Autoradiographic imaging of phosphoinositide turnover in the brain

International Nuclear Information System (INIS)

Hwang, P.M.; Bredt, D.S.; Snyder, S.H.

1990-01-01

With [ 3 H]cytidine as a precursor, phosphoinositide turnover can be localized in brain slices by selective autoradiography of the product [ 3 H]cytidine diphosphate diacylglycerol, which is membrane-bound. In the cerebellum, glutamatergic stimulation elicits an increase of phosphoinositide turnover only in Purkinje cells and the molecular layer. In the hippocampus, both glutamatergic and muscarinic cholinergic stimulation increase phosphoinositide turnover, but with distinct localizations. Cholinergic stimulation affects CA1, CA3, CA4, and subiculum, whereas glutamatergic effects are restricted to the subiculum and CA3. Imaging phosphoinositide turnover in brain slices, which are amenable to electrophysiologic studies, will permit a dynamic localized analysis of regulation of this second messenger in response to synaptic stimulation of specific neuronal pathways

Expression of the voltage-sensing phosphatase gene in the chick embryonic tissues and in the adult cerebellum.

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Yamaguchi, Shinji; Aoki, Naoya; Kitajima, Takaaki; Okamura, Yasushi; Homma, Koichi J

2014-10-01

Voltage-sensing phosphatase (VSP) consists of a transmembrane voltage sensor domain (VSD) and the cytoplasmic domain with phosphoinositide-phosphatase activities. It operates as the voltage sensor and directly translates membrane potential into phosphoinositide turnover by coupling VSD to the cytoplasmic domain. VSPs are evolutionarily conserved from marine invertebrate up to humans. Recently, we demonstrated that ectopic expression of the chick ortholog of VSP, Gg-VSP, in a fibroblast cell line caused characteristic cell process outgrowths. Co-expression of chick PTEN suppressed such morphological change, suggesting that VSP regulates cell shape by increasing PI(3,4)P2. However, the in vivo function of Gg-VSP remains unclear. Here, we showed that in chick embryos Gg-VSP is expressed in the stomach, mesonephros, pharyngeal arch, limb bud, somites, floor plate of neural tube, and notochord. In addition, both Gg-VSP transcripts and the protein were found in the cerebellar Purkinje neurons. These findings provide an insight into the physiological functions of VSP.

Voltage sensitive phosphatases: emerging kinship to protein tyrosine phosphatases from structure-function research

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Kirstin eHobiger

2015-02-01

Full Text Available The transmembrane protein Ci-VSP from the ascidian Ciona intestinalis was described as first member of a fascinating family of enzymes, the voltage sensitive phosphatases (VSPs. Ci-VSP and its voltage-activated homologs from other species are stimulated by positive membrane potentials and dephosphorylate the head groups of negatively charged phosphoinositide phosphates (PIPs. In doing so, VSPs act as control centers at the cytosolic membrane surface, because they intervene in signaling cascades that are mediated by PIP lipids. The characteristic motif CX5RT/S in the active site classifies VSPs as members of the huge family of cysteine-based protein tyrosine phosphatases (PTPs. Although PTPs have already been well characterized regarding both, structure and function, their relationship to VSPs has drawn only limited attention so far. Therefore, the intention of this review is to give a short overview about the extensive knowledge about PTPs in relation to the facts known about VSPs. Here, we concentrate on the structural features of the catalytic domain which are similar between both classes of phosphatases and their consequences for the enzymatic function. By discussing results obtained from crystal structures, molecular dynamics simulations, and mutagenesis studies, a possible mechanism for the catalytic cycle of VSPs is presented based on that one proposed for PTPs. In this way, we want to link the knowledge about the catalytic activity of VSPs and PTPs.

The emerging role of phosphoinositide clustering in intracellular trafficking and signal transduction [version 1; referees: 4 approved

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Laura Picas

2016-03-01

Full Text Available Phosphoinositides are master regulators of multiple cellular processes: from vesicular trafficking to signaling, cytoskeleton dynamics, and cell growth. They are synthesized by the spatiotemporal regulated activity of phosphoinositide-metabolizing enzymes. The recent observation that some protein modules are able to cluster phosphoinositides suggests that alternative or complementary mechanisms might operate to stabilize the different phosphoinositide pools within cellular compartments. Herein, we discuss the different known and potential molecular players that are prone to engage phosphoinositide clustering and elaborate on how such a mechanism might take part in the regulation of intracellular trafficking and signal transduction.

Role of Ocrl1 and Inpp5E in primary cilia assembly and maintenance: a phosphatidylinositol phosphatase relay system?

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Madhivanan K

2016-02-01

Full Text Available Kayalvizhi Madhivanan,* Swetha Ramadesikan,* R Claudio Aguilar Department of Biological Sciences, Purdue University, West Lafayette, IN, USA *These authors contributed equally to this work Abstract: The primary cilium (PC is a plasma membrane-derived structure of great importance for cell and organismal physiology. Indeed, abnormalities in assembly or function of the PC trigger the onset of a group of genetic diseases collectively known as ciliopathies. In recent years, it has become evident that the integrity and function of the PC depends substantially on signaling elements such as phosphoinositides (PI and their regulators. Because phospholipids such as PI(4,5P2 constitute recruitment platforms for cytoskeleton, signaling, and trafficking machinery, control over their levels is critical for PC function. Although information about phosphoinositol phosphate (PIP kinases in the PC is scarce, a growing body of evidence supports a role for PIP phosphatases in cilia assembly/maintenance. Indeed, deficiencies in two 5′ PIP phosphatases, Inpp5E and Ocrl1, are clearly linked to ciliopathies like Joubert/MORM syndromes, or ciliopathy-associated diseases like Lowe syndrome. Here, we review the unique roles of these proteins and their specific site of action for ensuring ciliary integrity. Further, we discuss the possibility that a phosphatase relay system able to pass PI control from a preciliary to an intraciliary compartment is in place to ensure PC integrity/function. Keywords: primary cilia, Ocrl1, Inpp5E, Pip2, Pip3

Myosin-1C uses a novel phosphoinositide-dependent pathway for nuclear localization.

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Nevzorov, Ilja; Sidorenko, Ekaterina; Wang, Weihuan; Zhao, Hongxia; Vartiainen, Maria K

2018-02-01

Accurate control of macromolecule transport between nucleus and cytoplasm underlines several essential biological processes, including gene expression. According to the canonical model, nuclear import of soluble proteins is based on nuclear localization signals and transport factors. We challenge this view by showing that nuclear localization of the actin-dependent motor protein Myosin-1C (Myo1C) resembles the diffusion-retention mechanism utilized by inner nuclear membrane proteins. We show that Myo1C constantly shuttles in and out of the nucleus and that its nuclear localization does not require soluble factors, but is dependent on phosphoinositide binding. Nuclear import of Myo1C is preceded by its interaction with the endoplasmic reticulum, and phosphoinositide binding is specifically required for nuclear import, but not nuclear retention, of Myo1C. Our results therefore demonstrate, for the first time, that membrane association and binding to nuclear partners is sufficient to drive nuclear localization of also soluble proteins, opening new perspectives to evolution of cellular protein sorting mechanisms. © 2018 The Authors. Published under the terms of the CC BY NC ND 4.0 license.

FIG4 regulates lysosome membrane homeostasis independent of phosphatase function

OpenAIRE

Bharadwaj, Rajnish; Cunningham, Kathleen M.; Zhang, Ke; Lloyd, Thomas E.

2015-01-01

FIG4 is a phosphoinositide phosphatase that is mutated in several diseases including Charcot-Marie-Tooth Disease 4J (CMT4J) and Yunis-Varon syndrome (YVS). To investigate the mechanism of disease pathogenesis, we generated Drosophila models of FIG4-related diseases. Fig4 null mutant animals are viable but exhibit marked enlargement of the lysosomal compartment in muscle cells and neurons, accompanied by an age-related decline in flight ability. Transgenic animals expressing Drosophila Fig4 mi...

Phosphoinositides: Key modulators of energy metabolism☆

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Bridges, Dave; Saltiel, Alan R.

2014-01-01

Phosphoinositides are key players in many trafficking and signaling pathways. Recent advances regarding the synthesis, location and functions of these lipids have dramatically improved our understanding of how and when these lipids are generated and what their roles are in animal physiology. In particular, phosphoinositides play a central role in insulin signaling, and manipulation of PtdIns(3,4,5)P3 levels in particular, may be an important potential therapeutic target for the alleviation of insulin resistance associated with obesity and the metabolic syndrome. In this article we review the metabolism, regulation and functional roles of phosphoinositides in insulin signaling and the regulation of energy metabolism. This article is part of a Special Issue entitled Phosphoinositides. PMID:25463477

Effects of thyroxine and 1-methyl, 2-mercaptoimidazol on phosphoinositides synthesis in rat liver

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Krasilnikova Oksana A

2004-12-01

Full Text Available Abstract Background Phosphoinositides mediate one of the intracellular signal transduction pathways and produce a class of second messengers that are involved in the action of hormones and neurotransmitters on target cells. Thyroid hormones are well known regulators of lipid metabolism and modulators of signal transduction in cells. However, little is known about phosphoinositides cycle regulation by thyroid hormones. The present paper deals with phosphoinositides synthesis de novo and acylation in liver at different thyroid status of rats. Results The experiments were performed in either the rat liver or hepatocytes of 90- and 720-day-old rats. Myo-[3H]inositol, [14C]CH3COONa, [14C]oleic and [3H]arachidonic acids were used to investigate the phosphatidylinositol (PtdIns, phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate (PtdInsP2 synthesis. 1-methyl, 2-mercaptoimidazol-induced hypothyroidism was associated with the decrease of myo-[3H]inositol and [3H]arachidonic acids incorporation into liver phosphoinositides and total phospholipids, respectively. The thyroxine (L-T4 injection to hypothyroid animals increased the hormones contents in blood serum and PtdInsP2 synthesis de novo as well as [3H]arachidonic acids incorporation into the PtdIns and PtdInsP2. Under the hormone action, the [14C]oleic acid incorporation into PtdIns reduced in the liver of hypothyroid animals. A single injection of L-T4 to the euthyroid [14C]CH3COONa-pre-treated animals or addition of the hormone to a culture medium of hepatocytes was accompanied by the rapid prominent increase in the levels of the newly synthesized PtdIns and PtdInsP2 and in the mass of phosphatidic acid in the liver or the cells. Conclusions The data obtained have demonstrated that thyroid hormones are of vital importance in the regulation of arachidonate-containing phosphoinositides metabolism in the liver. The drug-induced malfunction of thyroid gland noticeably changed the

Overexpression of BrSAC1 encoding a phosphoinositide ...

African Journals Online (AJOL)

2013-04-10

Apr 10, 2013 ... Chinese cabbage (Brassica rapa L) improved tolerance to cold ... 2Institute of Genetic Engineering, Hankyong National University, Ansung 456-749, Korea. .... First-strand cDNA was generated using SuperscriptTM III reverse.

Microvillus-Specific Protein Tyrosine Phosphatase SAP-1 Plays a Role in Regulating the Intestinal Paracellular Transport of Macromolecules.

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Mori, Shingo; Kamei, Noriyasu; Murata, Yoji; Takayama, Kozo; Matozaki, Takashi; Takeda-Morishita, Mariko

2017-09-01

The stomach cancer-associated protein tyrosine phosphatase 1 (SAP-1) is a receptor-type protein tyrosine phosphatase that is specifically expressed on the apical membrane of the intestinal epithelium. SAP-1 is known to maintain the balance of phosphorylation of proteins together with protein kinases; however, its biological function and impact on pharmacokinetics in the intestine remain unclear. The present study, therefore, aimed at clarifying the relationship between SAP-1 and the intestinal absorption behaviors of typical transporter substrates and macromolecules. The endogenous levels of glucose and total cholesterol in the blood were similar between wild-type and SAP-1-deficient mice (Sap1 -/- ), suggesting no contribution of SAP-1 to biogenic influx. Moreover, in vitro transport study with everted ileal sacs demonstrated that there was no difference in the absorption of breast cancer resistance protein, P-glycoprotein, and peptide transporter substrates between both mice. However, absorptive clearance of macromolecular model dextrans (FD-4 and FD-10) in Sap1 -/- mice was significantly higher than that in wild-type mice, and this was confirmed by the trend of increased FD-4 absorption from colonic loops of Sap1 -/- mice. Therefore, the results of this study suggest the partial contribution of SAP-1 to the regulated transport of hydrophilic macromolecules through paracellular tight junctions. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Zinc-ion-dependent acid phosphatase exhibits magnesium-ion-dependent myo-inositol-1-phosphatase activity.

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Fujimoto, S; Okano, I; Tanaka, Y; Sumida, Y; Tsuda, J; Kawakami, N; Shimohama, S

1996-06-01

We have purified bovine brain Zn(2+)-dependent acid phosphatase (Zn(2+)-APase), which requires Zn2+ ions to hydrolyze the substrate p-nitrophenyl phosphate (pNPP) in an acidic environment. The substrate specificity and metal requirement of Zn(2+)-APase at a physiological pH was also studied. The enzyme exhibited hydrolytic activity on myo-inositol-1- and -2-monophosphates, 2'-adenosine monophosphate, 2'-guanosine monophosphate, and the alpha- and beta-glycerophosphates, glucose-1-phosphate, and fructose-6-phosphate in 50 mM Tris-HCl buffer (pH 7.4) in the presence of Mg2+ ions, but not on pNPP and phosphotyrosine. Zn2+, Mn2+ and Co2+ ions were less effective for activation. Among the above substrates, myo-inositol-1-phosphate was the most susceptible to hydrolysis by the enzyme in the presence of 3 mM Mg2+ ions. The enzyme exhibited an optimum pH at around 8 for myo-inositol-1-phosphate in the presence of 3 mM Mg2+ ions. The Mg(2+)-dependent myo-inositol-1-phosphatase activity of the enzyme was significantly inhibited by Li+ ions. The Zn(2+)-dependent p-nitrophenyl phosphatase activity and Mg(2+)-dependent myo-inositol-1-phosphatase activity of the purified enzyme fraction exhibited similar behavior on Sephadex G-100 and Mono Q colomns. These findings suggest that Zn(2+)-APase also exhibits Mg(2+)-dependent myo-inositol-1-phosphatase activity under physiological conditions.

Molecular mechanism for inhibition of twinfilin by phosphoinositides

DEFF Research Database (Denmark)

Hakala, Markku; Kalimeri, Maria; Enkavi, Giray

2018-01-01

actin-depolymerizing factor (ADF)/cofilin-like ADF homology domains of twinfilin bind phosphoinositides only with low affinity. Mutagenesis and biochemical experiments combined with atomistic molecular dynamics simulations reveal that the C-terminal tail of twinfilin interacts with membranes through......Membrane phosphoinositides control organization and dynamics of the actin cytoskeleton by regulating the activities of several key actin-binding proteins. Twinfilin is an evolutionarily conserved protein that contributes to cytoskeletal dynamics by interacting with actin monomers, filaments......, and the heterodimeric capping protein. Twinfilin also binds phosphoinositides, which inhibit its interactions with actin, but the underlying mechanism has remained unknown. Here, we show that the high-affinity binding site of twinfilin for phosphoinositides is located at the C-terminal tail region, whereas the two...

TORC1 regulates Pah1 phosphatidate phosphatase activity via the Nem1/Spo7 protein phosphatase complex.

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Emmanuelle Dubots

Full Text Available The evolutionarily conserved target of rapamycin complex 1 (TORC1 controls growth-related processes such as protein, nucleotide, and lipid metabolism in response to growth hormones, energy/ATP levels, and amino acids. Its deregulation is associated with cancer, type 2 diabetes, and obesity. Among other substrates, mammalian TORC1 directly phosphorylates and inhibits the phosphatidate phosphatase lipin-1, a central enzyme in lipid metabolism that provides diacylglycerol for the synthesis of membrane phospholipids and/or triacylglycerol as neutral lipid reserve. Here, we show that yeast TORC1 inhibits the function of the respective lipin, Pah1, to prevent the accumulation of triacylglycerol. Surprisingly, TORC1 regulates Pah1 in part indirectly by controlling the phosphorylation status of Nem1 within the Pah1-activating, heterodimeric Nem1-Spo7 protein phosphatase module. Our results delineate a hitherto unknown TORC1 effector branch that controls lipin function in yeast, which, given the recent discovery of Nem1-Spo7 orthologous proteins in humans, may be conserved.

Functional diversity of voltage-sensing phosphatases in two urodele amphibians.

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Mutua, Joshua; Jinno, Yuka; Sakata, Souhei; Okochi, Yoshifumi; Ueno, Shuichi; Tsutsui, Hidekazu; Kawai, Takafumi; Iwao, Yasuhiro; Okamura, Yasushi

2014-07-16

Voltage-sensing phosphatases (VSPs) share the molecular architecture of the voltage sensor domain (VSD) with voltage-gated ion channels and the phosphoinositide phosphatase region with the phosphatase and tensin homolog (PTEN), respectively. VSPs enzymatic activities are regulated by the motions of VSD upon depolarization. The physiological role of these proteins has remained elusive, and insights may be gained by investigating biological variations in different animal species. Urodele amphibians are vertebrates with potent activities of regeneration and also show diverse mechanisms of polyspermy prevention. We cloned cDNAs of VSPs from the testes of two urodeles; Hynobius nebulosus and Cynops pyrrhogaster, and compared their expression and voltage-dependent activation. Their molecular architecture is highly conserved in both Hynobius VSP (Hn-VSP) and Cynops VSP (Cp-VSP), including the positively-charged arginine residues in the S4 segment of the VSD and the enzymatic active site for substrate binding, yet the C-terminal C2 domain of Hn-VSP is significantly shorter than that of Cp-VSP and other VSP orthologs. RT-PCR analysis showed that gene expression pattern was distinct between two VSPs. The voltage sensor motions and voltage-dependent phosphatase activities were investigated electrophysiologically by expression in Xenopus oocytes. Both VSPs showed "sensing" currents, indicating that their voltage sensor domains are functional. The phosphatase activity of Cp-VSP was found to be voltage dependent, as shown by its ability to regulate the conductance of coexpressed GIRK2 channels, but Hn-VSP lacked such phosphatase activity due to the truncation of its C2 domain. © 2014 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Stretch induced endothelin-1 secretion by adult rat astrocytes involves calcium influx via stretch-activated ion channels (SACs)

International Nuclear Information System (INIS)

Ostrow, Lyle W.; Suchyna, Thomas M.; Sachs, Frederick

2011-01-01

Highlights: → Endothelin-1 expression by adult rat astrocytes correlates with cell proliferation. → Stretch-induced ET-1 is inhibited by GsMtx-4, a specific inhibitor of Ca 2+ permeant SACs. → The less specific SAC inhibitor streptomycin also inhibits ET-1 secretion. → Stretch-induced ET-1 production depends on a calcium influx. → SAC pharmacology may provide a new class of therapeutic agents for CNS pathology. -- Abstract: The expression of endothelins (ETs) and ET-receptors is often upregulated in brain pathology. ET-1, a potent vasoconstrictor, also inhibits the expression of astrocyte glutamate transporters and is mitogenic for astrocytes, glioma cells, neurons, and brain capillary endothelia. We have previously shown that mechanical stress stimulates ET-1 production by adult rat astrocytes. We now show in adult astrocytes that ET-1 production is driven by calcium influx through stretch-activated ion channels (SACs) and the ET-1 production correlates with cell proliferation. Mechanical stimulation using biaxial stretch ( 2+ threshold. This coupling of mechanical stress to the astrocyte endothelin system through SACs has treatment implications, since all pathology deforms the surrounding parenchyma.

Evidence from bioinformatics, expression and inhibition studies of phosphoinositide-3 kinase signalling in Giardia intestinalis

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Crompton Mark R

2006-05-01

Full Text Available Abstract Background Giardia intestinalis is a parasitic protozoan and major cause of diarrhoeal disease. Disease transmission is dependent on the ability of the parasite to differentiate back and forth between an intestine-colonising trophozoite and an environmentally-resistant infective cyst. Our current understanding of the intracellular signalling mechanisms that regulate parasite replication and differentiation is limited, yet such information could suggest new methods of disease control. Phosphoinositide-3 kinase (PI3K signalling pathways have a central involvement in many vital eukaryotic processes, such as regulation of cell growth, intracellular membrane trafficking and cell motility. Here we present evidence for the existence of functional PI3K intracellular signalling pathways in G. intestinalis. Results We have identified and characterised two genes, Gipi3k1 and Gipi3k2, which encode putative PI3Ks. Both genes are expressed in trophozoites and encysting cells, suggesting a possible role of GiPI3K1 and GiPI3K2 in regulating giardial growth and differentiation. Extensive nucleotide and amino acid sequence characterisation predicts that both encoded PI3Ks are functional as indicated by the presence of highly conserved structural domains and essential catalytic residues. The inhibitory effect of the PI3K inhibitor LY294002 on trophozoite proliferation also supports their functionality. Phylogenetic analysis supports the identity of GiPI3K1 as a Class I isoform and GiPI3K2 as a Class III isoform. In addition, giardial genes encoding putative homologues of phosphoinositide-metabolising enzymes such as PTEN, MTM, PIPkin and PI 5-phosphatase as well as downstream effectors with phosphoinositide-binding domains have been identified, placing GiPI3K1 and GiPI3K2 in a broader signalling context. Compared with twenty-six PI3Ks from other organisms, GiPI3K1 and GiPI3K2 are unique in that they contain large insertions within their highly conserved

Performance Analysis of Wavelength Multiplexed Sac Ocdma Codes in Beat Noise Mitigation in Sac Ocdma Systems

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Alhassan, A. M.; Badruddin, N.; Saad, N. M.; Aljunid, S. A.

2013-07-01

In this paper we investigate the use of wavelength multiplexed spectral amplitude coding (WM SAC) codes in beat noise mitigation in coherent source SAC OCDMA systems. A WM SAC code is a low weight SAC code, where the whole code structure is repeated diagonally (once or more) in the wavelength domain to achieve the same cardinality as a higher weight SAC code. Results show that for highly populated networks, the WM SAC codes provide better performance than SAC codes. However, for small number of active users the situation is reversed. Apart from their promising improvement in performance, these codes are more flexible and impose less complexity on the system design than their SAC counterparts.

Coordinated Expression of Phosphoinositide Metabolic Genes during Development and Aging of Human Dorsolateral Prefrontal Cortex.

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Stanley I Rapoport

Full Text Available Phosphoinositides, lipid-signaling molecules, participate in diverse brain processes within a wide metabolic cascade.Gene transcriptional networks coordinately regulate the phosphoinositide cascade during human brain Development and Aging.We used the public BrainCloud database for human dorsolateral prefrontal cortex to examine age-related expression levels of 49 phosphoinositide metabolic genes during Development (0 to 20+ years and Aging (21+ years.We identified three groups of partially overlapping genes in each of the two intervals, with similar intergroup correlations despite marked phenotypic differences between Aging and Development. In each interval, ITPKB, PLCD1, PIK3R3, ISYNA1, IMPA2, INPPL1, PI4KB, and AKT1 are in Group 1, PIK3CB, PTEN, PIK3CA, and IMPA1 in Group 2, and SACM1L, PI3KR4, INPP5A, SYNJ1, and PLCB1 in Group 3. Ten of the genes change expression nonlinearly during Development, suggesting involvement in rapidly changing neuronal, glial and myelination events. Correlated transcription for some gene pairs likely is facilitated by colocalization on the same chromosome band.Stable coordinated gene transcriptional networks regulate brain phosphoinositide metabolic pathways during human Development and Aging.

Pst I restriction fragment length polymorphism of the human placental alkaline phosphatase gene in normal placentae and tumors

International Nuclear Information System (INIS)

Tsavaler, L.; Penhallow, R.C.; Kam, W.; Sussman, H.H.

1987-01-01

The structure of the human placental alkaline phosphatase gene from normal term placentae was studied by restriction enzyme digestion and Southern blot analysis using a cDNA probe to the gene for the placental enzyme. The DNA digests fall into three distinct patterns based on the presence and intensity of an extra 1.1-kilobase Pst I Band. The extra 1.1-kilobase band is present in 9 of 27 placenta samples, and in 1 of these samples the extra band is present at double intensity. No polymorphism was revealed by digestion with restriction enzymes EcoRI, Sma I, BamHI, or Sac I. The extra Pst I-digestion site may lie in a noncoding region of the gene because no correlation was observed between the restriction fragment length polymorphism and the common placental alkaline phosphatase alleles identified by starch gel electrophoresis. In addition, because placental alkaline phosphatase is frequently re-expressed in neoplasms, the authors examined tissue from ovarian, testicular, and endometrial tumors and from BeWo choriocarcinoma cells in culture. The Pst I-DNA digestion patterns from these cells and tissues were identical to those seen in the normal ovary and term placentae. The consistent reproducible digestion patterns seen in DNA from normal and tumor tissue indicate that a major gene rearrangement is not the basis for the ectopic expression of placental alkaline phosphatase in neoplasia

Effect of aging on alpha-1 adrenergic stimulation of phosphoinositide hydrolysis in various regions of rat brain

International Nuclear Information System (INIS)

Burnett, D.M.; Bowyer, J.F.; Masserano, J.M.; Zahniser, N.R.

1990-01-01

The effects of aging were examined on the ability of alpha-1 adrenergic receptor agonists to stimulate phosphoinositide hydrolysis in three brain regions. Tissue minces of thalamus, cerebral cortex and hippocampus from 3-, 18- and 28-month-old male Fischer 344 rats were prelabeled with [ 3 H]myoinositol. Exposure of these prelabeled minces to phenylephrine and (-)-norepinephrine revealed that accumulation of [ 3 H]inositol phosphates was selectively reduced by 20 to 30% in the thalamus and cerebral cortex of the oldest age group. Analysis of concentration-response and competition binding curves indicated that this decrease was due to diminished agonist efficacy rather than diminished receptor affinity. The reduction in responsiveness to phenylephrine and (-)-norepinephrine in the cerebral cortex and the lack of any changes in the hippocampus parallel previously reported changes in the density of alpha-1 adrenergic receptors with aging. These data indicate that the ability of alpha-1 adrenergic receptor agonists to stimulate phosphoinositide hydrolysis is reduced in some, but not all, brain regions of aged Fischer 344 rats

Phosphoinositides II: the diverse biological functions

National Research Council Canada - National Science Library

Balla, Tamas, Dr; Wymann, Matthias; York, John D

2012-01-01

..., inflammation, neurodegenerative, cardiovascular, metabolic disease and more. In two volumes, this book elucidates the crucial mechanisms that control the dynamics of phosphoinositide conversion...

Serotonin-stimulated phosphoinositide turnover: mediation by the S2 binding site in rat cerebral cortex but not in subcortical regions

International Nuclear Information System (INIS)

Conn, P.J.; Sanders-Bush, E.

1985-01-01

In rat cerebral cortex, serotonin (5-HT) stimulates phosphoinositide turnover with an EC50 of 1 microM in the presence of pargyline. The EC50 is 16-fold higher in the absence of pargyline. Selective S2 antagonists inhibit 5-HT-stimulated phosphoinositide turnover. Schild analysis of the blockade by ketanserin of the 5-HT effect gives an estimated Kd of ketanserin for the phosphoinositide-linked receptor of 11.7 nM, which agrees with the Kd (3.5 nM) of [ 3 H]ketanserin for the S2 site. Furthermore, MK-212, 5-HT and 5-fluorotryptamine stimulate phosphoinositide turnover with potencies that resemble their potencies at the S2 but not the S1 binding site. Of 11 agonists tested, the tryptamine derivatives tend to be more efficacious than the piperazine derivatives. The selective S1 agonist 8-hydroxy-2-(di-N-propylamino)tetralin is inactive at stimulating phosphoinositide turnover. No significant relationship exists between the regional distributions of 5-HT-stimulated phosphoinositide turnover and S2 binding sites. Furthermore, the S2 antagonist ketanserin is less potent and less efficacious in hippocampus and limbic forebrain than in cerebral cortex. These data suggest that 5-HT-stimulated phosphoinositide turnover is linked to the S2 binding site in rat cerebral cortex. However, 5-HT increases phosphoinositide turnover in subcortical regions by mechanisms other than stimulation of the S2 receptor

Crystal structure of the cytoplasmic phosphatase and tensin homolog (PTEN)-like region of Ciona intestinalis voltage-sensing phosphatase provides insight into substrate specificity and redox regulation of the phosphoinositide phosphatase activity.

Science.gov (United States)

Matsuda, Makoto; Takeshita, Kohei; Kurokawa, Tatsuki; Sakata, Souhei; Suzuki, Mamoru; Yamashita, Eiki; Okamura, Yasushi; Nakagawa, Atsushi

2011-07-01

Ciona intestinalis voltage-sensing phosphatase (Ci-VSP) has a transmembrane voltage sensor domain and a cytoplasmic region sharing similarity to the phosphatase and tensin homolog (PTEN). It dephosphorylates phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol 3,4,5-trisphosphate upon membrane depolarization. The cytoplasmic region is composed of a phosphatase domain and a putative membrane interaction domain, C2. Here we determined the crystal structures of the Ci-VSP cytoplasmic region in three distinct constructs, wild-type (248-576), wild-type (236-576), and G365A mutant (248-576). The crystal structure of WT-236 and G365A-248 had the disulfide bond between the catalytic residue Cys-363 and the adjacent residue Cys-310. On the other hand, the disulfide bond was not present in the crystal structure of WT-248. These suggest the possibility that Ci-VSP is regulated by reactive oxygen species as found in PTEN. These structures also revealed that the conformation of the TI loop in the active site of the Ci-VSP cytoplasmic region was distinct from the corresponding region of PTEN; Ci-VSP has glutamic acid (Glu-411) in the TI loop, orienting toward the center of active site pocket. Mutation of Glu-411 led to acquirement of increased activity toward phosphatidylinositol 3,5-bisphosphate, suggesting that this site is required for determining substrate specificity. Our results provide the basic information of the enzymatic mechanism of Ci-VSP.

Structure-Based Design of Potent and Selective 3-Phosphoinositide-Dependent Kinase-1 (PDK1) Inhibitors

Energy Technology Data Exchange (ETDEWEB)

Medina, Jesus R.; Becker, Christopher J.; Blackledge, Charles W.; Duquenne, Celine; Feng, Yanhong; Grant, Seth W.; Heerding, Dirk; Li, William H.; Miller, William H.; Romeril, Stuart P.; Scherzer, Daryl; Shu, Arthur; Bobko, Mark A.; Chadderton, Antony R.; Dumble, Melissa; Gardiner, Christine M.; Gilbert, Seth; Liu, Qi; Rabindran, Sridhar K.; Sudakin, Valery; Xiang, Hong; Brady, Pat G.; Campobasso, Nino; Ward, Paris; Axten, Jeffrey M. (GSKPA)

2014-10-02

Phosphoinositide-dependent protein kinase-1(PDK1) is a master regulator of the AGC family of kinases and an integral component of the PI3K/AKT/mTOR pathway. As this pathway is among the most commonly deregulated across all cancers, a selective inhibitor of PDK1 might have utility as an anticancer agent. Herein we describe our lead optimization of compound 1 toward highly potent and selective PDK1 inhibitors via a structure-based design strategy. The most potent and selective inhibitors demonstrated submicromolar activity as measured by inhibition of phosphorylation of PDK1 substrates as well as antiproliferative activity against a subset of AML cell lines. In addition, reduction of phosphorylation of PDK1 substrates was demonstrated in vivo in mice bearing OCl-AML2 xenografts. These observations demonstrate the utility of these molecules as tools to further delineate the biology of PDK1 and the potential pharmacological uses of a PDK1 inhibitor.

Dihydrotestosterone induces SREBP-1 expression and lipogenesis through the phosphoinositide 3-kinase/Akt pathway in HaCaT cells

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Zhou Bing-rong

2012-11-01

Full Text Available Abstract Background The purpose of this study was to investigate the effects and mechanisms of dihydrotestosterone (DHT-induced expression of sterol regulatory element binding protein-1 (SREBP-1, and the synthesis and secretion of lipids, in HaCaT cells. HaCaT cells were treated with DHT and either the phosphoinositide 3-kinase inhibitor LY294002 or the extracellular-signal-regulated kinase (ERK inhibitor PD98059. Real time-PCR, Western blot, Oil Red staining and flow cytometry were employed to examine the mRNA and protein expressions of SREBP-1, the gene transcription of lipid synthesis, and lipid secretion in HaCaT cells. Findings We found that DHT upregulated mRNA and protein expressions of SREBP-1. DHT also significantly upregulated the transcription of lipid synthesis-related genes and increased lipid secretion, which can be inhibited by the addition of LY294002. Conclusions Collectively, these results indicate that DHT induces SREBP-1 expression and lipogenesis in HaCaT cells via activation of the phosphoinositide 3-kinase/Akt Pathway.

Displacement affinity chromatography of protein phosphatase one (PP1 complexes

Directory of Open Access Journals (Sweden)

Gourlay Robert

2008-11-01

Full Text Available Abstract Background Protein phosphatase one (PP1 is a ubiquitously expressed, highly conserved protein phosphatase that dephosphorylates target protein serine and threonine residues. PP1 is localized to its site of action by interacting with targeting or regulatory proteins, a majority of which contains a primary docking site referred to as the RVXF/W motif. Results We demonstrate that a peptide based on the RVXF/W motif can effectively displace PP1 bound proteins from PP1 retained on the phosphatase affinity matrix microcystin-Sepharose. Subsequent co-immunoprecipitation experiments confirmed that each identified binding protein was either a direct PP1 interactor or was in a complex that contains PP1. Our results have linked PP1 to numerous new nuclear functions and proteins, including Ki-67, Rif-1, topoisomerase IIα, several nuclear helicases, NUP153 and the TRRAP complex. Conclusion This modification of the microcystin-Sepharose technique offers an effective means of purifying novel PP1 regulatory subunits and associated proteins and provides a simple method to uncover a link between PP1 and additional cellular processes.

The Sac Actun System, Quintana Roo, Mexico; Sistema Sac Actun, Quintana Roo, Mexico

Energy Technology Data Exchange (ETDEWEB)

Kambesis, P. N.; Coke, J. G.

2016-07-01

The Sac Actun system, located in northeast Quintana Roo, Mexico, is among the most extensive underwater cave systems located along the Caribbean coast of the Yucatan Peninsula. The cave is composed of linear phreatic conduits that have two forms. The coastal sections of the Sac Actun system are characterized by low horizontal tunnels that form mazes paralleling the coast and rudimentary conduits broken by fracture-controlled rooms. Inland passages are fault/fracture controlled, have a linear, anastomotic configuration, and align perpendicular to the coast. Access to the cave system is gained through cenotes which are the portals into the Yucatan underwater cave systems. The occurrence of drowned speleothems in many parts of the cave system, and sections of air-filled upper level passages are indicative of major fluctuations in sea level. The Sac Actun system is part of one of the most extensive and significant eogenetic karst aquifers in the world. The development of the Sac Actun system, as well as the many other caves systems along the Yucatan Caribbean Coast is controlled by the coastal hydrologic regime, driven by glacio-eustatics, and influenced by stratigraphic and structural controls. The karstic permeability of the aquifer makes it and the Sac Actun system vulnerable to the anthropogenic impacts of increased population growth, quarries, and infrastructure development associated with the burgeoning tourist industry that dominates land use in the region. (Author)

Cloning and characterization of a G protein-activated human phosphoinositide-3 kinase.

Science.gov (United States)

Stoyanov, B; Volinia, S; Hanck, T; Rubio, I; Loubtchenkov, M; Malek, D; Stoyanova, S; Vanhaesebroeck, B; Dhand, R; Nürnberg, B

1995-08-04

Phosphoinositide-3 kinase activity is implicated in diverse cellular responses triggered by mammalian cell surface receptors and in the regulation of protein sorting in yeast. Receptors with intrinsic and associated tyrosine kinase activity recruit heterodimeric phosphoinositide-3 kinases that consist of p110 catalytic subunits and p85 adaptor molecules containing Src homology 2 (SH2) domains. A phosphoinositide-3 kinase isotype, p110 gamma, was cloned and characterized. The p110 gamma enzyme was activated in vitro by both the alpha and beta gamma subunits of heterotrimeric guanosine triphosphate (GTP)-binding proteins (G proteins) and did not interact with p85. A potential pleckstrin homology domain is located near its amino terminus. The p110 gamma isotype may link signaling through G protein-coupled receptors to the generation of phosphoinositide second messengers phosphorylated in the D-3 position.

A Demonstration of the System Assessment Capability (SAC) Rev. 1 Software for the Hanford Remediation Assessment Project

International Nuclear Information System (INIS)

Eslinger, Paul W.; Kincaid, Charles T.; Nichols, William E.; Wurstner, Signe K.

2006-01-01

The System Assessment Capability (SAC) is a suite of interrelated computer codes that provides the capability to conduct large-scale environmental assessments on the Hanford Site. Developed by Pacific Northwest National Laboratory for the Department of Energy, SAC models the fate and transport of radioactive and chemical contaminants, starting with the inventory of those contaminants in waste sites, simulating transport through the environment, and continuing on through impacts to the environment and humans. Separate modules in the SAC address inventory, release from waste forms, water flow and mass transport in the vadose zone, water flow and mass transport in the groundwater, water flow and mass transport in the Columbia River, air transport, and human and ecological impacts. The SAC supports deterministic analyses as well as stochastic analyses using a Monte Carlo approach, enabling SAC users to examine the effect of uncertainties in a number of key parameters. The initial assessment performed with the SAC software identified a number of areas where both the software and the analysis approach could be improved. Since that time the following six major software upgrades have been made: (1) An air pathway model was added to support all-pathway analyses. (2) Models for releases from glass waste forms, buried graphite reactor cores, and buried naval reactor compartments were added. (3) An air-water dual-phase model was added to more accurately track the movement of volatile contaminants in the vadose zone. (4) The ability to run analyses was extended from 1,000 years to 10,000 years or longer after site closure. (5) The vadose zone flow and transport model was upgraded to support two-dimensional or three-dimensional analyses. (6) The ecological model and human risk models were upgraded so the concentrations of contaminants in food products consumed by humans are produced by the ecological model. This report documents the functions in the SAC software and provides a

A Demonstration of the System Assessment Capability (SAC) Rev. 1 Software for the Hanford Remediation Assessment Project

Energy Technology Data Exchange (ETDEWEB)

Eslinger, Paul W.; Kincaid, Charles T.; Nichols, William E.; Wurstner, Signe K.

2006-11-06

The System Assessment Capability (SAC) is a suite of interrelated computer codes that provides the capability to conduct large-scale environmental assessments on the Hanford Site. Developed by Pacific Northwest National Laboratory for the Department of Energy, SAC models the fate and transport of radioactive and chemical contaminants, starting with the inventory of those contaminants in waste sites, simulating transport through the environment, and continuing on through impacts to the environment and humans. Separate modules in the SAC address inventory, release from waste forms, water flow and mass transport in the vadose zone, water flow and mass transport in the groundwater, water flow and mass transport in the Columbia River, air transport, and human and ecological impacts. The SAC supports deterministic analyses as well as stochastic analyses using a Monte Carlo approach, enabling SAC users to examine the effect of uncertainties in a number of key parameters. The initial assessment performed with the SAC software identified a number of areas where both the software and the analysis approach could be improved. Since that time the following six major software upgrades have been made: (1) An air pathway model was added to support all-pathway analyses. (2) Models for releases from glass waste forms, buried graphite reactor cores, and buried naval reactor compartments were added. (3) An air-water dual-phase model was added to more accurately track the movement of volatile contaminants in the vadose zone. (4) The ability to run analyses was extended from 1,000 years to 10,000 years or longer after site closure. (5) The vadose zone flow and transport model was upgraded to support two-dimensional or three-dimensional analyses. (6) The ecological model and human risk models were upgraded so the concentrations of contaminants in food products consumed by humans are produced by the ecological model. This report documents the functions in the SAC software and provides a

Distinctive changes in plasma membrane phosphoinositides underlie differential regulation of TRPV1 in nociceptive neurons.

Science.gov (United States)

Lukacs, Viktor; Yudin, Yevgen; Hammond, Gerald R; Sharma, Esseim; Fukami, Kiyoko; Rohacs, Tibor

2013-07-10

Transient Receptor Potential Vanilloid 1 (TRPV1) is a polymodal, Ca(2+)-permeable cation channel crucial to regulation of nociceptor responsiveness. Sensitization of TRPV1 by G-protein coupled receptor (GPCR) agonists to its endogenous activators, such as low pH and noxious heat, is a key factor in hyperalgesia during tissue injury as well as pathological pain syndromes. Conversely, chronic pharmacological activation of TRPV1 by capsaicin leads to calcium influx-induced adaptation of the channel. Paradoxically, both conditions entail activation of phospholipase C (PLC) enzymes, which hydrolyze phosphoinositides. We found that in sensory neurons PLCβ activation by bradykinin led to a moderate decrease in phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2), but no sustained change in the levels of its precursor PI(4)P. Preventing this selective decrease in PI(4,5)P2 inhibited TRPV1 sensitization, while selectively decreasing PI(4,5)P2 independently of PLC potentiated the sensitizing effect of protein kinase C (PKC) on the channel, thereby inducing increased TRPV1 responsiveness. Maximal pharmacological TRPV1 stimulation led to a robust decrease of both PI(4,5)P2 and its precursor PI(4)P in sensory neurons. Attenuating the decrease of either lipid significantly reduced desensitization, and simultaneous reduction of PI(4,5)P2 and PI(4)P independently of PLC inhibited TRPV1. We found that, on the mRNA level, the dominant highly Ca(2+)-sensitive PLC isoform in dorsal root ganglia is PLCδ4. Capsaicin-induced desensitization of TRPV1 currents was significantly reduced, whereas capsaicin-induced nerve impulses in the skin-nerve preparation increased in mice lacking this isoform. We propose a comprehensive model in which differential changes in phosphoinositide levels mediated by distinct PLC isoforms result in opposing changes in TRPV1 activity.

Diagnostic imaging features of normal anal sacs in dogs and cats.

Science.gov (United States)

Jung, Yechan; Jeong, Eunseok; Park, Sangjun; Jeong, Jimo; Choi, Ul Soo; Kim, Min-Su; Kim, Namsoo; Lee, Kichang

2016-09-30

This study was conducted to provide normal reference features for canine and feline anal sacs using ultrasound, low-field magnetic resonance imaging (MRI) and radiograph contrast as diagnostic imaging tools. A total of ten clinically normal beagle dogs and eight clinically normally cats were included. General radiography with contrast, ultrasonography and low-field MRI scans were performed. The visualization of anal sacs, which are located at distinct sites in dogs and cats, is possible with a contrast study on radiography. Most surfaces of the anal sacs tissue, occasionally appearing as a hyperechoic thin line, were surrounded by the hypoechoic external sphincter muscle on ultrasonography. The normal anal sac contents of dogs and cats had variable echogenicity. Signals of anal sac contents on low-field MRI varied in cats and dogs, and contrast medium using T1-weighted images enhanced the anal sac walls more obviously than that on ultrasonography. In conclusion, this study provides the normal features of anal sacs from dogs and cats on diagnostic imaging. Further studies including anal sac evaluation are expected to investigate disease conditions.

Dephosphorylation of chicken cardiac myofibril C-protein by protein phosphatases 1 and 2A

International Nuclear Information System (INIS)

Thysseril, T.J.; Hegazy, M.G.; Schlender, K.K.

1987-01-01

C-Protein, which is a regulatory component of cardiac muscle myofibrils, is phosphorylated in response to β-adrenergic agonists by a cAMP-dependent mechanism and dephosphorylated in response to cholinergic agonists. It is believed that the cAMP-dependent phosphorylation is due to cAMP-dependent protein kinase. The protein phosphatase(s) involved in the dephosphorylation of C-protein has not been determined. In this study, chicken cardiac C-protein was phosphorylated with the cAMP-dependent protein kinase to about 3 mol phosphate/mol C-protein. Incubation of [ 32 P]C-protein with the catalytic subunit of protein phosphatase 1 or 2A rapidly removed 30-40% of 32 [P]. Phosphopeptide maps and phosphoamino acid analysis revealed that the major site(s) dephosphorylated by either phosphatase was a phosphothreonine residue(s) located on the same tryptic peptide and on the same CNBr fragment. Increasing the incubation period or the phosphatase concentration did not result in any further dephosphorylation of C-protein by phosphatase 1, but phosphatase 2A completely dephosphorylated C-protein. Preliminary studies showed that the major protein phosphatase associated with the myofibril was phosphatase 2A. These results indicate the phosphatase 2A may be important in the regulation of the phosphorylation state of C-protein

Phosphoinositides in Ca(2+) signaling and excitation-contraction coupling in skeletal muscle: an old player and newcomers.

Science.gov (United States)

Csernoch, Laszlo; Jacquemond, Vincent

2015-12-01

Since the postulate, 30 years ago, that phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P 2) as the precursor of inositol 1,4,5-trisphosphate (Ins(1,4,5)P 3) would be critical for skeletal muscle excitation-contraction (EC) coupling, the issue of whether phosphoinositides (PtdInsPs) may have something to do with Ca(2+) signaling in muscle raised limited interest, if any. In recent years however, the PtdInsP world has expanded considerably with new functions for PtdIns(4,5)P 2 but also with functions for the other members of the PtdInsP family. In this context, the discovery that genetic deficiency in a PtdInsP phosphatase has dramatic consequences on Ca(2+) homeostasis in skeletal muscle came unanticipated and opened up new perspectives in regards to how PtdInsPs modulate muscle Ca(2+) signaling under normal and disease conditions. This review intends to make an update of the established, the questioned, and the unknown regarding the role of PtdInsPs in skeletal muscle Ca(2+) homeostasis and EC coupling, with very specific emphasis given to Ca(2+) signals in differentiated skeletal muscle fibers.

Decrease in platelet activating factor stimulated phosphoinositide turnover during storage of human platelets in plasma

International Nuclear Information System (INIS)

Carter, M.G.; Shukla, S.D.

1987-01-01

Human platelet concentrate from the American Red Cross Blood Center was stored at 24 degree C in a shaker and aliquots were taken out at time intervals aseptically. Platelet activating factor (PAF) stimulated turnover of phosphoinositide (PPI) was monitored by assaying 32 P incorporation into phosphoinositides using platelet rich plasma (PRP). Platelets in PRP were incubated with 1 x 10 -7 M PAF at 37 degree C with gentle shaking and after 5 min their lipids were extracted and analysed by TLC for 32 P-phosphoinositides. The percent stimulation of 32 P incorporation by PAF (over control) into PPI was approximately 250, 100, 60, 25 and 20 on days 1, 2, 3, 5 and 6, respectively. This indicated a dramatic decrease in PAF responsive turnover of platelet PPI during storage. These findings have important implications in relation to PAF receptor activity and viability of platelets at different periods of storage

Endolymphatic Sac Decompression With Intra-Sac Dexamethasone Injection in Menière's Disease.

Science.gov (United States)

Bojrab, Dennis I; LaRouere, Michael J; Bojrab, Dennis I; Babu, Seilesh C; Sargent, Eric W; Chan, Eleanor Y; Hong, Robert S

2018-06-01

Endolymphatic sac decompression surgery (ELSD) may be used to treat patients who have Menière's 's disease refractory to medical therapy. In this study, we investigated whether or not the injection of steroid into the endolymphatic sac at the time of ELSD provides additional benefit to patient outcomes. Randomized prospective single-blinded placebo-controlled study. Tertiary center. Patients with Menière's disease with poorly controlled vertigo despite medical therapy and serviceable hearing that were offered ELSD. Patients randomized into two groups, with control group (n = 17) undergone ELSD without steroid injection and experimental group undergone ELSD with steroid injection (n = 18) MAIN OUTCOME MEASURE(S):: Audiogram, dizziness handicap inventory, tinnitus handicap inventory, frequency of vertigo spells, functional level scale, and quality of life were obtained at multiple intervals from preoperatively to 24 months postoperatively. ELSD resulted in a statistically significant improvement in vertigo control whether or not steroid was injected into the endolymphatic sac at the time of surgery. However, no additional benefit was observed with the addition of intra-sac steroid injection. No statistical difference in pure-tone average, tinnitus handicap inventory, dizziness handicap inventory, or quality of life was observed between the steroid and nonsteroid surgical groups up to 24 months postoperatively. ELSD is an effective treatment for Menière's disease refractory to medical therapy; however, the addition of intra-sac steroid injection at the time of surgery does not seem to result in a further improvement in patient outcomes.

SacB-SacR gene cassette as the negative selection marker to suppress Agrobacterium overgrowth in Agrobacterium-mediated plant transformation

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Yiming Liu

2016-10-01

Full Text Available Agrobacterium overgrowth is a common problem in Agrobacterium-mediated plant transfor-mation. To suppress the Agrobacterium overgrowth, various antibiotics have been used during plant tissue culture steps. The antibiotics are expensive and may adversely affect plant cell differentiation and reduce plant transformation efficiency. The SacB-SacR proteins are toxic to most Agrobacterium tumefaciens strains when they are grown on culture medium sup¬plemented with sucrose. Therefore, SacB-SacR genes can be used as negative selection markers to suppress the overgrowth of Agrobacterium tumefaciens in the plant tissue culture process. We generated a mutant Agrobacterium tumefaciens strain GV2260 (recA-SacB/R that has the SacB-SacR cassette inserted into the bacterial genome at the recA gene locus. The mutant Agrobacterium strain is sensitive to sucrose but maintains its ability to transform plant cells in both transient and stable transformation assays. We demonstrated that the mutant strain GV2260 (recA-SacB/R can be inhibited by sucrose that reduces the overgrowth of Agrobacterium and therefore improves the plant transformation efficiency. We employed GV2260 (recA-SacB/R to generate stable transgenic N. benthamiana plants expressing a CRISPR-Cas9 for knocking out a WRKY transcrip¬tion factor.

Genome-wide analysis of the phosphoinositide kinome from two ciliates reveals novel evolutionary links for phosphoinositide kinases in eukaryotic cells.

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George Leondaritis

Full Text Available BACKGROUND: The complexity of phosphoinositide signaling in higher eukaryotes is partly due to expansion of specific families and types of phosphoinositide kinases (PIKs that can generate all phosphoinositides via multiple routes. This is particularly evident in the PI3Ks and PIPKs, and it is considered an evolutionary trait associated with metazoan diversification. Yet, there are limited comprehensive studies on the PIK repertoire of free living unicellular organisms. METHODOLOGY/PRINCIPAL FINDINGS: We undertook a genome-wide analysis of putative PIK genes in two free living ciliated cells, Tetrahymena and Paramecium. The Tetrahymena thermophila and Paramecium tetraurelia genomes were probed with representative kinases from all families and types. Putative homologs were verified by EST, microarray and deep RNA sequencing database searches and further characterized for domain structure, catalytic efficiency, expression patterns and phylogenetic relationships. In total, we identified and characterized 22 genes in the Tetrahymena thermophila genome and 62 highly homologues genes in Paramecium tetraurelia suggesting a tight evolutionary conservation in the ciliate lineage. Comparison to the kinome of fungi reveals a significant expansion of PIK genes in ciliates. CONCLUSIONS/SIGNIFICANCE: Our study highlights four important aspects concerning ciliate and other unicellular PIKs. First, ciliate-specific expansion of PI4KIII-like genes. Second, presence of class I PI3Ks which, at least in Tetrahymena, are associated with a metazoan-type machinery for PIP3 signaling. Third, expansion of divergent PIPK enzymes such as the recently described type IV transmembrane PIPKs. Fourth, presence of possible type II PIPKs and presumably inactive PIKs (hence, pseudo-PIKs not previously described. Taken together, our results provide a solid framework for future investigation of the roles of PIKs in ciliates and indicate that novel functions and novel regulatory

Efficacy of Several Pesticide Products on Brown Widow Spider (Araneae: Theridiidae) Egg Sacs and Their Penetration Through the Egg Sac Silk.

Science.gov (United States)

Vetter, Richard S; Tarango, Jacob; Campbell, Kathleen A; Tham, Christine; Hayashi, Cheryl Y; Choe, Dong-Hwan

2016-02-01

Information on pesticide effects on spiders is less common than for insects; similar information for spider egg sacs is scarcer in the open literature. Spider egg sacs are typically covered with a protective silk layer. When pesticides are directly applied to egg sacs, the silk might prevent active ingredients from reaching the eggs, blocking their insecticidal effect. We investigated the impact of six water-based pesticide sprays and four oil-based aerosol products against egg sacs of brown widow spiders, Latrodectus geometricus C. L. Koch. All water-based spray products except one failed to provide significant mortality to egg sacs, resulting in successful spiderling emergence from treated egg sacs at a similar rate to untreated egg sacs. In contrast to water-based sprays, oil-based aerosols provided almost complete control, with 94-100% prevention of spiderling emergence. Penetration studies using colored pesticide products indicated that oil-based aerosols were significantly more effective in penetrating egg sac silk than were the water-based sprays, delivering the active ingredients on most (>99%) of the eggs inside the sac. The ability of pesticides to penetrate spider egg sac silk and deliver lethal doses of active ingredients to the eggs is discussed in relation to the chemical nature of egg sac silk proteins. Our study suggests that pest management procedures primarily relying on perimeter application of water-based sprays might not provide satisfactory control of brown widow spider eggs. Determination of the most effective active ingredients and carrier characteristics warrant further research to provide more effective control options for spider egg sacs. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Proteomic analysis of protein phosphatase Z1 from Candida albicans.

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Bernadett Márkus

Full Text Available Protein phosphatase Z is a "novel type" fungus specific serine/threonine protein phosphatase. Previously our research group identified the CaPPZ1 gene in the opportunistic pathogen Candida albicans and reported that the gene deletion had several important physiological consequences. In order to reveal the protein targets and the associated mechanisms behind the functions of the phosphatase a proteomic method was adopted for the comparison of the cappz1 deletion mutant and the genetically matching QMY23 control strain. Proteins extracted from the control and deletion mutant strains were separated by two-dimensional gel electrophoresis and the protein spots were stained with RuBPS and Pro-Q Diamond in order to visualize the total proteome and the phosphoproteome, respectively. The alterations in spot intensities were determined by densitometry and were analysed with the Delta2D (Decodon software. Spots showing significantly different intensities between the mutant and control strains were excised from the gels and were digested with trypsin. The resulting peptides were identified by LC-MS/MS mass spectrometry. As many as 15 protein spots were found that exhibited significant changes in their intensity upon the deletion of the phosphatase and 20 phosphoproteins were identified in which the level of phosphorylation was modified significantly in the mutant. In agreement with previous findings we found that the affected proteins function in protein synthesis, oxidative stress response, regulation of morphology and metabolism. Among these proteins we identified two potential CaPpz1 substrates (Eft2 and Rpp0 that may regulate the elongation step of translation. RT-qPCR experiments revealed that the expression of the genes coding for the affected proteins was not altered significantly. Thus, the absence of CaPpz1 exerted its effects via protein synthesis/degradation and phosphorylation/dephosphorylation. In addition, our proteomics data strongly

Proteomic analysis of protein phosphatase Z1 from Candida albicans

Science.gov (United States)

Pfliegler, Walter P.; Petrényi, Katalin; Boros, Enikő; Pócsi, István; Tőzsér, József; Dombrádi, Viktor

2017-01-01

Protein phosphatase Z is a “novel type” fungus specific serine/threonine protein phosphatase. Previously our research group identified the CaPPZ1 gene in the opportunistic pathogen Candida albicans and reported that the gene deletion had several important physiological consequences. In order to reveal the protein targets and the associated mechanisms behind the functions of the phosphatase a proteomic method was adopted for the comparison of the cappz1 deletion mutant and the genetically matching QMY23 control strain. Proteins extracted from the control and deletion mutant strains were separated by two-dimensional gel electrophoresis and the protein spots were stained with RuBPS and Pro-Q Diamond in order to visualize the total proteome and the phosphoproteome, respectively. The alterations in spot intensities were determined by densitometry and were analysed with the Delta2D (Decodon) software. Spots showing significantly different intensities between the mutant and control strains were excised from the gels and were digested with trypsin. The resulting peptides were identified by LC-MS/MS mass spectrometry. As many as 15 protein spots were found that exhibited significant changes in their intensity upon the deletion of the phosphatase and 20 phosphoproteins were identified in which the level of phosphorylation was modified significantly in the mutant. In agreement with previous findings we found that the affected proteins function in protein synthesis, oxidative stress response, regulation of morphology and metabolism. Among these proteins we identified two potential CaPpz1 substrates (Eft2 and Rpp0) that may regulate the elongation step of translation. RT-qPCR experiments revealed that the expression of the genes coding for the affected proteins was not altered significantly. Thus, the absence of CaPpz1 exerted its effects via protein synthesis/degradation and phosphorylation/dephosphorylation. In addition, our proteomics data strongly suggested a role for

Allosteric substrate switching in a voltage-sensing lipid phosphatase.

Science.gov (United States)

Grimm, Sasha S; Isacoff, Ehud Y

2016-04-01

Allostery provides a critical control over enzyme activity, biasing the catalytic site between inactive and active states. We found that the Ciona intestinalis voltage-sensing phosphatase (Ci-VSP), which modifies phosphoinositide signaling lipids (PIPs), has not one but two sequential active states with distinct substrate specificities, whose occupancy is allosterically controlled by sequential conformations of the voltage-sensing domain (VSD). Using fast fluorescence resonance energy transfer (FRET) reporters of PIPs to monitor enzyme activity and voltage-clamp fluorometry to monitor conformational changes in the VSD, we found that Ci-VSP switches from inactive to a PIP3-preferring active state when the VSD undergoes an initial voltage-sensing motion and then into a second PIP2-preferring active state when the VSD activates fully. This two-step allosteric control over a dual-specificity enzyme enables voltage to shape PIP concentrations in time, and provides a mechanism for the complex modulation of PIP-regulated ion channels, transporters, cell motility, endocytosis and exocytosis.

Allosteric substrate switching in a voltage sensing lipid phosphatase

Science.gov (United States)

Grimm, Sasha S.; Isacoff, Ehud Y.

2016-01-01

Allostery provides a critical control over enzyme activity, biasing the catalytic site between inactive and active states. We find the Ciona intestinalis voltage-sensing phosphatase (Ci-VSP), which modifies phosphoinositide signaling lipids (PIPs), to have not one but two sequential active states with distinct substrate specificities, whose occupancy is allosterically controlled by sequential conformations of the voltage sensing domain (VSD). Using fast FRET reporters of PIPs to monitor enzyme activity and voltage clamp fluorometry to monitor conformational changes in the VSD, we find that Ci-VSP switches from inactive to a PIP3-preferring active state when the VSD undergoes an initial voltage sensing motion and then into a second PIP2-preferring active state when the VSD activates fully. This novel 2-step allosteric control over a dual specificity enzyme enables voltage to shape PIP concentrations in time, and provides a mechanism for the complex modulation of PIP-regulated ion channels, transporters, cell motility and endo/exocytosis. PMID:26878552

Smc1β is required for activation of SAC during mouse oocyte meiosis.

Science.gov (United States)

Miao, Yilong; Zhou, Changyin; Cui, Zhaokang; Dai, Xiaoxin; Zhang, Mianqun; Lu, Yajuan; Xiong, Bo

2017-03-19

Smc1β is a meiosis-specific cohesin subunit that is essential for sister chromatid cohesion and DNA recombination. Previous studies have shown that Smc1β-deficient mice in both sexes are sterile. Ablation of Smc1β during male meiosis leads to the blockage of spermatogenesis in pachytene stage, and ablation of Smc1β during female meiosis generates a highly error-prone oocyte although it could develop to metaphase II stage. However, the underlying mechanisms regarding how Smc1β maintains the correct meiotic progression in mouse oocytes have not been clearly defined. Here, we find that GFP-fused Smc1β is expressed and localized to the chromosomes from GV to MII stages during mouse oocyte meiotic maturation. Knockdown of Smc1β by microinjection of gene-specific morpholino causes the impaired spindle apparatus and chromosome alignment which are highly correlated with the defective kinetochore-microtubule attachments, consequently resulting in a prominently higher incidence of aneuploid eggs. In addition, the premature extrusion of polar bodies and escape of metaphase I arrest induced by low dose of nocodazole treatment in Smc1β-depleted oocytes indicates that Smc1β is essential for activation of spindle assembly checkpoint (SAC) activity. Collectively, we identify a novel function of Smc1β as a SAC participant beyond its role in chromosome cohesion during mouse oocyte meiosis.

Molecular detection and in vitro antioxidant activity of S-allyl-L-cysteine (SAC) extracted from Allium sativum.

Science.gov (United States)

Sun, Y-E; Wang, W-D

2016-06-30

It is well known that Allium sativum has potential applications to clinical treatment of various cancers due to its remarkable ability in eliminating free radicals and increasing metabolism. An allyl-substituted cysteine derivative - S-allyl-L-cysteine (SAC) was separated and identified from Allium sativum. The extracted SAC was reacted with 1-pyrenemethanol to obtain pyrene-labelled SAC (Py-SAC) to give SAC fluorescence properties. Molecular detection of Py-SAC was conducted by steady-state fluorescence spectroscopy and time-resolved fluorescence method to quantitatively measure concentrations of Py-SAC solutions. The ability of removing 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical using Py-SAC was determined through oxygen radical absorbance capacity (ORAC). Results showed the activity of Py-SAC and Vitamin C (VC) with ORAC as index, the concentrations of Py-SAC and VC were 58.43 mg/L and 5.72 mg/L respectively to scavenge DPPH, and 8.16 mg/L and 1.67 mg/L to scavenge •OH respectively. Compared with VC, the clearance rates of Py-SAC to scavenge DPPH were much higher, Py-SAC could inhibit hydroxyl radical. The ability of removing radical showed a dose-dependent relationship within the scope of the drug concentration.

