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Results 301 - 350 of 1720
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Li H - - 2007
This study aimed to fabricate bulk nanostructured hydroxyapatite (HA) pellets with improved properties using spark plasma sintering (SPS) for orthopedic applications. Spray-dried nanostructured HA (nSD-HA) powders were consolidated using the rapid SPS processing. The SPS processed nSD-HA was characterized using Raman spectroscopy and field emission scanning electron microscopy (FESEM). Mechanical ...
Choi Eun-Young - - 2007
Cultivar differences in root elongation under B toxic conditions were observed in barley (Hordeum vulgare L.). A significant increase in the length and width of the root meristematic zone (RMZ) was observed in Sahara 3771 (B tolerant) when it was grown under excessive B concentration, compared to when grown at ...
Kwack Mi Hee - - 2008
Recent studies suggest that androgen-driven alteration to the autocrine and paracrine factors produced by scalp dermal papilla (DP) cells may be a key to androgen-potentiated balding. Here, we screened dihydrotestosterone (DHT)-regulated genes in balding DP cells and found that dickkopf 1 (DKK-1) is one of the most upregulated genes. DKK-1 ...
Ou Henry C HC Virginia Merrill Bloedel Hearing Research Center, University of Washington, Box 357923, Seattle, WA 98195, USA. - - 2007
We have used time-lapse imaging to study cisplatin-induced hair cell death in lateral line neuromasts of zebrafish larvae in vivo. We found that cisplatin-induced hair cell death occurred much more slowly than had been shown to occur in aminoglycoside-induced hair cell death. By prelabeling hair cells with FM1-43FX, and assessing ...
Jacques Bonnie E - - 2007
The mammalian auditory sensory epithelium (the organ of Corti) contains a number of unique cell types that are arranged in ordered rows. Two of these cell types, inner and outer pillar cells (PCs), are arranged in adjacent rows that form a boundary between a single row of inner hair cells ...
Ohashi-Ito Kyoko K Stanford University, Department of Biological Sciences, Stanford, CA 94305, - - 2007
Complex organisms consist of a multitude of cell types arranged in a precise spatial relation to each other. Arabidopsis roots generally exhibit radial tissue organization; however, within a tissue layer, cells are not identical. Specific vascular cell types are arranged in diametrically opposed longitudinal files that maximize the distance between ...
Kosaka Katsuko - - 2007
We analyzed the cellular composition of the juxtaglomerular region in the main olfactory bulb of C57B/6J strain mice, focusing on 1) the compartmental organization of the glomerulus and the presence of type 1 and 2 periglomerular cells, 2) the colocalization relationships among the 4 major chemically identified groups of periglomerular ...
Ohnishi Takahiro - - 2007
We analysed the lipopolysaccharide (LPS)-recognition mechanism in cells expressing TLR4 and CD14 but lacking MD-2. When TLR4 and CD14 were transiently expressed in HEK293 cells, cell-surface expression of TLR4 was observed, although the expression level was lower than that in cells coexpressing MD-2. We found that membrane CD14-TLR4 complexes were ...
Xu Xianfeng Morgan - - 2007
The Ran GTPase controls multiple cellular processes including nucleocytoplasmic transport, spindle assembly, and nuclear envelope (NE) formation [1-4]. Its roles are accomplished by the asymmetric distribution of RanGTP and RanGDP enabled by the specific locations of the Ran GTPase-activating protein RanGAP and the nucleotide exchange factor RCC1 [5-8]. Mammalian RanGAP1 ...
Ladrech Sabine - - 2007
Transdifferentiation of nonsensory supporting cells into sensory hair cells occurs naturally in the damaged avian inner ear. Such transdifferentiation was achieved experimentally in the cochlea of deaf guinea pigs through Atoh 1 gene transfection. Supporting cells may therefore serve as targets for transdifferentiation therapy. Supporting cells rapidly degenerate after hair ...
Yano Kanako - - 2007
In previous studies, using a membrane-permeable protease inhibitor, E-64d, we showed that autophagy occurs constitutively in the root cells of barley and Arabidopsis. In the present study, a fusion protein composed of the autophagy-related protein AtAtg8 and green fluorescent protein (GFP) was expressed in Arabidopsis to visualize autophagosomes. We first ...
Imin Nijat - - 2007
When the leaf explants of Medicago truncatula are placed on auxin medium they form root initials within a week. Our studies have shown that the cells associated with the veins are stimulated into division by the added auxin, forming what we called vein-derived cells (VDCs) that grow out into callus ...
