. Hair loss

    MedlinePlus

    ... that is applied to the scalp to stimulate hair growth. Other medicines, such as hormones, may be prescribed to decrease hair loss and promote hair growth. Drugs such as finasteride and dutasteride can be ...

  16. Hair Dye and Hair Relaxers

    MedlinePlus

    ... For Consumers Consumer Information by Audience For Women Hair Dye and Hair Relaxers Share Tweet Linkedin Pin it More sharing ... products. If you have a bad reaction to hair dyes and relaxers, you should: Stop using the ...

  17. STAT5 Activation in the Dermal Papilla Is Important for Hair Follicle Growth Phase Induction.

    PubMed

    Legrand, Julien M D; Roy, Edwige; Ellis, Jonathan J; Francois, Mathias; Brooks, Andrew J; Khosrotehrani, Kiarash

    2016-09-01

    Hair follicles are skin appendages that undergo periods of growth (anagen), regression (catagen), and rest (telogen) regulated by their mesenchymal component, the dermal papilla (DP). On the basis of the reports of its specific expression in the DP, we investigated signal transducer and activator of transcription (STAT5) activation during hair development and cycling. STAT5 activation in the DP began in late catagen, reaching a peak in early anagen before disappearing for the rest of the cycle. This was confirmed by the expression profile of suppressor of cytokine signaling 2, a STAT5 target in the DP. This pattern of expression starts after the first postnatal hair cycle. Quantification of hair cycling using the Flash canonical Wnt signaling in vivo bioluminescence reporter found that conditional knockout of STAT5A/B in the DP targeted through Cre-recombinase under the control of the Sox18 promoter resulted in delayed anagen entry compared with control. Microarray analysis of STAT5 deletion versus control revealed key changes in tumor necrosis factor-α, Wnt, and fibroblast growth factor ligands, known for their role in inducing anagen entry. We conclude that STAT5 activation acts as a mesenchymal switch to trigger natural anagen entry in postdevelopmental hair follicle cycling. PMID:27131881

  18. Plant Growth Promotion Activity of Keratinolytic Fungi Growing on a Recalcitrant Waste Known as "Hair Waste".

    PubMed

    Cavello, Ivana A; Crespo, Juan M; García, Sabrina S; Zapiola, José M; Luna, María F; Cavalitto, Sebastián F

    2015-01-01

    Purpureocillium lilacinum (Thom) Samsom is one of the most studied fungi in the control of plant parasitic nematodes. However, there is not specific information on its ability to inhibit some pathogenic bacteria, fungi, or yeast. This work reports the production of several antifungal hydrolytic enzymes by a strain of P. lilacinum when it is grown in a medium containing hair waste. The growth of several plant-pathogenic fungi, Alternaria alternata, Aspergillus niger, and Fusarium culmorum, was considerably affected by the presence of P. lilacinum's supernatant. Besides antifungal activity, P. lilacinum demonstrates the capability to produce indoleacetic acid and ammonia during time cultivation on hair waste medium. Plant growth-promoting activity by cell-free supernatant was evidenced through the increase of the percentage of tomato seed germination from 71 to 85% after 48 hours. A 21-day plant growth assay using tomato plants indicates that crude supernatant promotes the growth of the plants similar to a reference fertilizer (p > 0.05). These results suggest that both strain and the supernatant may have potential to be considered as a potent biocontrol agent with multiple plant growth-promoting properties. To our knowledge, this is the first report on the antifungal, IAA production and tomato growth enhancing compounds produced by P. lilacinum LPSC #876. PMID:26697226

  19. Porin activity of the native and recombinant outer membrane protein Oms28 of Borrelia burgdorferi.

    PubMed Central

    Skare, J T; Champion, C I; Mirzabekov, T A; Shang, E S; Blanco, D R; Erdjument-Bromage, H; Tempst, P; Kagan, B L; Miller, J N; Lovett, M A

    1996-01-01

    The outer membrane-spanning (Oms) proteins of Borrelia burgdorferi have been visualized by freeze-fracture analysis but, until recently, not further characterized. We developed a method for the isolation of B. burgdorferi outer membrane vesicles and described porin activities with single-channel conductances of 0.6 and 12.6 nS in 1 M KCI. By using both nondenaturing isoelectric focusing gel electrophoresis and fast-performance liquid chromatography separation after detergent solubilization, we found that the 0.6-nS porin activity resided in a 28-kDa protein, designated Oms28. The oms28 gene was cloned, and its nucleotide sequence was determined. The deduced amino acid sequence of Oms28 predicted a 257-amino-acid precursor protein with a putative 24-amino-acid leader peptidase I signal sequence. Processed Oms28 yielded a mature protein with a predicted molecular mass of 25,363 Da. When overproduced in Escherichia coli, the Oms28 porin fractionated in part to the outer membrane. Sodium dodecyl sulfate-polyacrylamide gel-purified recombinant Oms28 from E. coli retained functional activity as demonstrated by an average single-channel conductance of 1.1 nS in the planar lipid bilayer assay. These findings confirmed that Oms28 is a B. burgdorferi porin, the first to be described. As such, it is potential relevance to the pathogenesis of Lyme borreliosis and to the physiology of the spirochete. PMID:8759855

  20. Hair transplantation.

    PubMed

    Avram, Marc R

    2012-12-01

    Hair transplantation is a purely dermatologic surgical procedure that dermatologists should be able to perform in appropriate candidates with hair loss. Hair transplantation techniques performed in the 1960s through the 1990s utilized large grafts that created an unfortunate public image of unnatural-appearing transplanted hair. Over the last 15 years, hair transplantation has been performed using follicular units to create consistently natural-looking transplanted hair in both men and women. This article provides an overview of candidate selection and state-of-the-art techniques for performing hair transplantation. PMID:23409484

  1. Bipedality and hair loss in human evolution revisited: The impact of altitude and activity scheduling.

    PubMed

    Dávid-Barrett, Tamás; Dunbar, Robin I M

    2016-05-01

    Bipedality evolved early in hominin evolution, and at some point was associated with hair loss over most of the body. One classic explanation (Wheeler 1984: J. Hum. Evol. 13, 91-98) was that these traits evolved to reduce heat overload when australopiths were foraging in more open tropical habitats where they were exposed to the direct effects of sunlight at midday. A recent critique of this model (Ruxton & Wilkinson 2011a: Proc. Natl. Acad. Sci. USA 108, 20965-20969) argued that it ignored the endogenous costs of heat generated by locomotion, and concluded that only hair loss provided a significant reduction in heat load. We add two crucial corrections to this model (the altitude at which australopiths actually lived and activity scheduling) and show that when these are included there are substantial reductions in heat load for bipedal locomotion even for furred animals. In addition, we add one further consideration to the model: we extend the analysis across the full 24 h day, and show that fur loss could not have evolved until much later because of the thermoregulatory costs this would have incurred at the altitudes where australopiths actually lived. Fur loss is most likely associated with the exploitation of open habitats at much lower altitudes at a much later date by the genus Homo. PMID:27178459

  2. Mercury determination in hair of Malaysian fishermen by neutron activation analysis.

    PubMed

    Sarmani, S B; Kiprawi, A Z; Ismail, R B

    1994-01-01

    Fish has been known as a source of nonoccupational mercury exposure to fish-consuming population groups. In this study, hair samples collected from fishermen and their families residing in an industrialized area in Penang and a nonindustrialized area in Terengganu were analyzed for mercury by neutron activation. The range, arithmetic mean, geometric mean, and median of the mercury concentrations for the groups in Penang and in Terengganu were 0.45-16.68, 3.61, 3.49, and 2.96 and 6.79-18.31, 12.08, 11.69, and 12.05 mg/kg, respectively. Somewhat lower values than from the Penang group were found in a group from Selangor consisting mainly of office workers. The group in Penang took about 40-100 g of fish/d, whereas the group in Terengganu consumed twice as much. This shows that hair mercury levels depend on a fish consumption pattern, and not on the location of the population. The levels of mercury found in this study were similar to those reported by other workers for fish-consuming population groups worldwide. PMID:7710858

  3. Localizations of γ-Actins in Skin, Hair, Vibrissa, Arrector Pili Muscle and Other Hair Appendages of Developing Rats

    PubMed Central

    Morioka, Kiyokazu; Takano-Ohmuro, Hiromi

    2016-01-01

    Six isoforms of actins encoded by different genes have been identified in mammals including α-cardiac, α-skeletal, α-smooth muscle (α-SMA), β-cytoplasmic, γ-smooth muscle (γ-SMA), and γ-cytoplasmic actins (γ-CYA). In a previous study we showed the localization of α-SMA and other cytoskeletal proteins in the hairs and their appendages of developing rats (Morioka K., et al. (2011) Acta Histochem. Cytochem. 44, 141–153), and herein we determined the localization of γ type actins in the same tissues and organs by immunohistochemical staining. Our results indicate that the expression of γ-SMA and γ-CYA is suggested to be poor in actively proliferating tissues such as the basal layer of the epidermis and the hair matrix in the hair bulb, and as well as in highly keratinized tissues such as the hair cortex and hair cuticle. In contrast, the expression of γ-actins were high in the spinous layer, granular layer, hair shaft, and inner root sheath, during their active differentiations. In particular, the localization of γ-SMA was very similar to that of α-SMA. It was located not only in the arrector pili muscles and muscles in the dermis, but also in the dermal sheath and in a limited area of the outer root sheath in both the hair and vibrissal follicles. The γ-CYA was suggested to be co-localized with γ-SMA in the dermal sheath, outer root sheath, and arrector pili muscles. Sparsely distributed dermal cells expressed both types of γ-actin. The expression of γ-actins is suggested to undergo dynamic changes according to the proliferation and differentiation of the skin and hair-related cells. PMID:27222613

  4. Root hairs play a key role in the endophytic colonization of olive roots by Pseudomonas spp. with biocontrol activity.

    PubMed

    Prieto, Pilar; Schilirò, Elisabetta; Maldonado-González, María Mercedes; Valderrama, Raquel; Barroso-Albarracín, Juan Bautista; Mercado-Blanco, Jesús

    2011-08-01

    The use of indigenous bacterial root endophytes with biocontrol activity against soil-borne phytopathogens is an environmentally-friendly and ecologically-efficient action within an integrated disease management framework. The earliest steps of olive root colonization by Pseudomonas fluorescens PICF7 and Pseudomonas putida PICP2, effective biocontrol agents (BCAs) against Verticillium wilt of olive (Olea europaea L.) caused by the fungus Verticillium dahliae Kleb., are here described. A gnotobiotic study system using in vitro propagated olive plants, differential fluorescent-protein tagging of bacteria, and confocal laser scanning microscopy analysis have been successfully used to examine olive roots-Pseudomonas spp. interactions at the single-cell level. In vivo simultaneous visualization of PICF7 and PICP2 cells on/in root tissues enabled to discard competition between the two bacterial strains during root colonization. Results demonstrated that both BCAs are able to endophytically colonized olive root tissues. Moreover, results suggest a pivotal role of root hairs in root colonization by both biocontrol Pseudomonas spp. However, colonization of root hairs appeared to be a highly specific event, and only a very low number of root hairs were effectively colonized by introduced bacteria. Strains PICF7 and PICP2 can simultaneously colonize the same root hair, demonstrating that early colonization of a given root hair by one strain did not hinder subsequent attachment and penetration by the other. Since many environmental factors can affect the number, anatomy, development, and physiology of root hairs, colonization competence and biocontrol effectiveness of BCAs may be greatly influenced by root hair's fitness. Finally, the in vitro study system here reported has shown to be a suitable tool to investigate colonization processes of woody plant roots by microorganisms with biocontrol potential. PMID:21347721

  5. The Growth of Human Hair.

    ERIC Educational Resources Information Center

    Jones, Helen J.

    1984-01-01

    Suggests a simple technique for collecting and observing human hair roots to compare structure, function, and variation. Students extract their own hair samples and view them using a 40-power microscope objective. Differences between active/inactive phases of hair growth are readily observed. (The activity can be adapted for younger students.) (DH)

  6. [The life of human hair follicle revealed].

    PubMed

    Bernard, Bruno A

    2006-02-01

    The human hair follicle is a unique appendage which results from epithelio-mesenchymal interactions initiated around the 3rd month of development. This appendage has a very complex structure, with a dermal compartment and an epithelial compartment. The dermal compartment comprises the connective tissue sheath and the dermal papilla, both of which are irrigated by microvessels. The epithelial compartment is made of highly replicating matrix cells giving rise to three concentrical domains, namely the outer root sheath, the inner root sheath and the hair shaft. The pigmentation unit, responsible for hair color, is made of fully active melanocytes located on top of the dermal papilla. Altogether a hair follicle contains more than 20 different cell types, engaged in different differentiation pathways and/or interacting with each other. This complex appendage has a unique behavior in mammals since, after a hair production phase, it involutes in place before entering a resting phase after which it renews itself under a cyclical but stochastic way, out of a double reservoir of pluripotent stem cells able to also regenerate epidermis. For yet unknown reasons, this well ordered process can be disturbed, provoking alopecia. The pigmentation unit also renews itself under a cyclical way, out of a melanocyte progenitor reservoir which progressively declines with time, provoking the hair whitening process. Finally, the shape of the hair shaft is programmed from the bulb. What makes this appendage unique and fascinating is its high degree of autonomy, its incredibly complex though stable structure, the number of different cell types interacting under an equilibrated way and its potential of regeneration. It represents a true paradigm of tissue homeostasis, exemplifying in a small living cylinder all the fundamental laws of cell-cell and tissue interactions. This life is revealed in this short synthesis. PMID:16457752

  7. Growth and viability of Liaoning Cashmere goat hair follicles during the annual hair follicle cycle.

    PubMed

    Zhang, Q L; Li, J P; Chen, Y; Chang, Q; Li, Y M; Yao, J Y; Jiang, H Z; Zhao, Z H; Guo, D

    2014-01-01

    Here, we studied hair follicle development of Liaoning Cashmere goats. Every month for 1 year, skin samples were collected from five 1.5-year-old female goats, and made into paraffin sections. A number of parameters were measured of primary and secondary hair follicles via microscopic observation including follicle depth, hair bulb width, dermis and epidermis thickness, changes in follicle activity, and histology. The results showed the presence of three phases in the annual hair cycle: anagen, catagen, and telogen. Primary and secondary hair follicle depth varied across the months; however, no significant difference was obtained between adjacent months (P>0.05). Primary hair follicles had a bigger hair bulb width compared to secondary hair follicles; however, this difference declined during hair follicle developed in anagen. As hair follicle growth slowed, the hair bulb broadened, and hair root depth became shallower. During the entire hair cycle, hair follicle depth and dermis thickness were positively correlated; however, this relationship was not significant (P>0.05) for primary and secondary hair follicle density and the ratio of secondary hair follicle density and primary hair follicle density (S/P ratio). In addition, new and old primary hair follicles coexisted with secondary hair follicles. Finally, secondary hair follicles had a higher activity rate compared to primary hair follicle in adult Liaoning Cashmere goats in certain months. PMID:25036348

  8. Hair growth promoting activity of Eclipta alba in male albino rats.

    PubMed

    Roy, R K; Thakur, Mayank; Dixit, V K

    2008-08-01

    Alopecia is a dermatological disorder with psychosocial implications on patients with hair loss. Eclipta alba Hassk. is a well-known Ayurvedic herb with purported claims of hair growth promotion. In the reported work attempts were undertaken to evaluate petroleum ether and ethanol extract of E. alba Hassk. for their effect on promoting hair growth in albino rats. The extracts were incorporated into oleaginous cream (water in oil cream base) and applied topically on shaved denuded skin of albino rats. The time (in days) required for hair growth initiation as well as completion of hair growth cycle was recorded. Minoxidil 2% solution was applied topically and served as positive control for comparison. Hair growth initiation time was significantly reduced to half on treatment with the extracts, as compared to control animals. The time required for complete hair growth was also significantly reduced. Quantitative analysis of hair growth after treatment with petroleum ether extract (5%) exhibited greater number of hair follicles in anagenic phase (69 +/- 4) which were higher as compared to control (47 +/- 13). The result of treatment with 2 and 5% petroleum ether extracts were better than the positive control minoxidil 2% treatment. PMID:18478241

  9. Doppler laser imaging predicts response to topical minoxidil in the treatment of female pattern hair loss.

    PubMed

    McCoy, J; Kovacevic, M; Situm, M; Stanimirovic, A; Bolanca, Z; Goren, A

    2016-01-01

    Topical minoxidil is the only drug approved by the US FDA for the treatment of female pattern hair loss. Unfortunately, following 16 weeks of daily application, less than 40% of patients regrow hair. Several studies have demonstrated that sulfotransferase enzyme activity in plucked hair follicles predicts topical minoxidil response in female pattern hair loss patients. However, due to patients’ discomfort with the procedure, and the time required to perform the enzymatic assay it would be ideal to develop a rapid, non-invasive test for sulfotransferase enzyme activity. Minoxidil is a pro-drug converted to its active form, minoxidil sulfate, by sulfotransferase enzymes in the outer root sheath of hair. Minoxidil sulfate is the active form required for both the promotion of hair regrowth and the vasodilatory effects of minoxidil. We thus hypothesized that laser Doppler velocimetry measurement of scalp blood perfusion subsequent to the application of topical minoxidil would correlate with sulfotransferase enzyme activity in plucked hair follicles. In this study, plucked hair follicles from female pattern hair loss patients were analyzed for sulfotransferase enzyme activity. Additionally, laser Doppler velocimetry was used to measure the change in scalp perfusion at 15, 30, 45, and 60 minutes, after the application of minoxidil. In agreement with our hypothesis, we discovered a correlation (r=1.0) between the change in scalp perfusion within 60 minutes after topical minoxidil application and sulfotransferase enzyme activity in plucked hairs. To our knowledge, this is the first study demonstrating the feasibility of using laser Doppler imaging as a rapid, non-invasive diagnostic test to predict topical minoxidil response in the treatment of female pattern hair loss. PMID:27049083

  10. Flame Hair

    PubMed Central

    Miteva, Mariya; Tosti, Antonella

    2015-01-01

    Background ‘Flame hairs’ is a trichoscopic feature described as hair residue from pulling anagen hairs in trichotillomania. Objective: To detect whether flame hairs are present in other hair loss disorders. Methods We retrospectively, independently and blindly reviewed the trichoscopic images of 454 consecutive patients with alopecia areata (99 cases), trichotillomania (n = 20), acute chemotherapy-induced alopecia (n = 6), acute radiotherapy-induced alopecia (n = 2), tinea capitis (n = 13), lichen planopilaris (n = 33), frontal fibrosing alopecia (n = 60), discoid lupus erythematosus (n = 30), dissecting cellulitis (n = 11), central centrifugal cicatricial alopecia (n = 94) and traction alopecia (n = 86) for the presence of flame hairs. We prospectively obtained trichoscopy-guided scalp biopsies from flame hairs in trichotillomania, alopecia areata, traction alopecia and central centrifugal cicatricial alopecia (1 case each). Results Flame hairs were detected in 100% of the acute chemotherapy- and radiotherapy-induced alopecias, where they were the predominant hair abnormality. They were also found in trichotillomania (55%), alopecia areata (21%), traction alopecia (4%) and central centrifugal cicatricial alopecia (3%). On pathology, they corresponded to distorted hair shafts. Conclusion The flame hair is a type of broken hair which can be seen in various hair loss disorders. It results from traumatic pulling of anagen hairs or from anagen arrest due to inflammation or drugs. © 2015 S. Karger AG, Basel PMID:27171360

  11. A Hot New Twist to Hair Biology

    PubMed Central

    Bodó, Enikő; Bíró, Tamás; Telek, Andrea; Czifra, Gabriella; Griger, Zoltán; Tóth, Balázs I.; Mescalchin, Alessandra; Ito, Taisuke; Bettermann, Albrecht; Kovács, László; Paus, Ralf

    2005-01-01

    The vanilloid receptor-1 (VR1, or transient receptor potential vanilloid-1 receptor, TRPV1) is activated by capsaicin, the key ingredient of hot peppers. TRPV1 was originally described on sensory neurons as a central integrator of various nociceptive stimuli. However, several human skin cell populations are also now recognized to express TRPV1, but with unknown function. Exploiting the human hair follicle (HF) as a prototypic epithelial-mesenchymal interaction system, we have characterized the HF expression of TRPV1 in situ and have examined TRPV1 signaling in organ-cultured human scalp HF and outer root sheath (ORS) keratinocytes in vitro. TRPV1 immunoreactivity was confined to distinct epithelial compartments of the human HF, mainly to the ORS and hair matrix. In organ culture, TRPV1 activation by capsaicin resulted in a dose-dependent and TRPV1-specific inhibition of hair shaft elongation, suppression of proliferation, induction of apoptosis, premature HF regression (catagen), and up-regulation of intrafollicular transforming growth factor-β2. Cultured human ORS keratinocytes also expressed functional TRPV1, whose stimulation inhibited proliferation, induced apoptosis, elevated intracellular calcium concentration, up-regulated known endogenous hair growth inhibitors (interleukin-1β, transforming growth factor-β2), and down-regulated known hair growth promoters (hepatocyte growth factor, insulin-like growth factor-I, stem cell factor). These findings strongly support TRPV1 as a significant novel player in human hair growth control, underscore the physiological importance of TRPV1 in human skin beyond nociception, and identify TRPV1 as a promising, novel target for pharmacological manipulations of epithelial growth disorders. PMID:15793280

  12. Stellar Activity and Exclusion of the Outer Planet in the HD 99492 System

    NASA Astrophysics Data System (ADS)

    Kane, Stephen R.; Thirumalachari, Badrinath; Henry, Gregory W.; Hinkel, Natalie R.; Jensen, Eric L. N.; Boyajian, Tabetha S.; Fischer, Debra A.; Howard, Andrew W.; Isaacson, Howard T.; Wright, Jason T.

    2016-03-01

    A historical problem for indirect exoplanet detection has been contending with the intrinsic variability of the host star. If the variability is periodic, it can easily mimic various exoplanet signatures, such as radial velocity (RV) variations that originate with the stellar surface rather than the presence of a planet. Here we present an update for the HD 99492 planetary system, using new RV and photometric measurements from the Transit Ephemeris Refinement and Monitoring Survey. Our extended time series and subsequent analyses of the Ca ii H&K emission lines show that the host star has an activity cycle of ∼13 years. The activity cycle correlates with the purported orbital period of the outer planet, the signature of which is thus likely due to the host star activity. We further include a revised Keplerian orbital solution for the remaining planet, along with a new transit ephemeris. Our transit-search observations were inconclusive.

  13. Hair Changes

    MedlinePlus

    ... To get rid of unwanted hair growth: Tweeze, wax or shave, which are all safe during pregnancy. ... To get rid of unwanted hair growth: Tweeze, wax or shave, which are all safe during pregnancy. ...

  14. Hair Loss

    MedlinePlus

    ... may cause hair loss in women. If your hair loss has occurred gradually with advancing age, FOLLICULAR DEGENERATION may be the cause. Post-pregnancy hormone changes usually reverse themselves without any treatment. While follicular degeneration cannot ...

  15. Hair Loss

    MedlinePlus

    ... Common baldness" usually means male-pattern baldness, or permanent-pattern baldness. It is also called androgenetic alopecia. ... will grow back normally. However, scarring can cause permanent hair loss. Hot oil hair treatments or chemicals ...

  16. Hair Loss

    MedlinePlus

    ... are stress, a low protein diet, a family history, or poor nutrition. Treatment for hair loss depends on the cause. In some cases, treating the underlying cause will correct the problem. Other treatments include medicines and hair restoration.

  17. Hair loss

    MedlinePlus

    ... continual hair pulling or scalp rubbing Radiation therapy Tinea capitis (ringworm of the scalp) Tumor of the ovary or ... a plucked hair Skin biopsy If you have ringworm on the scalp, you may be prescribed an ...

  18. Influence of bacterial toxins on the GTPase activity of transducin from bovine retinal rod outer segments

    SciTech Connect

    Rybin, V.O.; Gureeva, A.A.

    1986-05-10

    The action of cholera toxin, capable of ADP-ribosylation of the activator N/sub s/ protein, and pertussis toxin, capable of ADP-ribosylation of the inhibitor N/sub i/ protein of the adenylate cyclase complex, on transducin, the GTP-binding protein of the rod outer segments of the retina, was investigated. It was shown that under the action of pertussis and cholera toxins, the GTPase activity of transducin is inhibited. Pertussin toxin inhibits the GTPase of native retinal rod outer segments by 30-40%, while GTPase of homogeneous transducin produces a 70-80% inhibition. The action of toxins on transducin depends on the presence and nature of the guanylic nucleotide with which incubation is performed. On the basis of the data obtained it is suggested that pertussis toxin interacts with pretransducin and with the transducin-GDP complex, while cholera toxin ADP-ribosylates the transducin-GTP complex and does not act on transducin lacking GTP.

  19. mTOR signaling promotes stem cell activation via counterbalancing BMP-mediated suppression during hair regeneration.

    PubMed

    Deng, Zhili; Lei, Xiaohua; Zhang, Xudong; Zhang, Huishan; Liu, Shuang; Chen, Qi; Hu, Huimin; Wang, Xinyue; Ning, Lina; Cao, Yujing; Zhao, Tongbiao; Zhou, Jiaxi; Chen, Ting; Duan, Enkui

    2015-02-01

    Hair follicles (HFs) undergo cycles of degeneration (catagen), rest (telogen), and regeneration (anagen) phases. Anagen begins when the hair follicle stem cells (HFSCs) obtain sufficient activation cues to overcome suppressive signals, mainly the BMP pathway, from their niche cells. Here, we unveil that mTOR complex 1 (mTORC1) signaling is activated in HFSCs, which coincides with the HFSC activation at the telogen-to-anagen transition. By using both an inducible conditional gene targeting strategy and a pharmacological inhibition method to ablate or inhibit mTOR signaling in adult skin epithelium before anagen initiation, we demonstrate that HFs that cannot respond to mTOR signaling display significantly delayed HFSC activation and extended telogen. Unexpectedly, BMP signaling activity is dramatically prolonged in mTOR signaling-deficient HFs. Through both gain- and loss-of-function studies in vitro, we show that mTORC1 signaling negatively affects BMP signaling, which serves as a main mechanism whereby mTORC1 signaling facilitates HFSC activation. Indeed, in vivo suppression of BMP by its antagonist Noggin rescues the HFSC activation defect in mTORC1-null skin. Our findings reveal a critical role for mTOR signaling in regulating stem cell activation through counterbalancing BMP-mediated repression during hair regeneration. PMID:25609845

  20. Your Hair

    MedlinePlus

    ... someone's hair, the less melanin there is. A person with brown or black hair has much more melanin than someone with ... example, many blondes have light skin, whereas many people with darker skin have dark brown or black hair. And don't forget genes (genes are ...

  1. A Bivalent Tarantula Toxin Activates the Capsaicin Receptor, TRPV1, by Targeting the Outer Pore Domain

    PubMed Central

    Bohlen, Christopher J.; Priel, Avi; Zhou, Sharleen; King, David; Siemens, Jan; Julius, David

    2010-01-01

    SUMMARY Toxins have evolved to target regions of membrane ion channels that underlie ligand binding, gating, or ion permeation, and have thus served as invaluable tools for probing channel structure and function. Here we describe a peptide toxin from the Earth Tiger tarantula that selectively and irreversibly activates the capsaicin- and heat-sensitive channel, TRPV1. This high avidity interaction derives from a unique tandem repeat structure of the toxin that endows it with an antibody-like bivalency, illustrating a new paradigm in toxin structure and evolution. The ‘double-knot’ toxin traps TRPV1 in the open state by interacting with residues in the presumptive pore-forming region of the channel, highlighting the importance of conformational changes in the outer pore region of TRP channels during activation. PMID:20510930

  2. Effect of Tectona grandis Linn. seeds on hair growth activity of albino mice.

    PubMed

    Jaybhaye, Deepali; Varma, Sushikumar; Gagne, Nitin; Bonde, Vijay; Gite, Amol; Bhosle, Deepak

    2010-10-01

    The seeds of Tectona grandis Linn. are traditionally acclaimed as hair tonic in the Indian system of medicine. Studies were therefore undertaken in order to evaluate petroleum ether extract of T. grandis seeds for its effect on hair growth in albino mice. The 5% and 10% extracts incorporated into simple ointment base were applied topically on shaved denuded skin of albino mice. The time required for initiation of hair growth as well as completion of hair growth cycle was recorded. Minoxidil 2% solution was applied topically and served as positive control. The result of treatment with minoxidil 2% is 49% hair in anagenic phase. Hair growth initiation time was significantly reduced to half on treatment with the extracts compared to control animals. The treatment was successful in bringing a greater number of hair follicles (64% and 51%) in anagenic phase than standard minoxidil (49%). The results of treatment with 5% and 10% petroleum ether extracts were comparable to the positive control minoxidil. PMID:21455447

  3. New activators and inhibitors in the hair cycle clock: targeting stem cells' state of competence.

    PubMed

    Plikus, Maksim V

    2012-05-01

    The timing mechanism of the hair cycle remains poorly understood. However, it has become increasingly clear that the telogen-to-anagen transition is controlled jointly by at least the bone morphogenic protein (BMP), WNT, fibroblast growth factor (FGF), and transforming growth factor (TGF)-β signaling pathways. New research shows that Fgf18 signaling in hair follicle stem cells synergizes BMP-mediated refractivity, whereas Tgf-β2 signaling counterbalances it. Loss of Fgf18 signaling markedly accelerates anagen initiation, whereas loss of Tgf-β2 signaling significantly delays it, supporting key roles for these pathways in hair cycle timekeeping. PMID:22499035

  4. Active stochastic oscillations and amplification of mechanical stimuli in a hair cell model

    NASA Astrophysics Data System (ADS)

    Han, Lijuan; Neiman, Alexander

    2009-03-01

    We study signal transduction in spontaneously oscillating hair bundles of an auditory hair cell using a computational model. The effects of intrinsic noise from the Brownian motion of hair bundles and from stochastic fluctuations of transduction ion channels as well as periodic fluctuations of the receptor potential are taken into account. The model shows the explosion of a canard trajectory near the Hopf bifurcation. We have found that the system's gain of weak mechanical stimuli can be greatly enhanced when the system operates slightly beyond the Hopf bifurcation, i.e. in the canard region. The gain can also be optimized by tuning the noise intensity.

  5. Inhibition of nitrogen-fixing activity of the cyanobiont affects the localization of glutamine synthetase in hair cells of Azolla.

    PubMed

    Uheda, Eiji; Maejima, Kazuhiro

    2009-10-15

    In the Azolla-Anabaena association, the host plant Azolla efficiently incorporates and assimilates ammonium ions that are released from the nitrogen-fixing cyanobiont, probably via glutamine synthetase (GS; EC 6.3.1.2) in hair cells, which are specialized cells protruding into the leaf cavity. In order to clarify the regulatory mechanism underlying ammonium assimilation in the Azolla-Anabaena association, Azolla plants were grown under an argon environment (Ar), in which the nitrogen-fixing activity of the cyanobiont was inhibited specifically and completely. The localization of GS in hair cells was determined by immunoelectron microscopy and quantitative analysis of immunogold labeling. Azolla plants grew healthily under Ar when nitrogen sources, such as NO(3)(-) and NH(4)(+), were provided in the growth medium. Both the number of cyanobacterial cells per leaf and the heterocyst frequency of the plants under Ar were similar to those of plants in a nitrogen environment (N(2)). In hair cells of plants grown under Ar, regardless of the type of nitrogen source provided, only weak labeling of GS was observed in the cytoplasm and in chloroplasts. In contrast, in hair cells of plants grown under N(2), abundant labeling of GS was observed in both sites. These findings indicate that specific inhibition of the nitrogen-fixing activity of the cyanobiont affects the localization of GS isoenzymes. Ammonium fixed and released by the cyanobiont could stimulate GS synthesis in hair cells. Simultaneously, the abundant GS, probably GS1, in these cells, could assimilate ammonium rapidly. PMID:19464754

  6. CCN2 modulates hair follicle cycling in mice

    PubMed Central

    Liu, Shangxi; Leask, Andrew

    2013-01-01

    It is critical to understand how stem cell activity is regulated during regeneration. Hair follicles constitute an important model for organ regeneration because, throughout adult life, they undergo cyclical regeneration. Hair follicle stem cells—epithelial cells located in the follicle bulge—are activated by periodic β-catenin activity, which is regulated not only by epithelial-derived Wnt, but also, through as-yet-undefined mechanisms, the surrounding dermal microenvironment. The matricellular protein connective tissue growth factor (CCN2) is secreted into the microenvironment and acts as a multifunctional signaling modifier. In adult skin, CCN2 is largely absent but is unexpectedly restricted to the dermal papillae and outer root sheath. Deletion of CCN2 in dermal papillae and the outer root sheath results in a shortened telogen-phase length and elevated number of hair follicles. Recombinant CCN2 causes decreased β-catenin stability in keratinocytes. In vivo, loss of CCN2 results in elevated numbers of K15-positive epidermal stem cells that possess elevated β-catenin levels and β-catenin–dependent reporter gene expression. These results indicate that CCN2 expression by dermal papillae cells is a physiologically relevant suppressor of hair follicle formation by destabilization of β-catenin and suggest that CCN2 normally acts to maintain stem cell quiescence. PMID:24152728

  7. A case of atypical progressive outer retinal necrosis after highly active antiretroviral therapy.

    PubMed

    Woo, Se Joon; Yu, Hyeong Gon; Chung, Hum

    2004-06-01

    This is a report of an atypical case of progressive outer retinal necrosis (PORN) and the effect of highly active antiretroviral therapy (HAART) on the clinical course of viral retinitis in an acquired immunodeficiency syndrome (AIDS) patient. A 22-year-old male patient infected with human immunodeficiency virus (HIV) presented with unilaterally reduced visual acuity and a dense cataract. After cataract extraction, retinal lesions involving the peripheral and macular areas were found with perivascular sparing and the mud-cracked, characteristic appearance of PORN. He was diagnosed as having PORN based on clinical features and was given combined antiviral treatment. With concurrent HAART, the retinal lesions regressed, with the regression being accelerated by further treatment with intravenous acyclovir and ganciclovir. This case suggests that HAART may change the clinical course of PORN in AIDS patients by improving host immunity. PORN should be included in the differential diagnosis of acute unilateral cataract in AIDS patients. PMID:15255240

  8. Hair dyes resorcinol and lawsone reduce production of melanin in melanoma cells by tyrosinase activity inhibition and decreasing tyrosinase and microphthalmia-associated transcription factor (MITF) expression.

    PubMed

    Lee, Shu-Mei; Chen, Yi-Shyan; Lin, Chih-Chien; Chen, Kuan-Hung

    2015-01-01

    Hair coloring products are one of the most important cosmetics for modern people; there are three major types of hair dyes, including the temporary, semi-permanent and permanent hair dyes. The selected hair dyes (such as ammonium persulfate, sodium persulfate, resorcinol and lawsone) are the important components for hair coloring products. Therefore, we analyzed the effects of these compounds on melanogenesis in B16-F10 melanoma cells. The results proved that hair dyes resorcinol and lawsone can reduce the production of melanin. The results also confirmed that resorcinol and lawsone inhibit mushroom and cellular tyrosinase activities in vitro. Resorcinol and lawsone can also downregulate the protein levels of tyrosinase and microphthalmia-associated transcription factor (MITF) in B16-F10 cells. Thus, we suggest that frequent use of hair dyes may have the risk of reducing natural melanin production in hair follicles. Moreover, resorcinol and lawsone may also be used as hypopigmenting agents to food, agricultural and cosmetic industry in the future. PMID:25584612

  9. Hair Dyes Resorcinol and Lawsone Reduce Production of Melanin in Melanoma Cells by Tyrosinase Activity Inhibition and Decreasing Tyrosinase and Microphthalmia-Associated Transcription Factor (MITF) Expression

    PubMed Central

    Lee, Shu-Mei; Chen, Yi-Shyan; Lin, Chih-Chien; Chen, Kuan-Hung

    2015-01-01

    Hair coloring products are one of the most important cosmetics for modern people; there are three major types of hair dyes, including the temporary, semi-permanent and permanent hair dyes. The selected hair dyes (such as ammonium persulfate, sodium persulfate, resorcinol and lawsone) are the important components for hair coloring products. Therefore, we analyzed the effects of these compounds on melanogenesis in B16-F10 melanoma cells. The results proved that hair dyes resorcinol and lawsone can reduce the production of melanin. The results also confirmed that resorcinol and lawsone inhibit mushroom and cellular tyrosinase activities in vitro. Resorcinol and lawsone can also downregulate the protein levels of tyrosinase and microphthalmia-associated transcription factor (MITF) in B16-F10 cells. Thus, we suggest that frequent use of hair dyes may have the risk of reducing natural melanin production in hair follicles. Moreover, resorcinol and lawsone may also be used as hypopigmenting agents to food, agricultural and cosmetic industry in the future. PMID:25584612

  10. MicroRNA-214 controls skin and hair follicle development by modulating the activity of the Wnt pathway.

    PubMed

    Ahmed, Mohammed I; Alam, Majid; Emelianov, Vladimir U; Poterlowicz, Krzysztof; Patel, Ankit; Sharov, Andrey A; Mardaryev, Andrei N; Botchkareva, Natalia V

    2014-11-24

    Skin development is governed by complex programs of gene activation and silencing, including microRNA-dependent modulation of gene expression. Here, we show that miR-214 regulates skin morphogenesis and hair follicle (HF) cycling by targeting β-catenin, a key component of the Wnt signaling pathway. miR-214 exhibits differential expression patterns in the skin epithelium, and its inducible overexpression in keratinocytes inhibited proliferation, which resulted in formation of fewer HFs with decreased hair bulb size and thinner hair production. The inhibitory effects of miR-214 on HF development and cycling were associated with altered activities of multiple signaling pathways, including decreased expression of key Wnt signaling mediators β-catenin and Lef-1, and were rescued by treatment with pharmacological Wnt activators. Finally, we identify β-catenin as one of the conserved miR-214 targets in keratinocytes. These data provide an important foundation for further analyses of miR-214 as a key regulator of Wnt pathway activity and stem cell functions during normal tissue homeostasis, regeneration, and aging. PMID:25422376

  11. No Correlates for Somatic Motility in Freeze-Fractured Hair-Cell Membranes of Lizards and Birds

    NASA Astrophysics Data System (ADS)

    Köppl, C.; Forge, A.; Manley, G. A.

    2003-02-01

    It is not known whether active processes in mammals and non-mammals are due to the same underlying mechanism. To address this, we studied the size and density of particles in hair-cell membranes in mammals, in a lizard, the Tokay gecko, and in a bird, the barn owl. We surmised that if the prominent particles described in mammalian outer-hair-cell membranes are responsible for cochlear motility, a similar occurrence in non-mammalian hair cells would argue for similar mechanisms. Particle densities differed, however, substantially from those of mammals, suggesting that non-mammals have no membrane-based motility.

  12. Root Hairs

    PubMed Central

    Grierson, Claire; Nielsen, Erik; Ketelaarc, Tijs; Schiefelbein, John

    2014-01-01

    Roots hairs are cylindrical extensions of root epidermal cells that are important for acquisition of nutrients, microbe interactions, and plant anchorage. The molecular mechanisms involved in the specification, differentiation, and physiology of root hairs in Arabidopsis are reviewed here. Root hair specification in Arabidopsis is determined by position-dependent signaling and molecular feedback loops causing differential accumulation of a WD-bHLH-Myb transcriptional complex. The initiation of root hairs is dependent on the RHD6 bHLH gene family and auxin to define the site of outgrowth. Root hair elongation relies on polarized cell expansion at the growing tip, which involves multiple integrated processes including cell secretion, endomembrane trafficking, cytoskeletal organization, and cell wall modifications. The study of root hair biology in Arabidopsis has provided a model cell type for insights into many aspects of plant development and cell biology. PMID:24982600

  13. Enzyme Design From the Bottom Up: An Active Nickel Electrocatalyst with a Structured Peptide Outer Coordination Sphere

    SciTech Connect

    Reback, Matthew L.; Buchko, Garry W.; Kier, Brandon L.; Ginovska-Pangovska, Bojana; Xiong, Yijia; Lense, Sheri; Hou, Jianbo; Roberts, John A.; Sorensen, Christina M.; Raugei, Simone; Squier, Thomas C.; Shaw, Wendy J.

    2014-02-03

    Functional, peptide-containing metal complexes with a well-defined peptide structure have the potential to enhance molecular catalysts via an enzyme-like outer coordination sphere. Here, we report the synthesis and characterization of an active, peptide-based metal complex built upon the well characterized hydrogen production catalyst, Ni(PPh2NPh)2. The incorporated peptide maintains its B-hairpin structure when appended to the metal core, and the electrocatalytic activity of the peptide-based metal complex (~100,000 s-1) is fully retained. The combination of an active molecular catalyst with a structured peptide outer coordination sphere provides a scaffold that permits the incorporation of features of an enzyme-like outer-coordination sphere necessary to create molecular electrocatalysts with en-hanced functionality.

  14. Hair cortisol levels track phylogenetic and age related differences in hypothalamic-pituitary-adrenal (HPA) axis activity in non-human primates.

    PubMed

    Fourie, Nicolaas H; Bernstein, Robin M

    2011-11-01

    Hair has been shown to archive a uniquely time averaged signal of endocrine activity, and holds attractive advantages for both laboratory and field research. Prior research has explored the potential of hair hormone analysis to examine hormone-behavior relationships. To date, no research has focused on the potential of the technique to investigate age-related changes or taxon differences in endocrine function. It is known that non-human primate infants of many taxa exhibit high cortisol levels after parturition, which rapidly decline with age. It has also been shown that hypercortisolism generally characterizes platyrrhine (New World monkey) endocrine function. These endocrine trends have been characterized using cortisol levels determined from serum, plasma, and feces. Here we test whether cortisol levels determined from hair recover similar phylogenetic and age related patterns in endocrine function in non-human primates. In order to test whether hair cortisol reflect infant hypercortisolism with significant age-related decline, hair cortisol levels are measured in samples from wild vervet monkeys (Chlorocebus aethiops) and captive Guinea baboons (Papio hamadryas papio), ranging in age from infants through juveniles. Further, in order to test whether platyrrhines exhibit significantly higher hair cortisol levels compared to strepsirrhines and catarrhines, and therefore faithfully recover similar signals as more traditionally used substrates (e.g. serum), hair cortisol levels are quantified in adult female hair samples collected from a broad range of non-human primate taxa. Results confirm that hair cortisol levels accurately reflect known phylogenetic and age related patterns of circulating cortisol levels. Therefore, these results suggest that hair may be an ideal hormone bearing substrate for research focused on the examination of population endocrine profiles, cross-sectional studies of endocrine function and taxon variation in hormone levels, as well as

  15. Bacterial Outer Membrane Vesicles Mediate Cytosolic Localization of LPS and Caspase-11 Activation.

    PubMed

    Vanaja, Sivapriya Kailasan; Russo, Ashley J; Behl, Bharat; Banerjee, Ishita; Yankova, Maya; Deshmukh, Sachin D; Rathinam, Vijay A K

    2016-05-19

    Sensing of lipopolysaccharide (LPS) in the cytosol triggers caspase-11 activation and is central to host defense against Gram-negative bacterial infections and to the pathogenesis of sepsis. Most Gram-negative bacteria that activate caspase-11, however, are not cytosolic, and the mechanism by which LPS from these bacteria gains access to caspase-11 in the cytosol remains elusive. Here, we identify outer membrane vesicles (OMVs) produced by Gram-negative bacteria as a vehicle that delivers LPS into the cytosol triggering caspase-11-dependent effector responses in vitro and in vivo. OMVs are internalized via endocytosis, and LPS is released into the cytosol from early endosomes. The use of hypovesiculating bacterial mutants, compromised in their ability to generate OMVs, reveals the importance of OMVs in mediating the cytosolic localization of LPS. Collectively, these findings demonstrate a critical role for OMVs in enabling the cytosolic entry of LPS and, consequently, caspase-11 activation during Gram-negative bacterial infections. PMID:27156449

  16. [Hair colorants].

    PubMed

    Urbanek-Karłowska, B; Luks, E; Jedra, M; Kiss, E; Malanowska, M

    1997-01-01

    The properties, mode of action and its duration of the preparations used for hair dyeing are described, together with their chemical components, and also preparations of herbal origin. The chemical reactions are described in detail which lead the development of a color polymer occurring during hair dyeing. The studies are presented which are used for toxicological assessment of the raw materials which are the components of the colorants, and the list is included of hair colorants permitted for use in Poland. PMID:9562811

  17. 76 FR 79705 - Information Collection Activities: Operations in the Outer Continental Shelf for Minerals Other...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-22

    ... the Outer Continental Shelf for Minerals Other than Oil, Gas, and Sulphur; Submitted for Office of..., ``Operations in the Outer Continental Shelf for Minerals Other than Oil, Gas, and Sulphur''. DATES: Submit... Continental Shelf for Minerals other than Oil, Gas, and Sulphur. OMB Control Number: 1014-NEW. Abstract:...

  18. Sulfotransferase activity in plucked hair follicles predicts response to topical minoxidil in the treatment of female androgenetic alopecia.

    PubMed

    Roberts, Janet; Desai, Nisha; McCoy, John; Goren, Andy

    2014-01-01

    Two percent topical minoxidil is the only US Food and Drug Administration-approved drug for the treatment of female androgenetic alopecia (AGA). Its success has been limited by the low percentage of responders. Meta-analysis of several studies reporting the number of responders to 2% minoxidil monotherapy indicates moderate hair regrowth in only 13-20% of female patients. Five percent minoxidil solution, when used off-label, may increase the percentage of responders to as much as 40%. As such, a biomarker for predicting treatment response would have significant clinical utility. In a previous study, Goren et al. reported an association between sulfotransferase activity in plucked hair follicles and minoxidil response in a mixed cohort of male and female patients. The aim of this study was to replicate these findings in a well-defined cohort of female patients with AGA treated with 5% minoxidil daily for a period of 6 months. Consistent with the prior study, we found that sulfotransferase activity in plucked hair follicles predicts treatment response with 93% sensitivity and 83% specificity. Our study further supports the importance of minoxidil sulfation in eliciting a therapeutic response and provides further insight into novel targets for increasing minoxidil efficacy. PMID:24773771

  19. Pharmacologic interventions in aging hair

    PubMed Central

    Trüeb, Ralph M

    2006-01-01

    The appearance of hair plays an important role in people’s overall physical appearance and self-perception. With today’s increasing life-expectations, the desire to look youthful plays a bigger role than ever. The hair care industry has become aware of this and is delivering active products directed towards meeting this consumer demand. The discovery of pharmacological targets and the development of safe and effective drugs also indicate strategies of the drug industry for maintenance of healthy and beautiful hair. Hair aging comprises weathering of the hair shaft, decrease of melanocyte function, and decrease in hair production. The scalp is subject to intrinsic and extrinsic aging. Intrinsic factors are related to individual genetic and epigenetic mechanisms with interindividual variation: prototypes are familial premature graying, and androgenetic alopecia. Currently available pharmacologic treatment modalities with proven efficacy for treatment of androgenetic alopecia are topical minoxidil and oral finasteride. Extrinsic factors include ultraviolet radiation and air pollution. Experimental evidence supports the hypothesis that oxidative stress also plays a role in hair aging. Topical anti-aging compounds include photoprotectors and antioxidants. In the absence of another way to reverse hair graying, hair colorants remain the mainstay of recovering lost hair color. Topical liposome targeting for melanins, genes, and proteins selectively to hair follicles are currently under investigation. PMID:18044109

  20. Pharmacologic interventions in aging hair.

    PubMed

    Trüeb, Ralph M

    2006-01-01

    The appearance of hair plays an important role in people's overall physical appearance and self-perception. With today's increasing life-expectations, the desire to look youthful plays a bigger role than ever. The hair care industry has become aware of this and is delivering active products directed towards meeting this consumer demand. The discovery of pharmacological targets and the development of safe and effective drugs also indicate strategies of the drug industry for maintenance of healthy and beautiful hair. Hair aging comprises weathering of the hair shaft, decrease of melanocyte function, and decrease in hair production. The scalp is subject to intrinsic and extrinsic aging. Intrinsic factors are related to individual genetic and epigenetic mechanisms with interindividual variation: prototypes are familial premature graying, and androgenetic alopecia. Currently available pharmacologic treatment modalities with proven efficacy for treatment of androgenetic alopecia are topical minoxidil and oral finasteride. Extrinsic factors include ultraviolet radiation and air pollution. Experimental evidence supports the hypothesis that oxidative stress also plays a role in hair aging. Topical anti-aging compounds include photoprotectors and antioxidants. In the absence of another way to reverse hair graying, hair colorants remain the mainstay of recovering lost hair color. Topical liposome targeting for melanins, genes, and proteins selectively to hair follicles are currently under investigation. PMID:18044109

  1. A genomic region encompassing a newly identified exon provides enhancing activity sufficient for normal myo7aa expression in zebrafish sensory hair cells.