Endolymphatic sac involvement in bacterial meningitis

DEFF Research Database (Denmark)

Møller, Martin Nue; Brandt, Christian; Østergaard, Christian

2015-01-01

The commonest sequelae of bacterial meningitis are related to the inner ear. Little is known about the inner ear immune defense. Evidence suggests that the endolymphatic sac provides some protection against infection. A potential involvement of the endolymphatic sac in bacterial meningitis...... is largely unaccounted for, and thus the object of the present study. A well-established adult rat model of Streptococcus pneumoniae meningitis was employed. Thirty adult rats were inoculated intrathecally with Streptococcus pneumoniae and received no additional treatment. Six rats were sham...... days. Bacteria invaded the inner ear through the cochlear aquaduct. On days 5-6, the bacteria invaded the endolymphatic sac through the endolymphatic duct subsequent to invasion of the vestibular endolymphatic compartment. No evidence of direct bacterial invasion of the sac through the meninges...

Ovarian yolk sac tumour in a girl - case report.

Science.gov (United States)

Sharma, Charu; Shah, Hemanshi; Sisodiya Shenoy, Neha; Makhija, Deepa; Waghmare, Mukta

2017-01-01

Yolk sac tumours are rare ovarian malignancies accounting for less than 1% of malignant ovarian germ cell tumours. They are mostly seen in adolescents and young women and are usually unilateral making fertility preservation imperative. Raised alpha-feto protein level is the hallmark of this tumour. We describe stage III yolk sac tumour in a girl child.

Model of OSBP-Mediated Cholesterol Supply to Aichi Virus RNA Replication Sites Involving Protein-Protein Interactions among Viral Proteins, ACBD3, OSBP, VAP-A/B, and SAC1.

Science.gov (United States)

Ishikawa-Sasaki, Kumiko; Nagashima, Shigeo; Taniguchi, Koki; Sasaki, Jun

2018-04-15

Positive-strand RNA viruses, including picornaviruses, utilize cellular machinery for genome replication. Previously, we reported that each of the 2B, 2BC, 2C, 3A, and 3AB proteins of Aichi virus (AiV), a picornavirus, forms a complex with the Golgi apparatus protein ACBD3 and phosphatidylinositol 4-kinase IIIβ (PI4KB) at viral RNA replication sites (replication organelles [ROs]), enhancing PI4KB-dependent phosphatidylinositol 4-phosphate (PI4P) production. Here, we demonstrate AiV hijacking of the cellular cholesterol transport system involving oxysterol-binding protein (OSBP), a PI4P-binding cholesterol transfer protein. AiV RNA replication was inhibited by silencing cellular proteins known to be components of this pathway, OSBP, the ER membrane proteins VAPA and VAPB (VAP-A/B), the PI4P-phosphatase SAC1, and PI-transfer protein β. OSBP, VAP-A/B, and SAC1 were present at RNA replication sites. We also found various previously unknown interactions among the AiV proteins (2B, 2BC, 2C, 3A, and 3AB), ACBD3, OSBP, VAP-A/B, and SAC1, and the interactions were suggested to be involved in recruiting the component proteins to AiV ROs. Importantly, the OSBP-2B interaction enabled PI4P-independent recruitment of OSBP to AiV ROs, indicating preferential recruitment of OSBP among PI4P-binding proteins. Protein-protein interaction-based OSBP recruitment has not been reported for other picornaviruses. Cholesterol was accumulated at AiV ROs, and inhibition of OSBP-mediated cholesterol transfer impaired cholesterol accumulation and AiV RNA replication. Electron microscopy showed that AiV-induced vesicle-like structures were close to ER membranes. Altogether, we conclude that AiV directly recruits the cholesterol transport machinery through protein-protein interactions, resulting in formation of membrane contact sites between the ER and AiV ROs and cholesterol supply to the ROs. IMPORTANCE Positive-strand RNA viruses utilize host pathways to modulate the lipid composition of

Human papillomavirus: cause of epithelial lacrimal sac neoplasia?

DEFF Research Database (Denmark)

Sjö, Nicolai Christian; von Buchwald, Christian; Cassonnet, Patricia

2007-01-01

PURPOSE: Epithelial tumours of the lacrimal sac are rare but important entities that may carry grave prognoses. In this study the prevalence and possible role of human papillomavirus (HPV) infection in epithelial tumours of the lacrimal sac were evaluated. METHODS: Five papillomas and six...... 11 RNA was demonstrated in two papillomas. CONCLUSIONS: By analysing 11 epithelial lacrimal sac papillomas and carcinomas using PCR, DNA ISH and RNA ISH, we found HPV DNA in all investigated transitional epithelium tumours of the lacrimal sac. HPV RNA was present in two of eight epithelial lacrimal...... sac tumours positive for HPV DNA. As RNA degrades fast in paraffin-embedded tissue, only a small fraction of DNA-positive tumours can be expected to be RNA-positive. We therefore suggest that HPV infection is associated with the development of lacrimal sac papillomas and carcinomas....

Cloning and characterization of rat density-enhanced phosphatase-1, a protein tyrosine phosphatase expressed by vascular cells.

Science.gov (United States)

Borges, L G; Seifert, R A; Grant, F J; Hart, C E; Disteche, C M; Edelhoff, S; Solca, F F; Lieberman, M A; Lindner, V; Fischer, E H; Lok, S; Bowen-Pope, D F

1996-09-01

We have cloned from cultured vascular smooth muscle cells a protein tyrosine phosphatase, rat density-enhanced phosphatase-1 (rDEP-1), which is a probable rat homologue of DEP-1/HPTP eta. rDEP-1 is encoded by an 8.7-kb transcript and is expressed as a 180- to 220-kD protein. The rDEP-1 gene is located on human chromosome 11 (region p11.2) and on mouse chromosome 2 (region 2E). The cDNA sequence predicts a transmembrane protein consisting of a single phosphatase catalytic domain in the intracellular region, a single transmembrane domain, and eight fibronectin type III repeats in the extracellular region (GenBank accession number U40790). In situ hybridization analysis demonstrates that rDEP-1 is widely expressed in vivo but that expression is highest in cells that form epithelioid monolayers. In cultured cells with epitheliod morphology, including endothelial cells and newborn smooth muscle cells, but not in fibroblast-like cells, rDEP-1 transcript levels are dramatically upregulated as population density increases. In vivo, quiescent endothelial cells in normal arteries express relatively high levels of rDEP-1. During repair of vascular injury, expression of rDEP-1 is downregulated in migrating and proliferating endothelial cells. In vivo, rDEP-1 transcript levels are present in very high levels in megakaryocytes, and circulating plates have high levels of the rDEP-1 protein. In vitro, initiation of differentiation of the human megakaryoblastic cell line CHRF-288-11 with phorbol 12-myristate 13-acetate leads to a very strong upregulation of rDEP-1 transcripts. The deduced structure and the regulation of expression of rDEP-1 suggest that it may play a role in adhesion and/or signaling events involving cell-cell and cell-matrix contact.

Dynamics of Phosphoinositide-Dependent Signaling in Sympathetic Neurons

OpenAIRE

Kruse, Martin; Vivas, Oscar; Traynor-Kaplan, Alexis; Hille, Bertil

2016-01-01

In neurons, loss of plasma membrane phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] leads to a decrease in exocytosis and changes in electrical excitability. Restoration of PI(4,5)P2 levels after phospholipase C activation is therefore essential for a return to basal neuronal activity. However, the dynamics of phosphoinositide metabolism have not been analyzed in neurons. We measured dynamic changes of PI(4,5)P2, phosphatidylinositol 4-phosphate, diacylglycerol, inositol 1,4,5-trisphosphate...

Classification of embryo sacs in the Eragrostis curvula Complex

Directory of Open Access Journals (Sweden)

T. B. Vorster

1984-12-01

Full Text Available At each of 17 collecting points between Johannesburg and Brits in the Transvaal, three plants which belong to the  Eragrostis curvula Complex were collected and studied. A total o f 3 902 embryo sacs was examined in this sample. Of the embryo sacs examined, 3 306 were apomictic by means of diplospory, whereas 99 were sexual monosporic Polygonum-type embryo sacs. One hundred and nineteen embryo sacs were abnormal or divergent, and 378 were degenerated. There are indications that seasonal climatic fluctuations may be responsible for embryo sacs developing abnormally or degenerating. Simple and multiple correlations confirmed that sexual embryo sacs usually do not develop abnormally or degenerate during the later developmental stages. This finding lends credence to both the system of classification of individual embryo sacs and to the validity of the estimate of the proportion of sexuality of the plants sampled at each sampling point.

The PP2AB56 phosphatase promotes the association of Cdc20 with APC/C in mitosis.

Science.gov (United States)

Lee, Sun Joo; Rodriguez-Bravo, Veronica; Kim, Hyunjung; Datta, Sutirtha; Foley, Emily A

2017-05-15

PP2A comprising B56 regulatory subunit isoforms (PP2A B56 ) is a serine/threonine phosphatase essential for mitosis. At the kinetochore, PP2A B56 both stabilizes microtubule binding and promotes silencing of the spindle assembly checkpoint (SAC) through its association with the SAC protein BubR1. Cells depleted of the B56 regulatory subunits of PP2A are delayed in activation of Cdc20-containing APC/C (APC/C Cdc20 ), which is an essential step for mitotic exit. It has been hypothesized that this delay arises from increased production of the mitotic checkpoint complex (MCC), an APC/C Cdc20 inhibitor formed at unattached kinetochores through SAC signaling. In contrast to this prediction, we show that depletion of B56 subunits does not increase the amount or stability of the MCC. Rather, delays in APC/C Cdc20 activation in B56-depleted cells correlate with impaired Cdc20 binding to APC/C. Stimulation of APC/C Cdc20 assembly does not require binding between PP2A B56 and BubR1, and thus this contribution of PP2A B56 towards mitotic exit is distinct from its functions at kinetochores. PP2A B56 associates with APC/C constitutively in a BubR1-independent manner. A mitotic phosphorylation site on Cdc20, known to be a substrate of PP2A B56 , modulates APC/C Cdc20 assembly. These results elucidate the contributions of PP2A B56 towards completion of mitosis. © 2017. Published by The Company of Biologists Ltd.

Experimental Hyperactivity of the Endolymphatic Sac

DEFF Research Database (Denmark)

Friis, Morten; Thomsen, Allan Randrup; Poulsen, Steen Seier

2013-01-01

Injury to the endolymphatic sac may play an important role in the pathogenesis of Ménière's disease, an inner ear disorder characterized by hearing loss, tinnitus and attacks of vertigo. Isoimmunization of 16 inbred Lewis rats with a crude endolymphatic sac extract and complete Freund's adjuvant...

Tools for visualization of phosphoinositides in the cell nucleus

Czech Academy of Sciences Publication Activity Database

Kalasová, Ilona; Fáberová, Veronika; Kalendová, Alžběta; Uličná, Lívia; Yildirim, Sukriye; Venit, Tomáš; Hozák, Pavel

2016-01-01

Roč. 145, č. 4 (2016), s. 485-496 ISSN 0948-6143 R&D Projects: GA ČR GA16-03403S; GA ČR GAP305/11/2232; GA MŠk(CZ) ED1.1.00/02.0109; GA CR GA16-03403S Grant - others: Human Frontier Science Program(FR) RGP0017/2013 Institutional support: RVO:68378050 Keywords : Nucleus * Phosphoinositides * PI(4,5)P2 * PI(4)P Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.553, year: 2016

Interaction of Myosin Phosphatase Target Subunit (MYPT1) with Myosin Phosphatase-RhoA Interacting Protein (MRIP): A Role of Glutamic Acids in the Interaction.

Science.gov (United States)

Lee, Eunhee; Stafford, Walter F

2015-01-01

Scaffold proteins bind to and functionally link protein members of signaling pathways. Interaction of the scaffold proteins, myosin phosphatase target subunit (MYPT1) and myosin phosphatase-RhoA interacting protein (MRIP), causes co-localization of myosin phosphatase and RhoA to actomyosin. To examine biophysical properties of interaction of MYPT1 with MRIP, we employed analytical ultracentrifugation and surface plasmon resonance. In regard to MRIP, its residues 724-837 are sufficient for the MYPT1/MRIP interaction. Moreover, MRIP binds to MYPT1 as either a monomer or a dimer. With respect to MYPT1, its leucine repeat region, LR (residues 991-1030) is sufficient to account for the MYPT1/MRIP interaction. Furthermore, point mutations that replace glutamic acids 998-1000 within LR reduced the binding affinity toward MRIP. This suggests that the glutamic acids of MYPT1 play an important role in the interaction.

Legionella phosphatase hydrolyzes phosphatidylinositol 4,5-bisphosphate and inosital triphosphate in human neutrophils

International Nuclear Information System (INIS)

Dowling, J.N.; Saha, A.K.; Glew, R.H.

1987-01-01

Legionella are facultative intracellular bacterial pathogens which multiply in host phagocytes. L. micdadei cells contain an acid phosphatase (ACP) that blocks superoxide anion production by human neutrophils stimulated with the formylated peptide, fMLP. The possibility that ACP acts by interefering with polyphosphoinositide metabolism and the production of the intracellular second messenger, inositol triphosphate (IP 3 ) was explored. When neutrophil phosphoinositides were labeled with 32 P, incubation of the cells with ACP caused an 85% loss of the labeled phosphatidylinositol-4,5-bisphosphate (PIP 2 ) over 2 h. Treatment of [ 3 H]inositol-labeled neutrophils with ACP for 30 min resulted in a 20% decrease of labeled PIP 2 . Following fMLP stimulation, the fractional reduction in PIP 2 and the fractional increase in IP 3 was the same in ACP-treated and untreated neutrophils, but the total quantity of IP 3 was reduced by ACP pre-treatment. The reduction in IP 3 generated following fMLP stimulation seems to be due primarily to the decreased amount of PIP 2 available for hydrolysis. However, some loss of IP 3 due to direct hydrolysis by ACP cannot be ruled out. The Legionella phosphatase may compromise neutrophil response to the bacteria by hydrolyzing PIP 2 , the prognitor of IP 3 , and by hydrolyzing IP 3 itself

Cluster expansion of the wavefunction. Calculation of electron correlations in ground and excited states by SAC and SAC CI theories

International Nuclear Information System (INIS)

Nakatsuji, H.

1979-01-01

The SAC and SAC CI theories are formulated for actual calculations of singlet ground states and their excited states of arbitrary spin multiplicity. Approximations are considered for the variational methods since time-consuming terms are involved. The results of test calculations for singlet states have shown, with much smaller numbers of variables (sizes of the matrices involved), excellent agreement with the full CI and close-to-full CI results. This shows the utility of the SAC theory for ground states and especially of the SAC CI theory for excited states, since the slow convergence of the CI theory is much more critical for excited states than for ground states. (Auth.)

Gene expression of the endolymphatic sac

DEFF Research Database (Denmark)

Friis, Morten; Martin-Bertelsen, Tomas; Friis-Hansen, Lennart

2011-01-01

that the endolymphatic sac has multiple and diverse functions in the inner ear. Objectives:The objective of this study was to provide a comprehensive review of the genes expressed in the endolymphatic sac in the rat and perform a functional characterization based on measured mRNA abundance. Methods:Microarray technology...

Molecular cloning and chromosome mapping of the human gene encoding protein phosphotyrosyl phosphatase 1B

International Nuclear Information System (INIS)

Brown-Shimer, S.; Johnson, K.A.; Bruskin, A.; Green, N.R.; Hill, D.E.; Lawrence, J.B.; Johnson, C.

1990-01-01

The inactivation of growth suppressor genes appears to play a major role in the malignant process. To assess whether protein phosphotyrosyl phosphatases function as growth suppressors, the authors have isolated a cDNA clone encoding human protein phosphotyrosyl phosphatase 1B for structural and functional characterization. The translation product deduced from the 1,305-nucleotide open reading frame predicts a protein containing 435 amino acids and having a molecular mass of 49,966 Da. The amino-terminal 321 amino acids deduced from the cDNA sequence are identical to the empirically determined sequence of protein phosphotyrosyl phosphatase 1B. A genomic clone has been isolated and used in an in situ hybridization to banded metaphase chromosomes to determine that the gene encoding protein phosphotyrosyl phosphatase 1B maps as a single-copy gene to the long arm of chromosome 20 in the region q13.1-q13.2

Transvaginal ultrasound in threatened abortions with empty gestational sacs.

Science.gov (United States)

Tongsong, T; Wanapirak, C; Srisomboon, J; Sirichotiyakul, S; Polsrisuthikul, T; Pongsatha, S

1994-09-01

To determine whether transvaginal ultrasound criteria alone can distinguish viable from non-viable gestational sacs at a single examination. A prospective descriptive study was undertaken and analysis performed on 211 pregnancies complicated by threatened abortion and empty gestation sacs diagnosed by transvaginal ultrasound. The main outcome measure was the final diagnosis of viable or non-viable gestation on subsequent transvaginal sonography. The study shows that a single transvaginal ultrasound examination is useful in differentiating viable from non-viable gestation sacs. The mean sac diameter (MSD) was found to be the most useful criterion for determining non-viability. An MSD of > or = 17 mm that lacked an embryo and an MSD of > or = 13 mm without visible yolk sac were reliable predictors of non-viable gestation sacs at a single examination with 100% specificity and 100% positive predictive value. An MSD > or = 13 mm without visible yolk sac was the most sensitive criterion. Using MSD criteria, 73% of non-viable gestations could be reliably identified without any false-positive diagnoses. Deformed shape, low position and thin decidual reaction are strong indicators of non-viable gestations but are not 100% accurate. There is still a significant proportion of empty sacs, where no accurate distinction between viable and non-viable can be made according to one criterion at a single examination and in these cases serial examinations should be carried out before any active management is advocated. In most cases, transvaginal sonographic criteria alone can distinguish viable from non-viable empty gestational sacs at a single examination.

Regulation of the actin cytoskeleton-plasma membrane interplay by phosphoinositides.

Science.gov (United States)

Saarikangas, Juha; Zhao, Hongxia; Lappalainen, Pekka

2010-01-01

The plasma membrane and the underlying cortical actin cytoskeleton undergo continuous dynamic interplay that is responsible for many essential aspects of cell physiology. Polymerization of actin filaments against cellular membranes provides the force for a number of cellular processes such as migration, morphogenesis, and endocytosis. Plasma membrane phosphoinositides (especially phosphatidylinositol bis- and trisphosphates) play a central role in regulating the organization and dynamics of the actin cytoskeleton by acting as platforms for protein recruitment, by triggering signaling cascades, and by directly regulating the activities of actin-binding proteins. Furthermore, a number of actin-associated proteins, such as BAR domain proteins, are capable of directly deforming phosphoinositide-rich membranes to induce plasma membrane protrusions or invaginations. Recent studies have also provided evidence that the actin cytoskeleton-plasma membrane interactions are misregulated in a number of pathological conditions such as cancer and during pathogen invasion. Here, we summarize the wealth of knowledge on how the cortical actin cytoskeleton is regulated by phosphoinositides during various cell biological processes. We also discuss the mechanisms by which interplay between actin dynamics and certain membrane deforming proteins regulate the morphology of the plasma membrane.

Interplay between phosphoinositide lipids and calcium signals at the leading edge of chemotaxing ameboid cells☆

Science.gov (United States)

Falke, Joseph J.; Ziemba, Brian P.

2014-01-01

The chemotactic migration of eukaryotic ameboid cells up concentration gradients is among the most advanced forms of cellular behavior. Chemotaxis is controlled by a complex network of signaling proteins bound to specific lipids on the cytoplasmic surface of the plasma membrane at the front of the cell, or the leading edge. The central lipid players in this leading edge signaling pathway include the phosphoinositides PI(4,5)P2 (PIP2) and PI(3,4,5)P3 (PIP3), both of which play multiple roles. The products of PI(4,5)P2 hydrolysis, diacylglycerol (DAG) and Ins(1,4,5)P3 (IP3), are also implicated as important players. Together, these leading edge phosphoinositides and their degradation products, in concert with a local Ca2+ signal, control the recruitment and activities of many peripheral membrane proteins that are crucial to the leading edge signaling network. The present critical review summarizes the current molecular understanding of chemotactic signaling at the leading edge, including newly discovered roles of phosphoinositide lipids and Ca2+, while highlighting key questions for future research. PMID:24451847

Structural basis for inhibition of the protein tyrosine phosphatase 1B by phosphotyrosine peptide mimetics

NARCIS (Netherlands)

Groves, M R; Yao, Z J; Roller, P P; Burke, T R; Barford, D

1998-01-01

Protein tyrosine phosphatases regulate diverse cellular processes and represent important targets for therapeutic intervention in a number of diseases. The crystal structures of protein tyrosine phosphatase 1B (PTP1B) in complex with small molecule inhibitors based upon two classes of

Surveillance Analysis Computer System (SACS): Software requirements specification (SRS). Revision 2

International Nuclear Information System (INIS)

Glasscock, J.A.

1995-01-01

This document is the primary document establishing requirements for the Surveillance Analysis Computer System (SACS) database, an Impact Level 3Q system. SACS stores information on tank temperatures, surface levels, and interstitial liquid levels. This information is retrieved by the customer through a PC-based interface and is then available to a number of other software tools. The software requirements specification (SRS) describes the system requirements for the SACS Project, and follows the Standard Engineering Practices (WHC-CM-6-1), Software Practices (WHC-CM-3-10) and Quality Assurance (WHC-CM-4-2, QR 19.0) policies

Activation of Phosphoinositide Metabolism by Cholinergic Agents.

Science.gov (United States)

1992-03-15

most notably calcium. Cholinergic agonist-induced seizures; Brain second messenger systems; Neurotransmitter/ Neuromodulator interactions; RAV; Lab...have been described: modulation by protein kinase C and modulation by neurotransmitter (or neuromodulator ) interactions. Agents which stimulate...phosphoinositide hydrolysis that has been identified consists of interactions among neurotransmitter systems or neuromodulators . Perhaps those most widely

SAC-C mission, an example of international cooperation

Science.gov (United States)

Colomb, F.; Alonso, C.; Hofmann, C.; Nollmann, I.

In comp liance with the objectives established in the National Space Program, Argentina in Space 1997-2008 ((Plan Espacial Nacional, Argentina en el Espacio 1997-2008), the National Commission on Space Activities (Comisión Nacional de Actividades Espaciales - CONAE) undertook the design, construction, and launching of the SAC-C satellite in close collaboration with NASA. The purpose of this Mission is to carry out observations of interest both for the USA and Argentina, thus contributing effectively to NASA's Earth Science Program and to CONAE's National Space Program. The SAC-C is an international Earth observing satellite mission conceived as a partnership between CONAE and NASA, with additional support in instrumentation and satellite development from the Danish DSRI, the Italian ASI, the French CNES and the Brazilian INPE. A Delta II rocket successfully launched it on November 21st, 2000, from Vandenberg AFB, California, USA. Ten instruments on board the SAC-C perform different studies related to the ground and sea ecosystems, the atmosphere and the geomagnetic field. There are also technological experiments for determination of the satellite attitude and velocity as well as for the studies of the influence of space radiation on advanced electronic components . The inclusion of SAC-C in the AM Constellation, jointly with NASA satellites Landsat 7, EO 1 and Terra, is another example of important international cooperation which synergies the output of any single Mission. The Constellation has been working since March 2001 as a single mission and several cooperative activities have been undertaken including several jointly sponsored technical workshops and collaborative spacecraft navigation experiments. A flight campaign of the NASA AVIRIS instrument was performed in Argentine during January and February 2001, for calibration of SAC-C and EO 1 cameras and the development of joint scientific works. In Cordoba Space Center a jointly operated ground GPS reference

Study on initial stage of diesel spray formation. Effects of the condition inside the nozzle sac; Diesel funmu no shoki keisei katei ni kansuru kenkyu. Sac nai nenryo no eikyo

Energy Technology Data Exchange (ETDEWEB)

Ishikawa, N.; Tsujimura, K. [Nissan Diesel Motor Co. Ltd., Saitama (Japan); Komori, M.

1996-06-25

To realize clean diesel exhaust, it is very important to clarify the atomization phenomena of the fuel spray. In this study, the initial stage of the atomization process of a diesel injection fuel spray was analyzed with a high-speed image converter camera under the conditions of atmospheric gas pressure and room temperature. As a result, it was found that the initial spray formation was greatly affected lay the condition inside the nozzle sac. In the case in which fuel existed in the sac, pin-like structure spray formation was observed at the initial injection stage. This phenomenon was not observed in the case in which no fuel was present in the sac, and a widely spread fuel spray formation was observed at the initial injection stage. The relatively low-speed fuel spray injected in the initial low-sac-pressure condition was pushed away by the subsequent fuel spray injected in the high-sac-pressure condition. 7 refs., 12 figs., 1 tab.

Normal measurement of spinal cord and dural sac by CT myelography

International Nuclear Information System (INIS)

Yun, Ku Sub; Choi, Yo Won; Han, Moon Hee; Chang, Kee Hyun

1988-01-01

The data on the normal measurement of spinal cord are essential for an objective assessment of equivocal change of spinal cord size in the various clinical settings. The present study was therefore undertaken to evaluate normal range of spinal cord dimensions in Koreas. CT myelography of the cervical and thoracic region was performed in 60 patients who had symptoms referable to lumbosacral region and then computed tomographic measurement of spinal cord and dural sac was performed. The results are as follows: 1. The anteroposterior diameter of spinal cord was maximum at C1 level (8.6±1.4mm) and minimum at T6 level (6.4±1.7mm). 2. The transverse diameter of spinal cord was maximum at C4 and C5 levels (13.3±1.6mm) and minimum at T8 (8.1±1.9mm) and T10 (8.1±1.3mm) levels. 3. The area of spinal cord was maximum at C5 level (76±16mm 2 ) and minimum at T6 (40±24mm 2 ) and T8 (40±23mm 2 ) levels. 4. The ratio of anteroposterior diameter/transverse diameter of spinal cord was smallest at C4 (0.57±0.11) and C5 (0.57±0.09) levels and largest at T12 (0.9±0.17) level. 5. The ratio of anteroposterior diameter of spinal cord/dural sac was maximum at C4 level (0.73±0.14) and minimum at T12 level (0.52±0.15). The ratio of transverse diameter of spinal cord/dural sac was maximum at C3 (0.66±0.10) and C4 (0.66±0.14) levels and minimum at T12 level (0.46±0.18). The ratio of area of spinal cord/dural sac was maximum at C3 level (0.48±0.13) and minimum at T12 level (0.29±0.20). 6. The location of cervical cord in dural sac was mainly ventral (56%) at C1 level, middle (40-73%) from C2 to C6 level and dorsal (44%) at C7 level. The location of thoracic cord in dural sac was chiefly middle (61%) at T2 level and lower thoracic level (T10: 60% and T12: 51%) and mainly ventral (59-84%) at other levels.

The Sac Actun System, Quintana Roo, Mexico

International Nuclear Information System (INIS)

Kambesis, P. N.; Coke, J. G.

2016-01-01

The Sac Actun system, located in northeast Quintana Roo, Mexico, is among the most extensive underwater cave systems located along the Caribbean coast of the Yucatan Peninsula. The cave is composed of linear phreatic conduits that have two forms. The coastal sections of the Sac Actun system are characterized by low horizontal tunnels that form mazes paralleling the coast and rudimentary conduits broken by fracture-controlled rooms. Inland passages are fault/fracture controlled, have a linear, anastomotic configuration, and align perpendicular to the coast. Access to the cave system is gained through cenotes which are the portals into the Yucatan underwater cave systems. The occurrence of drowned speleothems in many parts of the cave system, and sections of air-filled upper level passages are indicative of major fluctuations in sea level. The Sac Actun system is part of one of the most extensive and significant eogenetic karst aquifers in the world. The development of the Sac Actun system, as well as the many other caves systems along the Yucatan Caribbean Coast is controlled by the coastal hydrologic regime, driven by glacio-eustatics, and influenced by stratigraphic and structural controls. The karstic permeability of the aquifer makes it and the Sac Actun system vulnerable to the anthropogenic impacts of increased population growth, quarries, and infrastructure development associated with the burgeoning tourist industry that dominates land use in the region. (Author)

Interplay between phosphoinositide lipids and calcium signals at the leading edge of chemotaxing ameboid cells.

Science.gov (United States)

Falke, Joseph J; Ziemba, Brian P

2014-09-01

The chemotactic migration of eukaryotic ameboid cells up concentration gradients is among the most advanced forms of cellular behavior. Chemotaxis is controlled by a complex network of signaling proteins bound to specific lipids on the cytoplasmic surface of the plasma membrane at the front of the cell, or the leading edge. The central lipid players in this leading edge signaling pathway include the phosphoinositides PI(4,5)P2 (PIP2) and PI(3,4,5)P3 (PIP3), both of which play multiple roles. The products of PI(4,5)P2 hydrolysis, diacylglycerol (DAG) and Ins(1,4,5)P3 (IP3), are also implicated as important players. Together, these leading edge phosphoinositides and their degradation products, in concert with a local Ca(2+) signal, control the recruitment and activities of many peripheral membrane proteins that are crucial to the leading edge signaling network. The present critical review summarizes the current molecular understanding of chemotactic signaling at the leading edge, including newly discovered roles of phosphoinositide lipids and Ca(2+), while highlighting key questions for future research. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Phosphoinositides: Tiny Lipids With Giant Impact on Cell Regulation

Science.gov (United States)

2013-01-01

Phosphoinositides (PIs) make up only a small fraction of cellular phospholipids, yet they control almost all aspects of a cell's life and death. These lipids gained tremendous research interest as plasma membrane signaling molecules when discovered in the 1970s and 1980s. Research in the last 15 years has added a wide range of biological processes regulated by PIs, turning these lipids into one of the most universal signaling entities in eukaryotic cells. PIs control organelle biology by regulating vesicular trafficking, but they also modulate lipid distribution and metabolism via their close relationship with lipid transfer proteins. PIs regulate ion channels, pumps, and transporters and control both endocytic and exocytic processes. The nuclear phosphoinositides have grown from being an epiphenomenon to a research area of its own. As expected from such pleiotropic regulators, derangements of phosphoinositide metabolism are responsible for a number of human diseases ranging from rare genetic disorders to the most common ones such as cancer, obesity, and diabetes. Moreover, it is increasingly evident that a number of infectious agents hijack the PI regulatory systems of host cells for their intracellular movements, replication, and assembly. As a result, PI converting enzymes began to be noticed by pharmaceutical companies as potential therapeutic targets. This review is an attempt to give an overview of this enormous research field focusing on major developments in diverse areas of basic science linked to cellular physiology and disease. PMID:23899561

Functional blood flow patterns of the endolymphatic sac in the rat

DEFF Research Database (Denmark)

Friis, Morten; Qvortrup, Klaus

2008-01-01

Conclusion. Visualization of the endolymphatic sac vascular network under video fluorescence microscopy showed a typical microvascular organization. The microvascular arrangement and the microcirculation may reflect a functional state of the endolymphatic sac. Damage or change of the blood circul...... sac served as return paths for the microcirculation. The blood flow pattern was highly variable between rats.......Conclusion. Visualization of the endolymphatic sac vascular network under video fluorescence microscopy showed a typical microvascular organization. The microvascular arrangement and the microcirculation may reflect a functional state of the endolymphatic sac. Damage or change of the blood...

Phosphatase activity of Poa pratensis seeds. I. Preliminary studies on acid phosphatase II

Directory of Open Access Journals (Sweden)

I. Lorenc-Kubis

2015-01-01

Full Text Available Acid phosphatase (EC 3.1.3.2 was extracted with 0.1 M sodium acetate buffer pH 5.1 from Poa pratensis seeds, and separated into three fractions by chromatography on DEAE cellulose. The highest activity was found in fraction Il-b (acid phosphatase II. The activity of the enzyme was optimal at pH 4.9. It hydrolyzed p-nitrophenyl phosphate most readily among the various phosphomonoesters examined. Acid phosphatase II showed also a high activity toward β-naphtyl phosphate and phenyl phosphate, very low activity towards β-glycero phosphate, 5'-GMP and no activity with glucose-1 phosphate. The enzyme was inhibited by Ca2+ and fluoride, but activated by Mg2+. EDTA had no influence on the activity of the enzyme.

Phosphatase activity of Poa pratensis seeds. l. Preliminary studies on acid phosphatase II

Energy Technology Data Exchange (ETDEWEB)

Lorenc-Kubis, I.; Morawiecka, B.

1973-01-01

Acid phosphatase (EC 3.1.3.2) was extracted from 0.1 M sodium acetate buffer, pH 5.1 from Poa pratensis seeds, and separated into three fractions by chromatography on DEAE cellulose. The highest activity was found in fraction II-b (acid phosphatase II). The activity of the enzyme was optimal at pH 4.9. It hydrolyzed p-nitrophenyl phosphate most readily among the various phosphomonoesters examined. Acid phosphatase II showed also a high activity toward ..beta..-naphtyl phosphate and phenyl phosphate, very low activity towards ..beta..-glycero phosphate, 5'-GMP and no activity with glucose-1 phosphate. The enzyme was inhibited by Ca/sup 2 +/ and fluoride, but activated by Mg/sup 2 +/. EDTA had no influence on the activity of the enzyme. 12 references, 3 figures, 4 tables.

The Association of Endothelin-1 Signaling with Bone Alkaline Phosphatase Expression and Protumorigenic Activities in Canine Osteosarcoma.

Science.gov (United States)

Neumann, Z L; Pondenis, H C; Masyr, A; Byrum, M L; Wycislo, K L; Fan, T M

2015-01-01

Canine osteosarcoma (OS) is an aggressive sarcoma characterized by pathologic skeletal resorption and pulmonary metastases. A number of negative prognostic factors, including bone alkaline phosphatase, have been identified in dogs with OS, but the underlying biologic factors responsible for such observations have not been thoroughly investigated. Endothelin-1-mediated signaling is active during bone repair, and is responsible for osteoblast migration, survival, proliferation, and bone alkaline phosphatase expression. The endothelin-1 signaling axis is active in canine OS cells, and this pathway is utilized by malignant osteoblasts for promoting cellular migration, survival, proliferation, and bone alkaline phosphatase activities. 45 dogs with appendicular OS. The expressions of endothelin-1 and endothelin A receptor were studied in OS cell lines and in samples from spontaneously occurring tumors. Activities mediated by endothelin-1 signaling were investigated by characterizing responses in 3 OS cell lines. In 45 dogs with OS, bone alkaline phosphatase concentrations were correlated with primary tumor osteoproductivity. Canine OS cells express endothelin-1 and endothelin A receptor, and this signaling axis mediates OS migration, survival, proliferation, and bone alkaline phosphatase activities. In OS-bearing dogs, circulating bone alkaline phosphatase activities were positively correlated with primary tumor relative bone mineral densities. Canine OS cells express endothelin-1 and functional endothelin A receptors, with the potential for a protumorigenic signaling loop. Increases in bone alkaline phosphatase activity are associated with osteoblastic OS lesions, and might be an epiphenomenon of active endothelin-1 signaling or excessive osteoproduction within the localized bone microenvironment. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Benign mixed tumor of the lacrimal sac

Directory of Open Access Journals (Sweden)

Jong-Suk Lee

2015-01-01

Full Text Available Neoplasms of the lacrimal drainage system are uncommon, but potentially life-threatening and are often difficult to diagnose. Among primary lacrimal sac tumors, benign mixed tumors are extremely rare. Histologically, benign mixed tumors have been classified as a type of benign epithelial tumor. Here we report a case of benign mixed tumor of the lacrimal sac.

Anxious moments for the protein tyrosine phosphatase PTP1B

OpenAIRE

Krishnan, Navasona; Tonks, Nicholas K.

2015-01-01

Chronic stress can lead to the development of anxiety and mood disorders. Thus, novel therapies for preventing adverse effects of stress are vitally important. Recently, the protein tyrosine phosphatase PTP1B was identified as a novel regulator of stress-induced anxiety. This opens up exciting opportunities to exploit PTP1B inhibitors as anxiolytics.

Efficiency of lachrymal sac drainage in newborns with dacryocystocele

Directory of Open Access Journals (Sweden)

Sakovich V.N.

2016-12-01

Full Text Available The article represents results of treatment of 14 newborns with unilateral dacryocystocele. Patients age was 7.2±0.5 days. In 9 newborns (64.3% dacryocystocele was complicated with lachrymal sac phlegmon; in 5 children (35.7% any complications were absent. Drainage of lachrymal sac through the lower lachrymal canaliculus, instillation of antibiotics, systemic antibiotic therapy in case of phlegmon were performed in all the children. Lachrymal sac washing was performed with a solution of the antibiotic ofloxacin till clear fluid evacuation. If necessary the drainage was repeated in 10 days. The drainage of lachrymal sac was successful in all the patients. 2-3 weeks after the drainage probing of nasolachrymal duct was perfomed in 4 children (28.6% including those 3 with lacrymal sac phlegmon. In 71.4% regression of dacryocystocele occurred itself. Any complications and side effects were not observed. Positive effect of the drainage, according to the authors, can be explained so that dilatation of lachrymal canaliculus before the procedure allows to eliminate Rosenmьller valve stenosis and evacuation of fluid, mucus and pus, being breeding ground for microorganisms from lachrymal sac, promotes inflammation subsiding. Authors also recommend to pay attention on prenatal diagnosis of dacryocystocele, using ultrasound investigation in the 3rd trimester of pregnancy.

Gene Expression in the Human Endolymphatic Sac

DEFF Research Database (Denmark)

Møller, Martin Nue; Kirkeby, Svend; Vikeså, Jonas

2015-01-01

a1 sodium-bicarbonate transporter, SLC9a2 sodium-hydrogen transporter, SLC12a3 thiazide-sensitive Na-Cl transporter, and SLC34a2 sodium-phosphate transporter. CONCLUSIONS: Several important ion transporters of the SLC family are expressed in the human endolymphatic sac, including Pendrin...

Acute Respiratory Distress Syndrome Neutrophils Have a Distinct Phenotype and Are Resistant to Phosphoinositide 3-Kinase Inhibition.

Science.gov (United States)

Juss, Jatinder K; House, David; Amour, Augustin; Begg, Malcolm; Herre, Jurgen; Storisteanu, Daniel M L; Hoenderdos, Kim; Bradley, Glyn; Lennon, Mark; Summers, Charlotte; Hessel, Edith M; Condliffe, Alison; Chilvers, Edwin R

2016-10-15

Acute respiratory distress syndrome is refractory to pharmacological intervention. Inappropriate activation of alveolar neutrophils is believed to underpin this disease's complex pathophysiology, yet these cells have been little studied. To examine the functional and transcriptional profiles of patient blood and alveolar neutrophils compared with healthy volunteer cells, and to define their sensitivity to phosphoinositide 3-kinase inhibition. Twenty-three ventilated patients underwent bronchoalveolar lavage. Alveolar and blood neutrophil apoptosis, phagocytosis, and adhesion molecules were quantified by flow cytometry, and oxidase responses were quantified by chemiluminescence. Cytokine and transcriptional profiling were used in multiplex and GeneChip arrays. Patient blood and alveolar neutrophils were distinct from healthy circulating cells, with increased CD11b and reduced CD62L expression, delayed constitutive apoptosis, and primed oxidase responses. Incubating control cells with disease bronchoalveolar lavage recapitulated the aberrant functional phenotype, and this could be reversed by phosphoinositide 3-kinase inhibitors. In contrast, the prosurvival phenotype of patient cells was resistant to phosphoinositide 3-kinase inhibition. RNA transcriptomic analysis revealed modified immune, cytoskeletal, and cell death pathways in patient cells, aligning closely to sepsis and burns datasets but not to phosphoinositide 3-kinase signatures. Acute respiratory distress syndrome blood and alveolar neutrophils display a distinct primed prosurvival profile and transcriptional signature. The enhanced respiratory burst was phosphoinositide 3-kinase-dependent but delayed apoptosis and the altered transcriptional profile were not. These unexpected findings cast doubt over the utility of phosphoinositide 3-kinase inhibition in acute respiratory distress syndrome and highlight the importance of evaluating novel therapeutic strategies in patient-derived cells.

Selective Intra-procedural AAA sac Embolization During EVAR Reduces the Rate of Type II Endoleak.

Science.gov (United States)

Mascoli, C; Freyrie, A; Gargiulo, M; Gallitto, E; Pini, R; Faggioli, G; Serra, C; De Molo, C; Stella, A

2016-05-01

The pre-treatment presence of at least six efferent patent vessels (EPV) from the AAA sac and/or AAA thrombus volume ratio (VR%) AAA sac embolization (Group A, 2012-2013) were retrospectively selected and compared with a control group of patients with the same p-MRF, who underwent EVAR without intra-procedural sac embolization (Group B, 2008-2010). The presence of ELIIp was evaluated by duplex ultrasound at 0 and 6 months, and by contrast enhanced ultrasound at 12 months. The association between AAA diameter, age, COPD, smoking, anticoagulant therapy, and AAA sac embolization with ELIIp was evaluated using multiple logistic regression. The primary endpoint was the effectiveness of the intra-procedural AAA sac embolization for ELIIp prevention. Secondary endpoints were AAA sac evolution and freedom from ELIIp and embolization related re-interventions at 6-12 months. Seventy patients were analyzed: 26 Group A and 44 Group B; the groups were homogeneous for clinical/morphological characteristics. In Group A the median number of coils positioned in AAA sac was 4.1 (IQR 1). There were no complications related to the embolization procedures. A significantly lower number of ELIIp was detected in Group A than in Group B (8/26 vs. 33/44, respectively, p AAA sac embolization was the only factor independently associated with freedom from ELIIp at 6 (OR 0.196, 95% CI 0.06-0.63; p = .007) and 12 months (OR 0.098, 95% CI 0.02-0.35; p AAA sac diameter shrinkage were detected between the two groups at 6-12 months (p = .42 and p = .58, respectively). Freedom from ELIIp related and embolization related re-interventions was 100% in both groups, at 6 and 12 months. Selective intra-procedural AAA sac embolization in patients with p-MRF is safe and could be an effective method to reduce ELIIp. Further studies are mandatory to support these results at long-term follow up. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Phosphoinositide metabolism and adrenergic receptors in astrocytes

International Nuclear Information System (INIS)

Noble, E.P.; Ritchie, T.; de Vellis, J.

1986-01-01

Agonist-induced phosphoinositide (PI) breakdown functions as a signal generating system. Diacylglycerol, one breakdown product of phosphotidylinositol-4,5-diphosphate hydrolysis, can stimulate protein kinase C, whereas inositol triphosphate, the other product, has been proposed to be a second messenger for Ca ++ mobilization. Using purified astrocyte cultures from neonatal rat brain, the effects of adrenergic agonists and antagonists at 10 -5 M were measured on PI breakdown. Astrocytes grown in culture were prelabeled with ( 3 H)inositol, and basal ( 3 H) inositol phosphate (IP 1 ) accumulation was measured in the presence of Li + . Epinephrine > norepinephrine (NE) were the most active stimulants of IP 1 production. The α 1 adrenoreceptor blockers, phentolamine and phenoxybenzamine, added alone had no effect on IP 1 production was reduced below basal levels. Propranolol partially blocked the effects of NE. Clonidine and isoproterenol, separately added, reduced IP 1 below basal levels and when added together diminished IP 1 accumulation even further. The role of adrenergic stimulation in the production of c-AMP

Fourier Imaging X-ray Spectrometer (FIXS) for the Argentinian, Scout-launched satelite de Aplicaciones Cienficas-1 (SAC-1)

International Nuclear Information System (INIS)

Dennis, B.R.; Crannell, C.J.; Desai, U.D.

1988-01-01

The Fourier Imaging X-ray Spectrometer (FIXS) is one of four instruments on SAC-1, the Argentinian satellite being proposed for launch by NASA on a Scout rocket in 1992/3. The FIXS is designed to provide solar flare images at X-ray energies between 5 and 35 keV. Observations will be made on arcsecond size scales and subsecond time scales of the processes that modify the electron spectrum and the thermal distribution in flaring magnetic structures

Cofilin is a pH sensor for actin free barbed end formation: role of phosphoinositide binding.

Science.gov (United States)

Frantz, Christian; Barreiro, Gabriela; Dominguez, Laura; Chen, Xiaoming; Eddy, Robert; Condeelis, John; Kelly, Mark J S; Jacobson, Matthew P; Barber, Diane L

2008-12-01

Newly generated actin free barbed ends at the front of motile cells provide sites for actin filament assembly driving membrane protrusion. Growth factors induce a rapid biphasic increase in actin free barbed ends, and we found both phases absent in fibroblasts lacking H(+) efflux by the Na-H exchanger NHE1. The first phase is restored by expression of mutant cofilin-H133A but not unphosphorylated cofilin-S3A. Constant pH molecular dynamics simulations and nuclear magnetic resonance (NMR) reveal pH-sensitive structural changes in the cofilin C-terminal filamentous actin binding site dependent on His133. However, cofilin-H133A retains pH-sensitive changes in NMR spectra and severing activity in vitro, which suggests that it has a more complex behavior in cells. Cofilin activity is inhibited by phosphoinositide binding, and we found that phosphoinositide binding is pH-dependent for wild-type cofilin, with decreased binding at a higher pH. In contrast, phosphoinositide binding by cofilin-H133A is attenuated and pH insensitive. These data suggest a molecular mechanism whereby cofilin acts as a pH sensor to mediate a pH-dependent actin filament dynamics.

An inguinal hernia sac tumor of extrahepatic cholangiocarcinoma origin

Directory of Open Access Journals (Sweden)

Yamazaki Hidehiro

2006-03-01

Full Text Available Abstract Background Metastatic hernia sac tumor from biliary malignancy is extremely rare with only one such case previously reported. We herein report an additional case of extrahepatic cholangiocarcinoma presenting as a hernia sac tumor. Case presentation A 78-year-old man presented with an irreducible right inguinal hernia associated with a firm tumor, 2.0 cm in diameter. A computed tomography scan demonstrated a soft tissue density mass with heterogeneous enhancement within the right inguinal canal. The patient underwent a hernia repair and the hernia sac tumor was resected. Histological examination of the tumor revealed a metastatic adenocarcinoma suggesting the tumor was of pancreato-biliary origin. Further investigation using imaging studies disclosed a primary tumor in the upper bile duct. The patient died of the disease nine months after the resection. Conclusion Hernia sac tumors should be considered when an irreducible, growing mass appears within an inguinal hernia. Computed tomography may be useful for the early detection of hernia sac tumors from undiagnosed intra-abdominal malignancies.

Aquarius and the Aquarius/SAC-D Mission

Science.gov (United States)

LeVine, D. M.; Lagerloef, G. S. E.; Torrusio, S.

2010-01-01

Aquarius is a combination L-band radiometer and scatterometer designed to map the salinity field at the ocean surface from space. It will be flown on the Aquarius/SAC-D mission, a partnership between the USA space agency (NASA) and Argentine space agency (CONAE). The mission is composed of two parts: (a) The Aquarius instrument being developed as part of NASA.s Earth System Science Pathfinder (ESSP) program; and (b) SAC-D the fourth spacecraft service platform in the CONAE Satellite de Aplicaciones Cientificas (SAC) program. The primary focus of the mission is to monitor the seasonal and interannual variations of the salinity field in the open ocean. The mission also meets the needs of the Argentine space program for monitoring the environment and for hazard detection and includes several instruments related to these goals.

A pigeon crop sac radioreceptor assay for prolactin

International Nuclear Information System (INIS)

Forsyth, I.A.; Buntin, J.D.; Nicoll, C.S.

1978-01-01

Ovine prolactin, labelled with 125 I by either lactoperoxidase or a mild chloramine T method, was bound to receptors from the pigeon crop sac mucosa cells of prolactin-injected pigeons. Binding was demonstrated in a crude homogenate of mucosal cells removed from the crop by scraping and in a subcellular fraction in which 5'- nucleotidase activity was enhanced two- to three-fold. The binding was specific, dependent on time, temperature and the concentration of receptors and had a dissociation constant of 7 x 10 -10 mol/l. The binding capacity of the crop tissue was 71 fmol/mg membrane protein. Nine purified preparations of prolactin from four species were assayed by local pigeon crop sac bioassay and by radioreceptor assay. The two methods were highly correlated (r = 0.934). The regression equation was radioreceptor assay = 1.22 bioassay - 0.18 indicating a 1:1 correspondence between the two methods for prolactin purified from sheep, rat, horse and pig anterior pituitary glands. (author)

and alanine (EC. 2.6.1.2) transaminases, and alkaline phosphatase

African Journals Online (AJOL)

The activities of aspartate (E.C. 2.6.1.1) and alanine (E.C. 2.6.1.2) transaminases (AST and ALT, respectively), and alkaline phosphatase (ALP) (E.C. 3.1.3.1) were determined in erythrocytes obtained from 20 HbAA, 15 HbAS and 12 HbSS human subjects. The results showed that the three enzymes had different levels of ...

Clinical significance of determination of SAC/PRA value in patients with primary aldosteronism

International Nuclear Information System (INIS)

Li Liren; Dai Yaozong; Liu Jiumin

2003-01-01

Objective: To investigate the diagnostic significance of determining SAC/PRA valve in hyperaldosteronism. Methods: Plasma renin activity (PRA) and angiotensin (AT-II) as well as serum aldosterone contents were measured with RIA in 48 patients with primary aldosteronism and 30 controls. The SAC/PRA value was calculated. Results: Contents of PRA, AT-II and Aldo in blood of patients with primary aldosteronism were very significantly different from those in controls (p < 0.001) (PRA 0.14 ± 0.08 ng/ml/h vs 0.57 ± 0.08 ng/ml/h; AT-II 21.21 ± 7.55 ng/L vs 36.03 ± 6.11 ng/L; Aldo 1.07 ± 0.34 nmol/L vs 0.33 ± 0.04 nmol/L). Calculated SAC/PRA value was 913 ± 409 (normal upper limit 400). Conclusion: SAC/PRA value is an useful accessory diagnostic criterion for primary aldosteronism

Surveillance Analysis Computer System (SACS) software requirements specification (SRS)

International Nuclear Information System (INIS)

Glasscock, J.A.; Flanagan, M.J.

1995-09-01

This document is the primary document establishing requirements for the Surveillance Analysis Computer System (SACS) Database, an Impact Level 3Q system. The purpose is to provide the customer and the performing organization with the requirements for the SACS Project

Intra-gestational sac injection for tubal pregnancy: an interventional approach

International Nuclear Information System (INIS)

Wang Yitang; Sun Xiaobo; Xu Xiaojun; Zhang Feiyue; Wu Ke; Song Yingxin; Han Mingjun

2002-01-01

Objective: It's an investigation of the procedure, effects and clinical application of the interventional intra-gestational sac injection as a treatment of tubal pregnancy. Methods: Under DSA guidance a selective salpingography was performed and MTX was injected into the gestational sac or oviduct. The procedure was performed in 13 cases with oviductal pregnancy before the gestational sac ruptured. Results: Technical success was obtained in all cases. The serum HCG began to fall in 7 days after the procedure, and dropped to normal level in 2-4 weeks of the procedure. Conclusion: Interventional selective salpingography and intra-gestational sac injection is a simple, safe and effective treatment of the un-ruptured tubal pregnancy

Characterization of cholinergic muscarinic receptor-stimulated phosphoinositide metabolism in brain from immature rats

International Nuclear Information System (INIS)

Balduini, W.; Murphy, S.D.; Costa, L.G.

1990-01-01

Hydrolysis of phosphoinositides elicited by stimulation of cholinergic muscarinic receptors has been studied in brain from neonatal (7-day-old) rats in order to determine: (1) whether the neonatal rat could provide a good model system to study this signal-transduction pathway; and (2) whether potential differences with adult nerve tissue would explain the differential, age-related effects of cholinergic agonists. Accumulation of [3H] inositol phosphates in [3H]inositol prelabeled slices from neonatal and adult rats was measured as an index of phosphoinositide metabolism. Full (acetylcholine, methacholine, carbachol) and partial (oxotremorine, bethanechol) agonists had qualitatively similar, albeit quantitatively different, effects in neonatal and adult rats. Atropine and pirenzepine effectively blocked the carbachol-induced response with inhibition constants of 1.2 and 20.7 nM, respectively. In all brain areas, response to all agonists was higher in neonatal than adult rats, and in hippocampus and cerebral cortex the response was higher than in cerebellum or brainstem. The relative intrinsic activity of partial agonists was higher in the latter two areas (0.6-0.7) than in the former two (0.3-0.4). Carbachol-stimulated phosphoinositide metabolism in brain areas correlated well with the binding of [3H]QNB (r2 = 0.627) and, particularly, with [3H]pirenzepine (r2 = 0.911). In cerebral cortex the effect of carbachol was additive to that of norepinephrine and glutamate. The presence of calcium (250-500 microM) was necessary for maximal response to carbachol to be elicited; the EC50 value for Ca2+ was 65.4 microM. Addition of EDTA completely abolished the response. Removal of sodium ions from the incubation medium reduced the response to carbachol by 50%

The Fourier Imaging X-ray Spectrometer (FIXS) for the Argentinian, Scout-launched satelite de Aplicaciones Cienficas-1 (SAC-1)

Science.gov (United States)

Dennis, Brian R.; Crannell, Carol JO; Desai, Upendra D.; Orwig, Larry E.; Kiplinger, Alan L.; Schwartz, Richard A.; Hurford, Gordon J.; Emslie, A. Gordon; Machado, Marcos; Wood, Kent

1988-01-01

The Fourier Imaging X-ray Spectrometer (FIXS) is one of four instruments on SAC-1, the Argentinian satellite being proposed for launch by NASA on a Scout rocket in 1992/3. The FIXS is designed to provide solar flare images at X-ray energies between 5 and 35 keV. Observations will be made on arcsecond size scales and subsecond time scales of the processes that modify the electron spectrum and the thermal distribution in flaring magnetic structures.

SAC-C Mission and the Morning Constellation

Science.gov (United States)

Colomb, F. R.; Alonso, C.; Hofmann, C.; Frulla, L.; Nollmann, I.; Milovich, J.; Kuba, J.; Ares, F.; Kalemkarian, M.

2002-01-01

components (ICARE), provided by CNES will permit improvement of risk estimation models for radiation effect on last generation integrated circuit technology. . On June 14th, 2000 CONAE and NASA signed an amendment to the Memorandum of Understanding for the SAC-C mission in order that the SAC-C satellite, were included in a constellation - named "Morning Constellation". It is integrated by USA satellites Landsat 7, EO 1, Terra, and Argentine SAC-C that feature on-board instruments from the United States, Argentina, Denmark, Italy, France, and Japan. The four satellite tracks on the Earth's surface are the same, their orbital height being 705 km and their inclination, 98.21 degrees. They cross the Equator at 10:00, 10:01, 10:15, and 10:30 hours, respectively (local time). Satellites comply with the World Wide Reference System. The Constellation has been working since March 2001 as a single mission and several cooperative activities have been undertaken and will be presented in this paper. Several jointly sponsored technical workshops have been held, and also collaborative spacecraft navigation experiments have been made. One of the objectives of the AM Constellation is the collaboration in the case of emergencies, NASA and CONAE agreed to give preference in those situation in the planification of their satellite acquisitions. From all the possible hazardous events, the most important for the country are fire and floods. In relation to fires, CONAE is presently adapting and developing the algorithms for using MODIS data to generate a fire map product. Additionally research on fire detection is carried out using the data from the HSTC camera. In relation to flooding, CONAE works in cooperation to national institutions providing the data and, in some cases, producing flood extent maps. In particular MMRS data is demonstrating to be very effective due to its spectral and radiometric resolutions, and its large swath which is well suited for extended countries like Argentina.

Research on Phosphatases of Belladona Leaves and Their Purification (Part 1

Directory of Open Access Journals (Sweden)

M. Khorsand

1956-12-01

Full Text Available Belladona leaves as well as all other studied leaves contains two distinct phosphatase fractions belonging respectively to types II and IIIi the major parts of these enzymes is extraetible by water. It was not possible to extract the non soluble fraction which is solidly retained by the cellular constituents. Phosphatase II does not differ from other phosphatnses of the same type. Whereas phosphatase III is distinetely different from enzymes of the same type of vegetal or animal origins. It is activated by bivalent metallic ions which are specific activators of the alkaline phcspbatnses: Mg-Zn-Ni and Co.

Presentations for the 1st muon science experimental facility advisory committee meeting (MuSAC)

International Nuclear Information System (INIS)

2003-03-01

The J-PARC Muon Science Advisory Committee, so called 'MuSAC', is organized under the J-PARC Project Director during construction period, in order to discuss the following items related to the Muon Science Facility at J-PARC and to report to the Project Director and Muon Science Facility construction team. The committee will review and advise the following subjects: 1) Project definition of the experimental facility to be constructed in Materials and Life Science Facility of J-PARC, 2) Content of the 1st phase experimental program. This issue is the collection of the documents presented at the title meeting. (J.P.N.)

Protein Phosphatase 1 Recruitment by Rif1 Regulates DNA Replication Origin Firing by Counteracting DDK Activity

Directory of Open Access Journals (Sweden)

Anoushka Davé

2014-04-01

Full Text Available The firing of eukaryotic origins of DNA replication requires CDK and DDK kinase activities. DDK, in particular, is involved in setting the temporal program of origin activation, a conserved feature of eukaryotes. Rif1, originally identified as a telomeric protein, was recently implicated in specifying replication timing in yeast and mammals. We show that this function of Rif1 depends on its interaction with PP1 phosphatases. Mutations of two PP1 docking motifs in Rif1 lead to early replication of telomeres in budding yeast and misregulation of origin firing in fission yeast. Several lines of evidence indicate that Rif1/PP1 counteract DDK activity on the replicative MCM helicase. Our data suggest that the PP1/Rif1 interaction is downregulated by the phosphorylation of Rif1, most likely by CDK/DDK. These findings elucidate the mechanism of action of Rif1 in the control of DNA replication and demonstrate a role of PP1 phosphatases in the regulation of origin firing.

The endolymphatic sac, a potential endocrine gland?

DEFF Research Database (Denmark)

Qvortrup, K; Rostgaard, J; Holstein-Rathlou, N H

1999-01-01

A previous investigation indicated that the chief cells of the endolymphatic sac produce an endogenous inhibitor of sodium re-absorption in the kidneys, which has tentatively been named "saccin". In this study, the ultrastructure of the endolymphatic sac and in particular the chief cells...... is described, demonstrating that this organ fulfils the morphological criteria of a potential endocrine gland. Accordingly, the chief cells are shown to exhibit all the organelles and characteristics of cells that simultaneously synthesize, secrete, absorb and digest proteins....

Embryo sac development in some representatives of the tribe Cynodonteae (Poaceae

Directory of Open Access Journals (Sweden)

A. Strydom

1994-10-01

Full Text Available Chloris virgata Sw., Cynodon dactylon (L. Pers., Harpochloa falx (L. f. Kuntze, and Tragus berteronianus Schult. have a Polygonum type of embryo sac development. Unreduced embryo sacs were found in Eustachys paspaloides (Vahl Lanza & Mattei,  Harpochloa falx, and  Rendlia altera (Rendle Chiov. Both facultative and obligate apomixis were observed. The Hieracium type of embryo sac development was observed in the aposporic specimens.

Embryo sac development in some representatives of the tribe Cynodonteae (Poaceae)

OpenAIRE

A. Strydom; J. J. Spies

1994-01-01

Chloris virgata Sw., Cynodon dactylon (L.) Pers., Harpochloa falx (L. f.) Kuntze, and Tragus berteronianus Schult. have a Polygonum type of embryo sac development. Unreduced embryo sacs were found in Eustachys paspaloides (Vahl) Lanza & Mattei,  Harpochloa falx, and  Rendlia altera (Rendle) Chiov. Both facultative and obligate apomixis were observed. The Hieracium type of embryo sac development was observed in the aposporic specimens.

Single Assignment C (SAC): High Productivity meets High Performance

NARCIS (Netherlands)

Grelck, C.; Zsók, V.; Horváth, Z.; Plasmeijer, R.

2012-01-01

We present the ins and outs of the purely functional, data parallel programming language SaC (Single Assignment C). SaC defines state- and side-effect-free semantics on top of a syntax resembling that of imperative languages like C/C++/C# or Java: functional programming with curly brackets. In

Probing protein phosphatase substrate binding

DEFF Research Database (Denmark)

Højlys-Larsen, Kim B.; Sørensen, Kasper Kildegaard; Jensen, Knud Jørgen

2012-01-01

Proteomics and high throughput analysis for systems biology can benefit significantly from solid-phase chemical tools for affinity pull-down of proteins from complex mixtures. Here we report the application of solid-phase synthesis of phosphopeptides for pull-down and analysis of the affinity...... profile of the integrin-linked kinase associated phosphatase (ILKAP), a member of the protein phosphatase 2C (PP2C) family. Phosphatases can potentially dephosphorylate these phosphopeptide substrates but, interestingly, performing the binding studies at 4 °C allowed efficient binding to phosphopeptides......, without the need for phosphopeptide mimics or phosphatase inhibitors. As no proven ILKAP substrates were available, we selected phosphopeptide substrates among known PP2Cδ substrates including the protein kinases: p38, ATM, Chk1, Chk2 and RSK2 and synthesized directly on PEGA solid supports through a BAL...

Response to platelet-activating factor in human platelets stored and aged in plasma. Decrease in aggregation, phosphoinositide turnover, and receptor affinity

International Nuclear Information System (INIS)

Shukla, S.D.; Morrison, W.J.; Klachko, D.M.