Swarup Ranjan - - 2007
Ethylene represents an important regulatory signal for root development. Genetic studies in Arabidopsis thaliana have demonstrated that ethylene inhibition of root growth involves another hormone signal, auxin. This study investigated why auxin was required by ethylene to regulate root growth. We initially observed that ethylene positively controls auxin biosynthesis in ...
Puligilla Chandrakala C Section on Developmental Neuroscience, NIDCD/NIH, Bethesda, Maryland 20892, USA. - - 2007
Deletion of fibroblast growth factor receptor 3 (Fgfr3) leads to hearing impairment in mice due to defects in the development of the organ of Corti, the sensory epithelium of the Cochlea. To examine the role of FGFR3 in auditory development, cochleae from Fgfr3(-/-) mice were examined using anatomical and physiological ...
Hordichok Andrew J AJ Oregon Hearing Research Center, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, - - 2007
In many vertebrate inner ear sensory epithelia, dying sensory hair cells are extruded, and the apices of surrounding supporting cells converge to re-seal the epithelial barrier between the electrochemically-distinct endolymph and perilymph. These cellular mechanisms remain poorly understood. Dynamic microtubular mechanisms have been proposed for hair cell extrusion; while contractile ...
Tiede Stephan - - 2007
The discovery of epithelial stem cells (eSCs) in the bulge region of the outer root sheath of hair follicles in mice and man has encouraged research into utilizing the hair follicle as a therapeutic source of stem cells (SCs) for regenerative medicine, and has called attention to the hair follicle ...
Minoda Ryosei - - 2007
Sensorineural hearing loss, which is often caused by degeneration of hair cells in the auditory epithelium, is permanent because lost hair cells are not replaced. Several conceptual approaches can be used to place new hair cells in the auditory epithelium. One possibility is to enhance proliferation of non-sensory cells that ...
Mignone John L JL Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, - - 2007
The bulge region of the hair follicle serves as a repository for epithelial stem cells that can regenerate the follicle in each hair growth cycle and contribute to epidermis regeneration upon injury. Here we describe a population of multipotential stem cells in the hair follicle bulge region; these cells can ...
Soler Alejandro Peralta - - 2007
Melanocytic matricoma is a rare neoplasm thought to recapitulate the hair follicle in anagen. The tumor forms a nodule in the dermis containing basaloid, intermediate and shadow cells admixed with pigmented melanocytes dispersed as single dendritic cells. Because cadherins and catenins are crucial in the development of hair tumors, we ...
Owens Kelly N - - 2007
Loss of the mechanosensory hair cells in the auditory and vestibular organs leads to hearing and balance deficits. To investigate initial, in vivo events in aminoglycoside-induced hair cell damage, we examined hair cells from the lateral line of the zebrafish, Danio rerio. The mechanosensory lateral line is located externally on ...
Welkoborsky Hans-J HJ Department of Otorhinolaryngology Head and Neck Surgery, Nordstadt Clinic, Academic Hospital, Haltenhoffstr. 41, 30167, Hannover, - - 2007
In the clinical setting, pediatric cholesteatomas frequently behave more aggressively than similar lesions in adults. The reason for the difference in behavior is still unclear. The purpose of the present study was to investigate the cell to cell and epithelial-stroma interaction of acquired cholesteatoma in adults and children and search ...
Grant Lisa - - 2007
The sensory hair cells of the mammalian cochlea transduce acoustic stimuli into auditory nerve activity. The biomechanical and molecular details of hair cell mechanotransduction are being acquired at an ever-finer level of resolution. In this review, we discuss how selected mouse mutants and transgenic models have contributed to, and will ...
Hume Clifford R CR Department of Otolaryngology - Head and Neck Surgery, Virginia Merrill Bloedel Hearing Research Center, University of Washington, VMBHRC, CHDD, CD176, Box 357923, 1959 NE Pacific, Seattle, WA 98195, USA. - - 2007
A cascade of transcription factors is believed to regulate the coordinate differentiation of primordial inner ear cells into the subtypes of hair cells and supporting cells. While candidate genes involved in this process have been identified, the temporal and spatial patterns of expression of many of these have not been ...
Caicci F - - 2007
In ascidians, mechanoreceptors of the oral area are involved in monitoring the incoming water flow. Sensory cells are represented by scattered, ciliated primary cells (sending their own axons to the cerebral ganglion) or secondary sensory cells (axonless cells forming afferent and efferent synapses with neurons, whose somata are located in ...
