We have investigated the structural events associated with vacuole biogenesis in root tip cells of tobacco (Nicotiana tabacum) seedlings preserved by high-pressure freezing and freeze-substitution techniques. Our micrographs demonstrate that the lytic vacuoles (LVs) of root tip cells are derived from protein storage vacuoles (PSVs) by cell type-specific sets of ...

This study describes a novel cytoskeletal array in fiber cells of the ocular lens of the rat and shows its relationship to the classical terminal web of other epithelial tissues. Naive adult Sprague-Dawley rats (n = 28) were utilized. F-actin, fodrin, myosin IIA, and CP49 distribution was assessed in anterior ...

Defined electrospinning conditions were used to create scaffolds with different fiber diameters to investigate their interactions with osteoblastic MG63 cells. Nonwoven gelatin scaffolds were electrospun with varied fiber diameters to investigate the effect of fiber size and resultant porosity on cell proliferation, viability, migration, and differentiation. The low toxicity solvent ...

We report the production of chitosan-based fibers and chitosan fiber-mesh structures by melt processing (solvent-free) to be used as tissue-engineering scaffolds. The melt-based approach used to produce the scaffolds does not change their main characteristics, including the surface roughness and microporosity. The porosity, pore size, interconnectivity and mechanical performance of ...

Vacuolar invertase (VIN) has long been considered as a major player in cell expansion. However, direct evidence for this view is lacking due, in part, to the complexity of multicellular plant tissues. Here, we used cotton (Gossypium spp.) fibers, fast-growing single-celled seed trichomes, to address this issue. VIN activity in ...

Lens regeneration among vertebrates is basically restricted to some amphibians. The most notable cases are the ones that occur in premetamorphic frogs and in adult newts. Frogs and newts regenerate their lens in very different ways. In frogs the lens is regenerated by transdifferentiation of the cornea and is limited ...

A 3-day-old, male red deer (Cervus elaphus) with bilateral microphthalmia was found dead in the Western Alps in northern Italy. No other gross alterations were present. Ocular globes were formalin fixed and processed for histology. In both eyes, a large cyst, filled with keratin and lined by squamous epithelium admixed ...

Topographical features, including fiber dimensions and pattern, are important aspects in developing fibrous scaffolds for tissue engineering. In this study aligned poly(l-lactide) (PLLA) fibers with diameters of 307+/-47, 500+/-53, 679+/-72 and 917+/-84 nm and random fibers with diameters of 327+/-40, 545+/-54, 746+/-82 and 1150+/-109 nm were obtained by optimizing the ...

PURPOSE: Prior structural studies of posterior subcapsular cataract (PSC) development in Royal College of Surgeons (RCS) rats suggest that migration of basal fiber ends was disrupted, ultimately resulting in a PSC. Therefore the goal of this study was to assess the overall migration patterns as well as changes to the ...

PURPOSE: The aim of this study was to investigate the capabilities of laser scanning confocal microscopy (LSCM) for undertaking qualitative and quantitative investigations of the response of the bulbar conjunctiva to contact lens wear. METHODS: LSCM was used to observe and measure morphological characteristics of the bulbar conjunctiva of 11 ...

Planar cell polarity (PCP) signaling polarises cells along tissue axes. Although pathways involved are becoming better understood, outstanding issues include; (i) existence/identity of cues that orchestrate global polarisation in tissues, and (ii) the generality of the link between polarisation of primary cilia and asymmetric localisation of PCP proteins. Mammalian lenses ...

Hydrogen peroxide (H2O2) is the major oxidant involved in cataract formation. The present study investigated the effect of an aqueous leaf extract of Tulsi (Ocimum sanctum) against H2O2 induced cytotoxic changes in human lens epithelial cells (HLEC). Donor eyes of the age range 20-40 years were procured within 5-8 h ...

The mechanism of biospinning of natural silk fibers has been an open issue for decades. In this report a natural bio-polymeric matrix based on biospun silk fibers obtained from Antheraea mylitta, a wild non-mulberry tropical tasar silkworm, is put forward for potential applications. This report deals with the conformational transitions ...

PURPOSE: To optimize fixation, sectioning, and immunolabeling protocols to map the morphology of the human lens with confocal microscopy. METHODS: Transparent human lenses were fixed in 0.75% paraformaldehyde for 24 hours, cut in half, and fixed for another 24 hours. Lenses were cryoprotected, sectioned, and labeled with wheat germ agglutinin, ...

The development of the eye of the oviparous brown banded bamboo shark, Chiloscyllium punctatum, was monitored from egg deposition through adulthood. The order and timing of retinal cell differentiation were assessed by light and transmission electron microscopy. As in other vertebrates, the ganglion cells are the first to differentiate, in ...

One of the reasons that the crystalline lenses of vertebrate eyes are highly transparent is that most of the cells have broken down all of their organelles, including the nuclei. These cells can neither synthesize new proteins nor generate energy by electron transport in the mitochondria. Only in the peripheral ...

