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Results 701 - 750 of 1719
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Klymchuk D O - - 2003
Changes in the vacuolation in root apex cells of soybean (Glycine max L. [Merr.]) seedlings grown in microgravity were investigated. Spaceflight and ground control seedlings were grown in the absence or presence of KMnO4 (to remove ethylene) for 6 days. After landing, in order to study of cell ultrastructure and ...
Wallis Deeann - - 2003
Gfi1 was first identified as causing interleukin 2-independent growth in T cells and lymphomagenesis in mice. Much work has shown that Gfi1 and Gfi1b, a second mouse homolog, play pivotal roles in blood cell lineage differentiation. However, neither Gfi1 nor Gfi1b has been implicated in nervous system development, even though ...
Hoshino M - - 2003
Signal transmission from a chick hair cell to the growth cone of a vestibular ganglion cell was examined by placing an acutely dissociated hair cell on the growth cone of a cultured vestibular ganglion cell. Electrical stimuli were applied to the hair cell while monitoring the intracellular Ca(2+) concentration ([Ca(2+)](i)) ...
Rodríguez-Llorente Ignacio D - - 2003
Tip growth is a specialized type of polar growth where new cell wall is deposited in a localized region of the cell, the growing tip. These cells show a characteristic zonation, with a high accumulation of secretory vesicles containing cell wall components at the tip, followed by an organelle-enriched zone. ...
Spector Alexander A - - 2003
The low-pass voltage response of outer hair cells predicted by conventional equivalent circuit analysis would preclude the active force production at high frequencies. We have found that the band pass characteristics can be improved by introducing the piezoelectric properties of the cell wall. In contrast to the conventional analysis, the ...
Takumida Masaya - - 2003
OBJECTIVE: In order to devise a new treatment for inner ear disorders, the efficacy of a nitric oxide synthase inhibitor (L-N(G)-nitroarginine methylester [L-NAME]), a radical scavenger (D-methionine), a neurotrophin (brain-derived neurotrophic factor [BDNF]) and a calpain inhibitor (leupeptin) for protection from hair cell damage was investigated. MATERIAL AND METHODS: The ...
Ramakrishnan Neeliyath A - - 2002
Full-length sequence (>6.5 kb) has been determined for the Ca(V)1.3 pore-forming subunit of the voltage-gated Ca(2+) channel from the saccular hair cells of the rainbow trout (Oncorhynchus mykiss). Primary structure was obtained from overlapping PCR and cloned fragments, amplified by primers based on teleost, avian, and mammalian sources. Trout saccular ...
Taniguchi Masafumi - - 2002
The mechanisms of cochlear hair cell death following exposure to transient inner ear ischemia were investigated in gerbils histologically. The animals were subjected to ischemic insult by occluding both vertebral arteries for 15 min. Hoechst 33342 nuclear staining showed that inner hair cells (IHCs) underwent sporadic degeneration via nuclear condensation, ...
Yamasoba Tatsuya - - 2002
Inoculation of adenovirus vectors in vivo has induced transgene expression in a variety of cochlear cells, but not hair cells or supporting cells in most previous studies. Specific hair cell inoculation by viral vectors has not been demonstrated in the mature guinea pig cochlea in vitro. We injected an Adex1CAlacZ ...
Kanzaki Sho - - 2002
As with other cranial nerves and many CNS neurons, primary auditory neurons degenerate as a consequence of loss of input from their target cells, the inner hair cells (IHCs). Electrical stimulation (ES) of spiral ganglion cells (SGCs) has been shown to enhance their survival. Glial cell line-derived neurotrophic factor (GDNF) ...
Ellengene H. Peterson,John R. ...
The vestibular system of vertebrates consists of the utricle, saccule, and the semicircular canals. Head movement causes deformation of hair cell bundles in these organs, which translate this mechanical stimulus into an electrical response sent to the nervous system.
Wada Takuji - - 2002
In Arabidopsis, root hairs are formed only from a set of epidermal cells named trichoblasts or hair-forming cells. Previous studies showed CAPRICE (CPC) promotes differentiation of hair-forming cells by controlling a negative regulator, GLABRA2 (GL2), which is preferentially expressed in hairless cells. Here, we show that CPC is also predominantly ...
