Publications

gaba(a) receptor modulators from chinese herbal medicines traditionally applied against insomnia and anxiety.	several chinese herbal medicines (chms) are used in the treatment of insomnia, restlessness, or anxiety. however, mechanisms underlying this effect and scientific proof for their traditional use is scarce. in the present study chms were screened for their ability to modulate gaba-induced chloride currents (i(gaba)), and active principles were isolated thus providing scientific evidence for their use as sedative and/or anxiolytic agents in cm. herbal drugs were extracted successively with petrole ...	2011	22118921
a second base pair interaction between u3 small nucleolar rna and the 5'-ets region is required for early cleavage of the yeast pre-ribosomal rna.	in eukaryotes, u3 snorna is essential for pre-rrna maturation. its 5'-domain was found to form base pair interactions with the 18s and 5'-ets parts of the pre-rrna. in xenopus laevis, two segments of u3 snorna form base-pair interactions with the 5'-ets region and only one of them is essential to the maturation process. in saccharomyces cerevisiae, two similar u3 snorna-5' ets interactions are possible; but, the functional importance of only one of them had been tested. surprisingly, this intera ...	2011	21890904
role of the pi3k-tor-s6k pathway in the onset of cell cycle elongation during xenopus early embryogenesis.	in the early embryogenesis of the frog, xenopus laevis, cells proliferate by rapid and synchronous divisions, followed by cell cycle elongation and prolongation of the s phases, and then the appearance of the g2 and g1 phases after the midblastula transition (mbt). the beginning of cell cycle elongation was thought to depend on an increase in the nucleo-cytoplasmic (n/c) ratio in blastomeres and a decrease in cortical cytoplasmic factors necessary for cell cycle progression, although these facto ...	2011	21958163
a decrease in dkk1, a wnt inhibitor, contributes to placental lipid accumulation in an obesity-prone rat model.	placenta, as the sole transport mechanism between mother and fetus, links the maternal physical state and the immediate and life-long outcomes of the offspring. the present study examined the consequences of maternal obesity on placental lipid accumulation and metabolism. pregnant obesity prone (op) and obesity resistant (or) rat strains were fed a control diet throughout gestation. placentas were collected on gestational day 21 for mrna and oxidative stress analysis and frozen placental sectio ...	2011	22133691
Prominin-1 Localizes to the Open Rims of Outer Segment Lamellae in Xenopus laevis Rod and Cone Photoreceptors.	Purpose.Prominin-1 expresses in rod and cone photoreceptors. Mutations in the prominin-1 gene cause retinal degeneration in humans. In this study, we investigated the expression, subcellular localization of xlProminin-1 protein, the Xenopus laevis orthologue of prominin-1, in rod and cone photoreceptors of this frog.Methods.Antibodies specific for xlProminin-1 were generated. Immunoblotting was used to study the expression and posttranslational processing of xProminin-1 protein. Immunocytochemic ...	2011	22076989
expression analysis of the peroxiredoxin gene family during early development in xenopus laevis.	development in the frog, xenopus laevis, requires the utilization of yolk glyco-lipo-proteins in a temporally- and spatially-dependent manner. the metabolism of the yolk produces hydrogen peroxide (h(2)o(2)), a potent reactive oxygen species (ros). peroxiredoxins (prdxs) are a family of six anti-oxidant enzymes that, amongst other roles, reduce h(2)o(2). prdxs reduce h(2)o(2) through a thiol-redox reaction at conserved cysteine residues which results in the creation of disulfide bonds. recently ...	2011	21920462
The development of the adult intestinal stem cells: Insights from studies on thyroid hormone-dependent amphibian metamorphosis.	ABSTRACT: Adult organ-specific stem cells are essential for organ homeostasis and repair in adult vertebrates. The intestine is one of the best-studied organs in this regard. The intestinal epithelium undergoes constant self-renewal throughout adult life across vertebrates through the proliferation and subsequent differentiation of the adult stem cells. This self-renewal system is established late during development, around birth, in mammals when endogenous thyroid hormone (T3) levels are high. ...	2011	21896185
growth-arrest-specific protein 2 inhibits cell division in xenopus embryos.	growth-arrest-specific 2 gene was originally identified in murine fibroblasts under growth arrest conditions. furthermore, serum stimulation of quiescent, non-dividing cells leads to the down-regulation of gas2 and results in re-entry into the cell cycle. cytoskeleton rearrangements are critical for cell cycle progression and cell division and the gas2 protein has been shown to co-localize with actin and microtubules in interphase mammalian cells. despite these findings, direct evidence supporti ...	2011	21931817
optimization of gene delivery methods in xenopus laevis kidney (a6) and chinese hamster ovary (cho) cell lines for heterologous expression of xenopus inner ear genes.	the xenopus inner ear provides a useful model for studies of hearing and balance because it shares features with the mammalian inner ear, and because amphibians are capable of regenerating damaged mechanosensory hair cells. the structure and function of many proteins necessary for inner ear function have yet to be elucidated and require methods for analysis. to this end, we seek to characterize xenopus inner ear genes outside of the animal model through heterologous expression in cell lines. as ...	2011	21959846
jShaw1, a low-threshold, fast-activating K(v)3 from the hydrozoan jellyfish Polyorchis penicillatus.	Voltage-gated potassium (K(v)) channels work in concert with other ion channels to determine the frequency and duration of action potentials in excitable cells. Little is known about K(v)3 channels from invertebrates, but those that have been characterized generally display slow kinetics. Here, we report the cloning and characterization of jShaw1, the first K(v)3 isolated from a cnidarian, the jellyfish Polyorchis penicillatus, in comparison with mouse K(v)3.1 and K(v)3.2. Using a two-electrode ...	2011	21865525
temporal and spatial expression patterns of cdc25 phosphatase isoforms during early xenopus development.	in early animal development, cell proliferation and differentiation are tightly linked and coordinated. it is important, therefore, to know how the cell cycle is controlled during early development. cdc25 phosphatases activate cyclin-dependent kinases (cdks) and thereby promote cell-cycle progression. in xenopus laevis, three isoforms of cdc25 have been identified, viz. cdc25a, cdc25b and cdc25c. in this study, we isolated a cdna encoding a novel xenopus cdc25 phosphatase (named cdc25d). we inve ...	2011	21948711
nitric oxide as a putative retinal axon pathfinding and target recognition cue in xenopus laevis.	nitric oxide (no) is an atypical neurotransmitter synthesized by the enzyme nitric oxide synthase (nos) during many stages of the xenopus laevis life cycle. this research investigates whether the gas no is involved in axon guidance, the neurodevelopmental process in which axons travel through the brain to their appropriate target locations to form functional neural circuitry. through immunocytochemistry and direct labeling of the no gas with a fluorescent dye, we have found that nos expression c ...	2011	21847432