1989-01-01

Human platelet concentrates were stored in polyolefin bags at 22 to 24 degrees C on a horizontal shaker for up to 8 days. At different intervals, aliquots of platelet-rich plasma (PRP) were removed aseptically and five variables, i.e., platelet counts, morphology, platelet-activating factor (PAF)-stimulated aggregation, phosphoinositide turnover, and [3H]PAF binding to platelet receptors, were studied. The number of platelets did not change during the 8 days of storage. Scanning electron microscopy of the platelets revealed a gradual morphologic change from biconcave flat discs to irregular, crenated forms. The PAF-induced aggregation of platelets declined with time of storage. A decrease to 50 percent of the Day 1 aggregatory response to PAF was evident on Day 2, and there was a further decline to about 20 percent by Day 6. Similarly, PAF receptor-coupled phosphoinositide turnover, as monitored by 32P incorporation into individual phosphoinositides, decreased dramatically with storage. After 2 to 3 days of storage, the phosphoinositide turnover was reduced to 50 percent of the original response, and it continued to decline to about 25 percent of original response by Day 5 or 6. The binding of [3H]PAF to washed human platelets indicated subtle changes between Days 2 and 4, which became more noticeable by Day 6. These results have raised the possibility of changes in the number of the receptors and/or their affinity for the ligand during storage. We conclude that although the number of platelets was maintained during storage for 8 days, a general deterioration of their responses to PAF occurred at the levels of cell surface receptor, transmembrane signaling (phosphoinositide turnover), and response (aggregation)

Tea Contains Potent Inhibitors of Tyrosine Phosphatase PTP1B

OpenAIRE

Ma, Junfeng; Li, Zhe; Xing, Shu; Ho, Wanting Tina; Fu, Xueqi; Zhao, Zhizhuang Joe

2011-01-01

Tea is widely consumed all over the world. Studies have demonstrated the role of tea in prevention and treatment of various chronic diseases including diabetes and obesity, but the underlying mechanism is unclear. PTP1B is a widely expressed tyrosine phosphatase which has been defined as a target for therapeutic drug development to treat diabetes and obesity. In screening for inhibitors of PTP1B, we found that aqueous extracts of teas exhibited potent PTP1B inhibitory effects with an IC50 val...

Insertion of a self-expandable metallic stent in canine lacrimal Sac : a long-term evaluation

Energy Technology Data Exchange (ETDEWEB)

Song, Ho Young; Sung, Kyu Bo; Yoon, Hyun Ki [Univ. of Ulsan, Ulsan (Korea, Republic of). College of Medicine; Kwon, Soon Tae [Chungnam National Univ., Taejon (Korea, Republic of). Medical School; Lee, Ho Jung; Lee, In Chul; Kim, Tae Hyung; Park, Sang Soo; Huh, Soo Jin [Univ. of Ulsan, Ulsan (Korea, Republic of). College of Medicine

1998-01-01

To evaluate the feasibility and long-term outcome of the use of self-expandable metallic Z-stents in the canine lacrimal sac. Stent placement was technically successful and well tolerated in all but one lacrimal sac, in which the stent was misplaced. At three and six months after stent placement, stent wires were not encased by epithelium, but at nine months, and one, two and three years after placement, six of the 12 stents had become encased in a proliferation of this where the stent wires contacted the lacrimal sac wall. In no lacrimal system in which stent placement had been successful was migration, stenosis or obstruction of the lacrimal system observed. One misplaced stent caused obstruction of the lacrimal sac, however . In 11 of 12 case (92%), fluoroscopic placement of an expandable metallic stent in the canine lacrimal sac was successful: in 6 of 8 cases (75%), the stent wires became encased by a proliferation of mucosa, but during long-term follow-up of 9 months to 3 years, no obstruction was observed. (author). 20 refs., 1 tab., 5 figs.

Insertion of a self-expandable metallic stent in canine lacrimal Sac : a long-term evaluation

International Nuclear Information System (INIS)

Song, Ho Young; Sung, Kyu Bo; Yoon, Hyun Ki; Kwon, Soon Tae; Lee, Ho Jung; Lee, In Chul; Kim, Tae Hyung; Park, Sang Soo; Huh, Soo Jin

1998-01-01

To evaluate the feasibility and long-term outcome of the use of self-expandable metallic Z-stents in the canine lacrimal sac. Stent placement was technically successful and well tolerated in all but one lacrimal sac, in which the stent was misplaced. At three and six months after stent placement, stent wires were not encased by epithelium, but at nine months, and one, two and three years after placement, six of the 12 stents had become encased in a proliferation of this where the stent wires contacted the lacrimal sac wall. In no lacrimal system in which stent placement had been successful was migration, stenosis or obstruction of the lacrimal system observed. One misplaced stent caused obstruction of the lacrimal sac, however . In 11 of 12 case (92%), fluoroscopic placement of an expandable metallic stent in the canine lacrimal sac was successful: in 6 of 8 cases (75%), the stent wires became encased by a proliferation of mucosa, but during long-term follow-up of 9 months to 3 years, no obstruction was observed. (author). 20 refs., 1 tab., 5 figs

Sudden unilateral deafness with endolymphatic sac adenocarcinoma: MRI

International Nuclear Information System (INIS)

Gaeta, M.; Blandino, A.; Minutoli, F.; Pandolfo, I.

1999-01-01

A 30-year-old man presented with sudden left deafness and vertigo. CT showed an osteolytic retrolabyrinthine tumour of the left temporal bone. High signal from the tumour and labyrinth was seen on fat-suppressed T 1-weighted images. At surgery, a haemorrhagic papillary-cystic adenocarcinoma of the endolymphatic sac was found. (orig.)

Sudden unilateral deafness with endolymphatic sac adenocarcinoma: MRI

Energy Technology Data Exchange (ETDEWEB)

Gaeta, M.; Blandino, A.; Minutoli, F.; Pandolfo, I. [Inst. of Radiological Sciences, Univ. of Messina (Italy)

1999-10-01

A 30-year-old man presented with sudden left deafness and vertigo. CT showed an osteolytic retrolabyrinthine tumour of the left temporal bone. High signal from the tumour and labyrinth was seen on fat-suppressed T 1-weighted images. At surgery, a haemorrhagic papillary-cystic adenocarcinoma of the endolymphatic sac was found. (orig.)

Unique players in the BMP pathway: Small C-terminal domain phosphatases dephosphorylate Smad1 to attenuate BMP signaling

Science.gov (United States)

Knockaert, Marie; Sapkota, Gopal; Alarcón, Claudio; Massagué, Joan; Brivanlou, Ali H.

2006-01-01

Smad transcription factors are key signal transducers for the TGF-β/bone morphogenetic protein (BMP) family of cytokines and morphogens. C-terminal serine phosphorylation by TGF-β and BMP membrane receptors drives Smads into the nucleus as transcriptional regulators. Dephosphorylation and recycling of activated Smads is an integral part of this process, which is critical for agonist sensing by the cell. However, the nuclear phosphatases involved have remained unknown. Here we provide functional, biochemical, and embryological evidence identifying the SCP (small C-terminal domain phosphatase) family of nuclear phosphatases as mediators of Smad1 dephosphorylation in the BMP signaling pathway in vertebrates. Xenopus SCP2/Os4 inhibits BMP activity in the presumptive ectoderm and leads to neuralization. In Xenopus embryos, SCP2/Os4 and human SCP1, 2, and 3 cause selective dephosphorylation of Smad1 compared with Smad2, inhibiting BMP- and Smad1-dependent transcription and leading to the induction of the secondary dorsal axis. In human cells, RNAi-mediated depletion of SCP1 and SCP2 increases the extent and duration of Smad1 phosphorylation in response to BMP, the transcriptional action of Smad1, and the strength of endogenous BMP gene responses. The present identification of the SCP family as Smad C-terminal phosphatases sheds light on the events that attenuate Smad signaling and reveals unexpected links to the essential phosphatases that control RNA polymerase II in eukaryotes. PMID:16882717

The echoic pseudogestational sac of ectopic pregnancy simulating early intrauterine pregnancy.

Science.gov (United States)

Schaffer, R M; Stein, K; Shih, Y H; Goodman, J D

1983-05-01

The sonographic features of ectopic pregnancy have been well documented. When an early intrauterine pregnancy is identified or an obvious extrauterine sac is visualized, diagnosis is not a problem; but often a sac is seen within the uterus that may contain a well-defined rind and even internal echoes simulating an early fetal pole. This has been mistaken for an early intrauterine pregnancy. In this review, four patients with pseudogestational sacs had internal echoes within the sac, and two of them ultimately underwent dilatation and curettage, which revealed blood clots. This supports the assertion that fetal cardiac activity and/or fetal motion should be demonstrated within a fetal pole before the diagnosis of ectopic pregnancy is excluded.

Direct determination of phosphatase activity from physiological substrates in cells.

Directory of Open Access Journals (Sweden)

Zhongyuan Ren

Full Text Available A direct and continuous approach to determine simultaneously protein and phosphate concentrations in cells and kinetics of phosphate release from physiological substrates by cells without any labeling has been developed. Among the enzymes having a phosphatase activity, tissue non-specific alkaline phosphatase (TNAP performs indispensable, multiple functions in humans. It is expressed in numerous tissues with high levels detected in bones, liver and neurons. It is absolutely required for bone mineralization and also necessary for neurotransmitter synthesis. We provided the proof of concept that infrared spectroscopy is a reliable assay to determine a phosphatase activity in the osteoblasts. For the first time, an overall specific phosphatase activity in cells was determined in a single step by measuring simultaneously protein and substrate concentrations. We found specific activities in osteoblast like cells amounting to 116 ± 13 nmol min(-1 mg(-1 for PPi, to 56 ± 11 nmol min(-1 mg(-1 for AMP, to 79 ± 23 nmol min(-1 mg(-1 for beta-glycerophosphate and to 73 ± 15 nmol min(-1 mg(-1 for 1-alpha-D glucose phosphate. The assay was also effective to monitor phosphatase activity in primary osteoblasts and in matrix vesicles. The use of levamisole--a TNAP inhibitor--served to demonstrate that a part of the phosphatase activity originated from this enzyme. An IC50 value of 1.16 ± 0.03 mM was obtained for the inhibition of phosphatase activity of levamisole in osteoblast like cells. The infrared assay could be extended to determine any type of phosphatase activity in other cells. It may serve as a metabolomic tool to monitor an overall phosphatase activity including acid phosphatases or other related enzymes.

pH sensing via bicarbonate-regulated ‘soluble’ adenylyl cyclase (sAC

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Nawreen eRahman

2013-11-01

Full Text Available Soluble adenylyl cyclase (sAC is a source of the second messenger cyclic adenosine 3',5' monophosphate (cAMP. sAC is directly regulated by bicarbonate (HCO3- ions. In living cells, HCO3- ions are in nearly instantaneous equilibrium with carbon dioxide (CO2 and pH due to the ubiquitous presence of carbonic anhydrases. Numerous biological processes are regulated by CO2, HCO3-, and/or pH, and in a number of these, sAC has been shown to function as a physiological CO2/HCO3/pH sensor. In this review, we detail the known pH sensing functions of sAC, and we discuss two highly-studied, pH-dependent pathways in which sAC might play a role.

Increased PTP1B expression and phosphatase activity in colorectal cancer results in a more invasive phenotype and worse patient outcome.

Science.gov (United States)

Hoekstra, Elmer; Das, Asha M; Swets, Marloes; Cao, Wanlu; van der Woude, C Janneke; Bruno, Marco J; Peppelenbosch, Maikel P; Kuppen, Peter J K; Ten Hagen, Timo L M; Fuhler, Gwenny M

2016-04-19

Cell signaling is dependent on the balance between phosphorylation of proteins by kinases and dephosphorylation by phosphatases. This balance if often disrupted in colorectal cancer (CRC), leading to increased cell proliferation and invasion. For many years research has focused on the role of kinases as potential oncogenes in cancer, while phosphatases were commonly assumed to be tumor suppressive. However, this dogma is currently changing as phosphatases have also been shown to induce cancer growth. One of these phosphatases is protein tyrosine phosphatase 1B (PTP1B). Here we report that the expression of PTP1B is increased in colorectal cancer as compared to normal tissue, and that the intrinsic enzymatic activity of the protein is also enhanced. This suggests a role for PTP1B phosphatase activity in CRC formation and progression. Furthermore, we found that increased PTP1B expression is correlated to a worse patient survival and is an independent prognostic marker for overall survival and disease free survival. Knocking down PTP1B in CRC cell lines results in a less invasive phenotype with lower adhesion, migration and proliferation capabilities. Together, these results suggest that inhibition of PTP1B activity is a promising new target in the treatment of colorectal cancer and the prevention of metastasis.

3' Phosphatase activity toward phosphatidylinositol 3,4-bisphosphate [PI(3,4)P2] by voltage-sensing phosphatase (VSP).

Science.gov (United States)

Kurokawa, Tatsuki; Takasuga, Shunsuke; Sakata, Souhei; Yamaguchi, Shinji; Horie, Shigeo; Homma, Koichi J; Sasaki, Takehiko; Okamura, Yasushi

2012-06-19

Voltage-sensing phosphatases (VSPs) consist of a voltage-sensor domain and a cytoplasmic region with remarkable sequence similarity to phosphatase and tensin homolog deleted on chromosome 10 (PTEN), a tumor suppressor phosphatase. VSPs dephosphorylate the 5' position of the inositol ring of both phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P(3)] and phosphatidylinositol 4,5-bisphosphate [PI(4,5)P(2)] upon voltage depolarization. However, it is unclear whether VSPs also have 3' phosphatase activity. To gain insights into this question, we performed in vitro assays of phosphatase activities of Ciona intestinalis VSP (Ci-VSP) and transmembrane phosphatase with tensin homology (TPTE) and PTEN homologous inositol lipid phosphatase (TPIP; one human ortholog of VSP) with radiolabeled PI(3,4,5)P(3). TLC assay showed that the 3' phosphate of PI(3,4,5)P(3) was not dephosphorylated, whereas that of phosphatidylinositol 3,4-bisphosphate [PI(3,4)P(2)] was removed by VSPs. Monitoring of PI(3,4)P(2) levels with the pleckstrin homology (PH) domain from tandem PH domain-containing protein (TAPP1) fused with GFP (PH(TAPP1)-GFP) by confocal microscopy in amphibian oocytes showed an increase of fluorescence intensity during depolarization to 0 mV, consistent with 5' phosphatase activity of VSP toward PI(3,4,5)P(3). However, depolarization to 60 mV showed a transient increase of GFP fluorescence followed by a decrease, indicating that, after PI(3,4,5)P(3) is dephosphorylated at the 5' position, PI(3,4)P(2) is then dephosphorylated at the 3' position. These results suggest that substrate specificity of the VSP changes with membrane potential.

Loss of SYNJ1 dual phosphatase activity leads to early onset refractory seizures and progressive neurological decline

DEFF Research Database (Denmark)

Hardies, Katia; Cai, Yiying; Jardel, Claude

2016-01-01

SYNJ1 encodes a polyphosphoinositide phosphatase, synaptojanin 1, which contains two consecutive phosphatase domains and plays a prominent role in synaptic vesicle dynamics. Autosomal recessive inherited variants in SYNJ1 have previously been associated with two different neurological diseases...... with intractable epilepsy and tau pathology. We performed whole exome or genome sequencing in three independent sib pairs with early onset refractory seizures and progressive neurological decline, and identified novel segregating recessive SYNJ1 defects. A homozygous missense variant resulting in an amino acid...

Bradykinin B2 receptor-mediated phosphoinositide hydrolysis in bovine cultured tracheal smooth muscle cells.

OpenAIRE

Marsh, K. A.; Hill, S. J.

1992-01-01

1. Bovine tracheal smooth muscle cells were established in culture to study agonist-induced phosphoinositide (PI) hydrolysis in this tissue. 2. Bradykinin (0.1 nM-10 microM) evoked a concentration-dependent increase (log EC50 (M) = -9.4 +/- 0.2; n = 8) in the accumulation of total [3H]-inositol phosphates in cultured tracheal smooth muscle cells whereas the selective B1 receptor agonist des-Arg9-bradykinin (10 microM) was significantly less effective (16% of bradykinin maximal response; relat...

The Evolutionary Economics of Embryonic-Sac Fluids in Squamate Reptiles.

Science.gov (United States)

Bonnet, Xavier; Naulleau, Guy; Shine, Richard

2017-03-01

The parchment-shelled eggs of squamate reptiles take up substantial water from the nest environment, enabling the conversion of yolk into neonatal tissue and buffering the embryo against the possibility of subsequent dry weather. During development, increasing amounts of water are stored in the embryonic sacs (i.e., membranes around the embryo: amnion, allantois, and chorion). The evolution of viviparity (prolonged uterine retention of developing embryos) means that embryonic-sac fluid storage now imposes a cost (increased maternal burdening), confers less benefit (because the mother buffers fetal water balance), and introduces a potential conflict among uterine siblings (for access to finite water supplies). Our data on nine species of squamate reptiles and published information on three species show that the embryonic-sac fluids comprise around 33% of neonatal mass in viviparous species versus 94% in full-term eggs of oviparous squamates. Data on parturition in 149 vipers (Vipera aspis, a viviparous species) show that larger offspring store more fluids in their fetal sacs and that an increase in litter size is associated with a decrease in fluid-sac mass per offspring. Overall, the evolutionary transition from oviparity to viviparity may have substantially altered selective forces on offspring packaging and created competition among offspring for access to water reserves during embryonic development.

Age and egg-sac loss determine maternal behaviour and locomotor activity of wolf spiders (Araneae, Lycosidae).

Science.gov (United States)

Ruhland, Fanny; Chiara, Violette; Trabalon, Marie

2016-11-01

Wolf spiders' (Lycosidae) maternal behaviour includes a specific phase called "egg brooding" which consists of guarding and carrying an egg-sac throughout the incubation period. The transport of an egg-sac can restrict mothers' exploratory and locomotor activity, in particular when foraging. The present study details the ontogeny of maternal behaviour and assesses the influence of age of egg-sac (or embryos' developmental stage) on vagrant wolf spider Pardosa saltans females' exploration and locomotion. We observed these spiders' maternal behaviour in the laboratory and evaluated their locomotor activity using a digital activity recording device. Our subjects were virgin females (without egg-sac) and first time mothers (with her egg-sac) who were divided into three groups. The first group of mothers were tested on the day the egg-sac was built (day 0), and the females of the other two groups were tested 10 or 15days after they had built their egg-sac. We evaluated the effects of the presence and the loss of egg-sac on mothers' activity. Pardosa saltans females' behaviour depended on mothers' physiological state and/or age of egg-sac (developmental stage of embryos). Virgin females' behaviour was not modified by the presence of an egg-sac in their environment. Mothers' reactions to the presence, the loss and the recovery of their egg-sac varied during the maternal cycle. Maternal behaviour changed with age of egg-sac, but the levels of locomotor activity of mothers with egg-sacs was similar to those of virgin females. Loss of egg-sac modified the maternal behaviour and locomotor activity of all mothers; these modifications were greater on "day 15" when embryos had emerged from eggs. All mothers were able to retrieve their egg-sacs and to re-attach them to their spinnerets. Copyright © 2016 Elsevier B.V. All rights reserved.

Target of rapamycin complex 1 and Tap42-associated phosphatases are required for sensing changes in nitrogen conditions in the yeast Saccharomyces cerevisiae.

Science.gov (United States)

Li, Jinmei; Yan, Gonghong; Liu, Sichi; Jiang, Tong; Zhong, Mingming; Yuan, Wenjie; Chen, Shaoxian; Zheng, Yin; Jiang, Yong; Jiang, Yu

2017-12-01

In yeast target of rapamycin complex 1 (TORC1) and Tap42-associated phosphatases regulate expression of genes involved in nitrogen limitation response and the nitrogen discrimination pathway. However, it remains unclear whether TORC1 and the phosphatases are required for sensing nitrogen conditions. Utilizing temperature sensitive mutants of tor2 and tap42, we examined the role of TORC1 and Tap42 in nuclear entry of Gln3, a key transcription factor in yeast nitrogen metabolism, in response to changes in nitrogen conditions. Our data show that TORC1 is essential for Gln3 nuclear entry upon nitrogen limitation and downshift in nitrogen quality. However, Tap42-associated phosphatases are required only under nitrogen limitation condition. In cells grown in poor nitrogen medium, the nitrogen permease reactivator kinase (Npr1) inhibits TORC1 activity and alters its association with Tap42, rendering Tap42-associated phosphatases unresponsive to nitrogen limitation. These findings demonstrate a direct role for TORC1 and Tap42-associated phosphatases in sensing nitrogen conditions and unveil an Npr1-dependent mechanism that controls TORC1 and the phosphatases in response to changes in nitrogen quality. © 2017 John Wiley & Sons Ltd.

Sac Angiography and Glue Embolization in Emergency Endovascular Aneurysm Repair for Ruptured Abdominal Aortic Aneurysm

Energy Technology Data Exchange (ETDEWEB)

Koike, Yuya, E-mail: r06118@hotmail.co.jp; Nishimura, Jun-ichi, E-mail: jun-ichi-n@nifty.com; Hase, Soichiro, E-mail: haseman@hotmail.co.jp; Yamasaki, Motoshige, E-mail: genyamasaki@gmail.com [Kawasaki Saiwai Hospital, Department of Interventional Radiology (Japan)

2015-04-15

PurposeThe purpose of this study was to demonstrate a sac angiography technique and evaluate the feasibility of N-butyl cyanoacrylate (NBCA) embolization of the ruptured abdominal aortic aneurysm (AAA) sac in emergency endovascular aneurysm repair (EVAR) in hemodynamically unstable patients.MethodsA retrospective case series of three patients in whom sac angiography was performed during emergency EVAR for ruptured AAA was reviewed. After stent graft deployment, angiography within the sac of aneurysm (sac angiography) was performed by manually injecting 10 ml of contrast material through a catheter to identify the presence and site of active bleeding. In two patients, sac angiography revealed active extravasation of the contrast material, and NBCA embolization with a coaxial catheter system was performed to achieve prompt sealing.ResultsSac angiography was successful in all three patients. In the two patients who underwent NBCA embolization for aneurysm sac bleeding, follow-up computed tomography (CT) images demonstrated the accumulation of NBCA consistent with the bleeding site in preprocedural CT images.ConclusionsEVAR is associated with a potential risk of ongoing bleeding from type II or IV endoleaks into the disrupted aneurysm sac in patients with severe coagulopathy. Therefore, sac angiography and NBCA embolization during emergency EVAR may represent a possible technical improvement in the treatment of ruptured AAA in hemodynamically unstable patients.

S -Nitrosylation inhibits the kinase activity of tomato phosphoinositide-dependent kinase 1 (PDK1)

Energy Technology Data Exchange (ETDEWEB)

Liu, Jian-Zhong; Duan, Jicheng; Ni, Min; Liu, Zhen; Qiu, Wen-Li; Whitham, Steven A.; Qian, Wei-Jun

2017-09-29

It is well known that the reactive oxygen species, nitric oxide (NO), can trigger cell death in plants, but the underlying molecular mechanisms are not well understood. Here, we provide evidence that NO may trigger cell death in tomato (Solanum lycopersicon) through inhibiting the phosphoinositide-dependent kinase 1 (PDK1) kinase activity via S-nitrosylation. Biotin-switch assays and LC-MS/MS analyses demonstrated that SlPDK1 was a target of S-nitrosylation modification, which primarily occurred on the cysteine residue at position 128 (Cys128). Accordingly, the kinase activity of SlPDK1 was inhibited by S-nitrosoglutathione (GSNO) both in vitro and in vivo in a concentration-dependent manner, indicating that SlPDK1 activity is regulated by S-nitrosylation. The inhibition of SlPDK1 kinase activity by GSNO was reversible in the presence of a reducing agent but synergistically enhanced by hydrogen peroxide (H2O2). Mutation of Cys128 to serine completely abolished SlPDK1 kinase activity, suggesting that S-nitrosylation of Cys128 is responsible for the inhibition of the kinase activity of SlPDK1. In sum, our results established a potential link between NO-triggered cell death and inhibition of the kinase activity of tomato PDK1, a conserved negative regulator of cell death in yeasts, mammals and plants. Nitric oxide (NO) potentiates the induction of hypersensitive cell death in soybean cells by reactive oxygen species (ROS) (1). However, the molecular mechanism of the NO-induced cell death remains an enigma. One potential mechanism is that the activity of proteins that control cell death may be altered by a post-translational modification, S-nitrosylation. S-nitrosylation is the addition of the NO moiety to thiol groups, including cysteine (Cys) residues in proteins, to form S-nitrosothiols (SNOs). S-nitrosylation is an enzyme-independent post-translational and labile modification that can function as an on/off switch of protein activity (2- 4). Thousands of diverse

Spinal movement and dural sac compression during airway management in a cadaveric model with atlanto-occipital instability.

Science.gov (United States)

Liao, Shiyao; Schneider, Niko R E; Weilbacher, Frank; Stehr, Anne; Matschke, Stefan; Grützner, Paul A; Popp, Erik; Kreinest, Michael

2017-12-01

To analyze the compression of the dural sac and the cervical spinal movement during performing different airway interventions in case of atlanto-occipital dislocation. In six fresh cadavers, atlanto-occipital dislocation was performed by distracting the opened atlanto-occipital joint capsule and sectioning the tectorial membrane. Airway management was done using three airway devices (direct laryngoscopy, video laryngoscopy, and insertion of a laryngeal tube). The change of dural sac's width and intervertebral angulation in stable and unstable atlanto-occipital conditions were recorded by video fluoroscopy with myelography. Three-dimensional overall movement of cervical spine was measured in a wireless human motion track system. Compared with a mean dural sac compression of - 0.5 mm (- 0.7 to - 0.3 mm) in stable condition, direct laryngoscopy caused an increased dural sac compression of - 1.6 mm (- 1.9 to - 0.6 mm, p = 0.028) in the unstable atlanto-occipital condition. No increased compression on dural sac was found using video laryngoscopy or the laryngeal tube. Moreover, direct laryngoscopy caused greater overall extension and rotation of cervical spine than laryngeal tube insertion in both stable and unstable conditions. Among three procedures, the insertion of a laryngeal tube took the shortest time. In case of atlanto-occipital dislocation, intubation using direct laryngoscopy exacerbates dural sac compression and may cause damage to the spinal cord.

A phosphoinositide 3-kinase (PI3K)-serum- and glucocorticoid-inducible kinase 1 (SGK1) pathway promotes Kv7.1 channel surface expression by inhibiting Nedd4-2 protein

DEFF Research Database (Denmark)

Andersen, Martin Nybo; Krzystanek, Katarzyna; Petersen, Frederic

2013-01-01

Epithelial cell polarization involves several kinase signaling cascades that eventually divide the surface membrane into an apical and a basolateral part. One kinase, which is activated during the polarization process, is phosphoinositide 3-kinase (PI3K). In MDCK cells, the basolateral potassium...... channel Kv7.1 requires PI3K activity for surface-expression during the polarization process. Here, we demonstrate that Kv7.1 surface expression requires tonic PI3K activity as PI3K inhibition triggers endocytosis of these channels in polarized MDCK. Pharmacological inhibition of SGK1 gave similar results...... as PI3K inhibition, whereas overexpression of constitutively active SGK1 overruled it, suggesting that SGK1 is the primary downstream target of PI3K in this process. Furthermore, knockdown of the ubiquitin ligase Nedd4-2 overruled PI3K inhibition, whereas a Nedd4-2 interaction-deficient Kv7.1 mutant...

Genetic interaction network of the Saccharomyces cerevisiae type 1 phosphatase Glc7

Directory of Open Access Journals (Sweden)

Neszt Michael

2008-07-01

Full Text Available Abstract Background Protein kinases and phosphatases regulate protein phosphorylation, a critical means of modulating protein function, stability and localization. The identification of functional networks for protein phosphatases has been slow due to their redundant nature and the lack of large-scale analyses. We hypothesized that a genome-scale analysis of genetic interactions using the Synthetic Genetic Array could reveal protein phosphatase functional networks. We apply this approach to the conserved type 1 protein phosphatase Glc7, which regulates numerous cellular processes in budding yeast. Results We created a novel glc7 catalytic mutant (glc7-E101Q. Phenotypic analysis indicates that this novel allele exhibits slow growth and defects in glucose metabolism but normal cell cycle progression and chromosome segregation. This suggests that glc7-E101Q is a hypomorphic glc7 mutant. Synthetic Genetic Array analysis of glc7-E101Q revealed a broad network of 245 synthetic sick/lethal interactions reflecting that many processes are required when Glc7 function is compromised such as histone modification, chromosome segregation and cytokinesis, nutrient sensing and DNA damage. In addition, mitochondrial activity and inheritance and lipid metabolism were identified as new processes involved in buffering Glc7 function. An interaction network among 95 genes genetically interacting with GLC7 was constructed by integration of genetic and physical interaction data. The obtained network has a modular architecture, and the interconnection among the modules reflects the cooperation of the processes buffering Glc7 function. Conclusion We found 245 genes required for the normal growth of the glc7-E101Q mutant. Functional grouping of these genes and analysis of their physical and genetic interaction patterns bring new information on Glc7-regulated processes.

Experimental demonstration of variable weight SAC-OCDMA system for QoS differentiation

Science.gov (United States)

Seyedzadeh, Saleh; Mahdiraji, Ghafour Amouzad; Sahbudin, Ratna Kalos Zakiah; Abas, Ahmad Fauzi; Anas, Siti Barirah Ahmad

2014-10-01

In this paper the experimental and simulation results of variable-weight spectral amplitude coding optical code division multiple access (VW-SAC-OCDMA) system is demonstrated. In the proposed system, three users with weights of 6, 4 and 2 each operating at data rate of 1.25 Gb/s represent video, data and voice services, respectively. Results show that for back-to-back system minimum average power of -20 dBm per chip is required to maintain the acceptable performance. Transmission up to 60 km of fiber is demonstrated. Using mathematical approximation the capacity of VW-SAC-OCDMA system is demonstrated.

Yolk sac development in lizards (Lacertilia: Scincidae): New perspectives on the egg of amniotes.

Science.gov (United States)

Stewart, James R; Thompson, Michael B

2017-04-01

Embryos of oviparous reptiles develop on the surface of a large mass of yolk, which they metabolize to become relatively large hatchlings. Access to the yolk is provided by tissues growing outward from the embryo to cover the surface of the yolk. A key feature of yolk sac development is a dedicated blood vascular system to communicate with the embryo. The best known model for yolk sac development and function of oviparous amniotes is based on numerous studies of birds, primarily domestic chickens. In this model, the vascular yolk sac forms the perimeter of the large yolk mass and is lined by a specialized epithelium, which takes up, processes and transports yolk nutrients to the yolk sac blood vessels. Studies of lizard yolk sac development, dating to more than 100 years ago, report characteristics inconsistent with this model. We compared development of the yolk sac from oviposition to near hatching in embryonic series of three species of oviparous scincid lizards to consider congruence with the pattern described for birds. Our findings reinforce results of prior studies indicating that squamate reptiles mobilize and metabolize the large yolk reserves in their eggs through a process unknown in other amniotes. Development of the yolk sac of lizards differs from birds in four primary characteristics, migration of mesoderm, proliferation of endoderm, vascular development and cellular diversity within the yolk sac cavity. Notably, all of the yolk is incorporated into cells relatively early in development and endodermal cells within the yolk sac cavity align along blood vessels which course throughout the yolk sac cavity. The pattern of uptake of yolk by endodermal cells indicates that the mechanism of yolk metabolism differs between lizards and birds and that the evolution of a fundamental characteristic of embryonic nutrition diverged in these two lineages. Attributes of the yolk sac of squamates reveal the existence of phylogenetic diversity among amniote lineages

Protection against gamma-radiation injury by protein tyrosine phosphatase 1B

Directory of Open Access Journals (Sweden)

Marina Mojena

2018-07-01

Full Text Available Protein tyrosine phosphatase 1B (PTP1B is widely expressed in mammalian tissues, in particular in immune cells, and plays a pleiotropic role in dephosphorylating many substrates. Moreover, PTP1B expression is enhanced in response to pro-inflammatory stimuli and to different cell stressors. Taking advantage of the use of mice deficient in PTP1B we have investigated the effect of γ-radiation in these animals and found enhanced lethality and decreased respiratory exchange ratio vs. the corresponding wild type animals. Using bone-marrow derived macrophages and mouse embryonic fibroblasts (MEFs from wild-type and PTP1B-deficient mice, we observed a differential response to various cell stressors. PTP1B-deficient macrophages exhibited an enhanced response to γ-radiation, UV-light, LPS and S-nitroso-glutathione. Macrophages exposed to γ-radiation show DNA damage and fragmentation, increased ROS production, a lack in GSH elevation and enhanced acidic β-galactosidase activity. Interestingly, these differences were not observed in MEFs. Differential gene expression analysis of WT and KO macrophages revealed that the main pathways affected after irradiation were an up-regulation of protein secretion, TGF-β signaling and angiogenesis among other, and downregulation of Myc targets and Hedgehog signaling. These results demonstrate a key role for PTP1B in the protection against the cytotoxicity of irradiation in intact animal and in macrophages, which might be therapeutically relevant. Keywords: Protein tyrosine phosphatase, Cell viability, Irradiation sensitivity, Lethality, p53

Phosphoinositide protein kinase PDPK1 is a crucial cell signaling mediator in multiple myeloma.

Science.gov (United States)

Chinen, Yoshiaki; Kuroda, Junya; Shimura, Yuji; Nagoshi, Hisao; Kiyota, Miki; Yamamoto-Sugitani, Mio; Mizutani, Shinsuke; Sakamoto, Natsumi; Ri, Masaki; Kawata, Eri; Kobayashi, Tsutomu; Matsumoto, Yosuke; Horiike, Shigeo; Iida, Shinsuke; Taniwaki, Masafumi

2014-12-15

Multiple myeloma is a cytogenetically/molecularly heterogeneous hematologic malignancy that remains mostly incurable, and the identification of a universal and relevant therapeutic target molecule is essential for the further development of therapeutic strategy. Herein, we identified that 3-phosphoinositide-dependent protein kinase 1 (PDPK1), a serine threonine kinase, is expressed and active in all eleven multiple myeloma-derived cell lines examined regardless of the type of cytogenetic abnormality, the mutation state of RAS and FGFR3 genes, or the activation state of ERK and AKT. Our results revealed that PDPK1 is a pivotal regulator of molecules that are essential for myelomagenesis, such as RSK2, AKT, c-MYC, IRF4, or cyclin Ds, and that PDPK1 inhibition caused the growth inhibition and the induction of apoptosis with the activation of BIM and BAD, and augmented the in vitro cytotoxic effects of antimyeloma agents in myeloma cells. In the clinical setting, PDPK1 was active in myeloma cells of approximately 90% of symptomatic patients at diagnosis, and the smaller population of patients with multiple myeloma exhibiting myeloma cells without active PDPK1 showed a significantly less frequent proportion of the disease stage III by the International Staging System and a significantly more favorable prognosis, including the longer overall survival period and the longer progression-free survival period by bortezomib treatment, than patients with active PDPK1, suggesting that PDPK1 activation accelerates the disease progression and the resistance to treatment in multiple myeloma. Our study demonstrates that PDPK1 is a potent and a universally targetable signaling mediator in multiple myeloma regardless of the types of cytogenetic/molecular profiles. ©2014 American Association for Cancer Research.

Basement membrane components secreted by mouse yolk sac carcinoma cell lines

DEFF Research Database (Denmark)

Damjanov, A; Wewer, U M; Tuma, B

1990-01-01

Three new cell lines (NE, ME, LRD) were cloned from mouse-embryo-derived teratocarcinomas and characterized on the basis of developmental, ultrastructural, and cytochemical criteria as nullipotent embryonal carcinoma (EC), pure parietal yolk sac (PYS) carcinoma and mixed parieto-visceral yolk sac...

Participation of the phosphoinositide metabolism in the hypersensitive response of Citrus limon against Alternaria alternata

Directory of Open Access Journals (Sweden)

XIMENA ORTEGA

2001-01-01

Full Text Available Lemon seedlings inoculated with Alternaria alternata develop a hypersensitive response (HR that includes the induction of Phenylalanine ammonia-lyase (PAL, E. C. 4.3.1.5 and the synthesis of scoparone. The signal transduction pathway involved in the development of this response is unknown. We used several inhibitors of the Phosphoinositide (PI animal system to study a possible role of Inositol-1,4,5-triphosphate (IP3 in the transduction of the fungal conidia signal in Citrus limon. The HR was only partially inhibited by EGTA, suggesting that not only external but internal calcium as well are necessary for a complete development of the HR. In this plant system, Alternaria alternata induced an early accumulation of the second messenger IP3. When lemon seedlings were watered long term with LiCl, an inhibitor of the phosphoinositide cycle, the IP3 production was reduced, and the LiCl-watered plants could neither induce PAL nor synthesize scoparone in response to fungal conidia. Furthermore, neomycin, a Phospholipase C (PLC, E. C. 3.1.4.3 inhibitor, also inhibited PAL induction and scoparone synthesis in response to A. alternata. These results suggest that IP3 could be involved in the signal transduction pathway for the development of the HR of Citrus limon against A. alternata

Aortic aneurysm sac pressure measurements after endovascular repair using an implantable remote sensor: initial experience and short-term follow-up

International Nuclear Information System (INIS)

Hoppe, Hanno; Kaufman, John A.; Segall, Jocelyn A.; Liem, Timothy K.; Landry, Gregory J.

2008-01-01

The purpose of this single-center study was to report our initial experience with an implantable remote pressure sensor for aneurysm sac pressure measurement in patients post-endovascular aneurysm repair (EVAR) including short-term follow-up. A pressure sensor (EndoSure, Atlanta, GA) was implanted in 12 patients treated with different commercially available aortic endografts for EVAR. Pressure was read pre- and post-EVAR in the operating room. One-month follow-up (30 days ± 6 days) was performed including sac pressure readings and IV contrast CT scans. Variables were compared using the paired Student's t test. An intraprocedure type-I endoleak and a type-III endoleak were successfully treated resulting in decreasing sac pressures. In all patients, post-EVAR systolic sac pressure decreased by an average of 33% (P ≤ 0.005) compared to pre-EVAR measurements. One-month follow-up demonstrated a 47% decrease in systolic sac pressure (P ≤ 0.05). On follow-up CT scans, the average maximum aneurysm diameter pre-EVAR was 6.3 ± 1.6 cm and post-EVAR 6.0 ± 1.7 cm (P≤0.05). The diameter of the aneurysm sac was larger only in one patient with a type-III endoleak. Remote sac pressure measurement may provide important information in addition to imaging and may help to reduce the number of follow-up CT scans. (orig.)

Pinocytosis in the rat visceral yolk sac

International Nuclear Information System (INIS)

Duncan, R.; Lloyd, J.B.

1978-01-01

Low temperature, 2,4-dinitrophenol and moniodoacetate could each completely abolish the pinocytic uptake of 125 I-labelled polyvinylpyrrolidone, 125 I-labelled bovine serum albumin or colloidal 198 Au by 17.5-day rat visceral yolk sac cultured in vitro. Cytochalasin B and colchicine caused a partial and dose-dependent inhibition. It is concluded that the mechanism of pinocytic uptake of these substrates is not micropinocytosis as conventionally defined. Removal of extracellular calcium or the presence of theophylline inhibited liquid-phase pinocytosis by the rat yolk sac, whereas addition of ouabain caused a biphasic response: a slight stimulation of pinosome formation at a low concentration, and an inhibitory effect at a higher concentration. (Auth.)

Regulated binding of PTP1B-like phosphatase to N-cadherin: control of cadherin-mediated adhesion by dephosphorylation of beta-catenin

Science.gov (United States)

1996-01-01

Cadherins are a family of cell-cell adhesion molecules which play a central role in controlling morphogenetic movements during development. Cadherin function is regulated by its association with the actin containing cytoskeleton, an association mediated by a complex of cytoplasmic proteins, the catenins: alpha, beta, and gamma. Phosphorylated tyrosine residues on beta-catenin are correlated with loss of cadherin function. Consistent with this, we find that only nontyrosine phosphorylated beta-catenin is associated with N-cadherin in E10 chick retina tissue. Moreover, we demonstrate that a PTP1B-like tyrosine phosphatase associates with N-cadherin and may function as a regulatory switch controlling cadherin function by dephosphorylating beta-catenin, thereby maintaining cells in an adhesion-competent state. The PTP1B-like phosphatase is itself tyrosine phosphorylated. Moreover, both direct binding experiments performed with phosphorylated and dephosphorylated molecules, and treatment of cells with tyrosine kinase inhibitors indicate that the interaction of the PTP1B-like phosphatase with N-cadherin depends on its tyrosine phosphorylation. Concomitant with the tyrosine kinase inhibitor-induced loss of the PTP1B-like phosphatase from its association with N-cadherin, phosphorylated tyrosine residues are retained on beta-catenin, the association of N- cadherin with the actin containing cytoskeleton is lost and N-cadherin- mediated cell adhesion is prevented. Tyrosine phosphatase inhibitors also result in the accumulation of phosphorylated tyrosine residues on beta-catenin, loss of the association of N-cadherin with the actin- containing cytoskeleton, and prevent N-cadherin mediated adhesion, presumably by directly blocking the function of the PTP1B-like phosphatase. We previously showed that the binding of two ligands to the cell surface N-acetylgalactosaminylphosphotransferase (GalNAcPTase), the monoclonal antibody 1B11 and a proteoglycan with a 250-kD core protein

Preparative resolution of D,L-threonine catalyzed by immobilized phosphatase.

Science.gov (United States)

Scollar, M P; Sigal, G; Klibanov, A M

1985-03-01

Hydrolysis of L- and D-O-phosphothreonines catalyzed by four different phosphatases, alkaline phosphatases from calf intestine and E. coli and acid phosphatases from wheat germ and potato, has been kinetically studied. Alkaline phosphatases were found to have comparable reactivities towards the optical isomers. On the other hand, both acid phosphatases displayed a marked stereoselectivity, hydrolyzing the L-ester much faster than its D counterpart. Wheat germ acid phosphatase was the most stereoselective enzyme: V(L)/V(D) = 24 and K(m,L)/K(m,D) = 0.17. This enzyme was immobilized (in k-carrageenan gel, followed by crosslinking with glutaraldehyde) and used for the preparative resolution of D,L-threonine: the latter was first chemically O-phosphorylated and then asymmetrically hydrolyzed by the immobilized phosphatase. As a result, gram quantities of L-threonine of high optical purity and O-phospho-D-threonine were prepared. Immobilized wheat germ phosphatase has been tested for the resolution of other racemic alcohols: serine, 2-amino-1-butanol, 1-amino-2-propanol, 2-octanol, and menthol. In all those cases, the enzyme was either not sufficiently stereoselective or too slow for preparative resolutions.

Determination of the inferior border of the thecal sac using magnetic resonance imaging: implications on craniospinal irradiation

International Nuclear Information System (INIS)

Scharf, Carole B.; Goldberg, Kenneth; Paulino, Arnold C.

1996-01-01

Purpose: Craniospinal irradiation (CSI) is employed in medulloblastoma and other intracranial malignancies that can seed the neuro axis. Care must be taken to adequately cover the entire craniospinal axis, including the distal thecal sac. The inferior border of the craniospinal field has traditionally been placed at the bottom of the S2 vertebra. The purpose of this study is to review the level of thecal sac termination in children undergoing CSI using Magnetic Resonance Imaging (MRI). Methods and Materials: From (12(87)) to (10(95)), 22 children were treated with CSI at one institution. All underwent pre-treatment MRI of the spine with Gadolinium as part of their evaluation. The median age was 9 years (range, 31 months to 18 years), and there were 14 males and 8 females. The diagnosis was medulloblastoma in 14 patients, primitive neuroectodermal tumor of the cerebrum in 3, germinoma in 2, pineoblastoma in 1, leptomeningeal gliomatosis in 1 and glioblastoma multiform in 1. All spinal MRIs were reviewed by both neuro radiologist and radiation oncologist to accurately determine the level of thecal sac termination which was obtained by drawing a horizontal line from the lower limit of the spinal theca to the corresponding adjacent vertebral body. Results: The thecal sac termination varied from mid S1 to lower S3. It was located at mid S1 in 1 patient, lower S1 in 3, S1-2 junction in 3, upper S2 in 5, mid S2 in 3, lower S2 in 3, S2-3 junction in 2, upper S3 in 1 and lower S3 in 1. Only (2(22)) patients (9%) had thecal sac terminations below the S2-3 junction. Eight patients had spinal axis involvement and their thecal sac terminations were all above the S2-3 junction. There was no correlation between the level of termination and age, gender or histology. Conclusions: The majority of patients (91%) will have termination of the thecal sac above S3, and therefore placement of the inferior border of the spinal field at the S2-3 junction with a 1 cm caudal margin will be

Water molecule network and active site flexibility of apo protein tyrosine phosphatase 1B

DEFF Research Database (Denmark)

Pedersen, A.K.; Peters, Günther H.J.; Møller, K.B.

2004-01-01

Protein tyrosine phosphatase 1B (PTP1B) plays a key role as a negative regulator of insulin and leptin signalling and is therefore considered to be an important molecular target for the treatment of type 2 diabetes and obesity. Detailed structural information about the structure of PTP1B, including...

SAV1 promotes Hippo kinase activation through antagonizing the PP2A phosphatase STRIPAK

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Bae, Sung Jun [Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, United States; Ni, Lisheng [Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, United States; Osinski, Adam [Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, United States; Tomchick, Diana R. [Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States; Brautigam, Chad A. [Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States; Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, United States; Luo, Xuelian [Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, United States; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States

2017-10-24

The Hippo pathway controls tissue growth and homeostasis through a central MST-LATS kinase cascade. The scaffold protein SAV1 promotes the activation of this kinase cascade, but the molecular mechanisms remain unknown. Here, we discover SAV1-mediated inhibition of the PP2A complex STRIPAKSLMAP as a key mechanism of MST1/2 activation. SLMAP binding to autophosphorylated MST2 linker recruits STRIPAK and promotes PP2A-mediated dephosphorylation of MST2 at the activation loop. Our structural and biochemical studies reveal that SAV1 and MST2 heterodimerize through their SARAH domains. Two SAV1–MST2 heterodimers further dimerize through SAV1 WW domains to form a heterotetramer, in which MST2 undergoes trans-autophosphorylation. SAV1 directly binds to STRIPAK and inhibits its phosphatase activity, protecting MST2 activation-loop phosphorylation. Genetic ablation of SLMAP in human cells leads to spontaneous activation of the Hippo pathway and alleviates the need for SAV1 in Hippo signaling. Thus, SAV1 promotes Hippo activation through counteracting the STRIPAKSLMAP PP2A phosphatase complex.

Suitability of cerebrospinal fluid as a signal-intensity reference on MRI: evaluation of signal-intensity variations in the lumbosacral dural sac

International Nuclear Information System (INIS)

Luoma, E.K.; Luukkonen, R.; Riihimaeki, H.A.; Raininko, R.; Manninen, H.I.; Nummi, P.J.

1997-01-01

The suitability of the cerebrospinal fluid (CSF) in the lumbosacral dural sac as an internal signal-intensity reference was studied on magnetic resonance imaging (MRI) of the lumbar spine using a surface coil and motion artefact suppression technique. A signal-intensity reference is needed when signal is compared between images, studies or subjects. Homogeneity of the CSF was estimated visually on T2-weighted images of 60 subjects at 1.5 T and of another 60 subjects at 0.1 T. Spines with a severely narrowed dural sac or marked scoliosis were excluded from the study to avoid partial volume effect. CSF was homogeneous in 82% and 73% of the examinations at 1.5 T and 0.1 T, respectively. The type and location of the local inhomogeneities did not relate to local narrowings of the dural sac. The signal intensity of CSF was measured in 108 examinations at 0.1 T after correcting the spatially-dependent signal-intensity nonuniformities with a phantom-based method. The signal-intensity difference between the CSF in the upper and lower lumbar dural sac was less than 10% in 73% of the examinations. The CSF in the lumbosacral dural sac can be a useful signal-intensity reference for estimation of the signal of the adjacent structures in patients without severe narrowing of the dural sac or marked scoliosis. It may contribute to assessing spinal disease processes. (orig.). With 1 fig., 3 tabs

Contrast-enhanced MR imaging of the endolymphatic sac in patients with sudden hearing loss

International Nuclear Information System (INIS)

Naganawa, Shinji; Koshikawa, Tokiko; Fukatsu, Hiroshi; Ishigaki, Takeo; Nakashima, Tsutomu; Ichinose, Nobuyasu

2002-01-01

Our objective was to evaluate the frequency of contrast enhancement of the endolymphatic sac in patients with sudden hearing loss. Forty consecutive patients with sudden sensorineural hearing loss (20 males and 20 females; age range 11-82 years), 40 age-matched control subjects, and 5 patients with Meniere's disease were examined using the same imaging protocol on a 1.5-T MR system. Pre- and post-contrast-enhanced T1-weighted 3D spoiled gradient-echo sequence (3D SPGR; TR/TE=23/10 ms, no. of excitations=1, flip angle=30 ) images were obtained using a voxel size of 0.6 x 0.7 x 0.8 mm 3 . Contrast enhancement in the area of the endolymphatic sac was assessed by two radiologists, and the frequency of contrast enhancement was compared between the three study groups. Enhancement of the ipsilateral endolymphatic sac was observed in 30 of the 40 patients with sudden hearing loss (75%). Twenty of these 30 patients also showed enhancement on the contralateral side, and 1 patient showed enhancement only on the contralateral side. Only 1 of the 5 patients with Meniere's disease showed enhancement. Nine of the 40 control subjects (22.5%) showed enhancement (bilateral enhancement in 5 subjects, unilateral in 4). The frequency of enhancement in patients with sudden hearing loss was significantly higher than that in control subjects (P<0.0001) or patients with Meniere's disease (P<0.05). The frequency of contrast enhancement of the endolymphatic sac is significantly increased in patients with sudden hearing loss, but further study is necessary to clarify the relationship between this finding and the pathophysiology of sudden hearing loss. (orig.)

Gene expression demonstrates an immunological capacity of the human endolymphatic sac

DEFF Research Database (Denmark)

Møller, Martin Nue; Kirkeby, Svend; Vikeså, Jonas

2015-01-01

OBJECTIVES/HYPOTHESIS: The purpose of the present study is to explore, demonstrate, and describe the expression of genes related to the innate immune system in the human endolymphatic sac. It is hypothesized that the endolymphatic sac has a significant immunological function in the human inner ear...... was obtained. Multiple key elements of both the cellular and humoral innate immune system were expressed, including Toll-like receptors 4 and 7, as well as beta-defensin and lactoferrin. CONCLUSIONS: The present data provides the first direct evidence of an immunological capacity of the human endolymphatic sac...... immunological entity of the inner ear. LEVEL OF EVIDENCE: N/A....

An anatomic risk model to screen post endovascular aneurysm repair patients for aneurysm sac enlargement.

Science.gov (United States)

Png, Chien Yi M; Tadros, Rami O; Beckerman, William E; Han, Daniel K; Tardiff, Melissa L; Torres, Marielle R; Marin, Michael L; Faries, Peter L

2017-09-01

Follow-up computed tomography angiography (CTA) scans add considerable postimplantation costs to endovascular aneurysm repairs (EVARs) of abdominal aortic aneurysms (AAAs). By building a risk model, we hope to identify patients at low risk for aneurysm sac enlargement to minimize unnecessary CTAs. 895 consecutive patients who underwent EVAR for AAA were reviewed, of which 556 met inclusion criteria. A Probit model was created for aneurysm sac enlargement, with preoperative aneurysm morphology, patient demographics, and operative details as variables. Our final model included 287 patients and had a sensitivity of 100%, a specificity of 68.9%, and an accuracy of 70.4%. Ninety-nine (35%) of patients were assigned to the high-risk group, whereas 188 (65%) of patients were assigned to the low-risk group. Notably, regarding anatomic variables, our model reported that age, pulmonary comorbidities, aortic neck diameter, iliac artery length, and aneurysms were independent predictors of post-EVAR sac enlargement. With the exception of age, all statistically significant variables were qualitatively supported by prior literature. With regards to secondary outcomes, the high-risk group had significantly higher proportions of AAA-related deaths (5.1% versus 1.1%, P = 0.037) and Type 1 endoleaks (9.1% versus 3.2%, P = 0.033). Our model is a decent predictor of patients at low risk for post AAA EVAR aneurysm sac enlargement and associated complications. With additional validation and refinement, it could be applied to practices to cut down on the overall need for postimplantation CTA. Copyright © 2017 Elsevier Inc. All rights reserved.

Fast frequency hopping codes applied to SAC optical CDMA network

Science.gov (United States)

Tseng, Shin-Pin

2015-06-01

This study designed a fast frequency hopping (FFH) code family suitable for application in spectral-amplitude-coding (SAC) optical code-division multiple-access (CDMA) networks. The FFH code family can effectively suppress the effects of multiuser interference and had its origin in the frequency hopping code family. Additional codes were developed as secure codewords for enhancing the security of the network. In considering the system cost and flexibility, simple optical encoders/decoders using fiber Bragg gratings (FBGs) and a set of optical securers using two arrayed-waveguide grating (AWG) demultiplexers (DeMUXs) were also constructed. Based on a Gaussian approximation, expressions for evaluating the bit error rate (BER) and spectral efficiency (SE) of SAC optical CDMA networks are presented. The results indicated that the proposed SAC optical CDMA network exhibited favorable performance.

TCTEX1D4, a novel protein phosphatase 1 interactor: connecting the phosphatase to the microtubule network

Science.gov (United States)

Korrodi-Gregório, Luís; Vieira, Sandra I.; Esteves, Sara L. C.; Silva, Joana V.; Freitas, Maria João; Brauns, Ann-Kristin; Luers, Georg; Abrantes, Joana; Esteves, Pedro J.; da Cruz e Silva, Odete A. B.; Fardilha, Margarida; da Cruz e Silva, Edgar F.

2013-01-01

Summary Reversible phosphorylation plays an important role as a mechanism of intracellular control in eukaryotes. PPP1, a major eukaryotic Ser/Thr-protein phosphatase, acquires its specificity by interacting with different protein regulators, also known as PPP1 interacting proteins (PIPs). In the present work we characterized a physiologically relevant PIP in testis. Using a yeast two-hybrid screen with a human testis cDNA library, we identified a novel PIP of PPP1CC2 isoform, the T-complex testis expressed protein 1 domain containing 4 (TCTEX1D4) that has recently been described as a Tctex1 dynein light chain family member. The overlay assays confirm that TCTEX1D4 interacts with the different spliced isoforms of PPP1CC. Also, the binding domain occurs in the N-terminus, where a consensus PPP1 binding motif (PPP1BM) RVSF is present. The distribution of TCTEX1D4 in testis suggests its involvement in distinct functions, such as TGFβ signaling at the blood–testis barrier and acrosome cap formation. Immunofluorescence in human ejaculated sperm shows that TCTEX1D4 is present in the flagellum and in the acrosome region of the head. Moreover, TCTEX1D4 and PPP1 co-localize in the microtubule organizing center (MTOC) and microtubules in cell cultures. Importantly, the TCTEX1D4 PPP1BM seems to be relevant for complex formation, for PPP1 retention in the MTOC and movement along microtubules. These novel results open new avenues to possible roles of this dynein, together with PPP1. In essence TCTEX1D4/PPP1C complex appears to be involved in microtubule dynamics, sperm motility, acrosome reaction and in the regulation of the blood–testis barrier. PMID:23789093

Platelet alpha-2 adrenergic receptor-mediated phosphoinositide responses in endogenous depression

International Nuclear Information System (INIS)

Mori, Hideki; Koyama, Tsukasa; Yamashita, Itaru

1991-01-01

We have previously indicated that epinephrine stimulates phosphoinositide (PI) hydrolysis by activating alpha-2 adrenergic receptors in human platelets. This method involves the measurement of the accumulation of [ 3 H]-inositol-1-phosphate (IP-1) as an index of Pl hydrolysis; lithium is added to inhibit the metabolism of IP-1, thus giving an enhanced signal. In the present study, we assessed the platelet alpha-2 adrenergic receptor-mediated PI responses in samples from 15 unmedicated patients with endogenous depression and 15 age- and sex-matched control subjects. The responses to epinephrine in the depressed patients were significantly higher than those of the controls, whereas the basal values did not differ significantly. These results support the hypothesis that platelet alpha-2 adrenergic receptors may be supersensitive in patients with endogenous depression

SH2-inositol phosphatase 1 negatively influences early megakaryocyte progenitors.

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Lia E Perez

Full Text Available The SH2-containing-5'inositol phosphatase-1 (SHIP influences signals downstream of cytokine/chemokine receptors that play a role in megakaryocytopoiesis, including thrombopoietin, stromal-cell-derived-Factor-1/CXCL-12 and interleukin-3. We hypothesize that SHIP might control megakaryocytopoiesis through effects on proliferation of megakaryocyte progenitors (MKP and megakaryocytes (MK.Herein, we report the megakaryocytic phenotype and MK functional assays of hematopoietic organs of two strains of SHIP deficient mice with deletion of the SHIP promoter/first exon or the inositol phosphatase domain. Both SHIP deficient strains exhibit a profound increase in MKP numbers in bone marrow (BM, spleen and blood as analyzed by flow cytometry (Lin(-c-Kit+CD41+ and functional assays (CFU-MK. SHIP deficient MKP display increased phosphorylation of Signal Transducers and Activators of Transcription 3 (STAT-3, protein kinase B (PKB/AKT and extracellular signal-regulated kinases (ERKs. Despite increased MKP content, total body number of mature MK (Lin(-c-kit(-CD41+ are not significantly changed as SHIP deficient BM contains reduced MK while spleen MK numbers are increased. Reduction of CXCR-4 expression in SHIP deficient MK may influence MK localization to the spleen instead of the BM. Endomitosis, process involved in MK maturation, was preserved in SHIP deficient MK. Circulating platelets and red blood cells are also reduced in SHIP deficient mice.SHIP may play an important role in regulation of essential signaling pathways that control early megakaryocytopoiesis in vivo.

Pterocarpans with inhibitory effects on protein tyrosine phosphatase 1B from Erythrina lysistemon Hutch

DEFF Research Database (Denmark)

Dao, Trong Tuan; Nguyen, Phi Hung; Thuong, Phuong Thien

2009-01-01

',5':3,4]-2'',2''-dimethyldihydropyrano[6'',5'':9,10]pterocarpan (1), furano[5',4':3,4]-9-hydroxy-10-prenylpterocarpan (2), and 8-formyl-3,9-dihydroxy-4,10-diprenylpterocarpan (3), based on spectroscopic analyses. All the isolates, with the exception of 3, 6, and 11, strongly inhibited protein tyrosine phosphatase 1B (PTP1B) activity...

Studies on the abnormality of embryo sac and pollen fertility in aurotetraploid rice during different growing seasons

International Nuclear Information System (INIS)

Shahid, M.; Jilanfan, S.; Changmin, W.; Peng, Z.; Xiang-dong, X.

2010-01-01

Auto tetraploid rice has a great genetic potential but low seed setting rate is the major encumbrance in its use. Embryo sac fertility and pollen fertility are the most important factors which affect the seed setting rate in auto tetraploid rice. Whole mount eosin B-staining confocal laser scanning microscopy (WE-CLSM) was used to study the fertility and abnormalities in embryo sacs of diploid and auto tetraploid rice during different seasons. The results indicated that the embryo sac fertility (64.5%) was much low in auto tetraploid than that in diploid rice (86%), and five main types of abnormal embryo sac were found in all 10 auto tetraploid rice. Moreover, some other type abnormal embryo sacs were also observed in auto tetraploid rice. Embryo sac without female germ unit and embryo sac degeneration were the most frequent types of abnormalities in auto tetraploid rice. Embryo sac fertility ranged from 49.3% to 79.3%, pollen fertility ranged from 56.2 to 85.9%, and seed setting rate varied from 12.5 to 69.01% in various genotypes of auto tetraploid rice. Embryo sac and pollen fertility were found to have a significant correlation with seed setting rate. Seasons have significant effect on pollen and embryo sac fertility in both type of rice. All the auto tetraploid lines exhibited different types of embryo sac abnormalities which indicated that these might be related to different genotypes. (author)

Loss of the Greatwall Kinase Weakens the Spindle Assembly Checkpoint.

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M Kasim Diril

2016-09-01

Full Text Available The Greatwall kinase/Mastl is an essential gene that indirectly inhibits the phosphatase activity toward mitotic Cdk1 substrates. Here we show that although Mastl knockout (MastlNULL MEFs enter mitosis, they progress through mitosis without completing cytokinesis despite the presence of misaligned chromosomes, which causes chromosome segregation defects. Furthermore, we uncover the requirement of Mastl for robust spindle assembly checkpoint (SAC maintenance since the duration of mitotic arrest caused by microtubule poisons in MastlNULL MEFs is shortened, which correlates with premature disappearance of the essential SAC protein Mad1 at the kinetochores. Notably, MastlNULL MEFs display reduced phosphorylation of a number of proteins in mitosis, which include the essential SAC kinase MPS1. We further demonstrate that Mastl is required for multi-site phosphorylation of MPS1 as well as robust MPS1 kinase activity in mitosis. In contrast, treatment of MastlNULL cells with the phosphatase inhibitor okadaic acid (OKA rescues the defects in MPS1 kinase activity, mislocalization of phospho-MPS1 as well as Mad1 at the kinetochore, and premature SAC silencing. Moreover, using in vitro dephosphorylation assays, we demonstrate that Mastl promotes persistent MPS1 phosphorylation by inhibiting PP2A/B55-mediated MPS1 dephosphorylation rather than affecting Cdk1 kinase activity. Our findings establish a key regulatory function of the Greatwall kinase/Mastl->PP2A/B55 pathway in preventing premature SAC silencing.