    PubMed

    Ernest, Sylvain; Rosa, Frédéric M

    2015-09-01

    MYO7A is an unconventional myosin involved in the structural organization of hair bundles at the apex of sensory hair cells (SHCs) where it serves mechanotransduction in the process of hearing and balance. Mutations of MYO7A are responsible for abnormal shaping of hair bundles, resulting in human deafness and murine deafness/circling behavior. Myo7aa, expressed in SHCs of the inner ear and lateral line of zebrafish, causes circling behavior and abnormal hair cell function when deficient in mariner mutant. This work identifies a new hair cell-specific enhancer, highly conserved between species, located within Intron 2-3 of zebrafish myosin 7a (myo7aa) gene. This enhancer is contained within a 761-bp DNA fragment that encompasses a newly identified Exon of myo7aa and whose activity does not depend on orientation. Compensation of mariner mutation by expression of mCherry-Myo7aa fusion protein under the control of this 761-bp DNA fragment results in recovery of balance, normal hair bundle shape and restored hair cell function. Two smaller adjacent fragments (344-bp and 431-bp), extracted from the 761-bp fragment, both show hair cell-specific enhancing activity, with apparently reduced intensity and coverage. These data should help understand the role of Myo7aa in sensory hair cell differentiation and function. They provide tools to decipher how myo7aa gene is expressed and regulated in SHCs by allowing the identification of potential transcription factors involved in this process. The discovered enhancer could represent a new target for the identification of deafness-causing mutations affecting human MYO7A. PMID:25556989

  2. Outer Membrane Vesicles Mediate Transport of Biologically Active Vibrio cholerae Cytolysin (VCC) from V. cholerae Strains

    PubMed Central

    Elluri, Sridhar; Enow, Constance; Vdovikova, Svitlana; Rompikuntal, Pramod K.; Dongre, Mitesh; Carlsson, Sven; Pal, Amit; Uhlin, Bernt Eric; Wai, Sun Nyunt

    2014-01-01

    Background Outer membrane vesicles (OMVs) released from Gram-negative bacteria can serve as vehicles for the translocation of virulence factors. Vibrio cholerae produce OMVs but their putative role in translocation of effectors involved in pathogenesis has not been well elucidated. The V. cholerae cytolysin (VCC), is a pore-forming toxin that lyses target eukaryotic cells by forming transmembrane oligomeric β-barrel channels. It is considered a potent toxin that contributes to V. cholerae pathogenesis. The mechanisms involved in the secretion and delivery of the VCC have not been extensively studied. Methodology/Principal Findings OMVs from V. cholerae strains were isolated and purified using a differential centrifugation procedure and Optiprep centrifugation. The ultrastructure and the contents of OMVs were examined under the electron microscope and by immunoblot analyses respectively. We demonstrated that VCC from V. cholerae strain V:5/04 was secreted in association with OMVs and the release of VCC via OMVs is a common feature among V. cholerae strains. The biological activity of OMV-associated VCC was investigated using contact hemolytic assay and epithelial cell cytotoxicity test. It showed toxic activity on both red blood cells and epithelial cells. Our results indicate that the OMVs architecture might play a role in stability of VCC and thereby can enhance its biological activities in comparison with the free secreted VCC. Furthermore, we tested the role of OMV-associated VCC in host cell autophagy signalling using confocal microscopy and immunoblot analysis. We observed that OMV-associated VCC triggered an autophagy response in the target cell and our findings demonstrated for the first time that autophagy may operate as a cellular defence mechanism against an OMV-associated bacterial virulence factor. Conclusion/Significance Biological assays of OMVs from the V. cholerae strain V:5/04 demonstrated that OMV-associated VCC is indeed biologically active and

  3. Interaural attention modulates outer hair cell function.

    PubMed

    Srinivasan, Sridhar; Keil, Andreas; Stratis, Kyle; Osborne, Aaron F; Cerwonka, Colin; Wong, Jennifer; Rieger, Brenda L; Polcz, Valerie; Smith, David W

    2014-12-01

    Mounting evidence suggests that auditory attention tasks may modulate the sensitivity of the cochlea by way of the corticofugal and the medial olivocochlear (MOC) efferent pathways. Here, we studied the extent to which a separate efferent tract, the 'uncrossed' MOC, which functionally connects the two ears, mediates inter-aural selective attention. We compared distortion product otoacoustic emissions (DPOAEs) in one ear with binaurally presented primaries, using an intermodal target detection task in which participants were instructed to report the occurrence of brief target events (visual changes, tones). Three tasks were compared under identical physical stimulation: (i) report brief tones in the ear in which DPOAE responses were recorded; (ii) report brief tones presented to the contralateral, non-recorded ear; and (iii) report brief phase shifts of a visual grating at fixation. Effects of attention were observed as parallel shifts in overall DPOAE contour level, with DPOAEs relatively higher in overall level when subjects ignored the auditory stimuli and attended to the visual stimulus, compared with both of the auditory-attending conditions. Importantly, DPOAE levels were statistically lowest when attention was directed to the ipsilateral ear in which the DPOAE recordings were made. These data corroborate notions that top-down mechanisms, via the corticofugal and medial efferent pathways, mediate cochlear responses during intermodal attention. New findings show attending to one ear can significantly alter the physiological response of the contralateral, unattended ear, probably through the uncrossed-medial olivocochlear efferent fibers connecting the two ears. PMID:25302959

  4. C1q binding and activation of the complement classical pathway by Klebsiella pneumoniae outer membrane proteins.

    PubMed Central

    Albertí, S; Marqués, G; Camprubí, S; Merino, S; Tomás, J M; Vivanco, F; Benedí, V J

    1993-01-01

    The mechanisms of killing of Klebsiella pneumoniae serum-sensitive strains in nonimmune serum by the complement classical pathway have been studied. The bacterial cell surface components that bind C1q more efficiently were identified as two major outer membrane proteins, presumably the porins of this bacterial species. These two outer membrane proteins were isolated from a representative serum-sensitive strain. We have demonstrated that in their purified form, they bind C1q and activate the classical pathway in an antibody-independent manner, with the subsequent consumption of C4 and reduction of the serum total hemolytic activity. Activation of the classical pathway has been observed in human nonimmune serum and agammaglobulinemic serum (both depleted in factor D). Binding of C1q to other components of the bacterial outer membrane, in particular the rough lipopolysaccharide, could not be demonstrated. Activation of the classical pathway by this lipopolysaccharide was also much less efficient than activation by the two outer membrane proteins. The antibody-independent binding of C1q to serum-sensitive strains was independent of the presence of capsular polysaccharide, while strains possessing lipopolysaccharide O antigen bind less C1q and are resistant to complement-mediated killing. Images PMID:8432605

  5. Axin2 marks quiescent hair follicle bulge stem cells that are maintained by autocrine Wnt/β-catenin signaling

    PubMed Central

    Lim, Xinhong; Tan, Si Hui; Yu, Ka Lou; Lim, Sophia Beng Hui; Nusse, Roeland

    2016-01-01

    How stem cells maintain their identity and potency as tissues change during growth is not well understood. In mammalian hair, it is unclear how hair follicle stem cells can enter an extended period of quiescence during the resting phase but retain stem cell potential and be subsequently activated for growth. Here, we use lineage tracing and gene expression mapping to show that the Wnt target gene Axin2 is constantly expressed throughout the hair cycle quiescent phase in outer bulge stem cells that produce their own Wnt signals. Ablating Wnt signaling in the bulge cells causes them to lose their stem cell potency to contribute to hair growth and undergo premature differentiation instead. Bulge cells express secreted Wnt inhibitors, including Dickkopf (Dkk) and secreted frizzled-related protein 1 (Sfrp1). However, the Dickkopf 3 (Dkk3) protein becomes localized to the Wnt-inactive inner bulge that contains differentiated cells. We find that Axin2 expression remains confined to the outer bulge, whereas Dkk3 continues to be localized to the inner bulge during the hair cycle growth phase. Our data suggest that autocrine Wnt signaling in the outer bulge maintains stem cell potency throughout hair cycle quiescence and growth, whereas paracrine Wnt inhibition of inner bulge cells reinforces differentiation. PMID:26903625

  6. Axin2 marks quiescent hair follicle bulge stem cells that are maintained by autocrine Wnt/β-catenin signaling.

    PubMed

    Lim, Xinhong; Tan, Si Hui; Yu, Ka Lou; Lim, Sophia Beng Hui; Nusse, Roeland

    2016-03-15

    How stem cells maintain their identity and potency as tissues change during growth is not well understood. In mammalian hair, it is unclear how hair follicle stem cells can enter an extended period of quiescence during the resting phase but retain stem cell potential and be subsequently activated for growth. Here, we use lineage tracing and gene expression mapping to show that the Wnt target gene Axin2 is constantly expressed throughout the hair cycle quiescent phase in outer bulge stem cells that produce their own Wnt signals. Ablating Wnt signaling in the bulge cells causes them to lose their stem cell potency to contribute to hair growth and undergo premature differentiation instead. Bulge cells express secreted Wnt inhibitors, including Dickkopf (Dkk) and secreted frizzled-related protein 1 (Sfrp1). However, the Dickkopf 3 (Dkk3) protein becomes localized to the Wnt-inactive inner bulge that contains differentiated cells. We find that Axin2 expression remains confined to the outer bulge, whereas Dkk3 continues to be localized to the inner bulge during the hair cycle growth phase. Our data suggest that autocrine Wnt signaling in the outer bulge maintains stem cell potency throughout hair cycle quiescence and growth, whereas paracrine Wnt inhibition of inner bulge cells reinforces differentiation. PMID:26903625

  7. Wnt activation protects against neomycin-induced hair cell damage in the mouse cochlea.

    PubMed

    Liu, L; Chen, Y; Qi, J; Zhang, Y; He, Y; Ni, W; Li, W; Zhang, S; Sun, S; Taketo, M M; Wang, L; Chai, R; Li, H

    2016-01-01

    Recent studies have reported the role of Wnt/β-catenin signaling in hair cell (HC) development, regeneration, and differentiation in the mouse cochlea; however, the role of Wnt/β-catenin signaling in HC protection remains unknown. In this study, we took advantage of transgenic mice to specifically knockout or overactivate the canonical Wnt signaling mediator β-catenin in HCs, which allowed us to investigate the role of Wnt/β-catenin signaling in protecting HCs against neomycin-induced damage. We first showed that loss of β-catenin in HCs made them more vulnerable to neomycin-induced injury, while constitutive activation of β-catenin in HCs reduced HC loss both in vivo and in vitro. We then showed that loss of β-catenin in HCs increased caspase-mediated apoptosis induced by neomycin injury, while β-catenin overexpression inhibited caspase-mediated apoptosis. Finally, we demonstrated that loss of β-catenin in HCs led to increased expression of forkhead box O3 transcription factor (Foxo3) and Bim along with decreased expression of antioxidant enzymes; thus, there were increased levels of reactive oxygen species (ROS) after neomycin treatment that might be responsible for the increased aminoglycoside sensitivity of HCs. In contrast, β-catenin overexpression reduced Foxo3 and Bim expression and ROS levels, suggesting that β-catenin is protective against neomycin-induced HC loss. Our findings demonstrate that Wnt/β-catenin signaling has an important role in protecting HCs against neomycin-induced HC loss and thus might be a new therapeutic target for the prevention of HC death. PMID:26962686

  8. Wnt activation protects against neomycin-induced hair cell damage in the mouse cochlea

    PubMed Central

    Liu, L; Chen, Y; Qi, J; Zhang, Y; He, Y; Ni, W; Li, W; Zhang, S; Sun, S; Taketo, M M; Wang, L; Chai, R; Li, H

    2016-01-01

    Recent studies have reported the role of Wnt/β-catenin signaling in hair cell (HC) development, regeneration, and differentiation in the mouse cochlea; however, the role of Wnt/β-catenin signaling in HC protection remains unknown. In this study, we took advantage of transgenic mice to specifically knockout or overactivate the canonical Wnt signaling mediator β-catenin in HCs, which allowed us to investigate the role of Wnt/β-catenin signaling in protecting HCs against neomycin-induced damage. We first showed that loss of β-catenin in HCs made them more vulnerable to neomycin-induced injury, while constitutive activation of β-catenin in HCs reduced HC loss both in vivo and in vitro. We then showed that loss of β-catenin in HCs increased caspase-mediated apoptosis induced by neomycin injury, while β-catenin overexpression inhibited caspase-mediated apoptosis. Finally, we demonstrated that loss of β-catenin in HCs led to increased expression of forkhead box O3 transcription factor (Foxo3) and Bim along with decreased expression of antioxidant enzymes; thus, there were increased levels of reactive oxygen species (ROS) after neomycin treatment that might be responsible for the increased aminoglycoside sensitivity of HCs. In contrast, β-catenin overexpression reduced Foxo3 and Bim expression and ROS levels, suggesting that β-catenin is protective against neomycin-induced HC loss. Our findings demonstrate that Wnt/β-catenin signaling has an important role in protecting HCs against neomycin-induced HC loss and thus might be a new therapeutic target for the prevention of HC death. PMID:26962686

  9. Perinuclear Localization of Internalized Outer Membrane Vesicles Carrying Active Cytolethal Distending Toxin from Aggregatibacter actinomycetemcomitans

    PubMed Central

    Rompikuntal, Pramod Kumar; Thay, Bernard; Khan, Muhammad Khanzeb; Alanko, Jonna; Penttinen, Anna-Maija; Asikainen, Sirkka; Wai, Sun Nyunt

    2012-01-01

    Aggregatibacter actinomycetemcomitans is implicated in aggressive forms of periodontitis. Similarly to several other Gram-negative species, this organism produces and excretes a cytolethal distending toxin (CDT), a genotoxin associated with cell distention, G2 cell cycle arrest, and/or apoptosis in many mammalian cell types. In this study, we have identified A. actinomycetemcomitans outer membrane vesicles (OMVs) as a vehicle for simultaneous delivery of multiple proteins, including CDT, into human cells. The OMV proteins were internalized in both HeLa cells and human gingival fibroblasts (HGF) via a mechanism of OMV fusion with lipid rafts in the plasma membrane. The active toxin unit, CdtB, was localized inside the nucleus of the intoxicated cells, whereas OmpA and proteins detected using an antibody specific to whole A. actinomycetemcomitans serotype a cells had a perinuclear distribution. In accordance with a tight association of CdtB with OMVs, vesicles isolated from A. actinomycetemcomitans strain D7SS (serotype a), in contrast to OMVs from a D7SS cdtABC mutant, induced a cytolethal distending effect on HeLa and HGF cells, indicating that OMV-associated CDT was biologically active. Association of CDT with OMVs was also observed in A. actinomycetemcomitans isolates belonging to serotypes b and c, indicating that OMV-mediated release of CDT may be conserved in A. actinomycetemcomitans. Although the role of A. actinomycetemcomitans OMVs in periodontal disease has not yet been elucidated, our present data suggest that OMVs could deliver biologically active CDT and additional virulence factors into susceptible cells of the periodontium. PMID:22025516

  10. The active outer shell of Earth: What remains to be explored in carbon and life interactions?

    NASA Astrophysics Data System (ADS)

    Boetius, Antje

    2016-04-01

    Recent advances in methods and technologies have allowed us to explore the interaction between life and abiotic resources from nano to megascales in space and time, and this has set new challenges to the geosciences. This lecture aims at discussing key biological factors in the question of the dynamics of carbon reservoirs and fluxes on Earth, and the challenges to the geosciences to incorporate and further this knowledge. Humans themselves as one such biological factor have considerably changed the dynamics of carbon and other elements, with repercussions to most other life forms on Earth. Which other life forms shape carbon fluxes and reservoirs, and what do we know about their key traits in catalyzing geochemical reactions, their past and their future? I will use case studies from my own research field - geobiology of the oceans and the cryosphere - and from other geoscience areas to highlight the considerable non-linearity introduced by life to element fluxes and the environment; and discuss advances but also gaps in knowledge and research approaches concerning assessing and predicting carbon transformations in the active outer shell of Earth.

  11. Active Hydrogenation Catalyst with a Structured, Peptide-Based Outer-Coordination Sphere

    SciTech Connect

    Jain, Avijita; Buchko, Garry W.; Reback, Matthew L.; O'Hagan, Molly J.; Ginovska-Pangovska, Bojana; Linehan, John C.; Shaw, Wendy J.

    2012-10-05

    The synthesis, catalytic activity, and structural features of a rhodium-based hydrogenation catalyst containing a phosphine ligand coupled to a 14-residue peptide are reported. Both CD and NMR spectroscopy show that the peptide adopts a helical structure in 1:1:1 TFE/MeCN/H2O that is maintained when the peptide is attached to the ligand and when the ligand is attached to the metal complex. The metal complex hydrogenates aqueous solutions of 3-butenol to 1-butanol at 360 ± 50 turnovers/Rh/h at 294 K. This peptide- based catalyst represents a starting point for developing and characterizing a peptide-based outer-coordination sphere that can be used to introduce enzyme-like features into molecular catalysts. This work was funded by the US DOE Basic Energy Sciences, Chemical Sciences, Geoscience and Biosciences Division (AJ, JCL and WJS), the Office of Science Early Career Research Program through the Office of Basic Energy Sciences (GWB, MLR and WJS). Part of the research was conducted at the W.R. Wiley Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by U.S. Department of Energy’s Office of Biolog-ical and Environmental Research (BER) program located at Pacific Northwest National Laboratory (PNNL). PNNL is operated by Battelle for the U.S. Department of Energy.

  12. Ingrowing Hair

    PubMed Central

    Luo, Di-Qing; Liang, Yu-Hua; Li, Xi-Qing; Zhao, Yu-Kun; Wang, Fang; Sarkar, Rashmi

    2016-01-01

    Abstract Cutaneous pili migrans and creeping eruption caused by parasitic diseases may present as a moving linear lesion in skin. The former, caused by a hair shaft or fragment embedded in the superficial skin or middle dermis, is a rare condition characterized by creeping eruption with a black line observed at the advancing end. In exceptionally rare instance, the hair grows inside the skin and burrows in the uppermost dermis, such a condition has been called “ingrown hair.” We report a 30-year-old Chinese man, who was accustomed to pull or extrude the beard hairs, with 1-year history of slowly extending black linear eruption on his right chin. Cutaneous examination revealed a 4-cm long black linear lesion beneath the skin associated with edematous erythema around and folliculitis on both ends of the lesion. After treatment with topical mupirocin ointment, the erythema and folliculitis improved and 2 hairs of the beard with hair follicles were pulled out from the skin. Two weeks later, another similar black line about 1 cm in length in the skin presented on the prior lesional area, which was pulled out by a shallow incision of the skin and was also demonstrated as a beard hair with hair follicle. The patient was diagnosed as “ingrowing hair” with multiple recurrences. The lesions recovered after the beard hairs were pulled out. No recurrence occurred in a year of follow-up. We suggest that “ingrowing hair” is better than “ingrown hair” to describe such a condition. Pulling out the involved hair and correcting the bad practice are its optimal management strategies. PMID:27175694

  13. Detection of mercury in the 411-year-old beard hairs of the astronomer Tycho Brahe by elemental analysis in electron microscopy.

    PubMed

    Jonas, Ludwig; Jaksch, Heiner; Zellmann, Erhard; Klemm, Kerstin I; Andersen, Peter Hvilshøj

    2012-10-01

    Hairs more than 400 years old of the famous astronomer Tycho Brahe were studied by electron microscopy to evaluate the hypothesis that Johannes Kepler murdered his teacher Brahe by mercury intoxication. The beard hairs showed a well-preserved ultrastructure with typical hair scales and melanosomes. The authors detected an accumulation of electron-dense granules of about 10 nm inside the outer hair scales, but not in the hair shaft and roots. At the places of these heavy-metal-containing granules they detected mercury besides other elements by energy dispersive X-ray analysis (EDX, Oxford, UK) in a field cathode scanning electron microscope (SEM, Gemini, Zeiss). The mercury-containing granules were found over the whole length of hairs, but only in the outer hair scales. Nevertheless, surface coatings of hairs were free of mercury. This distribution of mercury does not support the murder hypothesis, but could be related to precipitation of mercury dust from the air during long-term alchemistic activities. PMID:23025649

  14. Eya1-Six1 interaction is sufficient to induce hair cell fate in the cochlea by activating Atoh1 expression in cooperation with Sox2

    PubMed Central

    Ahmed, Mohi; Wong, Elaine Y-M.; Sun, Jianbo; Xu, Jinshu; Wang, Feng; Xu, Pin-Xian

    2012-01-01

    SUMMARY Inner ear hair cell differentiation requires Atoh1 function, while Eya1, Six1 and Sox2 are coexpressed in sensory progenitors and mutations in these genes cause sensorineural hearing loss. However, how these genes are linked functionally and the transcriptional networks controlling hair cell induction remain unclear. Here, we show that Eya1/Six1 are necessary for hair cell development and their coexpression in mouse cochlear explants is sufficient to induce hair cell fate in the nonsensory epithelium expressing low level Sox2 by activating not only Atoh1-dependent but also -independent pathways and that both pathways induce Pou4f3 to promote hair cell differentiation. Sox2 cooperates with Eya1/Six1 to synergistically activate Atoh1 transcription via direct binding to the conserved Sox- and Six-binding sites in Atoh1 enhancers and these proteins physically interact. Our findings demonstrate that direct and cooperative interactions between the Sox2, Six1 and Eya1 proteins coordinate Atoh1 expression to specify hair cell fate. PMID:22340499

  15. An ABC transporter and an outer membrane lipoprotein participate in posttranslational activation of type VI secretion in Pseudomonas aeruginosa.

    PubMed

    Casabona, Maria G; Silverman, Julie M; Sall, Khady M; Boyer, Frédéric; Couté, Yohann; Poirel, Jessica; Grunwald, Didier; Mougous, Joseph D; Elsen, Sylvie; Attree, Ina

    2013-02-01

    Pseudomonas aeruginosa is capable of injecting protein toxins into other bacterial cells through one of its three type VI secretion systems (T6SSs). The activity of this T6SS is tightly regulated on the posttranslational level by phosphorylation-dependent and -independent pathways. The phosphorylation-dependent pathway consists of a Threonine kinase/phosphatase pair (PpkA/PppA) that acts on a forkhead domain-containing protein, Fha1, and a periplasmic protein, TagR, that positively regulates PpkA. In the present work, we biochemically and functionally characterize three additional proteins of the phosphorylation-dependent regulatory cascade that controls T6S activation: TagT, TagS and TagQ. We show that similar to TagR, these proteins act upstream of the PpkA/PppA checkpoint and influence phosphorylation of Fha1 and, apparatus assembly and effector export. Localization studies demonstrate that TagQ is an outer membrane lipoprotein and TagR is associated with the outer membrane. Consistent with their homology to lipoprotein outer membrane localization (Lol) components, TagT and TagS form a stable inner membrane complex with ATPase activity. However, we find that outer membrane association of T6SS lipoproteins TagQ and TssJ1, and TagR, is unaltered in a ΔtagTS background. Notably, we found that TagQ is indispensible for anchoring of TagR to the outer membrane fraction. As T6S-dependent fitness of P. aeruginosa requires TagT, S, R and Q, we conclude that these proteins likely participate in a trans-membrane signalling pathway that promotes H1-T6SS activity under optimal environmental conditions. PMID:22765374

  16. Arctic summary report: Outer Continental Shelf oil and gas activities in the Arctic and their onshore impacts

    NASA Astrophysics Data System (ADS)

    Lynch, C.; Slitor, D. L.; Rudolph, R. W.

    1985-01-01

    Issues and developments occuring in the Arctic Outer Continental Shelf subregion are discussed. The geology and hydrocarbon potential of the Diapir Field petroleum provinces are detailed. Recent lease sales, exploration activities, and the first development proposals for offshore areas of the North slope are considered. Issues relating to transporting resources from production islands to shore and various proposals for moving Arctic hydrocarbons to market are presented. Production projects onshore and possible support bases for offshore activity are also examined.

  17. Hair growth in neonatally undernourished rats.

    PubMed

    Salas, M; Pulido, S; Torrero, C; Regalado, M; Loranca, A

    1995-01-01

    Interaction between neonatal undernutrition and the increased self-grooming activity upon hair growth of several body areas was analyzed in rats of 10, 20 and 30 days of age. Light microscopic observations on methylene blue impregnated hairs showed that these perinatal influences delayed the growth of hair follicles and thickness and length of hair measurements of the head and thoracic areas. The hair growth of lateral abdominal regions was less affected. Data suggest that hair alterations are primarily related to food deprivation since hair follicle measures of all skin areas were more affected than the distal hair measurements. Moreover, the distribution of impaired hair growth on different body areas correlates well with the increased self-grooming components associated to neonatal undernourishment. PMID:8914627

  18. Hair Loss

    MedlinePlus

    ... En Español Making a Change – Your Personal Plan Hot Topics Meningitis Choosing Your Mood Prescription Drug Abuse ... much heat on your hair (like using a hot iron or hot blow drying). Another type of ...

  19. Dry hair

    MedlinePlus

    ... or using harsh soaps or alcohols Excessive blow-drying Dry air Menkes kinky hair syndrome Malnutrition Underactive ... or twice a week Add conditioners Avoid blow drying and harsh styling products

  20. Hair Loss

    MedlinePlus

    ... problems, diabetes, or lupus. If you take certain medicines or have chemotherapy for cancer, you may also ... cause will correct the problem. Other treatments include medicines and hair restoration.

  1. Nutrition and hair: deficiencies and supplements.

    PubMed

    Finner, Andreas M

    2013-01-01

    Hair follicle cells have a high turnover. A caloric deprivation or deficiency of several components, such as proteins, minerals, essential fatty acids, and vitamins, caused by inborn errors or reduced uptake, can lead to structural abnormalities, pigmentation changes, or hair loss, although exact data are often lacking. The diagnosis is established through a careful history, clinical examination of hair loss activity, and hair quality and confirmed through targeted laboratory tests. Examples of genetic hair disorders caused by reduced nutritional components are zinc deficiency in acrodermatitis enteropathica and copper deficiency in Menkes kinky hair syndrome. PMID:23159185

  2. Plasminogen activator/coagulase gene of Yersinia pestis is responsible for degradation of plasmid-encoded outer membrane proteins.

    PubMed Central

    Sodeinde, O A; Sample, A K; Brubaker, R R; Goguen, J D

    1988-01-01

    The related family of virulence plasmids found in the three major pathogens of the genus Yersinia all have the ability to encode a set of outer membrane proteins. In Y. enterocolitica and Y. pseudotuberculosis, these proteins are major constituents of the outer membrane when their synthesis is fully induced. In contrast, they have been difficult to detect in Y. pestis. It has recently been established that Y. pestis does synthesize these proteins, but that they are rapidly degraded due to some activity determined by the 9.5-kilobase plasmid commonly found in Y. pestis strains. We show that mutations in the pla gene of this plasmid, which encodes both the plasminogen activator and coagulase activities, blocked this degradation. A cloned 1.4-kilobase DNA fragment carrying pla was also sufficient to cause degradation in the absence of the 9.5-kilobase plasmid. Images PMID:2843471

  3. Proteomics demonstration that histone H4 is a colchicine-induced retro-modulator of growth and alkaline phosphatase activity in hair follicle dermal papilla culture.

    PubMed

    Hsia, Ching-Wu; Shui, Hao-Ai; Wang, Chih-Yuan; Yu, Hui-Ming; Ho, Ming-Yi; Cheng, Kur-Ta; Tseng, Min-Jen

    2011-05-16

    Dermal papilla cells (DPCs) control the development of hair follicles via cell-cell interactions and extracellular molecules. Colchicine affected active anagen DPCs to result in hair loss in the clinical setting. The purpose of this study was to identify the retro-modulator released by DPCs exposed to sub-toxic dose of colchicine and elucidate its effect on dermal papilla culture. The molecular-weight cutoff ultrafiltration and HPLC were used to purify the components of colchicine-treated DPC secretomes and examined their ability to down-regulate the growth and alkaline phosphatase (ALP) activity of DPCs. The active product was identified by in-gel trypsin digestion, nano-LC-ESI-MS/MS and validated by Western blot to be histone H4 (P62804), which inhibited the proliferation and diminished the ALP activity of cultured DPCs. Treating DPCs with recombinant histone H4 reproduced the growth inhibition effect whereas adding antibody to immunoneutralize histone H4 abolished this growth inhibitory consequence. DPCs with high ALP activity can induce the neogenesis of hair follicles and support the hair fiber growth in vivo. Our results indicated that sub-lethal colchicine can inactivate DPCs through releasing histone H4. Through the investigation of the retro-modulation of histone H4 on dermal papillae may give implications for understanding the mechanism of colchicine-induced hair disorder. PMID:21362507

  4. Hair growth-promotion effects of different alternating current parameter settings are mediated by the activation of Wnt/β-catenin and MAPK pathway.

    PubMed

    Sohn, Ki Min; Jeong, Kwan Ho; Kim, Jung Eun; Park, Young Min; Kang, Hoon

    2015-12-01

    Electrical stimulation is being used in variable skin therapeutic conditions. There have been clinical studies demonstrating the positive effect of electrical stimuli on hair regrowth. However, the underlying exact mechanism and optimal parameter settings are not clarified yet. To investigate the effects of different parameter settings of electrical stimuli on hair growth by examining changes in human dermal papilla cells (hDPCs) in vitro and by observing molecular changes in animal tissue. In vitro, cultured hDPCs were electrically stimulated with different parameter settings at alternating current (AC). Cell proliferation was measured by MTT assay. The Ki67 expression was measured by immunofluorescence. Hair growth-related gene expressions were measured by RT-PCR. In animal model, different parameter settings of AC were applied to the shaved dorsal skin of rabbit for 8 weeks. Expression of hair-related genes in the skin of rabbit was examined by RT-PCR. At low voltage power (3.5 V) and low frequency (1 or 2 MHz) with AC, in vitro proliferation of hDPCs was successfully induced. A significant increase in Wnt/β-catenin, Ki67, p-ERK and p-AKT expressions was observed under the aforementioned settings. In animal model, hair regrowth was observed in the entire stimulated areas under individual conditions. Expression of hair-related genes in the skin significantly increased on the 6th week of treatment. There are optimal conditions for electrical stimulated hair growth, and they might be different in the cells, animals and human tissues. Electrical stimuli induce mechanisms such as the activation of Wnt/β-catenin and MAPK pathway in hair follicles. PMID:26268840

  5. 76 FR 3152 - Agency Information Collection Activity: 1010-NEW, Upcoming Projects Considering the Use of Outer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-19

    ... September 7, 2010, we published a Federal Register notice (75 FR 54369) announcing that we would submit this...: 1010-NEW, Upcoming Projects Considering the Use of Outer Continental Shelf (OCS) Sand, Gravel, and... respondents will submit to BOEMRE to obtain OCS sand, gravel, and shell resources for use in shore...

  6. 76 FR 5189 - BOEMRE Information Collection Activities: 1010-0081, Operations in the Outer Continental Shelf...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-28

    ...To comply with the Paperwork Reduction Act of 1995 (PRA), we are notifying the public that we have submitted to OMB an information collection request (ICR) to renew approval of the paperwork requirements in the regulations under 30 CFR 282, Operations in the Outer Continental Shelf for Minerals Other than Oil, Gas, and Sulphur. This notice also provides the public a second opportunity to......

  7. 77 FR 15118 - Information Collection Activities: Operations in the Outer Continental Shelf for Minerals Other...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-14

    ... Continental Shelf for Minerals Other Than Oil, Gas, and Sulphur; Submitted for Office of Management and Budget... Continental Shelf for Minerals Other than Oil, Gas, and Sulphur. This notice also provides the public a second... 282, Operations in the Outer Continental Shelf for Minerals Other than Oil, Gas, and Sulphur....

  8. Mild maternal iron deficiency anemia induces DPOAE suppression and cochlear hair cell apoptosis by caspase activation in young guinea pigs.

    PubMed

    Yu, Fei; Hao, Shuai; Zhao, Yue; Ren, Yahao; Yang, Jun; Sun, Xiance; Chen, Jie

    2014-01-01

    Iron deficiency (ID) anemia (IDA) alters auditory neural normal development in the mammalian cochlea. Previous results suggest that mild maternal IDA during pregnancy and lactation altered the hearing and nervous system development of the young offspring, but the mechanisms underlying the association are incompletely understood. The objective of this study was to evaluate the role of apoptosis in the development of sensory hair cells following mild maternal IDA during pregnancy and lactation. We established a maternal anemia model in female guinea pigs by using a mild iron deficient diet. The offspring were weaned on postnatal day (PND) 9 and then was given the iron sufficient diet. Maternal blood samples were collected on gestational day (GD) 21, GD 42, GD 63 and PND 9, serum level of iron (SI) or hemoglobin (Hb) was measured. Blood samples of pups were collected on PND 9 for SI measurement. On PND 24, pups were examined the distortion product otoacoustic emission (DPOAE) task, and then the cochleae were harvested for assessment of apoptosis by immunohistochemistry of cysteine-aspartic acid proteases 3/9 (caspase-3/9) and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay, and by double immunofluorescence for the colocalization of TUNEL and caspase-3. Blood samples of pups were collected on PND 24 for SI and Hb measurements. Here we show that mild maternal IDA during pregnancy and lactation resulted in hearing impairment, decreased hair cell number, caspase-3/9 activation and increased apoptotic cell number of young guinea pigs. These results indicate a key role for apoptosis in inhibition of hair cell development, caused by mild maternal IDA during pregnancy and lactation. PMID:24378594

  9. VEGF induces proliferation of human hair follicle dermal papilla cells through VEGFR-2-mediated activation of ERK

    SciTech Connect

    Li, Wei; Man, Xiao-Yong; Li, Chun-Ming; Chen, Jia-Qi; Zhou, Jiong; Cai, Sui-Qing; Lu, Zhong-Fa; Zheng, Min

    2012-08-15

    Vascular endothelial growth factor (VEGF) is one of the strongest regulators of physiological and pathological angiogenesis. VEGF receptor 2 (VEGFR-2), the primary receptor for VEGF, is thought to mediate major functional effects of VEGF. Previously, we have localized both VEGF and VEGFR-2 in human hair follicles. In this study, we further defined the expression and roles of VEGFR-2 on human hair follicle dermal papilla (DP) cells. The expression of VEGFR-2 on DP cells was examined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis separately, and localization of VEGFR-2 was defined by immunofluorescence. The effect of VEGF on DP cells was analyzed by MTT assays and specific inhibitors. Finally, the role of VEGF involved in the signaling pathways was investigated by Western blot. RT-PCR and Western blot analysis demonstrated the expression of VEGFR-2 on DP cells. Immunostaining for VEGFR-2 showed strong signal on cultured human DP cells in vitro. Exogenous VEGF{sub 165} stimulated proliferation of DP cells in a dose-dependent manner. Furthermore, this stimulation was blocked by a VEGFR-2 neutralizing antibody (MAB3571) and an ERK inhibitor (PD98059). VEGF{sub 165}-induced phosphorylation of ERK1/2 was abolished by MAB3571 and PD98059, while the phosphorylation of p38, JNK and AKT were not changed by VEGF{sub 165}. Taken together, VEGFR-2 is expressed on primary human hair follicle DP cells and VEGF induces proliferation of DP cells through VEGFR-2/ERK pathway, but not p38, JNK or AKT signaling. -- Highlights: Black-Right-Pointing-Pointer We examine the expression of VEGFR-2 on cultured human dermal papilla (DP) cells. Black-Right-Pointing-Pointer VEGF{sub 165} stimulated proliferation of human DP cells in a dose-dependent manner. Black-Right-Pointing-Pointer This stimulation was through VEGFR-2-mediated activation of ERK.

  10. Sequence analysis, expression, and binding activity of recombinant major outer sheath protein (Msp) of Treponema denticola.

    PubMed Central

    Fenno, J C; Müller, K H; McBride, B C

    1996-01-01

    The gene encoding the major outer sheath protein (Msp) of the oral spirochete Treponema denticola ATCC 35405 was cloned, sequenced, and expressed in Escherichia coli. Preliminary sequence analysis showed that the 5' end of the msp gene was not present on the 5.5-kb cloned fragment described in a recent study (M. Haapasalo, K. H. Müller, V. J. Uitto, W. K. Leung, and B. C. McBride, Infect. Immun. 60:2058-2065,1992). The 5' end of msp was obtained by PCR amplification from a T. denticola genomic library, and an open reading frame of 1,629 bp was identified as the coding region for Msp by combining overlapping sequences. The deduced peptide consisted of 543 amino acids and had a molecular mass of 58,233 Da. The peptide had a typical prokaryotic signal sequence with a potential cleavage site for signal peptidase 1. Northern (RNA) blot analysis showing the msp transcript to be approximately 1.7 kb was consistent with the identification of a promoter consensus sequence located optimally upstream of msp and a transcription termination signal found downstream of the stop codon. The entire msp sequence was amplified from T. denticola genomic DNA and cloned in E. coli by using a tightly regulated T7 RNA polymerase vector system. Expression of Msp was toxic to E. coli when the entire msp gene was present. High levels of Msp were produced as inclusion bodies when the putative signal peptide sequence was deleted and replaced by a vector-encoded T7 peptide sequence. Recombinant Msp purified to homogeneity from a clone containing the full-length msp gene adhered to immobilized laminin and fibronectin but not to bovine serum albumin. Attachment of recombinant Msp was decreased in the presence of soluble substrate. Attachment of T. denticola to immobilized laminin and fibronectin was increased by pretreatment of the substrate with recombinant Msp. These studies lend further support to the hypothesis that Msp mediates the extracellular matrix binding activity of T. denticola. PMID

  11. Plant Growth Promotion Activity of Keratinolytic Fungi Growing on a Recalcitrant Waste Known as “Hair Waste”

    PubMed Central

    Cavello, Ivana A.; Crespo, Juan M.; García, Sabrina S.; Zapiola, José M.; Luna, María F.; Cavalitto, Sebastián F.

    2015-01-01

    Purpureocillium lilacinum (Thom) Samsom is one of the most studied fungi in the control of plant parasitic nematodes. However, there is not specific information on its ability to inhibit some pathogenic bacteria, fungi, or yeast. This work reports the production of several antifungal hydrolytic enzymes by a strain of P. lilacinum when it is grown in a medium containing hair waste. The growth of several plant-pathogenic fungi, Alternaria alternata, Aspergillus niger, and Fusarium culmorum, was considerably affected by the presence of P. lilacinum's supernatant. Besides antifungal activity, P. lilacinum demonstrates the capability to produce indoleacetic acid and ammonia during time cultivation on hair waste medium. Plant growth-promoting activity by cell-free supernatant was evidenced through the increase of the percentage of tomato seed germination from 71 to 85% after 48 hours. A 21-day plant growth assay using tomato plants indicates that crude supernatant promotes the growth of the plants similar to a reference fertilizer (p > 0.05). These results suggest that both strain and the supernatant may have potential to be considered as a potent biocontrol agent with multiple plant growth-promoting properties. To our knowledge, this is the first report on the antifungal, IAA production and tomato growth enhancing compounds produced by P. lilacinum LPSC #876. PMID:26697226

  12. Removing Hair Safely

    MedlinePlus

    ... the skin, and into the hair follicle. An electric current travels down the wire and destroys the hair ... a period of time. Tweezer epilators also use electric current to remove hair. The tweezers grasp the hair ...

  13. The Effect of Autologous Activated Platelet Rich Plasma (AA-PRP) Injection on Pattern Hair Loss: Clinical and Histomorphometric Evaluation

    PubMed Central

    Cervelli, V.; Garcovich, S.; Bielli, A.; Cervelli, G.; Curcio, B. C.; Scioli, M. G.; Orlandi, A.; Gentile, P.

    2014-01-01

    To investigate the safety and clinical efficacy of AA-PRP injections for pattern hair loss. AA-PRP, prepared from a small volume of blood, was injected on half of the selected patients' scalps with pattern hair loss. The other half was treated with placebo. Three treatments were given for each patient, with intervals of 1 month. The endpoints were hair re-growth, hair dystrophy as measured by dermoscopy, burning or itching sensation, and cell proliferation as measured by Ki-67 evaluation. At the end of the 3 cycles of treatment, the patients presented clinical improvement in the mean number of hairs, with a mean increase of 18.0 hairs in the target area, and a mean increase in total hair density of 27.7 ( number of hairs/cm2) compared with baseline values. Microscopic evaluation showed the increase of epidermis thickness and of the number of hair follicles two weeks after the last AA-PRP treatment compared to baseline value (P < 0.05). We also observed an increase of Ki67+ keratinocytes of epidermis and of hair follicular bulge cells and a slight increase of small blood vessels around hair follicles in the treated skin compared to baseline (P < 0.05). PMID:24883322

  14. Downregulation of the renal outer medullary K(+) channel ROMK by the AMP-activated protein kinase.

    PubMed

    Siraskar, Balasaheb; Huang, Dan Yang; Pakladok, Tatsiana; Siraskar, Gulab; Sopjani, Mentor; Alesutan, Ioana; Kucherenko, Yulia; Almilaji, Ahmad; Devanathan, Vasudharani; Shumilina, Ekaterina; Föller, Michael; Munoz, Carlos; Lang, Florian

    2013-02-01

    The 5'-adenosine monophosphate-activated serine/threonine protein kinase (AMPK) is stimulated by energy depletion, increase in cytosolic Ca(2+) activity, oxidative stress, and nitric oxide. AMPK participates in the regulation of the epithelial Na(+) channel ENaC and the voltage-gated K(+) channel KCNE1/KCNQ1. It is partially effective by decreasing PIP(2) formation through the PI3K pathway. The present study explored whether AMPK regulates the renal outer medullary K(+) channel ROMK. To this end, cRNA encoding ROMK was injected into Xenopus oocytes with and without additional injection of constitutively active AMPK(γR70Q) (AMPK(α1)-HA+AMPK(β1)-Flag+AMPKγ1(R70Q)), or of inactive AMPK(αK45R) (AMPK(α1K45R)+AMPK(β1)-Flag+AMPK(γ1)-HA), and the current determined utilizing two-electrode voltage-clamp and single channel patch clamp. ROMK protein abundance was measured utilizing chemiluminescence in Xenopus oocytes and western blot in whole kidney tissue. Moreover, renal Na(+) and K(+) excretion were determined in AMPK(α1)-deficient mice (ampk ( -/- )) and wild-type mice (ampk ( +/+ )) prior to and following an acute K(+) load (111 mM KCl, 30 mM NaHCO(3), 4.7 mM NaCl, and 2.25 g/dl BSA) at a rate of 500 μl/h. As a result, coexpression of AMPK(γR70Q) but not of AMPK(αK45R) significantly decreased the current in ROMK1-expressing Xenopus oocytes. Injection of phosphatidylinositol PI((4,5))P(2) significantly increased the current in ROMK1-expressing Xenopus oocytes, an effect reversed in the presence of AMPK(γR70Q). Under control conditions, no significant differences between ampk ( -/- ) and ampk ( +/+ ) mice were observed in glomerular filtration rate (GFR), urinary flow rate, serum aldosterone, plasma Na(+), and K(+) concentrations as well as absolute and fractional Na(+) and K(+) excretion. Following an acute K(+) load, GFR, urinary flow rate, serum aldosterone, plasma Na(+), and K(+) concentration were again similar in both genotypes, but renal absolute

  15. A LAMP-based schematic prototype instrument for detection of microorganisms in human outer space activities

    NASA Astrophysics Data System (ADS)

    Hu, Yongfei; Liu, Zhiheng; Li, Junxiong; Zhu, Baoli

    One of the main tasks of human outer space exploration is to detect signs of life. Based on meteoritic evidence, common ancestry hypothesis has been posed. Therefore, searching for the fundamental molecules (DNA, RNA, and proteins) that constitute life as we know on Earth is feasible and now the typical approach. To achieve this goal, portable, robust, and highly sensitive instrument is also needed. In this study, based on Loop mediated isothermal amplification (LAMP) technique that targets life information storage molecular, DNA, we designed a schematic prototype instrument for microorganism detection. First, we designed LAMP primers used for amplification of DNA markers of Bacteria, Archaea, and Fungus; then, we optimized the LAMP reaction system for space using; and finally, we designed a prototype instrument and operating software system that are compatible with the LAMP reaction system. The results of simulation experiments showed that our instrument performed well for detecting representative microorganisms and the device can achieve semi-automatization. The detection process, from sample preparation to signal visualization, was completed in 1.5 hour. Our study provides a new method and corresponding device for detection of DNA molecular, which has great potential for applications in outer space exploration. Besides, the instrument we designed can also been used for monitoring changes of terrestrial microorganisms in outer space, for example in aircraft.

  16. Multielement analysis of human hair and kidney stones by instrumental neutron activation analysis with the k0-standardization method.

    PubMed

    Abugassa, I; Sarmani, S B; Samat, S B

    1999-06-01

    This paper focuses on the evaluation of the k0 method of instrumental neutron activation analysis in biological materials. The method has been applied in multielement analysis of human hair standard reference materials from IAEA, No. 085, No. 086 and from NIES (National Institute for Environmental Sciences) No. 5. Hair samples from people resident in different parts of Malaysia, in addition to a sample from Japan, were analyzed. In addition, human kidney stones from members of the Malaysian population have been analyzed for minor and trace elements. More than 25 elements have been determined. The samples were irradiated in the rotary rack (Lazy Susan) at the TRIGA Mark II reactor of the Malaysian Institute for Nuclear Technology and Research (MINT). The accuracy of the method was ascertained by analysis of other reference materials, including 1573 tomato leaves and 1572 citrus leaves. In this method the deviation of the 1/E1+ alpha epithermal neutron flux distribution from the 1/E law (P/T ratio) for true coincidence effects of the gamma-ray cascade and the HPGe detector efficiency were determined and corrected for. PMID:10355102

  17. Treatment of MSCs with Wnt1a-conditioned medium activates DP cells and promotes hair follicle regrowth

    PubMed Central

    Dong, Liang; Hao, Haojie; Xia, Lei; Liu, Jiejie; Ti, Dongdong; Tong, Chuan; Hou, Qian; Han, Qingwang; Zhao, Yali; Liu, Huiling; Fu, Xiaobing; Han, Weidong

    2014-01-01

    Hair loss (alopecia) is a common problem for people. The dermal papilla is the key signaling center that regulates hair growth and it engage in crosstalk with the microenvironment, including Wnt signaling and stem cells. In this study, we explored the effects of bone marrow mesenchymal stem cell overexpression of Wnt1a on mouse hair follicle regeneration. Wnt-CM accelerated hair follicle progression from telogen to anagen and enhanced the ALP expression in the DP area. Moreover, the hair induction-related genes were upregulated, as demonstrated by qRT-PCR. Wnt-CM treatment restored and increased DP cell expression of genes downregulated by dihydrotestosterone treatment, as demonstrated by qRT-PCR assays. Our study reveals that BM-MSC-generated Wnt1a promotes the DP's ability to induce hair cycling and regeneration. PMID:24961246

  18. Treatment of MSCs with Wnt1a-conditioned medium activates DP cells and promotes hair follicle regrowth.

    PubMed

    Dong, Liang; Hao, Haojie; Xia, Lei; Liu, Jiejie; Ti, Dongdong; Tong, Chuan; Hou, Qian; Han, Qingwang; Zhao, Yali; Liu, Huiling; Fu, Xiaobing; Han, Weidong

    2014-01-01

    Hair loss (alopecia) is a common problem for people. The dermal papilla is the key signaling center that regulates hair growth and it engage in crosstalk with the microenvironment, including Wnt signaling and stem cells. In this study, we explored the effects of bone marrow mesenchymal stem cell overexpression of Wnt1a on mouse hair follicle regeneration. Wnt-CM accelerated hair follicle progression from telogen to anagen and enhanced the ALP expression in the DP area. Moreover, the hair induction-related genes were upregulated, as demonstrated by qRT-PCR. Wnt-CM treatment restored and increased DP cell expression of genes downregulated by dihydrotestosterone treatment, as demonstrated by qRT-PCR assays. Our study reveals that BM-MSC-generated Wnt1a promotes the DP's ability to induce hair cycling and regeneration. PMID:24961246

  19. EVOLUTION OF WARPED ACCRETION DISKS IN ACTIVE GALACTIC NUCLEI. I. ROLES OF FEEDING AT THE OUTER BOUNDARIES

    SciTech Connect

    Li, Yan-Rong; Wang, Jian-Min; Cheng, Cheng; Qiu, Jie

    2013-02-10

    We investigate the alignment processes of spinning black holes and their surrounding warped accretion disks in a frame of two different types of feeding at the outer boundaries. We consider (1) fixed flows in which gas is continually fed with a preferred angular momentum, and (2) free flows in which there is no gas supply and the disks diffuse freely at their outer edges. As expected, we find that for the cases of fixed flows the black hole disk systems always align on timescales of several 10{sup 6} yr, irrespective of the initial inclinations. If the initial inclination angles are larger than {pi}/2, the black hole accretion transits from retrograde to prograde fashion, and the accreted mass onto the black holes during these two phases is comparable. On the other hand, for the cases of free flows, both alignments and anti-alignments can occur, depending on the initial inclinations and the ratios of the angular momentum of the disks to that of the black holes. In such cases, the disks will be consumed within timescales of 10{sup 6} yr by black holes accreting at the Eddington limit. We propose that there is a close connection between the black hole spin and the lifetime for which the feeding persists, which determines the observable episodic lifetimes of active galactic nuclei. We conclude that careful inclusion of the disk feeding at the outer boundaries is crucial for modeling the evolution of the black hole spin.