Molecular evolution of vertebrate sex-determining genes.	Y-linked Dmy (also called dmrt1bY) in the teleost fish medaka, W-linked Dm-W in the African clawed frog (Xenopus laevis), and Z-linked Dmrt1 in the chicken are all sex chromosome-linked Dmrt1 homologues required for sex determination. Dmy and Dm-W both are Dmrt1 palalogues evolved through Dmrt1 duplication, while chicken Dmrt1 is a Z-linked orthologue. The eutherian sex-determining gene, Sry, evolved from an allelic gene, Sox3. Here we analyzed the exon-intron structures of the Dmrt1 homologues ...	2011	22167552
characterization of two mutations, m287l and q266i, in the α1 glycine receptor subunit that modify sensitivity to alcohols.	glycine receptors (glyrs) are inhibitory ligand-gated ion channels. ethanol potentiates glycine activation of the glyr, and putative binding sites for alcohol are located in the transmembrane (tm) domains between and within subunits. to alter alcohol sensitivity of glyr, we introduced two mutations in the glyr α1 subunit, m287l (tm3) and q266i (tm2). after expression in xenopus laevis oocytes, both mutants showed a reduction in glycine sensitivity and glycine-induced maximal currents. activation ...	2011	22037201
xenopus staufen2 is required for anterior endodermal organ formation.	defining the regulatory molecular networks involved in patterning the developing anterior endoderm is essential to understanding how the pancreas, liver, stomach and duodenum are discretely specified from each other. in this study, we analyzed the expression and function of the double-stranded rna-binding protein staufen2 in xenopus laevis endoderm. we found that staufen2 was broadly expressed within the developing endoderm beginning at gastrulation becoming localized to the anterior endoderm at ...	2011	22162130
protein kinase c-dependent activation of human k(2p) 18.1 k(+) channels.	background and purpose. two-pore-domain potassium channels (k(2p) ) mediate k(+) background currents that modulate the membrane potential of excitable cells. k(2p) 18.1 (tresk, twik-related spinal cord k(+) channel) provides hyperpolarizing background currents in neurons. recently a dominant negative loss-of-function mutation in k(2p) 18.1 has been implicated in migraine, and activation of k(2p) 18.1 channels was proposed as therapeutic strategy. here we elucidate molecular mechanisms underly ...	2011	22168364
Single cysteines in the extracellular and transmembrane regions modulate pannexin 1 channel function.	Pannexins form high-conductance ion channels in the membranes of many vertebrate cells. Functionally, they have been associated with multiple functional pathways like the propagation of calcium waves, ATP release, responses to ischemic conditions and apoptosis. In contrast to accumulating details which uncovered their functions, the molecular mechanisms for pannexin channel regulation and activation are hardly understood. To further elucidate regulatory mechanisms, we substituted cysteine residu ...	2011	21938521
transdifferentiation from cornea to lens in xenopus laevis depends on bmp signalling and involves upregulation of wnt signalling.	surgical removal of the lens from larval xenopus laevis results in a rapid transdifferention of central corneal cells to form a new lens. the trigger for this process is understood to be an induction event arising from the unprecedented exposure of the cornea to the vitreous humour that occurs following lens removal. the molecular identity of this trigger is unknown.	2011	21896182
advances in the mode of action of pyrethroids.	the ability to clone, express, and electrophysiologically measure currents carried by voltage-gated ion channels has allowed a detailed assessment of the action of pyrethroids on various target proteins.recently, the heterologous expression of various rat brain voltage-gated sodium channel isoforms in xenopus laevis oocytes has determined a wide range of sensitivities to the pyrethroids, with some channels virtually insensitive and others highly sensitive. furthermore, some isoforms show selecti ...	2011	22025067
characterization of danio rerio nanog and functional comparison to xenopus vents.	nanog is a homeodomain transcription factor associated with the acquisition of pluripotency. genome analyses of lower and higher vertebrates revealed that the existence of nanog is restricted to gnathostomata but absent from agnatha and invertebrates. to elucidate the function of nanog in nonmammalia, we identified the danio rerio ortholog of nanog and characterized its role in gain and loss of function experiments. we found nanog to be crucial for survival of early zebrafish embryos, because de ...	2011	21967637
nuclear actin and transcriptional activation.	differentiated cells do not revert to an embryonic state in normal development. however, the method called nuclear reprogramming enables these differentiated cells to be reversed to an embryonic state. one essential event in the reprogramming process is reactivation of embryonic genes such as oct4 (also known as pou5f1). this reprogramming of transcriptional programs can be achieved by transplantation of mammalian somatic nuclei to the giant xenopus laevis oocyte nucleus, referred to as the germ ...	2011	22046469
jztx-xiii, a kv channel gating modifier toxin from chinese tarantula chilobrachys jingzhao.	jingzhaotoxin-xiii (jztx-xiii), a 35 residue polypeptide, with the ability to inhibit voltage-dependent potassium channels in the shab (kv2) and shal (kv4) subfamilies, was purified from the venom of the chinese tarantula chilobrachys jingzhao. electrophysiological recordings carried out in xenopus laevis oocytes showed that jztx-xiii acted as gating modifier of voltage-dependent k(+) channels which inhibited the kv2.1 channel and kv4.1 channel, with the ic(50) value of 0.47 μm and 1.17 μm, resp ...	2011	22155305
gravity-related critical periods in vestibular and tail development of xenopus laevis.	sensory systems are characterized by developmental periods during which they are susceptible to environmental modifications, in particular to sensory deprivation. the experiment, xenopus, on soyuz in 2008 was the fourth space flight experiment since 1993 to explore whether tail and vestibular development of xenopus laevis has a gravity-related critical period. during this flight, tadpoles were used that had developed either the early hindlimb (stage 47) or forelimb bud (stage 50) at launch of th ...	2011	21866581
the synthetic gestagen levonorgestrel disrupts sexual development in xenopus laevis by affecting gene expression of pituitary gonadotropins and gonadal steroidogenic enzymes.	in the present study, xenopus laevis tadpoles were chronically exposed to four concentrations of the synthetic gestagen levonorgestrel (lng; 10(-11), 10(-10), 10(-9), and 10(-8)m) starting at nieuwkoop and faber (nf) stage 48 until completion of metamorphosis. at nf 58 and 66, brain-pituitary and gonad samples were taken for gene expression analyses of gonadotropins and gonadal steroidogenic enzymes. exposure to 10(-9) and 10(-8)m lng until nf 58 repressed messenger rna (mrna) expression of lute ...	2011	21914719
[Synthesis, refolding and identification of pharmacological activities of neurotoxin JZTX-XI and R3A-JZTX-XI].	Kv2.1 channel currents in pancreatic beta-cells are thought to contribute to action potential repolarization and thereby modulate insulin secretion. Because of its central role in this important physiological process, Kv2.1 channel is a promising target for the treatment of type 2 diabetes. Jingzhaotoxin-XI (JZTX-XI) is a novel peptide neurotoxin isolated from the venom of the spider Chilobrachys jingzhao. Two-microelectrode voltage clamp experiments had showed that the toxin inhibited Kv2.1 pot ...	2011	22034819