Loss of the Greatwall Kinase Weakens the Spindle Assembly Checkpoint.

Science.gov (United States)

Diril, M Kasim; Bisteau, Xavier; Kitagawa, Mayumi; Caldez, Matias J; Wee, Sheena; Gunaratne, Jayantha; Lee, Sang Hyun; Kaldis, Philipp

2016-09-01

The Greatwall kinase/Mastl is an essential gene that indirectly inhibits the phosphatase activity toward mitotic Cdk1 substrates. Here we show that although Mastl knockout (MastlNULL) MEFs enter mitosis, they progress through mitosis without completing cytokinesis despite the presence of misaligned chromosomes, which causes chromosome segregation defects. Furthermore, we uncover the requirement of Mastl for robust spindle assembly checkpoint (SAC) maintenance since the duration of mitotic arrest caused by microtubule poisons in MastlNULL MEFs is shortened, which correlates with premature disappearance of the essential SAC protein Mad1 at the kinetochores. Notably, MastlNULL MEFs display reduced phosphorylation of a number of proteins in mitosis, which include the essential SAC kinase MPS1. We further demonstrate that Mastl is required for multi-site phosphorylation of MPS1 as well as robust MPS1 kinase activity in mitosis. In contrast, treatment of MastlNULL cells with the phosphatase inhibitor okadaic acid (OKA) rescues the defects in MPS1 kinase activity, mislocalization of phospho-MPS1 as well as Mad1 at the kinetochore, and premature SAC silencing. Moreover, using in vitro dephosphorylation assays, we demonstrate that Mastl promotes persistent MPS1 phosphorylation by inhibiting PP2A/B55-mediated MPS1 dephosphorylation rather than affecting Cdk1 kinase activity. Our findings establish a key regulatory function of the Greatwall kinase/Mastl->PP2A/B55 pathway in preventing premature SAC silencing.

Radiographic anatomy of the distal dural SAC

International Nuclear Information System (INIS)

Larsen, J.L.; Olsen, K.O.

1991-01-01

A radio-anatomical study was performed of the distal dural sac (DS) in 121 patients subjected to myelography. In 83.4% the termination of the DS was located from the upper half of the S1-segment to the lower half of the S2-segment. In the remaining patients the dural terminations were more distally located. The average location of the DS-termination was higher than that found in a previous anatomic study. The inference is that in patients with low-back pain and sciatica, the DS tends to terminate at a higher spinal level than in a non-selected anatomic material. The caudal reduction in sagittal diameter of the DS was less than that of the frontal diameter of the sac. The linear diminution in cross-sectional area of the DS from the level of L3 towards the lumbosacral junction was not correlated with the degree of caudal extension of the DS into the sacrum. Thus the length of the DS and its transverse diameters are independent of each other. These results supported the view that the location of the termination of the DS (and hence that of the spinal cord) is not related to stenosis of the central spinal canal. (orig.)

Salicylic acid modulates levels of phosphoinositide dependent-phospholipase C substrates and products to remodel the Arabidopsis suspension cell transcriptome

Directory of Open Access Journals (Sweden)

Eric eRuelland

2014-11-01

Full Text Available Basal phosphoinositide-dependent phospholipase C (PI-PLC activity controls gene expression in Arabidopsis suspension cells and seedlings. PI-PLC catalyzes the production of phosphorylated inositol and diacylglycerol (DAG from phosphoinositides. It is not known how PI-PLC regulates the transcriptome although the action of DAG-kinase (DGK on DAG immediately downstream from PI-PLC is responsible for some of the regulation. We previously established a list of genes whose expression is affected in the presence of PI-PLC inhibitors. Here this list of genes was used as a signature in similarity searches of curated plant hormone response transcriptome data. The strongest correlations obtained with the inhibited PI-PLC signature were with salicylic acid (SA treatments. We confirm here that in Arabidopsis suspension cells SA treatment leads to an increase in phosphoinositides, then demonstrate that SA leads to a significant 20% decrease in phosphatidic acid, indicative of a decrease in PI-PLC products. Previous sets of microarray data were re-assessed. The SA response of one set of genes was dependent on phosphoinositides. Alterations in the levels of a second set of genes, mostly SA-repressed genes, could be related to decreases in PI-PLC products that occur in response to SA action. Together, the two groups of genes comprise at least 40% of all SA-responsive genes. Overall these two groups of genes are distinct in the functional categories of the proteins they encode, their promoter cis-elements and their regulation by DGK or phospholipase D. SA-regulated genes dependent on phosphoinositides are typical SA response genes while those with an SA response that is possibly dependent on PI-PLC products are less SA-specific. We propose a model in which SA inhibits PI-PLC activity and alters levels of PI-PLC products and substrates, thereby regulating gene expression divergently.

Alpha 1-adrenergic receptor-mediated phosphoinositide hydrolysis and prostaglandin E2 formation in Madin-Darby canine kidney cells. Possible parallel activation of phospholipase C and phospholipase A2

International Nuclear Information System (INIS)

Slivka, S.R.; Insel, P.A.

1987-01-01

alpha 1-Adrenergic receptors mediate two effects on phospholipid metabolism in Madin-Darby canine kidney (MDCK-D1) cells: hydrolysis of phosphoinositides and arachidonic acid release with generation of prostaglandin E2 (PGE2). The similarity in concentration dependence for the agonist (-)-epinephrine in eliciting these two responses implies that they are mediated by a single population of alpha 1-adrenergic receptors. However, we find that the kinetics of the two responses are quite different, PGE2 production occurring more rapidly and transiently than the hydrolysis of phosphoinositides. The antibiotic neomycin selectively decreases alpha 1-receptor-mediated phosphatidylinositol 4,5-bisphosphate hydrolysis without decreasing alpha 1-receptor-mediated arachidonic acid release and PGE2 generation. In addition, receptor-mediated inositol trisphosphate formation is independent of extracellular calcium, whereas release of labeled arachidonic acid is largely calcium-dependent. Moreover, based on studies obtained with labeled arachidonic acid, receptor-mediated generation of arachidonic acid cannot be accounted for by breakdown of phosphatidylinositol monophosphate, phosphatidylinositol bisphosphate, or phosphatidic acid. Further studies indicate that epinephrine produces changes in formation or turnover of several classes of membrane phospholipids in MDCK cells. We conclude that alpha 1-adrenergic receptors in MDCK cells appear to regulate phospholipid metabolism by the parallel activation of phospholipase C and phospholipase A2. This parallel activation of phospholipases contrasts with models described in other systems which imply sequential activation of phospholipase C and diacylglycerol lipase or phospholipase A2

Nuclear protein phosphatase-1: an epigenetic regulator of fear memory and amygdala long-term potentiation.

Science.gov (United States)

Koshibu, K; Gräff, J; Mansuy, I M

2011-01-26

Complex brain diseases and neurological disorders in human generally result from the disturbance of multiple genes and signaling pathways. These disturbances may derive from mutations, deletions, translocations or rearrangements of specific gene(s). However, over the past years, it has become clear that such disturbances may also derive from alterations in the epigenome affecting several genes simultaneously. Our work recently demonstrated that epigenetic mechanisms in the adult brain are in part regulated by protein phosphatase 1 (PP1), a protein Ser/Thr phosphatase that negatively regulates hippocampus-dependent long-term memory (LTM) and synaptic plasticity. PP1 is abundant in brain structures involved in emotional processing like the amygdala, it may therefore be involved in the regulation of fear memory, a form of memory related to post-traumatic stress disorder (PTSD) in human. Here, we demonstrate that PP1 is a molecular suppressor of fear memory and synaptic plasticity in the amygdala that can control chromatin remodeling in neurons. We show that the selective inhibition of the nuclear pool of PP1 in amygdala neurons significantly alters posttranslational modifications (PTMs) of histones and the expression of several memory-associated genes. These alterations correlate with enhanced fear memory, and with an increase in long-term potentiation (LTP) that is transcription-dependent. Our results underscore the importance of nuclear PP1 in the amygdala as an epigenetic regulator of emotional memory, and the relevance of protein phosphatases as potential targets for therapeutic treatment of brain disorders like PTSD. © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

PLK1 has tumor-suppressive potential in APC-truncated colon cancer cells.

Science.gov (United States)

Raab, Monika; Sanhaji, Mourad; Matthess, Yves; Hörlin, Albrecht; Lorenz, Ioana; Dötsch, Christina; Habbe, Nils; Waidmann, Oliver; Kurunci-Csacsko, Elisabeth; Firestein, Ron; Becker, Sven; Strebhardt, Klaus

2018-03-16

The spindle assembly checkpoint (SAC) acts as a molecular safeguard in ensuring faithful chromosome transmission during mitosis, which is regulated by a complex interplay between phosphatases and kinases including PLK1. Adenomatous polyposis coli (APC) germline mutations cause aneuploidy and are responsible for familial adenomatous polyposis (FAP). Here we study the role of PLK1 in colon cancer cells with chromosomal instability promoted by APC truncation (APC-ΔC). The expression of APC-ΔC in colon cells reduces the accumulation of mitotic cells upon PLK1 inhibition, accelerates mitotic exit and increases the survival of cells with enhanced chromosomal abnormalities. The inhibition of PLK1 in mitotic, APC-∆C-expressing cells reduces the kinetochore levels of Aurora B and hampers the recruitment of SAC component suggesting a compromised mitotic checkpoint. Furthermore, Plk1 inhibition (RNAi, pharmacological compounds) promotes the development of adenomatous polyps in two independent Apc Min/+ mouse models. High PLK1 expression increases the survival of colon cancer patients expressing a truncated APC significantly.

ABI1 and PP2CA Phosphatases Are Negative Regulators of Snf1-Related Protein Kinase1 Signaling in Arabidopsis

OpenAIRE

Rodrigues, A.; Adamo, M.; Crozet, P.; Margalha, L.; Confraria, A.; Martinho, C.; Elias, A.; Rabissi, A.; Lumbreras, V.; Gonzalez-Guzman, M.; Antoni, R.; Rodriguez, P. L.; Baena-Gonzalez, E.

2013-01-01

Plant survival under environmental stress requires the integration of multiple signaling pathways into a coordinated response, but the molecular mechanisms underlying this integration are poorly understood. Stress-derived energy deprivation activates the Snf1-related protein kinases1 (SnRK1s), triggering a vast transcriptional and metabolic reprogramming that restores homeostasis and promotes tolerance to adverse conditions. Here, we show that two clade A type 2C protein phosphatases (PP2Cs),...

Myeloproliferative disorder FOP-FGFR1 fusion kinase recruits phosphoinositide-3 kinase and phospholipase Cγ at the centrosome

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Tassin Anne-Marie

2008-04-01

Full Text Available Abstract Background The t(6;8 translocation found in rare and agressive myeloproliferative disorders results in a chimeric gene encoding the FOP-FGFR1 fusion protein. This protein comprises the N-terminal region of the centrosomal protein FOP and the tyrosine kinase of the FGFR1 receptor. FOP-FGFR1 is localized at the centrosome where it exerts a constitutive kinase activity. Results We show that FOP-FGFR1 interacts with the large centrosomal protein CAP350 and that CAP350 is necessary for FOP-FGFR1 localisation at centrosome. FOP-FGFR1 activates the phosphoinositide-3 kinase (PI3K pathway. We show that p85 interacts with tyrosine 475 of FOP-FGFR1, which is located in a YXXM consensus binding sequence for an SH2 domain of p85. This interaction is in part responsible for PI3K activation. Ba/F3 cells that express FOP-FGFR1 mutated at tyrosine 475 have reduced proliferative ability. Treatment with PI3K pathway inhibitors induces death of FOP-FGFR1 expressing cells. FOP-FGFR1 also recruits phospholipase Cγ1 (PLCγ1 at the centrosome. We show that this enzyme is recruited by FOP-FGFR1 at the centrosome during interphase. Conclusion These results delineate a particular type of oncogenic mechanism by which an ectopic kinase recruits its substrates at the centrosome whence unappropriate signaling induces continuous cell growth and MPD.

Lithium potentiates GSK-3β activity by inhibiting phosphoinositide 3-kinase-mediated Akt phosphorylation

International Nuclear Information System (INIS)

Tian, Nie; Kanno, Takeshi; Jin, Yu; Nishizaki, Tomoyuki

2014-01-01

Highlights: • Lithium suppresses Akt activity by reducing PI3K-mediated Akt phosphorylation. • Lithium enhances GSK-3β activity by reducing Akt-mediated GSK-3β phosphorylation. • Lithium suppresses GSK-3β activity through its direct inhibition. - Abstract: Accumulating evidence has pointed to the direct inhibitory action of lithium, an anti-depressant, on GSK-3β. The present study investigated further insight into lithium signaling pathways. In the cell-free assay Li 2 CO 3 significantly inhibited phosphoinositide 3-kinase (PI3K)-mediated phosphorylation of Akt1 at Ser473, but Li 2 CO 3 did not affect PI3K-mediated PI(3,4,5)P 3 production and 3-phosphoinositide-dependent protein kinase 1 (PDK1)-mediated phosphorylation of Akt1 at Thr308. This indicates that lithium could enhance GSK-3β activity by suppressing Akt-mediated Ser9 phosphorylation of GSK-3β in association with inhibition of PI3K-mediated Akt activation. There was no direct effect of Li 2 CO 3 on Akt1-induced phosphorylation of GSK-3β at Ser9, but otherwise Li 2 CO 3 significantly reduced GSK-3β-mediated phosphorylation of β-catenin at Ser33/37 and Thr41. This indicates that lithium directly inhibits GSK-3β in an Akt-independent manner. In rat hippocampal slices Li 2 CO 3 significantly inhibited phosphorylation of Akt1/2 at Ser473/474, GSK-3β at Ser9, and β-catenin at Ser33/37 and Thr41. Taken together, these results indicate that lithium exerts its potentiating and inhibiting bidirectional actions on GSK-3β activity

Two PI 3-kinases and one PI 3-phosphatase together establish the cyclic waves of phagosomal PtdIns(3P critical for the degradation of apoptotic cells.

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Nan Lu

2012-01-01

Full Text Available Phosphatidylinositol 3-phosphate (PtdIns(3P is a signaling molecule important for many membrane trafficking events, including phagosome maturation. The level of PtdIns(3P on phagosomes oscillates in two waves during phagosome maturation. However, the physiological significance of such oscillation remains unknown. Currently, the Class III PI 3-kinase (PI3K Vps34 is regarded as the only kinase that produces PtdIns(3P in phagosomal membranes. We report here that, in the nematode C. elegans, the Class II PI3K PIKI-1 plays a novel and crucial role in producing phagosomal PtdIns(3P. PIKI-1 is recruited to extending pseudopods and nascent phagosomes prior to the appearance of PtdIns(3P in a manner dependent on the large GTPase dynamin (DYN-1. PIKI-1 and VPS-34 act in sequence to provide overlapping pools of PtdIns(3P on phagosomes. Inactivating both piki-1 and vps-34 completely abolishes the production of phagosomal PtdIns(3P and disables phagosomes from recruiting multiple essential maturation factors, resulting in a complete arrest of apoptotic-cell degradation. We have further identified MTM-1, a PI 3-phosphatase that antagonizes the activities of PIKI-1 and VPS-34 by down-regulating PtdIns(3P on phagosomes. Remarkably, persistent appearance of phagosomal PtdIns(3P, as a result of inactivating mtm-1, blocks phagosome maturation. Our findings demonstrate that the proper oscillation pattern of PtdIns(3P on phagosomes, programmed by the coordinated activities of two PI3Ks and one PI 3-phosphatase, is critical for phagosome maturation. They further shed light on how the temporally controlled reversible phosphorylation of phosphoinositides regulates the progression of multi-step cellular events.

A mutation in synaptojanin 2 causes progressive hearing loss in the ENU-mutagenised mouse strain Mozart.

Science.gov (United States)

Manji, Shehnaaz S M; Williams, Louise H; Miller, Kerry A; Ooms, Lisa M; Bahlo, Melanie; Mitchell, Christina A; Dahl, Hans-Henrik M

2011-03-15

Hearing impairment is the most common sensory impairment in humans, affecting 1:1,000 births. We have identified an ENU generated mouse mutant, Mozart, with recessively inherited, non-syndromic progressive hearing loss caused by a mutation in the synaptojanin 2 (Synj2), a central regulatory enzyme in the phosphoinositide-signaling cascade. The hearing loss in Mozart is caused by a p.Asn538Lys mutation in the catalytic domain of the inositol polyphosphate 5-phosphatase synaptojanin 2. Within the cochlea, Synj2 mRNA expression was detected in the inner and outer hair cells but not in the spiral ganglion. Synj2(N538K) mutant protein showed loss of lipid phosphatase activity, and was unable to degrade phosphoinositide signaling molecules. Mutant Mozart mice (Synj2(N538K/N538K)) exhibited progressive hearing loss and showed signs of hair cell degeneration as early as two weeks of age, with fusion of stereocilia followed by complete loss of hair bundles and ultimately loss of hair cells. No changes in vestibular or neurological function, or other clinical or behavioral manifestations were apparent. Phosphoinositides are membrane associated signaling molecules that regulate many cellular processes including cell death, proliferation, actin polymerization and ion channel activity. These results reveal Synj2 as a critical regulator of hair cell survival that is essential for hair cell maintenance and hearing function.

Seismic Analysis Code (SAC): Development, porting, and maintenance within a legacy code base

Science.gov (United States)

Savage, B.; Snoke, J. A.

2017-12-01

The Seismic Analysis Code (SAC) is the result of toil of many developers over almost a 40-year history. Initially a Fortran-based code, it has undergone major transitions in underlying bit size from 16 to 32, in the 1980s, and 32 to 64 in 2009; as well as a change in language from Fortran to C in the late 1990s. Maintenance of SAC, the program and its associated libraries, have tracked changes in hardware and operating systems including the advent of Linux in the early 1990, the emergence and demise of Sun/Solaris, variants of OSX processors (PowerPC and x86), and Windows (Cygwin). Traces of these systems are still visible in source code and associated comments. A major concern while improving and maintaining a routinely used, legacy code is a fear of introducing bugs or inadvertently removing favorite features of long-time users. Prior to 2004, SAC was maintained and distributed by LLNL (Lawrence Livermore National Lab). In that year, the license was transferred from LLNL to IRIS (Incorporated Research Institutions for Seismology), but the license is not open source. However, there have been thousands of downloads a year of the package, either source code or binaries for specific system. Starting in 2004, the co-authors have maintained the SAC package for IRIS. In our updates, we fixed bugs, incorporated newly introduced seismic analysis procedures (such as EVALRESP), added new, accessible features (plotting and parsing), and improved the documentation (now in HTML and PDF formats). Moreover, we have added modern software engineering practices to the development of SAC including use of recent source control systems, high-level tests, and scripted, virtualized environments for rapid testing and building. Finally, a "sac-help" listserv (administered by IRIS) was setup for SAC-related issues and is the primary avenue for users seeking advice and reporting bugs. Attempts are always made to respond to issues and bugs in a timely fashion. For the past thirty-plus years

Direct Effects of Microalgae and Protists on Herring (Clupea harengus Yolk Sac Larvae.

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Björn Illing

Full Text Available This study investigated effects of microalgae (Rhodomonas baltica and heterotrophic protists (Oxyrrhis marina on the daily growth, activity, condition and feeding success of Atlantic herring (Clupea harengus larvae from hatch, through the end of the endogenous (yolk sac period. Yolk sac larvae were reared in the presence and absence of microplankton and, each day, groups of larvae were provided access to copepods. Larvae reared with microalgae and protists exhibited precocious (2 days earlier and ≥ 60% increased feeding incidence on copepods compared to larvae reared in only seawater (SW. In the absence and presence of microalgae and protists, life span and growth trajectories of yolk sac larvae were similar and digestive enzyme activity (trypsin and nutritional condition (RNA-DNA ratio markedly declined in all larvae directly after yolk sac depletion. Thus, microplankton promoted early feeding but was not sufficient to alter life span and growth during the yolk sac phase. Given the importance of early feeding, field programs should place greater emphasis on the protozooplankton-ichthyoplankton link to better understand match-mismatch dynamics and bottom-up drivers of year class success in marine fish.

Direct Effects of Microalgae and Protists on Herring (Clupea harengus) Yolk Sac Larvae.

Science.gov (United States)

Illing, Björn; Moyano, Marta; Niemax, Jan; Peck, Myron A

2015-01-01

This study investigated effects of microalgae (Rhodomonas baltica) and heterotrophic protists (Oxyrrhis marina) on the daily growth, activity, condition and feeding success of Atlantic herring (Clupea harengus) larvae from hatch, through the end of the endogenous (yolk sac) period. Yolk sac larvae were reared in the presence and absence of microplankton and, each day, groups of larvae were provided access to copepods. Larvae reared with microalgae and protists exhibited precocious (2 days earlier) and ≥ 60% increased feeding incidence on copepods compared to larvae reared in only seawater (SW). In the absence and presence of microalgae and protists, life span and growth trajectories of yolk sac larvae were similar and digestive enzyme activity (trypsin) and nutritional condition (RNA-DNA ratio) markedly declined in all larvae directly after yolk sac depletion. Thus, microplankton promoted early feeding but was not sufficient to alter life span and growth during the yolk sac phase. Given the importance of early feeding, field programs should place greater emphasis on the protozooplankton-ichthyoplankton link to better understand match-mismatch dynamics and bottom-up drivers of year class success in marine fish.

An unusual feature of yolk sac placentation in Necromys lasiurus (Rodentia, Cricetidae, Sigmodontinae)

DEFF Research Database (Denmark)

Favaron, P O; Carter, Anthony Michael; Mess, A M

2012-01-01

. Elsewhere it was non-villous and closely attached to the uterus. The uterine glands were shallow and wide mouthed. They were associated with vessels and filled with secretion, suggesting the release of histotroph. This feature was absent at later stages. The intimate association of the yolk sac......We studied the development of the inverted yolk sac in a New World rodent, Necromys lasiurus during early placentation. Ten implantation sites were investigated by means of histology, immunohistochemistry and electron microscopy. The yolk sac was villous near its attachment to the placenta...

Distinct antigenic characteristics of murine parietal yolk sac laminin

DEFF Research Database (Denmark)

Wewer, U M; Tichy, D; Damjanov, A

1987-01-01

Two monoclonal antibodies (LAM-A and LAM-B) specific for laminin from normal and neoplastic parietal yolk sac (PYS) cells were produced in rats immunized with a mouse yolk sac carcinoma cell line. Both antibodies immunoprecipitated the 400,000- and 200,000-Da chains of laminin and reacted...... with purified PYS laminin in ELISA. LAM-A reacted with mouse and rat PYS laminin, whereas LAM-B reacted only with mouse PYS laminin. Formaldehyde- and methanol-fixed adult and fetal somatic tissues were immunohistochemically unreactive with either of the two antibodies. In acetone-fixed tissue sections, both...

Laminin, a noncollagenous component of epithelial basement membranes synthesized by a rat yolk sac tumor

DEFF Research Database (Denmark)

Wewer, U; Albrechtsen, R; Ruoslahti, E

1981-01-01

Laminin, a glycoprotein antigenically similar or identical to a component of epithelial basement membranes, was identified as a major component of the abundant extracellular matrix synthesized by an experimentally induced rat yolk sac tumor. Immunocytochemical staining revealed laminin in cultured...... polypeptides with molecular weights of approximately 200,000 and 400,000. These comigrated with the polypeptides of mouse laminin isolated previously. The yolk sac tumor tissue grown in vivo contained laminin in the tumor cells and in the extracellular material as evidenced by immunofluorescence...... membranes in rat tissues in a manner indistinguishable from antilaminin. The presence of laminin in rat yolk sac cells, the presumed origin of our yolk sac tumor, was studied in some detail. Laminin was found to be present in normal cells of the visceral as well as the parietal yolk sac layer...

The dual-specificity phosphatase MKP-1 limits the cardiac hypertrophic response in vitro and in vivo.

Science.gov (United States)

Bueno, O F; De Windt, L J; Lim, H W; Tymitz, K M; Witt, S A; Kimball, T R; Molkentin, J D

2001-01-19

Mitogen-activated protein kinase (MAPK) signaling pathways are important regulators of cell growth, proliferation, and stress responsiveness. A family of dual-specificity MAP kinase phosphatases (MKPs) act as critical counteracting factors that directly regulate the magnitude and duration of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) activation. Here we show that constitutive expression of MKP-1 in cultured primary cardiomyocytes using adenovirus-mediated gene transfer blocked the activation of p38, JNK1/2, and ERK1/2 and prevented agonist-induced hypertrophy. Transgenic mice expressing physiological levels of MKP-1 in the heart showed (1) no activation of p38, JNK1/2, or ERK1/2; (2) diminished developmental myocardial growth; and (3) attenuated hypertrophy in response to aortic banding and catecholamine infusion. These results provide further evidence implicating MAPK signaling factors as obligate regulators of cardiac growth and hypertrophy and demonstrate the importance of dual-specificity phosphatases as counterbalancing regulatory factors in the heart.

The endolymphatic sac: a scanning and transmission electron microscopy study

DEFF Research Database (Denmark)

Qvortrup, Klaus; Bretlau, Poul

2002-01-01

A recent investigation has suggested that the chief cells of the endolymphatic sac produce an endogenous inhibitor of sodium resorption in the kidneys, tentatively named saccin. In the current study, the ultrastructure of the endolymphatic sac and in particular the chief cells are described...... to demonstrate that this organ fulfils the morphological criteria of a potential endocrine gland. Accordingly, the chief cells are shown to exhibit all the organelles and characteristics of cells that simultaneously synthesize, secrete, absorb and digest proteins....

Polarization and EIS studies to evaluate the effect of aluminum concentration on the corrosion behavior of SAC105 solder alloy

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Liyana N. K.

2018-03-01

Full Text Available This paper presents an investigation on corrosion behavior of Sn-1.0Ag-0.5Cu-XAl (X = 0, 0.1, 0.5, 1.0 by means of polarization and electrochemical impedance spectroscopy (EIS measurements in 3.5 wt.% NaCl solution. The results show that addition of aluminum into SAC105 shifts the corrosion current density and passivation current density towards more positive values. It is also found that with an increase in aluminum concentration in SAC105 solder alloy, the corrosion current density increases and polarization resistance decreases. This suggests that SAC105 with the highest concentration of Al has the lowest corrosion resistance. In this case, the corrosion behavior seems to be attributed to anodic dissolution of aluminum and Sn-matrix.

Identification of Open Stomata1-Interacting Proteins Reveals Interactions with Sucrose Non-fermenting1-Related Protein Kinases2 and with Type 2A Protein Phosphatases That Function in Abscisic Acid Responses1[OPEN

Science.gov (United States)

Waadt, Rainer; Manalansan, Bianca; Rauniyar, Navin; Munemasa, Shintaro; Booker, Matthew A.; Brandt, Benjamin; Waadt, Christian; Nusinow, Dmitri A.; Kay, Steve A.; Kunz, Hans-Henning; Schumacher, Karin; DeLong, Alison; Yates, John R.; Schroeder, Julian I.

2015-01-01

The plant hormone abscisic acid (ABA) controls growth and development and regulates plant water status through an established signaling pathway. In the presence of ABA, pyrabactin resistance/regulatory component of ABA receptor proteins inhibit type 2C protein phosphatases (PP2Cs). This, in turn, enables the activation of Sucrose Nonfermenting1-Related Protein Kinases2 (SnRK2). Open Stomata1 (OST1)/SnRK2.6/SRK2E is a major SnRK2-type protein kinase responsible for mediating ABA responses. Arabidopsis (Arabidopsis thaliana) expressing an epitope-tagged OST1 in the recessive ost1-3 mutant background was used for the copurification and identification of OST1-interacting proteins after osmotic stress and ABA treatments. These analyses, which were confirmed using bimolecular fluorescence complementation and coimmunoprecipitation, unexpectedly revealed homo- and heteromerization of OST1 with SnRK2.2, SnRK2.3, OST1, and SnRK2.8. Furthermore, several OST1-complexed proteins were identified as type 2A protein phosphatase (PP2A) subunits and as proteins involved in lipid and galactolipid metabolism. More detailed analyses suggested an interaction network between ABA-activated SnRK2-type protein kinases and several PP2A-type protein phosphatase regulatory subunits. pp2a double mutants exhibited a reduced sensitivity to ABA during seed germination and stomatal closure and an enhanced ABA sensitivity in root growth regulation. These analyses add PP2A-type protein phosphatases as another class of protein phosphatases to the interaction network of SnRK2-type protein kinases. PMID:26175513

A toxin-binding alkaline phosphatase fragment synergizes Bt toxin Cry1Ac against susceptible and resistant Helicoverpa armigera.

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Wenbo Chen

Full Text Available Evolution of resistance by insects threatens the continued success of pest control using insecticidal crystal (Cry proteins from the bacterium Bacillus thuringiensis (Bt in sprays and transgenic plants. In this study, laboratory selection with Cry1Ac yielded five strains of cotton bollworm, Helicoverpa armigera, with resistance ratios at the median lethal concentration (LC50 of activated Cry1Ac ranging from 22 to 1700. Reduced activity and reduced transcription of an alkaline phosphatase protein that binds Cry1Ac was associated with resistance to Cry1Ac in the four most resistant strains. A Cry1Ac-binding fragment of alkaline phosphatase from H. armigera (HaALP1f was not toxic by itself, but it increased mortality caused by Cry1Ac in a susceptible strain and in all five resistant strains. Although synergism of Bt toxins against susceptible insects by toxin-binding fragments of cadherin and aminopeptidase N has been reported previously, the results here provide the first evidence of synergism of a Bt toxin by a toxin-binding fragment of alkaline phosphatase. The results here also provide the first evidence of synergism of a Bt toxin by any toxin-binding peptide against resistant insects.

Application and study of conjunctival sac disinfectants in ophthalmic surgeries

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Yan-Fei Luo

2016-01-01

Full Text Available Postoperative endophthalmitis is the most serious complications of ophthalmic surgeries. Conjunctival sac disinfection is currently recognized as an effectively important way to reduce the risk of endophthalmitis. At present, there are some disinfectants has been used in clinic or in the researches:mercury agent, gentamicin, povidone iodine and acid electrolytic water. All kinds of disinfectants play the role of disinfection by different ways. Povidone iodine is the most widely used conjunctival sac disinfectant. Mercurial and gentamicin have been rarely used because they pollute the environment, are easy to cause drug resistant bacteria, localized side reactions and so on. The acid electrolyte water is not used in clinic at present. With the popularization and development of the ophthalmic surgeries, the ophthalmologists have become more and more concerned about the postoperative eye comfort, the research and application of conjunctival sac disinfectant in the future will continue to be updated and developed.

Auto-inflammatory challenge of the endolymphatic sac - Cochlear damage measured by distortion product oto-acoustic emissions

DEFF Research Database (Denmark)

Larsen, Michael; Friis, Morten; Karlsen, Charlotte Vestrup

2015-01-01

CONCLUSION: Twenty-five rats were challenged by an immunologic attack of the endolymphatic sac. After 6 months, distortion product oto-acoustic emissions (DPOAE) revealed a dysfunction of the outer hair cells and immunological active cells were observed in the endolymphatic sac. This information...... could contribute to the understanding of Ménière's disease. OBJECTIVES: This study investigated if an autoimmune challenge of the endolymphatic sac could affect DPOAE output measurements in rats. Also, a potential autoimmune cell infiltration of the endolymphatic sac was investigated. METHODS: Eighteen...

Phosphatases in Cancer : Shifting the balance

NARCIS (Netherlands)

E. Hoekstra (Elmer)

2015-01-01

markdownabstractAbstract The role of phosphatases in cancer is an ignored research field, mostly based on the dogma that phosphatases function as tumor suppressor genes. However, in our opinion dephosphorylation events by phosphatases can also enhance signaling in cancer. The current research

Baltic salmon (Salmo salar) yolk-sac fry mortality is associated with disturbances in the function of hypoxia-inducible transcription factor (HIF-1α) and consecutive gene expression

International Nuclear Information System (INIS)

Vuori, Kristiina A.M.; Soitamo, Arto; Vuorinen, Pekka J.; Nikinmaa, Mikko

2004-01-01

Baltic salmon (Salmo salar) suffer from abnormally high yolk-sac fry mortality designated as M74-syndrome. In 1990s, 25-80% of salmon females, which ascended rivers to spawn, produced yolk-sac fry suffering from the syndrome. Symptoms of M74-affected fry include neurological disturbances, impaired vascular development and abnormal haemorrhages. The latter symptoms are observed in mammalian embryos if the function of hypoxia inducible transcription factor (HIF-1α), its dimerization partner aryl hydrocarbon nuclear translocator (ARNT) or target gene vascular endothelial growth factor (VEGF) is disturbed. To study the possible involvement of HIF-1α and its target gene VEGF in the development of the syndrome, we collected healthy and M74-affected wild Baltic salmon yolk-sac fry and analyzed HIF-1α mRNA and protein expression, HIF-1α DNA-binding, target gene VEGF protein expression, and blood vessel density in both groups at different stages of yolk-sac fry development. In addition, since Baltic salmon females contain organochlorine contaminants, which have been suggested to be the cause of M74 syndrome via the aryl hydrocarbon receptor (AhR)-dependent gene expression pathway, we studied AhR protein expression, AhR DNA-binding and target gene CYP1A protein expression. Since the parents of both healthy and M74-affected wild fry will have experienced the organochlorine load from the Baltic Sea, hatchery-reared fry were included in the studies as an additional control. The results show that the vascular defects observed in fry suffering from M74 are associated with reduced DNA-binding activity of HIF-1α and subsequent downregulation of its target gene vascular endothelial growth factor (VEGF). In addition, also AhR function is decreased in diseased fry making it unlikely that symptoms of M74-affected fry would be caused by an upregulation of xenobiotically induced AhR-dependent gene expression pathway

Detection of phosphatase activity in aquatic and terrestrial cyanobacterial strains

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Babić Olivera B.

2013-01-01

Full Text Available Cyanobacteria, as highly adaptable microorganisms, are characterized by an ability to survive in different environmental conditions, in which a significant role belongs to their enzymes. Phosphatases are enzymes produced by algae in relatively large quantities in response to a low orthophosphate concentration and their activity is significantly correlated with their primary production. The activity of these enzymes was investigated in 11 cyanobacterial strains in order to determine enzyme synthesis depending on taxonomic and ecological group of cyanobacteria. The study was conducted with 4 terrestrial cyanobacterial strains, which belong to Nostoc and Anabaena genera, and 7 filamentous water cyanobacteria of Nostoc, Oscillatoria, Phormidium and Microcystis genera. The obtained results showed that the activity of acid and alkaline phosphatases strongly depended on cyanobacterial strain and the environment from which the strain originated. Higher activity of alkaline phosphatases, ranging from 3.64 to 85.14 μmolpNP/s/dm3, was recorded in terrestrial strains compared to the studied water strains (1.11-5.96 μmolpNP/s/dm3. The activity of acid phosphatases was higher in most tested water strains (1.67-6.28 μmolpNP/s/dm3 compared to the activity of alkaline phosphatases (1.11-5.96 μmolpNP/s/dm3. Comparing enzyme activity of nitrogen fixing and non-nitrogen fixing cyanobacteria, it was found that most nitrogen fixing strains had a higher activity of alkaline phosphatases. The data obtained in this work indicate that activity of phosphatases is a strain specific property. The results further suggest that synthesis and activity of phosphatases depended on eco-physiological characteristics of the examined cyanobacterial strains. This can be of great importance for the further study of enzymes and mechanisms of their activity as a part of cyanobacterial survival strategy in environments with extreme conditions. [Projekat Ministarstva nauke Republike

The efficacy of sleeve technique in primary nasolacrimal duct obstruction with a high lacrimal sac

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Kyoung-Nam Kim

2014-01-01

Full Text Available Purpose: To evaluate the efficacy of a sleeve technique during endoscopic dacryocystorhinostomy (DCR in primary nasolacrimal duct obstruction (NLDO patients with a high lacrimal sac. Materials and Methods: The medical records of 45 patients (49 cases undergoing endoscopic DCR for primary NLDO with a high lacrimal sac were retrospectively reviewed. In 19 patients (21 cases, the thick maxilla covering the common canalicular opening was removed using a drill and a bicanalicular silicone tube was inserted (group 1. In 26 patients (28 cases, instead of removal of the thick maxilla, a sleeve was inserted into the bicanalicular silicone tube (group 2. At 6 months postoperatively, the success rate was evaluated and the size of the intranasal mucosal ostium was measured. Results: The success rates in group 1 and 2 was 90.5% and 96.4%, respectively (P = 0.400. The intranasal mucosal ostium in group 1 and 2 measured 1.7 ± 0.7 mm and 3.1 ± 1.0 mm, respectively, and the difference was significant (P = 0.042. Conclusions: In primary NLDO patients with a high lacrimal sac, DCR inserting a silicone tube and a sleeve together had a satisfactory success rate without using a drill. In comparison with traditional surgical methods, it helped enlarge the size of the intranasal mucosal ostium.

Expression, prognostic significance and mutational analysis of protein tyrosine phosphatase SHP-1 in chronic myeloid leukemia.

Science.gov (United States)

Papadopoulou, Vasiliki; Kontandreopoulou, Elina; Panayiotidis, Panayiotis; Roumelioti, Maria; Angelopoulou, Maria; Kyriazopoulou, Lydia; Diamantopoulos, Panagiotis T; Vaiopoulos, George; Variami, Eleni; Kotsianidis, Ioannis; Athina Viniou, Nora

2016-05-01

The protein tyrosine phosphatase SHP-1 dephosphorylates BCR-ABL1, thereby serving as a potential control mechanism of BCR-ABL1 kinase activity. Pathways regulating SHP-1 expression, which could be exploited in the therapeutics of TKI-resistant chronic myeloid leukemia (CML), remain unknown. Moreover, the questions of whether there is any kind of SHP-1 deregulation in CML, contributing to disease initiation or evolution, as well as the question of prognostic significance of SHP-1, have not been definitively answered. This study shows moderately lower SHP-1 mRNA expression in chronic phase CML patients in comparison to healthy individuals and no change in SHP-1 mRNA levels after successful TKI treatment. Mutational analysis of the aminoterminal and phosphatase domains of SHP-1 in patients did not reveal genetic lesions. This study also found no correlation of SHP-1 expression at diagnosis with response to treatment, although a trend for lower SHP-1 expression was noted in the very small non-responders' group of the 3-month therapeutic milestone.

WIP1 phosphatase as pharmacological target in cancer therapy

Czech Academy of Sciences Publication Activity Database

Pecháčková, Soňa; Burdová, Kamila; Macůrek, Libor

2017-01-01

Roč. 95, č. 6 (2017), s. 589-599 ISSN 0946-2716 R&D Projects: GA MŠk 7F14061; GA MŠk LO1220 Institutional support: RVO:68378050 Keywords : Cancer * Phosphatase * Checkpoint * DNA damage response * Inhibitor * p53 Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Medicinal chemistry Impact factor: 4.686, year: 2016

Interaction with phosphoinositides confers adaptation onto the TRPV1 pain receptor.

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Jing Yao

2009-02-01

Full Text Available Adaptation is a common feature of many sensory systems. But its occurrence to pain sensation has remained elusive. Here we address the problem at the receptor level and show that the capsaicin ion channel TRPV1, which mediates nociception at the peripheral nerve terminals, possesses properties essential to the adaptation of sensory responses. Ca(2+ influx following the channel opening caused a profound shift (approximately 14-fold of the agonist sensitivity, but did not alter the maximum attainable current. The shift was adequate to render the channel irresponsive to normally saturating concentrations, leaving the notion that the channel became no longer functional after desensitization. By simultaneous patch-clamp recording and total internal reflection fluorescence (TIRF imaging, it was shown that the depletion of phosphatidylinositol 4,5-bisphosphate (PIP2 induced by Ca(2+ influx had a rapid time course synchronous to the desensitization of the current. The extent of the depletion was comparable to that by rapamycin-induced activation of a PIP2 5-phosphatase, which also caused a significant reduction of the agonist sensitivity without affecting the maximum response. These results support a prominent contribution of PIP2 depletion to the desensitization of TRPV1 and suggest the adaptation as a possible physiological function for the Ca(2+ influx through the channel.

Ultrastructure of endothelium in ovules of Penstemon gentianoides Poir. (Scrophulariaceae) at mature embryo sac phase.

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Dane, Feruzan; Olgun, Göksel; Ekici, Nuran

2007-06-01

In this study ultrastructural differences between endothelial cells of different location in Penstemon gentianoides have been examined with electron microscope at mature embryo sac phase. Embryo sac is of the Polygonum type and surrounded by endothelium except the micropylar region. The cuticle is located primarily around the chalazal three-fourths of the embryo sac. Endothelium cells around the chalaza and toward the micropylar region are rich in cytoplasmic organelles. The cytoplasm of endothelial cells near the central cell has large vacuoles and few organelles. There are also plasmodesmas on the anticlinal walls of endothelial cells. The endothelium and the micropylar integumentary cells play a role in transport of metabolites into the embryo sac.

Development of SAC-OCDMA in FSO with multi-wavelength laser source

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Moghaddasi, Majid; Mamdoohi, Ghazaleh; Muhammad Noor, Ahmad Shukri; Mahdi, Mohd Adzir; Ahmad Anas, Siti Barirah

2015-12-01

We propose and demonstrate a free space optical network, based on spectral amplitude coding optical code division multiple access (SAC-OCDMA) with a multi-wavelength laser source. A detailed theoretical analysis that represents the characteristics of SAC-OCDMA system was developed. In addition to the impact of turbulence, influences of several system noises such as optical beat interference (OBI), relative intensity noise, and receiver noises, have been studied. From the numerical results, it was found that the influence of OBI is more dominant, especially at higher received power. Two different codes, namely, modified quadratic congruence and modified double weight, are then compared with the latter which provides better performance. A transmission distance of 2.6 km with 10 users and an 8 cm aperture diameter is advisable whenever the turbulence is moderate. These results can be improved when a beam divergence smaller than 1 mrad is utilized.

COMPARISON OF METHODS FOR ALKALINE PHOSPHATASE AND PEROXIDASE DETECTION IN MILK

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felipe Nael Seixas

2014-02-01

Full Text Available This study evaluated the performance of strips for colorimetric detection of alkaline phosphatase and peroxidase in milk, comparing them with a kit of reagents for alkaline phosphatase and the official methodology for peroxidase. The samples were analyzed at the Laboratory Inspection of Products of Animal Origin, State University of Londrina. For the comparison tests for the detection of alkaline phosphatase four treatments were made by adding different percentages of raw milk (1%, 2%, 5% and 10% in the pasteurized milk, plus two control treatments. Thirty-eight samples triplicate for each treatment were analyzed. To compare the performance of tests for peroxidase 80 pasteurized milk samples were evaluated simultaneously by official methodology and by colorimetric strips. The performance of the alkaline phosphatase were different for the treatments with 1% and 2% of raw milk which had all the strips change color as the reagent kit showed the presence of phosphatase in just 2.63% and 5.26% the cases, respectively for each treatment. The colorimetric strips for alkaline phosphatase are more sensitive for the identification of small quantities compared to the reagent kit. The performance of tests for peroxidase showed no difference. The strips for the detection of peroxidase or alkaline phosphatase were effective and can replace traditional methods.

Role of phosphoinositide 3-kinase in ischemic postconditioning-induced attenuation of cerebral ischemia-evoked behavioral deficits in mice.

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Rehni, Ashish K; Singh, Nirmal

2007-01-01

The present study has been designed to pharmacologically investigate the role of phosphoinositide 3-kinase in ischemic postconditioning-induced reversal of global cerebral ischemia and reperfusion-induced behavioral dysfunction in mice. Bilateral carotid artery occlusion for 10 min followed by reperfusion for 24 h was employed in the present study to produce ischemia and reperfusion-induced cerebral injury in mice. Short-term memory was evaluated using the elevated plus maze test. The inclined beam walking test was employed to assess motor incoordination. Bilateral carotid artery occlusion followed by reperfusion produced impaired short-term memory, motor co-ordination and lateral push response. Three episodes of carotid artery occlusion for a period of 10 s and reperfusion of 10 s (ischemic postconditioning) significantly prevented ischemia-reperfusion-induced behavioral deficit measured in terms of loss of short-term memory, motor coordination and lateral push response. Wortmannin (2 mg/kg, iv), a phosphoinositide 3-kinase inhibitor given 10 min before ischemia attenuated the beneficial effects of ischemic postconditioning. It may be concluded that beneficial effects of ischemic postconditioning on global cerebral ischemia and reperfusion-induced behavioral deficits may involve activation of phosphoinositide 3-kinase-linked pathway.

[Lacrimal sac tumors presenting as lacrimal obstruction. Retrospective study in Mexican patients 2007-2012].

Science.gov (United States)

Coloma-González, I; Flores-Preciado, J; Ceriotto, A; Corredor-Casas, S; Salcedo-Casillas, G

2014-06-01

To determine the demographic and clinical data of primary tumors of the lacrimal sac presenting as lacrimal obstruction. Retrospective and descriptive study was conducted between the years 2007 to 2012 on all patients undergoing surgery for low lacrimal obstruction at Dr. Luis Sanchez Bulnes Hospital, an Association for the prevention of blindness in Mexico IAP. Primary tumors of the lacrimal sac represented 2.5% of all lacrimal obstructions, being more common in women than in men (8:1). The large majority (89%) of the cases were non-epithelial, with lymphoid lesions being the most frequent. Benign tumors were presented at a younger age (50 years old) than malignant (70 years old). One-third (33%) of cases were unexpected findings during surgery (100% benign). Just over half (55%) were malignant tumors (1.4% of obstructions), all of them lymphoproliferative lesions. The most frequent clinical tumor was in the inner edge, either with or without epiphora. The progression time varied according to the degree of aggressiveness of the lymphoma (3 months-10 years). Lacrimal sac tumors are rare, but they must be taken into account in patients with an unusual clinical presentation of lacrimal obstruction. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

Anatomy and histology of the newly discovered adipose sac structure within the labia majora: international original research.

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Ostrzenski, Adam; Krajewski, Pawel; Davis, Kern

2016-09-01

To determine whether there is any new anatomical structure present within the labia majora. A case serial study was executed on eleven consecutive fresh human female cadavers. Stratum-by-stratum dissections of the labia majora were performed. Twenty-two anatomic dissections of labia majora were completed. Eosin and Hematoxylin agents were used to stain newly discovered adipose sac's tissues of the labia majora and the cylinder-like structures, which cover condensed adipose tissues. The histology of these two structures was compared. All dissected labia majora demonstrated the presence of the anatomic existence of the adipose sac structure. Just under the dermis of the labia majora, the adipose sac was located, which was filled with lobules containing condensed fatty tissues in the form of cylinders. The histological investigation established that the well-organized fibro-connective-adipose tissues represented the adipose sac. The absence of descriptions of the adipose sac within the labia majora in traditional anatomic and gynecologic textbooks was noted. In this study group, the newly discovered adipose sac is consistently present within the anatomical structure of the labia majora. The well-organized fibro-connective-adipose tissue represents microscopic characteristic features of the adipose sac.

INPP5E Preserves Genomic Stability through Regulation of Mitosis.

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Sierra Potchanant, Elizabeth A; Cerabona, Donna; Sater, Zahi Abdul; He, Ying; Sun, Zejin; Gehlhausen, Jeff; Nalepa, Grzegorz

2017-03-15

The partially understood phosphoinositide signaling cascade regulates multiple aspects of cellular metabolism. Previous studies revealed that INPP5E, the inositol polyphosphate-5-phosphatase that is mutated in the developmental disorders Joubert and MORM syndromes, is essential for the function of the primary cilium and maintenance of phosphoinositide balance in nondividing cells. Here, we report that INPP5E further contributes to cellular homeostasis by regulating cell division. We found that silencing or genetic knockout of INPP5E in human and murine cells impairs the spindle assembly checkpoint, centrosome and spindle function, and maintenance of chromosomal integrity. Consistent with a cell cycle regulatory role, we found that INPP5E expression is cell cycle dependent, peaking at mitotic entry. INPP5E localizes to centrosomes, chromosomes, and kinetochores in early mitosis and shuttles to the midzone spindle at mitotic exit. Our findings identify the previously unknown, essential role of INPP5E in mitosis and prevention of aneuploidy, providing a new perspective on the function of this phosphoinositide phosphatase in health and development. Copyright © 2017 Sierra Potchanant et al.

Sporadic Endolymphatic Sac Tumor-A Very Rare Cause of Hearing Loss, Tinnitus, and Dizziness

DEFF Research Database (Denmark)

Schnack, Didde Trærup; Kiss, Katalin; Hansen, Søren

2017-01-01

Sporadic endolymphatic sac tumor is a very rare neoplasm. It is low malignant, locally destructive and expansive, but non-metastasizing. The tumor is very rare in the sporadic form, but more often associated with Von Hippel-Lindau disease. A 65-year old man with left sided tinnitus and hearing loss......-operative freeze-microscopy showed inflammation tissue, whereas subsequent microscopy showed papillary-cystic endolymphatic sac tumor. Endolymphatic sac tumor is a rare neoplasm. The tumor may present with asymmetrically sensory neural hearing loss with or without tinnitus, dizziness and facial nerve paresis...

HD-PTP is a catalytically inactive tyrosine phosphatase due to a conserved divergence in its phosphatase domain.

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Marie-Claude Gingras

Full Text Available The HD-PTP protein has been described as a tumor suppressor candidate and based on its amino acid sequence, categorized as a classical non-transmembrane protein tyrosine phosphatase (PTP. To date, no HD-PTP phosphorylated substrate has been identified and controversial results concerning its catalytic activity have been recently reported.Here we report a rigorous enzymatic analysis demonstrating that the HD-PTP protein does not harbor tyrosine phosphatase or lipid phosphatase activity using the highly sensitive DiFMUP substrate and a panel of different phosphatidylinositol phosphates. We found that HD-PTP tyrosine phosphatase inactivity is caused by an evolutionary conserved amino acid divergence of a key residue located in the HD-PTP phosphatase domain since its back mutation is sufficient to restore the HD-PTP tyrosine phosphatase activity. Moreover, in agreement with a tumor suppressor activity, HD-PTP expression leads to colony growth reduction in human cancer cell lines, independently of its catalytic PTP activity status.In summary, we demonstrate that HD-PTP is a catalytically inactive protein tyrosine phosphatase. As such, we identify one residue involved in its inactivation and show that its colony growth reduction activity is independent of its PTP activity status in human cancer cell lines.

Intravesicular Phosphatase PHOSPHO1 Function in Enamel Mineralization and Prism Formation

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Mirali Pandya

2017-10-01

Full Text Available The transport of mineral ions from the enamel organ-associated blood vessels to the developing enamel crystals involves complex cargo packaging and carriage mechanisms across several cell layers, including the ameloblast layer and the stratum intermedium. Previous studies have established PHOSPHO1 as a matrix vesicle membrane-associated phosphatase that interacts with matrix vesicles molecules phosphoethanolamine and phosphocholine to initiate apatite crystal formation inside of matrix vesicles in bone. In the present study, we sought to determine the function of Phospho1 during amelogenesis. PHOSPHO1 protein localization during amelogenesis was verified using immunohistochemistry, with positive signals in the enamel layer, ameloblast Tomes' processes, and in the walls of ameloblast secretory vesicles. These ameloblast secretory vesicle walls were also labeled for amelogenin and the exosomal protein marker HSP70 using immunohistochemistry. Furthermore, PHOSPHO1 presence in the enamel organ was confirmed by Western blot. Phospho1−/− mice lacked sharp incisal tips, featured a significant 25% increase in total enamel volume, and demonstrated a significant 2-fold reduction in silver grain density of von Kossa stained ground sections indicative of reduced mineralization in the enamel layer when compared to wild-type mice (p < 0.001. Scanning electron micrographs of Phospho1−/− mouse enamel revealed a loss of the prominent enamel prism “picket fence” structure, a loss of parallel crystal organization within prisms, and a 1.56-fold increase in enamel prism width (p < 0.0001. Finally, EDS elemental analysis demonstrated a significant decrease in phosphate incorporation in the enamel layer when compared to controls (p < 0.05. Together, these data establish that the matrix vesicle membrane-associated phosphatase PHOSPHO1 is essential for physiological enamel mineralization. Our findings also suggest that intracellular ameloblast secretory

Innate immune defense in the inner ear - mucines are expressed by the human endolymphatic sac

DEFF Research Database (Denmark)

Møller, Martin N; Kirkeby, Svend; Cayé-Thomasen, Per

2017-01-01

The human endolymphatic sac has been shown recently to have immunological capacities and has thus been proposed as the main entity protecting the inner ear from pathogen invasion, equivalent to mucosa-associated lymphoid tissue (MALT). Although the sac expresses molecules of the innate immune...... system, the potential expression of members of the important mucin family has not been detailed. Thus, this paper explores endolymphatic sac expression of a number of mucins and mucin precursors. Twelve fresh tissue samples from the human endolymphatic sac were obtained during translabyrinthine surgery...... immunological tissue structure of the inner ear, equivalent to MALT in other organs. The mucins may also play a role in the formation and continuous homeostasis of the inner ear fluids, as well as the pathogenesis of Meniere's disease....

Spectral Amplitude Coding (SAC)-OCDMA Network with 8DPSK

Science.gov (United States)

Aldhaibani, A. O.; Aljunid, S. A.; Fadhil, Hilal A.; Anuar, M. S.

2013-09-01

Optical code division multiple access (OCDMA) technique is required to meet the increased demand for high speed, large capacity communications in optical networks. In this paper, the transmission performance of a spectral amplitude coding (SAC)-OCDMA network is investigated when a conventional single-mode fiber (SMF) is used as the transmission link using 8DPSK modulation. The DW has a fixed weight of two. Simulation results reveal that the transmission distance is limited mainly by the fiber dispersion when high coding chip rate is used. For a two-user SAC-OCDMA network operating with 2 Gbit/s data rate and two wavelengths for each user, the maximum allowable transmission distance is about 15 km.

Crystallization of a newly discovered histidine acid phosphatase from Francisella tularensis

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Felts, Richard L. [Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211 (United States); Reilly, Thomas J. [Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri-Columbia, Columbia, Missouri 65212 (United States); Veterinary Medical Diagnostic Laboratory, College of Veterinary Medicine, University of Missouri-Columbia, Columbia, Missouri 65212 (United States); Calcutt, Michael J. [Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri-Columbia, Columbia, Missouri 65212 (United States); Tanner, John J., E-mail: tannerjj@missouri.edu [Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211 (United States); Department of Biochemistry, University of Missouri-Columbia, Columbia, Missouri 65211 (United States)

2006-01-01

A histidine acid phosphatase from the CDC Category A pathogen F. tularensis has been crystallized in space group P4{sub 1}2{sub 1}2, with unit-cell parameters a = 61.96, c = 210.78 Å. A 1.75 Å resolution data set was collected at Advanced Light Source beamline 4.2.2. Francisella tularensis is a highly infectious bacterial pathogen that is considered by the Centers for Disease Control and Prevention to be a potential bioterrorism weapon. Here, the crystallization of a 37.2 kDa phosphatase encoded by the genome of F. tularensis subsp. holarctica live vaccine strain is reported. This enzyme shares 41% amino-acid sequence identity with Legionella pneumophila major acid phosphatase and contains the RHGXRXP motif that is characteristic of the histidine acid phosphatase family. Large diffraction-quality crystals were grown in the presence of Tacsimate, HEPES and PEG 3350. The crystals belong to space group P4{sub 1}2{sub 1}2, with unit-cell parameters a = 61.96, c = 210.78 Å. The asymmetric unit is predicted to contain one protein molecule, with a solvent content of 53%. A 1.75 Å resolution native data set was recorded at beamline 4.2.2 of the Lawrence Berkeley National Laboratory Advanced Light Source. Molecular-replacement trials using the human prostatic acid phosphatase structure as the search model (28% amino-acid sequence identity) did not produce a satisfactory solution. Therefore, the structure of F. tularensis histidine acid phosphatase will be determined by multiwavelength anomalous dispersion phasing using a selenomethionyl derivative.

Crystallization of a newly discovered histidine acid phosphatase from Francisella tularensis

International Nuclear Information System (INIS)

Felts, Richard L.; Reilly, Thomas J.; Calcutt, Michael J.; Tanner, John J.

2005-01-01

A histidine acid phosphatase from the CDC Category A pathogen F. tularensis has been crystallized in space group P4 1 2 1 2, with unit-cell parameters a = 61.96, c = 210.78 Å. A 1.75 Å resolution data set was collected at Advanced Light Source beamline 4.2.2. Francisella tularensis is a highly infectious bacterial pathogen that is considered by the Centers for Disease Control and Prevention to be a potential bioterrorism weapon. Here, the crystallization of a 37.2 kDa phosphatase encoded by the genome of F. tularensis subsp. holarctica live vaccine strain is reported. This enzyme shares 41% amino-acid sequence identity with Legionella pneumophila major acid phosphatase and contains the RHGXRXP motif that is characteristic of the histidine acid phosphatase family. Large diffraction-quality crystals were grown in the presence of Tacsimate, HEPES and PEG 3350. The crystals belong to space group P4 1 2 1 2, with unit-cell parameters a = 61.96, c = 210.78 Å. The asymmetric unit is predicted to contain one protein molecule, with a solvent content of 53%. A 1.75 Å resolution native data set was recorded at beamline 4.2.2 of the Lawrence Berkeley National Laboratory Advanced Light Source. Molecular-replacement trials using the human prostatic acid phosphatase structure as the search model (28% amino-acid sequence identity) did not produce a satisfactory solution. Therefore, the structure of F. tularensis histidine acid phosphatase will be determined by multiwavelength anomalous dispersion phasing using a selenomethionyl derivative

Effects of SOV-induced phosphatase inhibition and expression of protein tyrosine phosphatases in rat corneal endothelial cells.

Science.gov (United States)

Chen, Wei-Li; Harris, Deshea L; Joyce, Nancy C

2005-11-01

Contact inhibition is an important mechanism for maintaining corneal endothelium in a non-replicative state. Protein tyrosine phosphatases (PTPs) play a role in regulating the integrity of cell-cell contacts, differentiation, and growth. In this study, we aimed to evaluate whether phosphatases are involved in the maintenance of contact-dependent inhibition of proliferation in corneal endothelial cells and to identify candidate PTPs that are expressed in these cells and might be involved in regulation of contact inhibition. Confluent cultures of rat corneal endothelial cells or endothelium in ex vivo corneas were treated with the general phosphatase inhibitor, sodium orthovanadate (SOV). Immunocytochemistry (ICC) evaluated the effect of SOV on cell-cell contacts by staining for ZO-1, and on cell cycle progression by staining for Ki67. Transverse sections of rat cornea and cultured rat corneal endothelial cells were used to test for expression of the candidate PTPs: PTP-mu, PTP-LAR, PTP1B, SHP-1, SHP-2, and PTEN using ICC and either Western blots or RT-PCR. ZO-1 staining demonstrated that SOV induced a time-dependent release of cell-cell contacts in confluent cultures of corneal endothelial cells and in the endothelium of ex vivo corneas. Staining for Ki67 indicated that SOV promoted limited cell cycle progression in the absence of serum. PTP-mu, PTP1B, SHP-1, SHP-2, and PTEN, but not PTP-LAR, were expressed in rat corneal endothelial cells in situ and in culture. The subcellular location of PTP-mu and PTP1B differed in subconfluent and confluent cells, while that of SHP-1, SHP-2, and PTEN was similar, regardless of confluent status. Western blots confirmed the expression of PTP1B, SHP-1, SHP-2, and PTEN. RT-PCR confirmed expression of PTP-mu mRNA. Phosphatases are involved in regulation of junctional integrity and of cell proliferation in corneal endothelial cells. PTP-mu, PTP1B, SHP-1, SHP-2, and PTEN are expressed in rat corneal endothelium and may be involved in

Lymph flux rates from various lymph sacs in the cane toad Rhinella marina: an experimental evaluation of the roles of compliance, skeletal muscles and the lungs in the movement of lymph.

Science.gov (United States)

Hillman, Stanley S; Hedrick, Michael S; Drewes, Robert C; Withers, Philip C

2010-09-15

A new method for quantitatively determining lymph flux from various lymphatic sacs of an anuran, the cane toad, was developed. This method used the dye dilution principle of C(i)V(i)=C(f)V(f) following injection of Evans Blue into specific lymph sacs and measuring its appearance in the venous circulation. The apparent lymph volume was 57 ml kg(-1). The greatest rate of lymph return (0.5-0.8 ml kg(-1) min(-1)) and best linear fit of Evans Blue appearance in the circulation with time followed injections into the subvertebral lymph sac, which has direct connections to both the anterior and posterior pairs of lymphatic hearts. Rate of lymph flux from the pair of posterior lymph hearts was three times greater than the anterior pair. Rates of lymph flux were only influenced by injection volume in the crural lymph sacs, implicating lymph sac compliance as the source of the pressure for lymph movement from these sacs. Femoral lymph sac fluxes were decreased by 60% following ablation of the tendons of the sphincter ani cloacalis, abdominal crenators and piriformis. This supports a role for these muscles in generating the pressure for vertical lymph movement. Femoral lymph sac fluxes were also decreased by 70% by the insertion of a coil in the subvertebral lymph sac, preventing normal compression and expansion of this sac by the lungs. This supports a role for lung ventilation in generating the pressure for vertical movement of lymph. Contrary to previous hypotheses, fluxes from the brachial sac were not influenced by insertion of the coil into the subvertebral sac. A haemorrhage equivalent to 50% of the blood volume did not change lymph flux rates from the femoral lymph sacs. These data provide the first experimental evidence that actual lymph fluxes in the cane toad Rhinella marina depend on lymph sac compliance, contraction of specific skeletal muscles and lung ventilation to move lymph laterally and vertically to the dorsally located lymphatic hearts.