  20. "My hair or my health:" Overcoming barriers to physical activity in African American women with a focus on hairstyle-related factors.

    PubMed

    Huebschmann, Amy G; Campbell, Lucille Johnson; Brown, Candace S; Dunn, Andrea L

    2016-01-01

    Physical activity disparities among African American (AA) women may be related to sociocultural barriers, including difficulties with restyling hair after exercise. We sought to identify physical activity barriers and facilitators in AA women with a focus on sociocultural factors related to hairstyle maintenance. Participants (n = 51) were AA women aged 19-73 years who completed valid surveys and participated in structured focus groups, stratified by age and physical activity levels, from November 2012 to February 2013. The Constant Comparison method was used to develop qualitative themes for barriers and facilitators. The most frequently reported general physical activity barrier among exercisers was "lack of money" (27%) and among non-exercisers was "lack of self-discipline" (57%). A hairstyle-related barrier of "sweating out my hairstyle" was reported by 7% of exercisers and 29% of non-exercisers. This hairstyle-related barrier included the need for extra time and money to restyle hair due to perspiration. Hairstyle-related facilitators included: prioritizing health over hairstyle and high self-efficacy to restyle hair after perspiration. Participants were interested in resources to simplify hairstyle maintenance. AA women whose hairstyle is affected by perspiration may avoid physical activity due to time and financial burdens. Increasing self-efficacy to restyle hair after perspiration may help to overcome this barrier. PMID:26495938

  1. Hair Loss

    MedlinePlus

    ... psychosocial impact of hair loss have found patients’ self-esteem, body image and self-confidence to be negatively ... 1-2 Known psychosocial complications include depression, low self-esteem, altered self-image, and less frequent and enjoyable ...

  2. Hair cell replacement in adult mouse utricles after targeted ablation of hair cells with diphtheria toxin.

    PubMed

    Golub, Justin S; Tong, Ling; Ngyuen, Tot B; Hume, Cliff R; Palmiter, Richard D; Rubel, Edwin W; Stone, Jennifer S

    2012-10-24

    We developed a transgenic mouse to permit conditional and selective ablation of hair cells in the adult mouse utricle by inserting the human diphtheria toxin receptor (DTR) gene into the Pou4f3 gene, which encodes a hair cell-specific transcription factor. In adult wild-type mice, administration of diphtheria toxin (DT) caused no significant hair cell loss. In adult Pou4f3(+/DTR) mice, DT treatment reduced hair cell numbers to 6% of normal by 14 days post-DT. Remaining hair cells were located primarily in the lateral extrastriola. Over time, hair cell numbers increased in these regions, reaching 17% of untreated Pou4f3(+/DTR) mice by 60 days post-DT. Replacement hair cells were morphologically distinct, with multiple cytoplasmic processes, and displayed evidence for active mechanotransduction channels and synapses characteristic of type II hair cells. Three lines of evidence suggest replacement hair cells were derived via direct (nonmitotic) transdifferentiation of supporting cells: new hair cells did not incorporate BrdU, supporting cells upregulated the pro-hair cell gene Atoh1, and supporting cell numbers decreased over time. This study introduces a new method for efficient conditional hair cell ablation in adult mouse utricles and demonstrates that hair cells are spontaneously regenerated in vivo in regions where there may be ongoing hair cell turnover. PMID:23100430

  3. LIPH Expression in Skin and Hair Follicles of Normal Coat and Rex Rabbits

    PubMed Central

    Diribarne, Mathieu; Mata, Xavier; Rivière, Julie; Bouet, Stéphan; Vaiman, Anne; Chapuis, Jérôme; Reine, Fabienne; Fleurot, Renaud; Auvinet, Gérard; Deretz, Séverine; Allain, Daniel; Schibler, Laurent; Cribiu, Edmond-Paul; Guérin, Gérard

    2012-01-01

    Natural mutations in the LIPH gene were shown to be responsible for hair growth defects in humans and for the rex short hair phenotype in rabbits. In this species, we identified a single nucleotide deletion in LIPH (1362delA) introducing a stop codon in the C-terminal region of the protein. We investigated the expression of LIPH between normal coat and rex rabbits during critical fetal stages of hair follicle genesis, in adults and during hair follicle cycles. Transcripts were three times less expressed in both fetal and adult stages of the rex rabbits than in normal rabbits. In addition, the hair growth cycle phases affected the regulation of the transcription level in the normal and mutant phenotypes differently. LIPH mRNA and protein levels were higher in the outer root sheath (ORS) than in the inner root sheath (IRS), with a very weak signal in the IRS of rex rabbits. In vitro transfection shows that the mutant protein has a reduced lipase activity compared to the wild type form. Our results contribute to the characterization of the LIPH mode of action and confirm the crucial role of LIPH in hair production. PMID:22272275

  4. Minocycline attenuates gentamicin induced hair cell loss in neonatal cochlear cultures.

    PubMed

    Corbacella, Elisa; Lanzoni, Irene; Ding, Dalian; Previati, Maurizio; Salvi, Richard

    2004-11-01

    Minocycline, a second-generation tetracycline antibiotic used against gram-negative and gram-positive bacteria, protects against a wide range of neurodegenerative disorders by inhibiting caspases, iNOS and the release of cytochrome c. Since aminoglycoside antibiotics damage sensory hair cells in the inner ear by activating caspase-mediated cell death pathways, we hypothesized that minocycline would protect against gentamicin (GM) ototoxicity. To test this hypothesis, postnatal day 3 (P3) rat, cochlear organotypic cultures were treated with GM alone or in combination with minocycline (10-500 microM). Treatment with GM induced a dose-dependent loss of outer hair cells (OHC) and inner hair cells (IHC). Addition of minocycline to the GM-treated cultures greatly reduced the amount of GM-induced hair cell damage in P3 cochlear cultures. The greatest protection was achieved with 100 microM of minocycline. Application of minocycline alone had no adverse effects on hair cell survival. The advantage of this combination therapy is that minocycline prevents GM-induced hair cell loss while helping to suppress the bacterial infection. PMID:15504599

  5. A novel cholinergic receptor mediates inhibition of chick cochlear hair cells.

    PubMed

    Fuchs, P A; Murrow, B W

    1992-04-22

    The central nervous system provides feedback regulation at several points within the peripheral auditory apparatus. One component of that feedback is inhibition of cochlear hair cells by release of acetylcholine (ACh) from efferent brainstem neurons. The mechanism of hair cell inhibition, and the character of the presumed cholinergic receptor, however, have eluded understanding. Both nicotinic and muscarinic, as well as some non-cholinergic ligands can affect the efferent action. We have made whole-cell, tight-seal recordings from short (outer) hair cells isolated from the chick's cochlea. These are the principal targets of cochlear efferents in birds. ACh hyperpolarizes short hair cells by opening a cation channel through which Ca2+ enters the cell and subsequently activates Ca(2+)-dependent K+ current (Fuchs & Murrow 1991, 1992). Both curare and atropine are effective-antagonists of cholinergic inhibition at 3 microM, whereas trimethaphan camsylate and strychnine block at 1 microM. The normally irreversible nicotinic antagonist, alpha-bungarotoxin, reversibly blocked the hair cell response, as did kappa-bungarotoxin. The half-blocking concentration for alpha-bungarotoxin was 26 nM. It is proposed that the hair cell AChR is a ligand-gated cation channel related to the nicotinic receptor of nerve and muscle. PMID:1355909

  6. Research Advances: Pacific Northwest National Laboratory Finds New Way to Detect Destructive Enzyme Activity--Hair Dye Relies on Nanotechnology--Ways to Increase Shelf Life of Milk

    ERIC Educational Resources Information Center

    King, Angela G.

    2007-01-01

    Recent advances in various research fields are described. Scientists at the Pacific Northwest National Laboratory have found a new way to detect destructive enzyme activity, scientists in France have found that an ancient hair dye used by ancient people in Greece and Rome relied on nanotechnology and in the U.S. scientists are developing new…

  7. Beyond the active site: the impact of the outer coordination sphere on electrocatalysts for hydrogen production and oxidation.

    PubMed

    Ginovska-Pangovska, Bojana; Dutta, Arnab; Reback, Matthew L; Linehan, John C; Shaw, Wendy J

    2014-08-19

    Redox active metalloenzymes play a major role in energy transformation reactions in biological systems. Examples include formate dehydrogenases, nitrogenases, CO dehydrogenase, and hydrogenases. Many of these reactions are also of interest to humans as potential energy storage or utilization reactions for photoelectrochemical, electrolytic, and fuel cell applications. These metalloenzymes consist of redox active metal centers where substrates are activated and undergo transformation to products accompanied by electron and proton transfer to or from the substrate. These active sites are typically buried deep within a protein matrix of the enzyme with channels for proton transport, electron transport, and substrate/product transport between the active site and the surface of the protein. In addition, there are amino acid residues that lie in close proximity to the active site that are thought to play important roles in regulating and enhancing enzyme activity. Directly studying the outer coordination sphere of enzymes can be challenging due to their complexity, and the use of modified molecular catalysts may allow us to provide some insight. There are two fundamentally different approaches to understand these important interactions. The "bottom-up" approach involves building an amino acid or peptide containing outer coordination sphere around a functional molecular catalyst, and the "top-down" approach involves attaching molecular catalyst to a structured protein. Both of these approaches have been undertaken for hydrogenase mimics and are the emphasis of this Account. Our focus has been to utilize amino acid or peptide based scaffolds on an active functional enzyme mimic for H2 oxidation and production, [Ni(P(R)2N(R('))2)2](2+). This "bottom-up" approach has allowed us to evaluate individual functional group and structural contributions to electrocatalysts for H2 oxidation and production. For instance, using amine, ether, and carboxylic acid functionalities in the

  8. Purification of outer membrane vesicles from Pseudomonas aeruginosa and their activation of an IL-8 response

    PubMed Central

    Bauman, Susanne J.; Kuehn, Meta J.

    2012-01-01

    Considerable lung injury results from the inflammatory response to Pseudomonas aeruginosa infections in patients with cystic fibrosis (CF). The P. aeruginosa laboratory strain PAO1, an environmental isolate, and isolates from CF patients were cultured in vitro and outer membrane vesicles from those cultures were quantitated, purified, and characterized. Vesicles were produced throughout the growth phases of the culture and vesicle yield was strain-independent. Strain-dependent differences in the protein composition of vesicles were quantitated and identified. The aminopeptidase PaAP (PA2939) was highly enriched in vesicles from CF isolates. Vesicles from all strains elicited IL-8 secretion by lung epithelial cells. These results suggest that P. aeruginosa colonizing the CF lung may produce vesicles with a particular composition and that the vesicles could contribute to inflammation. PMID:16807039

  9. Identifying water on our Moon and organics in the outer Solar System with active reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Hibbitts, C. A.; Spiers, G. D.; Hansen, G. B.

    2005-08-01

    Infrared reflectance spectroscopy has successfully characterized H2O and identified organic molecules on many Solar System objects. However, passive reflectance spectroscopy cannot detect water in the permanently shadowed regions of the Moon. Similarly, the mid-IR fingerprints of organics on the surfaces of outer solar system objects cannot be detected passively because the sunlight is too dim and the surfaces are too cold. The strongest absorption band for condensed water and ice is near 3 microns. Organic molecules have strong absorptions near 3.4 microns, with spectral fingerprints necessary for unique identification present from approximately 5 to 10 microns. Given a sufficiently strong source of illumination, water hidden in shadows on the Moon and organic molecules in the outer solar system would be detectable and identifiable. Quantum Cascade (QC) laser technology is now becoming sufficiently capable to support reflectance spectroscopy at some of these wavelengths from orbit. Conceived under the HCIPE program in support of Prometheus missions, this technique is intrinsically very scalable. For instance, water can be detected using only two wavelengths and its physical state can be characterized with only five. Requiring an optical power of 2W per wavelength for sufficient signal-to-noise, the total power consumption by the lasing system would be approximately 80 and 200W, respectively. Currently, a continuous power output at 3 μm of 200 mWatts has been demonstrated. With beam combining, an optical power of 2 Watts is currently achievable. On the Moon, this would enable the detection of as little as 100ppm water. Radar and neutron spectroscopy measurements suggest there may be > 1000 ppm of water-ice present in permanent crater shadows on the Moon [Feldman et al., 1998; 2000; Nozette et al., 1996] which, if present the surface regolith would stabily exist adsorbed on the grains [Hodges, 2002; Cocks et al., 2002].

  10. Quantifying Isoniazid Levels in Small Hair Samples: A Novel Method for Assessing Adherence during the Treatment of Latent and Active Tuberculosis

    PubMed Central

    Gerona, Roy; Wen, Anita; Chin, Aaron T.; Koss, Catherine A.; Bacchetti, Peter; Metcalfe, John; Gandhi, Monica

    2016-01-01

    Background Tuberculosis (TB) is the leading cause of death from an infectious pathogen worldwide and the most prevalent opportunistic infection in people living with HIV. Isoniazid preventive therapy (IPT) reduces the incidence of active TB and reduces morbidity and mortality in HIV-infected patients independently of antiretroviral therapy. However, treatment of latent or active TB is lengthy and inter-patient variability in pharmacokinetics and adherence common. Current methods of assessing adherence to TB treatment using drug levels in plasma or urine assess short-term exposure and pose logistical challenges. Drug concentrations in hair assess long-term exposure and have demonstrated pharmacodynamic relevance in HIV. Methods A large hair sample from a patient with active TB was obtained for assay development. Methods to pulverize hair and extract isoniazid were optimized and then the drug detected by liquid chromatography/ tandem mass spectrometry (LC/MS-MS). The method was validated for specificity, accuracy, precision, recovery, linearity and stability to establish the assay’s suitability for therapeutic drug monitoring (TDM). Hair samples from patients on directly-observe isoniazid-based latent or active TB therapy from the San Francisco Department of Public Health TB clinic were then tested. Results Our LC/MS-MS-based assay detected isoniazid in quantities as low as 0.02ng/mg using 10–25 strands hair. Concentrations in spiked samples demonstrated linearity from 0.05–50ng/mg. Assay precision and accuracy for spiked quality-control samples were high, with an overall recovery rate of 79.5%. In 18 patients with latent or active TB on treatment, isoniazid was detected across a wide linear dynamic range. Conclusions An LC-MS/MS-based assay to quantify isoniazid levels in hair with performance characteristics suitable for TDM was developed and validated. Hair concentrations of isoniazid assess long-term exposure and may be useful for monitoring adherence to

  11. Desmoglein 3 anchors telogen hair in the follicle.

    PubMed

    Koch, P J; Mahoney, M G; Cotsarelis, G; Rothenberger, K; Lavker, R M; Stanley, J R

    1998-09-01

    Little is known about the function of desmosomes in the normal structure and function of hair. Therefore, it was surprising that mice without desmoglein 3 (the autoantigen in pemphigus vulgaris) not only developed mucous membrane and skin lesions like pemphigus patients, but also developed hair loss. Analysis of this phenotype indicated that hair was normal through the first growth phase ('follicular neogenesis'). Around day 20, however, when the hair follicles entered the resting phase of the hair growth cycle (telogen), mice with a targeted disruption of the desmoglein 3 gene (DSG3-/-) lost hair in a wave-like pattern from the head to the tail. Hair then regrew and was lost again in the same pattern with the next synchronous hair cycle. In adults, hair was lost in patches. Gentle hair pulls with adhesive tape showed that anagen (growing) hairs were firmly anchored in DSG3-/- mice, but telogen hairs came out in clumps compared to that of DSG3+/- and +/+ littermates in which telogen hairs were firmly anchored. Histology of bald skin areas in DSG3-/- mice showed cystic telogen hair follicles without hair shafts. Histology of hair follicles in early telogen, just before clinical hair loss occurred, showed loss of cell adhesion (acantholysis) between the cells surrounding the telogen club and the basal layer of the outer root sheath epithelium. Electron microscopy revealed 'half-desmosomes' at the plasma membranes of acantholytic cells. Similar acantholytic histology and ultrastructural findings have been previously reported in skin and mucous membrane lesions of DSG3-/- mice and pemphigus vulgaris patients. Immunoperoxidase staining with an antibody raised against mouse desmoglein 3 showed intense staining on the cell surface of keratinocytes surrounding the telogen hair club in normal mice. Similar staining was seen in human telogen hair with an anti-human desmoglein 3 antibody. Finally, a scalp biopsy from a pemphigus vulgaris patient showed empty telogen hair

  12. Hair care and dyeing.

    PubMed

    Draelos, Zoe Diana

    2015-01-01

    Alopecia can be effectively camouflaged or worsened through the use of hair care techniques and dyeing. Proper hair care, involving hair styling and the use of mild shampoos and body-building conditioners, can amplify thinning scalp hair; however, chemical processing, including hair dyeing, permanent waving, and hair straightening, can encourage further hair loss through breakage. Many patients suffering from alopecia attempt to improve their hair through extensive manipulation, which only increases problems. Frequent haircuts to minimize split ends, accompanied by gentle handling of the fragile fibers, is best. This chapter offers the dermatologist insight into hair care recommendations for the alopecia patient. PMID:26370650

  13. Beyond the Active Site: The Impact of the Outer Coordination Sphere on Electrocatalysts for Hydrogen Production and Oxidation

    SciTech Connect

    Ginovska-Pangovska, Bojana; Dutta, Arnab; Reback, Matthew L.; Linehan, John C.; Shaw, Wendy J.

    2014-08-19

    Hydrogenase enzymes provide inspiration for investigations of molecular catalysts utilizing structural and functional mimics of the active site. However, the resulting active site mimics cannot match the combination of high rates and low overpotentials of the enzyme, suggesting that the rest of the protein scaffold, i.e., the outer coordination sphere, is necessary for the efficiency of hydrogenase. Therefore, inclusion of outer coordination sphere elements onto molecular catalysts may enable us to achieve and ultimately surpass the overall enzymatic efficiency. In an effort to identify and include the missing enzymatic features, there has been recent effort to understand the effect of outer coordination sphere elements on molecular catalysts for hydrogen oxidation and production. Our focus has been to utilize amino acid or peptide based scaffolds on an active functional mimic for hydrogen oxidation and production, [Ni(PR2NR’2)2]2+. This bottom-up approach, i.e, building an outer coordination sphere around a functional molecular catalyst, has allowed us to evaluate individual contributions to catalysis, including enhancing proton movement, concentrating substrate and introducing structural features to control reactivity. Collectively, these studies have resulted in catalysts that can operate faster, can operate at lower overpotentials, have enhanced water solubility, and/or can provide more stability to oxygen or extreme conditions such as strongly acidic or basic conditions than their unmodified parent complexes. Common mechanisms have yet to be defined to predictably control these processes but our growing knowledge in this area is essential for the eventual mimicry of enzymes for developing efficient molecular catalysts for practical use. This account reviews previously published work supported by the US DOE Basic Energy Sciences (BES), Physical Bioscience program, the Office of Science Early Career Research Program through the USDOE, BES, the Center for

  14. Hair follicle anatomy (image)

    MedlinePlus

    At the base of the hair follicle are sensory nerve fibers that wrap around each hair bulb. Bending the hair stimulates the nerve endings allowing a person to feel that the hair has been moved. One of the main functions of hair is to act ...

  15. The timing of protein kinase activation events in the cascade that regulates mitotic progression in Tradescantia stamen hair cells.

    PubMed Central

    Wolniak, S M; Larsen, P M

    1995-01-01

    Stamen hair cells of the spiderwort plant Tradescantia virginiana exhibit unusually predictable rates of progression through mitosis, particularly from the time of nuclear envelope breakdown (NEBD) through the initiation of cytokinesis. The predictable rate of progression through prometaphase and metaphase has made these cells a useful model system for the determination of the timing of regulatory events that trigger entry into anaphase. A number of studies suggest that the elevation of one or more protein kinase activities is a necessary prerequisite for entry into anaphase. The current experiments employ two strategies to test when these elevations in protein kinase activity actually occur during metaphase. In perfusions, we added the protein kinase inhibitors K-252a, staurosporine, or calphostin C to living stamen hair cells for 10-min intervals at known times during prometaphase or metaphase and monitored the subsequent rate of progression into anaphase. Metaphase transit times were altered as a function of the time of addition of K-252a or staurosporine to the cells; metaphase transit times were extended significantly by treatments initiated in prometaphase through early metaphase and again late in metaphase. Transit times were normal after treatments initiated in mid-metaphase, approximately 15 to 21 min after NEBD. Calphostin C had no significant effect on the metaphase transit times. In parallel, cells were microinjected with known quantities of a general-purpose protein kinase substrate peptide, VRKRTLRRL, at predefined time points during prometaphase and metaphase. At a cytosolic concentration of 100 nM to 1 microM, the peptide doubled or tripled the metaphase transit times when injected into the cytosol of mitotic cells within the first 4 min after NEBD, at any point from 7.5 to 9 min after NEBD, at any point from 14 to 16 min after NEBD, at 21 min after NEBD, or at 24 min after NEBD. At the concentration used and during these brief intervals, the

  16. Burst activity and ultrafast activation kinetics of CaV1.3 Ca2+ channels support presynaptic activity in adult gerbil hair cell ribbon synapses

    PubMed Central

    Zampini, Valeria; Johnson, Stuart L; Franz, Christoph; Knipper, Marlies; Holley, Matthew C; Magistretti, Jacopo; Masetto, Sergio; Marcotti, Walter

    2013-01-01

    Auditory information transfer to afferent neurons relies on precise triggering of neurotransmitter release at the inner hair cell (IHC) ribbon synapses by Ca2+ entry through CaV1.3 Ca2+ channels. Despite the crucial role of CaV1.3 Ca2+ channels in governing synaptic vesicle fusion, their elementary properties in adult mammals remain unknown. Using near-physiological recording conditions we investigated Ca2+ channel activity in adult gerbil IHCs. We found that Ca2+ channels are partially active at the IHC resting membrane potential (−60 mV). At −20 mV, the large majority (>70%) of Ca2+ channel first openings occurred with an estimated delay of about 50 μs in physiological conditions, with a mean open time of 0.5 ms. Similar to other ribbon synapses, Ca2+ channels in IHCs showed a low mean open probability (0.21 at −20 mV), but this increased significantly (up to 0.91) when Ca2+ channel activity switched to a bursting modality. We propose that IHC Ca2+ channels are sufficiently rapid to transmit fast signals of sound onset and support phase-locking. Short-latency Ca2+ channel opening coupled to multivesicular release would ensure precise and reliable signal transmission at the IHC ribbon synapse. PMID:23713031

  17. Organization of microtubules in cochlear hair cells.

    PubMed

    Furness, D N; Hackney, C M; Steyger, P S

    1990-07-01

    The organization of microtubules in hair cells of the guinea-pig cochlea has been investigated using transmission electron microscopy and correlated with the location of tubulin-associated immunofluorescence in surface preparations of the organ of Corti. Results from both techniques reveal consistent distributions of microtubules in inner and outer hair cells. In the inner hair cells, microtubules are most concentrated in the apex. Reconstruction from serial sections shows three main groups: firstly, in channels through the cuticular plate and in a discontinuous belt around its upper perimeter; secondly, forming a ring inside a rim extending down from the lower perimeter of the plate; and thirdly, in a meshwork underlying the main body of the plate. In the cell body, microtubules line the inner face of the subsurface cistern and extend longitudinally through a tubulo-vesicular track between the apex and base. In outer hair cells, the pattern of microtubules associated with the cuticular plate is similar, although there are fewer present than in inner hair cells. In outer hair cells from the apex of the cochlea, microtubules occur around an infracuticular protrusion of cuticular plate material. In the cell body, many more microtubules occur in the region below the nucleus compared with inner hair cells. The possible functions of microtubules in hair cells are discussed by comparison with those found in other systems. These include morphogenesis and maintenance of cell shape; intracellular transport, e.g., of neurotransmitter vesicles; providing a possible substrate for motility; mechanical support of structures associated with sensory transduction. PMID:2197374

  18. The Lipopeptide Antibiotic Paenibacterin Binds to the Bacterial Outer Membrane and Exerts Bactericidal Activity through Cytoplasmic Membrane Damage

    PubMed Central

    Huang, En

    2014-01-01

    Paenibacterin is a broad-spectrum lipopeptide antimicrobial agent produced by Paenibacillus thiaminolyticus OSY-SE. The compound consists of a cyclic 13-residue peptide and an N-terminal C15 fatty acyl chain. The mechanism of action of paenibacterin against Escherichia coli and Staphylococcus aureus was investigated in this study. The cationic lipopeptide paenibacterin showed a strong affinity for the negatively charged lipopolysaccharides (LPS) from the outer membrane of Gram-negative bacteria. Addition of LPS (100 μg/ml) completely eliminated the antimicrobial activity of paenibacterin against E. coli. The electrostatic interaction between paenibacterin and LPS may have displaced the divalent cations on the LPS network and thus facilitated the uptake of antibiotic into Gram-negative cells. Paenibacterin also damaged the bacterial cytoplasmic membrane, as evidenced by the depolarization of membrane potential and leakage of intracellular potassium ions from cells of E. coli and S. aureus. Therefore, the bactericidal activity of paenibacterin is attributed to disruption of the outer membrane of Gram-negative bacteria and damage of the cytoplasmic membrane of both Gram-negative and Gram-positive bacteria. Despite the evidence of membrane damage, this study does not rule out additional bactericidal mechanisms potentially exerted by paenibacterin. PMID:24561581

  19. Impaired culture generated cytotoxicity with preservation of spontaneous natural killer-cell activity in cartilage-hair hypoplasia

    SciTech Connect

    Pierce, G.F.; Brovall, C.; Schacter, B.Z.; Polmar, S.H.

    1983-06-01

    Recent studies of cartilage-hair hypoplasia (CHH), a form of short-limbed dwarfism, have shown that all affected individuals have a cellular proliferation defect that results in a cellular immunodeficiency. However, only a minority of CHH individuals suffer from severe, life-threatening infections. For this reason, relevant immune defense mechanisms that may be responsible for maintaining intact host defenses in the majority of CHH individuals were studied. Spontaneous and allogeneic culture-induced (mixed lymphocyte response-MLR) specific and nonspecific (NK-like) cytotoxic mechanisms were analyzed and correlated with lymphocyte subpopulations present in CHH and normal individuals. Spontaneous natural-killer (NK) activity was present at or above normal levels, but culture-induced specific cytotoxicity and NK-like cytotoxicity as well as NK-like activity by T cell lines were significantly reduced in CHH individuals. The generation of radiation-resistant cytotoxicity, which normally occurs during allogeneic MLR, was markedly diminished in CHH, and was correlated with the decreased proliferation observed in CHH cultures. Preservation of spontaneous NK activity and loss of all forms of culture-induced cytotoxicity was associated with an increase in the proportion of lymphocytes bearing a thymic independent NK phenotype, and a significant decrease in thymic derived cytolytic T cell sub-populations in CHH individuals. Therefore, an intact cellular cytotoxic effector mechanism has been identified in CHH (i.e., NK activity).

  20. Hair cells use active zones with different voltage dependence of Ca2+ influx to decompose sounds into complementary neural codes.

    PubMed

    Ohn, Tzu-Lun; Rutherford, Mark A; Jing, Zhizi; Jung, Sangyong; Duque-Afonso, Carlos J; Hoch, Gerhard; Picher, Maria Magdalena; Scharinger, Anja; Strenzke, Nicola; Moser, Tobias

    2016-08-01

    For sounds of a given frequency, spiral ganglion neurons (SGNs) with different thresholds and dynamic ranges collectively encode the wide range of audible sound pressures. Heterogeneity of synapses between inner hair cells (IHCs) and SGNs is an attractive candidate mechanism for generating complementary neural codes covering the entire dynamic range. Here, we quantified active zone (AZ) properties as a function of AZ position within mouse IHCs by combining patch clamp and imaging of presynaptic Ca(2+) influx and by immunohistochemistry. We report substantial AZ heterogeneity whereby the voltage of half-maximal activation of Ca(2+) influx ranged over ∼20 mV. Ca(2+) influx at AZs facing away from the ganglion activated at weaker depolarizations. Estimates of AZ size and Ca(2+) channel number were correlated and larger when AZs faced the ganglion. Disruption of the deafness gene GIPC3 in mice shifted the activation of presynaptic Ca(2+) influx to more hyperpolarized potentials and increased the spontaneous SGN discharge. Moreover, Gipc3 disruption enhanced Ca(2+) influx and exocytosis in IHCs, reversed the spatial gradient of maximal Ca(2+) influx in IHCs, and increased the maximal firing rate of SGNs at sound onset. We propose that IHCs diversify Ca(2+) channel properties among AZs and thereby contribute to decomposing auditory information into complementary representations in SGNs. PMID:27462107

  1. 76 FR 52006 - Information Collection Activity: Leasing of Minerals Other Than Oil, Gas and Sulphur in the Outer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-19

    ... Minerals Other Than Oil, Gas and Sulphur in the Outer Continental Shelf, Extension of a Collection... Leasing of Minerals Other than Oil, Gas and Sulphur in the Outer Continental Shelf (OMB No. 1010- 0082... Other than Oil, Gas, and Sulphur in the Outer Continental Shelf. OMB Control Number: 1010-0082....

  2. Hair bleach poisoning

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002702.htm Hair bleach poisoning To use the sharing features on this page, please enable JavaScript. Hair bleach poisoning occurs when someone swallows hair bleach or ...

  3. Changing Your Hair

    MedlinePlus

    ... Snowboarding, Skating Crushes What's a Booger? Changing Your Hair KidsHealth > For Kids > Changing Your Hair Print A ... straight when it's curly. Treatments That Can Damage Hair Are these treatments OK for kids? That's something ...

  4. Hair spray poisoning

    MedlinePlus

    Hair spray poisoning occurs when someone breathes in (inhales) hair spray or sprays it down their throat or ... The harmful ingredients in hair spray are: Carboxymethylcellulose ... Polyvinyl alcohol Propylene glycol Polyvinylpyrrolidone

  5. Live imaging the phagocytic activity of inner ear supporting cells in response to hair cell death.

    PubMed

    Monzack, E L; May, L A; Roy, S; Gale, J E; Cunningham, L L

    2015-12-01

    Hearing loss and balance disorders affect millions of people worldwide. Sensory transduction in the inner ear requires both mechanosensory hair cells (HCs) and surrounding glia-like supporting cells (SCs). HCs are susceptible to death from aging, noise overexposure, and treatment with therapeutic drugs that have ototoxic side effects; these ototoxic drugs include the aminoglycoside antibiotics and the antineoplastic drug cisplatin. Although both classes of drugs are known to kill HCs, their effects on SCs are less well understood. Recent data indicate that SCs sense and respond to HC stress, and that their responses can influence HC death, survival, and phagocytosis. These responses to HC stress and death are critical to the health of the inner ear. Here we have used live confocal imaging of the adult mouse utricle, to examine the SC responses to HC death caused by aminoglycosides or cisplatin. Our data indicate that when HCs are killed by aminoglycosides, SCs efficiently remove HC corpses from the sensory epithelium in a process that includes constricting the apical portion of the HC after loss of membrane integrity. SCs then form a phagosome, which can completely engulf the remaining HC body, a phenomenon not previously reported in mammals. In contrast, cisplatin treatment results in accumulation of dead HCs in the sensory epithelium, accompanied by an increase in SC death. The surviving SCs constrict fewer HCs and display impaired phagocytosis. These data are supported by in vivo experiments, in which cochlear SCs show reduced capacity for scar formation in cisplatin-treated mice compared with those treated with aminoglycosides. Together, these data point to a broader defect in the ability of the cisplatin-treated SCs, to preserve tissue health in the mature mammalian inner ear. PMID:25929858

  6. Proteomic Analysis of Hair Follicles

    NASA Astrophysics Data System (ADS)

    Ishioka, Noriaki; Terada, Masahiro; Yamada, Shin; Seki, Masaya; Takahashi, Rika; Majima, Hideyuki J.; Higashibata, Akira; Mukai, Chiaki

    2013-02-01

    Hair root cells actively divide in a hair follicle, and they sensitively reflect physical conditions. By analyzing the human hair, we can know stress levels on the human body and metabolic conditions caused by microgravity environment and cosmic radiation. The Japan Aerospace Exploration Agency (JAXA) has initiated a human research study to investigate the effects of long-term space flight on gene expression and mineral metabolism by analyzing hair samples of astronauts who stayed in the International Space Station (ISS) for 6 months. During long-term flights, the physiological effects on astronauts include muscle atrophy and bone calcium loss. Furthermore, radiation and psychological effects are important issue to consider. Therefore, an understanding of the effects of the space environment is important for developing countermeasures against the effects experienced by astronauts. In this experiment, we identify functionally important target proteins that integrate transcriptome, mineral metabolism and proteome profiles from human hair. To compare the protein expression data with the gene expression data from hair roots, we developed the protein processing method. We extracted the protein from five strands of hair using ISOGEN reagents. Then, these extracted proteins were analyzed by LC-MS/MS. These collected profiles will give us useful physiological information to examine the effect of space flight.

  7. Mycophenolate antagonizes IFN-γ-induced catagen-like changes via β-catenin activation in human dermal papilla cells and hair follicles.

    PubMed

    Ryu, Sunhyo; Lee, Yonghee; Hyun, Moo Yeol; Choi, Sun Young; Jeong, Kwan Ho; Park, Young Min; Kang, Hoon; Park, Kui Young; Armstrong, Cheryl A; Johnson, Andrew; Song, Peter I; Kim, Beom Joon

    2014-01-01

    Recently, various immunosuppressant drugs have been shown to induce hair growth in normal hair as well as in alopecia areata and androgenic alopecia; however, the responsible mechanism has not yet been fully elucidated. In this study, we investigate the influence of mycophenolate (MPA), an immunosuppressant, on the proliferation of human dermal papilla cells (hDPCs) and on the growth of human hair follicles following catagen induction with interferon (IFN)-γ. IFN-γ was found to reduce β-catenin, an activator of hair follicle growth, and activate glycogen synthase kinase (GSK)-3β, and enhance expression of the Wnt inhibitor DKK-1 and catagen inducer transforming growth factor (TGF)-β2. IFN-γ inhibited expression of ALP and other dermal papillar cells (DPCs) markers such as Axin2, IGF-1, and FGF 7 and 10. MPA increased β-catenin in IFN-γ-treated hDPCs leading to its nuclear accumulation via inhibition of GSK3β and reduction of DKK-1. Furthermore, MPA significantly increased expression of ALP and other DPC marker genes but inhibited expression of TGF-β2. Therefore, we demonstrate for the first time that IFN-γ induces catagen-like changes in hDPCs and in hair follicles via inhibition of Wnt/β-catenin signaling, and that MPA stabilizes β-catenin by inhibiting GSK3β leading to increased β-catenin target gene and DP signature gene expression, which may, in part, counteract IFN-γ-induced catagen in hDPCs. PMID:25247578

  8. Mycophenolate Antagonizes IFN-γ-Induced Catagen-Like Changes via β-Catenin Activation in Human Dermal Papilla Cells and Hair Follicles

    PubMed Central

    Ryu, Sunhyo; Lee, Yonghee; Hyun, Moo Yeol; Choi, Sun Young; Jeong, Kwan Ho; Park, Young Min; Kang, Hoon; Park, Kui Young; Armstrong, Cheryl A.; Johnson, Andrew; Song, Peter I.; Kim, Beom Joon

    2014-01-01

    Recently, various immunosuppressant drugs have been shown to induce hair growth in normal hair as well as in alopecia areata and androgenic alopecia; however, the responsible mechanism has not yet been fully elucidated. In this study, we investigate the influence of mycophenolate (MPA), an immunosuppressant, on the proliferation of human dermal papilla cells (hDPCs) and on the growth of human hair follicles following catagen induction with interferon (IFN)-γ. IFN-γ was found to reduce β-catenin, an activator of hair follicle growth, and activate glycogen synthase kinase (GSK)-3β, and enhance expression of the Wnt inhibitor DKK-1 and catagen inducer transforming growth factor (TGF)-β2. IFN-γ inhibited expression of ALP and other dermal papillar cells (DPCs) markers such as Axin2, IGF-1, and FGF 7 and 10. MPA increased β-catenin in IFN-γ-treated hDPCs leading to its nuclear accumulation via inhibition of GSK3β and reduction of DKK-1. Furthermore, MPA significantly increased expression of ALP and other DPC marker genes but inhibited expression of TGF-β2. Therefore, we demonstrate for the first time that IFN-γ induces catagen-like changes in hDPCs and in hair follicles via inhibition of Wnt/β-catenin signaling, and that MPA stabilizes β-catenin by inhibiting GSK3β leading to increased β-catenin target gene and DP signature gene expression, which may, in part, counteract IFN-γ-induced catagen in hDPCs. PMID:25247578

  9. Elongated Structure of the Outer-Membrane Activator of Peptidoglycan Synthesis LpoA: Implications for PBP1A Stimulation

    PubMed Central

    Jean, Nicolas L.; Bougault, Catherine M.; Lodge, Adam; Derouaux, Adeline; Callens, Gilles; Egan, Alexander J.F.; Ayala, Isabel; Lewis, Richard J.; Vollmer, Waldemar; Simorre, Jean-Pierre

    2014-01-01

    Summary The bacterial cell envelope contains the stress-bearing peptidoglycan layer, which is enlarged during cell growth and division by membrane-anchored synthases guided by cytoskeletal elements. In Escherichia coli, the major peptidoglycan synthase PBP1A requires stimulation by the outer-membrane-anchored lipoprotein LpoA. Whereas the C-terminal domain of LpoA interacts with PBP1A to stimulate its peptide crosslinking activity, little is known about the role of the N-terminal domain. Herein we report its NMR structure, which adopts an all-α-helical fold comprising a series of helix-turn-helix tetratricopeptide-repeat (TPR)-like motifs. NMR spectroscopy of full-length LpoA revealed two extended flexible regions in the C-terminal domain and limited, if any, flexibility between the N- and C-terminal domains. Analytical ultracentrifugation and small-angle X-ray scattering results are consistent with LpoA adopting an elongated shape, with dimensions sufficient to span from the outer membrane through the periplasm to interact with the peptidoglycan synthase PBP1A. PMID:24954617

  10. Two substorm studies of relations between westward electric fields in the outer plasmasphere, auroral activity, and geomagnetic perturbations

    NASA Technical Reports Server (NTRS)

    Carpenter, D. L.; Akasofu, S.

    1972-01-01

    Temporal variations of the westward component of the magnetospheric convection electric field in the outer plasmasphere were compared to auroral activity near L = 7, and to variations in the geomagnetic field at middle and high latitudes. The substorms occurred on July 29, 1965 near 0530 UT and on August 20, 1965 near 0730 UT. The results on westward electric field E(w) were obtained by the whistler method using data from Eights, Antarctica (L is approximately 4). All sky camera records were obtained from Byrd, Antarctica, (L is approximately 7), located within about 1 hour of Eights in magnetic local time. It was found that E(w) within the outer plasmasphere increased rapidly to substorm levels about the time of auroral expansion at nearby longitudes. This behavior is shown to differ from results on E(w) from balloons, which show E(w) reaching enhanced levels prior to the expansion. A close temporal relation was found between the rapid, substorm associated increases in E(w) and a well known type of nightside geomagnetic perturbation. Particularly well defined was the correlation of E(w) rise and a large deviation of the D component at middle latitudes.

  11. Hair follicle dermal stem cells regenerate the dermal sheath, repopulate the dermal papilla, and modulate hair type.

    PubMed

    Rahmani, Waleed; Abbasi, Sepideh; Hagner, Andrew; Raharjo, Eko; Kumar, Ranjan; Hotta, Akitsu; Magness, Scott; Metzger, Daniel; Biernaskie, Jeff

    2014-12-01

    The dermal papilla (DP) provide instructive signals required to activate epithelial progenitors and initiate hair follicle regeneration. DP cell numbers fluctuate over the hair cycle, and hair loss is associated with gradual depletion/atrophy of DP cells. How DP cell numbers are maintained in healthy follicles remains unclear. We performed in vivo fate mapping of adult hair follicle dermal sheath (DS) cells to determine their lineage relationship with DP and found that a subset of DS cells are retained following each hair cycle, exhibit self-renewal, and repopulate the DS and the DP with new cells. Ablating these hair follicle dermal stem cells and their progeny retarded hair regrowth and altered hair type specification, suggesting that they function to modulate normal DP function. This work identifies a bipotent stem cell within the adult hair follicle mesenchyme and has important implications toward restoration of hair growth after injury, disease, and aging. PMID:25465495

  12. Hair dye poisoning

    MedlinePlus

    Hair tint poisoning ... Different types of hair dye contain different harmful ingredients. The harmful ingredients in permanent dyes are: Naphthylamine Other aromatic amino compounds Phenylenediamines Toluene ...

  13. African American Women, Hair Care, and Health Barriers

    PubMed Central

    Mahan, Meredith Grace

    2014-01-01

    Objectives: The objective of this study was to elucidate the prevalence of hair loss among African American women; explore the psychosocial impact of hair grooming difficulties; and examine both perceptions related to physician encounters in this group and the relationship between hair grooming, physical activity, and weight maintenance. Design: An anonymous retrospective and qualitative survey, the Hair Care Assessment Survey, is an 18-question novel survey instrument designed at the Henry Ford Hospital Department of Dermatology Multicultural Dermatology Center. Setting: The Hair Care Assessment Survey was distributed at church-related functions at predominantly African American metropolitan Detroit churches. Participants: Two hundred African American women from metropolitan Detroit, Michigan, aged 21 to 83. Measurements: The Hair Care Assessment Survey collected data relating to hair loss and hair care, psychosocial experiences relating to hair loss, and hair care as it relates to exercise and body weight management. Data was collected on doctor-patient hair-related medical visits and experiences with commercially available ethnic hair care products. Results: More than 50 percent reported excessive hair loss. Twenty-eight percent had visited a physician to discuss hair issues, but only 32 percent felt their physician understood African American hair. Forty-five percent reported avoiding exercise because of hair concerns, and 22 percent felt that their hair impeded maintaining healthy body weight. Conclusion: Hair loss affects a compelling number of African American women, and a significant number express dissatisfaction in hair-related physician encounters. Additionally, hair styling problems present a serious impediment to physical activity and weight management among this already high-risk population. PMID:25276273

  14. Assessment of protease activity in hydrolysed extracts from SSF of hair waste by and indigenous consortium of microorganisms.

    PubMed

    Yazid, Noraziah Abu; Barrena, Raquel; Sánchez, Antoni

    2016-03-01

    Hair wastes from the tannery industry were assessed for its suitability as substrates for protease production by solid-state fermentation (SSF) using a pilot-batch mode operation and anaerobically digested sludge as co-substrate. Maximum protease activity (52,230±1601Ug(-1)DM) was observed at the 14th day of SSF. Single step purification resulted in 2 fold purification with 74% of recovery by ultrafiltration with 10kDa cut-off. The recovered enzyme was stable at a temperature of 30°C and pH 11; optimal conditions that were determined by a central composite full factorial experimental design. The enzyme activity was inhibited by phenylmethylsulfonyl fluoride, which indicates that it belongs to serine protease group. The remaining solid material after protease extraction could be easily stabilized to obtain a final good quality compost-like material as the final dynamic respiration index was lower than 1gO2kg(-1)OMh(-1). The lyophilized recovered enzymes were a good alternative in the process of cowhides dehairing with respect to the current chemical treatment, avoiding the production of solid wastes and highly polluted wastewaters. In conclusion, the entire process can be considered a low-cost sustainable technology for the dehairing process, closing the organic matter cycle in the form of value added product and a compost-like material from a waste. PMID:26856443

  15. Pharmacological evaluation of Mallotus philippinensis (Lam.) Muell.-Arg. fruit hair extract for anti-inflammatory, analgesic and hypnotic activity

    PubMed Central

    Gangwar, Mayank; Gautam, Manish Kumar; Ghildiyal, Shivani; Nath, Gopal; Goel, Raj Kumar

    2016-01-01

    Objective: Recently, we observed wound healing activity of 50% ethanol extract of Mallotus philippinensis Muell. Arg (MP) fruit hairs extract (MPE). In several intestinal infections, localized inflammation is of common occurrence and hence we evaluated the anti-inflammatory, analgesic and hypnotic activity of MPE in different rat experimental models. Materials and Methods: Anti-inflammatory activity was evaluated by carrageenan (acute) and turpentine oil induced formalin (subacute) induced paw edema and while granuloma pouch (subacute) in rats. Analgesic and hypnotic activity of MPE was undertaken by tail-flick, hot-plate, and acetic acid-induced writhing tests while pentobarbitone-induced hypnotic potentiation in rats. Results: MPE at a dose of 200 mg/kg at 3 h after their administration showed inhibition of formalin-induced paw edema by 41.60% (P < 0.001) and carrageenan-induced paw edema by 55.30% (P < 0.001). After 7 days of treatments, MPE showed 38.0% (P < 0.001) inhibition against formalin-induced paw edema and reduced weight of turpentine-induced granuloma pouch by 29.6% (P < 0.01) and volume of exudates by 26.1% (P < 0.01), respectively. MPE (200 mg/kg) showed dose-dependent elevation in pain threshold and peak analgesic effect at 120 min as evidenced by increased latency period in tail flick method and increased reaction time in the hot-plate test while the reduction in the number of acetic acid-induced writhes by 45.7% (P < 0.001). The pentobarbitone-induced hypnosis model showed potentiation, as defined by increased duration of sleep in treated group rats as compared to control. Conclusion: Thus, the study revealed MPE is effective in reducing acute and subacute inflammation and showed effective and similar analgesic activity. This seemed to be safe in the treatment of pain and inflammation. PMID:27069718

  16. 78 FR 8190 - Commercial Wind Leasing and Site Assessment Activities on the Atlantic Outer Continental Shelf...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-05

    ...BOEM is reopening the comment period announced in the Notice of Intent to Prepare an Environmental Assessment (EA) for Commercial Wind Leasing and Site Assessment Activities on the OCS Offshore North...

  17. Physiological Maturation of Regenerating Hair Cells

    NASA Technical Reports Server (NTRS)

    Baird, Richard A.