Zhang Yuan - - 2007
Mammalian cochlear hair cell loss is irreversible and leads to permanent hearing loss. To restore hearing physiologically, it is necessary to generate new functional hair cells either from endogenous cells or from exogenously transplanted hair cells/progenitors. Previous studies suggest that cochlear greater epithelial ridge (GER) and lesser epithelial ridge (LER) ...
Moore Christopher A - - 2007
The purpose of this study was to determine the acute effects of a spectrum of eccentric loads on force, velocity, and power during the concentric portion of maximal-effort jump squats utilizing a repeated measures design. Thirteen resistance-trained men (age = 22.8 +/- 2.9 years, weight = 87.1 +/- 11.8 kg, ...
Kang Yun - - 2007
In broad bean (Vicia faba L.), an apoplastic phloem loader, the sucrose concentration increases up to approximately 2 mM in the leaf apoplast and up to approximately 150 mM in the guard-cell apoplast during the photoperiod. This high concentration in the guard-cell apoplast results from transpiration and is sufficient osmotically ...
Osada Aki - - 2007
We have succeeded in culturing dermal papilla (DP) cells long term and developed new techniques that enhance their hair follicle-inducing efficiency in a patch assay. The outgrowing DP cells from mouse vibrissae were markedly stimulated by 10% fetal bovine serum-Dulbecco's modified essential medium that included fibroblast growth factor-2 (FGF-2). Moreover, ...
Caro Elena - - 2007
Cell proliferation and cell fate decisions are strictly coupled processes during plant embryogenesis and organogenesis. In the Arabidopsis thaliana root epidermis, expression of the homeobox GLABRA2 (GL2) gene determines hair/non-hair cell fate. This requires signalling of positional information from the underlying cortical layer, complex transcriptional regulation and a change in ...
Meyers Jason R - - 2007
Mature mammals are uniquely vulnerable to permanent auditory and vestibular deficits, because the cell proliferation that produces replacement hair cells in other vertebrates is limited in mammals. To investigate the cellular mechanisms responsible for that difference, we created excision lesions in the sensory epithelium of embryonic and 2-week-old mouse utricles. ...
Chrostek-Grashoff, Anna Magdalena
Rac1 is a ubiquitously expressed member of the Rho family of small GTPases, which acts as a molecular switch by shuttling in a highly regulated manner between an active (GTP-bound) and an inactive (GDP-bound) state. Different signalling pathways, which involve integrins, growth factor receptors, cadherins as well as other Rho ...
Ehama Ritsuko - - 2007
Hair follicle regeneration involves epithelial-mesenchymal interactions (EMIs) of follicular epithelial and dermal papilla (DP) cells. Co-grafting of those cellular components from mice allows complete hair reconstitution. However, regeneration of human hair in a similar manner has not been reported. Here, we investigated the possibility of cell-based hair generation from human ...
Chen Guang-Di - - 2007
It is known that styrene is ototoxic and causes cochlear damage starting from the middle turn. However, the cellular mechanism underlying styrene ototoxicity is still unclear. In this study, rats were exposed to styrene by gavage at different doses once a day for varying periods. Styrene levels in the cochlear ...
Hernández Pedro P - - 2007
Mechanosensory hair cells are essential for audition in vertebrates, and in many species, have the capacity for regeneration when damaged. Regeneration is robust in the fish lateral line system as new hair cells can reappear after damage induced by waterborne aminoglycoside antibiotics, platinum-based drugs, and heavy metals. Here, we characterize ...
Bergman David J - - 2007
We propose that social hornets and bees, who construct large arrays (known as combs) of cells for hatching and brooding their offspring, exploit ultrasonic acoustic resonances in those cells in order to implement the accurate honeycomb structure exhibited by those arrays. This idea is supported by a number of theoretical ...
Sekijima, Masanori
Biosociological studies on Parapolybia indica SAUSSURE have been carried out by the authors since 1976. The present paper deals with the nesting habits and brood devel opment of this wasp in Kawakita, Tsu, Mie Pref., southern Japan, in comparison with those of other Polistinae. Some peculiar habits on nidification are ...
Deans Michael R - - 2007
Vestibular hair cells have a distinct planar cell polarity (PCP) manifest in the morphology of their stereocilia bundles and the asymmetric localization of their kinocilia. In the utricle and saccule the hair cells are arranged in an orderly array about an abrupt line of reversal that separates fields of cells ...