Rapamycin causes activation of protein phosphatase-2A1 and nuclear translocation of PCNA in CD4+ T cells

International Nuclear Information System (INIS)

Morrow, Peter W.; Tung, H.Y. Lim; Hemmings, Hugh C.

2004-01-01

Rapamycin is a powerful immunosuppressant that causes cell cycle arrest in T cells and several other cell types. Despite its important clinical role, the mechanism of action of rapamycin is not fully understood. Here, we show that rapamycin causes the activation of protein phosphatase-2A 1 which forms a complex with proliferation cell nuclear antigen (PCNA) in a CD 4+ T cell line. Rapamycin also induces PCNA translocation from the cytoplasm to the nucleus, an effect which is antagonized by okadaic acid, an inhibitor of type 2A protein phosphatases. These findings provide evidence for the existence of a signal transduction pathway that links a rapamycin-activated type 2A protein phosphatase to the control of DNA synthesis, DNA repair, cell cycle, and cell death via PCNA

Solutions Network Formulation Report. Reducing Light Pollution in U.S. Coastal Regions Using the High Sensitivity Cameras on the SAC-C and Aquarius/SAC-D Satellites

Science.gov (United States)

Andrews, Jane C.; Knowlton, Kelly

2007-01-01

Light pollution has significant adverse biological effects on humans, animals, and plants and has resulted in the loss of our ability to view the stars and planets of the universe. Over half of the U.S. population resides in coastal regions where it is no longer possible to see the stars and planets in the night sky. Forty percent of the entire U.S. population is never exposed to conditions dark enough for their eyes to convert to night vision capabilities. In coastal regions, urban lights shine far out to sea where they are augmented by the output from fishing boat, cruise ship and oil platform floodlights. The proposed candidate solution suggests using HSCs (high sensitivity cameras) onboard the SAC-C and Aquarius/SAC-D satellites to quantitatively evaluate light pollution at high spatial resolution. New products modeled after pre-existing, radiance-calibrated, global nighttime lights products would be integrated into a modified Garstang model where elevation, mountain screening, Rayleigh scattering, Mie scattering by aerosols, and atmospheric extinction along light paths and curvature of the Earth would be taken into account. Because the spatial resolution of the HSCs on SAC-C and the future Aquarius/SAC-D missions is greater than that provided by the DMSP (Defense Meteorological Satellite Program) OLS (Operational Linescan System) or VIIRS (Visible/Infrared Imager/Radiometer Suite), it may be possible to obtain more precise light intensity data for analytical DSSs and the subsequent reduction in coastal light pollution.

Role of Zinc and Magnesium Ions in the Modulation of Phosphoryl Transfer in Protein Tyrosine Phosphatase 1B.

Science.gov (United States)

Bellomo, Elisa; Abro, Asma; Hogstrand, Christer; Maret, Wolfgang; Domene, Carmen

2018-03-28

While the majority of phosphatases are metalloenzymes, the prevailing model for the reactions catalyzed by protein tyrosine phosphatases does not involve any metal ion, yet both metal cations and oxoanions affect their enzymatic activity. Mg 2+ and Zn 2+ activate and inhibit, respectively, protein tyrosine phosphatase 1B (PTP1B). Molecular dynamics simulations, metadynamics, and quantum chemical calculations in combination with experimental investigations demonstrate that Mg 2+ and Zn 2+ compete for the same binding site in the active site only in the closed conformation of the enzyme in its phosphorylated state. The two cations have different effects on the arrangements and activities of water molecules that are necessary for the hydrolysis of the phosphocysteine intermediate in the second catalytic step of the reaction. Remarkable differences between the established structural enzymology of PTP1B investigated ex vivo and the function of PTP1B in vivo become evident. Different reaction pathways are viable when the presence of metal ions and their cellular concentrations are considered. The findings suggest that the substrate delivers the inhibitory Zn 2+ ion to the active site. The inhibition and activation can be ascribed to the different coordination chemistries of Zn 2+ and Mg 2+ ions and the orientation of the metal-coordinated water molecules. Metallochemistry adds an additional dimension to the regulation of PTP1B and presumably other members of this enzyme family.

Mitogen-activated protein kinase phosphatase 1 (MKP-1) in macrophage biology and cardiovascular disease. A redox-regulated master controller of monocyte function and macrophage phenotype.

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Kim, Hong Seok; Asmis, Reto

2017-08-01

MAPK pathways play a critical role in the activation of monocytes and macrophages by pathogens, signaling molecules and environmental cues and in the regulation of macrophage function and plasticity. MAPK phosphatase 1 (MKP-1) has emerged as the main counter-regulator of MAPK signaling in monocytes and macrophages. Loss of MKP-1 in monocytes and macrophages in response to metabolic stress leads to dysregulation of monocyte adhesion and migration, and gives rise to dysfunctional, proatherogenic monocyte-derived macrophages. Here we review the properties of this redox-regulated dual-specificity MAPK phosphatase and the role of MKP-1 in monocyte and macrophage biology and cardiovascular diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

Standardization and validation of a novel and simple method to assess lumbar dural sac size

International Nuclear Information System (INIS)

Daniels, M.L.A.; Lowe, J.R.; Roy, P.; Patrone, M.V.; Conyers, J.M.; Fine, J.P.; Knowles, M.R.; Birchard, K.R.

2015-01-01

Aim: To develop and validate a simple, reproducible method to assess dural sac size using standard imaging technology. Materials and methods: This study was institutional review board-approved. Two readers, blinded to the diagnoses, measured anterior–posterior (AP) and transverse (TR) dural sac diameter (DSD), and AP vertebral body diameter (VBD) of the lumbar vertebrae using MRI images from 53 control patients with pre-existing MRI examinations, 19 prospectively MRI-imaged healthy controls, and 24 patients with Marfan syndrome with prior MRI or CT lumbar spine imaging. Statistical analysis utilized linear and logistic regression, Pearson correlation, and receiver operating characteristic (ROC) curves. Results: AP-DSD and TR-DSD measurements were reproducible between two readers (r = 0.91 and 0.87, respectively). DSD (L1–L5) was not different between male and female controls in the AP or TR plane (p = 0.43; p = 0.40, respectively), and did not vary by age (p = 0.62; p = 0.25) or height (p = 0.64; p = 0.32). AP-VBD was greater in males versus females (p = 1.5 × 10 −8 ), resulting in a smaller dural sac ratio (DSR) (DSD/VBD) in males (p = 5.8 × 10 −6 ). Marfan patients had larger AP-DSDs and TR-DSDs than controls (p = 5.9 × 10 −9 ; p = 6.5 × 10 −9 , respectively). Compared to DSR, AP-DSD and TR-DSD better discriminate Marfan from control subjects based on area under the curve (AUC) values from unadjusted ROCs (AP-DSD p < 0.01; TR-DSD p = 0.04). Conclusion: Individual vertebrae and L1–L5 (average) AP-DSD and TR-DSD measurements are simple, reliable, and reproducible for quantitating dural sac size without needing to control for gender, age, or height. - Highlights: • DSD (L1-L5) does not differ in the AP or TR plane by gender, height, or age. • AP- and TR-DSD measures correlate well between readers with different experience. • Height is positively correlated to AP-VBD in both males and females. • Varying

A new fluorescence-based method identifies protein phosphatases regulating lipid droplet metabolism.

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Bruno L Bozaquel-Morais

Full Text Available In virtually every cell, neutral lipids are stored in cytoplasmic structures called lipid droplets (LDs and also referred to as lipid bodies or lipid particles. We developed a rapid high-throughput assay based on the recovery of quenched BODIPY-fluorescence that allows to quantify lipid droplets. The method was validated by monitoring lipid droplet turnover during growth of a yeast culture and by screening a group of strains deleted in genes known to be involved in lipid metabolism. In both tests, the fluorimetric assay showed high sensitivity and good agreement with previously reported data using microscopy. We used this method for high-throughput identification of protein phosphatases involved in lipid droplet metabolism. From 65 yeast knockout strains encoding protein phosphatases and its regulatory subunits, 13 strains revealed to have abnormal levels of lipid droplets, 10 of them having high lipid droplet content. Strains deleted for type I protein phosphatases and related regulators (ppz2, gac1, bni4, type 2A phosphatase and its related regulator (pph21 and sap185, type 2C protein phosphatases (ptc1, ptc4, ptc7 and dual phosphatases (pps1, msg5 were catalogued as high-lipid droplet content strains. Only reg1, a targeting subunit of the type 1 phosphatase Glc7p, and members of the nutrient-sensitive TOR pathway (sit4 and the regulatory subunit sap190 were catalogued as low-lipid droplet content strains, which were studied further. We show that Snf1, the homologue of the mammalian AMP-activated kinase, is constitutively phosphorylated (hyperactive in sit4 and sap190 strains leading to a reduction of acetyl-CoA carboxylase activity. In conclusion, our fast and highly sensitive method permitted us to catalogue protein phosphatases involved in the regulation of LD metabolism and present evidence indicating that the TOR pathway and the SNF1/AMPK pathway are connected through the Sit4p-Sap190p pair in the control of lipid droplet biogenesis.

Conjunctival sac bacterial flora isolated prior to cataract surgery

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Suto C

2012-01-01

Full Text Available Chikako Suto1,2, Masahiro Morinaga1,2, Tomoko Yagi1,2, Chieko Tsuji3, Hiroshi Toshida41Department of Ophthalmology, Saiseikai Kurihashi Hospital, Saitama; 2Department of Ophthalmology, Tokyo Women's Medical University, Tokyo; 3Department of Clinical Laboratory, Saiseikai Kurihashi Hospital, Saitama; 4Department of Ophthalmology, Juntendo University Shizuoka Hospital, Izunokuni, Shizuoka, JapanObjective: To determine the trends of conjunctival sac bacterial flora isolated from patients prior to cataract surgery.Subjects and methods: The study comprised 579 patients (579 eyes who underwent cataract surgery. Specimens were collected by lightly rubbing the inferior palpebral conjunctival sac with a sterile cotton swab 2 weeks before surgery, and then cultured for isolation of bacteria and antimicrobial sensitivity testing. The bacterial isolates and percentage of drug-resistant isolates were compared among age groups and according to whether or not patients had diabetes mellitus, hyperlipidemia, dialysis therapy, oral steroid use, dry eye syndrome, or allergic conjunctivitis.Results: The bacterial isolation rate was 39.2%. There were 191 strains of Gram-positive cocci, accounting for the majority of all isolates (67.0%, among which methicillin-sensitive coagulase-negative staphylococci was the most frequent (127 strains, 44.5%, followed by methicillin-resistant coagulase-negative staphylococci (37 strains, 12.7%. All 76 Gram-positive bacillary isolates (26.7% were from the genus Corynebacterium. Among the 16 Gram-negative bacillary isolates (5.9%, the most frequent was Escherichia coli (1.0%. The bacterial isolation rate was higher in patients >60 years old, and was lower in patients with dry eye syndrome, patients under topical treatment for other ocular disorders, and patients with hyperlipidemia. There was no significant difference in bacterial isolation rate with respect to the presence/absence of diabetes mellitus, steroid therapy, dialysis, or

Phosphatase activity of Poa pratensis seeds. II. Purification and characterization of acid phosphatase Ia2 and Ia3

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I. Lorenc-Kubis

2015-01-01

Full Text Available Two acid phosphatases (Ia2, Ia3 have been isolated from Poa pratensis seeds and partially purified. Both enzymes showed maximal activity at pH 4,9. They exhibited high activity towards p-nitrophenyl phosphate, inorganic pyrophosphate and phenyl phosphate, much less activity towards glucose-6 phosphate, and mononucleotides. Phosphatases a2 and a3 differed in their activity towards ADP. Orthophosphate, fluoride and Zn2+ were effective inhibitors. EDTA, β-mercaptoethanol and Mg2+ activated phophatase a2 but had no effect on phosphatase a3. Zn2+ inhibited the activity of phosphatase a2 noncompetitively, whereas phosphatase a3 showed inhibition of mixed type. Trypsin, chymotrypsin and pronase had no effect on the enzyme activities of both molecular forms.

Entire lacrimal sac within the ethmoid sinus: outcomes of powered endoscopic dacryocystorhinostomy

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Ali MJ

2016-07-01

Full Text Available Mohammad Javed Ali, Swati Singh, Milind N NaikInstitute of Dacryology, LV Prasad Eye Institute, Hyderabad, India Background: The aim of this study was to report the outcomes of powered endoscopic dacryocystorhinostomy (PEnDCR in patients with lacrimal sac within the sinus.Materials and methods: Retrospective analysis was performed on all patients who underwent PEnDCR and were intraoperatively documented to have complete lacrimal sac in sinus. Data collected included demographics, clinical presentations, associated lacrimal and nasal anomalies, intraoperative findings, intraoperative guidance, complications, postoperative ostium behavior, and anatomical and functional success. A minimum follow-up of 6 months postsurgery was considered for final analysis.Results: A total of 17 eyes of 15 patients underwent PEnDCR using standard protocols, but with additional intraoperative guidance where required and careful maneuvering in the ethmoid sinus. The mean age of the patients was 37.2 (range 17–60 years. Of the unilateral cases, 69% (nine of 13 showed left-side predisposition; 80% of patients showed regurgitation on pressure over the lacrimal sac area. Associated lacrimal and nasal anomalies were observed in 13.3% (two of 15 and 40% (six of 15, respectively. At a mean follow-up of 6.6 months, anatomical and functional success were observed in 93.3% (14 of 15. One patient showed failure secondary to cicatricial closure of the ostium.Conclusion: An entire sac within an ethmoid sinus poses a surgical challenge. Good sinus-surgery training, thorough knowledge of endoscopic anatomy, careful maneuvering, and use of intraoperative navigation guidance result in good outcomes with PEnDCR.Keywords: lacrimal sac, ethmoid sinus, endoscopic, DCR

Plant-derived SAC domain of PAR-4 (Prostate Apoptosis Response 4 exhibits growth inhibitory effects in prostate cancer cells

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Shayan eSarkar

2015-10-01

Full Text Available The gene Par-4 (Prostate Apoptosis Response 4 was originally identified in prostate cancer cells undergoing apoptosis and its product Par-4 showed cancer specific pro-apoptotic activity. Particularly, the SAC domain of Par-4 (SAC-Par-4 selectively kills cancer cells leaving normal cells unaffected. The therapeutic significance of bioactive SAC-Par-4 is enormous in cancer biology; however, its large scale production is still a matter of concern. Here we report the production of SAC-Par-4-GFP fusion protein coupled to translational enhancer sequence (5′ AMV and apoplast signal peptide (aTP in transgenic Nicotiana tabacum cv. Samsun NN plants under the control of a unique recombinant promoter M24. Transgene integration was confirmed by genomic DNA PCR, Southern and Northern blotting, Real-time PCR and Nuclear run-on assays. Results of Western blot analysis and ELISA confirmed expression of recombinant SAC-Par-4-GFP protein and it was as high as 0.15% of total soluble protein. In addition, we found that targeting of plant recombinant SAC-Par-4-GFP to the apoplast and endoplasmic reticulum (ER was essential for the stability of plant recombinant protein in comparison to the bacterial derived SAC-Par-4. Deglycosylation analysis demonstrated that ER-targeted SAC-Par-4-GFP-SEKDEL undergoes O-linked glycosylation unlike apoplast-targeted SAC-Par-4-GFP. Furthermore, various in vitro studies like mammalian cells proliferation assay (MTT, apoptosis induction assays, and NF-κB suppression suggested the cytotoxic and apoptotic properties of plant-derived SAC-Par-4-GFP against multiple prostate cancer cell lines. Additionally, pre-treatment of MAT-LyLu prostate cancer cells with purified SAC-Par-4-GFP significantly delayed the onset of tumor in a syngeneic rat prostate cancer model. Taken altogether, we proclaim that plant made SAC-Par-4 may become a useful alternate therapy for effectively alleviating cancer in the new era.

Determination of the inferior border of the thecal sac using magnetic resonance imaging: implications on radiation therapy treatment planning

International Nuclear Information System (INIS)

Scharf, Carole B.; Paulino, Arnold C.; Goldberg, Kenneth N.

1998-01-01

Purpose: To determine whether the traditional teaching of placing the caudal border of the spinal field at the S2-S3 interspace in children receiving craniospinal irradiation (CSI) is appropriate. Methods and Materials: Twenty-three children had magnetic resonance imaging (MRI) of the spine with gadolinium prior to craniospinal irradiation at one institution. Thecal sac termination using MRI was determined by drawing a perpendicular line from the point of convergence of dural margins to the corresponding vertebral body. Results: Location of thecal sac termination varied from mid-S1 to low S3 vertebral body, with the most frequent site at the upper S2 vertebral level. Only 2 of 23 (8.7%) children had thecal sac terminations below the S2-S3 interspace. For the nine patients with neuraxis disease, none had thecal sac terminations below the S2-S3 interspace. In seven of the nine patients who had neuraxis seeding at initial presentation, MRI of the spine after CSI was performed and showed that thecal sac termination was lower after radiation therapy in two children, higher in one, and the same in four. Conclusions: In 2 of 23 children (8.7%), placement of the inferior border at the bottom of the S2 vertebral body would have missed the entire thecal sac. Treatment to the entire neuraxis with adequate coverage of distal spinal theca can be achieved by using MRI. Individualized spinal fields using the MRI may help minimize radiation scatter to the gonads while adequately covering the target volume

Structural basis for different phosphoinositide specificities of the PX domains of sorting nexins regulating G-protein signaling.

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Mas, Caroline; Norwood, Suzanne J; Bugarcic, Andrea; Kinna, Genevieve; Leneva, Natalya; Kovtun, Oleksiy; Ghai, Rajesh; Ona Yanez, Lorena E; Davis, Jasmine L; Teasdale, Rohan D; Collins, Brett M

2014-10-10

Sorting nexins (SNXs) or phox homology (PX) domain containing proteins are central regulators of cell trafficking and signaling. A subfamily of PX domain proteins possesses two unique PX-associated domains, as well as a regulator of G protein-coupled receptor signaling (RGS) domain that attenuates Gαs-coupled G protein-coupled receptor signaling. Here we delineate the structural organization of these RGS-PX proteins, revealing a protein family with a modular architecture that is conserved in all eukaryotes. The one exception to this is mammalian SNX19, which lacks the typical RGS structure but preserves all other domains. The PX domain is a sensor of membrane phosphoinositide lipids and we find that specific sequence alterations in the PX domains of the mammalian RGS-PX proteins, SNX13, SNX14, SNX19, and SNX25, confer differential phosphoinositide binding preferences. Although SNX13 and SNX19 PX domains bind the early endosomal lipid phosphatidylinositol 3-phosphate, SNX14 shows no membrane binding at all. Crystal structures of the SNX19 and SNX14 PX domains reveal key differences, with alterations in SNX14 leading to closure of the binding pocket to prevent phosphoinositide association. Our findings suggest a role for alternative membrane interactions in spatial control of RGS-PX proteins in cell signaling and trafficking. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Ion channel regulation by phosphoinositides analyzed with VSPs – PI(4,5P2 affinity, phosphoinositide selectivity, and PI(4,5P2 pool accessibility

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Alexandra eRjasanow

2015-06-01

Full Text Available The activity of many proteins depends on the phosphoinositide (PI content of the membrane. E.g., dynamic changes of the concentration of PI(4,5P2 are cellular signals that regulate ion channels. The susceptibility of a channel to such dynamics depends on its affinity for PI(4,5P2. Yet, measuring affinities for endogenous PIs has not been possible directly, but has relied largely on the response to soluble analogs, which may not quantitatively reflect binding to native lipids.Voltage-sensitive phosphatases (VSPs turn over PI(4,5P2 to PI(4P when activated by depolarization. In combination with voltage-clamp electrophysiology VSPs are useful tools for rapid and reversible depletion of PI(4,5P2. Because cellular PI(4,5P2 is resynthesized rapidly, steady state PI(4,5P2 changes with the degree of VSP activation and thus depends on membrane potential.Here we show that titration of endogenous PI(4,5P2 with Ci-VSP allows for the quantification of relative PI(4,5P2 affinities of ion channels. The sensitivity of inward rectifier and voltage-gated K+ channels to Ci-VSP allowed for comparison of PI(4,5P2 affinities within and across channel subfamilies and detected changes of affinity in mutant channels. The results also reveal that VSPs are useful only for PI effectors with high binding specificity among PI isoforms, because PI(4,5P2 depletion occurs at constant overall PI level. Thus, Kir6.2, a channel activated by PI(4,5P2 and PI(4P was insensitive to VSP.Surprisingly, despite comparable PI(4,5P2 affinity as determined by Ci-VSP, the Kv7 and Kir channel families strongly differed in their sensitivity to receptor-mediated depletion of PI(4,5P2. While Kv7 members were highly sensitive to activation of PLC by Gq-coupled receptors, Kir channels were insensitive even when PI(4,5P2 affinity was lowered by mutation. We hypothesize that different channels may be associated with distinct pools of PI(4,5P2 that differ in their accessibility to PLC and VSPs.

Immunohistochemical demonstration of a hitherto undescribed localization of hemoglobin A and F in endodermal cells of normal human yolk sac and endodermal sinus tumor

DEFF Research Database (Denmark)

Albrechtsen, R; Wewer, U; Wimberley, P D

1980-01-01

In this study of 4 human yolk sacs, the presence of hemoglobin A and F (HbA and HbF) is demonstrated for the first time in epithelial cells (type 1) and erythroid-like cells (type 2) in the endodermal layer by immunoperoxidase technique. Our findings strongly support the hypothesis previously...... proposed that the red blood cells formed in the yolk sac are of endodermal origin. Tumor with yolk sac differentiation (8 endodermal sinus tumors and 1 embryonal carcinoma with vitelline areas) similarly showed HbA and HbF localisation in endodermal cells. None of 59 germ cell tumors of other types...

Effect of Multiple Reflow Cycles and Al2O3 Nanoparticles Reinforcement on Performance of SAC305 Lead-Free Solder Alloy

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Tikale, Sanjay; Prabhu, K. Narayan

2018-05-01

The effect of Al2O3 nanoparticles reinforcement on melting behavior, microstructure evolution at the interface and joint shear strength of 96.5Sn3Ag0.5Cu (SAC305) lead-free solder alloy subjected to multiple reflow cycles was investigated. The reinforced SAC305 solder alloy compositions were prepared by adding Al2O3 nanoparticles in different weight fractions (0.05, 0.1, 0.3 and 0.5 wt.%) through mechanical dispersion. Cu/solder/Cu micro-lap-shear solder joint specimens were used to assess the shear strength of the solder joint. Differential scanning calorimetry was used to investigate the melting behavior of SAC305 solder nanocomposites. The solder joint interfacial microstructure was studied using scanning electron microscopy. The results showed that the increase in melting temperature (T L) and melting temperature range of the SAC305 solder alloy by addition of Al2O3 nanoparticles were not significant. In comparison with unreinforced SAC305 solder alloy, the reinforcement of 0.05-0.5 wt.% of Al2O3 nanoparticles improved the solder wettability. The addition of nanoparticles in minor quantity effectively suppressed the Cu6Sn5 IMC growth, improved the solder joint shear strength and ductility under multiple reflow cycles. However, the improvement in solder properties was less pronounced on increasing the nanoparticle content above 0.1 wt.% of the solder alloy.

Yolk sac tumor in a patient with transverse testicular ectopia

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Zhu Yi-Ping

2011-08-01

Full Text Available Abstract Transverse testicular ectopia (TTE is a rare anomaly in which both testes descend through a single inguinal canal. We report a case of yolk sac tumor in the ectopic testis of a patient with TTE. A 24-year-old man presented to our hospital with a left inguinal-mass, right cryptorchidism and elevated alpha-fetoprotein (AFP. A left herniotomy 3 years earlier demonstrated both testes in the left scrotum, one above another positionally. Four months ago, a left scrotal mass appeared and radical orchiectomy of both testes revealed testicular yolk sac tumor of the ectopic testis. An enlarging left inguinal-mass appeared 2 months ago and he was referred to our hospital. Laboratory data showed an elevation of AFP (245.5 ng/ml and a 46 XY karyotype. He underwent bilateral retroperitoneal lymph node dissection and simultaneous left inguinal mass dissection. Histopathologic examination revealed a diagnosis of recurrent yolk sac tumor in the left inguinal mass. The retroperitoneal lymph node was not enlarged and, on histopathology, was not involved. The patient has now been followed up for 8 months without evidence of biochemical or radiological recurrence.

Protein phosphatases decrease their activity during capacitation: a new requirement for this event.

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Janetti R Signorelli

Full Text Available There are few reports on the role of protein phosphatases during capacitation. Here, we report on the role of PP2B, PP1, and PP2A during human sperm capacitation. Motile sperm were resuspended in non-capacitating medium (NCM, Tyrode's medium, albumin- and bicarbonate-free or in reconstituted medium (RCM, NCM plus 2.6% albumin/25 mM bicarbonate. The presence of the phosphatases was evaluated by western blotting and the subcellular localization by indirect immunofluorescence. The function of these phosphatases was analyzed by incubating the sperm with specific inhibitors: okadaic acid, I2, endothall, and deltamethrin. Different aliquots were incubated in the following media: 1 NCM; 2 NCM plus inhibitors; 3 RCM; and 4 RCM plus inhibitors. The percent capacitated sperm and phosphatase activities were evaluated using the chlortetracycline assay and a phosphatase assay kit, respectively. The results confirm the presence of PP2B and PP1 in human sperm. We also report the presence of PP2A, specifically, the catalytic subunit and the regulatory subunits PR65 and B. PP2B and PP2A were present in the tail, neck, and postacrosomal region, and PP1 was present in the postacrosomal region, neck, middle, and principal piece of human sperm. Treatment with phosphatase inhibitors rapidly (≤1 min increased the percent of sperm depicting the pattern B, reaching a maximum of ∼40% that was maintained throughout incubation; after 3 h, the percent of capacitated sperm was similar to that of the control. The enzymatic activity of the phosphatases decreased during capacitation without changes in their expression. The pattern of phosphorylation on threonine residues showed a sharp increase upon treatment with the inhibitors. In conclusion, human sperm express PP1, PP2B, and PP2A, and the activity of these phosphatases decreases during capacitation. This decline in phosphatase activities and the subsequent increase in threonine phosphorylation may be an important

Failure of zinc to prevent dysmorphogenesis of cultured rat conceptuses by anti-yolk sac antiserum

International Nuclear Information System (INIS)

Marlow, R.; Freeman, S.J.

1989-01-01

Day 10 rat conceptuses were cultured for 48h in the presence of either cadmium or anti-vesceral yolk sac antiserum (AVYS). Cadmium was embryotoxic at concentrations exceeding 0.25 ug/ml while AVYS caused embryonic dysmorphogenesis, particularly affecting the optic vesicles, at concentrations of 2 ul/ml and above. The effect of pretreatment with zinc on embryotoxicity caused by cadmium or AVYS was studied. Zinc ameliorated the effects of cadmium but had no effect on AVYS-induced embryonic abnormalities. In a second set of experiments inhibition of 125 I-labelled PVP uptake by the yolk sac of cultured whole conceptuses was studied. Cadmium and AVYS both inhibited uptake compared to control cultures. Zinc again ameliorated the effect of cadmium but had no action against AVYS-induced inhibition. These results are in contrast to their previous findings using isolated cultured yolk sacs in which zinc ameliorated the inhibitory effects on 125 I-labelled PVP uptake of both cadmium and AVYS. These data show that in experiments using the isolated cultured yolk sac and the intact cultured conceptus, a qualitatively different response in yolk sac behavior is observed under similar experimental conditions

An Ancient Protein Phosphatase, SHLP1, Is Critical to Microneme Development in Plasmodium Ookinetes and Parasite Transmission

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Eva-Maria Patzewitz

2013-03-01

Full Text Available Signaling pathways controlled by reversible protein phosphorylation (catalyzed by kinases and phosphatases in the malaria parasite Plasmodium are of great interest, for both increased understanding of parasite biology and identification of novel drug targets. Here, we report a functional analysis in Plasmodium of an ancient bacterial Shewanella-like protein phosphatase (SHLP1 found only in bacteria, fungi, protists, and plants. SHLP1 is abundant in asexual blood stages and expressed at all stages of the parasite life cycle. shlp1 deletion results in a reduction in ookinete (zygote development, microneme formation, and complete ablation of oocyst formation, thereby blocking parasite transmission. This defect is carried by the female gamete and can be rescued by direct injection of mutant ookinetes into the mosquito hemocoel, where oocysts develop. This study emphasizes the varied functions of SHLP1 in Plasmodium ookinete biology and suggests that it could be a novel drug target for blocking parasite transmission.

Estimation of organic carbon deposition into forest ecosystems by determination of the spectral absorption of rainwater in range of ultraviolet radiation (SAC254)

International Nuclear Information System (INIS)

Bartels, U.

1988-01-01

Organic compounds are mostly neglected within deposition measurement programs because their determination is expensive and complicated. A very simple and rapid estimation of total organic carbon (TOC) is possible by determination of the spectral absorption coefficient in the range of ultraviolet radiation at 254 nm wave-length (SAC 254 ): TOC (mg/1) = 0,5 SAC 254 (m −1 ) - 0,15 (author) [de

Cloning and expression of a widely expressed receptor tyrosine phosphatase

DEFF Research Database (Denmark)

Sap, J; D'Eustachio, P; Givol, D

1990-01-01

We describe the identification of a widely expressed receptor-type (transmembrane) protein tyrosine phosphatase (PTPase; EC 3.1.3.48). Screening of a mouse brain cDNA library under low-stringency conditions with a probe encompassing the intracellular (phosphatase) domain of the CD45 lymphocyte...... antigen yielded cDNA clones coding for a 794-amino acid transmembrane protein [hereafter referred to as receptor protein tyrosine phosphatase alpha (R-PTP-alpha)] with an intracellular domain displaying clear homology to the catalytic domains of CD45 and LAR (45% and 53%, respectively). The 142-amino acid...

SHIP-1 Increases Early Oxidative Burst and Regulates Phagosome Maturation in Macrophages1

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Kamen, Lynn A.; Levinsohn, Jonathan; Cadwallader, Amy; Tridandapani, Susheela; Swanson, Joel A.

2010-01-01

Although the inositol phosphatase SHIP-1 is generally thought to inhibit signaling for Fc receptor-mediated phagocytosis, the product of its activity, phosphatidylinositol 3,4 bisphosphate (PI(3,4)P2) has been implicated in activation of the NADPH oxidase. This suggests that SHIP-1 positively regulates generation of reactive oxygen species after phagocytosis. To examine how SHIP-1 activity contributes to Fc receptor-mediated phagocytosis, we measured and compared phospholipid dynamics, membrane trafficking and the oxidative burst in macrophages from SHIP-1-deficient and wild-type mice. SHIP-1-deficient macrophages showed significantly elevated ratios of PI(3,4,5) P3 to PI(3,4)P2 on phagosomal membranes. Imaging reactive oxygen intermediate activities in phagosomes revealed decreased early NADPH oxidase activity in SHIP-1-deficient macrophages. SHIP-1-deficiency also altered later stages of phagosome maturation, as indicated by the persistent elevation of PI(3)P and the early localization of Rab5a to phagosomes. These direct measurements of individual organelles indicate that phagosomal SHIP-1 enhances the early oxidative burst through localized alteration of the membrane 3′ phosphoinositide composition. PMID:18490750

Caged xanthones displaying protein tyrosine phosphatase 1B (PTP1B) inhibition from Cratoxylum cochinchinense.

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Li, Zuo Peng; Lee, Hyeong-Hwan; Uddin, Zia; Song, Yeong Hun; Park, Ki Hun

2018-08-01

Four new caged xanthones (1-4) and two known compounds (5, 6) were isolated from the roots of Cratoxylum cochinchinense, a polyphenol rich plant, collected in China. The structures of the isolated compounds (1-6) were characterized by obtaining their detailed spectroscopic data. In particular, compounds 1 and 6 were fully identified by X-ray crystallographic data. The isolated compounds (1-6) were evaluated against protein tyrosine phosphatase 1B (PTP1B), which plays an important role in diabetes, obesity, and cancer. Among these compounds, 3, 4, and 6 displayed significant inhibition with IC 50 values of 76.3, 43.2, and 6.6 µM, respectively. A detailed kinetic study was conducted by determining K m , V max , and the ratio of K ik and K iv , which revealed that all the compounds behaved as competitive inhibitors. Copyright © 2018 Elsevier Inc. All rights reserved.

Oxygenated fixation demonstrates novel and improved ultrastructural features of the human endolymphatic sac

DEFF Research Database (Denmark)

Møller, Martin Nue; Caye-Thomasen, Per; Qvortrup, Klaus

2013-01-01

OBJECTIVES/HYPOTHESIS: The purpose of the present study is to describe in detail the ultrastructure of the human endolymphatic sac using a new and improved method of fixation as well as a refined surgical approach in obtaining specimens. STUDY DESIGN: Transmission electron microscopy of the human...... epithelial cell lining in all 18 specimens. In general, we found very well-preserved specimens with well-defined intracellular structures. In contrast to the results in former studies, a minimum of fixation artifacts was observed in the present study. Three different cell types were observed...... endolymphatic sac, employing an oxygenated fixative. METHODS: Eighteen tissue samples of the human endolymphatic sac were obtained during surgery for vestibular schwannoma using the translabyrinthine approach. The specimens were fixed in 2% glutaraldehyde in an oxygenated fluorocarbon blood substitute vehicle...

Intrinsic Levanase Activity of Bacillus subtilis 168 Levansucrase (SacB.

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Luz Méndez-Lorenzo

Full Text Available Levansucrase catalyzes the synthesis of fructose polymers through the transfer of fructosyl units from sucrose to a growing fructan chain. Levanase activity of Bacillus subtilis levansucrase has been described since the very first publications dealing with the mechanism of levan synthesis. However, there is a lack of qualitative and quantitative evidence regarding the importance of the intrinsic levan hydrolysis of B. subtilis levansucrase and its role in the levan synthesis process. Particularly, little attention has been paid to the long-term hydrolysis products, including its participation in the final levan molecules distribution. Here, we explored the hydrolytic and transferase activity of the B. subtilis levansucrase (SacB when levans produced by the same enzyme are used as substrate. We found that levan is hydrolyzed through a first order exo-type mechanism, which is limited to a conversion extent of around 30% when all polymer molecules reach a structure no longer suitable to SacB hydrolysis. To characterize the reaction, Isothermal Titration Calorimetry (ITC was employed and the evolution of the hydrolysis products profile followed by HPLC, GPC and HPAEC-PAD. The ITC measurements revealed a second step, taking place at the end of the reaction, most probably resulting from disproportionation of accumulated fructo-oligosaccharides. As levanase, levansucrase may use levan as substrate and, through a fructosyl-enzyme complex, behave as a hydrolytic enzyme or as a transferase, as demonstrated when glucose and fructose are added as acceptors. These reactions result in a wide variety of oligosaccharides that are also suitable acceptors for fructo-oligosaccharide synthesis. Moreover, we demonstrate that SacB in the presence of levan and glucose, through blastose and sucrose synthesis, results in the same fructooligosaccharides profile as that observed in sucrose reactions. We conclude that SacB has an intrinsic levanase activity that

The influence of age on positions of the conus medullaris, Tuffier's line, dural sac, and sacrococcygeal membrane in infants, children, adolescents, and young adults.

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Jung, Ji-Yun; Kim, Eun-Hee; Song, In-Kyung; Lee, Ji-Hyun; Kim, Hee-Soo; Kim, Jin-Tae

2016-12-01

The purpose of this study was to analyze the distances between the conus medullaris and the Tuffier's line, and between the dural sac and the sacrococcygeal membrane (SCM) in the same pediatric population. Spinal magnetic resonance images and simple X-ray images of 350 patients aged from 1 month to 20 years were reviewed. Positions of the conus medullaris, Tuffier's line, the dural sac, and the SCM were identified. Each position was recorded in relation to the corresponding vertebral body segments. The distances between the conus medullaris and Tuffier's line, and between the dural sac and the SCM, were measured and then assessed according to age using an analysis of variance and a linear regression analysis. The median levels of the conus medullaris and Tuffier's line were in the lower third of L1 [the first lumbar vertebral body] and the middle third of L5, respectively. The levels of the conus medullaris and Tuffier's line were lower in younger populations. The distance between the conus medullaris and Tuffier's line ranged from 1.5 to 4.75 vertebral body height. However, a narrow range of 1.5-2.5 vertebral height was observed only in children younger than 2 years. The level of the dural sac did not differ greatly by age, but the upper limit of the SCM was lower in older populations. The distance between the dural sac and the upper limit of the SCM increased with age. In children, there is a distance of 1.5-4.75 vertebral body height between the conus medullaris and the Tuffier's line. However, these distances were narrower among younger populations. The distance between the dural sac and the upper limit of the SCM increased with age. © 2016 John Wiley & Sons Ltd.

Purification and characterization of a phosphotyrosyl-protein phosphatase from wheat seedlings.

Science.gov (United States)

Cheng, H F; Tao, M

1989-10-19

A neutral phosphatase which catalyzes the hydrolysis of p-nitrophenylphosphate has been purified to homogeneity from wheat seedlings. The enzyme is a monomeric glycoprotein exhibiting a molecular weight of 35,000, frictional ratio of 1.22, Stokes' radius of 260 nm, and sedimentation coefficient of 3.2 S. That the enzyme is a glycoprotein is surmised from its chromatographic property on Concanavalin A-Sepharose column. An examination of the substrate specificity indicates that the enzyme exhibits a preference for phosphotyrosine over a number of phosphocompounds, including p-nitrophenylphosphate and several glycolytic intermediates. Both phosphoserine and phosphothreonine are not hydrolyzed by the enzyme. The phosphatase activity is not affected by high concentrations of chelating agents and does not require metal ions. Molybdate, orthovanadate, Zn2+, and Hg2+ are all potent inhibitors of the phosphatase activity. The ability of the phosphatase to dephosphorylate protein phosphotyrosine has been investigated. [32P-Tyr]poly(Glu,Tyr)n, [32P-Tyr]alkylated bovine serum albumin, [32P-Tyr]angiotensin-I, and [32P-Tyr]band 3 (from human erythrocyte) are all substrates of the phosphatase. On the other hand, the enzyme has no activity toward protein phosphoserine and phosphothreonine. Our result further indicates that the neutral phosphatase is distinct from the wheat germ acid phosphatase. The latter enzyme is found to dephosphorylate phosphotyrosyl as well as phosphoseryl and phosphothreonyl groups in proteins. In light of the many similarities in properties to phosphotyrosyl protein phosphatases isolated from several sources, it is suggested that the wheat seedling phosphatase may participate in cellular regulation involving protein tyrosine phosphorylation.

The genetics of feto-placental development: A study of acid phosphatase locus 1 and adenosine deaminase polymorphisms in a consecutive series of newborn infants

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Bergamaschi Antonio

2008-09-01

Full Text Available Abstract Background Acid phosphatase locus 1 and adenosine deaminase locus 1 polymorphisms show cooperative effects on glucose metabolism and immunological functions. The recent observation of cooperation between the two systems on susceptibility to repeated spontaneous miscarriage prompted us to search for possible interactional effects between these genes and the correlation between birth weight and placental weight. Deviation from a balanced development of the feto-placental unit has been found to be associated with perinatal morbidity and mortality and with cardiovascular diseases in adulthood. Methods We examined 400 consecutive newborns from the Caucasian population of Rome. Birth weight, placental weight, and gestational length were registered. Acid phosphatase locus 1 and adenosine deaminase locus 1 phenotypes were determined by starch gel electrophoresis and correlation analysis was performed by SPSS programs. Informed verbal consent to participate in the study was obtained from the mothers. Results Highly significant differences in birth weight-placental weight correlations were observed among acid phosphatase locus 1 phenotypes (p = 0.005. The correlation between birth weight and placental weight was markedly elevated in subjects carrying acid phosphatase locus 1 phenotypes with medium-low F isoform concentration (A, CA and CB phenotypes compared to those carrying acid phosphatase locus 1 phenotypes with medium-high F isoform concentration (BA and B phenotypes (p = 0.002. Environmental and developmental variables were found to exert a significant effect on birth weight-placental weight correlation in subjects with medium-high F isoform concentrations, but only a marginal effect was observed in those with medium-low F isoform concentrations. The correlation between birth weight and placental weight is higher among carriers of the adenosine deaminase locus 1 allele*2, which is associated with low activity, than in homozygous adenosine

A Global Protein Kinase and Phosphatase Interaction Network in Yeast

Science.gov (United States)

Breitkreutz, Ashton; Choi, Hyungwon; Sharom, Jeffrey R.; Boucher, Lorrie; Neduva, Victor; Larsen, Brett; Lin, Zhen-Yuan; Breitkreutz, Bobby-Joe; Stark, Chris; Liu, Guomin; Ahn, Jessica; Dewar-Darch, Danielle; Reguly, Teresa; Tang, Xiaojing; Almeida, Ricardo; Qin, Zhaohui Steve; Pawson, Tony; Gingras, Anne-Claude; Nesvizhskii, Alexey I.; Tyers, Mike

2011-01-01

The interactions of protein kinases and phosphatases with their regulatory subunits and substrates underpin cellular regulation. We identified a kinase and phosphatase interaction (KPI) network of 1844 interactions in budding yeast by mass spectrometric analysis of protein complexes. The KPI network contained many dense local regions of interactions that suggested new functions. Notably, the cell cycle phosphatase Cdc14 associated with multiple kinases that revealed roles for Cdc14 in mitogen-activated protein kinase signaling, the DNA damage response, and metabolism, whereas interactions of the target of rapamycin complex 1 (TORC1) uncovered new effector kinases in nitrogen and carbon metabolism. An extensive backbone of kinase-kinase interactions cross-connects the proteome and may serve to coordinate diverse cellular responses. PMID:20489023

A preliminary X-ray study of d,d-heptose-1,7-bisphosphate phosphatase from Burkholderia thailandensis E264

International Nuclear Information System (INIS)

Kim, Mi-Sun; Shin, Dong Hae

2010-01-01

In this study, d,d-heptose-1,7-bisphosphate phosphatase has been cloned, expressed, purified and crystallized. d,d-Heptose-1,7-bisphosphate phosphatase (GmhB), which is involved in the third step of the NDP-heptose biosynthesis pathway, converts d,d-heptose-1,7-bisphosphate to d,d-heptose-1-phosphate. This biosynthesis pathway is a target for new antibiotics or antibiotic adjuvants for Gram-negative pathogens. Burkholderia thailandensis is a useful surrogate organism for studying the pathogenicity of melioidosis owing to its extensive genomic similarity to B. pseudomallei. Melioidosis caused by B. pseudomallei is a serious invasive disease of animals and humans in tropical and subtropical areas. In this study, GmhB has been cloned, expressed, purified and crystallized. X-ray data have also been collected to 2.50 Å resolution using synchrotron radiation. The crystal belonged to space group P6, with unit-cell parameters a = 243.2, b = 243.2, c = 41.1 Å

The internal vertebral venous plexus prevents compression of the dural sac during atlanto-axial rotation

Energy Technology Data Exchange (ETDEWEB)

Reesink, E.M.; Lataster, L.M.A.; Mameren, H. van [Dept. of Anatomy/Embryology, Maastricht Univ. (Netherlands); Wilmink, J.T. [Dept. of Radiology, University Hospital Maastricht (Netherlands); Kingma, H. [Dept. of ENT, University Hospital Maastricht (Netherlands)

2001-10-01

Deformation of the extradural space and the possibility of impression upon the dural sac during atlanto-axial rotation are investigated. Atlanto-axial rotation leads to a reduction in the cross-sectional area of the bony spinal canal of approximately 40 %. Atlanto-axial rotation was recorded by endocanalar views from a video camera fixed inside the skull of six unembalmed cadavers. Axial thin-section T1-weighted MRI slice sets were acquired from three volunteers (mid-position and maximal left and right rotation of the head and cervical spine). The axial cross-sectional areas of the bony spinal canal, dural sac and spinal cord were measured. In two other persons post-gadolinium contrast-enhanced T1-weighted MRI volume scans with fat-suppression prepulse were acquired (mid-position and rotation) to determine venous contents of the extradural space. The 50:50 ratio between left and right extradural halves in mid-position changed to an ipsilateral:contralateral ratio of 20:80 in maximum rotation at the level just above the lateral C1-C2 joints. Directly below these joints the opposite occurred. The post-contrast studies showed an enhancing internal vertebral venous plexus (IVVP), which almost completely occupied the extradural space at the atlanto-axial level. This could not be shown in the cadaver experiments, because of absence of blood and cerebrospinal fluid (CSF) pressure. During atlanto-axial rotation blood displacement in the IVVP allows major deformations of the extradural space. This prevents dural sac impression. (orig.)

Influence of triethyl phosphate on phosphatase activity in shooting range soil: Isolation of a zinc-resistant bacterium with an acid phosphatase.

Science.gov (United States)

Story, Sandra; Brigmon, Robin L

2017-03-01

Phosphatase-mediated hydrolysis of organic phosphate may be a viable means of stabilizing heavy metals via precipitation as a metal phosphate in bioremediation applications. We investigated the effect of triethyl phosphate (TEP) on soil microbial-phosphatase activity in a heavy-metal contaminated soil. Gaseous TEP has been used at subsurface sites for bioremediation of organic contaminants but not applied in heavy-metal contaminated areas. Little is known about how TEP affects microbial activity in soils and it is postulated that TEP can serve as a phosphate source in nutrient-poor groundwater and soil/sediments. Over a 3-week period, TEP amendment to microcosms containing heavy-metal contaminated soil resulted in increased activity of soil acid-phosphatase and repression of alkaline phosphatase, indicating a stimulatory effect on the microbial population. A soil-free enrichment of microorganisms adapted to heavy-metal and acidic conditions was derived from the TEP-amended soil microcosms using TEP as the sole phosphate source and the selected microbial consortium maintained a high acid-phosphatase activity with repression of alkaline phosphatase. Addition of 5mM zinc to soil-free microcosms had little effect on acid phosphatase but inhibited alkaline phosphatase. One bacterial member from the consortium, identified as Burkholderia cepacia sp., expressed an acid-phosphatase activity uninhibited by high concentrations of zinc and produced a soluble, indigo pigment under phosphate limitation. The pigment was produced in a phosphate-free medium and was not produced in the presence of TEP or phosphate ion, indicative of purple acid-phosphatase types that are pressed by bioavailable phosphate. These results demonstrate that TEP amendment was bioavailable and increased overall phosphatase activity in both soil and soil-free microcosms supporting the possibility of positive outcomes in bioremediation applications. Copyright © 2016. Published by Elsevier Inc.

Development of the inverted visceral yolk sac in three species of caviids (Rodentia, Caviomorpha, Caviidae).

Science.gov (United States)

Miglino, M A; Franciolli, A L R; de Oliveira, M F; Ambrósio, C E; Bonatelli, M; Machado, M R F; Mess, A

2008-08-01

Guinea pig related rodents possess numerous derived placental characters. We attempt to identify diversity within the visceral yolk sac and its association with the chorioallantoic placenta in three species of caviids, two of them possessing a capsule formed by the decidua that covers the chorioallantoic placenta. The results verify that in early pregnancy all three species have an inverted yolk sac placenta. In advanced pregnancy the species differ: Galea spixii, as representative without a capsule, bear a yolk sac in apposition to the chorioallantoic placenta with signs of exchange activity until term. Galea is similar to other caviomorphs in this respect. In Dasyprocta leporina and Cuniculus paca, the representatives possessing a capsule, the yolk sac endoderm lacks signs of substance exchange. Evidently, the presence of a capsule prevents such an interaction. The variations established here must be considered if animal models for human placentation are required which have restricted access to the chorioallantoic placenta from the outside.

Novel Glucose-1-Phosphatase with High Phytase Activity and Unusual Metal Ion Activation from Soil Bacterium Pantoea sp. Strain 3.5.1.

Science.gov (United States)

Suleimanova, Aliya D; Beinhauer, Astrid; Valeeva, Liia R; Chastukhina, Inna B; Balaban, Nelly P; Shakirov, Eugene V; Greiner, Ralf; Sharipova, Margarita R

2015-10-01

Phosphorus is an important macronutrient, but its availability in soil is limited. Many soil microorganisms improve the bioavailability of phosphate by releasing it from various organic compounds, including phytate. To investigate the diversity of phytate-hydrolyzing bacteria in soil, we sampled soils of various ecological habitats, including forest, private homesteads, large agricultural complexes, and urban landscapes. Bacterial isolate Pantoea sp. strain 3.5.1 with the highest level of phytase activity was isolated from forest soil and investigated further. The Pantoea sp. 3.5.1 agpP gene encoding a novel glucose-1-phosphatase with high phytase activity was identified, and the corresponding protein was purified to apparent homogeneity, sequenced by mass spectroscopy, and biochemically characterized. The AgpP enzyme exhibits maximum activity and stability at pH 4.5 and at 37°C. The enzyme belongs to a group of histidine acid phosphatases and has the lowest Km values toward phytate, glucose-6-phosphate, and glucose-1-phosphate. Unexpectedly, stimulation of enzymatic activity by several divalent metal ions was observed for the AgpP enzyme. High-performance liquid chromatography (HPLC) and high-performance ion chromatography (HPIC) analyses of phytate hydrolysis products identify dl-myo-inositol 1,2,4,5,6-pentakisphosphate as the final product of the reaction, indicating that the Pantoea sp. AgpP glucose-1-phosphatase can be classified as a 3-phytase. The identification of the Pantoea sp. AgpP phytase and its unusual regulation by metal ions highlight the remarkable diversity of phosphorus metabolism regulation in soil bacteria. Furthermore, our data indicate that natural forest soils harbor rich reservoirs of novel phytate-hydrolyzing enzymes with unique biochemical features. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Arabidopsis protein phosphatase DBP1 nucleates a protein network with a role in regulating plant defense.

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José Luis Carrasco

Full Text Available Arabidopsis thaliana DBP1 belongs to the plant-specific family of DNA-binding protein phosphatases. Although recently identified as a novel host factor mediating susceptibility to potyvirus, little is known about DBP1 targets and partners and the molecular mechanisms underlying its function. Analyzing changes in the phosphoproteome of a loss-of-function dbp1 mutant enabled the identification of 14-3-3λ isoform (GRF6, a previously reported DBP1 interactor, and MAP kinase (MAPK MPK11 as components of a small protein network nucleated by DBP1, in which GRF6 stability is modulated by MPK11 through phosphorylation, while DBP1 in turn negatively regulates MPK11 activity. Interestingly, grf6 and mpk11 loss-of-function mutants showed altered response to infection by the potyvirus Plum pox virus (PPV, and the described molecular mechanism controlling GRF6 stability was recapitulated upon PPV infection. These results not only contribute to a better knowledge of the biology of DBP factors, but also of MAPK signalling in plants, with the identification of GRF6 as a likely MPK11 substrate and of DBP1 as a protein phosphatase regulating MPK11 activity, and unveils the implication of this protein module in the response to PPV infection in Arabidopsis.

Penguin lungs and air sacs: implications for baroprotection, oxygen stores and buoyancy.

Science.gov (United States)

Ponganis, P J; St Leger, J; Scadeng, M

2015-03-01

The anatomy and volume of the penguin respiratory system contribute significantly to pulmonary baroprotection, the body O2 store, buoyancy and hence the overall diving physiology of penguins. Therefore, three-dimensional reconstructions from computerized tomographic (CT) scans of live penguins were utilized to measure lung volumes, air sac volumes, tracheobronchial volumes and total body volumes at different inflation pressures in three species with different dive capacities [Adélie (Pygoscelis adeliae), king (Aptenodytes patagonicus) and emperor (A. forsteri) penguins]. Lung volumes scaled to body mass according to published avian allometrics. Air sac volumes at 30 cm H2O (2.94 kPa) inflation pressure, the assumed maximum volume possible prior to deep dives, were two to three times allometric air sac predictions and also two to three times previously determined end-of-dive total air volumes. Although it is unknown whether penguins inhale to such high volumes prior to dives, these values were supported by (a) body density/buoyancy calculations, (b) prior air volume measurements in free-diving ducks and (c) previous suggestions that penguins may exhale air prior to the final portions of deep dives. Based upon air capillary volumes, parabronchial volumes and tracheobronchial volumes estimated from the measured lung/airway volumes and the only available morphometry study of a penguin lung, the presumed maximum air sac volumes resulted in air sac volume to air capillary/parabronchial/tracheobronchial volume ratios that were not large enough to prevent barotrauma to the non-collapsing, rigid air capillaries during the deepest dives of all three species, and during many routine dives of king and emperor penguins. We conclude that volume reduction of airways and lung air spaces, via compression, constriction or blood engorgement, must occur to provide pulmonary baroprotection at depth. It is also possible that relative air capillary and parabronchial volumes are

Loss of SHP-1 tyrosine phosphatase expression correlates with the advanced stages of cutaneous T-cell lymphoma

DEFF Research Database (Denmark)

Witkiewicz, Agnieszka; Raghunath, Puthiyaveettil; Wasik, Agnieszka

2007-01-01

Cutaneous T-cell lymphoma (CTCL) comprises distinct and often progressive stages of skin involvement by patches, plaques, and tumors. We have previously demonstrated that CTCL-derived malignant T-cell lines display loss of a tumor suppressor SHP-1 tyrosine phosphatase because of epigenetic...

Compiling the functional data-parallel language SaC for Microgrids of Self-Adaptive Virtual Processors

NARCIS (Netherlands)

Grelck, C.; Herhut, S.; Jesshope, C.; Joslin, C.; Lankamp, M.; Scholz, S.-B.; Shafarenko, A.

2009-01-01

We present preliminary results from compiling the high-level, functional and data-parallel programming language SaC into a novel multi-core design: Microgrids of Self-Adaptive Virtual Processors (SVPs). The side-effect free nature of SaC in conjunction with its data-parallel foundation make it an

Excavations at Kainapirina (SAC), Watom Island, Papua New Guinea

International Nuclear Information System (INIS)

Green, R.C.; Anson, D.

1998-01-01

This paper is the final report on excavations in 1985 at the locality of Kainapirina (site SAC), situated on the Reber mission station adjacent to Rakival village on Watom Island. It backgrounds previous investigations there, the objectives of the 1985 endeavours, and the excavation strategies undertaken to achieve them. The occupation sequence based on stratigraphy, dating, and associated structural features is described and illustrated. Aspects of the human skeletal remains recovered are briefly reviewed; the economic evidence is discussed in detail. Analyses are provided of the various portable artefacts from these Lapita contexts, particularly stone adzes. obsidian, and pottery. These document an 'exotic to Watom' exchange component among the local manufactures. It is concluded that these 1985 excavations at SAC currently best enable an understanding of the significance of the entire Reber-Rakival Lapita site. (author)

Primary Yolk Sac Tumor of the Omentum: Case Report

Energy Technology Data Exchange (ETDEWEB)

Baek, Chang Kyu; Oh, Young Taik; Jung, Dae Chul [Dept. of Radiology, Research Institue of Radiological Science, Yensei University College of Medicine, Seoul (Korea, Republic of); Bae, Yoon Sung [Dept. of Pathology, Yensei University College of Medicine, Seoul (Korea, Republic of)

2012-01-15

A 32-year-old woman had been referred to our hospital for lower abdominal pain. Pelvic ultrasonography and magnetic resonance imaging revealed a huge solid mass with an internal cystic portion. The patient underwent a staging laparotomy and subsequent total abdominal hysterectomy with bilateral salpingo-oophorectomy, bilateral pelvic lymph nodes sampling, and total omentectomy. At staging laparotomy, a large omental mass was found. The tumor displayed the typical histological patterns observed in the yolk sac tumor. The alpha-fetoprotein (AFP) serum value on the 10th day after surgery was 11,576.67 IU/mL and decreased to 6.46 IU/mL after chemotherapy. At the end of the treatment, all the findings, including the AFP level, were normal. We report a case of primary yolk sac tumor of the omentum in a 32-year-old woman.

Primary Yolk Sac Tumor of the Omentum: Case Report

International Nuclear Information System (INIS)

Baek, Chang Kyu; Oh, Young Taik; Jung, Dae Chul; Bae, Yoon Sung

2012-01-01

A 32-year-old woman had been referred to our hospital for lower abdominal pain. Pelvic ultrasonography and magnetic resonance imaging revealed a huge solid mass with an internal cystic portion. The patient underwent a staging laparotomy and subsequent total abdominal hysterectomy with bilateral salpingo-oophorectomy, bilateral pelvic lymph nodes sampling, and total omentectomy. At staging laparotomy, a large omental mass was found. The tumor displayed the typical histological patterns observed in the yolk sac tumor. The alpha-fetoprotein (AFP) serum value on the 10th day after surgery was 11,576.67 IU/mL and decreased to 6.46 IU/mL after chemotherapy. At the end of the treatment, all the findings, including the AFP level, were normal. We report a case of primary yolk sac tumor of the omentum in a 32-year-old woman.

Implication of protein tyrosine phosphatase 1B in MCF-7 cell proliferation and resistance to 4-OH tamoxifen

International Nuclear Information System (INIS)

Blanquart, Christophe; Karouri, Salah-Eddine; Issad, Tarik

2009-01-01

The protein tyrosine phosphatase 1B (PTP1B) and the T-cell protein tyrosine phosphatase (TC-PTP) were initially thought to be mainly anti-oncogenic. However, overexpression of PTP1B and TC-PTP has been observed in human tumors, and recent studies have demonstrated that PTP1B contributes to the appearance of breast tumors by modulating ERK pathway. In the present work, we observed that decreasing the expression of TC-PTP or PTP1B in MCF-7 cells using siRNA reduced cell proliferation without affecting cell death. This reduction in proliferation was associated with decreased ERK phosphorylation. Moreover, selection of tamoxifen-resistant MCF-7 cells, by long-term culture in presence of 4-OH tamoxifen, resulted in cells that display overexpression of PTP1B and TC-PTP, and concomitant increase in ERK and STAT3 phosphorylation. siRNA experiments showed that PTP1B, but not TC-PTP, is necessary for resistance to 4-OH tamoxifen. Therefore, our work indicates that PTP1B could be a relevant therapeutic target for treatment of tamoxifen-resistant breast cancers.

Acid phosphatase turnover during repressed and derepressed cultivation of Aspergillus niger

International Nuclear Information System (INIS)

Komano, Teruya

1975-01-01

Enhancement of the activity of acid phosphatase (EC 3.1.3.2) by phosphate starvation in growing Aspergillus niger mycelia was prevented by cycloheximide. This indicates that the enhancement was due to de novo protein synthesis caused by derepression. Radioactive acid phosphatase extracted from mycelia labeled with 14 C-amino acid was separated into at least four fractions. Experiments on pulse labeling and the chasing of the four acid phosphatases revealed the synthesis and degradation of each fraction occurred at different rates; showing a different rate of turnover of the enzyme molecules. The results of similar experiments performed during culture in the presence of phosphate (partially repressed condition) suggested that the marked change in the activity ratios of the four acid phosphatases during cultivation was the result of the active turnover of enzyme molecules. In contrast, the slight changes in the ratios observed during derepressed cultivation seemed to be the result of similar of synthesis and degradation of each phosphatase fraction. (auth.)

Ventilation patterns of the songbird lung/air sac system during different behaviors.

Science.gov (United States)

Mackelprang, Rebecca; Goller, Franz

2013-10-01

Unidirectional, continuous airflow through the avian lung is achieved through an elaborate air sac system with a sequential, posterior to anterior ventilation pattern. This classical model was established through various approaches spanning passively ventilated systems to mass spectrometry analysis of tracer gas flow into various air sacs during spontaneous breathing in restrained ducks. Information on flow patterns in other bird taxa is missing, and these techniques do not permit direct tests of whether the basic flow pattern can change during different behaviors. Here we use thermistors implanted into various locations of the respiratory system to detect small pulses of tracer gas (helium) to reconstruct airflow patterns in quietly breathing and behaving (calling, wing flapping) songbirds (zebra finch and yellow-headed blackbird). The results illustrate that the basic pattern of airflow in these two species is largely consistent with the model. However, two notable differences emerged. First, some tracer gas arrived in the anterior set of air sacs during the inspiration during which it was inhaled, suggesting a more rapid throughput through the lung than previously assumed. Second, differences in ventilation between the two anterior air sacs emerged during calling and wing flapping, indicating that adjustments in the flow pattern occur during dynamic behaviors. It is unclear whether this modulation in ventilation pattern is passive or active. This technique for studying ventilation patterns during dynamic behaviors proves useful for establishing detailed timing of airflow and modulation of ventilation in the avian respiratory system.

Characterization and site-directed mutagenesis of Wzb, an O-phosphatase from Lactobacillus rhamnosus

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Gilbert Christophe

2008-04-01

Full Text Available Abstract Background Reversible phosphorylation events within a polymerisation complex have been proposed to modulate capsular polysaccharide synthesis in Streptococcus pneumoniae. Similar phosphatase and kinase genes are present in the exopolysaccharide (EPS biosynthesis loci of numerous lactic acid bacteria genomes. Results The protein sequence deduced from the wzb gene in Lactobacillus rhamnosus ATCC 9595 reveals four motifs of the polymerase and histidinol phosphatase (PHP superfamily of prokaryotic O-phosphatases. Native and modified His-tag fusion Wzb proteins were purified from Escherichia coli cultures. Extracts showed phosphatase activity towards tyrosine-containing peptides. The purified fusion protein Wzb was active on p-nitrophenyl-phosphate (pNPP, with an optimal activity in presence of bovine serum albumin (BSA 1% at pH 7.3 and a temperature of 75°C. At 50°C, residual activity decreased to 10 %. Copper ions were essential for phosphatase activity, which was significantly increased by addition of cobalt. Mutated fusion Wzb proteins exhibited reduced phosphatase activity on p-nitrophenyl-phosphate. However, one variant (C6S showed close to 20% increase in phosphatase activity. Conclusion These characteristics reveal significant differences with the manganese-dependent CpsB protein tyrosine phosphatase described for Streptococcus pneumoniae as well as with the polysaccharide-related phosphatases of Gram negative bacteria.