    2003-01-01

    The bullfrog saccule, a sensor of gravity and substrate-borne vibration, is a model system for hair cell transduction. Saccular hair cells also increase in number throughout adult life and rapidly recover after hair cell damage, making this organ an ideal system for studying hair cell development, repair, and regeneration. We have used of hair cell and supporting cell immunocytochemical markers to identify damaged hair cells and hair cell precursors in organotypic cultures of the bullfrog saccule. We then used an innovative combination of confocal, electron, and time-lapse microscopy to study the fate of damaged hair cells and the origin of new hair cells after gentamicin ototoxicity in normal and mitotically blocked saccular cultures. These studies have shown that gentamicin ototoxicity produces both lethal and sublethal hair cell damage. They have also shown that hair cell recovery in this organ takes place by both the repair of sublethally damaged hair cells and by the replacement of lost hair cells by mitotic regeneration. In parallel studies, we have used biophysical and molecular biological techniques to study the differentiation and innervation of developing, repairing, and regenerating hair cells. More specifically, we have used RT-PCR to obtain the bullfrog homologues of L-type voltage- gated calcium (L-VGCC) and large-conductance Ca(2+)-activated potassium (BK) channel genes. We have then obtained probes for these genes and, using in situ hybridization, begun to examine their expression in the bullfrog saccule and amphibian papilla. We have also used fluorescent-labeled channel toxins and channel toxin derivatives to determine the time of appearance of L-type voltage-gated calcium (L-VGCC) and Ca(2+)-activated potassium (BK) channels and to study dynamic changes in the number, distribution, and co-localization of these proteins in developing, repairing, and regenerating hair cells. Using time-lapse microscopy, we are also studying the dynamic relationship

  18. 78 FR 33908 - Commercial Wind Lease Issuance and Site Assessment Activities on the Atlantic Outer Continental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ... identified Wind Energy Area (WEA) on the OCS offshore Rhode Island (RI) and Massachusetts (MA). The revised... from leasing, site characterization, and site assessment in and around the Call Area (76 FR 51391). The... Bureau of Ocean Energy Management Commercial Wind Lease Issuance and Site Assessment Activities on...

  19. 77 FR 39508 - Commercial Wind Lease Issuance and Site Assessment Activities on the Atlantic Outer Continental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-03

    ... specific project proposals on those leases) in an identified Wind Energy Area (WEA) on the OCS offshore..., site characterization, and site assessment in and around the Call Area (76 FR 51391). The Call Area is... Bureau of Ocean Energy Management Commercial Wind Lease Issuance and Site Assessment Activities on...

  20. Assembling Composite Dermal Papilla Spheres with Adipose-derived Stem Cells to Enhance Hair Follicle Induction.

    PubMed

    Huang, Chin-Fu; Chang, Ya-Ju; Hsueh, Yuan-Yu; Huang, Chia-Wei; Wang, Duo-Hsiang; Huang, Tzu-Chieh; Wu, Yi-Ting; Su, Fong-Chin; Hughes, Michael; Chuong, Cheng-Ming; Wu, Chia-Ching

    2016-01-01

    Intradermal adipose tissue plays an essential role for hair follicles (HFs) regeneration by regulating hair cycles. However, the effect of reconstruction of HFs and the involvement of adipose-related cells are poorly understood. We investigated assembly strategies for the interactions of dermal papilla (DP) cells with adipose-derived stem cells (ASCs) in promoting hair formation. DP cells lose DP traits during adherent culture, but preserved DP markers with a unified sphere diameter by seeding on chitosan-coated microenvironments. Next, ASCs isolated from rats were co-cultured with DP spheres by different assembling approaches to determine their interactions; a mixed sphere of ASCs with DP cells (MA-DPS), or a core-shell structure, outer ASCs shell and an inner DP core (CSA-DPS). CSA-DPS exhibited superior DP characteristics compared to MA-DPS. Conditional medium from ASCs, but not differentiated adipocytes, promoted DP markers and functional alkaline phosphatase activity from the DP cells. In vivo patch assay showed the core-shell assembling of CSA-DPS can reconstruct cellular arrangements and microenvironmental niches as dominated by PPARα signal in ASCs to induce the greater hair induction than MA-DPS or DP spheres alone. Therefore, the assembling of a core-shell sphere for DP with ASCs could reconstruct the HF cellular arrangement for hair formation. This paper set the groundwork for further evaluation of the input of other cell types. PMID:27210831

  1. Assembling Composite Dermal Papilla Spheres with Adipose-derived Stem Cells to Enhance Hair Follicle Induction

    PubMed Central

    Huang, Chin-Fu; Chang, Ya-Ju; Hsueh, Yuan-Yu; Huang, Chia-Wei; Wang, Duo-Hsiang; Huang, Tzu-Chieh; Wu, Yi-Ting; Su, Fong-Chin; Hughes, Michael; Chuong, Cheng-Ming; Wu, Chia-Ching

    2016-01-01

    Intradermal adipose tissue plays an essential role for hair follicles (HFs) regeneration by regulating hair cycles. However, the effect of reconstruction of HFs and the involvement of adipose-related cells are poorly understood. We investigated assembly strategies for the interactions of dermal papilla (DP) cells with adipose-derived stem cells (ASCs) in promoting hair formation. DP cells lose DP traits during adherent culture, but preserved DP markers with a unified sphere diameter by seeding on chitosan-coated microenvironments. Next, ASCs isolated from rats were co-cultured with DP spheres by different assembling approaches to determine their interactions; a mixed sphere of ASCs with DP cells (MA-DPS), or a core-shell structure, outer ASCs shell and an inner DP core (CSA-DPS). CSA-DPS exhibited superior DP characteristics compared to MA-DPS. Conditional medium from ASCs, but not differentiated adipocytes, promoted DP markers and functional alkaline phosphatase activity from the DP cells. In vivo patch assay showed the core-shell assembling of CSA-DPS can reconstruct cellular arrangements and microenvironmental niches as dominated by PPARα signal in ASCs to induce the greater hair induction than MA-DPS or DP spheres alone. Therefore, the assembling of a core-shell sphere for DP with ASCs could reconstruct the HF cellular arrangement for hair formation. This paper set the groundwork for further evaluation of the input of other cell types. PMID:27210831

  2. Study of hair surface energy and conditioning.

    PubMed

    Gao, Timothy; He, Yingxia; Landa, Peter; Tien, Jung-Mei

    2011-01-01

    A new test method has been developed to determine surface energy of hair fibers through measurements of contact angles at two hair/liquid interfaces. By measuring changes in surface energy of the same hair fiber before and after a cosmetic treatment, effects of active ingredients and the performance of tested formulations can be evaluated.The establishment of the method is based on Fowkes theory (1,2) described with two components, a dispersive and a non-dispersive component. The non-polar liquid used in this study was diiodomethane, and the polar liquid was benzyl alcohol. A Kruss 100 Tensiometer was used to measure contact angles of hair fibers. Virgin dark brown and regular bleached hairs were treated with selected conditioner formulations. Reductions in combing forces of hair tresses before and after respective treatments were correlated with decreases in average surface energy of hair fibers obtained from the corresponding tresses.Experimental results indicate that the average surface energy of hair fibers treated with conditioners decreases and the hydrophobicity of the hair surface increases, the results correlate well with the reduction in combing forces after respective treatments. This research work provides a new methodology to evaluate/screen conditioning performance of hair care ingredients and formulations for development of better products. PMID:21635842

  3. Androgen receptor co-activator Hic-5/ARA55 as a molecular regulator of androgen sensitivity in dermal papilla cells of human hair follicles.

    PubMed

    Inui, Shigeki; Fukuzato, Yoko; Nakajima, Takeshi; Kurata, Sotaro; Itami, Satoshi

    2007-10-01

    Androgen site-specifically affects human hair growth after puberty through androgen receptors in the dermal papilla, which transactivate target genes acting in conjunction with co-activators. To examine the regulation of androgen sensitivity in hair follicles, we focused on androgen receptor co-activator Hic-5/ARA55. Its interaction with transfected androgen receptor in beard dermal papilla cells was confirmed with mammalian two-hybrid assays. The semiquantitative reverse transcriptase-polymerase chain reaction showed that Hic-5/ARA55 mRNA expression was high in dermal papilla cells from the beard and bald frontal scalp but low in cells from the occipital scalp. To determine whether Hic-5/ARA55 mRNA level correlates with its endogenous activity, we studied the effect of dominant negative Hic-5/ARA55 on transfected androgen receptor transactivation induced by R1881 using mouse mammary tumor virus-luciferase assays. We found that it suppressed the transactivation by 64.5 and 71.4% in dermal papilla cells from the beard and bald frontal scalp, respectively, whereas it showed no significant effect in cells from the occipital scalp. Our findings suggest that Hic-5/ARA55 is a molecular regulator for androgen sensitivity in human hair follicles. PMID:17508020

  4. Hair cosmetics: an overview.

    PubMed

    Gavazzoni Dias, Maria Fernanda Reis

    2015-01-01

    Hair cosmetics are an important tool that helps to increase patient's adhesion to alopecia and scalp treatments. This article reviews the formulations and the mode of action of hair cosmetics: Shampoos, conditioners, hair straightening products, hair dyes and henna; regarding their prescription and safetiness. The dermatologist's knowledge of hair care products, their use, and their possible side effects can extend to an understanding of cosmetic resources and help dermatologists to better treat hair and scalp conditions according to the diversity of hair types and ethnicity. PMID:25878443

  5. Hair Cosmetics: An Overview

    PubMed Central

    Gavazzoni Dias, Maria Fernanda Reis

    2015-01-01

    Hair cosmetics are an important tool that helps to increase patient's adhesion to alopecia and scalp treatments. This article reviews the formulations and the mode of action of hair cosmetics: Shampoos, conditioners, hair straightening products, hair dyes and henna; regarding their prescription and safetiness. The dermatologist's knowledge of hair care products, their use, and their possible side effects can extend to an understanding of cosmetic resources and help dermatologists to better treat hair and scalp conditions according to the diversity of hair types and ethnicity. PMID:25878443

  6. Fusion of the endoplasmic reticulum and mitochondrial outer membrane in rats brown adipose tissue: activation of thermogenesis by Ca2+.

    PubMed

    de Meis, Leopoldo; Ketzer, Luisa A; da Costa, Rodrigo Madeiro; de Andrade, Ivone Rosa; Benchimol, Marlene

    2010-01-01

    Brown adipose tissue (BAT) mitochondria thermogenesis is regulated by uncoupling protein 1 (UCP 1), GDP and fatty acids. In this report, we observed fusion of the endoplasmic reticulum (ER) membrane with the mitochondrial outer membrane of rats BAT. Ca(2+)-ATPase (SERCA 1) was identified by immunoelectron microscopy in both ER and mitochondria. This finding led us to test the Ca(2+) effect in BAT mitochondria thermogenesis. We found that Ca(2+) increased the rate of respiration and heat production measured with a microcalorimeter both in coupled and uncoupled mitochondria, but had no effect on the rate of ATP synthesis. The Ca(2+) concentration needed for half-maximal activation varied between 0.08 and 0.11 microM. The activation of respiration was less pronounced than that of heat production. Heat production and ATP synthesis were inhibited by rotenone and KCN. Liver mitochondria have no UCP1 and during respiration synthesize a large amount of ATP, produce little heat, GDP had no effect on mitochondria coupling, Ca(2+) strongly inhibited ATP synthesis and had little or no effect on the small amount of heat released. These finding indicate that Ca(2+) activation of thermogenesis may be a specific feature of BAT mitochondria not found in other mitochondria such as liver. PMID:20209153

  7. Hair loss in women.

    PubMed

    Harfmann, Katya L; Bechtel, Mark A

    2015-03-01

    Hair loss is a common cause of morbidity for many women. As a key member of the woman's health care team, the obstetrician/gynecologist may be the first person to evaluate the complaint of hair loss. Common types of nonscarring hair loss, including female pattern hair loss and telogen effluvium, may be diagnosed and managed by the obstetrician/gynecologist. A systematic approach to diagnosis and management of these common forms of hair loss is presented. PMID:25517757

  8. Mesenchymal-epithelial interactions during hair follicle morphogenesis and cycling

    PubMed Central

    Sennett, Rachel; Rendl, Michael

    2012-01-01

    Embryonic hair follicle induction and formation are regulated by mesenchymal-epithelial interactions between specialized dermal cells and epidermal stem cells that switch to a hair fate. Similarly, during postnatal hair growth, communication between mesenchymal dermal papilla cells and surrounding epithelial matrix cells coordinates hair shaft production. Adult hair follicle regeneration in the hair cycle again is thought to be controlled by activating signals originating from the mesenchymal compartment and acting on hair follicle stem cells. Although many signaling pathways are implicated in hair follicle formation and growth, the precise nature, timing, and intersection of these inductive and regulatory signals remains elusive. The goal of this review is to summarize our current understanding and to discuss recent new insights into mesenchymal-epithelial interactions during hair follicle morphogenesis and cycling. PMID:22960356

  9. 77 FR 5039 - Accommodation Service Provided on Vessels Engaged in U.S. Outer Continental Shelf Activities

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-01

    ... SECURITY Coast Guard Accommodation Service Provided on Vessels Engaged in U.S. Outer Continental Shelf... providing accommodation service on the U.S. Outer Continental Shelf. DATES: Comments and related material... Act notice regarding our public dockets in the January 17, 2008, issue of the Federal Register (73...

  10. Ion beam microanalysis of human hair follicles

    NASA Astrophysics Data System (ADS)

    Kertész, Zs.; Szikszai, Z.; Pelicon, P.; Simčič, J.; Telek, A.; Bíró, T.

    2007-07-01

    Hair follicle is an appendage organ of the skin which is of importance to the survival of mammals and still maintains significance for the human race - not just biologically, but also through cosmetic and commercial considerations. However data on composition of hair follicles are scarce and mostly limited to the hair shaft. In this study we provide detailed information on the elemental distribution in human hair follicles in different growth phases (anagen and catagen) using a scanning proton microprobe. The analysis of skin samples obtained from human adults undergoing plastic surgery and of organ-cultured human hair follicles may yield a new insight into the function, development and cyclic activity of the hair follicle.

  11. Lithium chloride promotes the odontoblast differentiation of hair follicle neural crest cells by activating Wnt/β-catenin signaling.

    PubMed

    Shan, Tengfei; Zhou, Cheng; Yang, Rong; Yan, Fei; Zhang, Ping; Fu, Yu; Jiang, Hongbing

    2015-01-01

    The Wnt/β-catenin signalling pathway contributes to the maintenance of pluripotency and partial reprogramming of stem cells. Postnatal neural crest cells (NCCs) can differentiate into odontoblast-like cells due to their multi-potential property, but further endeavors need to be made to promote odontogenic differentiation of hair follicle neural crest cells (hfNCCs). This study investigated whether the Wnt pathway activator lithium chloride (LiCl) promotes odontoblast differentiation of hfNCCs. Change of proliferation, β-catenin and pluripotency markers of hfNCCs were examined after treatment with LiCl. An in vitro odontoblast differentiation model of hfNCCs was built using dental cell conditioned media (DC-CM). The effects of LiCl on odontoblast differentiation of hfNCCs showed that proliferation and expression of β-catenin in the cytosolic and nuclear compartments were increased in the LiCl-treated hfNCCs, and the pluripotency marks, Oct4, Klf4, Sox2 and Nanog, were more highly expressed in the LiCl-treated group than in the control group. The odontoblast markers such as DSP, DMP1 and Runx2, could be detected in hfNCCs induced by DC-CM, but in LiCl -treated group all three markers had stronger expression. Expression of β-catenin in the nuclear of LiCl-treated hfNCCs induced by DC-CM was higher than in the other groups. The data indicate that the Wnt pathway activator LiCl can promote proliferation and odontoblast differentiation of hfNCCs, and chemical approaches are of benefit in obtaining more desirable seed cell types for cell-based therapies. PMID:25044369

  12. Cytotoxic and Inflammatory Responses Induced by Outer Membrane Vesicle-Associated Biologically Active Proteases from Vibrio cholerae.

    PubMed

    Mondal, Ayan; Tapader, Rima; Chatterjee, Nabendu Sekhar; Ghosh, Amit; Sinha, Ritam; Koley, Hemanta; Saha, Dhira Rani; Chakrabarti, Manoj K; Wai, Sun Nyunt; Pal, Amit

    2016-05-01

    Proteases in Vibrio cholerae have been shown to play a role in its pathogenesis. V. cholerae secretes Zn-dependent hemagglutinin protease (HAP) and calcium-dependent trypsin-like serine protease (VesC) by using the type II secretion system (TIISS). Our present studies demonstrated that these proteases are also secreted in association with outer membrane vesicles (OMVs) and transported to human intestinal epithelial cells in an active form. OMV-associated HAP induces dose-dependent apoptosis in Int407 cells and an enterotoxic response in the mouse ileal loop (MIL) assay, whereas OMV-associated VesC showed a hemorrhagic fluid response in the MIL assay, necrosis in Int407 cells, and an increased interleukin-8 (IL-8) response in T84 cells, which were significantly reduced in OMVs from VesC mutant strain. Our results also showed that serine protease VesC plays a role in intestinal colonization of V. cholerae strains in adult mice. In conclusion, our study shows that V. cholerae OMVs secrete biologically active proteases which may play a role in cytotoxic and inflammatory responses. PMID:26930702

  13. Foxp1 Regulates the Proliferation of Hair Follicle Stem Cells in Response to Oxidative Stress during Hair Cycling

    PubMed Central

    Zhao, Jianzhi; Li, Hanjun; Zhou, Rujiang; Ma, Gang; Dekker, Joseph D.; Tucker, Haley O.; Yao, Zhengju; Guo, Xizhi

    2015-01-01

    Hair follicle stem cells (HFSCs) in the bugle circularly generate outer root sheath (ORS) through linear proliferation within limited cycles during anagen phases. However, the mechanisms controlling the pace of HFSC proliferation remain unclear. Here we revealed that Foxp1, a transcriptional factor, was dynamically relocated from the nucleus to the cytoplasm of HFSCs in phase transitions from anagen to catagen, coupled with the rise of oxidative stress. Mass spectrum analyses revealed that the S468 phosphorylation of Foxp1 protein was responsive to oxidative stress and affected its nucleocytoplasmic translocation. Foxp1 deficiency in hair follicles led to compromised ROS accrual and increased HFSC proliferation. And more, NAC treatment profoundly elongated the anagen duration and HFSC proliferation in Foxp1-deficient background. Molecularly, Foxp1 augmented ROS levels through suppression of Trx1-mediated reductive function, thereafter imposing the cell cycle arrest by modulating the activity of p19/p53 pathway. Our findings identify a novel role for Foxp1 in controlling HFSC proliferation with cellular dynamic location in response to oxidative stress during hair cycling. PMID:26171970

  14. PagP Activation in the Outer Membrane Triggers R3 Core Oligosaccharide Truncation in the Cytoplasm of Escherichia coli O157:H7

    PubMed Central

    Smith, Abigail E.; Kim, Sang-Hyun; Liu, Feng; Jia, Wenyi; Vinogradov, Evgeny; Gyles, Carlton L.; Bishop, Russell E.

    2016-01-01

    The Escherichia coli outer membrane phospholipid:lipid A palmitoyltransferase PagP is normally a latent enzyme, but it can be directly activated in outer membranes by lipid redistribution associated with a breach in the permeability barrier. We now demonstrate that a lipid A myristate deficiency in an E. coli O157:H7 msbB mutant constitutively activates PagP in outer membranes. The lipid A myristate deficiency is associated with hydrophobic antibiotic sensitivity and, unexpectedly, with serum sensitivity, which resulted from O-antigen polysaccharide absence due to a cytoplasmically determined truncation at the first outer core glucose unit of the R3 core oligosaccharide. Mutational inactivation of pagP in the myristate-deficient lipid A background aggravated the hydrophobic antibiotic sensitivity as a result of losing a partially compensatory increase in lipid A palmitoylation while simultaneously restoring serum resistance and O-antigen attachment to intact lipopolysaccharide. Complementation with either wild-type pagP or catalytically inactive pagPSer77Ala alleles restored the R3 core truncation. However, the intact lipopolysaccharide was preserved after complementation with an internal deletion pagPΔ5–14 allele, which mostly eliminates a periplasmic amphipathic α-helical domain but fully supports cell surface lipid A palmitoylation. Our findings indicate that activation of PagP not only triggers lipid A palmitoylation in the outer membrane but also separately truncates the R3 core oligosaccharide in the cytoplasm. We discuss the implication that PagP might function as an apical sensory transducer, which can be activated by a breach in the outer membrane permeability barrier. PMID:18070877

  15. New trichoscopy findings in trichotillomania: flame hairs, V-sign, hook hairs, hair powder, tulip hairs.

    PubMed

    Rakowska, Adriana; Slowinska, Monika; Olszewska, Malgorzata; Rudnicka, Lidia

    2014-05-01

    Differential diagnosis of trichotillomania is often difficult in clinical practice. Trichoscopy (hair and scalp dermoscopy) effectively supports differential diagnosis of various hair and scalp diseases. The aim of this study was to assess the usefulness of trichoscopy in diagnosing trichotillomania. The study included 370 patients (44 with trichotillomania, 314 with alopecia areata and 12 with tinea capitis). Statistical analysis revealed that the main and most characteristic trichoscopic findings of trichotillomania are: irregularly broken hairs (44/44; 100% of patients), v-sign (24/44; 57%), flame hairs (11/44; 25%), hair powder (7/44; 16%) and coiled hairs (17/44; 39%). Flame hairs, v-sign, tulip hairs, and hair powder were newly identified in this study. In conclusion, we describe here specific trichoscopy features, which may be applied in quick, non-invasive, in-office differential diagnosis of trichotillomania. PMID:24096547

  16. Functional maturation of the exocytotic machinery at gerbil hair cell ribbon synapses

    PubMed Central

    Johnson, Stuart L; Franz, Christoph; Knipper, Marlies; Marcotti, Walter

    2009-01-01

    Auditory afferent fibre activity in mammals relies on neurotransmission at hair cell ribbon synapses. Developmental changes in the Ca2+ sensitivity of the synaptic machinery allow inner hair cells (IHCs), the primary auditory receptors, to encode Ca2+ action potentials (APs) during pre-hearing stages and graded receptor potentials in adult animals. However, little is known about the time course of these changes or whether the kinetic properties of exocytosis differ as a function of IHC position along the immature cochlea. Furthermore, the role of afferent transmission in outer hair cells (OHCs) is not understood. Calcium currents and exocytosis (measured as membrane capacitance changes: ΔCm) were measured with whole-cell recordings from immature gerbil hair cells using near-physiological conditions. The kinetics, vesicle pool depletion and Ca2+ coupling of exocytosis were similar in apical and basal immature IHCs. This could indicate that possible differences in AP activity along the immature cochlea do not require synaptic specialization. Neurotransmission in IHCs became mature from postnatal day 20 (P20), although changes in its Ca2+ dependence occurred at P9–P12 in basal and P12–P15 in apical cells. OHCs showed a smaller ΔCm than IHCs that was reflected by fewer active zones in OHCs. Otoferlin, the proposed Ca2+ sensor in cochlear hair cells, was similarly distributed in both cell types despite the high-order exocytotic Ca2+ dependence in IHCs and the near-linear relation in OHCs. The results presented here provide a comprehensive study of the function and development of hair cell ribbon synapses. PMID:19237422

  17. Dkk4 and Eda regulate distinctive developmental mechanisms for subtypes of mouse hair.

    PubMed

    Cui, Chang-Yi; Kunisada, Makoto; Piao, Yulan; Childress, Victoria; Ko, Minoru S H; Schlessinger, David

    2010-01-01

    The mouse hair coat comprises protective "primary" and thermo-regulatory "secondary" hairs. Primary hair formation is ectodysplasin (Eda) dependent, but it has been puzzling that Tabby (Eda(-/y)) mice still make secondary hair. We report that Dickkopf 4 (Dkk4), a Wnt antagonist, affects an auxiliary pathway for Eda-independent development of secondary hair. A Dkk4 transgene in wild-type mice had no effect on primary hair, but secondary hairs were severely malformed. Dkk4 action on secondary hair was further demonstrated when the transgene was introduced into Tabby mice: the usual secondary follicle induction was completely blocked. The Dkk4-regulated secondary hair pathway, like the Eda-dependent primary hair pathway, is further mediated by selective activation of Shh. The results thus reveal two complex molecular pathways that distinctly regulate subtype-based morphogenesis of hair follicles, and provide a resolution for the longstanding puzzle of hair formation in Tabby mice lacking Eda. PMID:20386733

  18. Disrupted hair follicle activity in cattle grazing endophyte-infected tall fescue in the summer insulates core body temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ergot alkaloids produced by an endophyte (Neotyphodium coenophialum) that infects most plants of tall fescue (Lolium arundinaceum) causes cattle to have rough hair coats during the summer and persistent vascular constriction that impedes heat dissipation via blood flow to peripheral tissues. Experi...

  19. The Nicotinic Receptor of Cochlear Hair Cells: A Possible Pharmacotherapeutic Target?

    PubMed Central

    Elgoyhen, Ana Belén; Katz, Eleonora; Fuchs, Paul A.

    2009-01-01

    Mechanosensory hair cells of the organ of Corti transmit information regarding sound to the central nervous system by way of peripheral afferent neurons. In return, the central nervous system provides feedback and modulates the afferent stream of information through efferent neurons. The medial olivocochlear efferent system makes direct synaptic contacts with outer hair cells and inhibits amplification brought about by the active mechanical process inherent to these cells. This feedback system offers the potential to improve the detection of signals in background noise, to selectively attend to particular signals, and to protect the periphery from damage caused by overly loud sounds. Acetylcholine released at the synapse between efferent terminals and outer hair cells activates a peculiar nicotinic cholinergic receptor subtype, the α9α10 receptor. At present no pharmacotherapeutic approaches have been designed that target this cholinergic receptor to treat pathologies of the auditory system. The potential use of α9α10 selective drugs in conditions such as noise-induced hearing loss, tinnitus and auditory processing disorders is discussed. PMID:19481062

  20. Building a hair: tip growth in Arabidopsis thaliana root hairs.

    PubMed Central

    Carol, Rachel J; Dolan, Liam

    2002-01-01

    The Arabidopsis thaliana root hair is used as a model for studying tip growth in plants. We review recent advances, made using physiological and genetic approaches, which give rise to different, yet compatible, current views of the establishment and maintenance of tip growth in epidermal cells. For example, an active calcium influx channel localized at the tip of Arabidopsis root hairs has been identified by patch-clamp measurements. Actin has been visualized in vivo in Arabidopsis root hairs by using a green-fluorescent-protein-talin reporter and shown to form a dense mesh in the apex of the growing tip. The kojak gene, which encodes a protein similar to the catalytic subunit of cellulose synthase, is needed in the first stages of hair growth. A role for LRX1, a leucine-rich repeat extensin, in determining the morphology of the cell wall of root hairs has been established using reverse genetics. The new information can be integrated into a general and more advanced view of how these specialized plant cells grow. PMID:12079677

  1. Conventional gas resources of the Gulf of Mexico Outer Continental Shelf - past experience, current activities, future potential

    SciTech Connect

    Lore, G.L. )

    1993-01-01

    Original recoverable proved reserves of hydrocarbons in the 819 fields discovered through 1991 on the Gulf of Mexico Outer Continental Shelf (GOM OCS) are estimated to be 10.74 billion barrels of oil (Bbo) and 130.5 trillion cubic feet of natural gas (Tcfg). Eighty-one of these fields have been depleted and abandoned. Remaining reserves recoverable from the 738 active fields have been estimated to be 2.33 Bbo and 32.0 Tcfg. An additional 70 active fields have not been sufficiently developed to warrant consideration as proved. The GOM OCS is primarily a gas-prone province. Of the 819 proved fields, 676 are classified as gas fields. Cumulative production through 1991 was 8.41 Bbo and 98.5 Tcfg. On an energy-equivalent basis this production equates to nearly 68 percent natural gas. In recent years the area has contributed about 10 percent of the Nation's total domestic oil production and 22 to 25 percent of the gas. Even though three-quarters of the estimated original recoverable proved gas reserves have been produced, the GOM OCS, as the Nation's premier natural-gas-producing province, will continue to have a pivotal role in determining our future gas supply. Historically, oil and gas exploration and development have gradually progressed seaward into the deeper waters of the Gulf of Mexico. The average size of fields discovered has decreased steadily over time, and the exploration effort required for each incremental reserve addition has increased. Assessments of potential undiscovered, economically recoverable conventional hydrocarbon resources on the GOM OCS are highly sensitive to assumptions concerning future cost-price relationships. These assessments suggest that as much gas may still be undiscovered as has already been discovered on the GOM OCS. 13 refs., 6 figs., 3 tabs.

  2. Replacing facial hair.

    PubMed

    Straub, Paul M

    2008-11-01

    The face is the second most common area for hair transplantation after the scalp. Areas that are transplanted include eyebrows, eyelashes, moustaches, beards, temples and temporal points, as well as scars either traumatic or the side effect of cosmetic procedures such as rhytidectomies or brow lifts. The hair is harvested from the same area as the hair that is transplanted to the head. For this reason, it grows longer than nongrafted facial hair and must be trimmed regularly. Occasionally, hair lower in the neck region is harvested, which is finer than occipital hair; however, because of movement in the neck area, the scars are often larger. Body hair has been suggested as donor hair but is not recommended because it spends as much as 85% of its time in the telogen phase. PMID:19034820

  3. Hitchhiking women's hair color.

    PubMed

    Guéguen, Nicolas; Lamy, Lubomir

    2009-12-01

    To test the effect of women's hair color on the frequency of offering help, male (n = 1,508) and female (n = 892) French motorists were tested in a hitchhiking situation. Five 20- to 22- yr.-old female confederates wore a wig with blonde, brown, or black hair. Each confederate was instructed to stand by the side of a road frequented by hitchhikers and hold out her thumb to catch a ride. Blonde hair, compared with brown hair or black hair, was associated with a small but significantly larger number of male drivers who stopped to offer a ride (18 vs 14%). No difference was found for those with brown and black hair (14 and 13%, respectively). No effect of hair color was found for female drivers who stopped. The greater attractiveness associated with blonde hair for women appears to explain these data. PMID:20178293

  4. Hair straightener poisoning

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002706.htm Hair straightener poisoning To use the sharing features on this page, please enable JavaScript. Hair straightener poisoning occurs when someone swallows products that ...

  5. Skin, Hair, and Nails

    MedlinePlus

    ... special types of cells: Melanocytes produce melanin, the pigment that gives skin its color. All people have ... the epidermis). Hair also contains a yellow-red pigment; people who have blonde or red hair have ...

  6. Study of colouring effect of herbal hair formulations on graying hair

    PubMed Central

    Singh, Vijender; Ali, Mohammed; Upadhyay, Sukirti

    2015-01-01

    Objective: To screen the hair colouring properties of hair colorants/ herbal hair colouring formulations. Materials and Methods: The dried aqueous herbal extracts of Gudhal leaves (Hibiscus rosa-sinensis), Jatamansi rhizome (Nardostachys jatamansi), Kuth roots (Saussurea lappa), Kattha (Acacia catechu), Amla dried fruit (Embelica officinalis), were prepared. Coffee powder (Coffea arabica) and Henna powder (Lowsonia inermis) were taken in the form of powder (# 40). Fourteen herbal hair colorants were prepared from these dried aqueous herbal extracts and powders. Activities of hair colorants were observed on sheep wool fibers. On the basis of the above observation six hair colorants were selected. These six formulations were taken for trials on human beings. Observation: The formulation coded HD-3 gave maximum colouring effect on sheep wool fibers as well as on human beings and percentage of acceptance among the volunteers were in the following order: HD- 3 > HD- 4 > HD-1 > HD-13 > HD-14 > HD-11. Results and Discussion: The remarkable results were obtained from five herbal hair colorants, viz., HD-1, HD- 3, HD- 4, HD-13 and HD-14 on sheep wool fibers and human beings. Formulation HD-3, having gudhal, jatamansi, kuth, kattha, amla, coffee and henna, was the maximum accepted formulation and suggested that these herbs in combination acts synergistically in hair colouring action. It also concluded that jatamansi, present in different hair colorants, was responsible to provide maximum blackening on hair PMID:26130937

  7. Renaturation of Recombinant Treponema pallidum Rare Outer Membrane Protein 1 into a Trimeric, Hydrophobic, and Porin-Active Conformation

    PubMed Central

    Zhang, Hongwei H.; Blanco, David R.; Exner, Maurice M.; Shang, Ellen S.; Champion, Cheryl I.; Phillips, Martin L.; Miller, James N.; Lovett, Michael A.

    1999-01-01

    We have previously observed that while native Treponema pallidum rare outer membrane protein 1 (Tromp1) is hydrophobic and has porin activity, recombinant forms of Tromp1 do not possess these properties. In this study we show that these properties are determined by conformation and can be replicated by proper renaturation of recombinant Tromp1. Native Tromp1, but not the 47-kDa lipoprotein, extracted from whole organisms by using Triton X-114, was found to lose hydrophobicity after treatment in 8 M urea, indicating that Tromp1’s hydrophobicity is conformation dependent. Native Tromp1 was purified from 0.1% Triton X-100 extracts of whole organisms by fast-performance liquid chromatography (FPLC) and shown to have porin activity in planar lipid bilayers. Cross-linking studies of purified native Tromp1 with an 11 Å cross-linking agent showed oligomeric forms consistent with dimers and trimers. For renaturation studies of recombinant Tromp1 (rTromp1), a 31,109-Da signal-less construct was expressed in Escherichia coli and purified by FPLC. FPLC-purified rTromp1 was denatured in 8 M urea and then renatured in the presence of 0.5% Zwittergent 3,14 during dialysis to remove the urea. Renatured rTromp1 was passed through a Sephacryl S-300 gel exclusion column previously calibrated with known molecular weight standards. While all nonrenatured rTromp1 eluted from the column at approximately the position of the carbonic anhydrase protein standard (29 kDa), all renatured rTromp1 eluted at the position of the phosphorylase b protein standard (97 kDa), suggesting a trimeric conformation. Trimerization was confirmed by using an 11 Å cross-linking agent which showed both dimers and trimers similar to that of native Tromp1. Triton X-114 phase separations showed that all of renatured rTromp1, but none of nonrenatured rTromp1, phase separated exclusively into the hydrophobic detergent phase, similar to native Tromp1. Circular dichroism of nonrenatured and renatured rTromp1

  8. Hair transplantation update.

    PubMed

    Rogers, Nicole E

    2015-06-01

    Contemporary hair transplant surgery offers results that are natural and undetectable. It is an excellent treatment option for male and female pattern hair loss. Patients are encouraged to also use medical therapy to help protect their surgical results and prevent ongoing thinning of the surrounding hairs. The two major techniques of donor elliptical harvesting and follicular unit extraction are discussed here. PMID:26176286

  9. Insensitivity of the Audiogram to Carboplatin Induced Inner hair cell loss in Chinchillas

    PubMed Central

    Lobarinas, Edward; Salvi, Richard; Ding, Dalian

    2013-01-01

    Noise trauma, aging, and ototoxicity preferentially damage the outer hair cells of the inner ear, leading to increased hearing thresholds and poorer frequency resolution. Whereas outer hair cells make synaptic connections with less than 10% of afferent auditory nerve fibers (type-II), inner hair cells make connections with over 90% of afferents (type-I). Despite these extensive connections, little is known about how selective inner hair cell loss impacts hearing. In chinchillas, moderate to high doses of the anticancer compound carboplatin produce selective inner hair cell and type-I afferent loss with little to no effect on outer hair cells. To determine the effects of carboplatin-induced inner hair cell loss on the most widely used clinical measure of hearing, the audiogram, pure-tone thresholds were determined behaviorally before and after 75 mg/kg carboplatin. Following carboplatin treatment, small effects on audiometric thresholds were observed even with extensive inner hair cell losses that exceed 80%. These results suggest that conventional audiometry is insensitive to inner hair cell loss and that only small populations of inner hair cells appear to be necessary for detecting tonal stimuli in a quiet background. PMID:23566980

  10. Deficiency in nucleotide excision repair family gene activity, especially ERCC3, is associated with non-pigmented hair fiber growth.

    PubMed

    Yu, Mei; Bell, Robert H; Ho, Maggie M; Leung, Gigi; Haegert, Anne; Carr, Nicholas; Shapiro, Jerry; McElwee, Kevin J

    2012-01-01

    We conducted a microarray study to discover gene expression patterns associated with a lack of melanogenesis in non-pigmented hair follicles (HF) by microarray. Pigmented and non-pigmented HFs were collected and micro-dissected into the hair bulb (HB) and the upper hair sheaths (HS) including the bulge region. In comparison to pigmented HS and HBs, nucleotide excision repair (NER) family genes ERCC1, ERCC2, ERCC3, ERCC4, ERCC5, ERCC6, XPA, NTPBP, HCNP, DDB2 and POLH exhibited statistically significantly lower expression in non- pigmented HS and HBs. Quantitative PCR verified microarray data and identified ERCC3 as highly differentially expressed. Immunohistochemistry confirmed ERCC3 expression in HF melanocytes. A reduction in ERCC3 by siRNA interference in human melanocytes in vitro reduced their tyrosinase production ability. Our results suggest that loss of NER gene function is associated with a loss of melanin production capacity. This may be due to reduced gene transcription and/or reduced DNA repair in melanocytes which may eventually lead to cell death. These results provide novel information with regard to melanogenesis and its regulation. PMID:22615732

  11. Evidence for biological shaping of hair ice

    NASA Astrophysics Data System (ADS)

    Hofmann, D.; Preuss, G.; Mätzler, C.

    2015-04-01

    An unusual ice type, called hair ice, grows on the surface of dead wood of broad-leaf trees at temperatures slightly below 0 °C. We describe this phenomenon and present physical, chemical, and biological investigations to gain insight in the properties and processes related to hair ice. Tests revealed that the biological activity of a winter-active fungus is required in the wood for enabling the growth of hair ice. We confirmed the fungus hypothesis originally suggested by Wegener (1918) by reproducing hair ice on wood samples. Treatment by heat and fungicide, respectively, suppresses the formation of hair ice. Fruiting bodies of Asco- and Basidiomycota are identified on hair-ice carrying wood. One species, Exidiopsis effusa (Ee), has been present on all investigated samples. Both hair-ice producing wood samples and those with killed fungus show essentially the same temperature variation, indicating that the heat produced by fungal metabolism is very small, that the freezing rate is not influenced by the fungus activity and that ice segregation is the common mechanism of ice growth at the wood surface. The fungus plays the role of shaping the ice hairs and to prevent them from recrystallisation. Melted hair ice indicates the presence of organic matter. Chemical analyses show a complex mixture of several thousand CHO(N,S)-compounds similar to fulvic acids in dissolved organic matter (DOM). The evaluation reveals decomposed lignin as the main constituent. Further work is needed to clarify its role in hair-ice growth and to identify the recrystallisation inhibitor.

  12. Evidence for biological shaping of hair ice

    NASA Astrophysics Data System (ADS)

    Hofmann, D.; Preuss, G.; Mätzler, C.

    2015-07-01

    An unusual ice type, called hair ice, grows on the surface of dead wood of broad-leaf trees at temperatures slightly below 0 °C. We describe this phenomenon and present physical, chemical, and biological investigations to gain insight in the properties and processes related to hair ice. Tests revealed that the biological activity of a winter-active fungus is required in the wood for enabling the growth of hair ice. We confirmed the fungus hypothesis originally suggested by Wegener (1918) by reproducing hair ice on wood samples. Treatment by heat and fungicide suppresses the formation of hair ice. Fruiting bodies of Asco- and Basidiomycota are identified on hair-ice-carrying wood. One species, Exidiopsis effusa (Ee), was present on all investigated samples. Both hair-ice-producing wood samples and those with killed fungus show essentially the same temperature variation, indicating that the heat produced by fungal metabolism is very small, that the freezing rate is not influenced by the fungus activity, and that ice segregation is the common mechanism of ice growth on the wood surface. The fungus plays the role of shaping the ice hairs and preventing them from recrystallisation. Melted hair ice indicates the presence of organic matter. Chemical analyses show a complex mixture of several thousand CHO(N,S) compounds similar to fulvic acids in dissolved organic matter (DOM). The evaluation reveals decomposed lignin as being the main constituent. Further work is needed to clarify its role in hair-ice growth and to identify the recrystallisation inhibitor.

  13. Hair loss in children.

    PubMed

    Alves, Rubina; Grimalt, Ramon

    2015-01-01

    Hair diseases represent frequent complaints in dermatology clinics, and they can be caused by a number of conditions reflected by specific diagnoses. Hair loss is not uncommon in the pediatric group, but its patterns in this group are different from those seen in adults. Additionally, in children, these disorders can have psychological effects that can interfere with growth and development. Hair is easily accessible for examination, and dermatologists are in the enviable situation of being able to study many disorders using simple diagnostic techniques. To fully understand hair loss during childhood, a basic comprehension of normal hair growth is necessary. Knowledge of the normal range and variation observed in the hair of children further enhances its assessment. This chapter has been written in an attempt to facilitate the diagnostic process during daily practice by helping to distinguish between acquired and congenital hair diseases. It can sometimes be difficult to differentiate between abnormality and normality in neonatal hair aspects. Management of hair disorders can be quite a daunting task for the attending physician and mandates a holistic approach to the patient. Some hair disturbances have no effective treatment, and for others, no single treatment is 100% successful. If no effective treatment for a hair loss disease exists, a cosmetic approach is important. PMID:26370644

  14. [Hormones and hair growth].

    PubMed

    Trüeb, R M

    2010-06-01

    With respect to the relationship between hormones and hair growth, the role of androgens for androgenetic alopecia (AGA) and hirsutism is best acknowledged. Accordingly, therapeutic strategies that intervene in androgen metabolism have been successfully developed for treatment of these conditions. Clinical observations of hair conditions involving hormones beyond the androgen horizon have determined their role in regulation of hair growth: estrogens, prolactin, thyroid hormone, cortisone, growth hormone (GH), and melatonin. Primary GH resistance is characterized by thin hair, while acromegaly may cause hypertrichosis. Hyperprolactinemia may cause hair loss and hirsutism. Partial synchronization of the hair cycle in anagen during late pregnancy points to an estrogen effect, while aromatase inhibitors cause hair loss. Hair loss in a causal relationship to thyroid disorders is well documented. In contrast to AGA, senescent alopecia affects the hair in a diffuse manner. The question arises, whether the hypothesis that a causal relationship exists between the age-related reduction of circulating hormones and organ function also applies to hair and the aging of hair. PMID:20502852

  15. Targeting the annulus fibrosus of the intervertebral disc: Col1a2-Cre(ER)T mice show specific activity of Cre recombinase in the outer annulus fibrosus.

    PubMed

    Bedore, Jake; Quesnel, Katherine; Quinonez, Diana; Séguin, Cheryle A; Leask, Andrew

    2016-06-01

    Degeneration of the intervertebral disc (IVD) is a major underlying contributor to back pain-the single leading cause of disability worldwide. However, we possess a limited understanding of the etiology underlying IVD degeneration. To date, there are a limited number of mouse models that have been used to target proteins in specific compartments of the IVD to explore their functions in disc development, homeostasis and disease. Furthermore, the majority of reports exploring the composition and function of the outer encapsulating annulus fibrosus (AF) of the IVD have considered it as one tissue, without considering the numerous structural and functional differences existing between the inner and outer AF. In addition, no mouse models have yet been reported that enable specific targeting of genes within the outer AF. In the current report, we discuss these issues and demonstrate the localized activity of Cre recombinase in the IVD of Col1a2-Cre(ER)T;ROSA26mTmG mice possessing a tamoxifen-dependent Cre recombinase driven by a Cola2 promoter and distal enhancer and the mTmG fluorescent reporter. Following tamoxifen injection of 3-week-old Col1a2-Cre(ER)T;ROSA26mTmG mice, we show Cre activity specifically in the outer AF of the IVD, as indicated by expression of the GFP reporter. Thus, Col1a2-Cre(ER)T;ROSA26mTmG mice may prove to be a valuable tool in delineating the function of proteins in this unique compartment of the IVD, and in further exploring the compositional differences between the inner and outer AF in disc homeostasis, aging and disease. PMID:27173473

  16. Activity of carnitine palmitoyltransferase in mitochondrial outer membranes and peroxisomes in digitonin-permeabilized hepatocytes. Selective modulation of mitochondrial enzyme activity by okadaic acid.

    PubMed Central

    Guzmán, M; Geelen, M J

    1992-01-01

    A procedure is described for the rapid measurement of the activity of mitochondrial-outer-membrane carnitine palmitoyltransferase (CPTo) and peroxisomal carnitine palmitoyltransferase (CPTp) in digitonin-permeabilized hepatocytes. CPTo activity was determined as the tetradecylglycidate (TDGA)-sensitive malonyl-CoA-sensitive CPT activity, whereas CPTp activity was monitored as the TDGA-insensitive malonyl-CoA-sensitive CPT activity. Under these experimental conditions, the respective contributions of CPTo and CPTp to total hepatocellular malonyl-CoA-sensitive CPT activity were 74.6 and 25.4%, which correlated well with the values of 76.9 and 23.1% for the respective contributions of the mitochondrial and the peroxisomal compartment to total hepatocellular palmitate oxidation. The sensitivity of CPTo to inhibition by malonyl-CoA was very similar to that of CPTp; thus 50% inhibition of CPTo and CPTp activities was achieved with malonyl-CoA concentrations of 2.6 +/- 0.5 and 3.0 +/- 0.4 microM respectively. Short-term incubation of hepatocytes with the phosphatase inhibitor okadaic acid (i) increased the activity of CPTo and the rate of mitochondrial palmitate oxidation, (ii) decreased the affinity of CPTo for palmitoyl-CoA substrate, and (iii) decreased the sensitivity of CPTo to inhibition by malonyl-CoA. By contrast, neither the properties of CPTp nor the rate of peroxisomal palmitate oxidation were changed upon incubation of cells with okadaic acid. Results indicate therefore that CPTo, but not CPTp, may be regulated by a mechanism of phosphorylation/dephosphorylation. The physiological relevance of these findings is discussed. PMID:1332675

  17. Chemical processing and shampooing impact cortisol measured in human hair

    PubMed Central

    Hoffman, M. Camille; Karban, Laura V.; Benitez, Patrick; Goodteacher, Angela; Laudenslager, Mark L.

    2015-01-01

    Purpose The assessment of cortisol in hair has gained popularity as a means to measure retrospective hypothalamic-pituitary-adrenal activity in a number of species; however, cortisol levels from human hair subjected to typical chemicals for cosmetic or hygienic purposes may be altered by the chemicals used. The purposed of this study was to determine if exposure of hair to chemical processing or shampooing impacts cortisol values. Methods Human hair not exposed to prior chemical processing was cut from the posterior vertex region of the head of 106 human subjects as close to the scalp as possible. The hair sample was divided into 4-6 full-length clusters depending on quantity of hair available. Each hair sample was processed for baseline (native) cortisol and remaining clusters were exposed to five standard chemical hair treatments (Experiment 1) or were shampooed 15 or 30 times (Experiment 2). Hair was ground and cortisol levels were determined by enzyme immunoassay (EIA). Comparisons were made between native hair and processed hair using paired t-tests and Pearson correlation. Results Hair cortisol as assessed by EIA was significantly altered by chemical processing but in somewhat different ways. Exposure to bleach (harshest exposure), demi-perm (least exposure) or 15-30 shampoos resulted in a significant decrease in cortisol level while exposure to varying percentages of peroxides increased cortisol measured. There were no differences in cortisol levels associated with sex, age or tobacco use in the native hair for this particular group. Conclusion Chemical processing and frequent shampooing affect cortisol levels measured in hair. Chemically processed or excessively shampooed hair should be avoided when recruiting subjects for hair cortisol studies. PMID:25090265

  18. Mutations of the Mouse ELMO Domain Containing 1 Gene (Elmod1) Link Small GTPase Signaling to Actin Cytoskeleton Dynamics in Hair Cell Stereocilia

    PubMed Central

    Johnson, Kenneth R.; Longo-Guess, Chantal M.; Gagnon, Leona H.