deficient induction response in a xenopus nucleocytoplasmic hybrid.	incompatibilities between the nucleus and the cytoplasm of sufficiently distant species result in developmental arrest of hybrid and nucleocytoplasmic hybrid (cybrid) embryos. several hypotheses have been proposed to explain their lethality, including problems in embryonic genome activation (ega) and/or nucleo-mitochondrial interactions. however, conclusive identification of the causes underlying developmental defects of cybrid embryos is still lacking. we show here that while over 80% of both x ...	2011	22131902
atptr4 and atptr6 are differentially expressed, tonoplast-localized members of the peptide transporter/nitrate transporter 1 (ptr/nrt1) family.	members of the peptide transporter/nitrate transporter 1 (ptr/nrt1) family in plants transport a variety of substrates like nitrate, di- and tripepetides, auxin and carboxylates. we isolated two members of this family from arabidopsis, atptr4 and atptr6, which are highly homologous to the characterized di- and tripeptide transporters atptr1, atptr2 and atptr5. all known substrates of members of the ptr/nrt1 family were tested using heterologous expression in saccharomyces cerevisiae mutants and ...	2011	21904872
expression of periostin during xenopus laevis embryogenesis.	periostin (postn) is a secreted, extracellular matrix protein containing an emi domain as well as four fasciclin i-like (fas1) domains. postn protein functions in cell adhesion, cell mobility, cell proliferation and gene regulation. earlier studies have shown that postn is involved in different developmental processes such as somitogenesis, cardiogenesis and bone formation. intriguingly, postn seems to be a very good candidate to establish novel therapies against cancer and chronic heart defects ...	2011	21901578
substrate- and ph-specific antifolate transport mediated by organic anion-transporting polypeptide 2b1 (oatp2b1-slco2b1).	human organic anion-transporting polypeptide (oatp) 2b1 (oatp-b; slco2b1) is expressed in the apical membrane of the small intestine and the hepatocyte basolateral membrane and transports structurally diverse organic anions with a wide spectrum of ph sensitivities. this article describes highly ph-dependent oatp2b1-mediated antifolate transport and compares this property with that of sulfobromophthalein (bsp), a preferred oatp2b1 substrate. at ph 5.5 and low substrate concentrations (∼2.5 μm), o ...	2011	22021325
pulmonary compliance and lung volume varies with ecomorphology in anuran amphibians: implications for ventilatory-assisted lymph flux.	vertical movement of lymph from ventral regions to the dorsally located lymph hearts in anurans is accomplished by specialized skeletal muscles working in concert with lung ventilation. we hypothesize that more terrestrial species with greater lymph mobilization capacities and higher lymph flux rates will have larger lung volumes and higher pulmonary compliance than more semi-aquatic or aquatic species. we measured in situ mean and maximal compliance (δvolume/δpressure), distensibility (%δvolume ...	2011	21900475
influence of sugar ring conformation on the transportability of nucleosides by human nucleoside transporters.	the conformational preference of human nucleoside transporters (hnts) with respect to sugar ring was examined using conformationally fixed purine and pyrimidine nucleosides built on a bicyclo[3.1.0]hexane template. these fixed-conformation nucleosides, methanocarba-deoxyadenosine or methanocarba-deoxycytidine in north (c3'-endo, n-mcda and n-mcdc) or south (c2'-endo, s-mcda and s-mcdc) conformations, were used to study inhibition of equilibrative (hent1-4) and concentrative (hcnt1-3) nucleoside ...	2011	22052809
the genomic features that affect the lengths of 5' untranslated regions in multicellular eukaryotes.	the lengths of 5'utrs of multicellular eukaryotes have been suggested to be subject to stochastic changes, with upstream start codons (uaugs) as the major constraint to suppress 5'utr elongation. however, this stochastic model cannot fully explain the variations in 5'utr length. we hypothesize that the selection pressure on a combination of genomic features is also important for 5'utr evolution. the ignorance of these features may have limited the explanatory power of the stochastic model. furth ...	2011	22152105
the iron transporter ferroportin can also function as a manganese exporter.	the present study examined the hypothesis that the iron exporter ferroportin (fpn1/slc40a1) can also mediate cellular export of the essential trace element manganese, using xenopus laevis oocytes expressing human fpn1. when compared to oocytes expressing only the divalent metal transporter-1 (dmt1/nramp2), (54)mn accumulation was lower in oocytes also expressing fpn1. fpn1-expressing oocytes exported more (54)mn than control oocytes (26.6±0.6% versus 7.1±0.5%, respectively, over 4h at ph 7.4 whe ...	2011	22178646
single-cell electroporation in xenopus.	single-cell electroporation (sce) is a versatile technique for delivering electrically charged macromolecules including dna, rna, synthetic oligonucleotides, peptides, dyes, and drugs to individual cells within intact tissues. here, we describe methods for in vivo-targeted electroporation of single tectal neurons within the albino xenopus laevis tadpole. focal electroporation is achieved using a pipette electrode filled with a solution of the delivery molecules and with a tip diameter much small ...	2011	21880813
fgf signaling is required for lens regeneration in xenopus laevis.	in species of the frog genus xenopus, lens regeneration occurs through a process of transdifferentiation, in which cornea epithelial cells presumably undergo dedifferentiation and subsequently redifferentiate to form a new lens. experimental studies have shown that the retina provides the key signal required to trigger this process once the original lens is removed. a previous study showed that addition of an exogenous fibroblast growth factor (i.e., fgf1 protein) could initiate transdifferentia ...	2011	21876116
tissue-specific alternative splicing of tak1 is conserved in deuterostomes.	alternative splicing allows organisms to rapidly modulate protein functions to physiological changes and therefore represents a highly versatile adaptive process. we investigated the conservation of the evolutionary history of the "fox" family of rna-binding splicing factors (rbfox) as well as the conservation of regulated alternative splicing of the genes they control. we found that the rbfox proteins are conserved in all metazoans examined. in humans, fox proteins control muscle-specific alter ...	2011	21873631
functional impairment of rat taurine transporter by activation of nitrogen oxide through superoxide.	the objective of this study was to identify the nitrogen oxide form(s) involved in the functional impairment of the rat taurine transport system. taurine uptake activity in the rat renal brush border membrane vesicle (rbbmv) preparation or xenopus laevis oocytes that express the rat taurine transporter was compared after the pretreatment with nitrogen oxide donors from which nitric oxide (no) is released at different rates. the functional impairment was associated with a reduced v(max), but did ...	2011	22166889