Kashiwagi Mariko - - 2007
Using conditional gene targeting in mice, we show that the chromatin remodeler Mi-2beta is crucial for different aspects of skin development. Early (E10.5) depletion of Mi-2beta in the developing ventral epidermis results in the delayed reduction of its suprabasal layers in late embryogenesis and to the ultimate depletion of its ...
Buckiova Daniela - - 2007
The Fischer 344 rat strain has been frequently used as an animal model of rapid aging. The present study was aimed at evaluating the incidence of apoptotic cells in the inner ear of 20-24-month-old F344 rats and to correlate it with cochlear function using otoacoustic emissions. Staining with cresyl violet ...
Matsuhashi Sachiko - - 2007
Expression of a tumor suppressor gene, programmed cell death 4 (PDCD4), was investigated at the protein level in the human skin. Immunohistochemically, PDCD4 protein expressed mainly in suprabasal layers, while PDCD4-positive and -negative areas were observed discontinuously in the basal cell layer of the epidermis. In hair follicles, the suprabulbar ...
Sugawara Mitsuru - - 2007
Recent studies indicate that neurotrophin 3 (NT3) may be important for the maintenance and function of the adult inner ear, but the pattern of postnatal NT3 expression in this organ has not been characterized. We used a reporter mouse in which cells expressing NT3 also express beta-galactosidase, allowing for their ...
Gu Rende - - 2007
Millions of lives are affected by hearing and balance deficits that arise as a consequence of sensory hair cell loss. Those deficits affect mammals permanently, but hearing and balance recover in nonmammals after epithelial supporting cells divide and produce replacement hair cells. Hair cells are not effectively replaced in mammals, ...
Kim Young Ho - - 2007
Quiescence is among the hallmarks of the sensory epithelium of the cochlea. When auditory sensory cells (hair cells) degenerate they are not replaced, and therefore hearing loss is permanent. Cochlear hair cells are susceptible to several types of lesions, including aminoglycoside antibiotics. The application of the aminoglycoside neomycin in the ...
Cho Hyung-Taeg - - 2007
Three types of root hair cell distribution patterns are observed in vascular plants. These distinctive patterning types indicate that the fate of the hair/nonhair cell of the root epidermis in each of these patterns is decided by different fate-determining machineries. The cell fate determiners ultimately control the hair or nonhair ...
Boger, Erich
Recessive mutations of MYO15A encoding unconventional myosin XVA are associated with sensorineural deafness in both humans (DFNB3) and the shaker 2 phenotype in mice, which are deaf and exhibit circling behavior due to a vestibular abnormality. Myosin XVa is extensively alternatively spliced and encodes approximately thirty protein isoforms. In mouse ...
Du Xiaoping - - 2007
The transcription factor Math1 has been shown to be critical in the formation of hair cells (HCs) in the inner ear. However, the influence of environmental factors in HC specification suggests that cell extrinsic factors are also crucial to their development. To test whether extrinsic factors impact development of Math1-null ...
Lou Xiangxin - - 2007
The terminal mitosis of hair cells (HCs) and supporting cells (SCs) in mammalian cochlea occurred during middle embryonic development. Most hearing loss results from the incapacity of the cochlear sensory epithelium to replace lost hear cells. Deafness due to hair cells loss is normally irreversible. The present study showed that ...
Herr Deron R - - 2007
Hearing requires the transduction of vibrational forces by specialized epithelial cells in the cochlea known as hair cells. The human ear contains a finite number of terminally differentiated hair cells that, once lost by noise-induced damage or toxic insult, can never be regenerated. We report here that sphingosine 1-phosphate (S1P) ...
Laine Heidi - - 2007
Sensory hair cells of the auditory organ are generated during embryogenesis and remain postmitotic throughout life. Previous work has shown that inactivation of the cyclin-dependent kinase inhibitor (CKI) p19(Ink4d) leads to progressive hearing loss attributable to inappropriate DNA replication and subsequent apoptosis of hair cells. Here we show the synergistic ...
Hayashi Toshinori - - 2007
Previous studies have demonstrated the importance of FGF signaling at several stages in the development of the cochlea. At early stages of embryogenesis, Fgfr1, Fgfr2, and several FGFs are critical for both the induction of the otic vesicle and the initial development of the sensory epithelium. At late stages of ...
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