Hennessey Todd M - - 2002
Cilia in many organisms undergo a phenomenon called ciliary reversal during which the cilia reverse the beat direction, and the cell swims backwards. Ciliary reversal is typically caused by a depolarizing stimulus that ultimately leads to a rise in intraciliary Ca++ levels. It is this increase in intraciliary Ca++ that ...
Bayer-Garner Ilene B - - 2002
Syndecan-1 is the prototypic member of a family of heparan sulfate-bearing cell surface proteoglycans that function in adhesion, cell-extracellular matrix interactions, migration, and proliferation. During embryogenesis, syndecan-1 expression in the epithelium is downregulated when the epithelium gives rise to motile mesenchymal cells, whereas mesenchymal syndecan-1 expression is upregulated during organ ...
Halpin Chris - - 2002
This article will explore the audiograms formed by the expected psychophysical thresholds from single, normally functioning inner hair cells. Like the audiogram formed by the vibrotactile response region, these psychophysical tuning curves represent fundamental limits in audiometry since they are the worst possible thresholds expected, even if no other cells ...
Cheng Alan G - - 2003
Caspases are a family of proteases that have been implicated as key mediators of cell death. Although nonspecific inhibition of caspase activation has been reported to prevent mammalian sensory hair cell death, the exact roles of individual caspases during hair cell death are unclear. In other systems, the activation of ...
Lewis Julian - - 2002
Sensory hair cells in the ear and lateral line have an asymmetrical hair-bundle structure, essential for their function as directional mechanotransducers. We examine four questions: (1) how does the planar asymmetry of the individual hair cell originate? (2) How are the orientations of neighboring hair cells coordinated? (3) How is ...
Mueller Kristen L - - 2002
One of the most striking aspects of the cellular pattern within the sensory epithelium of the mammalian cochlea is the presence of two rows of pillar cells in the region between the single row of inner hair cells and the first row of outer hair cells. The factors that regulate ...
Sobkowicz Hanna M HM Neurology Department, University of Wisconsin, 1300 University Avenue, Room 75 MSC, Madison 53706, USA. - - 2002
The Bronx waltzer (bv) deaf mouse is characterized by massive degeneration of the primary auditory receptors, the inner hair cells, which occurs during the time of expected afferent synaptogenesis. The process is associated with degeneration and protracted division of the normally postmitotic afferent spiral ganglion neurons. To investigate the potential ...
Das, S.
Mature stomata of four mangrove taxa of different families reveal three distinct types of stomatal complex on abaxial surfaces, such as diacytic (in Acanthus ilicifolius), anomocytic (in Aegialitis rotundifolia and Xylocarpus granatum), and paracytic (in Ceriops decandra). In transverse section, there is a beak-like cuticular outgrowth overarching the stomatal pore ...
Tiwari R K - - 2002
The haemopoietic organs in Vth instar larvae of P. demoleus are in the form of thin transparent cellular sheets, closely wrapped around the base of each wing-pad. Three cell types viz; prohaemocytes, plasmatocytes and oenocytoids appear to be derived from these organs and their ablation caused a reduction in cell ...
Malgrange B - - 2002
The organ of Corti is a complex structure containing a single row of inner hair cells (IHCs) and three rows of outer hair cells (OHCs), supported respectively by one row of inner phalangeal cells and three rows of Deiters' cells. When fetal rat organ of Corti explants are cultured, supernumerary ...
Chen Min - - 2002
A prerequisite for proteins to interact in a cell is that they are present in the same intracellular compartment. Although it is generally accepted that proteasomes occur in both, the cytoplasm and the nucleus, research has been focusing on cytoplasmic protein breakdown and antigen processing, respectively. Thus, little is known ...
Cunningham Lisa L - - 2002
Aminoglycoside exposure results in the apoptotic destruction of auditory and vestibular hair cells. This ototoxic hair cell death is prevented by broad-spectrum caspase inhibition. We have used in situ substrate detection, immunohistochemistry, and specific caspase inhibitors to determine which caspases are activated in the hair cells of the adult mouse ...
Hu Bo Hua - - 2002
Apoptosis is an active cell death pathway involved in a variety of pathological conditions, including noise-induced outer hair cell (OHC) death. During this process, the cytoskeletal proteins have been found to be either damaged and/or enzymatically disassembled in several cell types, leading to formation of apoptotic manifestations. This study was ...