Serum alkaline phosphatase screening for vitamin D deficiency states

International Nuclear Information System (INIS)

Shaheen, S.; Barrakzai, Q.

2012-01-01

Objective: To determine whether serum vitamin D levels are correlated with serum levels of alkaline phosphatase or not. Study Design: Cross-sectional, observational study. Place and Duration of Study: Multi-centre study, conducted at Liaquat National Hospital and Medical College, National Medical Centre and Medicare Hospital, Karachi, from January to October 2009. Methodology: Patients attending the Orthopaedic OPDs with complaints of pain in different body regions and serum vitamin D/sub 3/ levels of greater or equal to 30 ng/ml were included in the study. Patients with vitamin D deficiency were further categorized into mild deficiency or insufficiency (vit. D/sub 3/ = 20-29 ng/ml), moderate deficiency (vit. D/sub 3/ = 5 - 19 ng/ml) and severe deficiency forms (vit. D/sub 3/ < 5 ng/ml). Pearson correlation was applied to test the correlation of serum alkaline phosphatase levels with serum vitamin D/sub 3/ levels. P-value < 0.05 was considered to be significant. Results: Out of 110 samples, 26 had mild (23%), 61 had moderate (55%) and 21 had severe (19.1%) vitamin D deficiencies. All of the patients in the three groups had alkaline phosphatase with in normal limits and the total mean value of the enzyme was 135.97 +- 68.14I U/L. The inter group comparison showed highest values of alkaline phosphatase in the moderate vitamin D deficiency group. The correlation coefficient of alkaline phosphatase and serum vitamin D/sub 3/ levels was r =0.05 (p =0.593). Conclusion: Serum vitamin D/sub 3/ levels may not be correlated with increased serum alkaline phosphatase levels. Therefore, alkaline phosphatase may not be used as a screening test to rule out vitamin D deficiency. (author)

Hysteroscopic Differences in the Gestational Sac in Asymptomatic Blighted Ovum and Viable Pregnancy at Early Gestation

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Fu-Tsai Kung

2005-12-01

Conclusions: The anatomic alterations of the gestational sac reflect impending sac necrosis and abortion in early-stage pregnancy loss. There were no morphologic differences between the two groups in the pattern of capillary distribution on the endometrium or the implantation base.

Posttranslational heterogeneity of bone alkaline phosphatase in metabolic bone disease.

Science.gov (United States)

Langlois, M R; Delanghe, J R; Kaufman, J M; De Buyzere, M L; Van Hoecke, M J; Leroux-Roels, G G

1994-09-01

Bone alkaline phosphatase is a marker of osteoblast activity. In order to study the posttranscriptional modification (glycosylation) of bone alkaline phosphatase in bone disease, we investigated the relationship between mass and catalytic activity of bone alkaline phosphatase in patients with osteoporosis and hyperthyroidism. Serum bone alkaline phosphatase activity was measured after lectin precipitation using the Iso-ALP test kit. Mass concentration of bone alkaline phosphatase was determined with an immunoradiometric assay (Tandem-R Ostase). In general, serum bone alkaline phosphatase mass and activity concentration correlated well. The activity : mass ratio of bone alkaline phosphatase was low in hyperthyroidism. Activation energy of the reaction catalysed by bone alkaline phosphatase was high in osteoporosis and in hyperthyroidism. Experiments with neuraminidase digestion further demonstrated that the thermodynamic heterogeneity of bone alkaline phosphatase can be explained by a different glycosylation of the enzyme.

Initial clinical experience with a sac-anchoring endoprosthesis for aortic aneurysm repair.

Science.gov (United States)

Donayre, Carlos E; Zarins, Christopher K; Krievins, Dainis K; Holden, Andrew; Hill, Andrew; Calderas, Carlos; Velez, Jaime; White, Rodney A

2011-03-01

All current aortic endografts depend on proximal and distal fixation to prevent migration. However, migration and rupture can occur, particularly in patients with aortic necks that are short or angulated, or both. We present our initial clinical experience with a new sac-anchoring endoprosthesis designed to anchor and seal the device within the aneurysm sac. The initial worldwide experience using a new endoprosthesis for the treatment of aortic aneurysms (Nellix Endovascular, Palo Alto, Calif) was reviewed. The endoprosthesis consists of dual balloon-expandable endoframes surrounded by polymer-filled endobags designed to obliterate the aneurysm sac and maintain endograft position. Clinical results and follow-up contrast computed tomography (CT) scans at 30 days and 6 and 12 months were reviewed. The endograft was successfully deployed in 21 patients with infrarenal aortic aneurysms measuring 5.7 ± 0.7 cm (range, 4.3-7.4 cm). Two patients with common iliac aneurysms were treated with sac-anchoring extenders that maintained patency of the internal iliac artery. Infusion of 71 ± 37 mL of polymer (range, 19-158 mL) into the aortic endobags resulted in complete aneurysm exclusion in all patients. Mean implant time was 76 ± 35 minutes, with 33 ± 17 minutes of fluoroscopy time and 180 ± 81 mL of contrast; estimated blood loss was 174 ± 116 mL. One patient died during the postoperative period (30-day mortality, 4.8%), and one died at 10 months from non-device-related causes. During a mean follow-up of 8.7 ± 3.1 months and a median of 6.3 months, there were no late aneurysm- or device-related adverse events and no secondary procedures. CT imaging studies at 6 months and 1 year revealed no increase in aneurysm size, no device migration, and no new endoleaks. One patient had a limited proximal type I endoleak at 30 days that resolved at 60 days and remained sealed. One patient has an ongoing distal type I endoleak near the iliac bifurcation, with no change in aneurysm

Phosphatase control of 4E-BP1 phosphorylation state is central for glycolytic regulation of retinal protein synthesis.

Science.gov (United States)

Gardner, Thomas W; Abcouwer, Steven F; Losiewicz, Mandy K; Fort, Patrice E

2015-09-15

Control of protein synthesis in insulin-responsive tissues has been well characterized, but relatively little is known about how this process is regulated in nervous tissues. The retina exhibits a relatively high protein synthesis rate, coinciding with high basal Akt and metabolic activities, with the majority of retinal ATP being derived from aerobic glycolysis. We examined the dependency of retinal protein synthesis on the Akt-mTOR signaling and glycolysis using ex vivo rat retinas. Akt inhibitors significantly reduced retinal protein synthesis but did not affect glycolytic lactate production. Surprisingly, the glycolytic inhibitor 2-deoxyglucose (2-DG) markedly inhibited Akt1 and Akt3 activities, as well as protein synthesis. The effects of 2-DG, and 2-fluorodeoxyglucose (2-FDG) on retinal protein synthesis correlated with inhibition of lactate production and diminished ATP content, with all these effects reversed by provision of d-mannose. 2-DG treatment was not associated with increased AMPK, eEF2, or eIF2α phosphorylation; instead, it caused rapid dephosphorylation of 4E-BP1. 2-DG reduced total mTOR activity by 25%, but surprisingly, it did not reduce mTORC1 activity, as indicated by unaltered raptor-associated mTOR autophosphorylation and ribosomal protein S6 phosphorylation. Dephosphorylation of 4E-BP1 was largely prevented by inhibition of PP1/PP2A phosphatases with okadaic acid and calyculin A, and inhibition of PPM1 phosphatases with cadmium. Thus, inhibition of retinal glycolysis diminished Akt and protein synthesis coinciding with accelerated dephosphorylation of 4E-BP1 independently of mTORC1. These results demonstrate a novel mechanism regulating protein synthesis in the retina involving an mTORC1-independent and phosphatase-dependent regulation of 4E-BP1. Copyright © 2015 the American Physiological Society.

Planeamiento estratégico de la empresa ABR Lagos S.A.C.

OpenAIRE

Zuloeta Lagos, Bujarin Jaime

2016-01-01

La presente investigación tiene por finalidad desarrollar un Plan Estratégico para la empresa ABR Lagos S.A.C. para el periodo 2016-2020, con lo cual se busca consolidar su permanencia en el mercado peruano, incrementar su rentabilidad y mejorar la calidad del servicio. ABR Lagos S.A.C. es una empresa especializada en la fabricación e instalación de estructuras metálicas, la cual con casi siete años en el mercado ha mostrado un significativo crecimiento en las ventas. Para el logro del objeti...

Performance analysis for the bit-error rate of SAC-OCDMA systems

Science.gov (United States)

Feng, Gang; Cheng, Wenqing; Chen, Fujun

2015-09-01

Under low power, Gaussian statistics by invoking the central limit theorem is feasible to predict the upper bound in the spectral-amplitude-coding optical code division multiple access (SAC-OCDMA) system. However, this case severely underestimates the bit-error rate (BER) performance of the system under high power assumption. Fortunately, the exact negative binomial (NB) model is a perfect replacement for the Gaussian model in the prediction and evaluation. Based on NB statistics, a more accurate closed-form expression is analyzed and derived for the SAC-OCDMA system. The experiment shows that the obtained expression provides a more precise prediction of the BER performance under the low and high power assumptions.

Primary root protophloem differentiation requires balanced phosphatidylinositol-4,5-biphosphate levels and systemically affects root branching.

OpenAIRE

Rodriguez-Villalon Antia; Gujas Bojan; van Wijk Ringo; Munnik Teun; Hardtke Christian S

2015-01-01

Protophloem is a specialized vascular tissue in growing plant organs, such as root meristems. In Arabidopsis mutants with impaired primary root protophloem differentiation, brevis radix (brx) and octopus (ops), meristematic activity and consequently overall root growth are strongly reduced. Second site mutation in the protophloem-specific presumed phosphoinositide 5-phosphatase cotyledon vascular pattern 2 (CVP2), but not in its homolog CVP2-like 1 (CVL1), partially rescues brx defects. Consi...

TMACS Test Procedure TP008: SACS Interface. Revision 5

International Nuclear Information System (INIS)

Washburn, S.J.

1994-01-01

The TMACS Software Project Test Procedures translate the project's acceptance criteria into test steps. Software releases are certified when the affected Test Procedures are successfully performed and the customers authorize installation of these changes. This Test Procedure tests the TMACS SACS Interface functions

Vanillic acid derivatives from the green algae Cladophora socialis as potent protein tyrosine phosphatase 1B inhibitors.

Science.gov (United States)

Feng, Yunjiang; Carroll, Anthony R; Addepalli, Rama; Fechner, Gregory A; Avery, Vicky M; Quinn, Ronald J

2007-11-01

A novel vanillic acid derivative (1) and its sulfate adduct (2) were isolated from a green algae, Cladophora socialis. The structures of 1 and 2 were elucidated from NMR and HRESIMS experiments. Both compounds showed potent inhibitory activity against protein tyrosine phosphatase 1B (PTP1B), an enzyme involved in the regulation of insulin cell signaling. Compounds 1 and 2 had IC50 values of 3.7 and 1.7 microM, respectively.

Kappa opioid receptors stimulate phosphoinositide turnover in rat brain

Energy Technology Data Exchange (ETDEWEB)

Periyasamy, S.; Hoss, W. (Univ. of Toledo, OH (USA))

1990-01-01

The effects of various subtype-selective opioid agonists and antagonists on the phosphoinositide (PI) turnover response were investigated in the rat brain. The {kappa}-agonists U-50,488H and ketocyclazocine produced a concentration-dependent increase in the accumulation of IP's in hippocampal slices. The other {kappa}-agonists Dynorphin-A (1-13) amide, and its protected analog D(Ala){sup 2}-dynorphin-A (1-13) amide also produced a significant increase in the formation of ({sup 3}H)-IP's, whereas the {mu}-selective agonists (D-Ala{sup 2}-N-Me-Phe{sup 4}-Gly{sup 5}-ol)-enkephalin and morphine and the {delta}-selective agonist (D-Pen{sup 2,5})-enkephalin were ineffective. The increase in IP's formation elicited by U-50,488H was partially antagonized by naloxone and more completely antagonized by the {kappa}-selective antagonists nor-binaltorphimine and MR 2266. The formation of IP's induced by U-50,488H varies with the regions of the brain used, being highest in hippocampus and amygdala, and lowest in striatum and pons-medullar. The results indicate that brain {kappa}- but neither {mu}- nor {delta}- receptors are coupled to the PI turnover response.

The wip1 phosphatase (PPM1D) antagonizes activation of the CHK2 tumor suppressor kinase

Energy Technology Data Exchange (ETDEWEB)

Manet, Oliva-Trastoy; Berthonaud, V.; Chevalier, A.; Ducrot, C.; Marsolier-Kergoat, M.C.; Mann, C.; Leteurtre, F. [CEA Saclay, DSV, DBJC, SBGM, Lab. du Controle du Cycle Cellulaire, 91 - Gif-sur-Yvette (France)

2006-07-01

adaptation). Our group previously demonstrated that type 2C protein phosphatases (PP2C) Ptc2 and Ptc3 are required for DNA checkpoint inactivation after DNA double-strand break repair or adaptation in S. cerevisiae. Here we show the conservation of this pathway in mammalian cells. In response to DNA damage, ATM (ataxia telangiectasia mutated) phosphorylates the Chk2 tumor suppressor kinase at threonine 68 (Thr68), allowing Chk2 kinase dimerization and activation by auto-phosphorylations in the T-loop. The oncogenic protein Wip1, a PP2C phosphatase, binds Chk2 and de-phosphorylates phospho-Thr68. Consequently, Wip1 opposes Chk2 activation by ATM after ionizing irradiation of cells. The recombinant Chk2 protein is fully phosphorylated and activated, due to the high protein concentrations obtained during production. In vitro, Wip 1 de-phosphorylates the phospho-T68 of Chk2, but does not reduce Chk2 kinase activity on its usual GST-CDC25C substrate. These observations suggest that Wip1 phosphatase controls Chk2 activation rather than its enzymatic activity that relies on phosphorylations in the T-loop. The physiological consequences of Wip1 overexpression were tested in human adenocarcinoma cells: the HCT15 cell line. The specificities of this cell line are (i ) the absence of functional p53 proteins, leading to a G2 delay in response to a genotoxic stress, and (ii) the absence of functional Chk2 proteins, because of one CHK2 allele being unexpressed and because the second allele codes for a mutated protein that is unstable and inactive. The HCT15 cell line was complemented by a functional form of HA-Chk2 and the selected clone expresses the protein to a level similar to that observed in other cell lines. In HCT15 colorectal cancer cells corrected for functional Chk2 activity, Wip 1 modest overexpression suppressed the contribution of Chk2 to the G2/M DNA damage checkpoint. These results indicate that Wip1 is one of the phosphatases regulating the activity of Chk2 in response to

The wip1 phosphatase (PPM1D) antagonizes activation of the CHK2 tumor suppressor kinase

International Nuclear Information System (INIS)

Manet, Oliva-Trastoy; Berthonaud, V.; Chevalier, A.; Ducrot, C.; Marsolier-Kergoat, M.C.; Mann, C.; Leteurtre, F.

2006-01-01

). Our group previously demonstrated that type 2C protein phosphatases (PP2C) Ptc2 and Ptc3 are required for DNA checkpoint inactivation after DNA double-strand break repair or adaptation in S. cerevisiae. Here we show the conservation of this pathway in mammalian cells. In response to DNA damage, ATM (ataxia telangiectasia mutated) phosphorylates the Chk2 tumor suppressor kinase at threonine 68 (Thr68), allowing Chk2 kinase dimerization and activation by auto-phosphorylations in the T-loop. The oncogenic protein Wip1, a PP2C phosphatase, binds Chk2 and de-phosphorylates phospho-Thr68. Consequently, Wip1 opposes Chk2 activation by ATM after ionizing irradiation of cells. The recombinant Chk2 protein is fully phosphorylated and activated, due to the high protein concentrations obtained during production. In vitro, Wip 1 de-phosphorylates the phospho-T68 of Chk2, but does not reduce Chk2 kinase activity on its usual GST-CDC25C substrate. These observations suggest that Wip1 phosphatase controls Chk2 activation rather than its enzymatic activity that relies on phosphorylations in the T-loop. The physiological consequences of Wip1 overexpression were tested in human adenocarcinoma cells: the HCT15 cell line. The specificities of this cell line are (i ) the absence of functional p53 proteins, leading to a G2 delay in response to a genotoxic stress, and (ii) the absence of functional Chk2 proteins, because of one CHK2 allele being unexpressed and because the second allele codes for a mutated protein that is unstable and inactive. The HCT15 cell line was complemented by a functional form of HA-Chk2 and the selected clone expresses the protein to a level similar to that observed in other cell lines. In HCT15 colorectal cancer cells corrected for functional Chk2 activity, Wip 1 modest overexpression suppressed the contribution of Chk2 to the G2/M DNA damage checkpoint. These results indicate that Wip1 is one of the phosphatases regulating the activity of Chk2 in response to DNA

Protein phosphatase PPM1G regulates protein translation and cell growth by dephosphorylating 4E binding protein 1 (4E-BP1).

Science.gov (United States)

Liu, Jianyu; Stevens, Payton D; Eshleman, Nichole E; Gao, Tianyan

2013-08-09

Protein translation initiation is a tightly controlled process responding to nutrient availability and mitogen stimulation. Serving as one of the most important negative regulators of protein translation, 4E binding protein 1 (4E-BP1) binds to translation initiation factor 4E and inhibits cap-dependent translation in a phosphorylation-dependent manner. Although it has been demonstrated previously that the phosphorylation of 4E-BP1 is controlled by mammalian target of rapamycin in the mammalian target of rapamycin complex 1, the mechanism underlying the dephosphorylation of 4E-BP1 remains elusive. Here, we report the identification of PPM1G as the phosphatase of 4E-BP1. A coimmunoprecipitation experiment reveals that PPM1G binds to 4E-BP1 in cells and that purified PPM1G dephosphorylates 4E-BP1 in vitro. Knockdown of PPM1G in 293E and colon cancer HCT116 cells results in an increase in the phosphorylation of 4E-BP1 at both the Thr-37/46 and Ser-65 sites. Furthermore, the time course of 4E-BP1 dephosphorylation induced by amino acid starvation or mammalian target of rapamycin inhibition is slowed down significantly in PPM1G knockdown cells. Functionally, the amount of 4E-BP1 bound to the cap-dependent translation initiation complex is decreased when the expression of PPM1G is depleted. As a result, the rate of cap-dependent translation, cell size, and protein content are increased in PPM1G knockdown cells. Taken together, our study has identified protein phosphatase PPM1G as a novel regulator of cap-dependent protein translation by negatively controlling the phosphorylation of 4E-BP1.

Evaluation of Refractivity Profiles from CHAMP and SAC-C GPS Radio Occultation

Science.gov (United States)

Poli, Paul; Ao, Chi On; Joiner, Joanna; delaTorreJuarez, Manuel; Hoff, Raymond

2002-01-01

The GeoForschungsZentrum's Challenging Minisatellite Payload for Geophysical Research and Application (CHAMP, Germany-US) and the Comision Nacional de Actividades Especiales' Satelite de Aplicaciones Cientificas-C (SAC-C, Argentina-US) missions are the first missions to carry a second-generation Blackjack Global Positioning System (GPS) receiver. One of the new features of this receiver is its ability to sense the lower troposphere closer to the surface than the proof-of-concept GPS Meteorology experiment (GPS/MET). Since their launch, CHAMP and SAC-C have collected thousands of GPS radio occultations, representing a wealth of measurements available for data assimilation and Numerical Weather Prediction (NWP). In order to evaluate the refractivity data derived by the Jet Propulsion Laboratory (JPL) from raw radio occultation measurements, we use Data Assimilation Office (DAO) 6-hour forecasts as an independent state of the atmosphere. We compare CHAMP and SAC-C refractivity (processed by JPL) with refractivity calculated from the DAO global fields of temperature, water vapor content and humidity. We show statistics of the differences as well as histograms of the differences.

Asperentin B, a New Inhibitor of the Protein Tyrosine Phosphatase 1B.

Science.gov (United States)

Wiese, Jutta; Aldemir, Hülya; Schmaljohann, Rolf; Gulder, Tobias A M; Imhoff, Johannes F

2017-06-21

In the frame of studies on secondary metabolites produced by fungi from deep-sea environments we have investigated inhibitors of enzymes playing key roles in signaling cascades of biochemical pathways relevant for the treatment of diseases. Here we report on a new inhibitor of the human protein tyrosine phosphatase 1B (PTP1B), a target in the signaling pathway of insulin. A new asperentin analog is produced by an Aspergillus sydowii strain isolated from the sediment of the deep Mediterranean Sea. Asperentin B ( 1 ) contains an additional phenolic hydroxy function at C-6 and exhibits an IC 50 value against PTP1B of 2 μM in vitro, which is six times stronger than the positive control, suramin. Interestingly, asperentin ( 2 ) did not show any inhibition of this enzymatic activity. Asperentin B ( 1 ) is discussed as possible therapeutic agents for type 2 diabetes and sleeping sickness.

Desmoid tumor within lesser sac

Directory of Open Access Journals (Sweden)

Čolović Radoje

2006-01-01

Full Text Available Desmoid tumors or fibromatoses comprise a number of benign fibrous proliferative lesions that have local infiltrative growth and tendency to recur after incomplete excision. They never metastasize. The authors present a 31-year old woman who, due to epigastric pain and palpable mass detected on presentation, underwent the excision of firm tumorous mass, 210x140x115mm in diameter, from the lesser sac. Compressing the splenic vein, the tumor caused left-sided portal hypertension which subsided after the mass was removed. The recovery was uneventful. The histological examination verified typical desmoid tumor. Twelve years after surgery, the patient remained symptom-free with no signs of recurrence.

An unusual foreign body in the preputial sac.

Science.gov (United States)

Jaiswal, A K

1992-01-01

A 28 year old Indian male presented with an unusual foreign body, a penicillin bottle containing tincture of iodine, in the preputial sac. The purpose of introducing the bottle was to tickle his glans penis as a form of masturbation. The bottle was so firmly impacted that it could be removed only under general anaesthesia. Images PMID:1427809

Simplified preparation of a phosphatase inhibitor and further studies of its action.

Science.gov (United States)

Coburn, S P; Schaltenbrand, W E

1978-05-01

1-Pyrrolidinecarbothioic acid (2-pyridylmethylene) hydrazide chelates Zn2+ but not Mg2+. This compound is about twice as effective as EDTA for inhibiting alkaline phosphatase from calf mucosa, and approx. 1000-fold more effective than EDTA for inhibiting acid phosphatase from wheat germ. The compound did not inhibit pyridoxine kinase activity in human leucocytes at the highest concentration tested (33 micron). Therefore it may be a useful tool for either examining or eliminating the effects of phosphatases in complex enzyme systems.

Mechanism of protein tyrosine phosphatase 1B-mediated inhibition of leptin signalling

DEFF Research Database (Denmark)

Lund, I K; Hansen, J A; Andersen, H S

2005-01-01

Upon leptin binding, the leptin receptor is activated, leading to stimulation of the JAK/STAT signal transduction cascade. The transient character of the tyrosine phosphorylation of JAK2 and STAT3 suggests the involvement of protein tyrosine phosphatases (PTPs) as negative regulators...

Cdk1 and okadaic acid-sensitive phosphatases control assembly of nuclear pore complexes in Drosophila embryos.

Science.gov (United States)

Onischenko, Evgeny A; Gubanova, Natalia V; Kiseleva, Elena V; Hallberg, Einar

2005-11-01

Disassembly and reassembly of the nuclear pore complexes (NPCs) is one of the major events during open mitosis in higher eukaryotes. However, how this process is controlled by the mitotic machinery is not clear. To investigate this we developed a novel in vivo model system based on syncytial Drosophila embryos. We microinjected different mitotic effectors into the embryonic cytoplasm and monitored the dynamics of disassembly/reassembly of NPCs in live embryos using fluorescently labeled wheat germ agglutinin (WGA) or in fixed embryos using electron microscopy and immunostaining techniques. We found that in live embryos Cdk1 activity was necessary and sufficient to induce disassembly of NPCs as well as their cytoplasmic mimics: annulate lamellae pore complexes (ALPCs). Cdk1 activity was also required for keeping NPCs and ALPCs disassembled during mitosis. In agreement recombinant Cdk1/cyclin B was able to induce phosphorylation and dissociation of nucleoporins from the NPCs in vitro. Conversely, reassembly of NPCs and ALPCs was dependent on the activity of protein phosphatases, sensitive to okadaic acid (OA). Our findings suggest a model where mitotic disassembly/reassembly of the NPCs is regulated by a dynamic equilibrium of Cdk1 and OA-sensitive phosphatase activities and provide evidence that mitotic phosphorylation mediates disassembly of the NPC.

Structure determination of T-cell protein-tyrosine phosphatase

DEFF Research Database (Denmark)

Iversen, L.F.; Møller, K. B.; Pedersen, A.K.

2002-01-01

Protein-tyrosine phosphatase 1B (PTP1B) has recently received much attention as a potential drug target in type 2 diabetes. This has in particular been spurred by the finding that PTP1B knockout mice show increased insulin sensitivity and resistance to diet-induced obesity. Surprisingly, the highly...... homologous T cell protein-tyrosine phosphatase (TC-PTP) has received much less attention, and no x-ray structure has been provided. We have previously co-crystallized PTP1B with a number of low molecular weight inhibitors that inhibit TC-PTP with similar efficiency. Unexpectedly, we were not able to co...... the high degree of functional and structural similarity between TC-PTP and PTP1B, we have been able to identify areas close to the active site that might be addressed to develop selective inhibitors of each enzyme....

Estrategias de desarrollo para la empresa Cal del Centro S.A.C.

OpenAIRE

Bautista Antón, Yovanni Patricia; Mendoza Rojas, Miguel Ángel

2015-01-01

Cal del Centro S.A.C. es una sociedad anónima cerrada cuyo negocio gira en torno a la actividad económica de la fabricación de cemento, cal y yeso. El objetivo del presente trabajo es evaluar la posibilidad de éxito de un proyecto de inversión en una planta de cal, a través de Cal del Centro S.A.C. –como empresa autosuficiente–, para asegurar el cien por ciento del suministro de óxido de calcio en cantidad y calidad para el procesamiento de concentrados de cobre y el tratamiento de aguas indu...

The heterotrimeric G protein Gβ1 interacts with the catalytic subunit of protein phosphatase 1 and modulates G protein-coupled receptor signaling in platelets.

Science.gov (United States)

Pradhan, Subhashree; Khatlani, Tanvir; Nairn, Angus C; Vijayan, K Vinod

2017-08-11

Thrombosis is caused by the activation of platelets at the site of ruptured atherosclerotic plaques. This activation involves engagement of G protein-coupled receptors (GPCR) on platelets that promote their aggregation. Although it is known that protein kinases and phosphatases modulate GPCR signaling, how serine/threonine phosphatases integrate with G protein signaling pathways is less understood. Because the subcellular localization and substrate specificity of the catalytic subunit of protein phosphatase 1 (PP1c) is dictated by PP1c-interacting proteins, here we sought to identify new PP1c interactors. GPCRs signal via the canonical heterotrimeric Gα and Gβγ subunits. Using a yeast two-hybrid screen, we discovered an interaction between PP1cα and the heterotrimeric G protein Gβ 1 subunit. Co-immunoprecipitation studies with epitope-tagged PP1c and Gβ 1 revealed that Gβ 1 interacts with the PP1c α, β, and γ1 isoforms. Purified PP1c bound to recombinant Gβ 1 -GST protein, and PP1c co-immunoprecipitated with Gβ 1 in unstimulated platelets. Thrombin stimulation of platelets induced the dissociation of the PP1c-Gβ 1 complex, which correlated with an association of PP1c with phospholipase C β3 (PLCβ3), along with a concomitant dephosphorylation of the inhibitory Ser 1105 residue in PLCβ3. siRNA-mediated depletion of GNB1 (encoding Gβ 1 ) in murine megakaryocytes reduced protease-activated receptor 4, activating peptide-induced soluble fibrinogen binding. Thrombin-induced aggregation was decreased in PP1cα -/- murine platelets and in human platelets treated with a small-molecule inhibitor of Gβγ. Finally, disruption of PP1c-Gβ 1 complexes with myristoylated Gβ 1 peptides containing the PP1c binding site moderately decreased thrombin-induced human platelet aggregation. These findings suggest that Gβ 1 protein enlists PP1c to modulate GPCR signaling in platelets.

MR imaging features and clinical value of vestibular aqueduct and endolymphatic sac in patients with large vestibular aqueduct syndrome

International Nuclear Information System (INIS)

Fang Zheming; Lou Xin; Lan Lan; Wang Hui; Wang Qiuju; Wu Nanzhou; Zhang Xiaojing

2012-01-01

Objective: To investigate MR imaging features of endolymphatic sac and vestibular aqueduct in patients with large vestibular aqueduct syndrome (LVAS) and its correlation with hearing loss. Methods: MR imaging findings of LVAS were analyzed in 31 cases (62 ears) retrospectively. MR imaging features were grouped into 4 types. In the first type, the signals of endolymphatic and vestibular aqueduct were hypointense without any hyperintense area. In the second type, the signals of endolymphatic sac and vestibular were hyperintense which were confined within vestibular fissure. In the third type, the area from vestibular aqueduct backward out of the edge of the petrous bone was hyperintense, but its lower boundary was above posterior semicircular. In the fourth type the area which was hyperintense was below the posterior semicircular. To avoid errors in visual inspection, the hyperintense and hypointense area of endolymphatic and the signal intensity of vestibular aqueduct and cerebrospinal fluid (CSF) were measured. The differences of signal intensity among the vestibular endolymphatic sac between the high-signal areas and low signal areas were compared with paired t-test. The correlation of the endolymphatic sac MRI classification and degree of hearing loss was analyzed by corrected Chi-square test and Spearman correlation analysis. Result: Ten ears belonged to type Ⅰ (moderate hearing loss in 1 ear,severe in 4 ears,profound in 5 ears), 17 ears belonged to type Ⅱ (moderate hearing loss in 1 ear; severe in 5 ears,profound in 11 ears), 23 ears to type Ⅲ (moderate hearing loss in 3 ear, severe in 5 ears, profound in 15 ears) and 12 ears belonged to Ⅳ (mild hearing loss in 1 ear, moderate in 1 ear, severe 3 ear, profound in 7 ears). The boundary between hyperintense and hypointense area was clear, and the signal intensity ratios was 2.02 ± 0.06. The signal ratios of hyperintense and hypointense area to vestibular and CSF were 0.95 ±0.12, 0.49 ±0.10, 0.99 ± 0

Endometrial carcinoma with yolk sac tumor-like differentiation and elevated serum ß-hCG: a case report and literature review

Directory of Open Access Journals (Sweden)

Ji M

2013-10-01

Full Text Available Mingliang Ji,1 Yan Lu,1 Lina Guo,2 Fengzhi Feng,1 Xirun Wan,1 Yang Xiang1 1Department of Obstetrics and Gynecology, 2Department of Pathology, Peking Union Medical College Hospital, Beijing, People's Republic of China Abstract: Endometrial carcinoma with a germ cell tumor component is a rare event. Here we report a uterine neoplasm with a unique combination of endometrioid adenocarcinoma and mixed germ cell malignant elements. A 28-year-old woman with abnormal vaginal bleeding, an abdominal mass, and elevated alfa-fetoprotein and beta-human chorionic gonadotropin (ß-hCG levels had a history of biopsy of an omental mass and chemotherapy in another hospital one month before her referral to our department. Histologic examination of the mass removed from the omentum revealed an endometrioid adenocarcinoma with yolk sac tumor-like differentiation. Total abdominal hysterectomy, bilateral salpingo-oophorectomy, infracolic omentectomy, and removal of metastatic disease were then undertaken at our hospital. Postoperative chemotherapy was given. Eight months postoperatively, serum alfa-fetoprotein and ß-hCG rose again. Cases with primary yolk sac tumors of the endometrium or endometrial carcinoma with trophoblastic differentiation in the literature were reviewed. Keywords: endometrial carcinoma, yolk sac tumor, trophoblastic differentiation

The ApaH-like phosphatase TbALPH1 is the major mRNA decapping enzyme of trypanosomes.

Directory of Open Access Journals (Sweden)

Susanne Kramer

2017-06-01

Full Text Available 5'-3' decay is the major mRNA decay pathway in many eukaryotes, including trypanosomes. After deadenylation, mRNAs are decapped by the nudix hydrolase DCP2 of the decapping complex and finally degraded by the 5'-3' exoribonuclease. Uniquely, trypanosomes lack homologues to all subunits of the decapping complex, while deadenylation and 5'-3' degradation are conserved. Here, I show that the parasites use an ApaH-like phosphatase (ALPH1 as their major mRNA decapping enzyme. The protein was recently identified as a novel trypanosome stress granule protein and as involved in mRNA binding. A fraction of ALPH1 co-localises exclusively with the trypanosome 5'-3' exoribonuclease XRNA to a special granule at the posterior pole of the cell, indicating a connection between the two enzymes. RNAi depletion of ALPH1 is lethal and causes a massive increase in total mRNAs that are deadenylated, but have not yet started 5'-3' decay. These data suggest that ALPH1 acts downstream of deadenylation and upstream of mRNA degradation, consistent with a function in mRNA decapping. In vitro experiments show that recombinant, N-terminally truncated ALHP1 protein, but not a catalytically inactive mutant, sensitises the capped trypanosome spliced leader RNA to yeast Xrn1, but only if an RNA 5' polyphosphatase is included. This indicates that the decapping mechanism of ALPH1 differs from the decapping mechanism of Dcp2 by leaving more than one phosphate group at the mRNA's 5' end. This is the first reported function of a eukaryotic ApaH-like phosphatase, a bacterial-derived class of enzymes present in all phylogenetic super-groups of the eukaryotic kingdom. The substrates of eukaryotic ApaH-like phosphatases are unknown. However, the substrate of the related bacterial enzyme ApaH, diadenosine tetraphosphate, is highly reminiscent of a eukaryotic mRNA cap.

Increased liver alkaline phosphatase and aminotransferase ...

African Journals Online (AJOL)

The effect of daily, oral administration of ethanolic extract of Khaya senegalensis stem bark (2mg/kg body weight) for 18days on the alkaline phosphatase, aspartate and alanine aminotransferase activities of rat liver and serum were investigated. Compared with the control, the activities of liver alkaline phosphatase (ALP), ...

Purification and properties of acid phosphatase from Avena elatior L. seeds

Directory of Open Access Journals (Sweden)

E. Wieczorek

2015-01-01

Full Text Available Acid phosphatase F1 from Avena elatior seeds was isolated and partially purified by means of alcohol precepitation, DEAE-, CM-column chromatography, Sephadex G-150, Sephadex G-200 and Sepharose 4B - gel filtration. The enzyme was stable at 50°C, pH 5.1. The pH optimum for phosphatase activity was 4.2. Fluoride, Zn2+, molybdate were effective inhibitors. EDTA and l, 10-phenanthroline activated the enzyme.

Synaptojanin 1 is required for endolysosomal trafficking of synaptic proteins in cone photoreceptor inner segments.

Directory of Open Access Journals (Sweden)

Ashley A George

Full Text Available Highly polarized cells such as photoreceptors require precise and efficient strategies for establishing and maintaining the proper subcellular distribution of proteins. The signals and molecular machinery that regulate trafficking and sorting of synaptic proteins within cone inner segments is mostly unknown. In this study, we show that the polyphosphoinositide phosphatase Synaptojanin 1 (SynJ1 is critical for this process. We used transgenic markers for trafficking pathways, electron microscopy, and immunocytochemistry to characterize trafficking defects in cones of the zebrafish mutant, nrc(a14 , which is deficient in phosphoinositide phosphatase, SynJ1. The outer segments and connecting cilia of nrc(a14 cone photoreceptors are normal, but RibeyeB and VAMP2/synaptobrevin, which normally localize to the synapse, accumulate in the nrc(a14 inner segment. The structure of the Endoplasmic Reticulum in nrc(a14 mutant cones is normal. Golgi develop normally, but later become disordered. Large vesicular structures accumulate within nrc(a14 cone photoreceptor inner segments, particularly after prolonged incubation in darkness. Cone inner segments of nrc (a14 mutants also have enlarged acidic vesicles, abnormal late endosomes, and a disruption in autophagy. This last pathway also appears exacerbated by darkness. Taken altogether, these findings show that SynJ1 is required in cones for normal endolysosomal trafficking of synaptic proteins.

Phosphoinositide-3-kinase activation controls synaptogenesis and spinogenesis in hippocampal neurons.

Science.gov (United States)

Cuesto, Germán; Enriquez-Barreto, Lilian; Caramés, Cristina; Cantarero, Marta; Gasull, Xavier; Sandi, Carmen; Ferrús, Alberto; Acebes, Ángel; Morales, Miguel

2011-02-23

The possibility of changing the number of synapses may be an important asset in the treatment of neurological diseases. In this context, the synaptogenic role of the phosphoinositide-3-kinase (PI3K) signaling cascade has been previously demonstrated in Drosophila. This study shows that treatment with a PI3K-activating transduction peptide is able to promote synaptogenesis and spinogenesis in primary cultures of rat hippocampal neurons, as well as in CA1 hippocampal neurons in vivo. In culture, the peptide increases synapse density independently of cell density, culture age, dendritic complexity, or synapse type. The induced synapses also increase neurotransmitter release from cultured neurons. The synaptogenic signaling pathway includes PI3K-Akt. Furthermore, the treatment is effective on adult neurons, where it induces spinogenesis and enhances the cognitive behavior of treated animals in a fear-conditioning assay. These findings demonstrate that functional synaptogenesis can be induced in mature mammalian brains through PI3K activation.

Dynamic Changes in Yeast Phosphatase Families Allow for Specialization in Phosphate and Thiamine Starvation.

Science.gov (United States)

Nahas, John V; Iosue, Christine L; Shaik, Noor F; Selhorst, Kathleen; He, Bin Z; Wykoff, Dennis D

2018-05-10

Convergent evolution is often due to selective pressures generating a similar phenotype. We observe relatively recent duplications in a spectrum of Saccharomycetaceae yeast species resulting in multiple phosphatases that are regulated by different nutrient conditions - thiamine and phosphate starvation. This specialization is both transcriptional and at the level of phosphatase substrate specificity. In Candida glabrata , loss of the ancestral phosphatase family was compensated by the co-option of a different histidine phosphatase family with three paralogs. Using RNA-seq and functional assays, we identify one of these paralogs, CgPMU3 , as a thiamine phosphatase. We further determine that the 81% identical paralog CgPMU2 does not encode thiamine phosphatase activity; however, both are capable of cleaving the phosphatase substrate, 1-napthyl-phosphate. We functionally demonstrate that members of this family evolved novel enzymatic functions for phosphate and thiamine starvation, and are regulated transcriptionally by either nutrient condition, and observe similar trends in other yeast species. This independent, parallel evolution involving two different families of histidine phosphatases suggests that there were likely similar selective pressures on multiple yeast species to recycle thiamine and phosphate. In this work, we focused on duplication and specialization, but there is also repeated loss of phosphatases, indicating that the expansion and contraction of the phosphatase family is dynamic in many Ascomycetes. The dynamic evolution of the phosphatase gene families is perhaps just one example of how gene duplication, co-option, and transcriptional and functional specialization together allow species to adapt to their environment with existing genetic resources. Copyright © 2018, G3: Genes, Genomes, Genetics.

Coordinated Regulation of Insulin Signaling by the Protein Tyrosine Phosphatases PTP1B and TCPTP

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Galic, Sandra; Hauser, Christine; Kahn, Barbara B.; Haj, Fawaz G.; Neel, Benjamin G.; Tonks, Nicholas K.; Tiganis, Tony

2005-01-01

The protein tyrosine phosphatase PTP1B is a negative regulator of insulin signaling and a therapeutic target for type 2 diabetes. Our previous studies have shown that the closely related tyrosine phosphatase TCPTP might also contribute to the regulation of insulin receptor (IR) signaling in vivo (S. Galic, M. Klingler-Hoffmann, M. T. Fodero-Tavoletti, M. A. Puryer, T. C. Meng, N. K. Tonks, and T. Tiganis, Mol. Cell. Biol. 23:2096-2108, 2003). Here we show that PTP1B and TCPTP function in a coordinated and temporally distinct manner to achieve an overall regulation of IR phosphorylation and signaling. Whereas insulin-induced phosphatidylinositol 3-kinase/Akt signaling was prolonged in both TCPTP−/− and PTP1B−/− immortalized mouse embryo fibroblasts (MEFs), mitogen-activated protein kinase ERK1/2 signaling was elevated only in PTP1B-null MEFs. By using phosphorylation-specific antibodies, we demonstrate that both IR β-subunit Y1162/Y1163 and Y972 phosphorylation are elevated in PTP1B−/− MEFs, whereas Y972 phosphorylation was elevated and Y1162/Y1163 phosphorylation was sustained in TCPTP−/− MEFs, indicating that PTP1B and TCPTP differentially contribute to the regulation of IR phosphorylation and signaling. Consistent with this, suppression of TCPTP protein levels by RNA interference in PTP1B−/− MEFs resulted in no change in ERK1/2 signaling but caused prolonged Akt activation and Y1162/Y1163 phosphorylation. These results demonstrate that PTP1B and TCPTP are not redundant in insulin signaling and that they act to control both common as well as distinct insulin signaling pathways in the same cell. PMID:15632081

The Arabidopsis thiamin-deficient mutant pale green1 lacks thiamin monophosphate phosphatase of the vitamin B1 biosynthesis pathway.

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Hsieh, Wei-Yu; Liao, Jo-Chien; Wang, Hsin-Tzu; Hung, Tzu-Huan; Tseng, Ching-Chih; Chung, Tsui-Yun; Hsieh, Ming-Hsiun

2017-07-01

Thiamin diphosphate (TPP, vitamin B 1 ) is an essential coenzyme present in all organisms. Animals obtain TPP from their diets, but plants synthesize TPPde novo. We isolated and characterized an Arabidopsis pale green1 (pale1) mutant that contained higher concentrations of thiamin monophosphate (TMP) and less thiamin and TPP than the wild type. Supplementation with thiamin, but not the thiazole and pyrimidine precursors, rescued the mutant phenotype, indicating that the pale1 mutant is a thiamin-deficient mutant. Map-based cloning and whole-genome sequencing revealed that the pale1 mutant has a mutation in At5g32470 encoding a TMP phosphatase of the TPP biosynthesis pathway. We further confirmed that the mutation of At5g32470 is responsible for the mutant phenotypes by complementing the pale1 mutant with constructs overexpressing full-length At5g32470. Most plant TPP biosynthetic enzymes are located in the chloroplasts and cytosol, but At5g32470-GFP localized to the mitochondrion of the root, hypocotyl, mesophyll and guard cells of the 35S:At5g32470-GFP complemented plants. The subcellular localization of a functional TMP phosphatase suggests that the complete vitamin B1 biosynthesis pathway may involve the chloroplasts, mitochondria and cytosol in plants. Analysis of PALE1 promoter-uidA activity revealed that PALE1 is mainly expressed in vascular tissues of Arabidopsis seedlings. Quantitative RT-PCR analysis of TPP biosynthesis genes and genes encoding the TPP-dependent enzymes pyruvate dehydrogenase, α-ketoglutarate dehydrogenase and transketolase revealed that the transcript levels of these genes were upregulated in the pale1 mutant. These results suggest that endogenous levels of TPP may affect the expression of genes involved in TPP biosynthesis and TPP-dependent enzymes. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

EVAR using the Nellix Sac-anchoring endoprosthesis: treatment of favourable and adverse anatomy.

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Krievins, D K; Holden, A; Savlovskis, J; Calderas, C; Donayre, C E; Moll, F L; Katzen, B; Zarins, C K

2011-07-01

The study aimed to review the results of endovascular aneurysm repair (EVAR) using a novel sac-anchoring endoprosthesis in patients with favourable and adverse anatomy. This is a prospective, multicentre, clinical trial. The Nellix endoprosthesis consists of dual, balloon-expandable endoframes, surrounded by polymer-filled endobags, which obliterate the aneurysm sac and maintain endograft position. The study reviewed worldwide clinical experience and Core Lab evaluation of computed tomography (CT) scans. From 2008 to 2010, 34 patients (age 71 ± 8 years, abdominal aortic aneurysm (AAA) diameter 5.8 ± 0.8 cm) were treated at four clinical sites. Seventeen patients (50%) met the inclusion criteria for Food and Drug Administration (FDA)-approved endografts (favourable anatomy); 17 (50%) had one or more adverse anatomic feature: neck length 60° (9%) and iliac diameter >23 mm (38%). Device deployment was successful in all patients; iliac aneurysm treatment preserved hypogastric patency. Perioperative mortality was 1/34 (2.9%); one patient died at 10 months of congestive heart failure (CHF); one patient had a secondary procedure at 15 months. During 15 ± 6 months follow-up, there were no differences in outcome between favourable and adverse anatomy patients. Follow-up CT extending up to 2 years revealed no change in aneurysm size or endograft position and no new endoleaks. Favourable and adverse anatomy patients can be successfully treated using the Nellix sac-anchoring endoprosthesis. Early results are promising but longer-term studies are needed. Copyright © 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Stimulation of phosphoinositide hydrolysis by a novel substance partially purified from rat and bovine brain

International Nuclear Information System (INIS)

Schoepp, D.; Wilson, T.; Elliott, C.; Wright, G.; McCumbee, W.

1986-01-01

This study demonstrates the partial purification of a potentially novel substance from rat and bovine brain. Whole brains were homogenized in distilled water, then heated at 100 0 C for 30 min. The water extract was dialyzed and the 3 H-inositol monophosphate ( 3 H-IP) using lithium-treated slices of rat cerebral cortex prelabelled with 3 H-myo-inositol. A major peak of activity was observed in fractions from the molecular weight range of 800-1300 daltons. Stimulation of phosphoinositide hydrolysis by this material was time-dependent and dose-related. Maximal stimulation of 3 H-IP (323% of control) required 10mg/ml of bovine material and was observed at 30 minutes. These effects could not be mimicked by a number of substances of similar molecular weight (e.g. substance P, neurotensin, angiotensin II, bradykinin). Furthermore, the effects of this material were not blocked by antagonist drugs which act at the alpha-adrenoceptor, muscarinic cholinoceptor, 5-HT2 receptor, substance P receptor, or neurotensin receptor. These results indicate that the substance isolated may be a novel neuroactive molecule which has receptors coupled to phosphoinositide hydrolysis in brain

Modulation of catalytic activity in multi-domain protein tyrosine phosphatases.

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Lalima L Madan

Full Text Available Signaling mechanisms involving protein tyrosine phosphatases govern several cellular and developmental processes. These enzymes are regulated by several mechanisms which include variation in the catalytic turnover rate based on redox stimuli, subcellular localization or protein-protein interactions. In the case of Receptor Protein Tyrosine Phosphatases (RPTPs containing two PTP domains, phosphatase activity is localized in their membrane-proximal (D1 domains, while the membrane-distal (D2 domain is believed to play a modulatory role. Here we report our analysis of the influence of the D2 domain on the catalytic activity and substrate specificity of the D1 domain using two Drosophila melanogaster RPTPs as a model system. Biochemical studies reveal contrasting roles for the D2 domain of Drosophila Leukocyte antigen Related (DLAR and Protein Tyrosine Phosphatase on Drosophila chromosome band 99A (PTP99A. While D2 lowers the catalytic activity of the D1 domain in DLAR, the D2 domain of PTP99A leads to an increase in the catalytic activity of its D1 domain. Substrate specificity, on the other hand, is cumulative, whereby the individual specificities of the D1 and D2 domains contribute to the substrate specificity of these two-domain enzymes. Molecular dynamics simulations on structural models of DLAR and PTP99A reveal a conformational rationale for the experimental observations. These studies reveal that concerted structural changes mediate inter-domain communication resulting in either inhibitory or activating effects of the membrane distal PTP domain on the catalytic activity of the membrane proximal PTP domain.

Downregulation of Wip1 phosphatase modulates the cellular threshold of DNA damage signaling in mitosis

Czech Academy of Sciences Publication Activity Database

Macůrek, Libor; Benada, Jan; Müllers, E.; Halim, V.A.; Krejčíková, Kateřina; Burdová, Kamila; Pecháčková, Soňa; Hodný, Zdeněk; Lindqvist, A.; Medema, R.H.; Bartek, Jiří

2013-01-01

Roč. 12, č. 2 (2013), s. 251-262 ISSN 1538-4101 R&D Projects: GA ČR GPP305/10/P420; GA ČR GAP301/10/1525 Grant - others:Netherlands Genomic Initiative of NWO(NL) CGC; EK(XE) 259893 Institutional support: RVO:68378050 Keywords : DNA damage response * Wip1 phosphatase * cell cycle * mitotic progression * γH2AX Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.006, year: 2013

Protein Tyrosine Phosphatase 1B (PTP1B): A Potential Target for Alzheimer's Therapy?

Science.gov (United States)

Vieira, Marcelo N N; Lyra E Silva, Natalia M; Ferreira, Sergio T; De Felice, Fernanda G

2017-01-01

Despite significant advances in current understanding of mechanisms of pathogenesis in Alzheimer's disease (AD), attempts at drug development based on those discoveries have failed to translate into effective, disease-modifying therapies. AD is a complex and multifactorial disease comprising a range of aberrant cellular/molecular processes taking part in different cell types and brain regions. As a consequence, therapeutics for AD should be able to block or compensate multiple abnormal pathological events. Here, we examine recent evidence that inhibition of protein tyrosine phosphatase 1B (PTP1B) may represent a promising strategy to combat a variety of AD-related detrimental processes. Besides its well described role as a negative regulator of insulin and leptin signaling, PTB1B recently emerged as a modulator of various other processes in the central nervous system (CNS) that are also implicated in AD. These include signaling pathways germane to learning and memory, regulation of synapse dynamics, endoplasmic reticulum (ER) stress and microglia-mediated neuroinflammation. We propose that PTP1B inhibition may represent an attractive and yet unexplored therapeutic approach to correct aberrant signaling pathways linked to AD.

Crystal plasticity finite element analysis of deformation behaviour in SAC305 solder joint

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Darbandi, Payam

Due to the awareness of the potential health hazards associated with the toxicity of lead (Pb), actions have been taken to eliminate or reduce the use of Pb in consumer products. Among those, tin (Sn) solders have been used for the assembly of electronic systems. Anisotropy is of significant importance in all structural metals, but this characteristic is unusually strong in Sn, making Sn based solder joints one of the best examples of the influence of anisotropy. The effect of anisotropy arising from the crystal structure of tin and large grain microstructure on the microstructure and the evolution of constitutive responses of microscale SAC305 solder joints is investigated. Insights into the effects of key microstructural features and dominant plastic deformation mechanisms influencing the measured relative activity of slip systems in SAC305 are obtained from a combination of optical microscopy, orientation imaging microscopy (OIM), slip plane trace analysis and crystal plasticity finite element (CPFE) modeling. Package level SAC305 specimens were subjected to shear deformation in sequential steps and characterized using optical microscopy and OIM to identify the activity of slip systems. X-ray micro Laue diffraction and high energy monochromatic X-ray beam were employed to characterize the joint scale tensile samples to provide necessary information to be able to compare and validate the CPFE model. A CPFE model was developed that can account for relative ease of activating slip systems in SAC305 solder based upon the statistical estimation based on correlation between the critical resolved shear stress and the probability of activating various slip systems. The results from simulations show that the CPFE model developed using the statistical analysis of activity of slip system not only can satisfy the requirements associated with kinematic of plastic deformation in crystal coordinate systems (activity of slip systems) and global coordinate system (shape changes

Identification of Plasmodium falciparum Translation Initiation eIF2β Subunit: Direct Interaction with Protein Phosphatase Type 1

Czech Academy of Sciences Publication Activity Database

Tellier, G.; Lenne, A.; Cailliau-Maggio, K.; Cabezas-Cruz, A.; Valdés, James J.; Martoriati, A.; Aliouat, El M.; Gosset, P.; Delaire, B.; Fréville, A.; Pierrot, C.; Khalife, J.

2016-01-01

Roč. 7, MAY 26 (2016), č. článku 777. ISSN 1664-302X Institutional support: RVO:60077344 Keywords : Plasmodium falciparum * Protein Phosphatase type1 * eIF2b * protein-protein interaction * translation complex Subject RIV: EE - Microbiology, Virology Impact factor: 4.076, year: 2016

Induction of rat yolk sac carcinomas with consistent pattern of laminin, entactin, and type IV collagen biosynthesis

DEFF Research Database (Denmark)

Wewer, U

1984-01-01

Twenty-four yolk sac carcinomas in Lewis rats were experimentally induced by puncturing the pregnant uterine wall with a hypodermic needle at day 9-13 of gestation. Morphologically, the tumours were composed of parietal- and visceral yolk sac carcinoma and to a less degree of trophoblastic giant...

Discovery and study of novel protein tyrosine phosphatase 1B inhibitors

Science.gov (United States)

Zhang, Qian; Chen, Xi; Feng, Changgen

2017-10-01

Protein tyrosine phosphatase 1B (PTP1B) is considered to be a target for therapy of type II diabetes and obesity. So it is of great significance to take advantage of a computer aided drug design protocol involving the structured-based virtual screening with docking simulations for fast searching small molecule PTP1B inhibitors. Based on optimized complex structure of PTP1B bound with specific inhibitor of IX1, structured-based virtual screening against a library of natural products containing 35308 molecules, which was constructed based on Traditional Chinese Medicine database@ Taiwan (TCM database@ Taiwan), was conducted to determine the occurrence of PTP1B inhibitors using the Lubbock module and CDOCKER module from Discovery Studio 3.1 software package. The results were further filtered by predictive ADME simulation and predictive toxic simulation. As a result, 2 good drug-like molecules, namely para-benzoquinone compound 1 and Clavepictine analogue 2 were identified ultimately with the dock score of original inhibitor (IX1) and the receptor as a threshold. Binding model analyses revealed that these two candidate compounds have good interactions with PTP1B. The PTP1B inhibitory activity of compound 2 hasn't been reported before. The optimized compound 2 has higher scores and deserves further study.

Distal Regeneration Involves the Age Dependent Activity of Branchial Sac Stem Cells in the Ascidian Ciona intestinalis.

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Jeffery, William R

2015-02-01

Tunicates have high capacities for regeneration but the underlying mechanisms and their relationship to life cycle progression are not well understood. Here we investigate the regeneration of distal structures in the ascidian tunicate Ciona intestinalis . Analysis of regenerative potential along the proximal-distal body axis indicated that distal organs, such as the siphons, their pigmented sensory organs, and the neural complex, could only be replaced from body fragments containing the branchial sac. Distal regeneration involves the formation of a blastema composed of cells that undergo cell proliferation prior to differentiation and cells that differentiate without cell proliferation. Both cell types originate in the branchial sac and appear in the blastema at different times after distal injury. Whereas the branchial sac stem cells are present in young animals, they are depleted in old animals that have lost their regeneration capacity. Thus Ciona adults contain a population of age-related stem cells located in the branchial sac that are a source of precursors for distal body regeneration.

The Student Actions Coding Sheet (SACS): An instrument for illuminating the shifts toward student-centered science classrooms

Science.gov (United States)

Erdogan, Ibrahim; Campbell, Todd; Hashidah Abd-Hamid, Nor

2011-07-01

This study describes the development of an instrument to investigate the extent to which student-centered actions are occurring in science classrooms. The instrument was developed through the following five stages: (1) student action identification, (2) use of both national and international content experts to establish content validity, (3) refinement of the item pool based on reviewer comments, (4) pilot testing of the instrument, and (5) statistical reliability and item analysis leading to additional refinement and finalization of the instrument. In the field test, the instrument consisted of 26 items separated into four categories originally derived from student-centered instruction literature and used by the authors to sort student actions in previous research. The SACS was administered across 22 Grade 6-8 classrooms by 22 groups of observers, with a total of 67 SACS ratings completed. The finalized instrument was found to be internally consistent, with acceptable estimates from inter-rater intraclass correlation reliability coefficients at the p Observation Protocol. Based on the analyses completed, the SACS appears to be a useful instrument for inclusion in comprehensive assessment packages for illuminating the extent to which student-centered actions are occurring in science classrooms.

The rat subcutaneous air sac model. A new and simple method for in vivo screening of antiangiogenesis

International Nuclear Information System (INIS)

Lichtenberg, J.; Abildgaard Hansen, C.; Skak-Nielsen, T.; Bay, C.; Thing Mortensen, J.; Binderup, L.

1997-01-01

An experimental rat model, the Subcutaneous Air Sac (SAS) model, was developed to provide an animal model in which neo-vascularisation can be easily assessed in situ and quantified using a radiolabelled plasma marker. The SAS model was designed to replace a previous model where neo-vascularisation was induced by chemical injury of rat or rabbit cornea or by implantation of tumour cells intracorneally, a methodology which is believed to cause severe pain to the animals. In the SAS model the air sac replaces the cornea as a transparent avascular substratum in which vascularisation can be observed. The air sac is induced by injection of air subcutaneously on the back of the animal. After 8 to 10 days a sufficient air sac has been established. The animal is anaesthesized and by a minor operation the cellulose sponge is implanted upon the air sac under the skin. The vaso-proliferative effect of the cellulose sponge caused formation of new vessels which are macroscopically visible 10 days after implantation. The ability of the in vivo SAS model to show an anti-angiogenic effect of a systemically applied test compound was investigated using the fumagilline analogue TNP-470 (o-chloro-acetylcarbomoyl-fumagillol) as a positive control at dose levels of 0, 1, 2.5, 5 and 10 mg/kg/day given subcutaneously for 10 days. The neo-angio genesis was scored both in situ using a subjective point system and by measuring the 125 I-activity of the implant and the membrane after an intravenous injection of 125 I-labelled antibodies. The neo-angio genesis was reduced by approximately 45-50% in animals treated with 5 or 10 mg/kg/day of TNP-470 compared to animals treated with the vehicle. The animals treated with 10 mg/kg/day TNP-470 showed signs of toxicity. The SAS model is considered highly relevant for in vivo testing of potential anti-angiogenci drugs on humane grounds. The high reproducibility, the low cost and the technical simplicity of the method makes it attractive. (au)

[Kinetic study on inhibition effects of dansyl-L-phenylalanine and L-phenylalanine on calf intestinal alkaline phosphatase].

Science.gov (United States)

Li, Li-Na; Wu, Yu-Qing; Buchet, René

2009-10-01

To evaluate the inhibition effect of dansyl-L-phenylalanine on calf intestinal alkaline phosphatase (CIAP), UV-Vis spectrophotometric method was employed. It was found that dansyl-L-phenylalanine can selectively inhibit CIAP. The kinetic inhibition processes of dansyl-L-phenylalanine and L-phenylalanine were comparatively studied. The authors' finding elucidates that at the optimized alkaline pH of alkaline phosphatase (pH 10.4) and 37 degrees C, dansyl-L-phenylalanine can inhibit alkaline phosphatase activity of CIAP efficiently and specifically, similar as L-phenylalanine. Both inhibition types were uncompetitive inhibition resulting from the double reciprocal curve fitting of upsilon versus substrate concentrations, and the inhibition constants Ki of both inhibitors were determined to be 2.3 and 1.1 mmol L(-1) respectively, both of which were at millimolar level. The investigation of the inhibition effect of dansyl modified L-phenylalanine on calf intestinal alkaline phosphatase not only helped get insight into the detailed inhibition mechanism of L-phenylalanine on tissue specific alkaline phosphatase, such as in the case of intestinal alkaline phosphatase, but also provided the possibility to employ fluorescence spectroscopy by labeling the specific inhibitors of alkaline phosphatase with chromophoric groups.

Bone histological correlates for air sacs and their implications for understanding the origin of the dinosaurian respiratory system.

Science.gov (United States)

Lambertz, Markus; Bertozzo, Filippo; Sander, P Martin

2018-01-01

Air sacs are an important component of the avian respiratory system, and corresponding structures also were crucial for the evolution of sauropod dinosaur gigantism. Inferring the presence of air sacs in fossils so far is restricted to bones preserving internal pneumatic cavities and foramina as osteological correlates. We here present bone histological correlates for air sacs as a new potential identification tool for these elements of the respiratory system. The analysis of several avian and non-avian dinosaur samples revealed delicate fibres in secondary trabecular and secondary endosteal bone that in the former case (birds) is known or in the latter (non-avian dinosaurs) assumed to have been in contact with air sacs, respectively. The bone histology of this 'pneumosteal tissue' is markedly different from those regions where muscles attached presenting classical Sharpey's fibres. The pneumatized bones of several non-dinosaurian taxa do not exhibit the characteristics of this 'pneumosteum'. Our new histology-based approach thus can be instrumental in reconstructing the origin of air sacs among dinosaurs and hence for our understanding of this remarkable evolutionary novelty of the respiratory system. © 2018 The Author(s).

On the origin of avian air sacs.