host-defense peptides in skin secretions of african clawed frogs (xenopodinae, pipidae).	african clawed frogs of the xenopodinae (xenopus+silurana) constitute a well-defined system in which to study the evolutionary trajectory of duplicated genes and are a source of antimicrobial peptides with therapeutic potential. allopolyploidization events within the xenopodinae have given rise to tetraploid, octoploid, and dodecaploid species. the primary structures and distributions of host-defense peptides from the tetraploid frogs xenopus borealis, xenopusclivii, xenopuslaevis, xenopusmuelle ...	2011	22036891
developing laryngeal muscle of xenopus laevis as a model system; androgen-driven myogenesis controls fiber type transformation.	the developmental programs that contribute to myogenic stem cell proliferation and muscle fiber differentiation control fiber numbers and twitch type. here we describe the use of an experimental model system - androgen-regulated laryngeal muscle of juvenile clawed frogs, xenopus laevis - to examine the contribution of proliferation, by specific populations of myogenic stem cells, to expression of the larynx-specific myosin heavy chain isoform, lm. androgen treatment of juveniles (stage pm0) resu ...	2011	21954146
xenopus research: metamorphosed by genetics and genomics.	research using xenopus takes advantage of large, abundant eggs and readily manipulated embryos in addition to conserved cellular, developmental and genomic organization with mammals. research on xenopus has defined key principles of gene regulation and signal transduction, embryonic induction, morphogenesis and patterning as well as cell cycle regulation. genomic and genetic advances in this system, including the development of xenopus tropicalis as a genetically tractable complement to the wide ...	2011	21963197
cortical localization of maternal embryonic leucine zipper kinase (melk) implicated in cytokinesis in early xenopus embryos.	melk has been implicated in a large variety of functions. because its level is elevated in cancer tissues and it is involved in cell proliferation, melk is considered as a potential therapeutic target for cancers. in a recent, study we have shown that melk is involved in cytokinesis in early xenopus laevis embryos. melk dynamically accumulates at the cell cortex including a narrow band corresponding to the presumptive division furrow shortly before cytokinesis onset. melk co-localizes and intera ...	2011	21966578
the gastrocoel roof plate in embryos of different frogs.	the morphology of the gastrocoel roof plate and the presence of cilia in this structure were examined in embryos of four species of frogs. embryos of ceratophrys stolzmanni (ceratophryidae) and engystomops randi (leiuperidae) develop rapidly, provide comparison for the analysis of gastrocoel roof plate development in the slow-developing embryos of epipedobates machalilla (dendrobatidae) and gastrotheca riobambae (hemiphractidae). embryos of the analyzed frogs develop from eggs of different sizes ...	2011	22138030
skin impulse excitation of spinal sensory neurons in developing xenopus laevis (daudin) tadpoles.	responses to gentle touch in young xenopus tadpoles are mediated by spinal cord sensory rohon-beard neurons. tadpoles also respond to noxious stimuli that elicit 'skin impulses', which propagate between epithelial cells over the whole body surface, somehow entering the cns to generate a response. after hatching (~48 h post-fertilization), skin impulse signals enter the cns only via cranial nerves, but previous evidence suggested the possibility of direct entry to the spinal cord before this (~24 ...	2011	21957097
the rift valley is a major barrier to dispersal of african clawed frogs (xenopus) in ethiopia.	the ethiopian highlands - home to striking species diversity and endemism - are bisected by the rift valley, a zone of tectonic divergence. using molecular data we examined the evolutionary history of two co-distributed species of african clawed frog (xenopus clivii and x. largeni) that are endemic to this region. our field collections substantially extend the known distribution of x. largeni, a species formerly known from highlands southeast of the rift, but that also occurs to the northwest. i ...	2011	21933293
expression of wnt signaling components during xenopus pronephros development.	the formation of the vertebrate kidney is tightly regulated and relies on multiple evolutionarily conserved inductive events. these are present in the complex metanephric kidney of higher vertebrates, but also in the more primitive pronephric kidney functional in the larval stages of amphibians and fish. wnts have long been viewed as central in this process. canonical β-catenin-dependent wnt signaling establishes kidney progenitors and non-canonical β-catenin-independent wnt signaling participat ...	2011	22028899
possible roles of enac and cl(-) channel in wound closure in xenopus laevis embryos.	our previous report showed that rapid wound closure in xenopus laevis embryos was associated with a decrease in the extracellular concentration of either na(+) or cl(-) ions. in this study, we examined the wound closure in xenopus embryos when epithelial na(+) channel (enac), na(+)/k(+) atpase (na(+) pump) or cics (members of cl(-) channel) were blocked by each specific inhibitor. blockage of enac and cic restricted the rate of wound closure during the first 30 min pw and during the subsequent p ...	2011	21967216
enac channels in oocytes from xenopus laevis and their regulation by xshroom1 protein.	shroom is a family of related proteins linked to the actin cytoskeleton. xshroom1 is constitutively expressed in x. oocytes and is required for the expression of amiloride sensitive sodium channels (enac). oocytes were injected with α, β, and γ menac and xshroom1 sense or antisense oligonucleotides. we used voltage clamp techniques to study the amiloride-sensitive na(+) currents (ina((amil))). we observed a marked reduction in ina((amil)) in oocytes co-injected with xshroom1 antisense. oocytes e ...	2011	21865733
histology of plastic embedded amphibian embryos and larvae.	amphibians including the south african clawed frog xenopus laevis, its close relative xenopus tropicalis, and the mexican axolotl (ambystoma mexicanum) are important vertebrate models for cell biology, development, and regeneration. for the analysis of embryos and larva with altered gene expression in gain-of-function or loss-of-function studies histology is increasingly important. here, we discuss plastic or resin embedding of embryos as valuable alternatives to conventional paraffin embedding. ...	2011	22083609
expression and characterization of the bacterial mechanosensitive channel mscs in xenopus laevis oocytes.	we have successfully expressed and characterized mechanosensitive channel of small conductance (mscs) from escherichia coli in oocytes of the african clawed frog, xenopus laevis. mscs expressed in oocytes has the same single-channel conductance and voltage dependence as the channel in its native environment. two hallmarks of mscs activity, the presence of conducting substates at high potentials and reversible adaptation to a sustained stimulus, are also exhibited by oocyte-expressed mscs. in add ...	2011	22084416