    2012-01-01

    Stereocilia, the modified microvilli projecting from the apical surfaces of the sensory hair cells of the inner ear, are essential to the mechanoelectrical transduction process underlying hearing and balance. The actin-filled stereocilia on each hair cell are tethered together by fibrous links to form a highly patterned hair bundle. Although many structural components of hair bundles have been identified, little is known about the signaling mechanisms that regulate their development, morphology, and maintenance. Here, we describe two naturally occurring, allelic mutations that result in hearing and balance deficits in mice, named roundabout (rda) and roundabout-2J (rda2J). Positional cloning identified both as mutations of the mouse ELMO domain containing 1 gene (Elmod1), a poorly characterized gene with no previously reported mutant phenotypes. The rda mutation is a 138 kb deletion that includes exons 1–5 of Elmod1, and rda2J is an intragenic duplication of exons 3–8 of Elmod1. The deafness associated with these mutations is caused by cochlear hair cell dysfunction, as indicated by conspicuous elongations and fusions of inner hair cell stereocilia and progressive degeneration of outer hair cell stereocilia. Mammalian ELMO-family proteins are known to be involved in complexes that activate small GTPases to regulate the actin cytoskeleton during phagocytosis and cell migration. ELMOD1 and ELMOD2 recently were shown to function as GTPase-activating proteins (GAPs) for the Arf family of small G proteins. Our finding connecting ELMOD1 deficiencies with stereocilia dysmorphologies thus establishes a link between the Ras superfamily of small regulatory GTPases and the actin cytoskeleton dynamics of hair cell stereocilia. PMID:22558334

  19. Mutations of the mouse ELMO domain containing 1 gene (Elmod1) link small GTPase signaling to actin cytoskeleton dynamics in hair cell stereocilia.

    PubMed

    Johnson, Kenneth R; Longo-Guess, Chantal M; Gagnon, Leona H

    2012-01-01

    Stereocilia, the modified microvilli projecting from the apical surfaces of the sensory hair cells of the inner ear, are essential to the mechanoelectrical transduction process underlying hearing and balance. The actin-filled stereocilia on each hair cell are tethered together by fibrous links to form a highly patterned hair bundle. Although many structural components of hair bundles have been identified, little is known about the signaling mechanisms that regulate their development, morphology, and maintenance. Here, we describe two naturally occurring, allelic mutations that result in hearing and balance deficits in mice, named roundabout (rda) and roundabout-2J (rda(2J)). Positional cloning identified both as mutations of the mouse ELMO domain containing 1 gene (Elmod1), a poorly characterized gene with no previously reported mutant phenotypes. The rda mutation is a 138 kb deletion that includes exons 1-5 of Elmod1, and rda(2J) is an intragenic duplication of exons 3-8 of Elmod1. The deafness associated with these mutations is caused by cochlear hair cell dysfunction, as indicated by conspicuous elongations and fusions of inner hair cell stereocilia and progressive degeneration of outer hair cell stereocilia. Mammalian ELMO-family proteins are known to be involved in complexes that activate small GTPases to regulate the actin cytoskeleton during phagocytosis and cell migration. ELMOD1 and ELMOD2 recently were shown to function as GTPase-activating proteins (GAPs) for the Arf family of small G proteins. Our finding connecting ELMOD1 deficiencies with stereocilia dysmorphologies thus establishes a link between the Ras superfamily of small regulatory GTPases and the actin cytoskeleton dynamics of hair cell stereocilia. PMID:22558334

  20. Calcium channels in mouse hair cells: function, properties and pharmacology.

    PubMed

    Engel, Jutta; Michna, Marcus; Platzer, Josef; Striessnig, Jörg

    2002-01-01

    Adult inner hair cells (IHCs) possess voltage-activated Ca2+ currents that couple receptor potentials to transmitter release at the afferent synapses. Before the onset of hearing both IHCs and outer hair cells (OHCs) exhibit Ca2+ currents. More than 90% of neonatal hair cell (HC) currents flow through alpha1D Ca2+ channel subunits because they are absent in both IHCs and OHCs from alpha1D-/- mice and residual currents are insensitive to L-type agonists. Since lack of the alpha1D-subunit leads to HC degeneration and profound deafness, class D L-type Ca2+ currents seem to be crucial for the development and functioning of the inner ear. Neonatal HC Ca2+ currents were studied using the whole-cell patch clamp technique. They showed rapid activation, rapid deactivation and very little inactivation. They started activating as negative as -65mV. In contrast to alpha1C-mediated (classical L-type) Ca2+ currents, they showed a rather low sensitivity to various L-type antagonists. 10 microM nifedipine e.g. blocked HC Ca2+ currents by about 40% whereas class C L-type Ca2+ currents are completely blocked by 100nM nifedipine. The L-type channel agonist Bay K 8644 increased the HC Ca2+ current by 100-200% and shifted the IV curve to more negative potentials which is similar to its effects in alpha1C-mediated Ca2+ currents. PMID:11885659

  1. Biomechanical Analysis of a Filiform Mechanosensory Hair Socket of Crickets.

    PubMed

    Joshi, Kanishka; Mian, Ahsan; Miller, John

    2016-08-01

    Filiform mechanosensory hairs of crickets are of great interest to engineers because of the hairs' highly sensitive response to low-velocity air-currents. In this study, we analyze the biomechanical properties of filiform hairs of the cercal sensory system of a common house cricket. The cercal sensory system consists of two antennalike appendages called cerci that are situated at the rear of the cricket's abdomen. Each cercus is covered with 500-750 flow sensitive filiform mechanosensory hairs. Each hair is embedded in a complex viscoelastic socket that acts as a spring and dashpot system and guides the movement of the hair. When a hair deflects due to the drag force induced on its length by a moving air-current, the spiking activity of the neuron that innervates the hair changes and the combined spiking activity of all hairs is extracted by the cercal sensory system. Filiform hairs have been experimentally studied by researchers, though the basis for the hairs' biomechanical characteristics is not fully understood. The socket structure has not been analyzed experimentally or theoretically from a mechanical standpoint, and the characterization that exists is mathematical in nature and only provides a very rudimentary approximation of the socket's spring nature. This study aims to understand and physically characterize the socket's behavior and interaction with the filiform hair by examining hypotheses about the hair and socket biomechanics. A three-dimensional computer-aided design (CAD) model was first created using confocal microscopy images of the hair and socket structure of the cricket, and then finite-element analyses (FEAs) based on the physical conditions that the insect experiences were simulated. The results show that the socket can act like a spring; however, it has two-tier rotational spring constants during pre- and postcontacts of iris and hair bulge due to its constitutive nonstandard geometric shapes. PMID:27322099

  2. Ovine Hair Follicle Stem Cells Derived from Single Vibrissae Reconstitute Haired Skin

    PubMed Central

    Zhang, Huishan; Zhang, Shoubing; Zhao, Huashan; Qiao, Jingqiao; Liu, Shuang; Deng, Zhili; Lei, Xiaohua; Ning, Lina; Cao, Yujing; Zhao, Yong; Duan, Enkui

    2015-01-01

    Hair follicle stem cells (HFSCs) possess fascinating self-renewal capacity and multipotency, which play important roles in mammalian hair growth and skin wound repair. Although HFSCs from other mammalian species have been obtained, the characteristics of ovine HFSCs, as well as the methods to isolate them have not been well addressed. Here, we report an efficient strategy to obtain multipotent ovine HFSCs. Through microdissection and organ culture, we obtained keratinocytes that grew from the bulge area of vibrissa hair follicles, and even abundant keratinocytes were harvested from a single hair follicle. These bulge-derived keratinocytes are highly positive for Krt15, Krt14, Tp63, Krt19 and Itga6; in addition to their strong proliferation abilities in vitro, these keratinocytes formed new epidermis, hair follicles and sebaceous glands in skin reconstitution experiments, showing that these are HFSCs from the bulge outer root sheath. Taken together, we developed an efficient in vitro system to enrich ovine HFSCs, providing enough HFSCs for the investigations about the ovine hair cycle, aiming to promote wool production in the future. PMID:26247934

  3. Expression of decorin throughout the murine hair follicle cycle: hair cycle dependence and anagen phase prolongation.

    PubMed

    Jing, Jing; Wu, Xian-Jie; Li, Yun-Ling; Cai, Sui-Qing; Zheng, Min; Lu, Zhong-Fa

    2014-07-01

    Decorin is a prototypical member of the small leucine-rich proteoglycan (SLRP) family, which is involved in numerous biological processes. The role of decorin, as a representative SLRP, in hair follicle morphogenesis has not been elucidated. We present our initial findings on decorin expression patterns during induced murine hair follicle (HF) cycles. It was found that decorin expression is exclusively restricted to the epidermis, outer root sheath and sebaceous glands during the anagen phase, which correlates with the upregulation of decorin mRNA and protein expression in depilated murine dorsal skin. Furthermore, we used a functional approach to investigate the effects of recombinant human decorin (rhDecorin) via cutaneous injection into HFs at various murine hair cycle stages. The local injection of rhDecorin (100 μg/ml) into the hypodermis of depilated C57BL/6 mice at anagen delayed catagen progression. In contrast, rhDecorin injection during the telogen phase caused the premature onset of anagen, as demonstrated by the assessment of the following parameters: (i) hair shaft length, (ii) follicular bulbar diameter, (iii) hair follicle cycling score and (iv) follicular phase percentage. Taken together, our results suggest that decorin may modulate follicular cycling and morphogenesis. In addition, this study also provides insight into the molecular control mechanisms governing hair follicular epithelial-mesenchymal interactions. PMID:24816226

  4. Identification of Wnt/β-catenin signaling pathway in dermal papilla cells of human scalp hair follicles: TCF4 regulates the proliferation and secretory activity of dermal papilla cell.

    PubMed

    Xiong, Ya; Liu, Yi; Song, Zhiqiang; Hao, Fei; Yang, Xichuan

    2014-01-01

    It is clear that the dermal papilla cell (DPC), which is located at the bottom of the hair follicle, is a special mesenchymal component, and it plays a leading role in regulating hair follicle development and periodic regeneration. Recent studies showed that the Wnt signaling pathway through β-catenin (canonical Wnt signaling pathway) is an essential component in maintaining the hair-inducing activity of the dermal papilla and growth of hair papilla cells. However, the intrinsic pathways and regulating mechanism are largely unknown. In the previous work, we constructed a cDNA subtractive library of DPC and first found that the TCF4 gene, as a key factor of Wnt signaling pathway, was expressed as the upregulated gene of the hair follicle in low-passage DPC. This study was to explore the role of TCF4 in regulating the proliferation and secretory activity of DPC. We constructed a pcDNA3.0-TCF4 expression vector and transfected it into DPC to achieve stable expression by bangosome 2000. Furthermore, we used the method of chemosynthesis to synthesize three pairs of TCF4 siRNA and transfected them into DPC. Meanwhile, we compared the transfection group and non-transfection group. We first proposed that there was expression difference in TCF4 in DPC under different biological condition. This study may have a high impact on the molecular mechanism of follicular lesions and provide a new vision for the treatment of clinic diseases. PMID:24354472

  5. Red ginseng extract promotes the hair growth in cultured human hair follicles.

    PubMed

    Park, Gyeong-Hun; Park, Ki-young; Cho, Hong-il; Lee, Sang-Min; Han, Ji Su; Won, Chong Hyun; Chang, Sung Eun; Lee, Mi Woo; Choi, Jee Ho; Moon, Kee Chan; Shin, Hyoseung; Kang, Yong Jung; Lee, Dong Hun

    2015-03-01

    Ginseng has been shown to promote hair growth in several recent studies. However, its effects on human hair follicles and its mechanisms of action have not been sufficiently elucidated. This study aimed to investigate the hair growth-promoting effects of red ginseng extract (RGE) and its ginsenosides. The proliferative activities of cultured human hair follicles treated with RGE and ginsenoside-Rb1 were assessed using Ki-67 immunostaining. Their effects on isolated human dermal papilla cells (hDPCs) were evaluated using cytotoxicity assays, immunoblot analysis of signaling proteins, and the determination of associated growth factors. We examined the ability of RGE and ginsenosides to protect hair matrix keratinocyte proliferation against dihydrotestosterone (DHT)-induced suppression and their effects on the expression of androgen receptor. The in vivo hair growth-promoting effect of RGE was also investigated in C57BL/6 mice. Both RGE and ginsenoside-Rb1 enhanced the proliferation of hair matrix keratinocytes. hDPCs treated with RGE or ginsenoside-Rb1 exhibited substantial cell proliferation and the associated phosphorylation of ERK and AKT. Moreover, RGE, ginsenoside-Rb1, and ginsenoside-Rg3 abrogated the DHT-induced suppression of hair matrix keratinocyte proliferation and the DHT-induced upregulation of the mRNA expression of androgen receptor in hDPCs. Murine experiments revealed that the subcutaneous injection of 3% RGE resulted in more rapid hair growth than the negative control. In conclusion, RGE and its ginsenosides may enhance hDPC proliferation, activate ERK and AKT signaling pathways in hDPCs, upregulate hair matrix keratinocyte proliferation, and inhibit the DHT-induced androgen receptor transcription. These results suggest that red ginseng may promote hair growth in humans. PMID:25396716

  6. Red Ginseng Extract Promotes the Hair Growth in Cultured Human Hair Follicles

    PubMed Central

    Park, Gyeong-Hun; Park, Ki-young; Cho, Hong-il; Lee, Sang-Min; Han, Ji Su; Chang, Sung Eun; Lee, Mi Woo; Choi, Jee Ho; Moon, Kee Chan; Shin, Hyoseung; Kang, Yong Jung; Lee, Dong Hun

    2015-01-01

    Abstract Ginseng has been shown to promote hair growth in several recent studies. However, its effects on human hair follicles and its mechanisms of action have not been sufficiently elucidated. This study aimed to investigate the hair growth-promoting effects of red ginseng extract (RGE) and its ginsenosides. The proliferative activities of cultured human hair follicles treated with RGE and ginsenoside-Rb1 were assessed using Ki-67 immunostaining. Their effects on isolated human dermal papilla cells (hDPCs) were evaluated using cytotoxicity assays, immunoblot analysis of signaling proteins, and the determination of associated growth factors. We examined the ability of RGE and ginsenosides to protect hair matrix keratinocyte proliferation against dihydrotestosterone (DHT)-induced suppression and their effects on the expression of androgen receptor. The in vivo hair growth-promoting effect of RGE was also investigated in C57BL/6 mice. Both RGE and ginsenoside-Rb1 enhanced the proliferation of hair matrix keratinocytes. hDPCs treated with RGE or ginsenoside-Rb1 exhibited substantial cell proliferation and the associated phosphorylation of ERK and AKT. Moreover, RGE, ginsenoside-Rb1, and ginsenoside-Rg3 abrogated the DHT-induced suppression of hair matrix keratinocyte proliferation and the DHT-induced upregulation of the mRNA expression of androgen receptor in hDPCs. Murine experiments revealed that the subcutaneous injection of 3% RGE resulted in more rapid hair growth than the negative control. In conclusion, RGE and its ginsenosides may enhance hDPC proliferation, activate ERK and AKT signaling pathways in hDPCs, upregulate hair matrix keratinocyte proliferation, and inhibit the DHT-induced androgen receptor transcription. These results suggest that red ginseng may promote hair growth in humans. PMID:25396716

  7. LGR4 and LGR5 Regulate Hair Cell Differentiation in the Sensory Epithelium of the Developing Mouse Cochlea.

    PubMed

    Żak, Magdalena; van Oort, Thijs; Hendriksen, Ferry G; Garcia, Marie-Isabelle; Vassart, Gilbert; Grolman, Wilko

    2016-01-01

    In the developing cochlea, Wnt/β-catenin signaling positively regulates the proliferation of precursors and promotes the formation of hair cells by up-regulating Atoh1 expression. Not much, however, is known about the regulation of Wnt/β-catenin activity in the cochlea. In multiple tissues, the activity of Wnt/β-catenin signaling is modulated by an interaction between LGR receptors and their ligands from the R-spondin family. The deficiency in Lgr4 and Lgr5 genes leads to developmental malformations and lethality. Using the Lgr5 knock-in mouse line we show that loss of LGR5 function increases Wnt/β-catenin activity in the embryonic cochlea, resulting in a mild overproduction of inner and outer hair cells (OHC). Supernumerary hair cells are likely formed due to an up-regulation of the "pro-hair cell" transcription factors Atoh1, Nhlh1, and Pou4f3. Using a hypomorphic Lgr4 mouse model we showed a mild overproduction of OHCs in the heterozygous and homozygous Lgr4 mice. The loss of LGR4 function prolonged the proliferation in the mid-basal turn of E13 cochleae, causing an increase in the number of SOX2-positive precursor cells within the pro-sensory domain. The premature differentiation of hair cells progressed in a medial to lateral gradient in Lgr4 deficient embryos. No significant up-regulation of Atoh1 was observed following Lgr4 deletion. Altogether, our findings suggest that LGR4 and LGR5 play an important role in the regulation of hair cell differentiation in the embryonic cochlea. PMID:27559308

  8. LGR4 and LGR5 Regulate Hair Cell Differentiation in the Sensory Epithelium of the Developing Mouse Cochlea

    PubMed Central

    Żak, Magdalena; van Oort, Thijs; Hendriksen, Ferry G.; Garcia, Marie-Isabelle; Vassart, Gilbert; Grolman, Wilko

    2016-01-01

    In the developing cochlea, Wnt/β-catenin signaling positively regulates the proliferation of precursors and promotes the formation of hair cells by up-regulating Atoh1 expression. Not much, however, is known about the regulation of Wnt/β-catenin activity in the cochlea. In multiple tissues, the activity of Wnt/β-catenin signaling is modulated by an interaction between LGR receptors and their ligands from the R-spondin family. The deficiency in Lgr4 and Lgr5 genes leads to developmental malformations and lethality. Using the Lgr5 knock-in mouse line we show that loss of LGR5 function increases Wnt/β-catenin activity in the embryonic cochlea, resulting in a mild overproduction of inner and outer hair cells (OHC). Supernumerary hair cells are likely formed due to an up-regulation of the “pro-hair cell” transcription factors Atoh1, Nhlh1, and Pou4f3. Using a hypomorphic Lgr4 mouse model we showed a mild overproduction of OHCs in the heterozygous and homozygous Lgr4 mice. The loss of LGR4 function prolonged the proliferation in the mid-basal turn of E13 cochleae, causing an increase in the number of SOX2-positive precursor cells within the pro-sensory domain. The premature differentiation of hair cells progressed in a medial to lateral gradient in Lgr4 deficient embryos. No significant up-regulation of Atoh1 was observed following Lgr4 deletion. Altogether, our findings suggest that LGR4 and LGR5 play an important role in the regulation of hair cell differentiation in the embryonic cochlea. PMID:27559308

  9. Drugs and hair loss.

    PubMed

    Patel, Mansi; Harrison, Shannon; Sinclair, Rodney

    2013-01-01

    Hair loss is a common complaint, both in men and women, and use of prescription medications is widespread. When there is a temporal association between the onset of hair loss and commencement of a medication, the medication is commonly thought to have caused the hair loss. However, hair loss and in particular telogen effluvium may occur in response to a number of triggers including fever, hemorrhage, severe illness, stress, and childbirth, and a thorough exclusion of these potential confounders is necessary before the hair loss can be blamed on the medication. Certain medications are known to cause hair loss by a variety of mechanisms including anagen arrest, telogen effluvium, or accentuation of androgenetic alopecia by androgens. PMID:23159177

  10. Ethnic hair disorders.

    PubMed

    Lindsey, Scott F; Tosti, Antonella

    2015-01-01

    The management of hair and scalp conditions is difficult in any patient, especially given the emotional and psychological implications of hair loss. This undertaking becomes even more challenging in the ethnic patient. Differences in hair care practices, hair shaft morphology, and follicular architecture add complexity to the task. It is imperative that the physician be knowledgeable about these practices and the phenotypic differences seen in ethnic hair in order to appropriately diagnose and treat these patients. In this chapter, we will discuss cultural practices and morphologic differences and explain how these relate to the specific disorders seen in ethnic populations. We will also review the most prominent of the ethnic hair conditions including acquired trichorrhexis nodosa, traction alopecia, central centrifugal cicatricial alopecia, pseudofolliculitis barbae, dissecting cellulitis, and acne keloidalis nuchae. PMID:26370652

  11. Female pattern hair loss.

    PubMed

    Ioannides, Dimitrios; Lazaridou, Elizabeth

    2015-01-01

    Female pattern hair loss, or female pattern androgenetic alopecia, is a nonscarring alopecia with a multi-factorial etiology that mostly affects postmenopausal women and is characterized by a reduction in hair density over the crown and frontal scalp. The clinical picture is characterized by a diffuse rarefaction of scalp hair over the mid-frontal scalp and a more-or-less intact frontal hairline without any signs of inflammation or scarring. Although the disease poses only a cosmetic concern, it is chronic and may have a significant negative psychological impact on the affected person. The aim of treating female pattern hair loss is to reduce hair loss and, to a certain extent, succeed in promoting hair regrowth. Various treatment methods are available, but it remains unclear which are the most effective. Early initiation of treatment and the combination of various modalities seem to be more efficacious than monotherapy. PMID:26370643

  12. Advances and challenges in hair restoration of curly Afrocentric hair.

    PubMed

    Rogers, Nicole E; Callender, Valerie D

    2014-04-01

    Although the biochemical composition of hair is similar among racial and ethnic groups, the hair structure between them varies, and individuals with curly hair pose specific challenges and special considerations when a surgical option for alopecia is considered. Hair restoration in this population should therefore be approached with knowledge on the clinical characteristics of curly hair, hair grooming techniques that may influence the management, unique indications for the procedure, surgical instrumentation used, and the complications that may arise. PMID:24680003

  13. Hair implant complications.

    PubMed

    Hanke, C W; Norins, A L; Pantzer, J G; Bennett, J E

    1981-04-01

    Four men who underwent hair implantation for pattern baldness were treated for complications such as infection, foreign-body reaction, pruritus, and scarring. The complications were similar to those reported with synthetic modacrylic fiber implants that have been used for the same purpose. Although we believe this is the first article to report complications from hair implants, the illogical basis of the procedure suggests that complications will occur in many unsuspecting patients who undergo hair implantation. PMID:7009899

  14. The diaphanous Gene of Drosophila Interacts Antagonistically with multiple wing hairs and Plays a Key Role in Wing Hair Morphogenesis

    PubMed Central

    Lu, Qiuheng; Adler, Paul N.

    2015-01-01

    The Drosophila wing is covered by an array of distally pointing hairs that has served as a key model system for studying planar cell polarity (PCP). The adult cuticular hairs are formed in the pupae from cell extensions that contain extensive actin filaments and microtubules. The importance of the actin cytoskeleton for hair growth and morphogenesis is clear from the wide range of phenotypes seen in mutations in well-known actin regulators. Formin proteins promote the formation of long actin filaments of the sort thought to be important for hair growth. We report here that the formin encoding diaphanous (dia) gene plays a key role in hair morphogenesis. Both loss of function mutations and the expression of a constitutively active Dia led to cells forming both morphologically abnormal hairs and multiple hairs. The conserved frizzled (fz)/starry night (stan) PCP pathway functions to restrict hair initiation and activation of the cytoskeleton to the distal most part of wing cells. It also ensures the formation of a single hair per cell. Our data suggest that the localized inhibition of Dia activity may be part of this mechanism. We found the expression of constitutively active Dia greatly expands the region for activation of the cytoskeleton and that dia functions antagonistically with multiple wing hairs (mwh), the most downstream member of the fz/stan pathway. Further we established that purified fragments of Dia and Mwh could be co-immunoprecipitated suggesting the genetic interaction could reflect a direct physical interaction. PMID:25730111

  15. Recombinant Treponema pallidum rare outer membrane protein 1 (Tromp1) expressed in Escherichia coli has porin activity and surface antigenic exposure.

    PubMed Central

    Blanco, D R; Champion, C I; Exner, M M; Shang, E S; Skare, J T; Hancock, R E; Miller, J N; Lovett, M A

    1996-01-01

    We recently reported the cloning and sequencing of the gene encoding a 31-kDa Treponema pallidum subsp. pallidum rare outer membrane porin protein, designated Tromp1 (D. R. Blanco, C. I. Champion, M. M. Exner, H. Erdjument-Bromage, R. E. W. Hancock, P. Tempst, J. N. Miller, and M. A. Lovett, J. Bacteriol. 177:3556-3562, 1995). Here, we report the stable expression of recombinant Tromp1 (rTromp1) in Escherichia coli. rTromp1 expressed without its signal peptide and containing a 22-residue N-terminal fusion resulted in high-level accumulation of a nonexported soluble protein that was purified to homogeneity by fast protein liquid chromatography (FPLC). Specific antiserum generated to the FPLC-purified rTromp1 fusion identified on immunoblots of T. pallidum the native 31-kDa Tromp1 protein and two higher-molecular-mass oligomeric forms of Tromp1 at 55 and 80 kDa. rTromp1 was also expressed with its native signal peptide by using an inducible T7 promoter. Under these conditions, rTromp1 fractionated predominantly with the E. coli soluble and outer membrane fractions, but not with the inner membrane fraction. rTromp1 isolated from the E. coli outer membrane and reconstituted into planar lipid bilayers showed porin activity based on average single-channel conductances of 0.4 and 0.8 nS in 1 M KCl. Whole-mount immunoelectron microscopy using infection-derived immune serum against T. pallidum indicated that rTromp1 was surface exposed when expressed in E. coli. These findings demonstrate that rTromp1 can be targeted to the E. coli outer membrane, where it has both porin activity and surface antigenic exposure. PMID:8955283

  16. Tarantula hair keratitis.

    PubMed

    Mangat, Simran Singh; Newman, Bill

    2012-10-26

    We describe a 12-year-old boy in England with keratitis secondary to tarantula hairs embedded within the stroma of his cornea. Every attempt must be made to isolate these hairs at the first visit as they have a barbed nature and have a propensity to propagate through ocular tissues. A chronic keratitis requiring long-term steroid use may result if hairs persist in the cornea. Children who keep tarantulas as pets should be instructed on safe handling to prevent the tarantula from adopting defence mechanisms and shedding their hairs. PMID:23242405

  17. Female hair restoration.

    PubMed

    Unger, Robin H

    2013-08-01

    Female hair loss is a devastating issue for women that has only relatively recently been publicly acknowledged as a significant problem. Hair transplant surgery is extremely successful in correcting the most cosmetically problematic areas of alopecia. This article discusses the surgical technique of hair transplantation in women in detail, including pearls to reduce postoperative sequelae and planning strategies to ensure a high degree of patient satisfaction. A brief overview of some of the medical treatments found to be helpful in slowing or reversing female pattern hair loss is included, addressing the available hormonal and topical treatments. PMID:24017982

  18. Laser hair removal pearls.

    PubMed

    Tierney, Emily P; Goldberg, David J

    2008-03-01

    A number of lasers and light devices are now available for the treatment of unwanted hair. The goal of laser hair removal is to damage stem cells in the bulge of the follicle through the targeting of melanin, the endogenous chromophore for laser and light devices utilized to remove hair. The competing chromophores in the skin and hair, oxyhemoglobin and water, have a decreased absorption between 690 nm and 1000 nm, thus making this an ideal range for laser and light sources. Pearls of laser hair removal are presented in this review, focusing on four areas of recent development: 1 treatment of blond, white and gray hair; 2 paradoxical hypertrichosis; 3 laser hair removal in children; and 4 comparison of lasers and IPL. Laser and light-based technologies to remove hair represents one of the most exciting areas where discoveries by dermatologists have led to novel treatment approaches. It is likely that in the next decade, continued advancements in this field will bring us closer to the development of a more permanent and painless form of hair removal. PMID:18330794

  19. Hair tourniquet syndrome: revisited

    PubMed Central

    HUSSIN, P.; MAWARDI, M.; MASRAN, M.S.; GANAISAN, P.

    2015-01-01

    Hair tourniquet syndrome is a rare condition. It is an important emergency condition where urgent attention is needed. In this condition, body appendages are strangulated by hair that acts like a tourniquet. A strand or strands of hair act like a circumferential constriction band and subsequently strangulate the body appendages. Commonly affected sites include fingers, toes or even genitals. Failure to identify and release the acute constriction may result in amputation of affected body part. We report two cases of hair tourniquet syndrome of the thumb and toe that were successfully released without complications. PMID:26712259

  20. Hair Loss in New Moms

    MedlinePlus

    ... Video library Find a dermatologist Hair loss in new moms Many new moms see noticeable hair loss ... regain normal fullness even earlier. Dermatologists’ tips for new mothers If the excessive hair shedding bothers you, ...

  1. Coping with cancer - hair loss

    MedlinePlus

    Alopecia ... after fast-growing cells. While chemo can cause hair loss all over your body, radiation only affects the ... Hair loss usually happens 1 to 3 weeks after the first chemo or radiation treatment. The hair on ...

  2. Coping with cancer -- hair loss

    MedlinePlus

    ... gov/ency/patientinstructions/000914.htm Coping with cancer - hair loss To use the sharing features on this ... lose your hair. Why Cancer Treatments can Cause Hair Loss Many chemotherapy drugs attack fast-growing cells. ...

  3. Why Does Hair Turn Gray?

    MedlinePlus

    ... Each hair follicle contains a certain number of pigment cells. These pigment cells continuously produce a chemical called melanin (say: ... each hair contains. As we get older, the pigment cells in our hair follicles gradually die. When ...

  4. Expression and location of phospho-Artemis (Serine516) in hair follicles during induced growth of mouse hair.

    PubMed

    Wu, Xian-Jie; Zhu, Jian-Wei; Liu, Hai; Lu, Zhong-Fa; Zheng, Min

    2012-05-01

    Artemis has been implicated in having a role in NHEJ, and it is also a multifunctional protein. Previous studies have found Omenn syndrome-like phenotype due to Artemis mutations and associated with alopecia. As Artemis phosphorylation in its c-terminus including Serine516 is prerequisite for the Artemis endonuclease reaction, we postulate that Artemis (Serine516) may be expressed in hair follicle and relate to hair cycling. In this study, hair growth in C57BL/6 mice was induced by plucking the telogen hair on the back. Expression of Artemis (Serine516) in hair follicles during the hair growth cycle was evaluated by immunofluorescence using cryosections and a specific polyclonal anti-Artemis (Serine516) immunoglobulin G (IgG) antibody. It was detected in germ cells, cap, and club hair adjoining the epidermis in telogen. In anagen II, intense staining for Artemis (Serine516) was found in the whole interfollicular epidermis, and in strand keratinocytes. In anagen IV, intense staining for Artemis (Serine516) was detected in basal cells and upper of outer root sheath (ORS) and inner root sheath (IRS). But only upper ORS and lower medulla were stained positive in anagen VI. Upper ORS and lower cortex were positively stained with Artemis (Serine516) in catagen. Based on the phenomenon that the expression of Artemis (Serine516) in mid-anagen and mature anagen was stronger than that in telogen and catagen, we suggest it may take roles in induced growth of mouse hair. PMID:22476261

  5. Stimulatory effect of Brazilian propolis on hair growth through proliferation of keratinocytes in mice.

    PubMed

    Miyata, Shota; Oda, Yozo; Matsuo, Chika; Kumura, Haruto; Kobayashi, Ken

    2014-12-10

    Propolis is a natural honeybee hive product with the potential for use in the treatment of dermatological conditions, such as cutaneous abrasions, burns, and acne. In this study, we investigated whether propolis stimulates hair growth in mice. Ethanol-extracted propolis, which contains various physiologically active substances such as caffeic acid and kaempferol, stimulated anagen induction in shaved back skin. Anagen induction occurred without any detectable abnormalities in the shape of the hair follicles (HFs), hair stem cells in the bulge, proliferating hair matrix keratinocytes in the hair bulb, or localization of versican in the dermal papilla. Propolis treatment also stimulated migration of hair matrix keratinocytes into the hair shaft in HFs during late anagen in the depilated back skin. Organotypic culture of skin containing anagen stage HFs revealed significant stimulation of hair matrix keratinocyte proliferation by propolis. Furthermore, propolis facilitated the proliferation of epidermal keratinocytes. These results indicate that propolis stimulates hair growth by inducing hair keratinocyte proliferation. PMID:25418897

  6. Two proline residues are essential in the calcium-binding activity of rotavirus VP7 outer capsid protein.

    PubMed Central

    Gajardo, R; Vende, P; Poncet, D; Cohen, J

    1997-01-01

    Rotavirus maturation and stability of the outer capsid are calcium-dependent processes. It has been shown previously that the concentration of Ca2+-solubilizing outer capsid proteins from rotavirus particles is dependent on the virus strain. This property of viral particles has been associated with the gene coding for VP7 (gene 9). In this study the correlation between VP7 and resistance to low [Ca2+] was confirmed by analyzing the origin of gene 9 from reassortant viruses prepared under the selective pressure of low [Ca2+]. After chemical mutagenesis, we selected mutant viruses of the bovine strain RF that are more resistant to low [Ca2+]. The genes coding for the VP7 proteins of these independent mutants have been sequenced. Sequence analysis confirmed that these mutants are independent and revealed that all mutant VP7 proteins have proline 75 changed to leucine and have an outer capsid that solubilized at low [Ca2+]. The mutation of proline 279 to serine is found in all but two mutants. The phenotype of mutants having a single proline change can be distinguished from the phenotype of mutants having two proline changes. Sequence analysis showed that position 75 is in a region (amino acids 65 to 78) of great variability and that proline 75 is present in most of the bovine strains. In contrast, proline 279 is in a conserved region and is conserved in all the VP7 sequences in data banks. This region is rich in oxygenated residues that are correctly allocated in the metal-coordinating positions of the Ca2+-binding EF-hand structure pattern, suggesting that this region is important in the Ca2+ binding of VP7. PMID:9032355

  7. Functional Activities and Epitope Specificity of Human and Murine Antibodies against the Class 4 Outer Membrane Protein (Rmp) of Neisseria meningitidis

    PubMed Central

    Rosenqvist, Einar; Musacchio, Alexis; Aase, Audun; Høiby, E. Arne; Namork, Ellen; Kolberg, Jan; Wedege, Elisabeth; Delvig, Alexei; Dalseg, Rolf; Michaelsen, Terje E.; Tommassen, Jan

    1999-01-01

    Antibodies against the class 4 outer membrane protein (OMP) from Neisseria meningitidis have been purified from sera from vaccinees immunized with the Norwegian meningococcal group B outer membrane vesicle vaccine. The human sera and purified antibodies reacted strongly with the class 4 OMP in immunoblots, whereas experiments with whole bacteria showed only weak reactions, indicating that the antibodies mainly reacted with parts of the class 4 molecule that were not exposed. The purified human anti-class 4 OMP antibodies and the monoclonal antibodies (MAbs) were neither bactericidal nor opsonic against live meningococci. Three new MAbs against the class 4 OMP were generated and compared with other, previously described MAbs. Three linear epitopes in different regions of the class 4 OMP were identified by the reaction of MAbs with synthetic peptides. The MAbs showed no blocking effect on bactericidal activity of MAbs against other OMPs. However, one of the eight purified human anti-class 4 OMP antibody preparations, selected from immunoblot reactions among sera from 27 vaccinees, inhibited at high concentrations the bactericidal effect of a MAb against the class 1 OMP. However, these antibodies were not vaccine induced, as they were present also before vaccination. Therefore, this study gave no evidence that vaccination with a meningococcal outer membrane vesicle vaccine containing the class 4 OMP induces blocking antibodies. Our data indicated that the structure of class 4 OMP does not correspond to standard β-barrel structures of integral OMPs and that no substantial portion of the OmpA-like C-terminal region of this protein is located at the surface of the outer membrane. PMID:10024570

  8. Thermoelectric Outer Planets Spacecraft (TOPS)

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The research and advanced development work is reported on a ballistic-mode, outer planet spacecraft using radioisotope thermoelectric generator (RTG) power. The Thermoelectric Outer Planet Spacecraft (TOPS) project was established to provide the advanced systems technology that would allow the realistic estimates of performance, cost, reliability, and scheduling that are required for an actual flight mission. A system design of the complete RTG-powered outer planet spacecraft was made; major technical innovations of certain hardware elements were designed, developed, and tested; and reliability and quality assurance concepts were developed for long-life requirements. At the conclusion of its active phase, the TOPS Project reached its principal objectives: a development and experience base was established for project definition, and for estimating cost, performance, and reliability; an understanding of system and subsystem capabilities for successful outer planets missions was achieved. The system design answered long-life requirements with massive redundancy, controlled by on-board analysis of spacecraft performance data.

  9. Help! It's Hair Loss!

    MedlinePlus

    ... Homework? Here's Help White House Lunch Recipes Help! It's Hair Loss! KidsHealth > For Kids > Help! It's Hair Loss! Print A A A Text Size ... part above the skin, is dead. (That's why it doesn't hurt to get a haircut!) This ...

  10. Hair Casts or Pseudonits

    PubMed Central

    França, Katlein; Villa, Ricardo Tadeu; Silva, Isabella Rezende; de Carvalho, Cristine Almeida; Bedin, Valcinir

    2011-01-01

    Hair casts or pseudonits are thin, elongated, cylindrical concretions that encircle the hair shaft and can be easily dislodged. A case of pseudonits in a 9-year-old girl is reported. Though not unusual, false diagnoses are common. PMID:22223977

  11. Deletion of Brg1 causes abnormal hair cell planer polarity, hair cell anchorage, and scar formation in mouse cochlea.

    PubMed

    Jin, Yecheng; Ren, Naixia; Li, Shiwei; Fu, Xiaolong; Sun, Xiaoyang; Men, Yuqin; Xu, Zhigang; Zhang, Jian; Xie, Yue; Xia, Ming; Gao, Jiangang

    2016-01-01

    Hair cells (HCs) are mechanosensors that play crucial roles in perceiving sound, acceleration, and fluid motion. The precise architecture of the auditory epithelium and its repair after HC loss is indispensable to the function of organ of Corti (OC). In this study, we showed that Brg1 was highly expressed in auditory HCs. Specific deletion of Brg1 in postnatal HCs resulted in rapid HC degeneration and profound deafness in mice. Further experiments showed that cell-intrinsic polarity of HCs was abolished, docking of outer hair cells (OHCs) by Deiter's cells (DCs) failed, and scar formation in the reticular lamina was deficient. We demonstrated that Brg1 ablation disrupted the Gαi/Insc/LGN and aPKC asymmetric distributions, without overt effects on the core planer cell polarity (PCP) pathway. We also demonstrated that Brg1-deficient HCs underwent apoptosis, and that leakage in the reticular lamina caused by deficient scar formation shifted the mode of OHC death from apoptosis to necrosis. Together, these data demonstrated a requirement for Brg1 activity in HC development and suggested a role for Brg1 in the proper cellular structure formation of HCs. PMID:27255603

  12. Deletion of Brg1 causes abnormal hair cell planer polarity, hair cell anchorage, and scar formation in mouse cochlea

    PubMed Central

    Jin, Yecheng; Ren, Naixia; Li, Shiwei; Fu, Xiaolong; Sun, Xiaoyang; Men, Yuqin; Xu, Zhigang; Zhang, Jian; Xie, Yue; Xia, Ming; Gao, Jiangang

    2016-01-01

    Hair cells (HCs) are mechanosensors that play crucial roles in perceiving sound, acceleration, and fluid motion. The precise architecture of the auditory epithelium and its repair after HC loss is indispensable to the function of organ of Corti (OC). In this study, we showed that Brg1 was highly expressed in auditory HCs. Specific deletion of Brg1 in postnatal HCs resulted in rapid HC degeneration and profound deafness in mice. Further experiments showed that cell-intrinsic polarity of HCs was abolished, docking of outer hair cells (OHCs) by Deiter’s cells (DCs) failed, and scar formation in the reticular lamina was deficient. We demonstrated that Brg1 ablation disrupted the Gαi/Insc/LGN and aPKC asymmetric distributions, without overt effects on the core planer cell polarity (PCP) pathway. We also demonstrated that Brg1-deficient HCs underwent apoptosis, and that leakage in the reticular lamina caused by deficient scar formation shifted the mode of OHC death from apoptosis to necrosis. Together, these data demonstrated a requirement for Brg1 activity in HC development and suggested a role for Brg1 in the proper cellular structure formation of HCs. PMID:27255603

  13. Laser hair removal.

    PubMed

    Wanner, Molly

    2005-01-01

    Since 1996, there have been numerous advances in hair laser removal that utilize melanin as a chromophore. All of the devices on the market may be used in patients with light skin (phototypes I-III) and yield hair reduction near 75%. The ruby (694 nm) laser, alexandrite (755 nm) laser, and diode (810 nm) laser, as well as intense pulsed light are commonly used devices for hair laser removal. The long-pulsed Nd:YAG (1064 nm) laser represents the safest device for hair removal in dark-skinned patients because of its long wavelength, although the diode laser, alexandrite laser, and intense pulse light may be used. For treatment of light hair, combination radiofrequency and optical devices as well as photodynamic therapy are under investigation. PMID:16229722

  14. Structure, activity and interactions of the cysteine deleted analog of tachyplesin-1 with lipopolysaccharide micelle: Mechanistic insights into outer-membrane permeabilization and endotoxin neutralization.

    PubMed

    Saravanan, Rathi; Mohanram, Harini; Joshi, Mangesh; Domadia, Prerna N; Torres, Jaume; Ruedl, Christiane; Bhattacharjya, Surajit

    2012-07-01

    Tachyplesin-1, a disulfide stabilized beta-hairpin antimicrobial peptide, can be found at the hemocytes of horse shoe crab Tachypleus tridentatus. A cysteine deleted linear analog of tachyplesin-1 or CDT (KWFRVYRGIYRRR-NH2) contains a broad spectrum of bactericidal activity with a reduced hemolytic property. The bactericidal activity of CDT stems from selective interactions with the negatively charged lipids including LPS. In this work, CDT-LPS interactions were investigated using NMR spectroscopy, optical spectroscopy and functional assays. We found that CDT neutralized LPS and disrupted permeability barrier of the outer membrane. Zeta potential and ITC studies demonstrated charge compensation and hydrophobic interactions of CDT with the LPS-outer membrane, respectively. Secondary structure of the peptide was probed by CD and FT-IR experiments indicating beta-strands and/or beta-turn conformations in the LPS micelle. An ensemble of structures, determined in LPS micelle by NMR, revealed a beta-hairpin like topology of the CDT peptide that was typified by an extended cationic surface and a relatively shorter segment of hydrophobic region. Interestingly, at the non-polar face, residue R11 was found to be in a close proximity to the indole ring of W2, suggesting a cation-n type interactions. Further, saturation transfer difference (STD) NMR studies established intimate contacts among the aromatic and cationic residues of CDT with the LPS micelle. Fluorescence and dynamic light scattering experiments demonstrated that CDT imparted structural destabilization to the aggregated states of LPS. Collectively, atomic resolution structure and interactions of CDT with the outer membrane-LPS could be exploited for developing potent broad spectrum antimicrobial and anti-sepsis agents. PMID:22464970

  15. The mechanisms of complement activation in normal bovine serum and normal horse serum against Yersinia enterocolitica O:9 strains with different outer membrane proteins content.

    PubMed

    Miętka, K; Brzostek, K; Guz-Regner, K; Bugla-Płoskońska, G

    2016-01-01

    Yersinia enterocolitica is a common zoonotic pathogen and facultative intracellular bacterium which can survive within blood cells. Cattle and horses are considered a reservoir of Y. enterocolitica which often causes several serious syndromes associated with yersiniosis such as abortions, premature births or infertility. The aim of our investigation was to determine the vitality of Y. enterocolitica O:9 strains (Ye9) in bovine and horse sera (NBS and NHrS) and explain the role of outer membrane proteins (OMPs) in serum resistance of these bacteria. Our previous studies demonstrated moderate human serum (NHS) resistance of the wild type Ye9 strain, whereas mutants lacking YadA, Ail or OmpC remained sensitive to the bactericidal activity of NHS. The present study showed that the wild type of Ye9 strain was resistant to the bactericidal activity of both NHrS and NBS, while Ye9 mutants lacking the YadA, Ail and OmpC proteins were sensitive to NHrS and NBS as well as to NHS. The mechanisms of complement activation against Ye9 strains lacking Ail and YadA were distinguished, i.e. activation of the classical/lectin pathways decisive in the bactericidal mechanism of complement activation of NBS, parallel activation of the classical/lectin and alternative pathways of NHrS. In this research the mechanism of independent activation of the classical/lectin or the alternative pathway of NBS and NHrS against Ye9 lacking OmpC porin was also established. The results indicate that serum resistance of Ye9 is multifactorial, in which extracellular structures, i.e. outer membrane proteins (OMPs) such as Ail, OmpC or YadA, play the main role. PMID:27096793

  16. Hair Cell Overexpression of Islet1 Reduces Age-Related and Noise-Induced Hearing Loss

    PubMed Central

    Huang, Mingqian; Kantardzhieva, Albena; Scheffer, Deborah; Liberman, M. Charles

    2013-01-01

    Isl1 is a LIM-homeodomain transcription factor that is critical in the development and differentiation of multiple tissues. In the mouse inner ear, Isl1 is expressed in the prosensory region of otocyst, in young hair cells and supporting cells, and is no longer expressed in postnatal auditory hair cells. To evaluate how continuous Isl1 expression in postnatal hair cells affects hair cell development and cochlear function, we created a transgenic mouse model in which the Pou4f3 promoter drives Isl1 overexpression specifically in hair cells. Isl1 overexpressing hair cells develop normally, as seen by morphology and cochlear functions (auditory brainstem response and otoacoustic emissions). As the mice aged to 17 months, wild-type (WT) controls showed the progressive threshold elevation and outer hair cell loss characteristic of the age-related hearing loss (ARHL) in the background strain (C57BL/6J). In contrast, the Isl1 transgenic mice showed significantly less threshold elevation with survival of hair cells. Further, the Isl1 overexpression protected the ear from noise-induced hearing loss (NIHL): both ABR threshold shifts and hair cell death were significantly reduced when compared with WT littermates. Our model suggests a common mechanism underlying ARHL and NIHL, and provides evidence that hair cell-specific Isl1 expression can promote hair cell survival and therefore minimize the hearing impairment that normally occurs with aging and/or acoustic overexposure. PMID:24048839

  17. ROOT HAIR DEFECTIVE SIX-LIKE Class I Genes Promote Root Hair Development in the Grass Brachypodium distachyon.

    PubMed

    Kim, Chul Min; Dolan, Liam

    2016-08-01

    Genes encoding ROOT HAIR DEFECTIVE SIX-LIKE (RSL) class I basic helix loop helix proteins are expressed in future root hair cells of the Arabidopsis thaliana root meristem where they positively regulate root hair cell development. Here we show that there are three RSL class I protein coding genes in the Brachypodium distachyon genome, BdRSL1, BdRSL2 and BdRSL3, and each is expressed in developing root hair cells after the asymmetric cell division that forms root hair cells and hairless epidermal cells. Expression of BdRSL class I genes is sufficient for root hair cell development: ectopic overexpression of any of the three RSL class I genes induces the development of root hairs in every cell of the root epidermis. Expression of BdRSL class I genes in root hairless Arabidopsis thaliana root hair defective 6 (Atrhd6) Atrsl1 double mutants, devoid of RSL class I function, restores root hair development indicating that the function of these proteins has been conserved. However, neither AtRSL nor BdRSL class I genes is sufficient for root hair development in A. thaliana. These data demonstrate that the spatial pattern of class I RSL activity can account for the pattern of root hair cell differentiation in B. distachyon. However, the spatial pattern of class I RSL activity cannot account for the spatial pattern of root hair cells in A. thaliana. Taken together these data indicate that that the functions of RSL class I proteins have been conserved among most angiosperms-monocots and eudicots-despite the dramatically different patterns of root hair cell development. PMID:27494519

  18. ROOT HAIR DEFECTIVE SIX-LIKE Class I Genes Promote Root Hair Development in the Grass Brachypodium distachyon

    PubMed Central

    Kim, Chul Min

    2016-01-01

    Genes encoding ROOT HAIR DEFECTIVE SIX-LIKE (RSL) class I basic helix loop helix proteins are expressed in future root hair cells of the Arabidopsis thaliana root meristem where they positively regulate root hair cell development. Here we show that there are three RSL class I protein coding genes in the Brachypodium distachyon genome, BdRSL1, BdRSL2 and BdRSL3, and each is expressed in developing root hair cells after the asymmetric cell division that forms root hair cells and hairless epidermal cells. Expression of BdRSL class I genes is sufficient for root hair cell development: ectopic overexpression of any of the three RSL class I genes induces the development of root hairs in every cell of the root epidermis. Expression of BdRSL class I genes in root hairless Arabidopsis thaliana root hair defective 6 (Atrhd6) Atrsl1 double mutants, devoid of RSL class I function, restores root hair development indicating that the function of these proteins has been conserved. However, neither AtRSL nor BdRSL class I genes is sufficient for root hair development in A. thaliana. These data demonstrate that the spatial pattern of class I RSL activity can account for the pattern of root hair cell differentiation in B. distachyon. However, the spatial pattern of class I RSL activity cannot account for the spatial pattern of root hair cells in A. thaliana. Taken together these data indicate that that the functions of RSL class I proteins have been conserved among most angiosperms—monocots and eudicots—despite the dramatically different patterns of root hair cell development. PMID:27494519

  19. LSD1 is Required for Hair Cell Regeneration in Zebrafish.

    PubMed

    He, Yingzi; Tang, Dongmei; Cai, Chengfu; Chai, Renjie; Li, Huawei

    2016-05-01

    Lysine-specific demethylase 1 (LSD1/KDM1A) plays an important role in complex cellular processes such as differentiation, proliferation, apoptosis, and cell cycle progression. It has recently been demonstrated that during development, downregulation of LSD1 inhibits cell proliferation, modulates the expression of cell cycle regulators, and reduces hair cell formation in the zebrafish lateral line, which suggests that LSD1-mediated epigenetic regulation plays a key role in the development of hair cells. However, the role of LSD1 in hair cell regeneration after hair cell loss remains poorly understood. Here, we demonstrate the effect of LSD1 on hair cell regeneration following neomycin-induced hair cell loss. We show that the LSD1 inhibitor trans-2-phenylcyclopropylamine (2-PCPA) significantly decreases the regeneration of hair cells in zebrafish after neomycin damage. In addition, immunofluorescent staining demonstrates that 2-PCPA administration suppresses supporting cell proliferation and alters cell cycle progression. Finally, in situ hybridization shows that 2-PCPA significantly downregulates the expression of genes related to Wnt/β-catenin and Fgf activation. Altogether, our data suggest that downregulation of LSD1 significantly decreases hair cell regeneration after neomycin-induced hair cell loss through inactivation of the Wnt/β-catenin and Fgf signaling pathways. Thus, LSD1 plays a critical role in hair cell regeneration and might represent a novel biomarker and potential therapeutic approach for the treatment of hearing loss. PMID:26008620

  20. Amplitude death of coupled hair bundles with stochastic channel noise

    NASA Astrophysics Data System (ADS)

    Kim, Kyung-Joong; Ahn, Kang-Hun

    2014-04-01

    Hair cells conduct auditory transduction in vertebrates. In lower vertebrates such as frogs and turtles, due to the active mechanism in hair cells, hair bundles (stereocilia) can be spontaneously oscillating or quiescent. Recently an amplitude death phenomenon has been proposed [K.-H. Ahn, J. R. Soc. Interface, 10, 20130525 (2013)] as a mechanism for auditory transduction in frog hair-cell bundles, where sudden cessation of the oscillations arises due to the coupling between nonidentical hair bundles. The gating of the ion channel is intrinsically stochastic due to the stochastic nature of the configuration change of the channel. The strength of the noise due to the channel gating can be comparable to the thermal Brownian noise of hair bundles. Thus, we perform stochastic simulations of the elastically coupled hair bundles. In spite of stray noisy fluctuations due to its stochastic dynamics, our simulation shows the transition from collective oscillation to amplitude death as interbundle coupling strength increases. In its stochastic dynamics, the formation of the amplitude death state of coupled hair bundles can be seen as a sudden suppression of the displacement fluctuation of the hair bundles as the coupling strength increases. The enhancement of the signal-to-noise ratio through the amplitude death phenomenon is clearly seen in the stochastic dynamics. Our numerical results demonstrate that the multiple number of transduction channels per hair bundle is an important factor to the amplitude death phenomenon, because the phenomenon may disappear for a small number of transduction channels due to strong gating noise.