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Farmer, C G

2006-11-01

For many vertebrates the lung is the largest and lightest organ in the body cavity and for these reasons can greatly affect an organism's shape, density, and its distribution of mass; characters that are important to locomotion. In this paper non-respiratory functions of the lung are considered along with data on the respiratory capacities and gas exchange abilities of birds and crocodilians to infer the evolutionary history of the respiratory systems of dinosaurs, including birds. From a quadrupedal ancestry theropod dinosaurs evolved a bipedal posture. Bipedalism is an impressive balancing act, especially for tall animals with massive heads. During this transition selection for good balance and agility may have helped shape pulmonary morphology. Respiratory adaptations arising for bipedalism are suggested to include a reduction in costal ventilation and the use of cuirassal ventilation with a caudad expansion of the lung into the dorsal abdominal cavity. The evolution of volant animals from bipeds required yet again a major reorganization in body form. With this transition avian air sacs may have been favored because they enhanced balance and agility in flight. Finally, I propose that these hypotheses can be tested by examining the importance of the air sacs to balance and agility in extant animals and that these data will enhance our understanding of the evolution of the respiratory system in archosaurs.

MR imaging of the lumbar disk herniation : relationship between the direction of herniated disc and pressure effect on nerve root and dural sac

International Nuclear Information System (INIS)

Cha, B. H.; Shon, M. Y.; Kim, K. W.; Lim, M. A.; Kwon, K. R; Kim, S. S.

1996-01-01

To evaluate the relationship between the direction of herniated disc and pressure effect on nerve root and dural sac, as seen on MRI. We retrospectively reviewed lumbar spine MR images of 122 cases of lumbar disk herniation 75 patients MRI findings were analyzed with regard to the relationship between the direction of the herniated disc and pressure effect on nerve root and dural sac. Pressure effect on nerve root and dural sac was arbitrarily divided into three types. Type I was defined as zero or minimal compression of nerve roots or thecal sac by the herniated disc ; type II was defined as mild to moderate compression, while III was defined as severe compression or displacement of nerve roots and/or thecal sac. Of the 122 cases seen in these 75 patients, 97(80%) were observed at L4-5 and L5-S1. The central type(71cases ; 58%) was more frequently observed than the posterolateral type(48cases ; 40%) or lateral type(3cases ; 2%). The totals of types I, II, and III were 44(36%), 43(35%) and 35 cases(29%), respectively. Seventy-seven %(34/44) of type I and 65%(28/43) of type II were of the central type but for type III, the corresponding figure was only 26%(9/35). On MR imaging, most of lumbar disk herniations were observed at L4-5 and L5-S1, with a predominance of the central type rather than the posterolateral one. Most of the central types were either type I or type II

Elevated serum tartrate-resistant acid phosphatase isoform 5a levels in metabolic syndrome.

Science.gov (United States)

Huang, Yi-Jhih; Huang, Tsai-Wang; Chao, Tsu-Yi; Sun, Yu-Shan; Chen, Shyi-Jou; Chu, Der-Ming; Chen, Wei-Liang; Wu, Li-Wei

2017-09-29

Tartrate-resistant phosphatase isoform 5a is expressed in tumor-associated macrophages and is a biomarker of chronic inflammation. Herein, we correlated serum tartrate-resistant phosphatase isoform 5a levels with metabolic syndrome status and made comparisons with traditional markers of inflammation, including c-reactive protein and interleukin-6. One hundred healthy volunteers were randomly selected, and cut-off points for metabolic syndrome related inflammatory biomarkers were determined using receiver operating characteristic curves. Linear and logistic regression models were subsequently used to correlate inflammatory markers with the risk of metabolic syndrome. Twenty-two participants met the criteria for metabolic syndrome, and serum tartrate-resistant phosphatase isoform 5a levels of >5.8 μg/L were associated with metabolic syndrome (c-statistics, 0.730; p = 0.001; 95% confidence interval, 0.618-0.842). In addition, 1 μg/L increases in tartrate-resistant phosphatase isoform 5a levels were indicative of a 1.860 fold increase in the risk of metabolic syndrome (p = 0.012). Elevated serum tartrate-resistant phosphatase isoform 5a levels are associated with the risk of metabolic syndrome, with a cut-off level of 5.8 μg/L.

Protein tyrosine phosphatase SAP-1 protects against colitis through regulation of CEACAM20 in the intestinal epithelium.

Science.gov (United States)

Murata, Yoji; Kotani, Takenori; Supriatna, Yana; Kitamura, Yasuaki; Imada, Shinya; Kawahara, Kohichi; Nishio, Miki; Daniwijaya, Edwin Widyanto; Sadakata, Hisanobu; Kusakari, Shinya; Mori, Munemasa; Kanazawa, Yoshitake; Saito, Yasuyuki; Okawa, Katsuya; Takeda-Morishita, Mariko; Okazawa, Hideki; Ohnishi, Hiroshi; Azuma, Takeshi; Suzuki, Akira; Matozaki, Takashi

2015-08-04

Intestinal epithelial cells contribute to regulation of intestinal immunity in mammals, but the detailed molecular mechanisms of such regulation have remained largely unknown. Stomach-cancer-associated protein tyrosine phosphatase 1 (SAP-1, also known as PTPRH) is a receptor-type protein tyrosine phosphatase that is localized specifically at microvilli of the brush border in gastrointestinal epithelial cells. Here we show that SAP-1 ablation in interleukin (IL)-10-deficient mice, a model of inflammatory bowel disease, resulted in a marked increase in the severity of colitis in association with up-regulation of mRNAs for various cytokines and chemokines in the colon. Tyrosine phosphorylation of carcinoembryonic antigen-related cell adhesion molecule (CEACAM) 20, an intestinal microvillus-specific transmembrane protein of the Ig superfamily, was greatly increased in the intestinal epithelium of the SAP-1-deficient animals, suggesting that this protein is a substrate for SAP-1. Tyrosine phosphorylation of CEACAM20 by the protein tyrosine kinase c-Src and the consequent association of CEACAM20 with spleen tyrosine kinase (Syk) promoted the production of IL-8 in cultured cells through the activation of nuclear factor-κB (NF-κB). In addition, SAP-1 and CEACAM20 were found to form a complex through interaction of their ectodomains. SAP-1 and CEACAM20 thus constitute a regulatory system through which the intestinal epithelium contributes to intestinal immunity.

MRI of cul-de-sac endometriosis

International Nuclear Information System (INIS)

Balestrini, Maria A.; Martin, Eduardo; Gomez Sanetta, Santiago; De Lucas, Federico; Bruno, Claudio; Sanchez Marull, Ricardo; Villamayor, Irene

2000-01-01

The endometriosis is a gynecological disorder characterized by the presence of ectopic functioning endometrial tissue. According to different studies, the incidence of endometriosis in fertile women oscillates between 10% and 15%. There are many theories (Sampson or menstrual blood transport, coelomic methaplasia, lymphatic dissemination, blood, etc.) that take part in the ethiopatogenic explanation of the disease. The findings obtained by excretory urography, computed tomography (CT), magnetic resonance imaging (MRI), cytology and histology in a 31 years old patient with cul-de-sac endometriosis is presented. MRI was the imaging method of choice for diagnosis and follow-up after treatment of this condition. (author)

The protein histidine phosphatase LHPP is a tumour suppressor.

Science.gov (United States)

Hindupur, Sravanth K; Colombi, Marco; Fuhs, Stephen R; Matter, Matthias S; Guri, Yakir; Adam, Kevin; Cornu, Marion; Piscuoglio, Salvatore; Ng, Charlotte K Y; Betz, Charles; Liko, Dritan; Quagliata, Luca; Moes, Suzette; Jenoe, Paul; Terracciano, Luigi M; Heim, Markus H; Hunter, Tony; Hall, Michael N

2018-03-29

Histidine phosphorylation, the so-called hidden phosphoproteome, is a poorly characterized post-translational modification of proteins. Here we describe a role of histidine phosphorylation in tumorigenesis. Proteomic analysis of 12 tumours from an mTOR-driven hepatocellular carcinoma mouse model revealed that NME1 and NME2, the only known mammalian histidine kinases, were upregulated. Conversely, expression of the putative histidine phosphatase LHPP was downregulated specifically in the tumours. We demonstrate that LHPP is indeed a protein histidine phosphatase. Consistent with these observations, global histidine phosphorylation was significantly upregulated in the liver tumours. Sustained, hepatic expression of LHPP in the hepatocellular carcinoma mouse model reduced tumour burden and prevented the loss of liver function. Finally, in patients with hepatocellular carcinoma, low expression of LHPP correlated with increased tumour severity and reduced overall survival. Thus, LHPP is a protein histidine phosphatase and tumour suppressor, suggesting that deregulated histidine phosphorylation is oncogenic.

Knockout mice reveal a role for protein tyrosine phosphatase H1 in cognition

Directory of Open Access Journals (Sweden)

Ardizzone Michele

2008-08-01

Full Text Available Abstract Background The present study has investigated the protein tyrosine phosphatase H1 (PTPH1 expression pattern in mouse brain and its impact on CNS functions. Methods We have previously described a PTPH1-KO mouse, generated by replacing the PTP catalytic and the PDZ domain with a LacZ neomycin cassette. PTPH1 expression pattern was evaluated by LacZ staining in the brain and PTPH1-KO and WT mice (n = 10 per gender per genotype were also behaviorally tested for CNS functions. Results In CNS, PTPH1 is expressed during development and in adulthood and mainly localized in hippocampus, thalamus, cortex and cerebellum neurons. The behavioral tests performed on the PTPH1-KO mice showed an impact on working memory in male mice and an impaired learning performance at rotarod in females. Conclusion These results demonstrate for the first time a neuronal expression of PTPH1 and its functionality at the level of cognition.

Novel HIV-1 knockdown targets identified by an enriched kinases/phosphatases shRNA library using a long-term iterative screen in Jurkat T-cells.

Directory of Open Access Journals (Sweden)

Sylvie Rato

2010-02-01

Full Text Available HIV-1 is a complex retrovirus that uses host machinery to promote its replication. Understanding cellular proteins involved in the multistep process of HIV-1 infection may result in the discovery of more adapted and effective therapeutic targets. Kinases and phosphatases are a druggable class of proteins critically involved in regulation of signal pathways of eukaryotic cells. Here, we focused on the discovery of kinases and phosphatases that are essential for HIV-1 replication but dispensable for cell viability. We performed an iterative screen in Jurkat T-cells with a short-hairpin-RNA (shRNA library highly enriched for human kinases and phosphatases. We identified 14 new proteins essential for HIV-1 replication that do not affect cell viability. These proteins are described to be involved in MAPK, JNK and ERK pathways, vesicular traffic and DNA repair. Moreover, we show that the proteins under study are important in an early step of HIV-1 infection before viral integration, whereas some of them affect viral transcription/translation. This study brings new insights for the complex interplay of HIV-1/host cell and opens new possibilities for antiviral strategies.

Phosphate-solubility and phosphatase activity in Gangetic alluvial soil as influenced by organophosphate insecticide residues.

Science.gov (United States)

Majumder, Shyam Prasad; Das, Amal Chandra

2016-04-01

An experiment was conducted under laboratory conditions to investigate the effect of four organophosphate insecticides, viz. monocrotophos, profenophos, quinalphos and triazophos at their field application rates (0.75, 1.0, 0.5 and 0.6 kg a.i.ha(-1), respectively), on the growth and activities of phosphate solubilizing microorganisms in relation to availability of insoluble phosphates in the Gangetic alluvial soil of West Bengal, India. The proliferation of phosphate solubilizing microorganisms was highly induced with profenophos (38.3%), while monocrotophos exerted maximum stimulation (20.8%) towards the solubility of insoluble phosphates in soil. The phosphatase activities of the soil (both acid phosphatase and alkaline phosphatase) were significantly increased due to the incorporation of the insecticides in general, and the augmentation was more pronounced with quinalphos (43.1%) followed by profenophos (27.6%) for acid phosphatase, and with monocrotophos (25.2%) followed by profenophos (16.1%) for alkaline phosphatase activity in soil. The total phosphorus was highly retained by triazophos (19.9%) followed by monocrotophos (16.5%), while incorporation of triazophos and quinalphos manifested greater availability of water soluble phosphorus in soil. Copyright © 2015 Elsevier Inc. All rights reserved.

Co-ordinate regulation of growth factor receptors and lipid phosphate phosphatase-1 controls cell activation by exogenous lysophosphatidate.

Science.gov (United States)

Pilquil, C; Ling, Z C; Singh, I; Buri, K; Zhang, Q X; Brindley, D N

2001-11-01

The serum-derived lipid growth factors, lysophosphatidate (LPA) and sphingosine 1-phosphate (S1P), activate cells selectively through different members of a family of endothelial differentiation gene (EDG) receptors. Activation of EDG receptors by LPA and S1P provides a variety of signalling cascades depending upon the G-protein coupling of the different EDG receptors. This leads to chemotactic and mitogenic responses, which are important in wound healing. For example, LPA stimulates fibroblast division and S1P stimulates the chemotaxis and division of endothelial cells leading to angiogenesis. Counteracting these effects of LPA and S1P, are the actions of lipid phosphate phosphatases (LPP, or phosphatidate phosphohydrolases, Type 2). The isoform LPP-1 is expressed in the plasma membrane with its active site outside the cell. This enzyme is responsible for 'ecto-phosphatase' activity leading to the degradation of exogenous lipid phosphate mediators, particularly LPA. Expression of LPP-1 decreases cell activation by exogenous LPA. The mechanism for this is controversial and several mechanisms have been proposed. Evidence will be presented that the LPPs cross-talk with EDG and other growth factor receptors, thus, regulating the responses of the cells to lipid phosphate mediators of signal transduction.

Toward the identification of a reliable 3D-QSAR model for the protein tyrosine phosphatase 1B inhibitors

Science.gov (United States)

Wang, Fangfang; Zhou, Bo

2018-04-01

Protein tyrosine phosphatase 1B (PTP1B) is an intracellular non-receptor phosphatase that is implicated in signal transduction of insulin and leptin pathways, thus PTP1B is considered as potential target for treating type II diabetes and obesity. The present article is an attempt to formulate the three-dimensional quantitative structure-activity relationship (3D-QSAR) modeling of a series of compounds possessing PTP1B inhibitory activities using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) techniques. The optimum template ligand-based models are statistically significant with great CoMFA (R2cv = 0.600, R2pred = 0.6760) and CoMSIA (R2cv = 0.624, R2pred = 0.8068) values. Molecular docking was employed to elucidate the inhibitory mechanisms of this series of compounds against PTP1B. In addition, the CoMFA and CoMSIA field contour maps agree well with the structural characteristics of the binding pocket of PTP1B active site. The knowledge of structure-activity relationship and ligand-receptor interactions from 3D-QSAR model and molecular docking will be useful for better understanding the mechanism of ligand-receptor interaction and facilitating development of novel compounds as potent PTP1B inhibitors.

Low baseline and subsequent higher aortic abdominal aneurysm FDG uptake are associated with poor sac shrinkage post endovascular repair

Energy Technology Data Exchange (ETDEWEB)

Marie, Pierre-Yves [CHRU-Nancy, Universite de Lorraine, Nuclear Medecine and Nancyclotep Platform, Nancy (France); INSERM, University of Lorraine, UMR 1116, Nancy (France); CHRU-Nancy, Hopitaux de BRABOIS, Service de Medecine Nucleaire, Vandoeuvre (France); Plissonnier, Didier; Rouer, Martin [CHU-Rouen, Department of Vascular Surgery, Rouen (France); Bravetti, Stephanie [CHRU-Nancy, Universite de Lorraine, Department of Radiology, Nancy (France); Coscas, Raphael [Hopital Ambroise Pare, APHP, Chirurgie Vasculaire, Boulogne-Billancourt (France); Haulon, Stephan [CHU-Lille, Department of Vascular Surgery, Lille (France); Mandry, Damien [CHRU-Nancy, Universite de Lorraine, Department of Radiology, Nancy (France); INSERM, University of Lorraine, UMR 947, Nancy (France); Alsac, Jean-Marc [grid.414093.b, APHP, HEGP, Department of Vascular Surgery, Paris (France); Malikov, Serguei; Settembre, Nicla [CHRU-Nancy, Universite de Lorraine, Vascular Surgery, Nancy (France); Goueffic, Yann [CHU-Nantes, Department of Vascular Surgery, Nantes (France); Morel, Olivier [CHU-Besancon, Department of Nuclear Medecine, Besancon (France); Roch, Veronique [CHRU-Nancy, Universite de Lorraine, Nuclear Medecine and Nancyclotep Platform, Nancy (France); Micard, Emilien [INSERM, University of Lorraine, UMR 947, Nancy (France); INSERM, CHRU-Nancy, Universite de Lorraine, CIC-1433, FCRIN INI-CRCT, Nancy (France); Lamiral, Zohra [INSERM, CHRU-Nancy, Universite de Lorraine, CIC-1433, FCRIN INI-CRCT, Nancy (France); Michel, Jean-Baptiste [INSERM, Bichat, UMR 698, Paris (France); Rossignol, Patrick [INSERM, University of Lorraine, UMR 1116, Nancy (France); INSERM, CHRU-Nancy, Universite de Lorraine, CIC-1433, FCRIN INI-CRCT, Nancy (France)

2018-04-15

The growth phases of medically treated abdominal aortic aneurysms (AAA) are frequently associated with an {sup 18}F-fluorodesoxyglucose positron emission tomography (FDG-PET) pattern involving low baseline and subsequent higher FDG uptake. However, the FDG-PET patterns associated with the endovascular aneurysm repair (EVAR) of larger AAA are presently unknown. This study aimed to investigate the relationship between serial AAA FDG uptake measurements, obtained before EVAR and 1 and 6 months post-intervention and subsequent sac shrinkage at 6 months, a well-recognized indicator of successful repair. Thirty-three AAA patients referred for EVAR (maximal diameter: 55.4 ± 6.0 mm, total volume: 205.7 ± 63.0 mL) underwent FDG-PET/computed tomography (CT) before EVAR and at 1 and 6 months thereafter, with the monitoring of AAA volume and of a maximal standardized FDG uptake [SUVmax] averaged between the axial slices encompassing the AAA. Sac shrinkage was highly variable and could be stratified into three terciles: a first tercile in which shrinkage was absent or very limited (0-29 mL) and a third tercile with pronounced shrinkage (56-165 mL). SUVmax values were relatively low at baseline in the 1st tercile (SUVmax: 1.69 ± 0.33), but markedly increased at 6 months (2.42 ± 0.69, p = 0.02 vs. baseline). These SUV max values were by contrast much higher at baseline in the 3rd tercile (SUVmax: 2.53 ± 0.83 p = 0.009 vs. 1st tercile) and stable at 6 months (2.49 ± 0.80), while intermediate results were documented in the 2nd tercile. Lastly, the amount of sac shrinkage, expressed in absolute values or in percentages of baseline AAA volumes, was positively correlated with baseline SUVmax (p = 0.001 for both). A low pre-EVAR FDG uptake and increased AAA FDG uptake at 6 months are associated with reduced sac shrinkage. This sequential FDG-PET pattern is similar to that already shown to accompany growth phases of medically treated AAA. (orig.)

Low baseline and subsequent higher aortic abdominal aneurysm FDG uptake are associated with poor sac shrinkage post endovascular repair

International Nuclear Information System (INIS)

Marie, Pierre-Yves; Plissonnier, Didier; Rouer, Martin; Bravetti, Stephanie; Coscas, Raphael; Haulon, Stephan; Mandry, Damien; Alsac, Jean-Marc; Malikov, Serguei; Settembre, Nicla; Goueffic, Yann; Morel, Olivier; Roch, Veronique; Micard, Emilien; Lamiral, Zohra; Michel, Jean-Baptiste; Rossignol, Patrick

2018-01-01

The growth phases of medically treated abdominal aortic aneurysms (AAA) are frequently associated with an 18 F-fluorodesoxyglucose positron emission tomography (FDG-PET) pattern involving low baseline and subsequent higher FDG uptake. However, the FDG-PET patterns associated with the endovascular aneurysm repair (EVAR) of larger AAA are presently unknown. This study aimed to investigate the relationship between serial AAA FDG uptake measurements, obtained before EVAR and 1 and 6 months post-intervention and subsequent sac shrinkage at 6 months, a well-recognized indicator of successful repair. Thirty-three AAA patients referred for EVAR (maximal diameter: 55.4 ± 6.0 mm, total volume: 205.7 ± 63.0 mL) underwent FDG-PET/computed tomography (CT) before EVAR and at 1 and 6 months thereafter, with the monitoring of AAA volume and of a maximal standardized FDG uptake [SUVmax] averaged between the axial slices encompassing the AAA. Sac shrinkage was highly variable and could be stratified into three terciles: a first tercile in which shrinkage was absent or very limited (0-29 mL) and a third tercile with pronounced shrinkage (56-165 mL). SUVmax values were relatively low at baseline in the 1st tercile (SUVmax: 1.69 ± 0.33), but markedly increased at 6 months (2.42 ± 0.69, p = 0.02 vs. baseline). These SUV max values were by contrast much higher at baseline in the 3rd tercile (SUVmax: 2.53 ± 0.83 p = 0.009 vs. 1st tercile) and stable at 6 months (2.49 ± 0.80), while intermediate results were documented in the 2nd tercile. Lastly, the amount of sac shrinkage, expressed in absolute values or in percentages of baseline AAA volumes, was positively correlated with baseline SUVmax (p = 0.001 for both). A low pre-EVAR FDG uptake and increased AAA FDG uptake at 6 months are associated with reduced sac shrinkage. This sequential FDG-PET pattern is similar to that already shown to accompany growth phases of medically treated AAA. (orig.)

Phosphatase-regulated recruitment of the spindle- and kinetochore-associated (Ska complex to kinetochores

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Sushama Sivakumar

2017-11-01

Full Text Available Kinetochores move chromosomes on dynamic spindle microtubules and regulate signaling of the spindle checkpoint. The spindle- and kinetochore-associated (Ska complex, a hexamer composed of two copies of Ska1, Ska2 and Ska3, has been implicated in both roles. Phosphorylation of kinetochore components by the well-studied mitotic kinases Cdk1, Aurora B, Plk1, Mps1, and Bub1 regulate chromosome movement and checkpoint signaling. Roles for the opposing phosphatases are more poorly defined. Recently, we showed that the C terminus of Ska1 recruits protein phosphatase 1 (PP1 to kinetochores. Here we show that PP1 and protein phosphatase 2A (PP2A both promote accumulation of Ska at kinetochores. Depletion of PP1 or PP2A by siRNA reduces Ska binding at kinetochores, impairs alignment of chromosomes to the spindle midplane, and causes metaphase delay or arrest, phenotypes that are also seen after depletion of Ska. Artificial tethering of PP1 to the outer kinetochore protein Nuf2 promotes Ska recruitment to kinetochores, and it reduces but does not fully rescue chromosome alignment and metaphase arrest defects seen after Ska depletion. We propose that Ska has multiple functions in promoting mitotic progression and that kinetochore-associated phosphatases function in a positive feedback cycle to reinforce Ska complex accumulation at kinetochores.

Penostatin Derivatives, a Novel Kind of Protein Phosphatase 1B Inhibitors Isolated from Solid Cultures of the Entomogenous Fungus Isaria tenuipes

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Yu-Peng Chen

2014-01-01

Full Text Available Protein tyrosine phosphatase 1B (PTP1B is implicated as a negative regulator of insulin receptor (IR signaling and a potential drug target for the treatment of type II diabetes and other associated metabolic syndromes. Therefore, small molecular inhibitors of PTP1B can be considered as an attractive approach for the design of new therapeutic agents of type II diabetes diseases. In a continuing search for new protein phosphatase inhibitors from fungi, we have isolated a new compound, named penostatin J (1, together with three known ones, penostatin C (2, penostatin A (3, and penostatin B (4, from cultures of the entomogenous fungus Isaria tenuipes. The structure of penostatin J (1 was elucidated by extensive spectroscopic analysis. We also demonstrate for the first time that penostatin derivatives exhibit the best PTP1B inhibitory action. These findings suggest that penostatin derivatives are a potential novel kind of PTP1B inhibitors.

Comparison between Conventional OCDMA and Subcarrier Multiplexing SAC OCDMA System Based on Single Photodiode Detection

OpenAIRE

Ahmad N. A. A; Junita M. N; Aljunid Syed Alwi; Che Beson Mohd Rashidi; Endut Rosdisham

2017-01-01

This paper demonstrates the comparison between conventional OCDMA system and subcarrier multiplexing (SCM) SAC-OCDMA system by applying Recursive Combinatorial (RC) code based on single photodiode detection (SPD). SPD is used in the receiver part to reduce the effect of multiple access interference (MAI) which contributes as a dominant noise in incoherent SAC-OCDMA systems. From this analysis, the performance of SCM OCDMA network could be improved by using lower data rates and higher received...

A Giant Occipital Encephalocele in Neonate with Spontaneous Hemorrhage into the Encephalocele Sac: Surgical Management

OpenAIRE

Satyarthee, Guru Dutta; Moscote-Salazar, Luis Rafael; Escobar-Hernandez, Nidia; Aquino-Matus, Jose; Puac-Polanco, Paulo Cesar; Hoz, Samer S; Calderon-Miranda, Willem Guillermo

2017-01-01

The presence of giant occipital encephalocele represents a surgical challenge. However, preoperative magnetic resonance imaging with venography can help in delineating relation of venous sinus, content of the sac and help classify occipital encephalocele into infra-torcular and torcular depending on the relation with position of torcula. However, the presence of old hemorrhage into encephalocele sac is extremely rare and in the detailed PubMed search, the authors could find one such case, rep...

A phosphatase-independent gain-of-function mutation in PTEN triggers aberrant cell growth in astrocytes through an autocrine IGF-1 loop.

Science.gov (United States)

Fernández, S; Genis, L; Torres-Alemán, I

2014-08-07

Loss-of-function mutations in the phosphatase PTEN (phosphatase and tensin homolog deleted on chromosome10) contribute to aberrant cell growth in part through upregulation of the mitogenic IGF-1/PI3K/Akt pathway. In turn, this pathway exerts a homeostatic feedback over PTEN. Using mutagenesis analysis to explore a possible impact of this mutual control on astrocyte growth, we found that truncation of the C-terminal region of PTEN (Δ51) associates with a marked increase in NFκB activity, a transcription factor overactivated in astrocyte tumors. Whereas mutations of PTEN are considered to lead to a loss-of-function, PTENΔ51, a truncation that comprises a region frequently mutated in human gliomas, displayed a neomorphic (gain-of-function) activity that was independent of its phosphatase activity. This gain-of-function of PTENΔ51 includes stimulation of IGF-1 synthesis through protein kinase A activation of the IGF-1 promoter. Increased IGF-1 originates an autocrine loop that activates Akt and NFκB. Constitutive activation of NFκB in PTENΔ51-expressing astrocytes leads to aberrant cell growth; astrocytes expressing this mutant PTEN generate colonies in vitro and tumors in vivo. Mutations converting a tumor suppressor such as PTEN into a tumor promoter through a gain-of-function involving IGF-1 production may further our understanding of the role played by this growth factor in glioma growth and help us define druggable targets for personalized therapy.

Changes in endolymphatic hydrops visualized by magnetic resonance imaging after sac surgery.

Science.gov (United States)

Zhang, Yuan; Cui, Yong-Hua; Hu, Ying; Mao, Zhong-Yao; Wang, Qiu-Xia; Pan, Chu; Liu, Ai-Guo

2016-10-01

The purpose of the study was to observe changes in endolymphatic hydrops by using intratympanic injection of gadolinium and magnetic resonance imaging (MRI) before and after endolymphatic sac surgery in patients with unilateral Meniere's disease. Thirteen patients with unilateral Meniere's disease undergoing endolymphatic sac surgery were retrospectively and prospectively analyzed. Three-dimensional fluid-attenuated inversion recovery or three-dimensional real inversion recovery MRI was performed 24 h after an intratympanic injection of gadolinium to grade the presence of endolymphatic hydrops. Among the 13 patients with hydrops confirmed by preoperative MRI, vestibular hydrops had no significant change in all patients; cochlear hydrops became negative in 2 patients, and remained unchanged in the other 11 patients after surgery. Definite vertigo attacks were substantially controlled in one patient and completely controlled in 12 patients during a follow-up period of 8-34 months after surgery. The hearing levels were improved in 3 patients, remained unchanged in 7 patients, and decreased in 3 patients. In conclusion, endolymphatic sac surgery does not always alleviate endolymphatic hydrops in patients with Meniere's disease. Relief from vertigo cannot always be attributed to the remission of hydrops. A change in hearing levels cannot be explained by hydrops status alone.

Clearance of chlamydial elementary bodies from the conjunctival sac

International Nuclear Information System (INIS)

Taylor, H.R.; Velez, V.L.

1987-01-01

The rate of disappearance of inactivated Chlamydia trachomatis elementary body (EB) preparations from the conjunctival sac was studied in monkeys. Direct fluorescent antibody (DFA) cytology showed that the majority of EB had been cleared from the eye within 24 hr of the inoculation of 1 X 10(6) inactivated EB, although small numbers of EB could be detected for up to 144 hr. The rate of clearance in normal and ocular immune animals did not differ, and formalin-killed and UV-inactivated EBs disappeared at a comparable rate. These studies suggest that chlamydial EB are cleared relatively quickly from the eye and support the notion that EBs detected by DFA cytology indicate the presence of current infection

Catalytic Subunit 1 of Protein Phosphatase 2A Is a Subunit of the STRIPAK Complex and Governs Fungal Sexual Development.

Science.gov (United States)

Beier, Anna; Teichert, Ines; Krisp, Christoph; Wolters, Dirk A; Kück, Ulrich

2016-06-21

The generation of complex three-dimensional structures is a key developmental step for most eukaryotic organisms. The details of the molecular machinery controlling this step remain to be determined. An excellent model system to study this general process is the generation of three-dimensional fruiting bodies in filamentous fungi like Sordaria macrospora Fruiting body development is controlled by subunits of the highly conserved striatin-interacting phosphatase and kinase (STRIPAK) complex, which has been described in organisms ranging from yeasts to humans. The highly conserved heterotrimeric protein phosphatase PP2A is a subunit of STRIPAK. Here, catalytic subunit 1 of PP2A was functionally characterized. The Δpp2Ac1 strain is sterile, unable to undergo hyphal fusion, and devoid of ascogonial septation. Further, PP2Ac1, together with STRIPAK subunit PRO22, governs vegetative and stress-related growth. We revealed in vitro catalytic activity of wild-type PP2Ac1, and our in vivo analysis showed that inactive PP2Ac1 blocks the complementation of the sterile deletion strain. Tandem affinity purification, followed by mass spectrometry and yeast two-hybrid analysis, verified that PP2Ac1 is a subunit of STRIPAK. Further, these data indicate links between the STRIPAK complex and other developmental signaling pathways, implying the presence of a large interconnected signaling network that controls eukaryotic developmental processes. The insights gained in our study can be transferred to higher eukaryotes and will be important for understanding eukaryotic cellular development in general. The striatin-interacting phosphatase and kinase (STRIPAK) complex is highly conserved from yeasts to humans and is an important regulator of numerous eukaryotic developmental processes, such as cellular signaling and cell development. Although functional insights into the STRIPAK complex are accumulating, the detailed molecular mechanisms of single subunits are only partially understood

Gardenia jasminoides Encodes an Inhibitor-2 Protein for Protein Phosphatase Type 1

Science.gov (United States)

Gao, Lan; Li, Hao-Ming

2017-08-01

Protein phosphatase-1 (PP1) regulates diverse, essential cellular processes such as cell cycle progression, protein synthesis, muscle contraction, carbohydrate metabolism, transcription and neuronal signaling. Inhibitor-2 (I-2) can inhibit the activity of PP1 and has been found in diverse organisms. In this work, a Gardenia jasminoides fruit cDNA library was constructed, and the GjI-2 cDNA was isolated from the cDNA library by sequencing method. The GjI-2 cDNA contains a predicted 543 bp open reading frame that encodes 180 amino acids. The bioinformatics analysis suggested that the GjI-2 has conserved PP1c binding motif, and contains a conserved phosphorylation site, which is important in regulation of its activity. The three-dimensional model structure of GjI-2 was buite, its similar with the structure of I-2 from mouse. The results suggest that GjI-2 has relatively conserved RVxF, FxxR/KxR/K and HYNE motif, and these motifs are involved in interaction with PP1.

Phosphatase activity of Poa pratensis seeds. III. Effect of fluoride, citrate, urea and other substances on the activity of acid phosphatase Ia2 and Ia3

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Irena Lorenc-Kubis

2015-01-01

Full Text Available Effects of fluoride, citrate, urea and other substances on the activity of acid phosphatase a2 and a3 toward p-nitrophenylphosphate and phenylphosphate were investigated. Both enzymes were inhibited by fluoride, p-chloromercuribenzoate and oxalate. Fluoride inhibited acid phosphatase a2 noncorapetitively with p-mitrophenylphosphate, whereas acid phosphatase a3 showed inhibition of mixed type. Hydrolysis of phenylphosphate by both acid phosphatases was activated by citrate. Cytosine and uridine inhibited the activity of phosphatase a2 toward p-nitrophenylphosphate and phenylphosphate, but no effect was observed in case of acid phosphatase a3. After 30 min. incubation with 4 M urea both enzymes lost about 30% of activity.

Cardiac sodium channel Na(v)1.5 interacts with and is regulated by the protein tyrosine phosphatase PTPH1

DEFF Research Database (Denmark)

Jespersen, Thomas; Gavillet, Bruno; van Bemmelen, Miguel X

2006-01-01

In order to identify proteins interacting with the cardiac voltage-gated sodium channel Na(v)1.5, we used the last 66 amino acids of the C-terminus of the channel as bait to screen a human cardiac cDNA library. We identified the protein tyrosine phosphatase PTPH1 as an interacting protein. Pull......-down experiments confirmed the interaction, and indicated that it depends on the PDZ-domain binding motif of Na(v)1.5. Co-expression experiments in HEK293 cells showed that PTPH1 shifts the Na(v)1.5 availability relationship toward hyperpolarized potentials, whereas an inactive PTPH1 or the tyrosine kinase Fyn...... does the opposite. The results of this study suggest that tyrosine phosphorylation destabilizes the inactivated state of Na(v)1.5....

Contribution to the study of the reduction of sulfate by the yolk sac of the chicken embryo

International Nuclear Information System (INIS)

Bourgeois, Claude

1958-11-01

This academic reports addresses additional information obtained about the reduction of sulfate into sulphite by the yolk sac of a chicken embryo. Two important difficulties have been faced: the impossibility to isolate this reduction from reactions which immediately use the formed sulphite, and the impossibility to obtain an acellular preparation able to reduce the sulfate. Then, the problem of reduction of sulfate into sulphite by the yolk sac is associated with the problem of permeability of yolk sac cells to the studied substances. Thus, the author studied whether other animal species could provide a better material than the chicken embryo for this study of sulfate reduction. It appears that some vertebrate embryos present some evidence of sulphur metabolism similar to that of chicken embryo. However, this last one revealed to be the most favourable for the study. The author reports the study of the evolution of the reduction activity of the yolk sac sulfate with respect to the embryo age, and the effect of some metabolic inhibitors on this activity [fr

Distal regeneration involves the age dependent activity of branchial sac stem cells in the ascidian Ciona intestinalis

Science.gov (United States)

2014-01-01

Abstract Tunicates have high capacities for regeneration but the underlying mechanisms and their relationship to life cycle progression are not well understood. Here we investigate the regeneration of distal structures in the ascidian tunicate Ciona intestinalis. Analysis of regenerative potential along the proximal−distal body axis indicated that distal organs, such as the siphons, their pigmented sensory organs, and the neural complex, could only be replaced from body fragments containing the branchial sac. Distal regeneration involves the formation of a blastema composed of cells that undergo cell proliferation prior to differentiation and cells that differentiate without cell proliferation. Both cell types originate in the branchial sac and appear in the blastema at different times after distal injury. Whereas the branchial sac stem cells are present in young animals, they are depleted in old animals that have lost their regeneration capacity. Thus Ciona adults contain a population of age‐related stem cells located in the branchial sac that are a source of precursors for distal body regeneration. PMID:25893097

Characteristics of indomethacin-saccharin (IMC-SAC) co-crystals prepared by an anti-solvent crystallization process.

Science.gov (United States)

Chun, Nan-Hee; Wang, In-Chun; Lee, Min-Jeong; Jung, Yun-Taek; Lee, Sangkil; Kim, Woo-Sik; Choi, Guang J

2013-11-01

The creation of co-crystals of various insoluble drug substances has been extensively investigated as a promising approach to improve their pharmaceutical performance. In this study, co-crystal powders of indomethacin and saccharin (IMC-SAC) were prepared by an anti-solvent (water) addition and compared with co-crystals by evaporation method. No successful synthesis of a pharmaceutical co-crystal powder via an anti-solvent approach has been reported. Among solvents examined, methanol was practically the only one that resulted in the formation of highly pure IMC-SAC co-crystal powders by anti-solvent approach. The mechanism of a preferential formation of IMC-SAC co-crystal to IMC was explained with two aspects: phase solubility diagram and solution complexation concept. Accordingly, the anti-solvent approach can be considered as a competitive route for producing pharmaceutical co-crystal powders with acceptable properties. Copyright © 2013 Elsevier B.V. All rights reserved.

Phosphoinositides play differential roles in regulating phototropin1- and phototropin2-mediated chloroplast movements in Arabidopsis.

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Chhavi Aggarwal

Full Text Available Phototropins are UVA/blue-light receptors involved in controlling the light-dependent physiological responses which serve to optimize the photosynthetic activity of plants and promote growth. The phototropin-induced phosphoinositide (PI metabolism has been shown to be essential for stomatal opening and phototropism. However, the role of PIs in phototropin-induced chloroplast movements remains poorly understood. The aim of this work is to determine which PI species are involved in the control of chloroplast movements in Arabidopsis and the nature of their involvement. We present the effects of the inactivation of phospholipase C (PLC, PI3-kinase (PI3K and PI4-kinase (PI4K on chloroplast relocations in Arabidopsis. The inhibition of the phosphatidylinositol 4,5-bisphospahte [PI(4,5P2]-PLC pathway, using neomycin and U73122, suppressed the phot2-mediated chloroplast accumulation and avoidance responses, without affecting movement responses controlled by phot1. On the other hand, PI3K and PI4K activities are more restricted to phot1- and phot2-induced weak-light responses. The inactivation of PI3K and PI4K by wortmannin and LY294002 severely affected the weak blue-light-activated accumulation response but had little effect on the strong blue-light-activated avoidance response. The inhibitory effect observed with PI metabolism inhibitors is, at least partly, due to a disturbance in Ca(2+ ((c signaling. Using the transgenic aequorin system, we show that the application of these inhibitors suppresses the blue-light-induced transient Ca(2+ ((c rise. These results demonstrate the importance of PIs in chloroplast movements, with the PI(4,5P2-PLC pathway involved in phot2 signaling while PI3K and PI4K are required for the phot1- and phot2-induced accumulation response. Our results suggest that these PIs modulate cytosolic Ca(2+ signaling during movements.

Phosphoinositides play differential roles in regulating phototropin1- and phototropin2-mediated chloroplast movements in Arabidopsis.

Science.gov (United States)

Aggarwal, Chhavi; Labuz, Justyna; Gabryś, Halina

2013-01-01

Phototropins are UVA/blue-light receptors involved in controlling the light-dependent physiological responses which serve to optimize the photosynthetic activity of plants and promote growth. The phototropin-induced phosphoinositide (PI) metabolism has been shown to be essential for stomatal opening and phototropism. However, the role of PIs in phototropin-induced chloroplast movements remains poorly understood. The aim of this work is to determine which PI species are involved in the control of chloroplast movements in Arabidopsis and the nature of their involvement. We present the effects of the inactivation of phospholipase C (PLC), PI3-kinase (PI3K) and PI4-kinase (PI4K) on chloroplast relocations in Arabidopsis. The inhibition of the phosphatidylinositol 4,5-bisphospahte [PI(4,5)P2]-PLC pathway, using neomycin and U73122, suppressed the phot2-mediated chloroplast accumulation and avoidance responses, without affecting movement responses controlled by phot1. On the other hand, PI3K and PI4K activities are more restricted to phot1- and phot2-induced weak-light responses. The inactivation of PI3K and PI4K by wortmannin and LY294002 severely affected the weak blue-light-activated accumulation response but had little effect on the strong blue-light-activated avoidance response. The inhibitory effect observed with PI metabolism inhibitors is, at least partly, due to a disturbance in Ca(2+) ((c)) signaling. Using the transgenic aequorin system, we show that the application of these inhibitors suppresses the blue-light-induced transient Ca(2+) ((c)) rise. These results demonstrate the importance of PIs in chloroplast movements, with the PI(4,5)P2-PLC pathway involved in phot2 signaling while PI3K and PI4K are required for the phot1- and phot2-induced accumulation response. Our results suggest that these PIs modulate cytosolic Ca(2+) signaling during movements.

Lacrimal sac lymphoproliferative lesion: case report.

Science.gov (United States)

Coloma-González, I; Ruíz-García, L; Ceriotto, A; Corredor-Casas, S; Salcedo-Casillas, G

2015-03-01

The case is presented of a 51 year-old woman with a firm mass at the medial canthus of the right eye of five years onset. A low-grade lymphoproliferative lesion (reactive lymphoid hyperplasia) was diagnosed from an excisional biopsy Lacrimal sac tumors are rare, with a peak incidence in the fifth decade of life. The initial clinical features are epiphora and medial canthus swelling. As it mimics nasolacrimal duct obstruction, up to 40% of these tumors are misdiagnosed until undergoing surgery. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

Production, secretion, and stability of human secreted alkaline phosphatase in tobacco NT1 cell suspension cultures.

Science.gov (United States)

Becerra-Arteaga, Alejandro; Mason, Hugh S; Shuler, Michael L

2006-01-01

Tobacco NT1 cell suspension cultures secreting active human secreted alkaline phosphatase (SEAP) were generated for the first time as a model system to study recombinant protein production, secretion, and stability in plant cell cultures. The SEAP gene encodes a secreted form of the human placental alkaline phosphatase (PLAP). During batch culture, the highest level of active SEAP in the culture medium (0.4 U/mL, corresponding to approximately 27 mg/L) was observed at the end of the exponential growth phase. Although the level of active SEAP decreased during the stationary phase, the activity loss did not appear to be due to SEAP degradation (based on Western blots) but due to SEAP denaturation. The protein-stabilizing agents polyvinylpirrolidone (PVP) and bacitracin were added extracellularly to test for their ability to reduce the loss of SEAP activity during the stationary phase. Bacitracin (100 mg/L) was the most effective treatment at sustaining activity levels for up to 17 days post-subculture. Commercially available human placental alkaline phosphatase (PLAP) was used to probe the mechanism of SEAP deactivation. Experiments with PLAP in sterile and conditioned medium corroborated the denaturation of SEAP by factors generated by cell growth and not due to simple proteolysis. We also show for the first time that the factors promoting activity loss are heat labile at 95 degrees C but not at 70 degrees C, and they are not inactivated after a 5 day incubation period under normal culture conditions (27 degrees C). In addition, there were no significant changes in pH or redox potential when comparing sterile and cell-free conditioned medium during PLAP incubation, indicating that these factors were unimportant.

Genome wide identification of wheat and Brachypodium type one protein phosphatases and functional characterization of durum wheat TdPP1a.

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Mariem Bradai

Full Text Available Reversible phosphorylation is an essential mechanism regulating signal transduction during development and environmental stress responses. An important number of dephosphorylation events in the cell are catalyzed by type one protein phosphatases (PP1, which catalytic activity is driven by the binding of regulatory proteins that control their substrate specificity or subcellular localization. Plants harbor several PP1 isoforms accounting for large functional redundancies. While animal PP1s were reported to play relevant roles in controlling multiple cellular processes, plant orthologs remain poorly studied. To decipher the role of plant PP1s, we compared PP1 genes from three monocot species, Brachypodium, common wheat and rice at the genomic and transcriptomic levels. To gain more insight into the wheat PP1 proteins, we identified and characterized TdPP1a, the first wheat type one protein phosphatase from a Tunisian durum wheat variety Oum Rabiaa3. TdPP1a is highly conserved in sequence and structure when compared to mammalian, yeast and other plant PP1s. We demonstrate that TdPP1a is an active, metallo-dependent phosphatase in vitro and is able to interact with AtI2, a typical regulator of PP1 functions. Also, TdPP1a is capable to complement the heat stress sensitivity of the yeast mutant indicating that TdPP1a is functional also in vivo. Moreover, transient expression of TdPP1a::GFP in tobacco leaves revealed that it is ubiquitously distributed within the cell, with a strong accumulation in the nucleus. Finally, transcriptional analyses showed similar expression levels in roots and leaves of durum wheat seedlings. Interestingly, the expression in leaves is significantly induced following salinity stress, suggesting a potential role of TdPP1a in wheat salt stress response.

Modulation of Spc1 stress-activated protein kinase activity by methylglyoxal through inhibition of protein phosphatase in the fission yeast Schizosaccharomyces pombe

International Nuclear Information System (INIS)

Takatsume, Yoshifumi; Izawa, Shingo; Inoue, Yoshiharu

2007-01-01

Methylglyoxal, a ubiquitous metabolite derived from glycolysis has diverse physiological functions in yeast cells. Previously, we have reported that extracellularly added methylglyoxal activates Spc1, a stress-activated protein kinase (SAPK), in the fission yeast Schizosaccharomyces pombe [Y. Takatsume, S. Izawa, Y. Inoue, J. Biol. Chem. 281 (2006) 9086-9092]. Phosphorylation of Spc1 by treatment with methylglyoxal in S. pombe cells defective in glyoxalase I, an enzyme crucial for the metabolism of methylglyoxal, continues for a longer period than in wild-type cells. Here we show that methylglyoxal inhibits the activity of the protein phosphatase responsible for the dephosphorylation of Spc1 in vitro. In addition, we found that methylglyoxal inhibits human protein tyrosine phosphatase 1B (PTP1B) also. We propose a model for the regulation of the activity of the Spc1-SAPK signaling pathway by methylglyoxal in S. pombe

Optimization of extraction parameters of PTP1β (protein tyrosine phosphatase 1β), inhibitory polyphenols, and anthocyanins from Zea mays L. using response surface methodology (RSM).

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Hwang, Seung Hwan; Kwon, Shin Hwa; Wang, Zhiqiang; Kim, Tae Hyun; Kang, Young-Hee; Lee, Jae-Yong; Lim, Soon Sung

2016-08-26

Protein tyrosine phosphatase expressed in insulin-sensitive tissues (such as liver, muscle, and adipose tissue) has a key role in the regulation of insulin signaling and pathway activation, making protein tyrosine phosphatase a promising target for the treatment of type 2 diabetes mellitus and obesity and response surface methodology (RSM) is an effective statistical technique for optimizing complex processes using a multi-variant approach. In this study, Zea mays L. (Purple corn kernel, PCK) and its constituents were investigated for protein tyrosine phosphatase 1β (PTP1β) inhibitory activity including enzyme kinetic study and to improve total yields of anthocyanins and polyphenols, four extraction parameters, including temperature, time, solid-liquid ratio, and solvent volume, were optimized by RSM. Isolation of seven polyphenols and five anthocyanins was achieved by PTP1β assay. Among them, cyanidin-3-(6"malonylglucoside) and 3'-methoxyhirsutrin showed the highest PTP1β inhibition with IC50 values of 54.06 and 64.04 μM, respectively and 4.52 mg gallic acid equivalent/g (GAE/g) of total polyphenol content (TPC) and 43.02 mg cyanidin-3-glucoside equivalent/100 g (C3GE/100g) of total anthocyanin content (TAC) were extracted at 40 °C for 8 h with a 33 % solid-liquid ratio and a 1:15 solvent volume. Yields were similar to predictions of 4.58 mg GAE/g of TPC and 42.28 mg C3GE/100 g of TAC. These results indicated that PCK and 3'-methoxyhirsutrin and cyanidin-3-(6"malonylglucoside) might be active natural compounds and could be apply by optimizing of extraction process using response surface methodology.

Characterisation and expression of a PP1 serine/threonine protein phosphatase (PfPP1 from the malaria parasite, Plasmodium falciparum: demonstration of its essential role using RNA interference

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Musiyenko Alla

2002-04-01

Full Text Available Abstract Background Reversible protein phosphorylation is relatively unexplored in the intracellular protozoa of the Apicomplexa family that includes the genus Plasmodium, to which belong the causative agents of malaria. Members of the PP1 family represent the most highly conserved protein phosphatase sequences in phylogeny and play essential regulatory roles in various cellular pathways. Previous evidence suggested a PP1-like activity in Plasmodium falciparum, not yet identified at the molecular level. Results We have identified a PP1 catalytic subunit from P. falciparum and named it PfPP1. The predicted primary structure of the 304-amino acid long protein was highly similar to PP1 sequences of other species, and showed conservation of all the signature motifs. The purified recombinant protein exhibited potent phosphatase activity in vitro. Its sensitivity to specific phosphatase inhibitors was characteristic of the PP1 class. The authenticity of the PfPP1 cDNA was further confirmed by mutational analysis of strategic amino acid residues important in catalysis. The protein was expressed in all erythrocytic stages of the parasite. Abrogation of PP1 expression by synthetic short interfering RNA (siRNA led to inhibition of parasite DNA synthesis. Conclusions The high sequence similarity of PfPP1 with other PP1 members suggests conservation of function. Phenotypic gene knockdown studies using siRNA confirmed its essential role in the parasite. Detailed studies of PfPP1 and its regulation may unravel the role of reversible protein phosphorylation in the signalling pathways of the parasite, including glucose metabolism and parasitic cell division. The use of siRNA could be an important tool in the functional analysis of Apicomplexan genes.

Tension-Induced Error Correction and Not Kinetochore Attachment Status Activates the SAC in an Aurora-B/C-Dependent Manner in Oocytes.

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Vallot, Antoine; Leontiou, Ioanna; Cladière, Damien; El Yakoubi, Warif; Bolte, Susanne; Buffin, Eulalie; Wassmann, Katja

2018-01-08

Cell division with partitioning of the genetic material should take place only when paired chromosomes named bivalents (meiosis I) or sister chromatids (mitosis and meiosis II) are correctly attached to the bipolar spindle in a tension-generating manner. For this to happen, the spindle assembly checkpoint (SAC) checks whether unattached kinetochores are present, in which case anaphase onset is delayed to permit further establishment of attachments. Additionally, microtubules are stabilized when they are attached and under tension. In mitosis, attachments not under tension activate the so-named error correction pathway depending on Aurora B kinase substrate phosphorylation. This leads to microtubule detachments, which in turn activates the SAC [1-3]. Meiotic divisions in mammalian oocytes are highly error prone, with severe consequences for fertility and health of the offspring [4, 5]. Correct attachment of chromosomes in meiosis I leads to the generation of stretched bivalents, but-unlike mitosis-not to tension between sister kinetochores, which co-orient. Here, we set out to address whether reduction of tension applied by the spindle on bioriented bivalents activates error correction and, as a consequence, the SAC. Treatment of oocytes in late prometaphase I with Eg5 kinesin inhibitor affects spindle tension, but not attachments, as we show here using an optimized protocol for confocal imaging. After Eg5 inhibition, bivalents are correctly aligned but less stretched, and as a result, Aurora-B/C-dependent error correction with microtubule detachment takes place. This loss of attachments leads to SAC activation. Crucially, SAC activation itself does not require Aurora B/C kinase activity in oocytes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ketoacidosis With Canagliflozin Prescribed for Phosphoinositide 3-Kinase Inhibitor–Induced Hyperglycemia: A Case Report

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Christopher Bowman MD

2017-08-01

Full Text Available Context . Many phosphoinositide-3-kinase (PI3K inhibitors are under trial for cancer treatment. We present a patient taking taselisib who developed ketoacidosis within 1 week of starting canagliflozin. Case Description . A 69-year-old female patient with no previous history of diabetes mellitus was enrolled in a clinical trial for taselisib therapy in stage IV breast cancer. Hyperglycemia treatment with metformin was insufficient and not tolerated. The addition of canagliflozin daily resulted in ketoacidosis and hospitalization within 1 week. Conclusions . This case report brings together 2 poorly understood and relatively understudied disorders of glucose homeostasis: hyperglycemia due to PI3K inhibition and euglycemic ketoacidosis due to dehydration/SGLT2 inhibition. It demonstrates the complexities of glucose management in the setting of PI3K inhibition. PI3K stimulation (via insulin in this setting is counterintuitive; therefore, non–insulin-mediated therapies (eg, metformin, thiazolidinediones might be favored over insulin-mediated therapies.

Cdc14 phosphatase

DEFF Research Database (Denmark)

Machín, Félix; Quevedo Rodriguez, Oliver; Ramos-Pérez, Cristina

2016-01-01

and cancer cells uncontrollably divide, much attention has been put into knocking down CDK activity. However, much less is known on the consequences of interfering with the phosphatases that put an end to the cell cycle. We have addressed in recent years the consequences of transiently inactivating the only...

Involvement of the phosphoinositide 3-kinase/Akt pathway in apoptosis induced by capsaicin in the human pancreatic cancer cell line PANC-1.

Science.gov (United States)

Zhang, Jian-Hong; Lai, Fu-Ji; Chen, Hui; Luo, Jiang; Zhang, Ri-Yuan; Bu, He-Qi; Wang, Zhao-Hong; Lin, Hong-Hai; Lin, Sheng-Zhang

2013-01-01

Capsaicin, one of the major pungent ingredients found in red peppers, has been recently demonstrated to induce apoptosis in various malignant cell lines through an unclear mechanism. In this study, the effect of capsaicin on proliferation and apoptosis in the human pancreatic cancer cell line PANC-1 and its possible mechanism(s) of action were investigated. The results of a Cell Counting Kit-8 (CCK-8) assay revealed that capsaicin significantly decreased the viability of PANC-1 cells in a dose-dependent manner. Capsaicin induced G0/G1 phase cell cycle arrest and apoptosis in PANC-1 cells as demonstrated by a flow cytometric assessment. Caspase-3 expression at both the protein and mRNA level was promoted following capsaicin treatment. Furthermore, we revealed that phospho-PI3 Kinase p85 (Tyr458) and phospho-Akt (Ser473) in PANC-1 cells were downregulated in response to capsaicin. Moreover, capsaicin gavage significantly inhibited the growth of pancreatic cancer PANC-1 cell xenografts in athymic nude mice. An increased number of TUNEL-positive cells and cleaved caspase-3 were observed in capsaicin-treated mice. In vivo, capsaicin downregulated the expression of phospho-PI3 Kinase p85 (Tyr458) and phospho-Akt (Ser473). In conclusion, we have demonstrated that capsaicin is an inhibitor of growth of PANC-1 cells, and downregulation of the phosphoinositide 3-kinase/Akt pathway may be involved in capsaicin-induced apoptosis in vitro and in vivo.

Fine mapping of S37, a locus responsible for pollen and embryo sac sterility in hybrids between Oryza sativa L. and O. glaberrima Steud.

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Shen, Yumin; Zhao, Zhigang; Ma, Hongyang; Bian, Xiaofeng; Yu, Yang; Yu, Xiaowen; Chen, Haiyuan; Liu, Linglong; Zhang, Wenwei; Jiang, Ling; Zhou, Jiawu; Tao, Dayun; Wan, Jianmin

2015-11-01

Hybrid sterility locus S37 between Oryza glaberrima and Oryza sativa results in both pollen and embryo sac sterility. Interspecific crossing between African cultivated rice Oryza glaberrima and Oryza sativa cultivars is hindered by hybrid sterility. To dissect the mechanism of interspecific hybrid sterility, we developed a near-isogenic line (NIL)-S37 using Dianjingyou1 (DJY1) as the recipient parent and an African cultivated rice variety as the donor parent. Empty pollen and embryo sac sterility were observed in F1 hybrids between DJY1 and NIL-S37. Cytological analyses showed that pollen abortion in the F1 hybrids occurred at the late binucleate stage due to a failure of starch accumulation in pollen grains. In addition, partial abortion of the embryo sac in the F1 hybrid was observed during function megaspore developing into mature embryo sac. Molecular analysis revealed that the semi-sterility was largely caused by the abortion of male and female gametophytes carrying the S37 allele from DJY1. A population of 25,600 plants derived from the hybrid DJY1/NIL-S37 was developed to fine map S37. Based on the physical location of molecular markers, S37 locus was finally delimited to a region of 205 kb on the short arm of chromosome 1 in terms of reference sequences of cv. Nipponbare. Interestingly, an about 97-kb DNA segment was deleted in the NIL-S37 based on BAC clone information of O. glaberrima. Fifty-four open reading frames (ORF) were predicted in this 205-kb region of DJY1, whereas only 31 ORFs were in that of NIL-S37. These results are valuable for cloning of S37 gene and further breaking reproductive isolation between Oryza glaberrima and Oryza sativa cultivars, as well as marker-assisted transferring of the corresponding neutral allele in rice breeding programs.

A unified nomenclature and amino acid numbering for human PTEN

NARCIS (Netherlands)

Pulido, Rafael; Baker, Suzanne J; Barata, Joao T; Carracedo, Arkaitz; Cid, Victor J; Chin-Sang, Ian D; Davé, Vrushank; den Hertog, Jeroen; Devreotes, Peter; Eickholt, Britta J; Eng, Charis; Furnari, Frank B; Georgescu, Maria-Magdalena; Gericke, Arne; Hopkins, Benjamin; Jiang, Xeujun; Lee, Seung-Rock; Lösche, Mathias; Malaney, Prerna; Matias-Guiu, Xavier; Molina, María; Pandolfi, Pier Paolo; Parsons, Ramon; Pinton, Paolo; Rivas, Carmen; Rocha, Rafael M; Rodríguez, Manuel S; Ross, Alonzo H; Serrano, Manuel; Stambolic, Vuk; Stiles, Bangyan; Suzuki, Akira; Tan, Seong-Seng; Tonks, Nicholas K; Trotman, Lloyd C; Wolff, Nicolas; Woscholski, Rudiger; Wu, Hong; Leslie, Nicholas R

2014-01-01

The tumor suppressor PTEN is a major brake for cell transformation, mainly due to its phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P3] phosphatase activity that directly counteracts the oncogenicity of phosphoinositide 3-kinase (PI3K). PTEN mutations are frequent in tumors and in the germ line

The TriTryp Phosphatome: analysis of the protein phosphatase catalytic domains

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Huxley-Jones Julie

2007-11-01

Full Text Available Abstract Background The genomes of the three parasitic protozoa Trypanosoma cruzi, Trypanosoma brucei and Leishmania major are the main subject of this study. These parasites are responsible for devastating human diseases known as Chagas disease, African sleeping sickness and cutaneous Leishmaniasis, respectively, that affect millions of people in the developing world. The prevalence of these neglected diseases results from a combination of poverty, inadequate prevention and difficult treatment. Protein phosphorylation is an important mechanism of controlling the development of these kinetoplastids. With the aim to further our knowledge of the biology of these organisms we present a characterisation of the phosphatase complement (phosphatome of the three parasites. Results An ontology-based scan of the three genomes was used to identify 86 phosphatase catalytic domains in T. cruzi, 78 in T. brucei, and 88 in L. major. We found interesting differences with other eukaryotic genomes, such as the low proportion of tyrosine phosphatases and the expansion of the serine/threonine phosphatase family. Additionally, a large number of atypical protein phosphatases were identified in these species, representing more than one third of the total phosphatase complement. Most of the atypical phosphatases belong to the dual-specificity phosphatase (DSP family and show considerable divergence from classic DSPs in both the domain organisation and sequence features. Conclusion The analysis of the phosphatome of the three kinetoplastids indicates that they possess orthologues to many of the phosphatases reported in other eukaryotes, including humans. However, novel domain architectures and unusual combinations of accessory domains, suggest distinct functional roles for several of the kinetoplastid phosphatases, which await further experimental exploration. These distinct traits may be exploited in the selection of suitable new targets for drug development to prevent

Microwave induced stimulation of 32Pi incorporation into phosphoinositides of rat brain synaptosomes

International Nuclear Information System (INIS)

Gandhi, C.R.; Ross, D.H.

1989-01-01

Exposure of synaptosomes to microwave radiation at a power density of 10 mW/sq cm or more produced stimulation of the 32 Pi-incorporation into phosphoinositides. The extent of 32 Pi incorporation was found to be much more pronounced in phosphatidylinositol-4-phosphate (PIP), and phosphatidylinositol-4,5-bisphosphate (PIP 2 ) as compared to phosphatidylinositol (PI) and phosphatidic acid (PA). Other lipids were also found to incorporate 32 Pi but no significant changes in their labeling were seen after exposure to microwave radiation. Inclusion of 10 mM lithium in the medium reduced the basal labeling of PIP 2 , PIP and PI and increased PA labeling. Li + also inhibited the microwave stimulated PIP 2 , PIP and PI labeling but had no effect on PA labeling. Calcium inophore, A 23187 , inhibited the basal and microwave stimulated 32 Pi labeling of PIP and PIP 2 , stimulated basal labeling of PA and PI and had no effect on microwave stimulated PA and PI labeling. Calcium chelator, EGTA, on the other hand, had no effect on basal labeling of PA and PI, stimulated basal PIP and PIP 2 labeling but did not alter microwave stimulated labeling of these lipids. Exposure of synaptosomes to microwave radiation did not alter the chemical concentration of phosphoinositides indicating that the turnover of these lipids was altered. These results suggest that low frequency microwave radiation alter the metabolism of inositol phospholipids by enhancing their turnover and thus may affect the transmembrane signalling in the nerve endings. (orig.)

Deficiency in Protein Tyrosine Phosphatase PTP1B Shortens Lifespan and Leads to Development of Acute Leukemia.