the role of rice phenolics efflux transporter in solubilizing apoplasmic iron.	iron (fe) is an essential micronutrient for plants whose deficiency presents a major worldwide agricultural problem. moreover, fe is not easily available in neutral to alkaline soils, rendering plants deficient in fe despite its abundance. plants secrete phenolics, such as protocatechuic acid (pca) and caffeic acid (ca), to take up and utilize apoplasmic precipitated fe, but despite the rapid progress in understanding cellular and subcellular fe transport, the molecular mechanisms of phenolics s ...	2011	21921697
novel ncc mutants and functional analysis in a new cohort of patients with gitelman syndrome.	gitelman syndrome (gs) is an autosomal recessive disorder characterized by hypokalemic metabolic alkalosis in conjunction with significant hypomagnesemia and hypocalciuria. the gs phenotype is caused by mutations in the solute carrier family 12, member 3 (slc12a3) gene that encodes the thiazide-sensitive nacl cotransporter (ncc). we analyzed dna samples of 163 patients with a clinical suspicion of gs by direct sequencing of all 26 exons of the slc12a3 gene. in total, 114 different mutations were ...	2011	22009145
isolation and characterisation of a new antimicrobial peptide from the skin of xenopus laevis.	a new antimicrobial peptide (amp) named pgla-h has been isolated from the skin of the african clawed frog (xenopus laevis) using gel filtration and reverse-phase high-performance liquid chromatography (rp-hplc). its amino acid sequence was determined as kiakvalkal by edman degradation, with a molecular weight of 1053.727 da as analysed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (maldi-tof/tof-ms). no similar amp was found by blast search. purified pgla-h demo ...	2011	22014884
the influence of calcium ions on nickel modulation of nmda receptor currents.	n-methyl-d-aspartate (nmda) receptors (nrs) are glutamate-gated channels critical for the functioning of the nervous system. they are assembled from two types of subunits, the essential glun1 and at least one type of glun2 (a, b, c, d) subunit. nickel (ni) modulates the nr current in a way dependent on the glun2 subunit present. besides voltage-dependent and voltage-independent inhibition, in glun2b-containing channels ni enhances channel activity. we have recently identified several domains of ...	2011	22005730
dipolar versus octupolar triphenylamine-based fluorescent organic nanoparticles as brilliant one- and two-photon emitters for (bio)imaging.	two related triphenylamine-based dipolar and octupolar fluorophores are used to prepare aqueous suspensions of fluorescent organic nanoparticles (fons) via the reprecipitation method. the obtained spherical nanoparticles (30-40 nm in diameter) are fluorescent in aqueous solution (up to 15% fluorescence quantum yield) and exhibit extremely high one- and two-photon brightness, superior to those obtained for quantum dots. despite the two chromophores showing similar fluorescence in solution, the fl ...	2011	21972222
pentavalent arsenate transport by zebrafish phosphate transporter napi-iib1.	arsenate is a pentavalent form of arsenic that shares similar chemical properties to phosphate. it has been shown to be taken up by phosphate transporters in both eukaryotic and prokaryotic microbes such as yeast and escherichia coli. recently, the arsenate uptake in vertebrate cells was reported to be facilitated by mammalian type ii sodium/phosphate transporter with different affinities. as arsenate is the most common form of arsenic exposure in aquatic system, identifying the uptake pathway o ...	2011	21854209
Acquisition of glial cells missing 2 enhancers contributes to a diversity of ionocytes in zebrafish.	Glial cells missing 2 (gcm2) encoding a GCM-motif transcription factor is expressed in the parathyroid in amniotes. In contrast, gcm2 is expressed in pharyngeal pouches (a homologous site of the parathyroid), gills, and H(+)-ATPase-rich cells (HRCs), a subset of ionocytes on the skin surface of the teleost fish zebrafish. Ionocytes are specialized cells that are involved in osmotic homeostasis in aquatic vertebrates. Here, we showed that gcm2 is essential for the development of HRCs and Na(+)-Cl ...	2011	21858216
[Statistical study of rapid mechanodependent cell movements in deformed explants of African clawed frog Xenopus laevis embryonic tissues].	Computer analysis of artificially deformed (stretched or compressed) double explants (sandwiches) of the blastocoel roof (BRs) and suprablastoporal region (SBRs) of African clawed frog Xenopus laevis early gastrula has been performed using frames of time-lapse microfilming. During the first 14 min after cutting off, the velocities and displacement angles of several hundreds of cells relative to one another, as well as to fixed points and the extension axis, were measured in the control and defor ...	2011	22145303
beyond the frog: the evolution of homology models of human ikkβ.	nuclear factor κ b is implicated in tumor progression and chronic inflammatory diseases and is regulated by iκb kinase β (ikkβ). the crystal structure of ikkβ has been recently solved for xenopus laevis. homology models of human ikkβ have been developed prior to and after the crystal structure was solved. here, we compare four models of human ikkβ and evaluate their performance in both broad and focused library docking studies.	2011	21911292
AtHKT1;1 mediates nernstian sodium channel transport properties in Arabidopsis root stelar cells.	The Arabidopsis AtHKT1;1 protein was identified as a sodium (Na?) transporter by heterologous expression in Xenopus laevis oocytes and Saccharomyces cerevisiae. However, direct comparative in vivo electrophysiological analyses of a plant HKT transporter in wild-type and hkt loss-of-function mutants has not yet been reported and it has been recently argued that heterologous expression systems may alter properties of plant transporters, including HKT transporters. In this report, we analyze severa ...	2011	21931830
altered development of xenopus embryos in a hypogeomagnetic field.	the hypogeomagnetic field (hgmf; magnetic fields <200 nt) is one of the fundamental environmental factors of space. however, the effect of hgmf exposure on living systems remains unclear. in this article, we examine the biological effects of hgmf on the embryonic development of xenopus laevis (african clawed frog). a decrease in horizontal third cleavage furrows and abnormal morphogenesis were observed in xenopus embryos growing in the hgmf. hgmf exposure at the two-cell stage, but no later than ...	2011	21853450
kazrin, and its binding partners arvcf- and delta-catenin, are required for xenopus laevis craniofacial development.	the novel adaptor protein kazrin associates with multifunctional entities including p120-subfamily members (arvcf-, delta-, and p0071-catenin). critical contributions of kazrin to development or homeostasis are indicated with respect to ectoderm formation, integrity and keratinocyte differentiation, whereas its presence in varied tissues suggests broader roles. we find that kazrin is maternally loaded, is expressed across development and becomes enriched in the forming head. kazrin's potential c ...	2011	22028074
interaction and transport of kynurenic acid via human organic anion transporters hoat1 and hoat3.	kynurenic acid, a catabolite of tryptophan, is suggested to be involved in schizophrenia, and is known to be a uremic toxin, although there is little information about the mechanism of its disposition. in this study, we performed uptake experiment using xenopus laevis oocyte expression system to examine the transport of kynurenic acid by human organic anion transporters hoat1 (slc22a6) and hoat3 (slc22a8), which mediate the transport of organic anions in the brain and kidney. the uptake of p-ami ...	2011	22108572