Conventional alginate/poly-L-ornithine (AP) membranes used to immunoisolate foreign tissue transplants fail in long-term transplantations of immortal cell lines. We have developed a novel layer-by-layer (LbL) membrane using polystyrene sulfonate and polyallylamine hydrochloride (PSS/PAH) on top of the coherent AP membrane. Assembly of the LbL membrane was followed by electrophoresis, and ...

PURPOSE: It was determined in an earlier study that ferritin-heavy (H) and -light (L) chains in lens fiber cells are modified in comparison to those in lens epithelial cells. The purpose of the present study was to determine whether changes in ferritin chain characteristics are developmental, age-related, or associated with ...

Studies using conventional electron microscopy describe the cytoplasm of lens fiber cells as having essentially an amorphous structure. We hypothesized that significant structural detail might have been lost as a result of projecting the entire thickness of the section (50-100 nm) onto a single plane (the "projection artifact"). To test ...

Gram-negative bacteria assemble functional amyloid surface fibers called curli. CsgB nucleates the major curli subunit protein, CsgA, into a self-propagating amyloid fiber on the cell surface. The CsgG lipoprotein is sufficient for curlin transport across the outer membrane and is hypothesized to be the central molecule of the curli fiber ...

Using immunohistochemistry and mass spectrometry, differentiation-dependent changes in the subcellular distribution and processing of aquaporin-0 (AQP0) have been mapped in the rat lens. Sections labelled with C-terminal tail AQP0 antibodies yielded two concentric rings of labelling with minimal signal in the lens core. The rings were separated by a transient ...

BASP1 was detected in the embryonic and adult chicken lens, using immunological methods and by peptide sequence analysis. The protein was predominantly expressed in fiber cells and only faintly detected in annular pad cells. Localization of the protein was along the plasma membrane of fiber cells often in discrete areas. ...

To measure the effects of long-term wear of soft lenses of low and high oxygen transmissibility (Dk) on basal epithelial appearance and epithelial thickness. Sixty-three subjects were enrolled in a cross-sectional study. Seventeen high Dk lens wearers and 24 low Dk lens wearers who had worn lenses on an extended ...

Poly(lactide-co-glycolide) (PLGA) scaffolds prepared by the electrospinning technology were paid more attention in tissue engineering, but detailed investigation on the influence of process parameters on scaffold morphology and fiber diameters as well as distribution remains to be conducted. In the current study, PLGA concentration, electric field strength, and feeding rate ...

How an organ develops its characteristic shape is a major issue. This is particularly critical for the eye lens as its function depends on having appropriately ordered three-dimensional cellular architecture. Recent in vitro studies indicate that Wnt signaling plays key roles in regulating morphological events in FGF-induced fiber cell differentiation ...

The primary goal was to characterize the structural alterations that occur at the fiber cell interfaces in nuclei of fully opaque cataracts removed by extracapsular cataract surgery in India. The dark yellow to brunescent nuclei, ages 38-78 years, were probably representative of advanced age-related nuclear cataracts. Thick tissue slices were ...

The aquaporins (AQPs) are integral membrane proteins whose main function is to transport water across cell membranes in response to osmotic gradients. At the ocular surface, AQP1 is expressed in corneal endothelium, AQP3 and AQP5 in corneal epithelium, and AQP3 in conjunctival epithelium. AQPs are also expressed in lens fiber ...

Extracellular ATP has been shown to mobilize intracellular Ca(2+) in cultured ovine lens epithelial cells and in human lens epithelium, suggesting a role for purines in the modulation of lens transparency. In this study, we characterized the expression profiles of P2Y receptor isoforms throughout the rat lens at both the ...

The lens epithelium possesses an apical junctional complex (AJC) comprising adherens and tight junctions (AJs and TJs) and yet several key structural components and associated regulatory proteins have not been identified or localised in these cells. Here we determine the subcellular distribution of the archetypal TJ markers (ZO-1, claudin-1, and ...

Lens transparency and high refractive index presumably depend on the appropriate arrangement and distribution of lens proteins among lens fiber cells. Intercellular gap junction channels formed by alpha3 and alpha8 connexins are known to transport small molecules, ions and water, but not proteins, in the lens. Mosaic expression of green ...

Impedance measurements in whole lenses showed that lens fiber cells possess different permeability properties to the epithelial cells from which they differentiate. To confirm these observations at the cellular level, we analyzed the membrane properties of fiber cells isolated in the presence of the nonselective cation channel inhibitor Gd3+. Isolated ...

PURPOSE: The beaded filament is a cytoskeletal structure that has been found only in the lens fiber cell. It includes phakosin and filensin, two divergent members of the intermediate filament family of proteins that are also unique to the fiber cell. The authors sought to determine what function the beaded ...

In the present paper, juvenile and adult shells of the green ormer Haliotis tuberculata ('Oreille de Saint-Pierre') were perforated in a zone close to the shell edge and the shell repair process was followed at two levels: (1) by observing the histology of the calcifying mantle in the repair zone ...

We evaluated the gross morphology, location, and fiber cell architecture of equatorial cortical opacities in the aging human lens. Using dark-field stereomicroscopy, we photographed donor lenses in toto and as thick slices. In addition, we investigated the details of the fiber cell architecture using fluorescent staining for membranes and by ...