  1. A central to peripheral progression of cell cycle exit and hair cell differentiation in the developing mouse cristae.

    PubMed

    Slowik, Amber D; Bermingham-McDonogh, Olivia

    2016-03-01

    The inner ear contains six distinct sensory organs that each maintains some ability to regenerate hair cells into adulthood. In the postnatal cochlea, there appears to be a relationship between the developmental maturity of a region and its ability to regenerate as postnatal regeneration largely occurs in the apical turn, which is the last region to differentiate and mature during development. In the mature cristae there are also regional differences in regenerative ability, which led us to hypothesize that there may be a general relationship between the relative maturity of a region and the regenerative competence of that region in all of the inner ear sensory organs. By analyzing adult mouse cristae labeled embryonically with BrdU, we found that hair cell birth starts in the central region and progresses to the periphery with age. Since the peripheral region of the adult cristae also maintains active Notch signaling and some regenerative competence, these results are consistent with the hypothesis that the last regions to develop retain some of their regenerative ability into adulthood. Further, by analyzing embryonic day 14.5 inner ears we provide evidence for a wave of hair cell birth along the longitudinal axis of the cristae from the central regions to the outer edges. Together with the data from the adult inner ears labeled with BrdU as embryos, these results suggest that hair cell differentiation closely follows cell cycle exit in the cristae, unlike in the cochlea where they are uncoupled. PMID:26826497

  2. Preoperative hair removal.

    PubMed

    Hamilton, H W; Hamilton, K R; Lone, F J

    1977-05-01

    This study compares the efficiency, safety and cost of hair removal before surgery, with a safety razor, an electric clipper and a depilatory. It was found that both the razor and the clipper damaged the surface of the skin, while the depilatory caused a mild lymphocytic reaction in the upper dermis. The depilatory was expensive and may cause sensitivity reactions in a few individuals, but was found to be the easiest and most efficient method of removing hair. It was concluded that if hair has to be removed a depilatory is the agent of choice. PMID:870157

  3. Complications in hair restoration.

    PubMed

    Lam, Samuel M

    2013-11-01

    Hair restoration requires a high level of specialized skill on the part of both the surgeon and the assistant team. Recipient-site problems can manifest from either surgeon or assistant error. The surgeon can create an unnatural hairline due to lack of knowledge of natural hair-loss patterns or badly executed recipient sites. He must also be cognizant of how hairs naturally are angled on the scalp to re-create a pattern that appears natural when making recipient sites. Assistants can also greatly contribute to the success or failure of surgery in their task of graft dissection and graft placement. PMID:24200385

  4. Hair and scalp dermatoscopy.

    PubMed

    Miteva, Mariya; Tosti, Antonella

    2012-11-01

    Dermatoscopy is a noninvasive diagnostic tool that allows the recognition of morphologic structures not visible by the naked eye. Trichoscopy (scalp dermatoscopy and videodermatoscopy) is useful for the diagnosis and follow-up of hair and scalp disorders. However, it is not widely used in the management of hair disorders. This review provides updated information from the literature and our experience on the dermoscopic features of the most common hair and scalp disorders. This will enable dermatologists to make fast diagnoses of tinea capitis and alopecia areata, distinguish early androgenetic alopecia from telogen effluvium, and differentiate scarring from nonscarring alopecia. PMID:22405573

  5. Topical Treatment of Hair Loss with Formononetin by Modulating Apoptosis.

    PubMed

    Kim, Mi Hye; Choi, You Yeon; Lee, Ji Eun; Kim, Kyuseok; Yang, Woong Mo

    2016-01-01

    Formononetin is one of the main components of red clover plants and its role on hair regrowth against hair loss has not been established yet. In the present study, we assessed the potential effects of formononetin on alopecia, along with impaired hair cycles by induction of apoptosis-regression.Depilated C57BL/6 mice were used for monitoring the hair cycles. Formononetin (1 and 100 µM) was topically treated to the dorsal skin for 14 days. Topical formononetin treatment induced miniaturized hair follicles to recover to normal sizes. Tapering hair shaft began to grow newly, emerging from the hair follicles by formononetin. In addition, formononetin inhibited the activation of caspase-8 and decreased the procaspase-9 expression. As a result of formononetin treatment, anti-apoptotic Bcl-2 was up-regulated, whereas pro-apoptotic Bax and p53 were down-regulated, resulting in a decrease of caspase-3 activation. Formononetin showed the obvious inhibition of apoptosis under terminal deoxynucleotidyl transferase dUTP nick end labeling staining thereafter.Taken together, our findings demonstrate that formononetin exerted the hair regrowth effect on hair loss, in which the underlying mechanisms were associated with Fas/Fas L-induced caspase activation, thus inhibiting apoptosis. PMID:26756818

  6. Extraction and Analysis of Cortisol from Human and Monkey Hair

    PubMed Central

    Meyer, Jerrold; Novak, Melinda; Hamel, Amanda; Rosenberg, Kendra

    2014-01-01

    The stress hormone cortisol (CORT) is slowly incorporated into the growing hair shaft of humans, nonhuman primates, and other mammals. We developed and validated a method for CORT extraction and analysis from rhesus monkey hair and subsequently adapted this method for use with human scalp hair. In contrast to CORT "point samples" obtained from plasma or saliva, hair CORT provides an integrated measure of hypothalamic-pituitary-adrenocortical (HPA) system activity, and thus physiological stress, during the period of hormone incorporation. Because human scalp hair grows at an average rate of 1 cm/month, CORT levels obtained from hair segments several cm in length can potentially serve as a biomarker of stress experienced over a number of months. In our method, each hair sample is first washed twice in isopropanol to remove any CORT from the outside of the hair shaft that has been deposited from sweat or sebum. After drying, the sample is ground to a fine powder to break up the hair's protein matrix and increase the surface area for extraction. CORT from the interior of the hair shaft is extracted into methanol, the methanol is evaporated, and the extract is reconstituted in assay buffer. Extracted CORT, along with standards and quality controls, is then analyzed by means of a sensitive and specific commercially available enzyme immunoassay (EIA) kit. Readout from the EIA is converted to pg CORT per mg powdered hair weight. This method has been used in our laboratory to analyze hair CORT in humans, several species of macaque monkeys, marmosets, dogs, and polar bears. Many studies both from our lab and from other research groups have demonstrated the broad applicability of hair CORT for assessing chronic stress exposure in natural as well as laboratory settings. PMID:24513702

  7. Extraction and analysis of cortisol from human and monkey hair.

    PubMed

    Meyer, Jerrold; Novak, Melinda; Hamel, Amanda; Rosenberg, Kendra

    2014-01-01

    The stress hormone cortisol (CORT) is slowly incorporated into the growing hair shaft of humans, nonhuman primates, and other mammals. We developed and validated a method for CORT extraction and analysis from rhesus monkey hair and subsequently adapted this method for use with human scalp hair. In contrast to CORT "point samples" obtained from plasma or saliva, hair CORT provides an integrated measure of hypothalamic-pituitary-adrenocortical (HPA) system activity, and thus physiological stress, during the period of hormone incorporation. Because human scalp hair grows at an average rate of 1 cm/month, CORT levels obtained from hair segments several cm in length can potentially serve as a biomarker of stress experienced over a number of months. In our method, each hair sample is first washed twice in isopropanol to remove any CORT from the outside of the hair shaft that has been deposited from sweat or sebum. After drying, the sample is ground to a fine powder to break up the hair's protein matrix and increase the surface area for extraction. CORT from the interior of the hair shaft is extracted into methanol, the methanol is evaporated, and the extract is reconstituted in assay buffer. Extracted CORT, along with standards and quality controls, is then analyzed by means of a sensitive and specific commercially available enzyme immunoassay (EIA) kit. Readout from the EIA is converted to pg CORT per mg powdered hair weight. This method has been used in our laboratory to analyze hair CORT in humans, several species of macaque monkeys, marmosets, dogs, and polar bears. Many studies both from our lab and from other research groups have demonstrated the broad applicability of hair CORT for assessing chronic stress exposure in natural as well as laboratory settings. PMID:24513702

  8. Elevated hair cortisol concentrations in endurance athletes.

    PubMed

    Skoluda, Nadine; Dettenborn, Lucia; Stalder, Tobias; Kirschbaum, Clemens

    2012-05-01

    Engaging in intensive aerobic exercise, specifically endurance sports, is associated with HPA axis activation indicated by elevated cortisol levels. Whether the repeated short-term elevations in cortisol levels result in higher long-term cortisol exposure of endurance athletes has been difficult to examine since traditional methods of cortisol assessments (saliva, blood, urine) reflect only relatively short time periods. Hair segment analysis provides a new method to assess cumulative cortisol secretion over prolonged time periods in a retrospective fashion. The aim of this study was to investigate cumulative cortisol secretion over several months reflecting intensive training and competitive races by examining hair cortisol levels of endurance athletes. Hair samples were obtained from 304 amateur endurance athletes (long-distance runners, triathletes, cyclists) and 70 controls. Cortisol concentrations were determined in the first to third 3-cm hair segments most proximal to the scalp. In addition, self-report measures of training volume were obtained. Endurance athletes exhibited higher cortisol levels in all three hair segments compared to controls (p<.001). Positive correlations between the cortisol concentration in the first hair segment and each indicator of training volume were found (all p<.01). These data suggest that repeated physical stress of intensive training and competitive races among endurance athletes is associated with elevated cortisol exposure over prolonged periods of time. These findings may have important implications with regard to somatic and mental health of athletes which should be investigated in future research. PMID:21944954

  9. Advances in Understanding Hair Growth.

    PubMed

    Bernard, Bruno A

    2016-01-01

    In this short review, I introduce an integrated vision of human hair follicle behavior and describe opposing influences that control hair follicle homeostasis, from morphogenesis to hair cycling. The interdependence and complementary roles of these influences allow us to propose that the hair follicle is a true paradigm of a "Yin Yang" type, that is a cold/slow-hot/fast duality. Moreover, a new promising field is emerging, suggesting that glycans are key elements of hair follicle growth control. PMID:26918186

  10. Relative importances of outer membrane permeability and group 1 beta-lactamase as determinants of meropenem and imipenem activities against Enterobacter cloacae.

    PubMed Central

    Cornaglia, G; Russell, K; Satta, G; Fontana, R

    1995-01-01

    The roles of outer membrane permeability and Bush group 1 beta-lactamase activity in determining Enterobacter cloacae susceptibility to either meropenem or imipenem were investigated. A beta-lactamase-deficient strain was obtained by mutagenesis from a clinical isolate of E. cloacae, and a porin-deficient strain was selected from this mutant with cefoxitin. Both strains were transformed with the plasmid pAA20R, which contained the gene coding for the carbapenem-hydrolyzing CphA beta-lactamase, and the carbapenem permeability coefficients were measured by the Zimmermann and Rosselet technique (W. Zimmermann and A. Rosselet, Antimicrob. Agents Chemother. 12:368-372, 1977). The permeability coefficient of meropenem was roughly half that of imipenem in the normally permeable strain and almost seven times lower than that of imipenem in the porin-deficient strain. In the porin-deficient strain, the virtual absence of porins caused the MICs of meropenem to increase from 8 to 16 times, while it did not affect the MICs of imipenem. Conversely, the beta-lactamase affected imipenem but not meropenem activity: meropenem showed a similar activity in the parent strain and in the beta-lactamase-deficient mutant with both a low- and high-density inoculum, whereas imipenem was 16 times less active against the parent strain when the high-density inoculum was used. It is concluded that outer membrane permeability and stability to group 1 beta-lactamase have different impacts on the activities of meropenem and imipenem against E. cloacae. PMID:7726496

  11. Laminin-511, inducer of hair growth, is down-regulated and its suppressor in hair growth, laminin-332 up-regulated in chemotherapy-induced alopecia

    PubMed Central

    Imanishi, Hisayoshi; Tsuruta, Daisuke; Tateishi, Chiharu; Sugawara, Koji; Paus, Ralf; Tsuji, Tsutomu; Ishii, Masamitsu; Ikeda, Kazuo; Kunimoto, Hiroyuki; Nakajima, Koichi; Jones, Jonathan C.R.; Kobayashi, Hiromi

    2010-01-01

    Background Chemotherapy-induced alopecia (CIA) has a devastating cosmetic effect, especially in the young. Recent data indicate that two major basement membrane components (laminin-332 and -511) of the skin have opposing effects on hair growth. Objective In this study, we examined the role and localization of laminin-332 and -511 in CIA. Methods We examined the expression of laminin-332 and -511 during the dystrophic catagen form of CIA induced in C57BL/6 mice by cyclophosphamide (CYP) treatment. Results Our data indicate that both laminin-332 and its receptor α6β4 integrin are up-regulated (both quantitatively and spatially) after mid to late dystrophic catagen around the outer root sheath (ORS) in the lower third of hair follicles in CIA. This up-regulation also occurs at the transcriptional level. In contrast, laminin-511 is down-regulated after mid dystrophic catagen at the protein level, with transcriptional inactivation of laminin-511 occurring transiently at the early dystrophic catagen stage in both epidermal and ORS keratinocytes. Laminin-511 expression correlates with expression of α3 integrin in CIA and we also demonstrate that laminin-511 can up-regulate the activity of the α3 integrin promoter in cultured keratinocytes. Injection of a laminin-511 rich protein extract, but not recombinant laminin-332, in the back skin of mice delays hair loss in CYP-induced CIA. Conclusions We propose that abrupt hair loss in CIA is, at least in part, caused by down-regulation of laminin-511 and up-regulation of laminin-332 at the transcriptional and translational levels. PMID:20211547

  12. Mechanosensory hairs in bumblebees (Bombus terrestris) detect weak electric fields

    PubMed Central

    Sutton, Gregory P.; Clarke, Dominic; Morley, Erica L.; Robert, Daniel

    2016-01-01

    Bumblebees (Bombus terrestris) use information from surrounding electric fields to make foraging decisions. Electroreception in air, a nonconductive medium, is a recently discovered sensory capacity of insects, yet the sensory mechanisms remain elusive. Here, we investigate two putative electric field sensors: antennae and mechanosensory hairs. Examining their mechanical and neural response, we show that electric fields cause deflections in both antennae and hairs. Hairs respond with a greater median velocity, displacement, and angular displacement than antennae. Extracellular recordings from the antennae do not show any electrophysiological correlates to these mechanical deflections. In contrast, hair deflections in response to an electric field elicited neural activity. Mechanical deflections of both hairs and antennae increase with the electric charge carried by the bumblebee. From this evidence, we conclude that sensory hairs are a site of electroreception in the bumblebee. PMID:27247399

  13. Mechanosensory hairs in bumblebees (Bombus terrestris) detect weak electric fields.

    PubMed

    Sutton, Gregory P; Clarke, Dominic; Morley, Erica L; Robert, Daniel

    2016-06-28

    Bumblebees (Bombus terrestris) use information from surrounding electric fields to make foraging decisions. Electroreception in air, a nonconductive medium, is a recently discovered sensory capacity of insects, yet the sensory mechanisms remain elusive. Here, we investigate two putative electric field sensors: antennae and mechanosensory hairs. Examining their mechanical and neural response, we show that electric fields cause deflections in both antennae and hairs. Hairs respond with a greater median velocity, displacement, and angular displacement than antennae. Extracellular recordings from the antennae do not show any electrophysiological correlates to these mechanical deflections. In contrast, hair deflections in response to an electric field elicited neural activity. Mechanical deflections of both hairs and antennae increase with the electric charge carried by the bumblebee. From this evidence, we conclude that sensory hairs are a site of electroreception in the bumblebee. PMID:27247399

  14. Scurvy, corkscrew hair (image)

    MedlinePlus

    Scurvy is a nutritional disease caused by deficiency of vitamin C. Pinpoint bleeding around hair follicles, and " ... this picture, can occur as a result of scurvy. Bleeding along the gums is common. This disease ...

  15. Hair Treatments and Pregnancy

    MedlinePlus

    ... is likely that only a small amount of hair straightening products are actually absorbed into your system, so the developing baby would only be exposed to small amounts. I work full time as a cosmetologist and recently became ...

  16. Hair Loss (Alopecia)

    MedlinePlus

    ... for these devices are not known. Prescription medicine Finasteride: The FDA approved this medicine to treat men ... hair re-growth in many (about 66%) men. Finasteride works by stopping the body from making a ...

  17. Eps8 Regulates Hair Bundle Length and Functional Maturation of Mammalian Auditory Hair Cells

    PubMed Central

    Waldhaus, Jörg; Xiong, Hao; Hackney, Carole M.; Holley, Matthew C.; Offenhauser, Nina; Di Fiore, Pier Paolo; Knipper, Marlies; Masetto, Sergio; Marcotti, Walter

    2011-01-01

    Hair cells of the mammalian cochlea are specialized for the dynamic coding of sound stimuli. The transduction of sound waves into electrical signals depends upon mechanosensitive hair bundles that project from the cell's apical surface. Each stereocilium within a hair bundle is composed of uniformly polarized and tightly packed actin filaments. Several stereociliary proteins have been shown to be associated with hair bundle development and function and are known to cause deafness in mice and humans when mutated. The growth of the stereociliar actin core is dynamically regulated at the actin filament barbed ends in the stereociliary tip. We show that Eps8, a protein with actin binding, bundling, and barbed-end capping activities in other systems, is a novel component of the hair bundle. Eps8 is localized predominantly at the tip of the stereocilia and is essential for their normal elongation and function. Moreover, we have found that Eps8 knockout mice are profoundly deaf and that IHCs, but not OHCs, fail to mature into fully functional sensory receptors. We propose that Eps8 directly regulates stereocilia growth in hair cells and also plays a crucial role in the physiological maturation of mammalian cochlear IHCs. Together, our results indicate that Eps8 is critical in coordinating the development and functionality of mammalian auditory hair cells. PMID:21526224

  18. Chrysanthemum zawadskii extract induces hair growth by stimulating the proliferation and differentiation of hair matrix.

    PubMed

    Li, Zheng; Li, Jingjie; Gu, Lijuan; Begum, Shahnaz; Wang, Yunbo; Sun, Baishen; Lee, Mira; Sung, Changkeun

    2014-07-01

    Chrysanthemum zawadskii has been proven to possess hair growth activity and has been used as treatment for hair loss. The aim of this study was to provide a novel explanation of the mechanism by which Chrysanthemum zawadskii extracts (CZe) promote hair growth and to characterize the affected hair follicle (HF) regions and the progression of growth. The n-butanol and water fractions of CZe were used for hair growth induction by topical application to the backs of C57BL/6 mice for up to 30 days. To investigate cell development during HF morphogenesis, bromodeoxyuridine-labeled skin sections were detected using immunohistochemistry. The results showed that the water fraction of CZe promoted hair shaft production and induced premature entry of telogen HFs into the anagen. Subsequently, immunohistochemical studies indicated that the water fraction of CZe stimulated the differentiation and proliferation of pluripotent epidermal matrix cells in the matrix region and epithelial stem cells in the basal layer of the epidermis. Additionally, flavonoids were identified as effective constituents. Therefore, the findings of this study suggested that the water fraction of CZe may be developed as a therapeutic agent for the prevention of hair loss. PMID:24807783

  19. Human TSC2-null fibroblast-like cells induce hair follicle neogenesis and hamartoma morphogenesis.

    PubMed

    Li, Shaowei; Thangapazham, Rajesh L; Wang, Ji-An; Rajesh, Sangeetha; Kao, Tzu-Cheg; Sperling, Leonard; Moss, Joel; Darling, Thomas N

    2011-01-01

    Hamartomas are composed of cells native to an organ but abnormal in number, arrangement or maturity. In the tuberous sclerosis complex (TSC), hamartomas develop in multiple organs because of mutations in TSC1 or TSC2. Here we show that TSC2-null fibroblast-like cells grown from human TSC skin hamartomas induced normal human keratinocytes to form hair follicles and stimulated hamartomatous changes. Follicles were complete with sebaceous glands, hair shafts and inner and outer root sheaths. TSC2-null cells surrounding the hair bulb expressed markers of the dermal sheath and dermal papilla. Tumour xenografts recapitulated characteristics of TSC skin hamartomas with increased mammalian target of the rapamycin complex 1 (mTORC1) activity, angiogenesis, mononuclear phagocytes and epidermal proliferation. Treatment with an mTORC1 inhibitor normalized these parameters and reduced the number of tumour cells. These studies indicate that TSC2-null cells are the inciting cells for TSC skin hamartomas, and suggest that studies on hamartomas will provide insights into tissue morphogenesis and regeneration. PMID:21407201

  20. Hair follicle defects and squamous cell carcinoma formation in Smad4 conditional knockout mouse skin.

    PubMed

    Qiao, W; Li, A G; Owens, P; Xu, X; Wang, X-J; Deng, C-X

    2006-01-12

    Smad4 is the common mediator for TGFbeta signals, which play important functions in many biological processes. To study the role of Smad4 in skin development and epidermal tumorigenesis, we disrupted this gene in skin using the Cre-loxP approach. We showed that absence of Smad4 blocked hair follicle differentiation and cycling, leading to a progressive hair loss of mutant (MT) mice. MT hair follicles exhibited diminished expression of Lef1, and increased proliferative cells in the outer root sheath. Additionally, the skin of MT mice exhibited increased proliferation of basal keratinocytes and epidermal hyperplasia. Furthermore, we provide evidence that the absence of Smad4 resulted in a block of both TGFbeta and bone morphogenetic protein (BMP) signaling pathways, including p21, a well-known cyclin-dependent kinase inhibitor. Consequently, all MT mice developed spontaneous malignant skin tumors from 3 months to 13 months of age. The majority of tumors are malignant squamous cell carcinomas. A most notable finding is that tumorigenesis is accompanied by inactivation of phosphatase and tensin homolog deleted on chromosome 10 (Pten), activation of AKT, fast proliferation and nuclear accumulation of cyclin D1. These observations revealed the essential functions of Smad4-mediated signals in repressing skin tumor formation through the TGFbeta/BMP pathway, which interacts with the Pten signaling pathway. PMID:16170355

  1. Significance of hair-dye base-induced sensory irritation.

    PubMed

    Fujita, F; Azuma, T; Tajiri, M; Okamoto, H; Sano, M; Tominaga, M

    2010-06-01

    Oxidation hair-dyes, which are the principal hair-dyes, sometimes induce painful sensory irritation of the scalp caused by the combination of highly reactive substances, such as hydrogen peroxide and alkali agents. Although many cases of severe facial and scalp dermatitis have been reported following the use of hair-dyes, sensory irritation caused by contact of the hair-dye with the skin has not been reported clearly. In this study, we used a self-assessment questionnaire to measure the sensory irritation in various regions of the body caused by two model hair-dye bases that contained different amounts of alkali agents without dyes. Moreover, the occipital region was found as an alternative region of the scalp to test for sensory irritation of the hair-dye bases. We used this region to evaluate the relationship of sensitivity with skin properties, such as trans-epidermal water loss (TEWL), stratum corneum water content, sebum amount, surface temperature, current perception threshold (CPT), catalase activities in tape-stripped skin and sensory irritation score with the model hair-dye bases. The hair-dye sensitive group showed higher TEWL, a lower sebum amount, a lower surface temperature and higher catalase activity than the insensitive group, and was similar to that of damaged skin. These results suggest that sensory irritation caused by hair-dye could occur easily on the damaged dry scalp, as that caused by skin cosmetics reported previously. PMID:20557579

  2. Coupling a sensory hair-cell bundle to cyber clones enhances nonlinear amplification

    PubMed Central

    Barral, Jérémie; Dierkes, Kai; Lindner, Benjamin; Jülicher, Frank; Martin, Pascal

    2010-01-01

    The vertebrate ear benefits from nonlinear mechanical amplification to operate over a vast range of sound intensities. The amplificatory process is thought to emerge from active force production by sensory hair cells. The mechano-sensory hair bundle that protrudes from the apical surface of each hair cell can oscillate spontaneously and function as a frequency-selective, nonlinear amplifier. Intrinsic fluctuations, however, jostle the response of a single hair bundle to weak stimuli and seriously limit amplification. Most hair bundles are mechanically coupled by overlying gelatinous structures. Here, we assayed the effects of mechanical coupling on the hair-bundle amplifier by combining dynamic force clamp of a hair bundle from the bullfrog’s saccule with real-time stochastic simulations of hair-bundle mechanics. This setup couples the hair bundle to two virtual hair bundles, called cyber clones, and mimics a situation in which the hair bundle is elastically linked to two neighbors with similar characteristics. We found that coupling increased the coherence of spontaneous hair-bundle oscillations. By effectively reducing noise, the synergic interplay between the hair bundle and its cyber clones also enhanced amplification of sinusoidal stimuli. All observed effects of coupling were in quantitative agreement with simulations. We argue that the auditory amplifier relies on hair-bundle cooperation to overcome intrinsic noise limitations and achieve high sensitivity and sharp frequency selectivity. PMID:20404191

  3. PELE'S HAIR: case studies from Kilauea

    NASA Astrophysics Data System (ADS)

    Cannata, C. B.

    2010-12-01

    Pele’s hair are long, thin strands of basaltic volcanic glass formed when small drops of magma are spun or drawn out by the wind or streams of volcanic gas into long hair-like strands. Named for Pele, the Hawaiian goddess of fire, they are basically found in Hawaiian eruption deposits. Pele’s hair is deep yellow or gold and is commonly found downwind from active vents concentrated in hollows or other low energy ‘traps’. In literature the origin of these thin strands of glass have been linked to fountains from Hawaiian eruptions. Beside the high fountaining, Pele’s hair are actually found in other environments. In this work we investigated in detail the dimensions, surface textures and the nature of Pele’s hair, from four typical environment of formation at Hawaiian volcanoes: high fountaining, weak explosive activity, lava ocean entry and a lava skylight. Samples has been characterized in terms of textural and morphological features, in thin section and under the SEM. Pele’s hair consists of long strands of gold sideromelane, showing variable length, from an half mm to tens of mm, often without surface vesicles and sometimes including Pele’s tears inside or at the end. They are often found incomplete, since they are easily broken on landing or even during transport. Their surfaces are mostly rough, with ‘ploughs’ of different sizes and large cavities. Vesicles are visible in the cross sections of Pele’s hair. There are two mostly size population of bubbles: one elongated and central and parallel to the axis of elongation and the other one smaller, and rounded and dispersed across the cross section of the fibers. Pele’s hair often shows, in thin section, a single inner elongate vesicle in the middle of the fragment linked to bubble coalescence phenomena, along the entire length of the hair. Samples from the four volcanic environments show different features in terms of their shape, surface textures and micro-textures, pointing out that

  4. Methanotroph outer membrane preparation.

    PubMed

    Karlsen, Odd A; Berven, Frode S; Jensen, Harald B; Fjellbirkeland, Anne

    2011-01-01

    All presently known methanotrophs are gram-negative bacteria suggesting that they are surrounded by a two-layered membrane: an inner or cytoplasmic membrane and an outer membrane. In the methanotroph Methylococcus capsulatus (Bath), separation of the two membranes has allowed studies on protein and lipid composition of the outer membrane. Its outer membrane can be isolated from purified cell envelopes by selective solubilization of the inner membranes with the detergent Triton X-100. The proteins associated with the outer membrane can further be fractionated into integral and tightly associated proteins and peripheral loosely associated proteins. We present here protocols for this fractionation and show how the proteins associated with the outer leaflet of the outer membrane can be isolated and identified by whole-cell biotin surface labeling. PMID:21419921

  5. Can a topical scalp treatment reduce hair bulb extraction?

    PubMed

    Gruber, James V; Bouldin, Lisa; Lou, Kevin

    2007-01-01

    Generally speaking, when people talk about "hair breakage" they are typically referring to the idea that as they comb or brush their hair, the fibers are elongating and snapping at some weak point in the fiber length. It is well established that as people chemically treat their hair, the keratin proteins are degraded further and the hair become more brittle and susceptible to breakage. For the consumer, hair breakage is registered as hair fibers noted in their comb or brush, and in the drain that they see after a cosmetic treatment. However, a fundamental question that needs to be asked is whether or not the hairs that are seen in the drain are really the result of hair breakage (i.e., a fiber snapping) or are they the result of hairs that are actually being extracted from the scalp by their root bulbs. If the bulk of the hair fibers are actually extracted by the bulb, than it seems somewhat superfluous to try and improve hair strength by improving the exterior of the fiber. The fiber is dead and topical treatments can only smooth, and possibly moisten already established fiber structure and integrity. This paper will attempt to address hair strength by looking at the scalp and follicle as the target for treatment, showing that topical application of a product containing a blend of well-known skin active ingredients can demonstrate potential reductions in hair extractions. An in vivo testing protocol in which 15 voluntary participants with at least 12" hair length were professionally shampooed, and then treated, half-head, with a commercial conditioner, or the same conditioner that contained 5% of a mixture of yeast peptides, fruit acids and green tea polyphenols every day for five days will be discussed. At the beginning and end of the treatment period, the number of hairs that either broke along the fiber, or extracted by the bulb were gathered, separated and counted for both the treated and untreated side of the head. The results of this one-week study

  6. Borrelia burgdorferi outer membrane protein A induces nuclear translocation of nuclear factor-kappa B and inflammatory activation in human endothelial cells.

    PubMed

    Wooten, R M; Modur, V R; McIntyre, T M; Weis, J J

    1996-11-15

    Lyme disease is caused by infection with Borrelia burgdorferi, and is characterized by bacterial persistence and inflammation in a number of host tissues. B. burgdorferi outer surface lipoproteins possess cytokine stimulatory properties that may be responsible for localized inflammation. B. burgdorferi presence is correlated with severity of disease, and the pathology of many tissues, particularly the arthritic joint, is consistent with localized cytokine production. Spirochete invasion of tissues requires interaction with and penetration of vascular endothelium, suggesting endothelial cells may participate in the inflammation of Lyme disease. In this study, outer surface protein A (OspA), a model B. burgdorferi lipoprotein, was found to be a potent stimulant of nuclear factor-kappa B (NF-kappa B) nuclear translocation in human endothelial cells, resulting in nuclear levels similar to those seen in response to known inflammatory mediators. Only the lipid-modified OspA had activity, and activity was not due to contamination with LPS. Nuclear NF-kappa B was detectable within 15 min, suggesting that OspA directly mediates NF-kappa B nuclear translocation. OspA also rapidly up-regulated endothelial cell production of several proteins whose transcription is dependent on NF-kappa B: the cytokine IL-6; the chemokine IL-8; and the adhesion molecules E-selectin, VCAM-1, and ICAM-1. The adhesion molecules were functional, as demonstrated by enhanced binding of neutrophils to OspA-stimulated endothelial monolayers. These data suggest that OspA may initiate synthesis of many proteins essential for localized inflammation via the direct activation of NF-kappa B-dependent transcription. These observations suggest that the interaction of B. burgdorferi lipoproteins with the endothelium may directly induce the inflammation responsible for the symptoms of Lyme disease. PMID:8906837

  7. The Small GTPase ROP10 of Medicago truncatula Is Required for Both Tip Growth of Root Hairs and Nod Factor-Induced Root Hair Deformation

    PubMed Central

    Lei, Ming-Juan; Wang, Qi; Li, Xiaolin; Chen, Aimin; Luo, Li; Xie, Yajun; Li, Guan; Luo, Da; Mysore, Kirankumar S.; Wen, Jiangqi; Xie, Zhi-Ping; Staehelin, Christian; Wang, Yan-Zhang

    2015-01-01

    Rhizobia preferentially enter legume root hairs via infection threads, after which root hairs undergo tip swelling, branching, and curling. However, the mechanisms underlying such root hair deformation are poorly understood. Here, we showed that a type II small GTPase, ROP10, of Medicago truncatula is localized at the plasma membrane (PM) of root hair tips to regulate root hair tip growth. Overexpression of ROP10 and a constitutively active mutant (ROP10CA) generated depolarized growth of root hairs, whereas a dominant negative mutant (ROP10DN) inhibited root hair elongation. Inoculated with Sinorhizobium meliloti, the depolarized swollen and ballooning root hairs exhibited extensive root hair deformation and aberrant infection symptoms. Upon treatment with rhizobia-secreted nodulation factors (NFs), ROP10 was transiently upregulated in root hairs, and ROP10 fused to green fluorescent protein was ectopically localized at the PM of NF-induced outgrowths and curls around rhizobia. ROP10 interacted with the kinase domain of the NF receptor NFP in a GTP-dependent manner. Moreover, NF-induced expression of the early nodulin gene ENOD11 was enhanced by the overexpression of ROP10 and ROP10CA. These data suggest that NFs spatiotemporally regulate ROP10 localization and activity at the PM of root hair tips and that interactions between ROP10 and NF receptors are required for root hair deformation and continuous curling during rhizobial infection. PMID:25794934

  8. The small GTPase ROP10 of Medicago truncatula is required for both tip growth of root hairs and nod factor-induced root hair deformation.

    PubMed

    Lei, Ming-Juan; Wang, Qi; Li, Xiaolin; Chen, Aimin; Luo, Li; Xie, Yajun; Li, Guan; Luo, Da; Mysore, Kirankumar S; Wen, Jiangqi; Xie, Zhi-Ping; Staehelin, Christian; Wang, Yan-Zhang

    2015-03-01

    Rhizobia preferentially enter legume root hairs via infection threads, after which root hairs undergo tip swelling, branching, and curling. However, the mechanisms underlying such root hair deformation are poorly understood. Here, we showed that a type II small GTPase, ROP10, of Medicago truncatula is localized at the plasma membrane (PM) of root hair tips to regulate root hair tip growth. Overexpression of ROP10 and a constitutively active mutant (ROP10CA) generated depolarized growth of root hairs, whereas a dominant negative mutant (ROP10DN) inhibited root hair elongation. Inoculated with Sinorhizobium meliloti, the depolarized swollen and ballooning root hairs exhibited extensive root hair deformation and aberrant infection symptoms. Upon treatment with rhizobia-secreted nodulation factors (NFs), ROP10 was transiently upregulated in root hairs, and ROP10 fused to green fluorescent protein was ectopically localized at the PM of NF-induced outgrowths and curls around rhizobia. ROP10 interacted with the kinase domain of the NF receptor NFP in a GTP-dependent manner. Moreover, NF-induced expression of the early nodulin gene ENOD11 was enhanced by the overexpression of ROP10 and ROP10CA. These data suggest that NFs spatiotemporally regulate ROP10 localization and activity at the PM of root hair tips and that interactions between ROP10 and NF receptors are required for root hair deformation and continuous curling during rhizobial infection. PMID:25794934

  9. Different uptake of gentamicin through TRPV1 and TRPV4 channels determines cochlear hair cell vulnerability.

    PubMed

    Lee, Jeong-Han; Park, Channy; Kim, Se-Jin; Kim, Hyung-Jin; Oh, Gi-Su; Shen, AiHua; So, Hong-Seob; Park, Raekil

    2013-01-01

    Hair cells at the base of the cochlea appear to be more susceptible to damage by the aminoglycoside gentamicin than those at the apex. However, the mechanism of base-to-apex gradient ototoxicity by gentamicin remains to be elucidated. We report here that gentamicin caused rodent cochlear hair cell damages in a time- and dose-dependent manner. Hair cells at the basal turn were more vulnerable to gentamicin than those at the apical turn. Gentamicin-conjugated Texas Red (GTTR) uptake was predominant in basal turn hair cells in neonatal rats. Transient receptor potential vanilloid 1 (TRPV1) and 4 (TRPV4) expression was confirmed in the cuticular plate, stereocilia and hair cell body of inner hair cells and outer hair cells. The involvement of TRPV1 and TRPV4 in gentamicin trafficking of hair cells was confirmed by exogenous calcium treatment and TRPV inhibitors, including gadolinium and ruthenium red, which resulted in markedly inhibited GTTR uptake and gentamicin-induced hair cell damage in rodent and zebrafish ototoxic model systems. These results indicate that the cytotoxic vulnerability of cochlear hair cells in the basal turn to gentamicin may depend on effective uptake of the drug, which was, in part, mediated by the TRPV1 and TRPV4 proteins. PMID:23470714

  10. Effect of ultraviolet radiation, smoking and nutrition on hair.

    PubMed

    Trüeb, Ralph M

    2015-01-01

    Similar to the rest of the skin, the hair is exposed to noxious environmental factors. While ultraviolet radiation (UVR) and smoking are well appreciated as major factors contributing to the extrinsic aging of the skin, their effects on the condition of hair have only lately attracted the attention of the medical community. Terrestrial solar UVR ranges from approximately 290 to 400 nm; UV-B (290-315 nm) reaches only the upper dermis, while the penetration of UV-A (315-400 nm) into the dermis increases with wavelength. The two most important chronic effects of UVR on the skin and bald scalp are photocarcinogenesis and solar elastosis; however, the effects of UVR on hair have largely been ignored. As a consequence of increased leisure time and a growing popularity of outdoor activities and holidays in the sun, the awareness of sun protection of the skin has become important and should also apply to the hair. Besides being the single-most preventable cause of significant cardiovascular and pulmonary morbidity and an important cause of death, the association of tobacco smoking with various adverse effects on the skin and hair has also been recognized. Increasing public awareness of the association between smoking and hair loss seems to offer a good opportunity for the prevention or cessation of smoking, since the appearance of hair plays an important role in the overall physical appearance and self-perception of people. Finally, the quantity and quality of hair are closely related to the nutritional state of an individual. Normal supply, uptake, and transport of proteins, calories, trace elements, and vitamins are of fundamental importance in tissues with high biosynthetic activity, such as the hair follicle. In instances of protein and calorie malnutrition as well as essential amino acid, trace element, and vitamin deficiencies, hair growth and pigmentation may be impaired. Ultimately, important commercial interest lies in the question of whether increasing the

  11. Two-state approach to stochastic hair bundle dynamics

    NASA Astrophysics Data System (ADS)

    Clausznitzer, Diana; Lindner, Benjamin; Jülicher, Frank; Martin, Pascal

    2008-04-01

    Hair cells perform the mechanoelectrical transduction of sound signals in the auditory and vestibular systems of vertebrates. The part of the hair cell essential for this transduction is the so-called hair bundle. In vitro experiments on hair cells from the sacculus of the American bullfrog have shown that the hair bundle comprises active elements capable of producing periodic deflections like a relaxation oscillator. Recently, a continuous nonlinear stochastic model of the hair bundle motion [Nadrowski , Proc. Natl. Acad. Sci. U.S.A. 101, 12195 (2004)] has been shown to reproduce the experimental data in stochastic simulations faithfully. Here, we demonstrate that a binary filtering of the hair bundle's deflection (experimental data and continuous hair bundle model) does not change significantly the spectral statistics of the spontaneous as well as the periodically driven hair bundle motion. We map the continuous hair bundle model to the FitzHugh-Nagumo model of neural excitability and discuss the bifurcations between different regimes of the system in terms of the latter model. Linearizing the nullclines and assuming perfect time-scale separation between the variables we can map the FitzHugh-Nagumo system to a simple two-state model in which each of the states corresponds to the two possible values of the binary-filtered hair bundle trajectory. For the two-state model, analytical expressions for the power spectrum and the susceptibility can be calculated [Lindner and Schimansky-Geier, Phys. Rev. E 61, 6103 (2000)] and show the same features as seen in the experimental data as well as in simulations of the continuous hair bundle model.

  12. Aging hair follicles rejuvenated by transplantation to a young subcutaneous environment.

    PubMed

    Cao, Wenluo; Li, Lingna; Kajiura, Satoshi; Amoh, Yasuyuki; Tan, Yuying; Liu, Fang; Hoffman, Robert M

    2016-04-17

    We demonstrate in the present study that young host mice rejuvenate aged hair follicles after transplantation. Young mice promote the hair shaft growth of transplanted old hair follicles, as well as young follicles, in contrast to old host mice, which did not support hair-shaft growth from transplanted old or young follicles. Nestin-expressing hair follicle-associated pluripotent (HAP) stem cells of transplanted old and young hair follicles remained active in young host nude mice. In contrast, the nestin-expressing HAP stem cells in young and old hair follicles transplanted to old nude mice were not as active as in young nude host mice. The present study shows that transplanted old hair follicles were rejuvenated by young host mice, suggesting that aging may be reversible. PMID:26940664

  13. Characterization of Pseudomonas aeruginosa LpxT reveals dual positional lipid A kinase activity and coordinated control of outer membrane modification

    PubMed Central

    Nowicki, Emily M.; O’Brien, John P.; Brodbelt, Jennifer S.; Trent, M. Stephen

    2014-01-01

    Summary Gram-negative bacteria have evolved modification machinery to promote a dynamic outer membrane in response to a continually fluctuating environment. The kinase LpxT, for example, adds a phosphate group to the lipid A moiety of some Gram-negatives including Escherichia coli and Salmonella enterica. LpxT activity is inhibited under conditions that compromise membrane integrity, resulting instead in the addition of positively charged groups to lipid A that increase membrane stability and provide resistance to cationic antimicrobial peptides. We have now identified a functional lpxT ortholog in P. aeruginosa. LpxTPa has unique enzymatic characteristics, as it is able to phosphorylate P. aeruginosa lipid A at two sites of the molecule. Surprisingly, a previously uncharacterized lipid A 4′-dephospho-1-triphosphate species was detected. LpxTPa activity is inhibited by magnesium independently of lpxTPa transcription. Modulation of LpxTPa activity is influenced by transcription of the lipid A aminoarabinose transferase ArnT, known to be activated in response to limiting magnesium. These results demonstrate a divergent activity of LpxTPa, and suggest the existence of a coordinated regulatory mechanism that permits adaptation to a changing environment. PMID:25223756

  14. Excessive or unwanted hair in women

    MedlinePlus

    Hypertrichosis; Hirsutism; Hair - excessive (women); Excessive hair in women; Hair - women - excessive or unwanted ... much of this hormone, you may have unwanted hair growth. In most cases, the exact cause is ...

  15. Aging changes in hair and nails

    MedlinePlus

    ... of aging. Hair color is due to a pigment called melanin , which hair follicles produce. Follicles are ... slows. Hair strands become smaller and have less pigment. So the thick, coarse hair of a young ...

  16. Expression of amelogenin and effects of cyclosporin A in developing hair follicles in rats.

    PubMed

    Yoo, Hong-Il; Lee, Gye-Hyeok; Lee, Su-Young; Kang, Jee-Hae; Moon, Jung-Sun; Kim, Min-Seok; Kim, Sun-Hun

    2016-01-01

    Amelogenin, an enamel matrix protein has been considered to be exclusively expressed by ameloblasts during odontogenesis. However, burgeoning evidence indicates that amelogenin is also expressed in non-mineralizing tissues. Under the hypothesis that amelogenin may be a functional molecule in developing hair follicles which share developmental features with odontogenesis, this study for the first time elucidated the presence and functional changes of amelogenin and its receptors during rat hair follicle development. Amelogenin was specifically localized in the outer epithelial root sheath of hair follicles. Its expression appeared in the deeper portion of hair follicles, i.e. the bulbar and suprabulbar regions rather than the superficial region. Lamp-1, an amelogenin receptor, was localized in either follicular cells or outer epithelial sheath cells, reflecting functional changes during development. The expression of amelogenin splicing variants increased in a time-dependent manner during postnatal development of hair follicles. Amelogenin expression was increased by treatment with cyclosporin A, which is an inducer of anagen in the hair follicle, whereas the level of Lamp-1 and -2 was decreased by cyclosporin A treatment. These results suggest that amelogenin may be a functional molecule involved in the development of the hair follicle rather than an inert hair shaft matrix protein. PMID:26426935

  17. The biology of hair diversity.

    PubMed

    Westgate, Gillian E; Botchkareva, Natalia V; Tobin, Desmond J

    2013-08-01

    Hair diversity, its style, colour, shape and growth pattern is one of our most defining characteristics. The natural versus temporary style is influenced by what happens to our hair during our lifetime, such as genetic hair loss, sudden hair shedding, greying and pathological hair loss in the various forms of alopecia because of genetics, illness or medication. Despite the size and global value of the hair care market, our knowledge of what controls the innate and within-lifetime characteristics of hair diversity remains poorly understood. In the last decade, drivers of knowledge have moved into the arena of genetics where hair traits are obvious and measurable and genetic polymorphisms are being found that raise valuable questions about the biology of hair growth. The recent discovery that the gene for trichohyalin contributes to hair shape comes as no surprise to the hair biologists who have believed for 100 years that hair shape is linked to the structure and function of the inner root sheath. Further conundrums awaiting elucidation include the polymorphisms in the androgen receptor (AR) described in male pattern alopecia whose location on the X chromosome places this genetic contributor into the female line. The genetics of female hair loss is less clear with polymorphisms in the AR not associated with female pattern hair loss. Lifestyle choices are also implicated in hair diversity. Greying, which also has a strong genetic component, is often suggested to have a lifestyle (stress) influence and hair follicle melanocytes show declining antioxidant protection with age and lowered resistance to stress. It is likely that hair research will undergo a renaissance on the back of the rising information from genetic studies as well as the latest contributions from the field of epigenetics. PMID:23363384

  18. The goya mouse mutant reveals distinct newly identified roles for MAP3K1 in the development and survival of cochlear sensory hair cells

    PubMed Central

    Parker, Andrew; Cross, Sally H.; Jackson, Ian J.; Hardisty-Hughes, Rachel; Morse, Susan; Nicholson, George; Coghill, Emma; Bowl, Michael R.; Brown, Steve D. M.