Park Yong-Lak - - 2002
To quantify the damage caused by twospotted spider mite, Tetranychus urticae Koch, feeding on cucumber, Cucumis sativus L., leaf-cell and -tissue damage was assessed. On the abaxial leaf surface, adult T. urticae could feed through the spongy parenchyma and part of the palisade parenchyma of the leaf, while immature T. ...
Mylona Panagiota - - 2002
The primary root of Arabidopsis has a simple cellular organisation. The fixed radial cell pattern results from stereotypical cell divisions that occur in the meristem. Here we describe the characterisation of schizoriza (scz), a mutant with defective radial patterning. In scz mutants, the subepidermal layer (ground tissue) develops root hairs. ...
Kameda Takashi - - 2002
BACKGROUND: One of the most well-known ways to identify stem cells is to search for the slow-cycling cells (label-retaining cells; LRCs), by labelling their DNA. The bulge of hair follicle is assumed to identify the location of the follicular stem cells. While this assumption was supported by previous analyses of ...
Serrano Deborah Regina - - 2002
Since the internal defense system of mollusks consists of cellular and humoral mechanisms, we examined the role of hydrocortisone in mollusks defense cells and the influence of this steroid on the development of Schistosoma mansoni in its intermediary host. Hydrocortisone had an immunosuppressive action in Biomphalaria glabrata, as reflected in ...
Murray P E - - 2002
OBJECTIVES: Following tooth pulp exposure, pulpal repair is accomplished by dentine bridge secretion by odontoblast-like cells. However, little information is available about the hierarchy of variables, which influence odontoblast-like cell numbers. The purpose of this study was to examine correlations between pulp capping events and odontoblast-like cell numbers. METHODS: Two ...
Abbate F - - 2002
The distribution of S100 protein in the neuromast of the lateral line system (LLS) was investigated immunohistochemically in alevins of three species of teleosts (Salmo trutta, Salmo salar and Dicentrarchus labrax), using a polyclonal antibody. In both the neuromasts of the canals, as well as in the pit organs, the ...
Hukin D - - 2002
Root elongation occurs as individual cells along the growing zone increase in volume. This increase is caused by water entering the cell either by moving across the cell membrane from the apoplast via aquaporins, or entering through plasmodesmata that symplastically connect cells to each other or with the sieve element. ...
Hackett Lucy - - 2002
E-cadherin is expressed in vestibular, mechanosensory epithelia during early embryonic development. During late embryonic and neonatal stages it is expressed in supporting cells but down-regulated in differentiating sensory hair cells. We used a conditionally immortal cell line (UB/UE-1) from the neonatal mouse utricle to test the hypothesis that constitutive expression ...
Zine Azel - - 2002
The sensory epithelium of the mammalian cochlea (the organ of Corti) represents an excellent developmental system. The organ of Corti contains two main cell types: the sensory hair cells and the supporting cells which are organized in a defined mosaic pattern. Previous results have demonstrated the participation of Notch signaling ...
Ringli Christoph - - 2002
Root hairs develop as long extensions from root epidermal cells. After the formation of an initial bulge at the distal end of the epidermal cell, the root hair structure elongates by tip growth. Because root hairs are not surrounded by other cells, root hair formation provides an excellent system for ...
Schramm Vern L - - 2002
Newborns with a genetic deficiency of purine nucleoside phosphorylase (PNP) are normal, but exhibit a specific T-cell immunodeficiency during the first years of development. All other cell and organ systems remain functional. The biological significance of human PNP is degradation of deoxyguanosine, and apoptosis of T-cells occurs as a consequence ...
Cohen-Salmon Martine M Unité de Génétique des Déficits Sensoriels, CNRS URA 1968, Institut Pasteur, 25 rue du Dr. Roux, 75724 Paris cedex 15, - - 2002
Mutations in the gene encoding the gap junction protein connexin26 (Cx26) are responsible for the autosomal recessive isolated deafness, DFNB1, which accounts for half of the cases of prelingual profound hereditary deafness in Caucasian populations. To date, in vivo approaches to decipher the role of Cx26 in the inner ear ...