exposure to external environment of low ion concentrations is the trigger for rapid wound closure in xenopus laevis embryos.	wounds in xenopus laevis embryos close rapidly, as previously described. in this study, we examined the dependence on extracellular na(+) and/or cl(-) ion concentrations of the closure of wounds in xenopus embryos inflicted by thermal injury. wound closure did not occur in normal amphibian medium (100% nam), while wound areas remarkably decreased either in 10-50% nam or in 100% nam lacking na(+) or cl(-). similarly, wound areas did not change in a set of na(+) and cl(-) ion concentrations equiva ...	2011	21882951
deubiquitylating enzyme usp2 counteracts nedd4-2-mediated downregulation of kcnq1 potassium channels.	background: kcnq1 (kv7.1), together with its kcne β subunits, plays a pivotal role both in the repolarization of cardiac tissue and in water and salt transport across epithelial membranes. nedd4/nedd4-like (neuronal precursor cell-expressed developmentally downregulated 4) ubiquitin-protein ligases interact with the kcnq1 potassium channel through a py motif located in the c terminus of kcnq1. this interaction induces ubiquitylation of kcnq1, resulting in a reduced surface density of the channel ...	2011	22024150
the odds of duplicate gene persistence after polyploidization.	abstract:	2011	22151890
peptides from the pituitary gland and cortex stimulate differentiation of polypotent embryonic tissue.	we studied the effects of synthetic peptides from the pituitary gland and brain cortex on differentiation of polypotent ectodermal tissue of the early gastrula of xenopus laevis. it was shown that the pituitary gland peptide stimulates differentiation of polypotent tissue into epidermis and nerve tissue, while brain cortex peptide induces the development of mesenchyma and epidermis. differentiation of polypotent tissue under the effect of the peptide is a mechanism of their geroprotective effect ...	2011	22448383
Targeting of mouse guanylate cyclase 1 (Gucy2e) to Xenopus laevis rod outer segments.	Photoreceptor guanylate cyclase (GC1) is a transmembrane protein and responsible for synthesis of cGMP, the secondary messenger of phototransduction. It consists of an extracellular domain, a single transmembrane domain, and an intracellular domain. It is unknown how GC1 targets to the outer segments where it resides. To identify a putative GC1 targeting signal, we generated a series of peripheral membrane and transmembrane constructs encoding extracellular and intracellular mouse GC1 fragments ...	2011	21945483
melatonin receptors are anatomically organized to modulate transmission specifically to cone pathways in the retina of xenopus laevis.	melatonin receptors have been identified in several retinal cell types, including photoreceptors, horizontal cells, amacrine cells, and ganglion cells. recent reports suggest that melatonin potentiates signaling from rods to inner retinal neurons. however, the organization of the melatonin receptors mediating this action in the outer plexiform layer (opl) is not clear. to assess melatonin receptor localization in the opl, double-label confocal immunohistochemistry for mel1a or mel1b melatonin re ...	2011	22020534
aquaporin 4 is a ubiquitously expressed isoform in the dogfish (squalus acanthias) shark.	the dogfish ortholog of aquaporin 4 (aqp4) was amplified from cdna using degenerate pcr followed by cloning and sequencing. the complete coding region was then obtained using 5' and 3' race techniques. alignment of the sequence with aqp4 amino acid sequences from other species showed that dogfish aqp4 has high levels (up to 65.3%) of homology with higher vertebrate sequences but lower levels of homology to agnathan (38.2%) or teleost (57.5%) fish sequences. northern blotting indicated that the d ...	2011	22291652
discovery, characterization, and structure-activity relationships of an inhibitor of inward rectifier potassium (kir) channels with preference for kir2.3, kir3.x, and kir7.1.	the inward rectifier family of potassium (kir) channels is comprised of at least 16 family members exhibiting broad and often overlapping cellular, tissue, or organ distributions. the discovery of disease-causing mutations in humans and experiments on knockout mice has underscored the importance of kir channels in physiology and in some cases raised questions about their potential as drug targets. however, the paucity of potent and selective small-molecule modulators targeting specific family me ...	2011	22275899
Comparative homology modeling of pyruvate dehydrogenase kinase isozymes from Xenopus tropicalis reveals structural basis for their subfunctionalization.	Structural-functional divergence is responsible for the preservation of highly homologous genes. Protein functions affected by mutagenesis in divergent sequences require investigation on an individual basis. In the present study, comparative homology modeling and predictive bioinformatics analysis were used to reveal for the first time the subfunctionalization of two pyruvate dehydrogenase kinase (PDK) isozymes in the western clawed frog Xenopus tropicalis. Three-dimensional structures of the tw ...	2011	22069030
serum agr2 as an early diagnostic and postoperative prognostic biomarker of human lung adenocarcinoma.	in the present study, the human orthologue of the secreted xenopus laevis anterior gradient 2 (agr2) protein was evaluated as a potential serum biomarker of lung adenocarcinoma. agr2 protein levels were preoperatively measured in the serum of 111 primary lung adenocarcinoma patients and in 46 non-cancer controls with subsequent calculation of sensitivity and specificity in comparison with serum cea levels. correlations with clinicopathological variables were also assessed and survival analyses w ...	2011	22430137
Ecological immunogenetics of life-history traits in a model amphibian.	Major histocompatibility complex (MHC) genes determine immune repertoires and social preferences of vertebrates. Immunological regulation of microbial assemblages associated with individuals influences their sociality, and should also affect their life-history traits. We exposed Xenopus laevis tadpoles to water conditioned by adult conspecifics. Then, we analysed tadpole growth, development and survivorship as a function of MHC class I and class II peptide-binding region amino acid sequence simi ...	2011	22114322
kcnq1 subdomains involved in kcne modulation revealed by an invertebrate kcnq1 orthologue.	kcnq1 channels are voltage-gated potassium channels that are widely expressed in various non-neuronal tissues, such as the heart, pancreas, and intestine. kcne proteins are known as the auxiliary subunits for kcnq1 channels. the effects and functions of the different kcne proteins on kcnq1 modulation are various; the kcnq1-kcne1 ion channel complex produces a slowly activating potassium channel that is crucial for heartbeat regulation, while the kcne3 protein makes kcnq1 channels constitutively ...	2011	22042987
the rna-binding protein xp54nrb isolated from a ca(2+)-dependent screen is expressed in neural structures during xenopus laevis development.	in amphibian embryos, calcium (ca(2+)) signalling is a necessary and sufficient event to induce neural fate. transient elevations of [ca(2+)]i are recorded in neural tissue precursor cells in whole embryos during gastrulation. using a subtractive cdna library between control ectoderm (animal caps) and ectoderm induced toward a neural fate by ca(2+) release, we have isolated several ca(2+)-induced target genes. among the isolated genes, xp54nrb encodes a protein which exhibits the rrm domains cha ...	2011	22252489