    2015-01-01

    ABSTRACT Mitogen-activated protein kinase, MAP3K1, plays an important role in a number of cellular processes, including epithelial migration during eye organogenesis. In addition, studies in keratinocytes indicate that MAP3K1 signalling through JNK is important for actin stress fibre formation and cell migration. However, MAP3K1 can also act independently of JNK in the regulation of cell proliferation and apoptosis. We have identified a mouse mutant, goya, which exhibits the eyes-open-at-birth and microphthalmia phenotypes. In addition, these mice also have hearing loss. The goya mice carry a splice site mutation in the Map3k1 gene. We show that goya and kinase-deficient Map3k1 homozygotes initially develop supernumerary cochlear outer hair cells (OHCs) that subsequently degenerate, and a progressive profound hearing loss is observed by 9 weeks of age. Heterozygote mice also develop supernumerary OHCs, but no cellular degeneration or hearing loss is observed. MAP3K1 is expressed in a number of inner-ear cell types, including outer and inner hair cells, stria vascularis and spiral ganglion. Investigation of targets downstream of MAP3K1 identified an increase in p38 phosphorylation (Thr180/Tyr182) in multiple cochlear tissues. We also show that the extra OHCs do not arise from aberrant control of proliferation via p27KIP1. The identification of the goya mutant reveals a signalling molecule involved with hair-cell development and survival. Mammalian hair cells do not have the ability to regenerate after damage, which can lead to irreversible sensorineural hearing loss. Given the observed goya phenotype, and the many diverse cellular processes that MAP3K1 is known to act upon, further investigation of this model might help to elaborate upon the mechanisms underlying sensory hair cell specification, and pathways important for their survival. In addition, MAP3K1 is revealed as a new candidate gene for human sensorineural hearing loss. PMID:26542706

  19. Dermatotoxicologic clinical solutions: hair dying in hair dye allergic patients?

    PubMed

    Edwards, Ashley; Coman, Garrett; Blickenstaff, Nicholas; Maibach, Howard

    2015-03-01

    This article describes how to identify allergic contact dermatitis resulting from hair dye, and outlines interventions and prevention principles for those who wish to continue dyeing their hair despite being allergic. Hair dye chemicals thought to be the most frequent sensitizers are discussed with instructions for health care providers on how to counsel patients about techniques to minimize exposure to allergenic substances. This framework should allow many patients to continue dyeing their hair without experiencing adverse side effects. PMID:24754409

  20. The Outer Limits: English.

    ERIC Educational Resources Information Center

    Tyler, Barbara R.; Biesekerski, Joan

    The Quinmester course "The Outer Limits" involves an exploration of unknown worlds, mental and physical, through fiction and nonfiction. Its purpose is to focus attention on the ongoing conquest of the frontiers of the mind, the physical world, and outer space. The subject matter includes identification and investigation of unknown worlds in the…

  1. Pharmacologic inhibition of JAK-STAT signaling promotes hair growth

    PubMed Central

    Harel, Sivan; Higgins, Claire A.; Cerise, Jane E.; Dai, Zhenpeng; Chen, James C.; Clynes, Raphael; Christiano, Angela M.

    2015-01-01

    Several forms of hair loss in humans are characterized by the inability of hair follicles to enter the growth phase (anagen) of the hair cycle after being arrested in the resting phase (telogen). Current pharmacologic therapies have been largely unsuccessful in targeting pathways that can be selectively modulated to induce entry into anagen. We show that topical treatment of mouse and human skin with small-molecule inhibitors of the Janus kinase (JAK)–signal transducer and activator of transcription (STAT) pathway results in rapid onset of anagen and subsequent hair growth. We show that JAK inhibition regulates the activation of key hair follicle populations such as the hair germ and improves the inductivity of cultured human dermal papilla cells by controlling a molecular signature enriched in intact, fully inductive dermal papillae. Our findings open new avenues for exploration of JAK-STAT inhibition for promotion of hair growth and highlight the role of this pathway in regulating the activation of hair follicle stem cells. PMID:26601320

  2. Pharmacologic inhibition of JAK-STAT signaling promotes hair growth.

    PubMed

    Harel, Sivan; Higgins, Claire A; Cerise, Jane E; Dai, Zhenpeng; Chen, James C; Clynes, Raphael; Christiano, Angela M

    2015-10-01

    Several forms of hair loss in humans are characterized by the inability of hair follicles to enter the growth phase (anagen) of the hair cycle after being arrested in the resting phase (telogen). Current pharmacologic therapies have been largely unsuccessful in targeting pathways that can be selectively modulated to induce entry into anagen. We show that topical treatment of mouse and human skin with small-molecule inhibitors of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway results in rapid onset of anagen and subsequent hair growth. We show that JAK inhibition regulates the activation of key hair follicle populations such as the hair germ and improves the inductivity of cultured human dermal papilla cells by controlling a molecular signature enriched in intact, fully inductive dermal papillae. Our findings open new avenues for exploration of JAK-STAT inhibition for promotion of hair growth and highlight the role of this pathway in regulating the activation of hair follicle stem cells. PMID:26601320

  3. Moss hair water transport

    NASA Astrophysics Data System (ADS)

    Pan, Zhao; Wu, Nan; Hurd, Randy; Thomson, Scott; Pitt, William; Truscott, Tadd

    2013-11-01

    We present an investigation of water transportation on a moss (Syntrichia caninervis) indigenous to temperate deserts. The moss typically appears to be in a dry, brown state, but is rehydrated by water during the wet season, making the desert green. Small hairs (500-2000 μm in length, and 40 μm in diameter, d) growing out from the tip of the moss leaves transport water back to the leaves. Through high speed observations and mathematical modeling it appears that this transportation is driven by two different mechanisms. 1) Droplet transport is achieved in three ways: i) A large (10d) droplet attached between two intersecting fibers will move toward the bases of the leaves by the changing angle between the two hairs. ii) The shape of the moss hair is conical, thicker at the base, producing a gradient that moves fluid (5d) toward the leaf similar to cactus spines. iii) We also observe that in some cases a Plateau-Rayleigh instability trigger a series of droplets moving toward the base. 2) Micro-grooves on the moss hair transport a film of water along the moss hair when larger droplets are not available. These various water transportation strategies combine to help the moss to survive in the desert and provide valuable insight.

  4. 76 FR 11811 - Environmental Document Prepared in Support of Oil and Gas Activities on the Alaska Outer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-03

    ... Register (FR) which lists all EAs and FONSIs prepared for OCS permitting activities in the Region during...)). If no EAs and FONSIs were prepared for a 3-month period, no FR Notice is required.'' BOEMRE prepares... FONSI ION Geophysical, Inc., Beaufort and Beaufort Sea and Chukchi Conduct 2D Seismic Survey......

  5. 75 FR 54372 - BOEMRE Information Collection Activity: 1010-0081, Operations in the Outer Continental Shelf for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-07

    ... Bureau of Ocean Energy Management, Regulation, and Enforcement BOEMRE Information Collection Activity..., Extension of a Collection; Comment Request AGENCY: Bureau of Ocean Energy Management, Regulation, and... . Mail or hand-carry comments to the Department of the Interior; Bureau of Ocean Energy...

  6. Potential of Active-Steering Bogie for Reducing Lateral Axle Load Caused at Worn Welded Joints of Outer Rail in Curved Track

    NASA Astrophysics Data System (ADS)

    Iizuka, Tatsuya; Tanifuji, Katsuya; Soma, Hitoshi

    This paper deals with the potential of an active-steering bogie to reduce the large lateral axle load that arises at worn welded joints of the outer rail in a curved track when high-speed trains pass. The shape of the worn joint, called lateral ‘angular bent’, is modeled on the basis of the measured irregularity shape of actual joints. Then, numerical simulation of running on a curved track is carried out for a two-axle bogie vehicle to compare an active-steering bogie and a conventional nonsteering bogie. The behavior of the vehicle negotiating the curve is evaluated from the viewpoints of decreasing the peak value of lateral axle load within the allowance limit and maintaining the running stability. To satisfy the requirements, wheelset-supporting parameters and feedback gains for active-steering are optimized on a curved section of 400 m radius by the Genetic Algorithm. On the basis of the optimized wheelset-supporting parameter values, additional sets of feedback gains, which are adjusted for the curves of different radii, are proposed. The numerical simulation shows that the operation speed of a vehicle with active-steering bogies having the optimized parameter values has the potential to be raised to the possible speed for tilting trains while satisfying the criterion of riding comfort.

  7. Evaluation of hair humidity resistance/moisturization from hair elasticity.

    PubMed

    Gao, Timothy

    2007-01-01

    Average water regain and hair elasticity (Young's modulus) of virgin dark brown and bleached hair fibers under different relative humidity (RH) were determined. It is observed that hair water regain increases linearly with an increase in RH in the range of 40-85%; and the remaining percent of hair elasticity decreases linearly with an increase in RH in the range of 50-80%. Therefore, measurements of average hair elasticity at 50% and 80% RH, respectively, under various equilibrium times before and after cosmetic treatments can be used to evaluate effects of cosmetic treatments on water adsorption behavior of hair-improvement in hair humidity resistance or enhancement in hair moisture uptake. A Hair Humidity Resistance Factor (H(2)RF) has been defined. If R(2)HF > 1, the product improves hair humidity resistance-anti-frizz; if R(2)HF < 1, the product enhances hair water adsorption; when R(2)HF approximately 1, the product has no significant effect on hair water adsorption behavior. This method was applied to evaluate anti-frizz performance of several shampoo formulations containing Polyquaternium-10, or Polyquaternium-70, or Polyquaternium-67, or Guar Hydroxypropyltrimonium Chloride. It was found PQ-70 shampoo showed the highest H(2)RF value and the best anti-frizz performance among these tested shampoos. The results were consistent with those obtained from Image Analysis. PMID:17728940

  8. Today's Hair Style Could Cause Tomorrow's Hair Loss

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_158581.html Today's Hair Style Could Cause Tomorrow's Hair Loss Black women who prefer scalp-pulling hairdos ... News) -- Black women who like to wear their hair pulled back tightly may be increasing their risk ...

  9. Today's Hair Style Could Cause Tomorrow's Hair Loss

    MedlinePlus

    ... nih.gov/medlineplus/news/fullstory_158581.html Today's Hair Style Could Cause Tomorrow's Hair Loss Black women who prefer scalp-pulling hairdos ... News) -- Black women who like to wear their hair pulled back tightly may be increasing their risk ...

  10. Causes of hair loss and the developments in hair rejuvenation.

    PubMed

    Rushton, D H; Norris, M J; Dover, R; Busuttil, Nina

    2002-02-01

    Hair is considered to be a major component of an individual's general appearance. The psychological impact of hair loss results in a measurably detrimental change in self-esteem and is associated with images of reduced worth. It is not surprising that both men and women find hair loss a stressful experience. Genetic hair loss is the major problem affecting men and by the age of 50, up to 50% will be affected. Initial attempts to regenerate the lost hair have centred on applying a topical solution of between 2% to 5% minoxidil; however, the results proved disappointing. Recently, finasteride, a type II 5alpha reductase inhibitor has been found to regrow a noticeable amount of hair in about 40% of balding men. Further developments in treatments have lead to the use of a dual type I and type II inhibitor where 90% of those treated regrow a noticeable amount of hair. In women the major cause of hair loss before the age of 50 is nutritional, with 30% affected. Increased and persistent hair shedding (chronic telogen effluvium) and reduced hair volume are the principle changes occurring. The main cause appears to be depleted iron stores, compromised by a suboptimal intake of the essential amino acid l-lysine. Correction of these imbalances stops the excessive hair loss and returns the hair back to its former glory. However, it can take many months to redress the situation. PMID:18498491

  11. Electrical tuning and transduction in short hair cells of the chicken auditory papilla

    PubMed Central

    Tan, Xiaodong; Beurg, Maryline; Hackney, Carole; Mahendrasingam, Shanthini

    2013-01-01

    The avian auditory papilla contains two classes of sensory receptor, tall hair cells (THCs) and short hair cells (SHCs), the latter analogous to mammalian outer hair cells with large efferent but sparse afferent innervation. Little is known about the tuning, transduction, or electrical properties of SHCs. To address this problem, we made patch-clamp recordings from hair cells in an isolated chicken basilar papilla preparation at 33°C. We found that SHCs are electrically tuned by a Ca2+-activated K+ current, their resonant frequency varying along the papilla in tandem with that of the THCs, which also exhibit electrical tuning. The tonotopic map for THCs was similar to maps previously described from auditory nerve fiber measurements. SHCs also possess an A-type K+ current, but electrical tuning was observed only at resting potentials positive to −45 mV, where the A current is inactivated. We predict that the resting potential in vivo is approximately −40 mV, depolarized by a standing inward current through mechanotransducer (MT) channels having a resting open probability of ∼0.26. The resting open probability stems from a low endolymphatic Ca2+ concentration (0.24 mM) and a high intracellular mobile Ca2+ buffer concentration, estimated from perforated-patch recordings as equivalent to 0.5 mM BAPTA. The high buffer concentration was confirmed by quantifying parvalbumin-3 and calbindin D-28K with calibrated postembedding immunogold labeling, demonstrating >1 mM calcium-binding sites. Both proteins displayed an apex-to-base gradient matching that in the MT current amplitude, which increased exponentially along the papilla. Stereociliary bundles also labeled heavily with antibodies against the Ca2+ pump isoform PMCA2a. PMID:23365177

  12. Myc and Fgf Are Required for Zebrafish Neuromast Hair Cell Regeneration

    PubMed Central

    Obholzer, Nikolaus D.; Sun, Shan; Li, Wenyan; Petrillo, Marco; Dai, Pu; Zhou, Yi; Cotanche, Douglas A.; Megason, Sean G.; Li, Huawei; Chen, Zheng-Yi

    2016-01-01

    Unlike mammals, the non-mammalian vertebrate inner ear can regenerate the sensory cells, hair cells, either spontaneously or through induction after hair cell loss, leading to hearing recovery. The mechanisms underlying the regeneration are poorly understood. By microarray analysis on a chick model, we show that chick hair cell regeneration involves the activation of proliferation genes and downregulation of differentiation genes. Both MYC and FGF are activated in chick hair cell regeneration. Using a zebrafish lateral line neuromast hair cell regeneration model, we show that the specific inhibition of Myc or Fgf suppresses hair cell regeneration, demonstrating that both pathways are essential to the process. Rapid upregulation of Myc and delayed Fgf activation during regeneration suggest a role of Myc in proliferation and Fgf in differentiation. The dorsal-ventral pattern of fgfr1a in the neuromasts overlaps with the distribution of hair cell precursors. By laser ablation, we show that the fgfr1a-positive supporting cells are likely the hair cell precursors that directly give rise to new hair cells; whereas the anterior-posterior fgfr1a-negative supporting cells have heightened proliferation capacity, likely to serve as more primitive progenitor cells to replenish lost precursors after hair cell loss. Thus fgfr1a is likely to mark compartmentalized supporting cell subtypes with different capacities in renewal proliferation and hair cell regeneration. Manipulation of c-MYC and FGF pathways could be explored for mammalian hair cell regeneration. PMID:27351484

  13. Aggregatibacter actinomycetemcomitans Outer Membrane Vesicles Are Internalized in Human Host Cells and Trigger NOD1- and NOD2-Dependent NF-κB Activation

    PubMed Central

    Thay, Bernard; Damm, Anna; Kufer, Thomas A.; Wai, Sun Nyunt

    2014-01-01

    Aggregatibacter actinomycetemcomitans is an oral and systemic pathogen associated with aggressive forms of periodontitis and with endocarditis. We recently demonstrated that outer membrane vesicles (OMVs) disseminated by A. actinomycetemcomitans could deliver multiple proteins, including biologically active cytolethal distending toxin (CDT), into the cytosol of HeLa cells and human gingival fibroblasts (HGF). In the present work, we have used immunoelectron and confocal microscopy analysis and fluorescently labeled vesicles to further investigate mechanisms for A. actinomycetemcomitans OMV-mediated delivery of bacterial antigens to these host cells. Our results supported that OMVs were internalized into the perinuclear region of HeLa cells and HGF. Colocalization analysis revealed that internalized OMVs colocalized with the endoplasmic reticulum and carried antigens, detected using an antibody specific to whole A. actinomycetemcomitans serotype a cells. Consistent with OMV internalization mediating intracellular antigen exposure, the vesicles acted as strong inducers of cytoplasmic peptidoglycan sensor NOD1- and NOD2-dependent NF-κB activation in human embryonic kidney cells. Moreover, NOD1 was the main sensor of OMV-delivered peptidoglycan in myeloid THP1 cells, contributing to the overall inflammatory responses induced by the vesicles. This work reveals a role of A. actinomycetemcomitans OMVs as a trigger of innate immunity via carriage of NOD1- and NOD2-active pathogen-associated molecular patterns (PAMPs). PMID:25024364

  14. Future horizons in hair restoration.

    PubMed

    Marshall, Bryan T; Ingraham, Chris A; Wu, Xunwei; Washenik, Ken

    2013-08-01

    This article reviews the history of hair follicle regeneration from follicular fragments and dissociated cells. The challenges of trichogenic in vitro culture and subsequent delivery into the patient are discussed, as well as cosmetic acceptance, recent achievements on regeneration of human hair follicles, and new potential cell sources for hair regeneration. PMID:24017993

  15. Hair follicle targeting, penetration enhancement and Langerhans cell activation make cyanoacrylate skin surface stripping a promising delivery technique for transcutaneous immunization with large molecules and particle-based vaccines.

    PubMed

    Vogt, Annika; Hadam, Sabrina; Deckert, Iliane; Schmidt, Julia; Stroux, Andrea; Afraz, Zahra; Rancan, Fiorenza; Lademann, Jürgen; Combadiere, Behazine; Blume-Peytavi, Ulrike

    2015-01-01

    Transcutaneous immunization (TCI) requires targeting of a maximum number of skin antigen-presenting cells as non-invasive as possible on small skin areas. In two clinical trials, we introduced cyanoacrylate skin surface stripping (CSSS) as a safe method for TCI. Here, using ex vivo human skin, we demonstrate that one CSSS procedure removed only 30% of stratum corneum, but significantly increased the penetration of 200 nm polystyrene particles deep into vellus and intermediate hair follicles from where they could not been retrieved by conventional tape stripping. Two subsequent CSSS had no striking additional effect. CSSS increased particle penetration in superficial stratum corneum and induced Langerhans cell activation. Formulation in amphiphilic ointment or massage did not substantially influences the interfollicular penetration profiles. Hair follicle (HF) targeting by CSSS could become a highly effective tool for TCI when combined with carrier-based delivery and is gaining new attention as our understanding on the HF immune system increases. PMID:25382068

  16. Complications in hair-restoration surgery.

    PubMed

    Konior, Raymond J

    2013-08-01

    Most complications associated with hair restoration are completely preventable and arise from variables that are directly controlled by the surgeon and the patient. Physicians who thoroughly grasp the nuances of modern surgical techniques and fully understand the physiologic dynamics of the balding process are least likely to generate a physician-controlled error. Highly motivated, well-educated patients who carefully follow instructions and take an active role in the postoperative recovery process minimize the chance of patient-controlled errors. This article discusses potential complications associated with surgical hair restoration, and the roles of the patient and physician in minimizing the risk of complications. PMID:24017992

  17. The 'follicular trochanter': an epithelial compartment of the human hair follicle bulge region in need of further characterization.

    PubMed

    Tiede, S; Kloepper, J E; Whiting, D A; Paus, R

    2007-11-01

    Recent articles on hair follicle stem cells have summarized the current state of knowledge of what has been termed the hair follicle 'bulge'. During the course of immunohistological studies aimed at characterizing the expression of selected extracellular matrix proteins in the - as yet insufficiently characterized - niche of human bulge hair follicle stem cells, we have recently come across a largely forgotten, peculiar epithelial protrusion of the outer root sheath, which was visible in only a minority of all examined hair follicles. The morphology and immunoreactivity patterns of this structure, the 'follicular trochanter', are described herein. PMID:17714535

  18. Study of hair shine and hair surface smoothness.

    PubMed

    Gao, Timothy; Pereira, Abel; Zhu, Sam

    2009-01-01

    A new hair visual appearance measurement system called SAMBA from Bossa Nova Technologies (Venice, CA) has been employed to measure effects of cosmetic treatments on hair shine and surface smoothness of different types of hair samples. Experimental procedures for evaluations of shine value and surface cuticle angle of hair samples treated with rinse-off products (shampoo or/and conditioner) have been successfully established and applied. We demonstrated that hair spray and conditioner formulas containing PPG-3 benzyl ether myristate (PBEM) (1) showed great performance on shine enhancement for hairs with light and medium colors. Instrumental measurement of shine values was also conducted to compare different commercial shampoo and conditioner products. This study showed reliable utility of SAMBA system and demonstrated the shine enhancement of PBEM in hair care. PMID:19450419

  19. Hair shafts in trichoscopy: clues for diagnosis of hair and scalp diseases.

    PubMed

    Rudnicka, Lidia; Rakowska, Adriana; Kerzeja, Marta; Olszewska, Małgorzata

    2013-10-01

    Trichoscopy (hair and scalp dermoscopy) analyzes the structure and size of growing hair shafts, providing diagnostic clues for inherited and acquired causes of hair loss. Types of hair shaft abnormalities observed include exclamation mark hairs (alopecia areata, trichotillomania, chemotherapy-induced alopecia), Pohl-Pinkus constrictions (alopecia areata, chemotherapy-induced alopecia, blood loss, malnutrition), comma hairs (tinea capitis), corkscrew hairs (tinea capitis), coiled hairs (trichotillomania), flame hairs (trichotillomania), and tulip hairs (in trichotillomania, alopecia areata). Trichoscopy allows differential diagnosis of most genetic hair shaft disorders. This article proposes a classification of hair shaft abnormalities observed by trichoscopy. PMID:24075554

  20. Bering Sea summary report: Outer Continental Shelf oil and gas activities in the Bering Sea and their onshore impacts

    SciTech Connect

    Deis, J.; Pierson, R.; Kurz, F.

    1983-09-01

    Two federal offshore oil-and-gas lease sales have been held in the Bering Sea Subregion. Lease Sale 57, Norton Basin, was held on March 15, 1983. Lease Sale 70, St. George Basin, was held on April 12, 1983. The sale offered 479 tracts, of which 97 received bids. The Department of the Interior has indicated that it will accept 96 of the 97 high bids; however, to date, leases have not been awarded. The Department of the Interior was enjoined from issuing leases by the US District Court of Alaska because of possible impacts from postlease preliminary seismic activities on gray and right whales. In accordance with the Court's ruling, leases cannot be issued until the completion of a supplemental environmental impact statement, which is anticipated to occur in November 1983. Six lease offerings in the Bering Sea Subregion are scheduled through 1987. Six deep stratigraphic test wells are the only wells drilled to date in the Bering Sea Subregion. To date, oil companies have not submitted exploration plans for the Norton Basin Planning Area. Exploration in Norton Basin could begin in the summer of 1984, at the earliest. Exploration plans cannot be submitted for the St. George Basin Planning Area until the leases are awarded. At this time, various onshore areas are being considered as possible support bases for offshore oil-and-gas exploration. At this stage, before exploratory drilling has occurred and in the absence of a commercial discovery, plans for transporting petroleum from the Bering Sea to markets in the United States are unclear. The current estimates of risked resources for lands leased in Lease Sale 57, Norton Basin, are 33 million barrels of oil and 110 billion cubic feet of gas. Lease Sale 70, St. George Basin, estimates of risked resources for leased lands are 27 million barrels of oil and 310 billion cubic feet of gas. 55 references, 10 figures, 3 tables.

  1. Outer Solar System Nomenclature

    NASA Technical Reports Server (NTRS)

    Owen, Tobias C.; Grant, John (Technical Monitor)

    2003-01-01

    This grant has supported work by T. Owen and B. A. Smith on planetary and satellite nomenclature, carried out under the general auspices of the International Astronomical Union (IAU). The IAU maintains a Working Group on Planetary and Satellite Nomenclature (WGPSN) whose current chair is Prof.Kaare Aksnes of the Rosseland Institute for Theoretical Astrophysics in Oslo, Norway. Both Owen and Smith are members of the WGPSN; Owen as chair of the Outer Solar System Task Group, and Smith as chair of the Mars Task Group. The major activity during the last grant period (2002) was the approval of several new names for features on Mars by Smith's group and features on Jovian satellites plus new names for satellites of Jupiter, Saturn and Uranus by Owen's group. Much of this work was accomplished by e-mail exchanges, but the new nomenclature was formally discussed and approved at a meeting of the WGPSN held in conjunction with the Division for Planetary Sciences meeting in Birmingham, Alabama in October 2002.

  2. Campylobacter jejuni outer membrane vesicle-associated proteolytic activity promotes bacterial invasion by mediating cleavage of intestinal epithelial cell E-cadherin and occludin.

    PubMed

    Elmi, Abdi; Nasher, Fauzy; Jagatia, Heena; Gundogdu, Ozan; Bajaj-Elliott, Mona; Wren, Brendan; Dorrell, Nick

    2016-04-01

    Outer membrane vesicles (OMVs) play an important role in the pathogenicity of Gram-negative bacteria. Campylobacter jejuni produces OMVs that trigger IL-8, IL-6, hBD-3 and TNF-α responses from T84 intestinal epithelial cells and are cytotoxic to Caco-2 IECs and Galleria mellonella larvae. Proteomic analysis of 11168H OMVs identified the presence of three proteases, HtrA, Cj0511 and Cj1365c. In this study, 11168H OMVs were shown to possess proteolytic activity that was reduced by pretreatment with specific serine protease inhibitors. OMVs isolated from 11168H htrA, Cj0511 or Cj1365c mutants possess significantly reduced proteolytic activity. 11168H OMVs are able to cleave both E-cadherin and occludin, but this cleavage is reduced with OMVs pretreated with serine protease inhibitors and also with OMVs isolated from htrA or Cj1365c mutants. Co-incubation of T84 monolayers with 11168H OMVs results in a visible reduction in both E-cadherin and occludin. The addition of 11168H OMVs to the co-culture of live 11168H bacteria with T84 cells results in enhanced levels of bacterial adhesion and invasion in a time-dependent and dose-dependent manner. Further investigation of the cleavage of host cell structural proteins by C. jejuni OMVs should enhance our understanding of the interactions of this important pathogen with intestinal epithelial cells. PMID:26451973

  3. Advances in Understanding Hair Growth

    PubMed Central

    Bernard, Bruno A.

    2016-01-01

    In this short review, I introduce an integrated vision of human hair follicle behavior and describe opposing influences that control hair follicle homeostasis, from morphogenesis to hair cycling. The interdependence and complementary roles of these influences allow us to propose that the hair follicle is a true paradigm of a “Yin Yang” type, that is a cold/slow-hot/fast duality. Moreover, a new promising field is emerging, suggesting that glycans are key elements of hair follicle growth control. PMID:26918186

  4. Hair dye poisoning

    MedlinePlus

    ... temporary dyes are: Arsenic Bismuth Denatured alcohol Lead ( lead poisoning ) Mercury Pyrogallol Silver Hair dyes may contain other ... infection. Continued exposure to lead or mercury can lead to permanent brain and nervous system damage. Alternative ... References Lee DC. Hydrocarbons. In: Marx JA, Hockberger ...

  5. Outer planet satellites

    SciTech Connect

    Schenk, P.M. )

    1991-01-01

    Recent findings on the outer-planet satellites are presented, with special consideration given to data on the rheologic properties of ice on icy satellites, the satellite surfaces and exogenic processes, cratering on dead cratered satellites, volcanism, and the interiors of outer-planet satellites. Particular attention is given to the state of Titan's surface and the properties of Triton, Pluto, and Charon. 210 refs.

  6. Hair as a Biomarker of Environmental Manganese Exposure

    PubMed Central

    Eastman, Rachel R.; Jursa, Tom P.; Benedetti, Chiara; Lucchini, Roberto G.; Smith, Donald R.

    2013-01-01

    The absence of well-validated biomarkers of manganese (Mn) exposure in children remains a major obstacle for studies of Mn toxicity. We developed a hair cleaning methodology to establish the utility of hair as an exposure biomarker for Mn and other metals (Pb, Cr, Cu), using ICP-MS, scanning electron microscopy, and laser ablation ICP-MS to evaluate cleaning efficacy. Exogenous metal contamination on hair that was untreated or intentionally contaminated with dust or Mn-contaminated water was effectively removed using a cleaning method of 0.5% Triton X-100 sonication plus 1N nitric acid sonication. This cleaning method was then used on hair samples from children (n=121) in an ongoing study of environmental Mn exposure and related health effects. Mean hair Mn levels were 0.121 μg/g (median = 0.073 μg/g, range = 0.011 – 0.736 μg/g), which are ~4 to 70-fold lower than levels reported in other pediatric Mn studies. Hair Mn levels were also significantly higher in children living in the vicinity of active, but not historic, ferroalloy plant emissions compared to controls (P<0.001). These data show that exogenous metal contamination on hair can be effectively cleaned of exogenous metal contamination, and they substantiate the use of hair Mn levels as a biomarker of environmental Mn exposure in children. PMID:23259818

  7. Mycorrhiza alters the profile of root hairs in trifoliate orange.

    PubMed

    Wu, Qiang-Sheng; Liu, Chun-Yan; Zhang, De-Jian; Zou, Ying-Ning; He, Xin-Hua; Wu, Qing-Hua

    2016-04-01

    Root hairs and arbuscular mycorrhiza (AM) coexist in root systems for nutrient and water absorption, but the relation between AM and root hairs is poorly known. A pot study was performed to evaluate the effects of four different AM fungi (AMF), namely, Claroideoglomus etunicatum, Diversispora versiformis, Funneliformis mosseae, and Rhizophagus intraradices on root hair development in trifoliate orange (Poncirus trifoliata) seedlings grown in sand. Mycorrhizal seedlings showed significantly higher root hair density than non-mycorrhizal seedlings, irrespective of AMF species. AMF inoculation generally significantly decreased root hair length in the first- and second-order lateral roots but increased it in the third- and fourth-order lateral roots. AMF colonization induced diverse responses in root hair diameter of different order lateral roots. Considerably greater concentrations of phosphorus (P), nitric oxide (NO), glucose, sucrose, indole-3-acetic acid (IAA), and methyl jasmonate (MeJA) were found in roots of AM seedlings than in non-AM seedlings. Levels of P, NO, carbohydrates, IAA, and MeJA in roots were correlated with AM formation and root hair development. These results suggest that AMF could alter the profile of root hairs in trifoliate orange through modulation of physiological activities. F. mosseae, which had the greatest positive effects, could represent an efficient AM fungus for increasing fruit yields or decreasing fertilizer inputs in citrus production. PMID:26499883

  8. Functional hair cell mechanotransducer channels are required for aminoglycoside ototoxicity.

    PubMed

    Alharazneh, Abdelrahman; Luk, Lauren; Huth, Markus; Monfared, Ashkan; Steyger, Peter S; Cheng, Alan G; Ricci, Anthony J

    2011-01-01

    Aminoglycosides (AG) are commonly prescribed antibiotics with potent bactericidal activities. One main side effect is permanent sensorineural hearing loss, induced by selective inner ear sensory hair cell death. Much work has focused on AG's initiating cell death processes, however, fewer studies exist defining mechanisms of AG uptake by hair cells. The current study investigated two proposed mechanisms of AG transport in mammalian hair cells: mechanotransducer (MET) channels and endocytosis. To study these two mechanisms, rat cochlear explants were cultured as whole organs in gentamicin-containing media. Two-photon imaging of Texas Red conjugated gentamicin (GTTR) uptake into live hair cells was rapid and selective. Hypocalcemia, which increases the open probability of MET channels, increased AG entry into hair cells. Three blockers of MET channels (curare, quinine, and amiloride) significantly reduced GTTR uptake, whereas the endocytosis inhibitor concanavalin A did not. Dynosore quenched the fluorescence of GTTR and could not be tested. Pharmacologic blockade of MET channels with curare or quinine, but not concanavalin A or dynosore, prevented hair cell loss when challenged with gentamicin for up to 96 hours. Taken together, data indicate that the patency of MET channels mediated AG entry into hair cells and its toxicity. Results suggest that limiting permeation of AGs through MET channel or preventing their entry into endolymph are potential therapeutic targets for preventing hair cell death and hearing loss. PMID:21818312

  9. Lack of Collagen VI Promotes Wound-Induced Hair Growth.

    PubMed

    Chen, Peiwen; Cescon, Matilde; Bonaldo, Paolo

    2015-10-01

    Collagen VI is an extracellular matrix molecule that is abundantly expressed in the skin. However, the role of collagen VI in hair follicle growth is unknown. Here, we show that collagen VI is strongly deposited in hair follicles, and is markedly upregulated by skin wounding. Lack of collagen VI in Col6a1(-/-) mice delays hair cycling and growth under physiological conditions, but promotes wound-induced hair regrowth without affecting skin regeneration. Conversely, addition of purified collagen VI rescues the abnormal wound-induced hair regrowth in Col6a1(-/-) mice. Mechanistic studies revealed that the increased wound-induced hair regrowth of Col6a1(-/-) mice is triggered by activation of the Wnt/β-catenin signaling pathway, and is abolished by inhibition of this pathway. These findings highlight the essential relationships between extracellular matrix (ECM) and hair follicle regeneration, and suggest that collagen VI could be a potential therapeutic target for hair loss and other skin-related diseases. PMID:25989472

  10. Functional Hair Cell Mechanotransducer Channels Are Required for Aminoglycoside Ototoxicity

    PubMed Central

    Huth, Markus; Monfared, Ashkan; Steyger, Peter S.; Cheng, Alan G.; Ricci, Anthony J.

    2011-01-01

    Aminoglycosides (AG) are commonly prescribed antibiotics with potent bactericidal activities. One main side effect is permanent sensorineural hearing loss, induced by selective inner ear sensory hair cell death. Much work has focused on AG's initiating cell death processes, however, fewer studies exist defining mechanisms of AG uptake by hair cells. The current study investigated two proposed mechanisms of AG transport in mammalian hair cells: mechanotransducer (MET) channels and endocytosis. To study these two mechanisms, rat cochlear explants were cultured as whole organs in gentamicin-containing media. Two-photon imaging of Texas Red conjugated gentamicin (GTTR) uptake into live hair cells was rapid and selective. Hypocalcemia, which increases the open probability of MET channels, increased AG entry into hair cells. Three blockers of MET channels (curare, quinine, and amiloride) significantly reduced GTTR uptake, whereas the endocytosis inhibitor concanavalin A did not. Dynosore quenched the fluorescence of GTTR and could not be tested. Pharmacologic blockade of MET channels with curare or quinine, but not concanavalin A or dynosore, prevented hair cell loss when challenged with gentamicin for up to 96 hours. Taken together, data indicate that the patency of MET channels mediated AG entry into hair cells and its toxicity. Results suggest that limiting permeation of AGs through MET channel or preventing their entry into endolymph are potential therapeutic targets for preventing hair cell death and hearing loss. PMID:21818312

  11. Female pattern hair loss.

    PubMed

    Singal, Archana; Sonthalia, Sidharth; Verma, Prashant

    2013-01-01

    Female pattern hair loss (FPHL) is a common cause of hair loss in women characterized by diffuse reduction in hair density over the crown and frontal scalp with retention of the frontal hairline. Its prevalence increases with advancing age and is associated with significant psychological morbidity. The pathophysiology of FPHL is still not completely understood and seems to be multifactorial. Although androgens have been implicated, the involvement of androgen-independent mechanisms is evident from frequent lack of clinical or biochemical markers of hyperandrogenism in affected women. The role of genetic polymorphisms involving the androgen and estrogen receptors is being increasingly recognized in its causation and predicting treatment response to anti-androgens. There are different clinical patterns and classifications of FPHL, knowledge of which facilitates patient management and research. Chronic telogen effluvium remains as the most important differential diagnosis. Thorough history, clinical examination, and evaluation are essential to confirm diagnosis. Patients with clinical signs of androgen excess require assessment of biochemical parameters and imaging studies. It is prudent to screen the patients for metabolic syndrome and cardiovascular risk factors. The treatment comprises medical and/or surgical modalities. Medical treatment should be initiated early as it effectively arrests hair loss progression rather than stimulating regrowth. Minoxidil continues to be the first line therapy whereas anti-androgens form the second line of treatment. The progressive nature of FPHL mandates long-term treatment for sustained effect. Medical therapy may be supplemented with cosmetic concealment in those desirous of greater hair density. Surgery may be worthwhile in some carefully selected patients. PMID:23974580

  12. Isolation and characterization of an outer membrane protein of Salmonella paratyphi B: a mitogen and polyclonal activator of human B lymphocytes.

    PubMed Central

    Sager, S; Virella, G; Chen, W Y; Fudenberg, H H

    1984-01-01

    Salmonella paratyphi B (S. paratyphi B) has been previously characterized as a human T-independent polyclonal B cell activator. To define further the nature of the bacterial structure responsible for these properties, we studied the effects of autoclaving and enzyme treatment of S. paratyphi B on its stimulatory capacity. We found that both autoclaving and papain treatment decreased the ability of S. paratyphi B to induce B cell activation, while trypsin treatment did not affect this capacity. Neither type of treatment affected the binding of S. paratyphi B to lymphocytes, suggesting that binding and B cell stimulation are mediated by different structures. The observation that B cell stimulation was significantly reduced by papain treatment led us to attempt to purify membrane proteins so that we could investigate whether they shared the stimulating capacity of S. paratyphi B. A water-insoluble, 43-45,000 mol. wt. protein, rich in aspartic acid, glutamine, glycine, alanine and leucine, similar in mol. wt. and physicochemical chemical properties to the porins of other gram negative bacteria, was isolated and designated as outer membrane protein (OMP). This protein was equally efficient to S. paratyphi B in inducing T-independent B cell activation. By performing time-course studies of [3H]-thymidine incorporation we observed a burst of mitogenic activity after stimulation of PBL or purified B cells with both S. paratyphi B and OMP peaking at 48-96 hr of culture (compared to 96-120 hr for the PWM proliferation peak), and with a magnitude of roughly 10% of that observed after PWM stimulation. Given the fact that the proportion of B lymphocytes in PBL is 4-12%, it appears likely that the proliferation burst seen with S. paratyphi B and OMP corresponds to a mitogenic effect mainly restricted to the B cell population. Images Figure 1 PMID:6370841

  13. Nutritional factors and hair loss.

    PubMed

    Rushton, D H

    2002-07-01

    The literature reveals what little is known about nutritional factors and hair loss. What we do know emanates from studies in protein-energy malnutrition, starvation, and eating disorders. In otherwise healthy individuals, nutritional factors appear to play a role in subjects with persistent increased hair shedding. Hård, 40 years ago, demonstrated the importance of iron supplements in nonanaemic, iron-deficient women with hair loss. Serum ferritin concentrations provide a good assessment of an individual's iron status. Rushton et al. first published data showing that serum ferritin concentrations were a factor in female hair loss and, 10 years later, Kantor et al. confirmed this association. What level of serum ferritin to employ in subjects with increased hair shedding is yet to be definitively established but 70 micro g/L, with a normal erythrocyte sedimentation rate (< 10 mm/h), is recommended. The role of the essential amino acid, l-lysine in hair loss also appears to be important. Double-blind data confirmed the findings of an open study in women with increased hair shedding, where a significant proportion responded to l-lysine and iron therapy. There is no evidence to support the popular view that low serum zinc concentrations cause hair loss. Excessive intakes of nutritional supplements may actually cause hair loss and are not recommended in the absence of a proven deficiency. While nutritional factors affect the hair directly, one should not forget that they also affect the skin. In the management of subjects with hair loss, eliminating scaling problems is important as is good hair care advice and the need to explain fully the hair cycle. Many individuals reduced their shampooing frequency due to fear of losing more hair but this increases the amount seen in subsequent shampoos fuelling their fear of going bald and adversely affecting their quality of life. PMID:12190640

  14. Inner ear hair cells deteriorate in mice engineered to have no or diminished innervation

    PubMed Central

    Kersigo, Jennifer; Fritzsch, Bernd

    2015-01-01

    The innervation of the inner ear critically depends on the two neurotrophins Ntf3 and Bdnf. In contrast to this molecularly well-established dependency, evidence regarding the need of innervation for long-term maintenance of inner ear hair cells is inconclusive, due to experimental variability. Mutant mice that lack both neurotrophins could shed light on the long-term consequences of innervation loss on hair cells without introducing experimental variability, but do not survive after birth. Mutant mice with conditional deletion of both neurotrophins lose almost all innervation by postnatal day 10 and show an initially normal development of hair cells by this stage. No innervation remains after 3 weeks and complete loss of all innervation results in near complete loss of outer and many inner hair cells of the organ of Corti within 4 months. Mutants that retain one allele of either neurotrophin have only partial loss of innervation of the organ of Corti and show a longer viability of cochlear hair cells with more profound loss of inner hair cells. By 10 months, hair cells disappear with a base to apex progression, proportional to the residual density of innervation and similar to carboplatin ototoxicity. Similar to reports of hair cell loss after aminoglycoside treatment, blobbing of stereocilia of apparently dying hair cells protrude into the cochlear duct. Denervation of vestibular sensory epithelia for several months also resulted in variable results, ranging from unusual hair cells resembling the aberrations found in the organ of Corti, to near normal hair cells in the canal cristae. Fusion and/or resorption of stereocilia and loss of hair cells follows a pattern reminiscent of Myo6 and Cdc42 null mice. Our data support a role of innervation for long-term maintenance but with a remarkable local variation that needs to be taken into account when attempting regeneration of the organ of Corti. PMID:25852547

  15. Dkk4 and Eda Regulate Distinctive Developmental Mechanisms for Subtypes of Mouse Hair

    PubMed Central

    Cui, Chang-Yi; Kunisada, Makoto; Piao, Yulan; Childress, Victoria; Ko, Minoru S. H.; Schlessinger, David

    2010-01-01

    The mouse hair coat comprises protective “primary” and thermo-regulatory “secondary” hairs. Primary hair formation is ectodysplasin (Eda) dependent, but it has been puzzling that Tabby (Eda-/y) mice still make secondary hair. We report that Dickkopf 4 (Dkk4), a Wnt antagonist, affects an auxiliary pathway for Eda-independent development of secondary hair. A Dkk4 transgene in wild-type mice had no effect on primary hair, but secondary hairs were severely malformed. Dkk4 action on secondary hair was further demonstrated when the transgene was introduced into Tabby mice: the usual secondary follicle induction was completely blocked. The Dkk4-regulated secondary hair pathway, like the Eda-dependent primary hair pathway, is further mediated by selective activation of Shh. The results thus reveal two complex molecular pathways that distinctly regulate subtype-based morphogenesis of hair follicles, and provide a resolution for the longstanding puzzle of hair formation in Tabby mice lacking Eda. PMID:20386733

  16. Cochlear hair cells: The sound-sensing machines.

    PubMed

    Goutman, Juan D; Elgoyhen, A Belén; Gómez-Casati, María Eugenia

    2015-11-14

    The sensory epithelium of the mammalian inner ear contains two types of mechanosensory cells: inner (IHC) and outer hair cells (OHC). They both transduce mechanical force generated by sound waves into electrical signals. In their apical end, these cells possess a set of stereocilia representing the mechanosensing organelles. IHC are responsible for detecting sounds and transmitting the acoustic information to the brain by converting graded depolarization into trains of action potentials in auditory nerve fibers. OHC are responsible for the active mechanical amplification process that leads to the fine tuning and high sensitivity of the mammalian inner ear. This active amplification is the consequence of the ability of OHC to alter their cell length in response to changes in membrane potential, and is controlled by an efferent inhibitory innervation. Medial olivocochlear efferent fibers, originating in the brainstem, synapse directly at the base of OHC and release acetylcholine. A very special type of nicotinic receptor, assembled by α9α10 subunits, participates in this synapse. Here we review recent knowledge and the role of both afferent and efferent synapse in the inner ear. PMID:26335749

  17. Activation of Immune and Defense Responses in the Intestinal Mucosa by Outer Membrane Vesicles of Commensal and Probiotic Escherichia coli Strains

    PubMed Central

    José Fábrega, María; Aguilera, Laura; Giménez, Rosa; Varela, Encarna; Alexandra Cañas, María; Antolín, María; Badía, Josefa

    2016-01-01

    The influence of microbiota in human health is well-known. Imbalances in microbiome structure have been linked to several diseases. Modulation of microbiota composition through probiotic therapy is an attempt to harness the beneficial effects of commensal microbiota. Although, there is wide knowledge of the responses induced by gut microbiota, the microbial factors that mediate these effects are not well-known. Gram-negative bacteria release outer membrane vesicles (OMVs) as a secretion mechanism of microbial factors, which have an important role in intercellular communication. Here, we investigated whether OMVs from the probiotic Escherichia coli strain Nissle 1917 (EcN) or the commensal E. coli strain ECOR12 trigger immune responses in various cellular models: (i) peripheral blood mononuclear cells (PBMCs) as a model of intestinal barrier disruption, (ii) apical stimulation of Caco-2/PMBCs co-culture as a model of intact intestinal mucosa, and (iii) colonic mucosa explants as an ex vivo model. Stimulations with bacterial lysates were also performed. Whereas, both OMVs and lysates activated expression and secretion of several cytokines and chemokines in PBMCs, only OMVs induced basolateral secretion and mRNA upregulation of these mediators in the co-culture model. We provide evidence that OMVs are internalized in polarized Caco-2 cells. The activated epithelial cells elicit a response in the underlying immunocompetent cells. The OMVs effects were corroborated in the ex vivo model. This experimental study shows that OMVs are an effective strategy used by beneficial gut bacteria to communicate with and modulate host responses, activating signaling events through the intestinal epithelial barrier. PMID:27242727

  18. Activation of Immune and Defense Responses in the Intestinal Mucosa by Outer Membrane Vesicles of Commensal and Probiotic Escherichia coli Strains.