Coaxial electrospinning is a new technique to fabricate continuous composite ultrafine fibers with core/shell structure, which has a broad application perspective in the biomedical field. In this study, ultrafine fibrous membranes of core/shell poly(vinyl pyrrolidone)/poly(L-lactide-co-epsilon-caprolactone) (PVP/PLCL) were produced by coaxial electrospinning and the structural morphology of the obtained ultrafine fibers ...

PURPOSE: To investigate the functional significance of MIP/AQP0 phosphorylation at serine(235). METHODS: MIP/AQP0 expression and cellular localization was studied in rat lens epithelia explants induced to differentiate by FGF-2. MIP wild type (WT) and MIP (S235A) mutant expression plasmids were constructed and transiently expressed in RK13 cells. Subcellular localization of ...

PURPOSE: Asymmetric cell division (ACD) is the fundamental mechanism underlying the generation of cellular diversity in invertebrates and vertebrates. During Drosophila neuroblast division, this process involves stabilization of the apical complex and interaction between the Inscuteable (Insc) and Partner of inscuteable (Pins) proteins. Both cell-intrinsic factors and cell-cell interactions seem ...

Fgf signaling plays crucial roles in morphogenesis. Fgf19 is required for zebrafish forebrain development. Here, we examined the roles of Fgf19 in the formation of the lens and retina in zebrafish. Knockdown of Fgf19 caused a size reduction of the lens and the retina, failure of closure of the choroids ...

The toxicity of mineral fibers, whether they are natural or man made (MMMF), is usually evaluated in vivo using biopersistence tests in rodents. Development of an in vitro cellular model would be worthwhile in order to reduce, refine and finally replace animal models. For this purpose, we developed an in ...

Hollow fiber scaffolds that compartmentalize axonal processes from their cell bodies can enable neuronal cultures with directed neurite outgrowth within a three-dimensional (3-D) space for controlling neuronal cell networking in vitro. Controllable 3-D neuronal networks in vitro could provide tools for studying neurobiological events. In order to create such a ...

We previously reported that, among the three connexins expressed in chick lens, overexpression of connexin (Cx) 45.6, not Cx43 or Cx56, stimulates lens cell differentiation; however, the underlying mechanism responsible for this effect is unclear. Here, we took advantage of naturally occurring loss-of-gap-junction function mutations of Cx50 (ortholog of chick ...

Field-grown poplar trees (Populus nigra L. x P. maximowiczii Henry, clone Kamabuchi) were exposed to severe drought twice during the growing season to evaluate the impact on wood cell development. The drought treatment caused a reduction in leaf water potential, leaf wilting and a decreased concentration of osmotically active solutes ...

Recent studies of the distribution and relative concentration of caveolin-1 in fractions of bovine lens epithelial and fiber cells have led to the novel concept that caveolin-1 may largely exist as a peripheral membrane protein in some cells. Caveolin-1 is typically viewed as a scaffolding protein for caveolae in plasma ...

Velvet leaf (Abutilon theophrasti) that is currently considered a weed and an agricultural problem could be used as a source for high quality natural cellulose fibers. The fibers obtained from the velvet leaf stems are mainly composed of approximately 69% cellulose and 17% lignin. The single cells in the fiber ...

The effect of added dispersing agent tetrasodium pyrophosphate (TSP) on the degradation of phenol by Pseudomonas putida BCRC 14365 in a microporous membrane bioreactor was experimentally studied at 30 degrees C and pH 7. The hollow fibers were pre-wetted with ethanol to make them more hydrophilic. Phenol solution was passed ...

PURPOSE: In this study recessive zebrafish mutations in the genes encoding laminin beta1 (lamb1) and laminin gamma1 (lamc1) were used to determine the functions of these laminin proteins during ocular basement membrane formation and during zebrafish eye development. METHODS: Ocular defects in lamb1 and lamc1 mutants were characterized by using ...

INTRODUCTION: The objective was to study the pathogenesis of contact lens-associated giant papillary conjunctivitis (CL-GPC). MATERIALS AND METHODS: Twenty-one biopsies of conjunctival giant papillae were obtained from soft contact lens wearers. The tissues were fixed in 4% paraformaldehyde and embedded in paraffin. Sections of 5 microm thickness were used for ...

Myosin II, a molecular motor, plays a critical role in cell migration, cell shape changes, cell adhesion, and cytokinesis. To understand the role of myosin II in lens fiber cell elongation and differentiation, we determined the distribution pattern of nonmuscle myosin IIA, IIB, and phosphorylated regulatory myosin light chain-2 (phospho-MLC) ...

Bone-like apatite coating of polymeric substrates by means of biomimetic process is a possible way to enhance the bone bonding ability of the materials. The created apatite layer is believed to have an ability to provide a favorable environment for osteoblasts or osteoprogenitor cells. The purpose of this study is ...

PURPOSE: To characterize the transcytotic passage of albumin through lens epithelial cells. METHODS: N/N 1003A rabbit lens epithelial cells were grown to a confluent monolayer on porous filter supports (Transwell Corning, Inc., Corning, NY). Monolayers were exposed apically to Alexa 488-labeled albumin (Alexa 488-BSA) in the absence and presence of ...