Integument structure and function in juvenile Xenopus laevis with disrupted thyroid balance.	The skin is the largest organ in the body and is a barrier between the internal and external environment. The present study evaluates how PTU, a goitrogen, that is used to treat hyperthyroidism affects the structure and electrical properties of the frog (Xenopus laevis) skin. The results are considered in the context of the two-membrane model established in the seminal work of Ussing and collegues in the 1940s and 1950s. In vitro experiments with skin from Xenopus adults revealed that PTU can ac ...	2011	21963960
Filaments assembly of ectopically expressed Caenorhabditis elegans lamin within Xenopus oocytes.	Lamins are the major components of the nuclear lamina, a filamentous layer underlying the inner nuclear membrane and attached to the peripheral chromatin. Lamins are required for maintaining nuclear shape and are involved in most nuclear activities. Here, we studied the 3D organization of the nuclear lamina formed upon the expression of Caenorhabditis elegans lamin (Ce-lamin) within the nucleus of a Xenopus laevis oocyte. We show that Ce-lamin forms an intricate 3D meshwork of 5-6nm lamin protof ...	2011	22085746
mir-124 acts through corest to control onset of sema3a sensitivity in navigating retinal growth cones.	during axon pathfinding, growth cones commonly show changes in sensitivity to guidance cues that follow a cell-intrinsic timetable. the cellular timer mechanisms that regulate such changes are, however, poorly understood. here we have investigated micrornas (mirnas) in the timing control of sensitivity to the semaphorin sema3a in xenopus laevis retinal ganglion cell (rgc) growth cones. a developmental profiling screen identified mir-124 as a candidate timer. loss of mir-124 delayed the onset of ...	2011	22138647
investigation of the molecular mechanism of the α7 nicotinic acetylcholine receptor positive allosteric modulator pnu-120596 provides evidence for two distinct desensitized states.	although α7 nicotinic acetylcholine receptors are considered potentially important therapeutic targets, the development of selective agonists has been stymied by the α7 receptor's intrinsically low probability of opening (p(open)) and the concern that an agonist-based therapeutic approach would disrupt endogenous cholinergic function. development of α7 positive allosteric modulators (pams) holds promise of avoiding both issues. n-(5-chloro-2,4-dimethoxyphenyl)-n'-(5-methyl-3-isoxazolyl)-urea (pn ...	2011	21885620
Cloning and expression analysis of interferon-?-inducible-lysosomal thiol reductase gene in South African clawed frog (Xenopus laevis).	In this study, an interferon-?-inducible-lysosomal thiol reductase (GILT) homologue has been cloned and identified from South African clawed frog Xenopus laevis (designated XlGILT). The open reading frame (ORF) of XlGILT consists of 771 bases encoding a protein of 256 amino acids with an estimated molecular mass of 28.76kDa and a theoretical isoelectric point of 5.12. The N-terminus of the XlGILT was found to have a putative signal peptide with a cleavage site amino acid position at 15-16. SMART ...	2011	21951863
Modulation of Thyroid Hormone-Dependent Gene Expression in Xenopus laevis by INhibitor of Growth (ING) Proteins.	INhibitor of Growth (ING) proteins belong to a large family of plant homeodomain finger-containing proteins important in epigenetic regulation and carcinogenesis. We have previously shown that ING1 and ING2 expression is regulated by thyroid hormone (TH) during metamorphosis of the Xenopus laevis tadpole. The present study investigates the possibility that ING proteins modulate TH action.	2011	22163049
genome-wide analysis of gene expression during xenopus tropicalis tadpole tail regeneration.	the molecular mechanisms governing vertebrate appendage regeneration remain poorly understood. uncovering these mechanisms may lead to novel therapies aimed at alleviating human disfigurement and visible loss of function following injury. here, we explore tadpole tail regeneration in xenopus tropicalis, a diploid frog with a sequenced genome.	2011	22085734
host-defense peptides from skin secretions of the tetraploid frogs xenopus petersii and xenopus pygmaeus, and the octoploid frog xenopus lenduensis (pipidae).	peptidomic analysis of norepinephrine-stimulated skin secretions led to the identification of host-defense peptides belonging to the magainin, peptide glycine-leucine-amide (pgla), and caerulein precursor fragment (cpf) families from the tetraploid frogs, xenopus petersii (peters' clawed frog) and xenopus pygmaeus (bouchia clawed frog), and the octoploid frog xenopus lenduensis (lendu plateau clawed frog). xenopsin-precursor fragment (xpf) peptides were not detected. the primary structures of th ...	2011	22123629
Strong activation of ether-à-go-go-related gene 1 K+ channel isoforms by NS1643 in human embryonic kidney 293 and Chinese hamster ovary cells.	Two different mechanisms leading to increased current have been described for the small-molecule human ether-à-go-go-related gene (herg) activator NS1643 [1,3-bis-(2-hydroxy-5-trifluoromethylphenyl)-urea]. On herg1a channels expressed in Xenopus laevis oocytes, it mainly acts via attenuation of inactivation and for rat (r) erg1b channels expressed in human embryonic kidney (HEK)-293 cells, it strongly shifts the activation curve to the left. We now investigated the NS1643 effects on erg1b channe ...	2011	21856740
mouse sperm exhibit chemotaxis to allurin, a truncated member of the cysteine-rich secretory protein family.	allurin, a 21 kda protein isolated from egg jelly of the frog xenopus laevis, has previously been demonstrated to attract frog sperm in two-chamber and microscopic assays. cdna cloning and sequencing has shown that allurin is a truncated member of the cysteine-rich secretory protein (crisp) family, whose members include mammalian sperm-binding proteins that have been postulated to play roles in spermatogenesis, sperm capacitation and sperm-egg binding in mammals. here, we show that allurin is a ...	2011	22008793
Toward an unbiased evolutionary platform for unraveling Xenopus developmental gene networks.	The availability of both the Xenopus tropicalis genome and the soon to be released Xenopus laevis genome provides a solid foundation for Xenopus developmental biologists. The Xenopus community has presently amassed expression data for ~2,300 genes in the form of published images collected in the Xenbase, the principal Xenopus research database. A few of these genes have been examined in both X. tropicalis and X. laevis and the cross-species comparison has been proven invaluable for studying gene ...	2011	21956895
Unfertilized frog eggs die by apoptosis following meiotic exit.	ABSTRACT: BACKGROUND: A characteristic feature of frog reproduction is external fertilization accomplished outside the female's body. Mature fertilization-competent frog eggs are arrested at the meiotic metaphase II with high activity of the key meiotic regulators, maturation promoting factor (MPF) and cytostatic factor (CSF), awaiting fertilization. If the eggs are not fertilized within several hours of ovulation, they deteriorate and ultimately die by as yet unknown mechanism. RESULTS: Here, ...	2011	22195698