    PubMed

    José Fábrega, María; Aguilera, Laura; Giménez, Rosa; Varela, Encarna; Alexandra Cañas, María; Antolín, María; Badía, Josefa; Baldomà, Laura

    2016-01-01

    The influence of microbiota in human health is well-known. Imbalances in microbiome structure have been linked to several diseases. Modulation of microbiota composition through probiotic therapy is an attempt to harness the beneficial effects of commensal microbiota. Although, there is wide knowledge of the responses induced by gut microbiota, the microbial factors that mediate these effects are not well-known. Gram-negative bacteria release outer membrane vesicles (OMVs) as a secretion mechanism of microbial factors, which have an important role in intercellular communication. Here, we investigated whether OMVs from the probiotic Escherichia coli strain Nissle 1917 (EcN) or the commensal E. coli strain ECOR12 trigger immune responses in various cellular models: (i) peripheral blood mononuclear cells (PBMCs) as a model of intestinal barrier disruption, (ii) apical stimulation of Caco-2/PMBCs co-culture as a model of intact intestinal mucosa, and (iii) colonic mucosa explants as an ex vivo model. Stimulations with bacterial lysates were also performed. Whereas, both OMVs and lysates activated expression and secretion of several cytokines and chemokines in PBMCs, only OMVs induced basolateral secretion and mRNA upregulation of these mediators in the co-culture model. We provide evidence that OMVs are internalized in polarized Caco-2 cells. The activated epithelial cells elicit a response in the underlying immunocompetent cells. The OMVs effects were corroborated in the ex vivo model. This experimental study shows that OMVs are an effective strategy used by beneficial gut bacteria to communicate with and modulate host responses, activating signaling events through the intestinal epithelial barrier. PMID:27242727

  19. Postnatal Refinement of Auditory Hair Cell Planar Polarity Deficits Occurs in the Absence of Vangl2

    PubMed Central

    Copley, Catherine O.; Duncan, Jeremy S.; Liu, Chang; Cheng, Haixia

    2013-01-01

    The distinctive planar polarity of auditory hair cells is evident in the polarized organization of the stereociliary bundle. Mutations in the core planar cell polarity gene Van Gogh-like 2 (Vangl2) result in hair cells that fail to properly orient their stereociliary bundles along the mediolateral axis of the cochlea. The severity of this phenotype is graded along the length of the cochlea, similar to the hair cell differentiation gradient, suggesting that an active refinement process corrects planar polarity phenotypes in Vangl2 knock-out (KO) mice. Because Vangl2 gene deletions are lethal, Vangl2 conditional knock-outs (CKOs) were generated to test this hypothesis. When crossed with Pax2–Cre, Vangl2 is deleted from the inner ear, yielding planar polarity phenotypes similar to Vangl2 KOs at late embryonic stages except that Vangl2 CKO mice are viable and do not have craniorachischisis like Vangl2 KOs. Quantification of planar polarity deficits through postnatal development demonstrates the activity of a Vangl2-independent refinement process that rescues the planar polarity phenotype within 10 d of birth. In contrast, the Pax2–Cre;Vangl2 CKO has profound changes in the shape and distribution of outer pillar cell and Deiters' cell phalangeal processes that are not corrected during the period of planar polarity refinement. Auditory brainstem response analyses of adult mice show a 10–15 dB shift in auditory threshold, and distortion product otoacoustic emission measurements indicate that this mild hearing deficit is of cochlear origin. Together, these data demonstrate a Vangl2-independent refinement mechanism that actively reorients auditory stereociliary bundles and reveals an unexpected role of Vangl2 during supporting cell morphogenesis. PMID:23986237

  20. Protection of immunocompromised mice against lethal infection with Pseudomonas aeruginosa by active or passive immunization with recombinant P. aeruginosa outer membrane protein F and outer membrane protein I fusion proteins.

    PubMed Central

    von Specht, B U; Knapp, B; Muth, G; Bröker, M; Hungerer, K D; Diehl, K D; Massarrat, K; Seemann, A; Domdey, H

    1995-01-01

    Recombinant outer membrane proteins (Oprs) of Pseudomonas aeruginosa were expressed in Escherichia coli as glutathione S-transferase (GST)-linked fusion proteins. GST-linked Oprs F and I (GST-OprF190-350 [GST linked to OprF spanning amino acids 190 to 350] and GST-OprI21-83, respectively) and recombinant hybrid Oprs (GST-OprF190-342-OprI21-83 and GST-OprI21-83-OprF190-350) were isolated and tested for their efficacy as vaccines in immunodeficient mice. GST-OprF-OprI protected the mice against a 975-fold 50% lethal dose of P. aeruginosa. Expression of GST-unfused OprF-OprI failed in E. coli, although this hybrid protein has been expressed without a fusion part in Saccharomyces cerevisiae and used for immunizing rabbits. The immune rabbit sera protected severe combined deficient (SCID) mice against a 1,000-fold 50% lethal dose of P. aeruginosa. Evidence is provided to show that the most C-terminal part of OprF (i.e., amino acids 332 to 350) carries an important protective epitope. Opr-based hybrid proteins may have implications for a clinical vaccine against P. aeruginosa. PMID:7729895

  1. 28 CFR 551.4 - Hair length.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Hair length. 551.4 Section 551.4 Judicial... Hair length. (a) The Warden may not restrict hair length if the inmate keeps it neat and clean. (b) The Warden shall require an inmate with long hair to wear a cap or hair net when working in food service...

  2. 28 CFR 551.4 - Hair length.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Hair length. 551.4 Section 551.4 Judicial... Hair length. (a) The Warden may not restrict hair length if the inmate keeps it neat and clean. (b) The Warden shall require an inmate with long hair to wear a cap or hair net when working in food service...

  3. 28 CFR 551.4 - Hair length.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Hair length. 551.4 Section 551.4 Judicial... Hair length. (a) The Warden may not restrict hair length if the inmate keeps it neat and clean. (b) The Warden shall require an inmate with long hair to wear a cap or hair net when working in food service...

  4. 28 CFR 551.4 - Hair length.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Hair length. 551.4 Section 551.4 Judicial... Hair length. (a) The Warden may not restrict hair length if the inmate keeps it neat and clean. (b) The Warden shall require an inmate with long hair to wear a cap or hair net when working in food service...

  5. 28 CFR 551.4 - Hair length.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Hair length. 551.4 Section 551.4 Judicial... Hair length. (a) The Warden may not restrict hair length if the inmate keeps it neat and clean. (b) The Warden shall require an inmate with long hair to wear a cap or hair net when working in food service...

  6. Outer Planet Flagship Mission

    NASA Astrophysics Data System (ADS)

    Cutts, James; Niebur, C.; Dudzinski, L.; Coradini, M.; Lebreton, J.

    2008-09-01

    Studies for Outer Planet Missions have been ongoing for many years, but in 2007 NASA commissioned four specific studies to be considered for further examination; the Europa Explorer, Titan Explorer, Enceladus Mission and Jupiter Science Orbiter. During the same time frame ESA invited Outer Planet proposals under the Cosmic Vision call. Two were submitted, TandEm and LaPlace, which focused on Titan/Enceladus and Jupiter System science respectively. In 2008, NASA selected two of the missions, Europa Explorer and Titan Explorer, and ESA selected the two outer planet proposals for further study. This poster describes the process by which NASA and ESA are collaborating on the current studies which are now named the Titan/Saturn (TSSM) and Europa/Jupiter Missions (EJSM). We provide an update on the background, organization and schedule for these two mission studies.

  7. Outer Planet Flagship Missions

    NASA Astrophysics Data System (ADS)

    Niebur, C.; Dudzinski, L.; Coradini, M.; Lebreton, J.; Cutts, J. A.

    2008-05-01

    Studies for Outer Planet Missions have been ongoing for many years, but in 2007 NASA commissioned four specific studies to be considered for further examination; the Europa Explorer, Titan Explorer, Enceladus Mission and Jupiter Science Orbiter. During the same time frame ESA invited Outer Planet proposals under the Cosmic Vision call. Two were submitted, TandEM and LaPlace, which focused on Titan/Enceladus and Jupiter System science respectively. In 2008, NASA selected two of the missions, Europa Explorer and Titan Explorer, and ESA selected the two outer planet proposals for further study. This poster describes the process by which NASA and ESA are collaborating on the current studies which are now named the Titan/Saturn and Europa/Jupiter Missions. We provide the background, organization and schedule that are presently envisaged for these two mission studies.

  8. Outer Planets Flagship Mission

    NASA Astrophysics Data System (ADS)

    Niebur, C.; Dudzinski, L.; Coradini, M.; Lebreton, J. P.; Cutts, J. A.

    2008-09-01

    Studies for Outer Planet Missions have been ongoing for many years, but in 2007 NASA commissioned four specific studies to be considered for further examination; the Europa Explorer, Titan Explorer, Enceladus Mission and Jupiter Science Orbiter. During the same time frame ESA invited Outer Planet proposals under the Cosmic Vision call. Two were submitted, TandEm and LaPlace, which focused on Titan/Enceladus and Jupiter System science respectively. In 2008, NASA selected two of the missions, Europa Explorer and Titan Explorer, and ESA selected the two outer planet proposals for further study. This poster describes the process by which NASA and ESA are collaborating on the current studies which are now named the Titan/Saturn (TSSM) and Europa/Jupiter Missions (EJSM). We provide an update on the background, organization and schedule for these two mission studies.

  9. Saturn's outer magnetosphere

    NASA Technical Reports Server (NTRS)

    Schardt, A. W.; Behannon, K. W.; Carbary, J. F.; Eviatar, A.; Lepping, R. P.; Siscoe, G. L.

    1983-01-01

    Similarities between the Saturnian and terrestrial outer magnetosphere are examined. Saturn, like Earth, has a fully developed magnetic tail, 80 to 100 RS in diameter. One major difference between the two outer magnetospheres is the hydrogen and nitrogen torus produced by Titan. This plasma is, in general, convected in the corotation direction at nearly the rigid corotation speed. Energies of magnetospheric particles extend to above 500 keV. In contrast, interplanetary protons and ions above 2 MeV have free access to the outer magnetosphere to distances well below the Stormer cutoff. This access presumably occurs through the magnetotail. In addition to the H+, H2+, and H3+ ions primarily of local origin, energetic He, C, N, and O ions are found with solar composition. Their flux can be substantially enhanced over that of interplanetary ions at energies of 0.2 to 0.4 MeV/nuc.

  10. Outer membrane protein purification.

    PubMed

    Arigita, C; Jiskoot, W; Graaf, M R; Kersten, G F

    2001-01-01

    The major outer membrane proteins (OMPs) from Neisseria meningitidis, which are expressed at high levels, are subdivided in five classes based on molecular weight (1,2) (see Table 1). Table 1 Major Meningococcal Outer-Membrane Proteins Outer-membrane proteins Name Molecular maass Function/characteristics Class 1 PorA 44-47 kDa Porin Class 2/3 PorB 37-42 kDa Porin Class 4 Rmp Reductionmodifiableprotein, unknown Class 5 Opa 26-30 kDa Adhesion,opacity protein Opc 25 kDa Invasion, opacity protein Iron-regulated proteins Mirp 37 kDa Iron acquisition (?);majoriron-regulatedprotein FrpB 70 kDa Ferric enterobactin receptor (also FetA) Adapted from ref. (1). PMID:21336748

  11. Organic components in hair-ice

    NASA Astrophysics Data System (ADS)

    Hofmann, Diana; Steffen, Bernhard; Disko, Ulrich; Wagner, Gerhard; Mätzler, Christian

    2013-04-01

    Hair-ice is a rather unknown phenomenon. In contrast to generally known frost needles, originating from atmospheric water and expanding e.g. from plant surfaces in all directions, hair ice grows from the basis of wet, rotten hardwood. The hair-like, flexible, linear structures may reach up to 10 cm in length without any ramifications. Hair-ice appears to be related to the biological activity of a fungus mycelium within the wood. Hair-ice can attract winter-active Collemboles (snow flea, Isotoma nivalis). At the onset of hair-ice melt a very thin fibre becomes apparent, which carries brownish pearl-like water drops. Therefore, it is supposed that organic substances are inherent, which could possibly act as freezing catalyst as well as recrystallization inhibitor. The aim of this work was the chemical characterization of organic substances contained in hair-ice. First analyses of melted hair-ice show a total organic carbon (TOC) value of 235 mg/l in contrast to 11 mg/l total nitrogen. Most of inherent nitrogen (70 %) exists thereby as ammonium. Screened by different (mass spectrometric) methods, no evidence could be found for the initially expected organic substances like proteins, lipids, small volatile substances or carboxylic acids. By coupling of Ultra Performance Liquid Chromatography with a triple quadrupol mass spectrometer (UPLC-MS) a non-resolved chromatogram from a melted hair-ice sample was received. Averaged spectra from different regions are similar among themselves with a broad peak spreading over the mass range 100-650 Da with favored intense, odd-numbered peaks. Such spectra are similar to dissolved organic matter (DOM), known e.g. from terrestrial and marine waters, soil extracts or aerosols. In the next step, samples were desalted and concentrated by solid phase extraction (SPE) and subsequently analyzed by flow injection analysis (FIA) in a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FTICR-MS), equipped with an ESI source and a 7 T

  12. Flux control exerted by mitochondrial outer membrane carnitine palmitoyltransferase over beta-oxidation, ketogenesis and tricarboxylic acid cycle activity in hepatocytes isolated from rats in different metabolic states.

    PubMed Central

    Drynan, L; Quant, P A; Zammit, V A

    1996-01-01

    The Flux Control Coefficients of mitochondrial outer membrane carnitine palmitoyltransferase (CPT I) with respect to the overall rates of beta-oxidation, ketogenesis and tricarboxylic acid cycle activity were measured in hepatocytes isolated from rats in different metabolic states (fed, 24 h-starved, starved-refed and starved/insulin-treated). These conditions were chosen because there is controversy as to whether, when significant control ceases to be exerted by CPT I over the rate of fatty oxidation [Moir and Zammit (1994) Trends Biochem. Sci. 19, 313-317], this is transferred to one or more steps proximal to acylcarnitine synthesis (e.g. decreased delivery of fatty acids to the liver) or to the reaction catalysed by mitochondrial 3-hydroxy-3-methyl-glutaryl-CoA synthase [Hegardt (1995) Biochem. Soc. Trans. 23, 486-490]. Therefore isolated hepatocytes were used in the present study to exclude the involvement of changes in the rate of delivery of non-esterified fatty acids (NEFA) to the liver, such as occur in vivo, and to ascertain whether, under conditions of constant supply of NEFA, CPT I retains control over the relevant fluxes of fatty acid oxidation to ketones and carbon dioxide, or whether control is transferred to another (intrahepatocytic) site. The results clearly show that the Flux Control Coefficients of CPT I with respect to overall beta-oxidation and ketogenesis are very high under all conditions investigated, indicating that control is not lost to another intrahepatic site during the metabolic transitions studied. The control of CPT I over tricarboxylic acid cycle activity was always very low. The significance of these findings for the integration of fatty acid and carbohydrate metabolism in the liver is discussed. PMID:8760364

  13. Shigella flexneri 3a Outer Membrane Protein C Epitope Is Recognized by Human Umbilical Cord Sera and Associated with Protective Activity

    PubMed Central

    Jarząb, Anna; Witkowska, Danuta; Ziomek, Edmund; Dąbrowska, Anna; Szewczuk, Zbigniew; Gamian, Andrzej

    2013-01-01

    Shigella flexneri 3a is one of the five major strains of the Shigella genus responsible for dysentery, especially among children, in regions of high poverty and poor sanitation. The outer membrane proteins (OMP) of this bacterium elicit immunological responses and are considered a prime target for vaccine development. When injected into mice they elicit a protective immunological response against a lethal dose of the pathogen. The OMPs from S. flexneri 3a were isolated and resolved by two-dimension-SDS-PAGE. Two 38-kDa spots were of particular interest since in our earlier studies OMPs of such molecular mass were found to interact with umbilical cord sera. These two spots were identified as OmpC by ESI-MS/MS spectrometry. By DNA sequencing, the ompC gene from S. flexneri 3a was identical to ompC from S. flexneri 2a [Gene Bank: 24113600]. A 3D model of OmpC was built and used to predict B-cell type (discontinuous) antigenic epitopes. Six epitopes bearing the highest score were selected and the corresponding peptides were synthesized. Only the peptides representing loop V of OmpC reacted strongly with the umbilical cord serum immunoglobulins. To determine which amino acids are essential for the antigenic activity of the epitope, the loop V was scanned with a series of dodecapeptides. The peptide RYDERY was identified as a minimal sequence for the loop V epitope. Truncation at either the C- or N-terminus rendered this peptide inactive. Apart from C-terminal tyrosine, substitution of each of the remaining five amino acids with glycine, led to a precipitous loss of immunological activity. This peptide may serve as a ligand in affinity chromatography of OmpC-specific antibodies and as a component of a vaccine designed to boost human immune defenses against enterobacterial infections. PMID:23940590

  14. Calculated activity of Mn2+ at the outer surface of the root cell plasma membrane governs Mn nutrition of cowpea seedlings.

    PubMed

    Kopittke, Peter M; Blamey, F Pax C; Wang, Peng; Menzies, Neal W

    2011-07-01

    Manganese (Mn) is an essential micronutrient for plant growth but is often toxic in acid or waterlogged soils. Using cowpea (Vigna unguiculata L. Walp.) grown with 0.05-1500 μM Mn in solution, two short-term (48 h) solution culture experiments examined if the effects of cations (Ca, Mg, Na, Al, or H) on Mn nutrition are related to the root cells' plasma membrane (PM) surface potential, ψ(0)(0). When grown in solutions containing levels of Mn that were toxic, both relative root elongation rate (RRER) and root tissue Mn concentration were more closely related to the activity of Mn(2+) at the outer surface of the PM, {Mn(2+)}(0)(0) (R(2)=0.812 and 0.871) than to its activity in the bulk solution, {Mn(2+)}(b) (R(2)=0.673 and 0.769). This was also evident at lower levels of Mn (0.05-10 μM) relevant to studies investigating Mn as an essential micronutrient (R(2)=0.791 versus 0.590). In addition, changes in the electrical driving force for ion transport across the PM influenced both RRER and the Mn concentration in roots. The {Mn(2+)}(b) causing a 50% reduction in root growth was found to be c. 500 to >1000 μM (depending upon solution composition), whilst the corresponding value was 3300 μM when related to {Mn(2+)}(0)(0). Although specific effects such as competition are not precluded, the data emphasize the importance of non-specific electrostatic effects in the Mn nutrition of cowpea seedlings over a 1×10(5)-fold range of Mn concentration in solution. PMID:21511910

  15. Shigella flexneri 3a outer membrane protein C epitope is recognized by human umbilical cord sera and associated with protective activity.

    PubMed

    Jarząb, Anna; Witkowska, Danuta; Ziomek, Edmund; Dąbrowska, Anna; Szewczuk, Zbigniew; Gamian, Andrzej

    2013-01-01

    Shigella flexneri 3a is one of the five major strains of the Shigella genus responsible for dysentery, especially among children, in regions of high poverty and poor sanitation. The outer membrane proteins (OMP) of this bacterium elicit immunological responses and are considered a prime target for vaccine development. When injected into mice they elicit a protective immunological response against a lethal dose of the pathogen. The OMPs from S. flexneri 3a were isolated and resolved by two-dimension-SDS-PAGE. Two 38-kDa spots were of particular interest since in our earlier studies OMPs of such molecular mass were found to interact with umbilical cord sera. These two spots were identified as OmpC by ESI-MS/MS spectrometry. By DNA sequencing, the ompC gene from S. flexneri 3a was identical to ompC from S. flexneri 2a [Gene Bank: 24113600]. A 3D model of OmpC was built and used to predict B-cell type (discontinuous) antigenic epitopes. Six epitopes bearing the highest score were selected and the corresponding peptides were synthesized. Only the peptides representing loop V of OmpC reacted strongly with the umbilical cord serum immunoglobulins. To determine which amino acids are essential for the antigenic activity of the epitope, the loop V was scanned with a series of dodecapeptides. The peptide RYDERY was identified as a minimal sequence for the loop V epitope. Truncation at either the C- or N-terminus rendered this peptide inactive. Apart from C-terminal tyrosine, substitution of each of the remaining five amino acids with glycine, led to a precipitous loss of immunological activity. This peptide may serve as a ligand in affinity chromatography of OmpC-specific antibodies and as a component of a vaccine designed to boost human immune defenses against enterobacterial infections. PMID:23940590

  16. Access to novel fluorovinylidene ligands via exploitation of outer-sphere electrophilic fluorination: new insights into C-F bond formation and activation.

    PubMed

    Milner, Lucy M; Hall, Lewis M; Pridmore, Natalie E; Skeats, Matthew K; Whitwood, Adrian C; Lynam, Jason M; Slattery, John M

    2016-01-28

    Metal vinylidene complexes are widely encountered, or postulated, as intermediates in a range of important metal-mediated transformations of alkynes. However, fluorovinylidene complexes have rarely been described and their reactivity is largely unexplored. By making use of the novel outer-sphere electrophilic fluorination (OSEF) strategy we have developed a rapid, robust and convenient method for the preparation of fluorovinylidene and trifluoromethylvinylidene ruthenium complexes from non-fluorinated alkynes. Spectroscopic investigations (NMR and UV/Vis), coupled with TD-DFT studies, show that fluorine incorporation results in significant changes to the electronic structure of the vinylidene ligand. The reactivity of fluorovinylidene complexes shows many similarities to non-fluorinated analogues, but also some interesting differences, including a propensity to undergo unexpected C-F bond cleavage reactions. Heating fluorovinylidene complex [Ru(η(5)-C5H5)(PPh3)2(C[double bond, length as m-dash]C{F}R)][BF4] led to C-H activation of a PPh3 ligand to form an orthometallated fluorovinylphosphonium ligand. Reaction with pyridine led to nucleophilic attack at the metal-bound carbon atom of the vinylidene to form a vinyl pyridinium species, which undergoes both C-H and C-F activation to give a novel pyridylidene complex. Addition of water, in the presence of chloride, leads to anti-Markovnikov hydration of a fluorovinylidene complex to form an α-fluoroaldehyde, which slowly rearranges to its acyl fluoride isomer. Therefore, fluorovinylidenes ligands may be viewed as synthetic equivalents of 1-fluoroalkynes providing access to reactivity not possible by other routes. PMID:26701305

  17. Mechanistic Studies on the Use of Polygonum multiflorum for the Treatment of Hair Graying.

    PubMed

    Han, Ming-Nuan; Lu, Jian-Mei; Zhang, Guang-Yuan; Yu, Jie; Zhao, Rong-Hua

    2015-01-01

    Polygonum multiflorum is a traditional Chinese medicine with a long history in hair growth promotion and hair blackening. The purpose of the study was to examine the effect and the mechanism of Polygonum multiflorum in hair blackening. C57BL/6 mice hair fade was induced with H2O2 and used in this research. Hair pigmentogenesis promotion activities of Polygonum Multiflorum Radix (PMR, raw crude drug), Polygonum Multiflorum Radix Preparata (PMRP, processed crude drug), and their major chemical constituent TSG were investigated. The regulation effects of several cytokines and enzymes such as POMC, α-MSH, MC1R, ASIP, MITF, TYR, TRP-1, and TRP-2 were investigated. PMR group gave out the most outstanding black hair among all groups with the highest contents of total melanin, α-MSH, MC1R, and TYR. Promotion of hair pigmentogenesis was slightly decreased after processing in the PMRP group. TSG as the major constituent of PMR showed weaker hair color regulation effects than both PMR and PMRP. PMR, but not PMRP, should be used to blacken hair. The α-MSH, MC1R, and TYR were the major targets in the medicinal use of PMR in hair graying. Chemical constituents other than TSG may contribute to the hair color regulation activity of PMR. PMID:26640791

  18. Mechanistic Studies on the Use of Polygonum multiflorum for the Treatment of Hair Graying

    PubMed Central

    Han, Ming-Nuan; Lu, Jian-Mei; Zhang, Guang-Yuan; Yu, Jie; Zhao, Rong-Hua

    2015-01-01

    Polygonum multiflorum is a traditional Chinese medicine with a long history in hair growth promotion and hair blackening. The purpose of the study was to examine the effect and the mechanism of Polygonum multiflorum in hair blackening. C57BL/6 mice hair fade was induced with H2O2 and used in this research. Hair pigmentogenesis promotion activities of Polygonum Multiflorum Radix (PMR, raw crude drug), Polygonum Multiflorum Radix Preparata (PMRP, processed crude drug), and their major chemical constituent TSG were investigated. The regulation effects of several cytokines and enzymes such as POMC, α-MSH, MC1R, ASIP, MITF, TYR, TRP-1, and TRP-2 were investigated. PMR group gave out the most outstanding black hair among all groups with the highest contents of total melanin, α-MSH, MC1R, and TYR. Promotion of hair pigmentogenesis was slightly decreased after processing in the PMRP group. TSG as the major constituent of PMR showed weaker hair color regulation effects than both PMR and PMRP. PMR, but not PMRP, should be used to blacken hair. The α-MSH, MC1R, and TYR were the major targets in the medicinal use of PMR in hair graying. Chemical constituents other than TSG may contribute to the hair color regulation activity of PMR. PMID:26640791

  19. Hair Styling Appliances

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Key tool of Redken Laboratories new line of hair styling appliances is an instrument called a thermograph, a heat sensing device originally developed by Hughes Aircraft Co. under U.S. Army and NASA funding. Redken Laboratories bought one of the early models of the Hughes Probeye Thermal Video System or TVS which detects the various degrees of heat emitted by an object and displays the results in color on a TV monitor with colors representing different temperatures detected.

  20. Normal and aging hair biology and structure 'aging and hair'.

    PubMed

    Goodier, Molly; Hordinsky, Maria

    2015-01-01

    Much like an individual's hairstyle, hair fibers along the scalp see a number of changes over the course of one's lifetime. As the decades pass, the shine and volume synonymous with youthful hair may give way to thin, dull, and brittle hair commonly associated with aging. These changes are a result of a compilation of genetic and environmental elements influencing the cells of the hair follicle, specifically the hair follicle stem cells and melanocytes. Telomere shortening, decrease in cell numbers, and particular transcription factors have all been implicated in this process. In turn, these molecular alterations lead to structural modifications of the hair fiber, decrease in melanin production, and lengthening of the telogen phase of the hair cycle. Despite this inevitable progression with aging, there exists an array of treatments such as light therapy, minoxidil, and finasteride which have been designed to mitigate the effects of aging, particularly balding and thinning hair. Although each works through a different mechanism, all aim to maintain or potentially restore the youthful quality of hair. PMID:26370639

  1. Matriptase Expression and Zymogen Activation in Human Pilosebaceous Unit

    PubMed Central

    Wu, Bai-Yao; Lee, Shiao-Pieng; Hsiao, Hui-Chung; Chiu, Han; Chen, Chi-Yung; Yeo, Yee Hui; Lee, Herng-Sheng; Chen, Ya-Wen; Kaul, Malvika; Kataoka, Hiroaki; Johnson, Michael D.; Lin, Chen-Yong

    2014-01-01

    Studies of human genetic disorders and mouse models reveal the important roles of matriptase in hair growth. Here, we investigate matriptase expression and zymogen activation in hair follicles. We show: 1) layer-dependent distribution patterns, with much higher matriptase expression in cells of the outer root sheath and matrix cells of the hair bulb than in cells of the inner root sheath; 2) cycle-dependent expression patterns, with matriptase expressed in the anagen and catagen phases of the hair lifecycle, but not in the telogen phase; 3) reduced expression of the matriptase inhibitor, HAI-1, in the catagen phase, suggesting increased proteolytic activity in this phase; and 4) definitive matriptase zymogen activation patterns, with the highest matriptase activation observed in matrix cells and outer root sheath cells in the isthmus/bulge region. In sebaceous glands, matriptase is highly expressed in basal and ductal cells, with much lower expression in the differentiated, lipid-filled cells of the interior. We also show that matriptase potently activates hepatocyte growth factor (HGF) in vitro, and that the HGF receptor, c-Met, is co-expressed in those cells that express activated matriptase. Our observations suggest that the matriptase-HGF-c-MET pathway has the potential to be engaged, primarily in proliferative cells rather than terminally differentiated epithelial cells of the human pilosebaceous unit. PMID:24004857

  2. Female Pattern Hair Loss

    PubMed Central

    Herskovitz, Ingrid; Tosti, Antonella

    2013-01-01

    Context: Female pattern hair loss (FPHL) also known as female androgenetic alopecia is a common condition afflicting millions of women that can be cosmetically disrupting. Prompt diagnosis and treatment are essential for obtaining optimal outcome. This review addresses the clinical presentation of female pattern hair loss, its differential diagnosis and treatment modalities. Evidence Acquisition: A) Diffuse thinning of the crown region with preservation of the frontal hairline (Ludwig’s type) B) The “Christmas tree pattern” where the thinning is wider in the frontal scalp giving the alopecic area a triangular shaped figure resembling a christmas tree. C) Thinning associated with bitemporal recession (Hamilton type). Generally, FPHL is not associated with elevated androgens. Less commonly females with FPHL may have other skin or general signs of hyperandrogenism such as hirsutism, acne, irregular menses, infertility, galactorrhea and insulin resistance. The most common endocrinological abnormality associated with FPHL is polycystic ovarian syndrome (PCOS). Results: The most important diseases to consider in the differential diagnosis of FPHL include Chronic Telogen Effluvium (CTE), Permanent Alopecia after Chemotherapy (PAC), Alopecia Areata Incognito (AAI) and Frontal Fibrosing Alopecia (FFA). This review describes criteria for distinguishing these conditions from FPHL. Conclusions: The only approved treatment for FPHL, which is 2% topical Minoxidil, should be applied at the dosage of 1ml twice day for a minimum period of 12 months. This review will discuss off-label alternative modalities of treatment including 5-alfa reductase inhibitors, antiandrogens, estrogens, prostaglandin analogs, lasers, light treatments and hair transplantation. PMID:24719635

  3. Age-related Changes in Auditory Nerve – Inner Hair Cell Connections, Hair Cell Numbers, Auditory Brain Stem Response and Gap Detection in UM-HET4 Mice

    PubMed Central

    Altschuler, RA; Dolan, DF; Halsey, K; Kanicki, A; Deng, N; Martin, C; Eberle, J; Kohrman, DC; Miller, RA; Schacht, J

    2015-01-01

    This study compared the timing of appearance of three components of age-related hearing loss that determine the pattern and severity of presbycusis: the functional and structural pathologies of sensory cells and neurons and changes in Gap Detection, the latter as an indicator of auditory temporal processing. Using UM-HET4 mice, genetically heterogeneous mice derived from four inbred strains, we studied the integrity of inner and outer hair cells by position along the cochlear spiral, inner hair cell-auditory nerve connections, spiral ganglion neurons, and determined auditory thresholds, as well as pre-pulse and gap inhibition of the acoustic startle reflex (ASR). Comparisons were made between mice of 5-7, 22-24 and 27-29 months of age. There was individual variability among mice in the onset and extent of age-related auditory pathology. At 22-24 months of age a moderate to large loss of outer hair cells was restricted to the apical third of the cochlea and threshold shifts in auditory brain stem response were minimal. There was also a large and significant loss of inner hair cell – auditory nerve connections and a significant reduction in Gap Detection. The expression of Ntf3 in the cochlea was significantly reduced. At 27-29 months of age there was no further change in the mean number of synaptic connections per inner hair cell or in gap detection, but a moderate to large loss of outer hair cells was found across all cochlear turns as well as significantly increased ABR threshold shifts at 4, 12, 24 and 48 kHz. A statistical analysis of correlations on an individual animal basis revealed that neither the hair cell loss nor the ABR threshold shifts correlated with loss of gap detection or with the loss of connections, consistent with independent pathological mechanisms. PMID:25665752

  4. Age-related changes in auditory nerve-inner hair cell connections, hair cell numbers, auditory brain stem response and gap detection in UM-HET4 mice.

    PubMed

    Altschuler, R A; Dolan, D F; Halsey, K; Kanicki, A; Deng, N; Martin, C; Eberle, J; Kohrman, D C; Miller, R A; Schacht, J

    2015-04-30

    This study compared the timing of appearance of three components of age-related hearing loss that determine the pattern and severity of presbycusis: the functional and structural pathologies of sensory cells and neurons and changes in gap detection (GD), the latter as an indicator of auditory temporal processing. Using UM-HET4 mice, genetically heterogeneous mice derived from four inbred strains, we studied the integrity of inner and outer hair cells by position along the cochlear spiral, inner hair cell-auditory nerve connections, spiral ganglion neurons (SGN), and determined auditory thresholds, as well as pre-pulse and gap inhibition of the acoustic startle reflex (ASR). Comparisons were made between mice of 5-7, 22-24 and 27-29 months of age. There was individual variability among mice in the onset and extent of age-related auditory pathology. At 22-24 months of age a moderate to large loss of outer hair cells was restricted to the apical third of the cochlea and threshold shifts in the auditory brain stem response were minimal. There was also a large and significant loss of inner hair cell-auditory nerve connections and a significant reduction in GD. The expression of Ntf3 in the cochlea was significantly reduced. At 27-29 months of age there was no further change in the mean number of synaptic connections per inner hair cell or in GD, but a moderate to large loss of outer hair cells was found across all cochlear turns as well as significantly increased ABR threshold shifts at 4, 12, 24 and 48 kHz. A statistical analysis of correlations on an individual animal basis revealed that neither the hair cell loss nor the ABR threshold shifts correlated with loss of GD or with the loss of connections, consistent with independent pathological mechanisms. PMID:25665752

  5. Hair removal on dermoscopy images.

    PubMed

    Maglogiannis, Ilias; Delibasis, Kostantinos

    2015-08-01

    Digital Dermoscopy is a tool commonly used by dermatologists for assisting the diagnosis of skin lesions. The presence of hair in such dermoscopic images frequently occludes significant diagnostic information and reduces their value. In this work we propose algorithms that successfully identify and remove hair from the dermoscopic images. The proposed algorithms consist of two parts; the first deals with the identification of hair, while the second part concerns the image restoration using interpolation. For the evaluation of the algorithms we used ground truth images with synthetic hair and compared the results with the commonly used in the literature DullRazor tool. According to the experimental results the proposed hair removal algorithms can be used successfully in the detection and removal of both dark and light colored hair. PMID:26736913

  6. Onset of cholinergic efferent synaptic function in sensory hair cells of the rat cochlea.

    PubMed

    Roux, Isabelle; Wersinger, Eric; McIntosh, J Michael; Fuchs, Paul A; Glowatzki, Elisabeth

    2011-10-19

    In the developing mammalian cochlea, the sensory hair cells receive efferent innervation originating in the superior olivary complex. This input is mediated by α9/α10 nicotinic acetylcholine receptors (nAChRs) and is inhibitory due to the subsequent activation of calcium-dependent SK2 potassium channels. We examined the acquisition of this cholinergic efferent input using whole-cell voltage-clamp recordings from inner hair cells (IHCs) in acutely excised apical turns of the rat cochlea from embryonic day 21 to postnatal day 8 (P8). Responses to 1 mm acetylcholine (ACh) were detected from P0 on in almost every IHC. The ACh-activated current amplitude increased with age and demonstrated the same pharmacology as α9-containing nAChRs. Interestingly, at P0, the ACh response was not coupled to SK2 channels, so that the initial cholinergic response was excitatory and could trigger action potentials in IHCs. Coupling to SK current was detected earliest at P1 in a subset of IHCs and by P3 in every IHC studied. Clustered nAChRs and SK2 channels were found on IHCs from P1 on using Alexa Fluor 488 conjugated α-bungarotoxin and SK2 immunohistochemistry. The number of nAChRs clusters increased with age to 16 per IHC at P8. Cholinergic efferent synaptic currents first appeared in a subset of IHCs at P1 and by P3 in every IHC studied, contemporaneously with ACh-evoked SK currents, suggesting that SK2 channels may be necessary at onset of synaptic function. An analogous pattern of development was observed for the efferent synapses that form later (P6-P8) on outer hair cells in the basal cochlea. PMID:22016543

  7. Through form to function: root hair development and nutrient uptake

    NASA Technical Reports Server (NTRS)

    Gilroy, S.; Jones, D. L.

    2000-01-01

    Root hairs project from the surface of the root to aid nutrient and water uptake and to anchor the plant in the soil. Their formation involves the precise control of cell fate and localized cell growth. We are now beginning to unravel the complexities of the molecular interactions that underlie this developmental regulation. In addition, after years of speculation, nutrient transport by root hairs has been demonstrated clearly at the physiological and molecular level, with evidence for root hairs being intense sites of H(+)-ATPase activity and involved in the uptake of Ca(2+), K(+), NH(4)(+), NO(3)(-), Mn(2+), Zn(2+), Cl(-) and H(2)PO(4)(-).

  8. Role of Wnt and Notch signaling in regulating hair cell regeneration in the cochlea.

    PubMed

    Waqas, Muhammad; Zhang, Shasha; He, Zuhong; Tang, Mingliang; Chai, Renjie

    2016-09-01

    Sensory hair cells in the inner ear are responsible for sound recognition. Damage to hair cells in adult mammals causes permanent hearing impairment because these cells cannot regenerate. By contrast, newborn mammals possess limited regenerative capacity because of the active participation of various signaling pathways, including Wnt and Notch signaling. The Wnt and Notch pathways are highly sophisticated and conserved signaling pathways that control multiple cellular events necessary for the formation of sensory hair cells. Both signaling pathways allow resident supporting cells to regenerate hair cells in the neonatal cochlea. In this regard, Wnt and Notch signaling has gained increased research attention in hair cell regeneration. This review presents the current understanding of the Wnt and Notch signaling pathways in the auditory portion of the inner ear and discusses the possibilities of controlling these pathways with the hair cell fate determiner Atoh1 to regulate hair cell regeneration in the mammalian cochlea. PMID:27527363

  9. Law in Outer Space.

    ERIC Educational Resources Information Center

    Schmidt, William G.

    1997-01-01

    Provides an overview of the current practice and fascinating future of legal issues involved in outer space exploration and colonization. Current space law, by necessity, addresses broad principles rather than specific incidents. Nonetheless, it covers a variety of issues including commercial development, rescue agreements, object registration,…

  10. Optical properties of human hair

    NASA Astrophysics Data System (ADS)

    Altshuler, Gregory B.; Ilyasov, Ildar K.; Prikhodko, Constantin V.

    1995-01-01

    Optical properties of human hair are the subject of great interest for the realization of any possible cosmetic applications. This paper represents the results of hair microstructure as an optical substance investigation, indicates melanin and keratin absorption spectra, and shows experimentally discovered anisotropia of optical properties of human hair. Radiation weakening coefficient value at the range from 450 up to 800 nm is estimated. Thresholds of hair destruction by Nd, Ho, Cu, and Er laser radiation are obtained. Perspectives of laser application for epilation and other medical purposes are evaluated.

  11. Nanomechanical responses of human hair.

    PubMed

    Samanta, Aniruddha; Bhattacharya, Manjima; Dalui, Srikanta; Acharya, Megha; Das, Pradip Sekhar; Chanda, Dipak Kr; Acharya, Saikat Deb; Sivaraman, Sankar Kalidas; Nath, Shekhar; Mandal, Ashok Kumar; Ghosh, Jiten; Mukhopadhyay, Anoop Kumar

    2016-03-01

    Here we report the first ever studies on nanomechanical properties e.g., nanohardness and Young׳s modulus for human hair of Indian origin. Three types of hair samples e.g., virgin hair samples (VH), bleached hair samples (BH) and Fe-tannin complex colour treated hair samples (FT) with the treatment by a proprietary hair care product are used in the present work. The proprietary hair care product involves a Fe-salt based formulation. The hair samples are characterized by optical microscopy, atomic force microscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy (EDAX) genesis line map, EDAX spot mapping, nanoindentation, tensile fracture, and X-ray diffraction techniques. The nanoindentation studies are conducted on the cross-sections of the VH, BH and FT hair samples. The results prove that the nanomechanical properties e.g., nanohardness and Young׳s modulus are sensitive to measurement location e.g., cortex or medulla and presence or absence of the chemical treatment. Additional results obtained from the tensile fracture experiments establish that the trends reflected from the evaluations of the nanomechanical properties are general enough to hold good. Based on these observations a schematic model is developed. The model explains the present results in a qualitative yet satisfactory manner. PMID:26719934

  12. Quantum hair and quantum gravity

    SciTech Connect

    Coleman, S. ); Krauss, L.M. ); Preskill, J. ); Wilczek, F. )

    1992-01-01

    A black hole may carry quantum numbers that are not associated with massless gauge fields, contrary to the spirit of the 'no-hair' theorems. The 'quantum hair' is invisible in the classical limit, but measurable via quantum interference experiments. Quantum hair alters the temperature of the radiation emitted by a black hole. It also induces non-zero expectation values for fields outside the event horizon; these expectation values are non-perturbative in [Dirac h], and decay exponentially far from the hole. The existence of quantum hair demonstrates that a black hole can have an intricate quantum-mechanical structure that is completely missed by standard semiclassical theory.

  13. Removing Pubic Hair (For Young Women)

    MedlinePlus

    ... the-counter “depilatories” or cream hair removers: This method of hair removal is painless, but it’s important ... the cloth strip is quickly pulled off. This method of hair removal usually stings (when the cloth ...

  14. Genetics Home Reference: keratoderma with woolly hair

    MedlinePlus

    ... Conditions keratoderma with woolly hair keratoderma with woolly hair Enable Javascript to view the expand/collapse boxes. ... Open All Close All Description Keratoderma with woolly hair is a group of related conditions that affect ...

  15. Hair growth promoting effect of Zizyphus jujuba essential oil.

    PubMed

    Yoon, Jung In; Al-Reza, Sharif M; Kang, Sun Chul

    2010-05-01

    This study was undertaken to examine the efficacy of essential oil from seeds of Zizyphus jujuba for its potential role on hair growth by in vivo method. Essential oil was applied at different concentrations (0.1%, 1% and 10%) over the shaved skin onto the backs of BALB/c mice and monitored for 21 days. After 21 days, mice treated with 1% and 10% of oil produced a greater effect on the length of hair which were measured to be 9.96 and 10.02 mm, respectively, as compared to the control (8.94 mm). We measured the weight of hair/cm(2) area of dorsal skin and also evaluated hair thickness and hair follicles microscopically after plucking the hair immediately from the shaved area of mice and found the best results for 1% of essential oil-treated mice. From this study, it is concluded that Z. jujuba essential oil possesses hair growth promoting activity. PMID:20206225

  16. Delineating immune-mediated mechanisms underlying hair follicle destruction in the mouse mutant defolliculated.

    PubMed

    Ruge, Fiona; Glavini, Aikaterini; Gallimore, Awen M; Richards, Hannah E; Thomas, Christopher P; O'Donnell, Valerie B; Philpott, Michael P; Porter, Rebecca M

    2011-03-01

    Defolliculated (Gsdma3(Dfl)/+) mice have a hair loss phenotype that involves an aberrant hair cycle, altered sebaceous gland differentiation with reduced sebum production, chronic inflammation, and ultimately the loss of the hair follicle. Hair loss in these mice is similar to that seen in primary cicatricial, or scarring alopecias in which immune targeting of hair follicle stem cells has been proposed as a key factor resulting in permanent hair follicle destruction. In this study we examine the mechanism of hair loss in GsdmA3(Dfl)/+ mice. Aberrant expression patterns of stem cell markers during the hair cycle, in addition to aberrant behavior of the melanocytes leading to ectopic pigmentation of the hair follicle and epidermis, indicated the stem cell niche was not maintained. An autoimmune mechanism was excluded by crossing the mice with rag1-/- mice. However, large numbers of macrophages and increased expression of ICAM-1 were still present and may be involved either directly or indirectly in the hair loss. Reverse transcriptase-PCR (RT-PCR) and immunohistochemistry of sebaceous gland differentiation markers revealed reduced peroxisome proliferator-activated receptor-γ (PPARγ), a potential cause of reduced sebum production, as well as the potential involvement of the innate immune system in the hair loss. As reduced PPARγ expression has recently been implicated as a cause for lichen planopilaris, these mice may be useful for testing therapies. PMID:21160494

  17. Desmoglein 4 is Regulated by Transcription Factors Implicated in Hair Shaft Differentiation

    PubMed Central

    Bazzi, Hisham; Demehri, Shadmehr; Potter, Christopher S.; Barber, Alison G.; Awgulewitsch, Alexander; Kopan, Raphael; Christiano, Angela M.

    2010-01-01

    The hair fiber is made of specialized keratinocytes, known as trichocytes, that primarily express hair keratins which are cemented by a multitude of keratin-associated proteins (KAPs). The hair keratins form the intermediate filament cytoskeleton of the trichocytes, which are linked to abundant cell-cell adhesion junctions, called desmosomes. Desmoglein 4 (DSG4) is the major desmosomal cadherin expressed in the hair shaft cortex where the hair keratins are highly expressed. In humans, mutations affecting either the hair keratins or DSG4 lead to beaded hair phenotypes with features of monilethrix. In this work, we postulated that the regulatory pathways governing the expression of hair shaft components, such as hair keratins and DSG4, are similar. Therefore, we studied the transcriptional regulation of DSG4 by transcription factors/pathways that are known regulators of hair keratin or KAP expression. We show that HOXC13, LEF1 and FOXN1 repress DSG4 transcription and provide in vitro and in vivo evidence correlating the Notch pathway with the activation and/or maintenance of DSG4 expression in the hair follicle. PMID:19683850

  18. Single hair transplantation using the Choi hair transplanter.

    PubMed

    Choi, Y C; Kim, J C

    1992-11-01

    A new procedure for single hair transplantation using the Choi hair transplanter is presented. This operation provides obvious cosmetic advantages in hairline refinement and the reconstruction of eyebrows, eyelashes, beards, and pubic escutcheon. The surgical technique is described in detail. PMID:1430550

  19. Hair cell regeneration: Look to the future

    NASA Astrophysics Data System (ADS)

    Rubel, Edwin W.

    2005-04-01

    Less than 2 decades ago it was discovered that birds can regenerate hair cells in the auditory and vestibular parts of the inner ear after the native hair cells are destroyed by exposure to excessive noise or by mechanical trauma of aminoglycoside antibiotics. This discovery issued in a new era of hearing research-it suggested that some day it may be possible to actually restore hearing in people with congenital or acquired hearing loss due to the degeneration of sensory cells or supporting cells in the inner ear. Fifteen years is a very short time in the history of science. Consider the fact that we have actively sought chemical treatments to prevent or cure cancers for well over a half century and the ``war on Cancer,'' resulted in enormous public and private support. Progress has been great, and some forms of cancer can be treated with great success, but the overall 5-year survival rates have only risen from about 50% to 63%. Progress will continue and many more forms of cancer will be cured and prevented during the next half century. Similarly, during the first 15 years of hair cell regeneration research enormous progress has been made, and we now know that postnatal mammalian ears have the capacity to produce new hair cells. We are indeed a long way from restoring hearing through hair cell regeneration, but the future is pretty clear. I will review the progress of this field with an eye toward the future and what it means for treatments of today. In particular, I will address the potential cost versus benefits of bilateral implantation when applied to babies and young children.

  20. Hair loss in women.

    PubMed

    Camacho-Martínez, Francisco M

    2009-03-01

    Female pattern hair loss (FPHL) is a clinical problem that is becoming more common in women. Female alopecia with androgen increase is called female androgenetic alopecia (FAGA) and without androgen increase is called female pattern hair loss. The clinical picture of typical FAGA begins with a specific "diffuse loss of hair from the parietal or frontovertical areas with an intact frontal hairline." Ludwig called this process "rarefaction." In Ludwig's classification of hair loss in women, progressive type of FAGA, 3 patterns were described: grade I or minimal, grade II or moderate, and grade III or severe. Ludwig also described female androgenetic alopecia with male pattern (FAGA.M) that should be subclassified according to Ebling's or Hamilton-Norwood's classification. FAGA.M may be present in 4 conditions: persistent adrenarche syndrome, alopecia caused by an adrenal or an ovarian tumor, posthysterectomy, and as an involutive alopecia. A more recent classification (Olsen's classification of FPHL) proposes 2 types: early- and late-onset with or without excess of androgens in each. The diagnosis of FPHL is made by clinical history, clinical examination, wash test, dermoscopy, trichoscan, trichograms and laboratory test, especially androgenic determinations. Topical treatment of FPHL is with minoxidil, 2-5% twice daily. When FPHL is associated with high levels of androgens, systemic antiandrogenic therapy is needed. Persistent adrenarche syndrome (adrenal SAHA) and alopecia of adrenal hyperandrogenism is treated with adrenal suppression and antiandrogens. Adrenal suppression is achieved with glucocorticosteroids. Antiandrogens therapy includes cyproterone acetate, drospirenone, spironolactone, flutamide, and finasteride. Excess release of ovarian androgens (ovarian SAHA) and alopecia of ovarian hyperandrogenism is treated with ovarian suppression and antiandrogens. Ovarian suppression includes the use of contraceptives containing an estrogen, ethinylestradiol, and a