Oh Seung-Ha - - 2002
Auditory hair cells of birds, unlike hair cells in the mammalian organ of Corti, can regenerate following sound-induced loss. We have identified several genes that are upregulated following such an insult. One gene, WDR1, encodes the vertebrate homologue of actin-interacting protein 1, which interacts with actin depolymerization factor (ADF) to ...
Porter Rebecca M - - 2002
Defolliculated is a novel spontaneous mouse mutation that maps to chromosome 11 close to the type I keratin locus. Histology shows abnormal differentiation of the sebaceous gland, with the sebocytes producing little or no sebum and undergoing abnormal cornification. The hair follicles fail to regress during catagen leading to abnormally ...
Dehne N - - 2002
Aminoglycosides may induce irreversible hearing loss in both animals and humans. In order to study the nature and mechanisms underlying gentamicin-induced cell death in the inner ear, the cochlear neurosensory epithelia were dissected from guinea pigs and incubated with 0.5-10 mM gentamicin. Concentration-dependent loss of cell viability was detected by ...
Li Shengguo - - 2002
The cochlea of the mammalian inner ear contains three rows of outer hair cells and a single row of inner hair cells. These hair cell receptors reside in the organ of Corti and function to transduce mechanical stimuli into electrical signals that mediate hearing. To date, the molecular mechanisms underlying ...
Ando Motonori - - 2002
The cochlear stria vascularis produces the endolymph and generates the endocochlear DC potential, two indispensable ingredients of an auditory transduction process. The marginal cell, one of the several cell types constituting the stria vascularis, is called 'the dark cell' on the basis of its appearance by transmission electron microscopy (TEM). ...
Barclay A Neil - - 2002
OX2 (now designated CD200) is a membrane protein expressed by a broad range of cell types. It is the ligand for a receptor restricted to myeloid cells, with the potential to deliver inhibitory signals. This is indicated by the CD200-deficient mouse model, in which myeloid cells are more activated when ...
Higgs Dennis M - - 2002
Fishes, unlike most other vertebrate groups, continue to add sensory hair cells to their ears for much of their lives. However, it is not clear whether the addition ever stops or how the addition of sensory cells impacts hearing ability. In this article, we tested both questions using the zebrafish, ...
Knabel Michael - - 2002
Recently developed major histocompatibility complex (MHC) multimer technologies allow visualization and isolation of antigen-specific T cells. However, functional analysis and in vivo transfer of MHC multimer-stained cells is hampered by the persistence of T-cell receptor (TCR) MHC interactions and subsequently induced signaling events. As MHC monomers do not stably bind ...
Peters Eva M J - - 2002
Disruption of the c-Kit/stem cell factor (SCF) signaling pathway interferes with the survival, migration, and differentiation of melanocytes during generation of the hair follicle pigmentary unit. We examined c-Kit, SCF, and S100 (a marker for precursor melanocytic cells) expression, as well as melanoblast/melanocyte ultrastructure, in perinatal C57BL/6 mouse skin. Before ...
Zhai Suo-Qiang - - 2002
The purpose of this study was to observe the protective effects of basic fibroblast growth factor (bFGF) on the cells of the inner ear using in vivo experiments. The studies were carried out using guinea pigs in which bFGF or artificial perilymph was perfused into the cochlea. The compound action ...
McGowan Kevin M - - 2002
Onset of type I keratin 17 (K17) synthesis marks the adoption of an appendageal fate within embryonic ectoderm, and its expression persists in specific cell types within mature hair, glands, and nail. We report that K17 null mice develop severe alopecia during the first week postbirth, correlating with hair fragility, ...
Kato Takehide - - 2002
In higher plants, shoots and roots show negative and positive gravitropism, respectively. Data from surgical ablation experiments and analysis of starch deficient mutants have led to the suggestion that columella cells in the root cap function as gravity perception cells. On the other hand, endodermal cells are believed to be ...
He Biao - - 2002
The frizzled pathway in Drosophila has been studied intensively for its role in the development of planar polarity in wing hairs, thoracic bristles and ommatidia. Selected cells in the arista (the terminal segment of the antenna) elaborate a lateral projection that shares characteristics with both hairs and bristles. We found ...
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