[Molecular cloning and functional characterization of a novel gene encoding human prostaglandin carrier, hPrC].	In the present study, we isolated and determined the pharmacological characteristics of a novel gene encoding the human prostaglandin carrier (hPrC). The isolated cDNA consisted of 1431 base pairs that encoded a 477-amino acid protein, and we found that isolated hPrC does not belong to any drug transporter families. RT-PCR analysis revealed that the hPrC mRNA is expressed in various human tissues ubiquitously. When expressed in Xenopus laevis oocytes, hPrC mediated the transport of [(3)H]prostag ...	2011	21963977
transient expression of ngn3 in xenopus endoderm promotes early and ectopic development of pancreatic beta and delta cells.	promoting ectopic development of pancreatic beta cells from other cell types is one of the strategies being pursued for the treatment of diabetes. to achieve this, a detailed outline of the molecular lineage that operates in pancreatic progenitor cells to generate beta cells over other endocrine cell types is necessary. here, we demonstrate that early transient expression of the endocrine progenitor bhlh protein neurogenin 3 (ngn3) favors the promotion of pancreatic beta and delta cell fates ove ...	2011	22121111
protein arginine methyltransferase prmt5-mep50 methylates histones h2a and h4 and the histone chaperone nucleoplasmin in xenopus laevis eggs.	histone proteins carry information contained in post-translational modifications. eukaryotic cells utilize this histone code to regulate the usage of the underlying dna. in the maturing oocytes and eggs of the frog xenopus laevis, histones are synthesized in bulk in preparation for deposition during the rapid early developmental cell cycles. during this key developmental time frame, embryonic pluripotent chromatin is established. in the egg, non-chromatin-bound histones are complexed with storag ...	2011	22009756
Identification and functional characterization of an ovarian aquaporin from the cockroach Blattella germanica L. (Dictyoptera, Blattellidae).	Aquaporins (AQPs) are membrane proteins that form water channels, allowing rapid movement of water across cell membranes. AQPs have been reported in species of all life kingdoms and in almost all tissues, but little is known about them in insects. Our purpose was to explore the occurrence of AQPs in the ovary of the phylogenetically basal insect Blattella germanica (L.) and to study their possible role in fluid homeostasis during oogenesis. We isolated an ovarian AQP from B. germanica (BgAQP) th ...	2011	21993792
Germ plasm in Eleutherodactylus coqui, a direct developing frog with large eggs.	ABSTRACT:	2011	21978790
Retinoic acid is a key regulatory switch determining the difference between lung and thyroid fates in Xenopus laevis.	ABSTRACT: BACKGROUND: The lung and thyroid are derived from the anterior endoderm. Retinoic acid and Fgf signalling are known to be essential for development of the lung in mouse but little is known on how the lung and thyroid are specified in Xenopus. RESULTS: If either retinoic acid or Fgf signalling is inhibited, there is no differentiation of the lung as assayed by expression of sftpb. There is no change in expression of thyroid gland markers when can differentiate when either retinoic ...	2011	22185339
ion currents induced by atp and angiotensin ii in cultured follicular cells of xenopus laevis.	xenopus laevis oocytes are commonly used to study the biophysical and pharmacological properties of foreign ion channels and receptors, but little is known about those endogenously expressed in their enveloping layer of follicular cells (fcs). whole-cell recordings and the perforated patch-clamp technique in cultured fcs held at -60 mv revealed that atp (20-250 μm) generates inward currents of 465 ± 93 pa (mean ± standard error) in ~60% of the fcs studied, whereas outward currents of 317 ± 100 p ...	2011	22083304
23 khz mems based swept source for optical coherence tomography imaging.	the transition from benchtop to clinical system often requires the medical technology to be robust, portable and accurate. this poses a challenge to current swept source optical coherence tomography imaging systems, as the bulk of the systems footprint is due to laser components. with the recent advancement of micromachining technology, we demonstrate the characterization of a microelectromechanical system (mems) swept source laser for optical coherence tomography imaging (oct). this laser utili ...	2011	22255739
The effect of anions on the human P2X7 receptor.	P2X7 receptors (P2X7Rs) are nonselective cation channels that are opened by the binding of extracellular ATP and are involved in the modulation of epithelial secretion, inflammation and nociception. Here, we investigated the effect of extracellular anions on channel gating and permeation of human P2X7Rs (hP2X7Rs) expressed in Xenopus laevis oocytes. Two-microelectrode voltage-clamp recordings showed that ATP-induced hP2X7R-mediated currents increased when extracellular chloride was substituted b ...	2011	21872569
Origin and segregation of cranial placodes in Xenopus laevis.	Cranial placodes are local thickenings of the vertebrate head ectoderm that contribute to the paired sense organs (olfactory epithelium, lens, inner ear, lateral line), cranial ganglia and the adenohypophysis. Here we use tissue grafting and dye injections to generated fate maps of the dorsal cranial part of the non-neural ectoderm for Xenopus embryos between neural plate and early tailbud stages. We show that all placodes arise from a crescent-shaped area located around the anterior neural plat ...	2011	21989028
D184E mutation in aquaporin-4 gene impairs water permeability and links to deafness.	Aquaporins (AQPs) play a physiological role in several organs and tissues, and their alteration is associated with disorders of water regulation. The identification of molecular interactions, which are crucial in determining the rate of water flux through the channel, is of pivotal role for the discovery of molecules able to target those interactions and therefore to be used for pathologies ascribable to an altered AQP-dependent water balance. In the present study, a mutational screening of huma ...	2011	21952128
improved knockout methodology reveals that frog virus 3 mutants lacking either the 18k immediate-early gene or the truncated vif-2alpha gene are defective for replication and growth in vivo.	to better assess the roles of frog virus 3 (fv3; genus ranavirus, family iridoviridae) genes in virulence and immune evasion, we have developed a reliable and efficient method to systematically knock out (ko) putative virulence genes by site-specific integration into the fv3 genome. our approach utilizes a dual selection marker consisting of the puromycin resistance gene fused in frame with the enhanced green fluorescent protein (egfp) reporter (puro-egfp cassette) under the control of the fv3 i ...	2011	21865381
INOH: ontology-based highly structured database of signal transduction pathways.	The Integrating Network Objects with Hierarchies (INOH) database is a highly structured, manually curated database of signal transduction pathways including Mammalia, Xenopus laevis, Drosophila melanogaster, Caenorhabditis elegans and canonical. Since most pathway knowledge resides in scientific articles, the database focuses on curating and encoding textual knowledge into a machine-processable form. We use a hierarchical pathway representation model with a compound graph, and every pathway comp ...	2011	22120663