Science.gov (United States)

Le Sommer, Samantha; Morrice, Nicola; Pesaresi, Martina; Thompson, Dawn; Vickers, Mark A; Murray, Graeme I; Mody, Nimesh; Neel, Benjamin G; Bence, Kendra K; Wilson, Heather M; Delibegović, Mirela

2018-01-01

Protein tyrosine phosphatase PTP1B is a critical regulator of signaling pathways controlling metabolic homeostasis, cell proliferation, and immunity. In this study, we report that global or myeloid-specific deficiency of PTP1B in mice decreases lifespan. We demonstrate that myeloid-specific deficiency of PTP1B is sufficient to promote the development of acute myeloid leukemia. LysM-PTP1B -/- mice lacking PTP1B in the innate myeloid cell lineage displayed a dysregulation of bone marrow cells with a rapid decline in population at midlife and a concomitant increase in peripheral blood blast cells. This phenotype manifested further with extramedullary tumors, hepatic macrophage infiltration, and metabolic reprogramming, suggesting increased hepatic lipid metabolism prior to overt tumor development. Mechanistic investigations revealed an increase in anti-inflammatory M2 macrophage responses in liver and spleen, as associated with increased expression of arginase I and the cytokines IL10 and IL4. We also documented STAT3 hypersphosphorylation and signaling along with JAK-dependent upregulation of antiapoptotic proteins Bcl2 and BclXL. Our results establish a tumor suppressor role for PTP1B in the myeloid lineage cells, with evidence that its genetic inactivation in mice is sufficient to drive acute myeloid leukemia. Significance: This study defines a tumor suppressor function for the protein tyrosine phosphatase PTP1B in myeloid lineage cells, with evidence that its genetic inactivation in mice is sufficient to drive acute myeloid leukemia. Cancer Res; 78(1); 75-87. ©2017 AACR . ©2017 American Association for Cancer Research.

Overexpression of Human Bone Alkaline Phosphatase in Pichia Pastoris

Science.gov (United States)

Karr, Laurel; Malone, Christine, C.; Rose, M. Franklin (Technical Monitor)

2000-01-01

The Pichiapastoris expression system was utilized to produce functionally active human bone alkaline phosphatase in gram quantities. Bone alkaline phosphatase is a key enzyme in bone formation and biomineralization, yet important questions about its structural chemistry and interactions with other cellular enzymes in mineralizing tissues remain unanswered. A soluble form of human bone alkaline phosphatase was constructed by deletion of the 25 amino acid hydrophobic C-terminal region of the encoding cDNA and inserted into the X-33 Pichiapastoris strain. An overexpression system was developed in shake flasks and converted to large-scale fermentation. Alkaline phosphatase was secreted into the medium to a level of 32mgAL when cultured in shake flasks. Enzyme activity was 12U/mg measured by a spectrophotometric assay. Fermentation yielded 880mgAL with enzymatic activity of 968U/mg. Gel electrophoresis analysis indicates that greater than 50% of the total protein in the fermentation is alkaline phosphatase. A purification scheme has been developed using ammonium sulfate precipitation followed by hydrophobic interaction chromatography. We are currently screening crystallization conditions of the purified recombinant protein for subsequent X-ray diffraction analyses. Structural data should provide additional information on the role of alkaline phosphatase in normal bone mineralization and in certain bone mineralization anomalies.

Central regulation of metabolism by protein tyrosine phosphatases

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Ryan eTsou

2013-01-01

Full Text Available Protein tyrosine phosphatases (PTPs are important regulators of intracellular signaling pathways via the dephosphorylation of phosphotyrosyl residues on various receptor and non-receptor substrates. The phosphorylation state of central nervous system (CNS signaling components underlies the molecular mechanisms of a variety of physiological functions including the control of energy balance and glucose homeostasis. In this review, we summarize the current evidence implicating PTPs as central regulators of metabolism, specifically highlighting their interactions with the neuronal leptin and insulin signaling pathways. We discuss the role of a number of PTPs (PTP1B, SHP2, TCPTP, RPTPe, and PTEN, reviewing the findings from genetic mouse models and in vitro studies which highlight these phosphatases as key central regulators of energy homeostasis.

A new two-code keying scheme for SAC-OCDMA systems enabling bipolar encoding

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Al-Khafaji, Hamza M. R.; Ngah, Razali; Aljunid, S. A.; Rahman, T. A.

2015-03-01

In this paper, we propose a new two-code keying scheme for enabling bipolar encoding in a high-rate spectral-amplitude coding optical code-division multiple-access (SAC-OCDMA) system. The mathematical formulations are derived for the signal-to-noise ratio and bit-error rate (BER) of SAC-OCDMA system based on the suggested scheme using multi-diagonal (MD) code. Performance analyses are assessed considering the effects of phase-induced intensity noise, as well as shot and thermal noises in photodetectors. The numerical results demonstrated that the proposed scheme exhibits an enhanced BER performance compared to the existing unipolar encoding with direct detection technique. Furthermore, the performance improvement afforded by this scheme is verified using simulation experiments.

Alkaline phosphatase activity in gingival crevicular fluid during canine retraction.

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Batra, P; Kharbanda, Op; Duggal, R; Singh, N; Parkash, H

2006-02-01

The aim of the study was to investigate alkaline phosphatase activity in the gingival crevicular fluid (GCF) during orthodontic tooth movement in humans. Postgraduate orthodontic clinic. Ten female patients requiring all first premolar extractions were selected and treated with standard edgewise mechanotherapy. Canine retraction was done using 100 g sentalloy springs. Maxillary canine on one side acted as experimental site while the contralateral canine acted as control. Gingival crevicular fluid was collected from mesial and distal of canines before initiation of canine retraction (baseline), immediately after initiation of retraction, and on 1st, 7th, 14th and 21st day and the alkaline phosphatase activity was estimated. The results show significant (p < 0.05) changes in alkaline phosphatase activity on the 7th, 14th and 21st day on both mesial and distal aspects of the compared experimental and control sides. The peak in enzyme activity occurred on the 14th day of initiation of retraction followed by a significant fall in activity especially on the mesial aspect. The study showed that alkaline phosphatase activity could be successfully estimated in the GCF using calorimetric estimation assay kits. The enzyme activity showed variation according to the amount of tooth movement.

Fine structures of the ejaculatory sac and sperm pump of the scorpionfly Panorpa liui Hua (Mecoptera: Panorpidae).

Science.gov (United States)

Shen, Jian; Hua, Baozhen

2013-08-01

Male adults of Panorpidae possess a special sperm pump, through which the males transfer liquid sperm to the females. However, the structures of the sperm pump and the transfer mechanism have not been satisfactorily elucidated hitherto. In this paper the structures of the ejaculatory sac and sperm pump of the scorpionfly Panorpa liui Hua were investigated using light microscopy and scanning electron microscopy. The ejaculatory sac is located between the basal end of the paired vasa deferentia and the aedeagus, comprising a small anterior part and a large posterior part. The anterior part is simple and functions only as a channel for sperm transfer. The epithelial cells of the large posterior part likely have secretory functions. The sperm pump is formed by the posterior region of the ejaculatory sac and derivates of the genital field, which enclose the pumping chamber, a piston and the associated muscles. The orifice of the ejaculatory duct lies ventrad of the piston. The piston of the sperm pump is heavily sclerotized and controlled by two antagonistic muscle pairs. A pair of simple tubular accessory glands opens to the pumping chamber. Two well-developed sex pheromone glands are located on the ventral side of the ejaculatory sac, and are composed of two fan-shaped lamellae. The epithelium of the sex pheromone glands is single-layered, and forms densely filamentous processes. The ejaculation mechanism is briefly discussed based on the morphology of ejaculatory sac and sperm pump. Copyright © 2013 Elsevier Ltd. All rights reserved.

Downregulation of PTP1B and TC-PTP phosphatases potentiate dendritic cell-based immunotherapy through IL-12/IFNγ signaling.

Science.gov (United States)

Penafuerte, Claudia; Feldhammer, Matthew; Mills, John R; Vinette, Valerie; Pike, Kelly A; Hall, Anita; Migon, Eva; Karsenty, Gerard; Pelletier, Jerry; Zogopoulos, George; Tremblay, Michel L

2017-01-01

PTP1B and TC-PTP are highly related protein-tyrosine phosphatases (PTPs) that regulate the JAK/STAT signaling cascade essential for cytokine-receptor activation in immune cells. Here, we describe a novel immunotherapy approach whereby monocyte-derived dendritic cell (moDC) function is enhanced by modulating the enzymatic activities of PTP1B and TC-PTP. To downregulate or delete the activity/expression of these PTPs, we generated mice with PTP-specific deletions in the dendritic cell compartment or used PTP1B and TC-PTP specific inhibitor. While total ablation of PTP1B or TC-PTP expression leads to tolerogenic DCs via STAT3 hyperactivation, downregulation of either phosphatase remarkably shifts the balance toward an immunogenic DC phenotype due to hyperactivation of STAT4, STAT1 and Src kinase. The resulting increase in IL-12 and IFNγ production subsequently amplifies the IL-12/STAT4/IFNγ/STAT1/IL-12 positive autocrine loop and enhances the therapeutic potential of mature moDCs in tumor-bearing mice. Furthermore, pharmacological inhibition of both PTPs improves the maturation of defective moDCs derived from pancreatic cancer (PaC) patients. Our study provides a new advance in the use of DC-based cancer immunotherapy that is complementary to current cancer therapeutics.

A Novel Technique to Detect Code for SAC-OCDMA System

Science.gov (United States)

Bharti, Manisha; Kumar, Manoj; Sharma, Ajay K.

2018-04-01

The main task of optical code division multiple access (OCDMA) system is the detection of code used by a user in presence of multiple access interference (MAI). In this paper, new method of detection known as XOR subtraction detection for spectral amplitude coding OCDMA (SAC-OCDMA) based on double weight codes has been proposed and presented. As MAI is the main source of performance deterioration in OCDMA system, therefore, SAC technique is used in this paper to eliminate the effect of MAI up to a large extent. A comparative analysis is then made between the proposed scheme and other conventional detection schemes used like complimentary subtraction detection, AND subtraction detection and NAND subtraction detection. The system performance is characterized by Q-factor, BER and received optical power (ROP) with respect to input laser power and fiber length. The theoretical and simulation investigations reveal that the proposed detection technique provides better quality factor, security and received power in comparison to other conventional techniques. The wide opening of eye in case of proposed technique also proves its robustness.

Lesser sac hematoma as a sign of rupture of hepatocellular carcinoma in the caudate lobe

International Nuclear Information System (INIS)

Iwasaki, Yoshie; Tani, Ichiro; Nakajima, Yasuo; Ishikawa, Tohru; Umeda, Satoshi; Kusano, Shoichi

2001-01-01

The purpose of this study was to evaluate the CT findings of rupture of hepatocellular carcinoma (HCC) in the caudate lobe of the liver. The CT scans of five cases of rupture of HCC in the caudate lobe of the liver were retrospectively reviewed and correlated with clinical records. All cases showed exophytic tumors in the caudate lobe of the liver and high-attenuation hematomas in the lesser sac on CT. A lesser sac hematoma may be a sentinel clot sign of rupture of HCC in the caudate lobe. (orig.)

The tillage effect on the soil acid and alkaline phosphatase activity

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Lacramioara Oprica

2011-12-01

Full Text Available Phosphatases (acid and alkaline are important in soils because these extracellular enzymes catalyze the hydrolysis of organic phosphate esters to orthophosphate; thus they form an important link between biologically unavailable and mineral phosphorous. Phosphatase activity is sensitive to environmental perturbations such as organic amendments, tillage, waterlogging, compaction, fertilizer additions and thus it is often used as an environmental indicator of soil quality in riparian ecosystems. The aim of the study was to assess the effect of tillage systems on phosphatases activity in a field experiment carried out in Ezăreni farm. The phosphatase activitiy were determined at two depths (7-10 cm and 15-25cm layers of a chernozem soil submitted to conventional tillage (CT in a fertilised and unfertilised experiment. Monitoring soil alkaline phosphatase activity showed, generally, the same in fertilized soil profiles collected from both depths; the values being extremely close. In unfertilized soils, alkaline phosphatase activity is different only in soils that were exposed to unconventional work using disc harrows and 30cm tillage. Both works type (no tillage and conventional tillage cause an intense alkaline phosphatase activity in 7-10 cm soil profile. Acid phosphatase activity is highly fluctuating in both fertilized as well unfertilized soil, this enzyme being influenced by the performed works.

Membrane-bound 2,3-diphosphoglycerate phosphatase of human erythrocytes.

Science.gov (United States)

Schröter, W; Neuvians, M

1970-12-01

Gradual osmotic hemolysis of human erythrocytes reduces the cell content of whole protein, hemoglobin, 2,3-diphosphoglycerate and triosephosphate isomerase extensively, but not that of membrane protein and 2,3-diphosphoglycerate phosphatase. After the refilling of the ghosts with 2,3-diphosphoglycerate and reconstitution of the membrane, the 2,3-diphosphoglycerate phosphatase activity equals that of intact red cells. The membrane-bound 2,3-diphosphoglycerate phosphatase can be activated by sodium hyposulfite. The enzyme system of ghosts seems to differ from that of intact red cells with regard to the optima of pH and temperature. It remains to be elucidated if the membrane binding of the 2,3-diphosphoglycerate phosphatase is related to the transfer of inorganic phosphate across the red cell membrane.

Enzymatic exchange of sulphur between cysteine and hydrogen sulphide in the yolk sac of an incubated bird's egg

International Nuclear Information System (INIS)

Chapeville, F.; Fromageot, P.

1960-01-01

Previous work has shown that the formation of cysteic acid from sulphate in incubated hen's eggs is due to the following reactions: a) reduction of sulphate to sulphite by the yolk sac endoderm cells; b) synthesis of cysteic acid from the sulphite in the presence of cysteine with liberation of hydrogen sulphide: HS-CH 2 -CH(NH 2 )-COOH + SO 3 H - → H 2 S + - O 3 S-CH 2 -CH(NH 2 )-COOH (1). The enzymatic system responsible for this reaction is localized on the yolk sac endoderm and in the yolk. It may be wondered whether reaction (1) is not made up of two consecutive reactions, one of which is reversible: HS-CH 2 -CH(NH 2 )-COOH ↔ H 2 S + organic chain (2) and organic chain + SO 3 H - → - O 3 S-CH 2 -CH(NH 2 )-COOH (3). It would then be clear why the addition of sulphite displaces the equilibrium towards the production of cysteic acid and hydrogen sulphide. If this is the case, the addition of ordinary cysteine and of marked hydrogen sulphide to the biological medium should make it possible to detect the formation of 35 S cysteine. The present work shows that the desulphurization of the cysteine (reaction 2) by the yolk sac + the yolk is in fact a reversible reaction, and that an enzymatic exchange occurs between the sulphur of the cysteine and that of the hydrogen sulphide. (author) [fr

Endoplasmic reticulum stress-induced apoptosis accompanies enhanced expression of multiple inositol polyphosphate phosphatase 1 (Minpp1): a possible role for Minpp1 in cellular stress response.

Science.gov (United States)

Kilaparty, Surya P; Agarwal, Rakhee; Singh, Pooja; Kannan, Krishnaswamy; Ali, Nawab

2016-07-01

Inositol polyphosphates represent a group of differentially phosphorylated inositol metabolites, many of which are implicated to regulate diverse cellular processes such as calcium mobilization, vesicular trafficking, differentiation, apoptosis, etc. The metabolic network of these compounds is complex and tightly regulated by various kinases and phosphatases present predominantly in the cytosol. Multiple inositol polyphosphate phosphatase 1 (Minpp1) is the only known endoplasmic reticulum (ER) luminal enzyme that hydrolyzes various inositol polyphosphates in vitro as well as in vivo conditions. However, access of the Minpp1 to cytosolic substrates has not yet been demonstrated clearly and hence its physiological function. In this study, we examined a potential role for Minpp1 in ER stress-induced apoptosis. We generated a custom antibody and characterized its specificity to study the expression of Minpp1 protein in multiple mammalian cells under experimentally induced cellular stress conditions. Our results demonstrate a significant increase in the expression of Minpp1 in response to a variety of cellular stress conditions. The protein expression was corroborated with the expression of its mRNA and enzymatic activity. Further, in an attempt to link the role of Minpp1 to apoptotic stress, we studied the effect of Minpp1 expression on apoptosis following silencing of the Minpp1 gene by its specific siRNA. Our results suggest an attenuation of apoptotic parameters following knockdown of Minpp1. Thus, in addition to its known role in inositol polyphosphate metabolism, we have identified a novel role for Minpp1 as a stress-responsive protein. In summary, our results provide, for the first time, a probable link between ER stress-induced apoptosis and Minpp1 expression.

MAPK Phosphatase-1 Deficiency Exacerbates the Severity of Imiquimod-Induced Psoriasiform Skin Disease

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Weiheng Zhao

2018-03-01

Full Text Available Persistent activation of mitogen-activated protein kinase (MAPK is believed to be involved in psoriasis pathogenesis. MAPK phosphatase-1 (MKP-1 is an important negative regulator of MAPK activity, but the cellular and molecular mechanisms of MKP-1 in psoriasis development are largely unknown. In this study, we found that the expression of MKP-1 was decreased in the imiquimod (IMQ-induced psoriasiform mouse skin. MKP-1-deficient (MKP-1−/− mice were highly susceptible to IMQ-induced skin inflammation, which was associated with increased production of inflammatory cytokines and chemokines. MKP-1 acted on both hematopoietic and non-hematopoietic cells to regulate psoriasis pathogenesis. MKP-1 deficiency in macrophages led to enhanced p38 activation and higher expression of interleukin (IL-1β, CXCL2, and S100a8 upon R848 stimulation. Moreover, MKP-1 deficiency in the non-hematopoietic compartments led to an enhanced IL-22 receptor signaling and higher expression of CXCL1 and CXCL2 upon IMQ treatment. Collectively, our data suggest a critical role for MKP-1 in the regulation of skin inflammation.

Characterization of Human Bone Alkaline Phosphatase in Pichia Pastoris

Science.gov (United States)

Malone, Christine C.; Ciszak, Eva; Karr, Laurel J.

1999-01-01

A soluble form of human bone alkaline phosphatase has been expressed in a recombinant strain of the methylotrophic yeast Pichia pastoris. We constructed a plasmid containing cDNA encoding for human bone alkaline phosphatase, with the hydrophobic carboxyl terminal portion deleted. Alkaline phosphatase was secreted into the medium to a level of 32mg/L when cultured in shake flasks, and enzyme activity was 12U/mg, as measured by a spectrophotometric assay. By conversion to a fermentation system, a yield of 880mg/L has been achieved with an enzyme activity of 968U/mg. By gel electrophoresis analysis, it appears that greater than 50% of the total protein in the fermentation media is alkaline phosphatase. Although purification procedures are not yet completely optimized, they are expected to include filtration, ion exchange and affinity chromatography. Our presentation will focus on the purification and crystallization results up to the time of the conference. Structural data should provide additional information on the role of alkaline phosphatase in normal bone mineralization and in certain bone mineralization anomalies.

Regulation of brown fat adipogenesis by protein tyrosine phosphatase 1B.

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Kosuke Matsuo

2011-01-01

Full Text Available Protein-tyrosine phosphatase 1B (PTP1B is a physiological regulator of insulin signaling and energy balance, but its role in brown fat adipogenesis requires additional investigation.To precisely determine the role of PTP1B in adipogenesis, we established preadipocyte cell lines from wild type and PTP1B knockout (KO mice. In addition, we reconstituted KO cells with wild type, substrate-trapping (D/A and sumoylation-resistant (K/R PTP1B mutants, then characterized differentiation and signaling in these cells. KO, D/A- and WT-reconstituted cells fully differentiated into mature adipocytes with KO and D/A cells exhibiting a trend for enhanced differentiation. In contrast, K/R cells exhibited marked attenuation in differentiation and lipid accumulation compared with WT cells. Expression of adipogenic markers PPARγ, C/EBPα, C/EBPδ, and PGC1α mirrored the differentiation pattern. In addition, the differentiation deficit in K/R cells could be reversed completely by the PPARγ activator troglitazone. PTP1B deficiency enhanced insulin receptor (IR and insulin receptor substrate 1 (IRS1 tyrosyl phosphorylation, while K/R cells exhibited attenuated insulin-induced IR and IRS1 phosphorylation and glucose uptake compared with WT cells. In addition, substrate-trapping studies revealed that IRS1 is a substrate for PTP1B in brown adipocytes. Moreover, KO, D/A and K/R cells exhibited elevated AMPK and ACC phosphorylation compared with WT cells.These data indicate that PTP1B is a modulator of brown fat adipogenesis and suggest that adipocyte differentiation requires regulated expression of PTP1B.

Osteocalcin and bone-specific alkaline phosphatase in Sickle cell ...

African Journals Online (AJOL)

specific alkaline phosphatase (b-AP) total protein levels were evaluated as indicators of bone turnover in twenty patients with sickle cell haemoglobinopathies and in twenty normal healthy individuals. The serum bonespecific alkaline phosphatase ...

Research on Phosphatases of Belladona Leaves and Their Purification

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M. Khorsand

1957-01-01

Full Text Available Through experimentation with several leaves it has been possible for us to point out the existance of two different acid phosphatases. We have studied in more detail the phosphatases of belldon a leaves (Atropa Belladona L. Solanacees. The great part of the phosphatase activity is water extractable. We have compared the activity of the soluble fraction with that not directly extractable by means of water. The insoluble fraction could not be solubilized in a satisfaetC'fY m.anner.The digestion by papaine produced a slight solubilizing effect; on the other hand salt solutions, neutral or alkaline, or water glycerol mixtures had no solubilizing effect on the enzyme, It has been possible to demonstrate the existence of two different phosphatases in the insoluble fraction: the first of the type II,

Fungi infection in honeybee hives in regions affected by Brazilian sac brood

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K.M. Keller

2014-10-01

Full Text Available The Brazilian Sac Brood is a disease that affects apiaries of Africanized bee hives in Brazil, thereby making them susceptible to high losses. This study investigated the pathogenicity of Africanized bee hives by the entomopathogenic fungi in a Brazilian Sac Brood endemic region. The degree of fungal contamination, presence of mycotoxins in beehive elements, and vulnerability of healthy beehives in environments subjected and not subjected to the disease were investigated. From the contaminating fungal load, species that are mycotoxin producers and pathogenic causing mortality in the bees have been isolated. The analysis of bee pollen and bee bread samples did not show the presence of the toxic pollen of Stryphnodendron (Fabaceae, which has been indicated as the causative agent of mortality in pre-pupal stage larvae. However, bee bread showed the highest correlation between substrate and fungal contamination.

Improved BER based on intensity noise alleviation using developed detection technique for incoherent SAC-OCDMA systems

Science.gov (United States)

Al-Khafaji, Hamza M. R.; Aljunid, S. A.; Fadhil, Hilal A.

2012-06-01

The major drawback of incoherent spectral-amplitude coding optical code-division multiple-access (SAC-OCDMA) systems is their inherent intensity noise originating due to the incoherency of the broadband light sources. In this paper, we propose a developed detection technique named the modified-AND subtraction detection for incoherent SAC-OCDMA systems. This detection technique is based upon decreasing the received signal strength during the decoding process by dividing the spectrum of the utilized code sequence. The proposed technique is capable of mitigating the intensity noise effect, as well as suppressing the multiple-access interference impact. Based on modified quadratic congruence (MQC) code, the analytical results reveal that the modified-AND detection offer best bit-error rate (BER) performance and enables MQC code to support higher transmission rate up to 1.25 Gb/s compared to conventional AND detection. Furthermore, we ascertained that the proposed technique enhances the system performance using a simulation experiment.

Defining Starch Binding by Glucan Phosphatases

DEFF Research Database (Denmark)

Auger, Kyle; Raththagala, Madushi; Wilkens, Casper

2015-01-01

Starch is a vital energy molecule in plants that has a wide variety of uses in industry, such as feedstock for biomaterial processing and biofuel production. Plants employ a three enzyme cyclic process utilizing kinases, amylases, and phosphatases to degrade starch in a diurnal manner. Starch...... is comprised of the branched glucan amylopectin and the more linear glucan amylose. Our lab has determined the first structures of these glucan phosphatases and we have defined their enzymatic action. Despite this progress, we lacked a means to quickly and efficiently quantify starch binding to glucan...

Alkaline phosphatase levels in patients with coronary heart disease saliva and its relation with periodontal status

Science.gov (United States)

Yunita, Dina Suci; Masulili, Sri Lelyati C.; Tadjoedin, Fatimah M.; Radi, Basuni

2017-02-01

Coronary heart disease (CHD) is a disease that causes narrowing of the coronary arteries. Currently, there is a hypothesis regarding periodontal infection that increases risk for heart disease. Alkaline phosphatase (ALP) as a marker of inflammation will increase in atherosclerosis and periodontal disease. The objective of this research is analyzing the relationship between the levels of alkaline phosphatase in saliva with periodontal status in patients with CHD and non CHD. Here, saliva of 104 subjects were taken, each 1 ml, and levels of Alkaline Phosphatase was analyzed using Abbott ci4100 architect. We found that no significant difference of Alkaline Phosphatase levels in saliva between CHD patients and non CHD. Therefore, it can be concluded that Alkaline Phosphatase levels in patients with CHD saliva was higher than non CHD and no association between ALP levels with periodontal status.

Tyrosine phosphorylation in T cells is regulated by phosphatase activity: studies with phenylarsine oxide.

OpenAIRE

Garcia-Morales, P; Minami, Y; Luong, E; Klausner, R D; Samelson, L E

1990-01-01

Activation of T cells induces rapid tyrosine phosphorylation on the T-cell receptor zeta chain and other substrates. These phosphorylations can be regulated by a number of protein-tyrosine kinases (ATP: protein-tyrosine O-phosphotransferase, EC 2.7.1.112) and protein-tyrosine-phosphatases (protein-tyrosine-phosphate phosphohydrolase, EC 3.1.3.48). In this study, we demonstrate that phenylarsine oxide can inhibit tyrosine phosphatases while leaving tyrosine kinase function intact. We use this ...

Phosphoinositide-3-kinases p110alpha and p110beta mediate S phase entry in astroglial cells in the marginal zone of rat neocortex

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Rabea eMüller

2013-03-01

Full Text Available In cells cultured from neocortex of newborn rats, phosphoinositide-3-kinases of class I regulate the DNA synthesis in a subgroup of astroglial cells. We have studied the location of these cells as well as the kinase isoforms which facilitate the S phase entry. Using dominant negative isoforms as well as selective pharmacological inhibitors we quantified S phase entry by nuclear labeling with bromodeoxyuridine. Only in astroglial cells harvested from the marginal zone of the neocortex inhibition of phosphoinositide-3-kinases reduced the nuclear labeling with bromodeoxyuridine, indicating that neocortical astroglial cells differ in the regulation of proliferation. The two kinase isoforms p110 and p110were essential for S phase entry. p110 diminished the level of the p27Kip1 which inactivates the complex of cyclin E and CDK2 necessary for entry into the S phase. p110phosphorylated and inhibited glycogen synthase kinase-3which can prevent S-phase entry. Taken together, both isoforms mediated S phase in a subgroup of neocortical astroglial cells and acted via distinct pathways.

Response to DNA damage: why do we need to focus on protein phosphatases?

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Midori eShimada

2013-01-01

Full Text Available Eukaryotic cells are continuously threatened by unavoidable errors during normal DNA replication or various sources of genotoxic stresses that cause DNA damage or stalled replication. To maintain genomic integrity, cells have developed a coordinated signaling network, known as the DNA damage response (DDR. Following DNA damage, sensor molecules detect the presence of DNA damage and transmit signals to downstream transducer molecules. This in turn conveys the signals to numerous effectors, which initiate a large number of specific biological responses, including transient cell cycle arrest mediated by checkpoints, DNA repair, and apoptosis. It is recently becoming clear that dephosphorylation events are involved in keeping DDR factors inactive during normal cell growth. Moreover, dephosphorylation is required to shut off checkpoint arrest following DNA damage and has been implicated in the activation of the DDR. Spatial and temporal regulation of phosphorylation events is essential for the DDR, and fine-tuning of phosphorylation is partly mediated by protein phosphatases. While the role of kinases in the DDR has been well documented, the complex roles of protein dephosphorylation have only recently begun to be investigated. Therefore, it is important to focus on the role of phosphatases and to determine how their activity is regulated upon DNA damage. In this work, we summarize current knowledge on the involvement of serine/threonine phosphatases, especially the protein phosphatase 1, protein phosphatase 2A, and protein phosphatase Mg2+/Mn2+-dependent families, in the DDR.

Planeamiento estratégico de Ingeniería de Sistemas de Fluidos S.A.C.

OpenAIRE

Arana, Fernando; Iparraguirre, Miguel; Vásquez, Mariela

2015-01-01

La finalidad del presente trabajo de investigación es la elaboración de un plan estratégico para la empresa Ingeniería de Sistemas de Fluidos SAC para los siguientes tres años. Este plan se inicia analizando el entorno externo en el que se desempeña ISF SAC, tanto el entorno general como el entorno de la industria, de esta manera conocer las oportunidades y amenazas a las que se debe enfrentar la empresa. Una vez analizado el entorno externo, se realiza el análisis interno en el cual se evalú...

Elevated Serum Level of Human Alkaline Phosphatase in Obesity

International Nuclear Information System (INIS)

Khan, A. R.; Awan, F. R.; Najam, S. S.; Islam, M.; Siddique, T.; Zain, M.

2015-01-01

Objective: To investigate a correlation between serum alkaline phosphatase level and body mass index in human subjects. Methods: The comparative cross-sectional study was carried out at the National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan, from April 2012 to June 2013. Blood serum alkaline phosphatase levels were estimated and the subjects were divided into three sub-groups on the basis of their body mass index: normal weight (<25kg/m2), overweight (25-27kg/m2) and obese (>27kg/m2) subjects. The serum samples were used for the estimation of clinically important biochemical parameters, using commercial kits on clinical chemistry analyser. Results: Of the 197 subjects, 97(49 percent) were obese and 100(51 percent) were non-obese. The serum alkaline phosphatase level increased in obese (214±6.4 IU/L) compared to the non-obese subjects (184.5±5 IU/L). Furthermore, a significant linear relationship (r=0.3;p-0.0001) was found between serum alkaline phosphatase and body mass index. Other biochemical variables were not correlated to the body mass index. Conclusion: Over activity and higher amounts of alkaline phosphatase were linked to the development of obesity. (author)

Clinical analysis of endoscopic common canaliculus opening operation for lacrimal sac anastomotic occlusion

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Yang-Yang Xie

2016-01-01

Full Text Available AIM:To investigate the effect and safety of endoscopic common canaliculus opening operation for lacrimal sac anastomotic occlusion, in order to guide the clinical application.METHODS:Retrospective clinical study. Sixty-six patients(70 eyeswith lacrimal sac anastomotic occlusion were selected as the research subjects. All patients were treated by endoscopic common canaliculus opening operation. The post-operation follow-up lasted for 3～24mo. Subjective feelings of patients were recorded through the collection of clinical data, out-patient follow-up and telephone follow-up. The operation effect and complications were observed, as well as the effect of treatment on complications. Meanwhile, the data was analyzed for evaluating the clinical efficacy of endoscopic common canaliculus opening operation.RESULTS:Epiphora was disappeared or obviously improved in 68 eyes(97%, with lacrimal irrigating fluently and no obstacle. The post-operative complications included:51 eyes(73%with foreign body sensation in inner canthus, 22 eyes(31%with foreign body sensation in the nose occasionally, 4 eyes(6%with granulation tissue proliferation at the opening of common canaliculus, 16 eyes(23%with localized congestion of the bulbar conjunctiva, and 3 eyes(4%with lacrimal drainage tube out.CONCLUSION: Endoscopic common canaliculus opening operation can treat the lacrimal sac anastomotic occlusion. This operation is characterized by high success rate, less complications, safe and efficient, and it is worth clinical promotion.

[Effect of elevated atmospheric CO2 on soil urease and phosphatase activities].

Science.gov (United States)

Chen, Lijun; Wu, Zhijie; Huang, Guohong; Zhou, Likai

2002-10-01

The response of soil urease and phosphatase activities at different rice growth stages to free air CO2 enrichment (FACE) was studied. The results showed that comparing with the ambient atmospheric CO2 concentration (370 mumol.mol-1), FACE (570 mumol.mol-1) significantly increased the urease activity of 0-5 cm soil layer at the vigorous growth stage of rice, whole that of 5-10 cm layer had no significant change during the whole growing season. Phosphatase activity of 0-5 cm and 5-10 cm soil layers significantly increased, and the peak increment was at the vigorous growth stage of rice.

Normal values of the sagittal diameter of the lumbar spine (vertebral body and dural sac) in children measured by MRI

International Nuclear Information System (INIS)

Knirsch, Walter; Kurtz, Claudia; Langer, Mathias; Haeffner, Nicole; Kececioglu, Deniz

2005-01-01

The definition of normal values is a prerequisite for the reliable evaluation of abnormality in the lumbar spine, such as spinal canal stenosis or dural ectasia in patients with Marfan syndrome. Values for vertebral body diameter (VBD) and dural sac diameter (DSD) for the lumbar spine have been published in adults. In children, normal values have been established using conventional radiography or myelography, but not by MRI. To define normal values for the sagittal diameter of the vertebral body and dural sac, and to calculate a dural sac ratio (DSR) in the lumbosacral spine (L1-S1) in healthy children using MRI. A total of 75 healthy children between 6 years and 17 years of age were examined using a sagittal T2-weighted sequence. Sagittal VBD and DSD were measured and a DSR was calculated. This was a retrospective and cross-sectional study. With increasing age there is a significant increase of VBD, a slight increase of DSD, and a slight decrease of DSR. There is no significant sex difference. DSR in healthy children is higher than in healthy adults. MRI is a reliable method demonstrating the natural shape of the lumbosacral spine and its absolute values. These normal values compare well with those established by conventional radiological techniques. Our data may serve as a reference for defining dural ectasia in children with Marfan syndrome. (orig.)

Normal values of the sagittal diameter of the lumbar spine (vertebral body and dural sac) in children measured by MRI

Energy Technology Data Exchange (ETDEWEB)

Knirsch, Walter [University Children' s Hospital Freiburg, Department of Pediatric Cardiology, Freiburg (Germany); University Children' s Hospital Zurich, Division of Paediatric Cardiology, Zurich (Switzerland); Kurtz, Claudia; Langer, Mathias [University Hospital Freiburg, Department of Radiology, Freiburg (Germany); Haeffner, Nicole; Kececioglu, Deniz [University Children' s Hospital Freiburg, Department of Pediatric Cardiology, Freiburg (Germany)

2005-04-01

The definition of normal values is a prerequisite for the reliable evaluation of abnormality in the lumbar spine, such as spinal canal stenosis or dural ectasia in patients with Marfan syndrome. Values for vertebral body diameter (VBD) and dural sac diameter (DSD) for the lumbar spine have been published in adults. In children, normal values have been established using conventional radiography or myelography, but not by MRI. To define normal values for the sagittal diameter of the vertebral body and dural sac, and to calculate a dural sac ratio (DSR) in the lumbosacral spine (L1-S1) in healthy children using MRI. A total of 75 healthy children between 6 years and 17 years of age were examined using a sagittal T2-weighted sequence. Sagittal VBD and DSD were measured and a DSR was calculated. This was a retrospective and cross-sectional study. With increasing age there is a significant increase of VBD, a slight increase of DSD, and a slight decrease of DSR. There is no significant sex difference. DSR in healthy children is higher than in healthy adults. MRI is a reliable method demonstrating the natural shape of the lumbosacral spine and its absolute values. These normal values compare well with those established by conventional radiological techniques. Our data may serve as a reference for defining dural ectasia in children with Marfan syndrome. (orig.)

Dephosphorylation of microtubule-binding sites at the neurofilament-H tail domain by alkaline, acid, and protein phosphatases.

Science.gov (United States)

Hisanaga, S; Yasugawa, S; Yamakawa, T; Miyamoto, E; Ikebe, M; Uchiyama, M; Kishimoto, T

1993-06-01

The dephosphorylation-induced interaction of neurofilaments (NFs) with microtubules (MTs) was investigated by using several phosphatases. Escherichia coli alkaline and wheat germ acid phosphatases increased the electrophoretic mobility of NF-H and NF-M by dephosphorylation, and induced the binding of NF-H to MTs. The binding of NFs to MTs was observed only after the electrophoretic mobility of NF-H approached the exhaustively dephosphorylated level when alkaline phosphatase was used. The number of phosphate remaining when NF-H began to bind to MTs was estimated by measuring phosphate bound to NF-H. NF-H did not bind to MTs even when about 40 phosphates from the total of 51 had been removed by alkaline phosphatase. The removal of 6 further phosphates finally resulted in the association of NF-H with MTs. A similar finding, that the restricted phosphorylation sites in the NF-H tail domain, but not the total amount of phosphates, were important for binding to MTs, was also obtained with acid phosphatases. In contrast to alkaline and acid phosphatases, four classes of protein phosphatases (protein phosphatases 1, 2A, 2B, and 2C) were ineffective for shifting the electrophoretic mobility of NF proteins and for inducing the association of NFs to MTs.

Coupling between the voltage-sensing and phosphatase domains of Ci-VSP.

Science.gov (United States)

Villalba-Galea, Carlos A; Miceli, Francesco; Taglialatela, Maurizio; Bezanilla, Francisco

2009-07-01

The Ciona intestinalis voltage sensor-containing phosphatase (Ci-VSP) shares high homology with the phosphatidylinositol phosphatase enzyme known as PTEN (phosphatase and tensin homologue deleted on chromosome 10). We have taken advantage of the similarity between these proteins to inquire about the coupling between the voltage sensing and the phosphatase domains in Ci-VSP. Recently, it was shown that four basic residues (R11, K13, R14, and R15) in PTEN are critical for its binding onto the membrane, required for its catalytic activity. Ci-VSP has three of the basic residues of PTEN. Here, we show that when R253 and R254 (which are the homologues of R14 and R15 in PTEN) are mutated to alanines in Ci-VSP, phosphatase activity is disrupted, as revealed by a lack of effect on the ionic currents of KCNQ2/3, where current decrease is a measure of phosphatase activity. The enzymatic activity was not rescued by the introduction of lysines, indicating that the binding is an arginine-specific interaction between the phosphatase binding domain and the membrane, presumably through the phosphate groups of the phospholipids. We also found that the kinetics and steady-state voltage dependence of the S4 segment movement are affected when the arginines are not present, indicating that the interaction of R253 and R254 with the membrane, required for the catalytic action of the phosphatase, restricts the movement of the voltage sensor.

Detection of endogenous alkaline phosphatase activity in intact cells by flow cytometry using the fluorogenic ELF-97 phosphatase substrate

Science.gov (United States)

Telford, W. G.; Cox, W. G.; Stiner, D.; Singer, V. L.; Doty, S. B.

1999-01-01

BACKGROUND: The alkaline phosphatase (AP) substrate 2-(5'-chloro-2'-phosphoryloxyphenyl)-6-chloro-4-(3H)-quinazolinone (ELF((R))-97 for enzyme-labeled fluorescence) has been found useful for the histochemical detection of endogenous AP activity and AP-tagged proteins and oligonucleotide probes. In this study, we evaluated its effectiveness at detecting endogenous AP activity by flow cytometry. METHODS: The ELF-97 phosphatase substrate was used to detect endogenous AP activity in UMR-106 rat osteosarcoma cells and primary cultures of chick chondrocytes. Cells were labeled with the ELF-97 reagent and analyzed by flow cytometry using an argon ultraviolet (UV) laser. For comparison purposes, cells were also assayed for AP using a Fast Red Violet LB azo dye assay previously described for use in detecting AP activity by flow cytometry. RESULTS: The ELF-97 phosphatase substrate effectively detected endogenous AP activity in UMR-106 cells, with over 95% of the resulting fluorescent signal resulting from AP-specific activity (as determined by levamisole inhibition of AP activity). In contrast, less than 70% of the fluorescent signal from the Fast Red Violet LB (FRV) assay was AP-dependent, reflecting the high intrinsic fluorescence of the unreacted components. The ELF-97 phosphatase assay was also able to detect very low AP activity in chick chondrocytes that was undetectable by the azo dye method. CONCLUSIONS: The ELF-97 phosphatase assay was able to detect endogenous AP activity in fixed mammalian and avian cells by flow cytometry with superior sensitivity to previously described assays. This work also shows the applicability of ELF-97 to flow cytometry, supplementing its previously demonstrated histochemical applications. Copyright 1999 Wiley-Liss, Inc.

Yolk sac mesenchymal progenitor cells from New World mice (Necromys lasiurus with multipotent differential potential.

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Phelipe Oliveira Favaron

Full Text Available Fetal membranes are abundant, ethically acceptable and readily accessible sources of stem cells. In particular, the yolk sac is a source of cell lineages that do not express MHCs and are mainly free from immunological incompatibles when transferred to a recipient. Although data are available especially for hematopoietic stem cells in mice and human, whereas other cell types and species are dramatically underrepresented. Here we studied the nature and differentiation potential of yolk sac derived mesenchymal stem cells from a New World mouse, Necromys lasiurus. Explants from mid-gestation were cultured in DMEM-High glucose medium with 10% defined fetal bovine serum. The cells were characterized by standard methods including immunophenotyping by fluorescence and flow cytometry, growth and differentiation potential and tumorigenicity assays. The first adherent cells were observed after 7 days of cell culture and included small, elongated fibroblast-like cells (92.13% and large, round epithelial-like cells with centrally located nuclei (6.5%. Only the fibroblast-like cells survived the first passages. They were positive to markers for mesenchymal stem cells (Stro-1, CD90, CD105, CD73 and pluripotency (Oct3/4, Nanog as well as precursors of hematopoietic stem cells (CD117. In differentiation assays, they were classified as a multipotent lineage, because they differentiated into osteogenic, adipogenic, and chondrogenic lineages and, finally, they did not develop tumors. In conclusion, mesenchymal progenitor cells with multipotent differentiation potential and sufficient growth and proliferation abilities were able to be obtained from Necromys yolk sacs, therefore, we inferred that these cells may be promising for a wide range of applications in regenerative medicine.

The Drosophila DOCK family protein Sponge is required for development of the air sac primordium

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Morishita, Kazushge; Anh Suong, Dang Ngoc; Yoshida, Hideki; Yamaguchi, Masamitsu, E-mail: myamaguc@kit.ac.jp

2017-05-15

Dedicator of cytokinesis (DOCK) family genes are known as DOCK1-DOCK11 in mammals. DOCK family proteins mainly regulate actin filament polymerization and/or depolymerization and are GEF proteins, which contribute to cellular signaling events by activating small G proteins. Sponge (Spg) is a Drosophila counterpart to mammalian DOCK3/DOCK4, and plays a role in embryonic central nervous system development, R7 photoreceptor cell differentiation, and adult thorax development. In order to conduct further functional analyses on Spg in vivo, we examined its localization in third instar larval wing imaginal discs. Immunostaining with purified anti-Spg IgG revealed that Spg mainly localized in the air sac primordium (ASP) in wing imaginal discs. Spg is therefore predicted to play an important role in the ASP. The specific knockdown of Spg by the breathless-GAL4 driver in tracheal cells induced lethality accompanied with a defect in ASP development and the induction of apoptosis. The monitoring of ERK signaling activity in wing imaginal discs by immunostaining with anti-diphospho-ERK IgG revealed reductions in the ERK signal cascade in Spg knockdown clones. Furthermore, the overexpression of D-raf suppressed defects in survival and the proliferation of cells in the ASP induced by the knockdown of Spg. Collectively, these results indicate that Spg plays a critical role in ASP development and tracheal cell viability that is mediated by the ERK signaling pathway. - Highlights: • Spg mainly localizes in the air sac primordium in wing imaginal discs. • Spg plays a critical role in air sac primordium development. • Spg positively regulates the ERK signal cascade.

A generally applicable sequential alkaline phosphatase immunohistochemical double staining

NARCIS (Netherlands)

van der Loos, Chris M.; Teeling, Peter

2008-01-01

A universal type of sequential double alkaline phosphatase immunohistochemical staining is described that can be used for formalin-fixed, paraffin-embedded and cryostat tissue sections from human and mouse origin. It consists of two alkaline phosphatase detection systems including enzymatic

Interaction of Protein Phosphatase 1δ with Nucleophosmin in Human Osteoblastic Cells

International Nuclear Information System (INIS)

Haneji, Tatsuji; Teramachi, Jumpei; Hirashima, Kanji; Kimura, Koji; Morimoto, Hiroyuki

2012-01-01

Protein phosphorylation and dephosphorylation has been recognized as an essential mechanism in the regulation of cellular metabolism and function in various tissues. Serine and threonine protein phosphatases (PP) are divided into four categories: PP1, PP2A, PP2B, and PP2C. At least four isoforms of PP1 catalytic subunit in rat, PP1α, PP1γ1, PP1γ2, and PP1δ, were isolated. In the present study, we examined the localization and expression of PP1δ in human osteoblastic Saos-2 cells. Anti-PP1δ antibody recognized a protein present in the nucleolar regions in Saos-2 cells. Cellular fractionation revealed that PP1δ is a 37 kDa protein localized in the nucleolus. Nucleophosmin is a nucleolar phosphoprotein and located mainly in the nucleolus. Staining pattern of nucleophosmin in Saos-2 cells was similar to that of PP1δ. PP1δ and nucleophosmin were specifically stained as dots in the nucleus. Dual fluorescence images revealed that PP1δ and nucleophosmin were localized in the same regions in the nucleolus. Similar distribution patterns of PP1δ and nucleophosmin were observed in osteoblastic MG63 cells. The interaction of PP1δ and nucleophosmin was also shown by immunoprecipitation and Western analysis. These results indicated that PP1δ associate with nucleophosmin directly in the nucleolus and suggested that nucleophosmin is one of the candidate substrate for PP1δ

Characterizing the interactions between prolyl isomerase pin1 and phosphatase inhibitor-2 in living cells with FRET and FCS

Science.gov (United States)

Sun, Yuansheng; Wang, Lifu; Jyothikumar, Vinod; Brautigan, David L.; Periasamy, Ammasi

2012-03-01

Phosphatase inhibitor-2 (I2) was discovered as a regulator of protein Ser/Thr phosphatase-1 and is conserved from yeast to human. Binding between purified recombinant I2 from different species and the prolyl isomerase Pin1 has been demonstrated with pull-down assays, size exclusion chromatography and nuclear magnetic resonance spectroscopy. Despite this, questions persist as to whether these proteins associate together in living cells. In this study, we prepared fluorescent protein (FP) fusions of I2 and Pin1 and employed both Förster Resonance Energy Transfer (FRET) and Fluorescence Correlation Spectroscopy (FCS) imaging techniques to characterize their interactions in living cells. In both intensity-based and time-resolved FRET studies, we observed FRET uniformly across whole cells co-expressing I2-Cerulean and Pin1-Venus that was significantly higher than in negative controls expressing Cerulean FP (without fusing to I2) as the FRET donor and Pin1-Venus, showing a specific interaction between I2-Cerulean and Pin1-Venus in living cells. We also observed the co-diffusion of I2-Cerulean and Pin1-mCherry in Fluorescence Cross Correlation Spectroscopy (FCCS) measurements. We further showed that I2 itself as well as I2-Pin1 formed complexes in living cells (predicted from in vitro studies) via a quantitative FRET assay, and demonstrated from FCS measurements that both I2 and Pin1 (fused to Cerulean) are highly mobile in living cells.

Microwave induced stimulation of /sup 32/Pi incorporation into phosphoinositides of rat brain synaptosomes

Energy Technology Data Exchange (ETDEWEB)

Gandhi, C.R.; Ross, D.H.

1989-07-01

Exposure of synaptosomes to microwave radiation at a power density of 10 mW/sq cm or more produced stimulation of the /sup 32/Pi-incorporation into phosphoinositides. The extent of /sup 32/Pi incorporation was found to be much more pronounced in phosphatidylinositol-4-phosphate (PIP), and phosphatidylinositol-4,5-bisphosphate (PIP/sub 2/) as compared to phosphatidylinositol (PI) and phosphatidic acid (PA). Other lipids were also found to incorporate /sup 32/Pi but no significant changes in their labeling were seen after exposure to microwave radiation. Inclusion of 10 mM lithium in the medium reduced the basal labeling of PIP/sub 2/, PIP and PI and increased PA labeling. Li/sup +/ also inhibited the microwave stimulated PIP/sub 2/, PIP and PI labeling but had no effect on PA labeling. Calcium inophore, A/sub 23187/, inhibited the basal and microwave stimulated /sup 32/Pi labeling of PIP and PIP/sub 2/, stimulated basal labeling of PA and PI and had no effect on microwave stimulated PA and PI labeling. Calcium chelator, EGTA, on the other hand, had no effect on basal labeling of PA and PI, stimulated basal PIP and PIP/sub 2/ labeling but did not alter microwave stimulated labeling of these lipids. Exposure of synaptosomes to microwave radiation did not alter the chemical concentration of phosphoinositides indicating that the turnover of these lipids was altered. These results suggest that low frequency microwave radiation alter the metabolism of inositol phospholipids by enhancing their turnover and thus may affect the transmembrane signalling in the nerve endings.

Human liver phosphatase 2A: cDNA and amino acid sequence of two catalytic subunit isotypes

International Nuclear Information System (INIS)

Arino, J.; Woon, Chee Wai; Brautigan, D.L.; Miller, T.B. Jr.; Johnson, G.L.

1988-01-01

Two cDNA clones were isolated from a human liver library that encode two phosphatase 2A catalytic subunits. The two cDNAs differed in eight amino acids (97% identity) with three nonconservative substitutions. All of the amino acid substitutions were clustered in the amino-terminal domain of the protein. Amino acid sequence of one human liver clone (HL-14) was identical to the rabbit skeletal muscle phosphatase 2A cDNA (with 97% nucleotide identity). The second human liver clone (HL-1) is encoded by a separate gene, and RNA gel blot analysis indicates that both mRNAs are expressed similarly in several human clonal cell lines. Sequence comparison with phosphatase 1 and 2A indicates highly divergent amino acid sequences at the amino and carboxyl termini of the proteins and identifies six highly conserved regions between the two proteins that are predicted to be important for phosphatase enzymatic activity

Enzymatic exchange of sulphur between cysteine and hydrogen sulphide in the yolk sac of an incubated bird's egg; Echange enzymatique entre le soufre de la cysteine et celui de l'hydrogene sulfure dans le sac vitellin de l'oeuf embryonne d'oiseau

Energy Technology Data Exchange (ETDEWEB)

Chapeville, F; Fromageot, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

Previous work has shown that the formation of cysteic acid from sulphate in incubated hen's eggs is due to the following reactions: a) reduction of sulphate to sulphite by the yolk sac endoderm cells; b) synthesis of cysteic acid from the sulphite in the presence of cysteine with liberation of hydrogen sulphide: HS-CH{sub 2}-CH(NH{sub 2})-COOH + SO{sub 3}H{sup -} {yields} H{sub 2}S + {sup -}O{sub 3}S-CH{sub 2}-CH(NH{sub 2})-COOH (1). The enzymatic system responsible for this reaction is localized on the yolk sac endoderm and in the yolk. It may be wondered whether reaction (1) is not made up of two consecutive reactions, one of which is reversible: HS-CH{sub 2}-CH(NH{sub 2})-COOH {r_reversible} H{sub 2}S + organic chain (2) and organic chain + SO{sub 3}H{sup -} {yields} {sup -}O{sub 3}S-CH{sub 2}-CH(NH{sub 2})-COOH (3). It would then be clear why the addition of sulphite displaces the equilibrium towards the production of cysteic acid and hydrogen sulphide. If this is the case, the addition of ordinary cysteine and of marked hydrogen sulphide to the biological medium should make it possible to detect the formation of {sup 35}S cysteine. The present work shows that the desulphurization of the cysteine (reaction 2) by the yolk sac + the yolk is in fact a reversible reaction, and that an enzymatic exchange occurs between the sulphur of the cysteine and that of the hydrogen sulphide. (author) [French] Un precedent travail a montre que la formation de l'acide cysteique a partir de sulfate dans l'oeuf embryonne de poule correspond aux reactions suivantes: a) Reduction du sulfate en sulfite par les cellules de l'endoderme du sac vitellin; b) synthese de l'acide cysteique a partir du sulfite en presence de cysteine avec liberation de l'hydrogene sulfure: HS-CH{sub 2}-CH(NH{sub 2})-COOH + SO{sub 3}H{sup -} {yields} H{sub 2}S + {sup -}O{sub 3}S-CH{sub 2}-CH(NH{sub 2})-COOH (1). Le systeme enzymatique responsable de cette reaction est localise dans l'endoderme du sac vitellin

Molecular dynamics simulations of protein-tyrosine phosphatase 1B: II. Substrate-enzyme interactions and dynamics

DEFF Research Database (Denmark)

Peters, Günther H.j.; Frimurer, T. M.; Andersen, J. N.

2000-01-01

Molecular dynamics simulations of protein tyrosine phosphatase 1B (PTP1B) complexed with the phosphorylated peptide substrate DADEpYL and the free substrate have been conducted to investigate 1) the physical forces involved in substrate-protein interactions, 2) the importance of enzyme...... to substrate binding. Based on essential dynamics analysis of the PTP1B/DADEpYL trajectory, it is shown that internal motions in the binding pocket occur in a subspace of only a few degrees of freedom. in particular, relatively large flexibilities are observed along several eigenvectors in the segments: Arg(24...... for catalysis. Analysis of the individual enzyme-substrate interaction energies revealed that mainly electrostatic forces contribute to binding. Indeed, calculation of the electrostatic field of the enzyme reveals that only the field surrounding the binding pocket is positive, while the remaining protein...

Acid phosphatases in seeds and developing of squash (Cucurbita ficifolia

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Irena Lorenc-Kubis

2014-01-01

Full Text Available Changes in protein content and acid phosphatase activity were followed during germination (imbition through seedlings development in extracts from cotyledons of squash (Cucurbita ficifolia. It has been shown that the activity of acid phosphatase was initially low and than increased to a maximum after 6 days of imbition. Acid phosphates were isolated from cotyledons of seeds and from 6-, 10- and 22-days old seedlings by extraction the proteins with 0.1 M acetate buffer pH 5.1, precipitation with ethanol and by affinity chromatography on con A-Sepharose. Two glycoprotein enzymes AcPase Ba and AcPase Bb which differ in their affinity to immobilized con A were obtained. Both acid phosphatates retained the enzyme activity after binding to free con A. Rocket affinity electrophoresis of AcPase Ba and AcPase Bb, isolated from cotyledons of seeds and seedlings, revealed differences in their ability to bind to con A during seeds germination and seedling develop-ment indicating changes in their sugar component. Con A was found to activate both enzymes. The enzymes cross-reacted with monospecific antibodies raised against grass seed acid phosphatate Ba indicating an antigenic relationship between squash and grass acid phosphatases.

Combination of PKCε Activation and PTP1B Inhibition Effectively Suppresses Aβ-Induced GSK-3β Activation and Tau Phosphorylation.

Science.gov (United States)

Kanno, Takeshi; Tsuchiya, Ayako; Tanaka, Akito; Nishizaki, Tomoyuki

2016-09-01

Glycogen synthase kinase-3β (GSK-3β) is a key element to phosphorylate tau and form neurofibrillary tangles (NFTs) found in tauopathies including Alzheimer's disease (AD). A current topic for AD therapy is focused upon how to prevent tau phosphorylation. In the present study, PKCε activated Akt and inactivated GSK-3β by directly interacting with each protein. Inhibition of protein tyrosine phosphatase 1B (PTP1B), alternatively, caused an enhancement in the tyrosine phosphorylation of insulin receptor substrate 1 (IRS-1), allowing activation of Akt through a pathway along an IRS-1/phosphatidylinositol 3 kinase (PI3K)/3-phosphoinositide-dependent protein kinase-1 (PDK1)/Akt axis, to phosphorylate and inactivate GSK-3β. Combination of PKCε activation and PTP1B inhibition more sufficiently activated Akt and inactivated GSK-3β than each independent treatment, to suppress amyloid β (Aβ)-induced tau phosphorylation and ameliorate spatial learning and memory impairment in 5xFAD transgenic mice, an animal model of AD. This may represent an innovative strategy for AD therapy.

Contribution to the study of the reduction of sulfate by the yolk sac of the chicken embryo; Contribution a l'etude de la reduction du sulfate par le sac vitellin de l'embryon de poulet

Energy Technology Data Exchange (ETDEWEB)

Bourgeois, Claude

1958-11-15

This academic reports addresses additional information obtained about the reduction of sulfate into sulphite by the yolk sac of a chicken embryo. Two important difficulties have been faced: the impossibility to isolate this reduction from reactions which immediately use the formed sulphite, and the impossibility to obtain an acellular preparation able to reduce the sulfate. Then, the problem of reduction of sulfate into sulphite by the yolk sac is associated with the problem of permeability of yolk sac cells to the studied substances. Thus, the author studied whether other animal species could provide a better material than the chicken embryo for this study of sulfate reduction. It appears that some vertebrate embryos present some evidence of sulphur metabolism similar to that of chicken embryo. However, this last one revealed to be the most favourable for the study. The author reports the study of the evolution of the reduction activity of the yolk sac sulfate with respect to the embryo age, and the effect of some metabolic inhibitors on this activity [French] Dans le present travail nous avons obtenu quelques renseignements concernant la reduction du sulfate en sulfite par l'embryon de poulet. Cette etude a ete menee, a l'aide de substances marquees par le soufre {sup 35}S, par les methodes qui avaient permis anterieurement a Chapeville et Fromageot de mettre en evidence cette reaction et les reactions qui lui font suite au cours de la synthese des aminoacides soufres. Pour apprecier la reduction du sulfate {sup 35}S, nous avons mesure la quantite d'acide cysteique {sup 35}S et de taurine {sup 35}S formes a partir du sulfite {sup 35}S. Appliquant ces techniques aux embryons d'especes animales variees, nous avons constate que quelques embryons de vertebres etaient capables d'utiliser le sulfite a la synthese d'acide cysteique: les embryons de roussette et de rat avec un rendement faible, l'embryon d'un passereau de la famille des turdides, comme celui du poulet

Vanadate monomers and dimers both inhibit the human prostatic acid phosphatase.

Science.gov (United States)

Crans, D C; Simone, C M; Saha, A K; Glew, R H

1989-11-30

A combination of enzyme kinetics and 51V NMR spectroscopy was used to identify the species of vanadate that inhibits acid phosphatases. Monomeric vanadate was shown to inhibit wheat germ and potato acid phosphatases. At pH 5.5, the vanadate dimer inhibits the human prostatic acid phosphatase whereas at pH 7.0 it is the vanadate monomer that inhibits this enzyme. The pH-dependent shift in the affinity of the prostatic phosphatase for vanadate is presumably due to deprotonation of an amino acid side chain in or near the binding site resulting in a conformational change in the protein. pH may be a subtle effector of the insulin-like vanadate activity in biological systems and may explain some of the differences in selectivity observed with the protein phosphatases.

Comparative Genomics of Pneumocystis Species Suggests the Absence of Genes for myo-Inositol Synthesis and Reliance on Inositol Transport and Metabolism

Science.gov (United States)

Sesterhenn, Thomas M.; Collins, Margaret S.; Welge, Jeffrey A.

2014-01-01

ABSTRACT In the context of deciphering the metabolic strategies of the obligate pathogenic fungi in the genus Pneumocystis, the genomes of three species (P. carinii, P. murina, and P. jirovecii) were compared among themselves and with the free-living, phylogenetically related fission yeast (Schizosaccharomyces pombe). The underrepresentation of amino acid metabolism pathways compared to those in S. pombe, as well as the incomplete steroid biosynthesis pathway, were confirmed for P. carinii and P. jirovecii and extended to P. murina. All three Pneumocystis species showed overrepresentation of the inositol phosphate metabolism pathway compared to that in the fission yeast. In addition to those known in S. pombe, four genes, encoding inositol-polyphosphate multikinase (EC 2.7.1.151), inositol-pentakisphosphate 2-kinase (EC 2.7.1.158), phosphoinositide 5-phosphatase (EC 3.1.3.36), and inositol-1,4-bisphosphate 1-phosphatase (EC 3.1.3.57), were identified in the two rodent Pneumocystis genomes, P. carinii and P. murina. The P. jirovecii genome appeared to contain three of these genes but lacked phosphoinositide 5-phosphatase. Notably, two genes encoding enzymes essential for myo-inositol synthesis, inositol-1-phosphate synthase (INO1) and inositol monophosphatase (INM1), were absent from all three genomes, suggesting that Pneumocystis species are inositol auxotrophs. In keeping with the need to acquire exogenous inositol, two genes with products homologous to fungal inositol transporters, ITR1 and ITR2, were identified in P. carinii and P. murina, while P. jirovecii contained only the ITR1 homolog. The ITR and inositol metabolism genes in P. murina and P. carinii were expressed during fulminant infection as determined by reverse transcriptase real-time PCR of cDNA from infected lung tissue. Supplementation of in vitro culture with inositol yielded significant improvement of the viability of P. carinii for days 7 through 14. PMID:25370490

The impact of phosphatases on proliferative and survival signaling in cancer.

Science.gov (United States)

Narla, Goutham; Sangodkar, Jaya; Ryder, Christopher B

2018-05-03

The dynamic and stringent coordination of kinase and phosphatase activity controls a myriad of physiologic processes. Aberrations that disrupt the balance of this interplay represent the basis of numerous diseases. For a variety of reasons, early work in this area portrayed kinases as the dominant actors in these signaling events with phosphatases playing a secondary role. In oncology, these efforts led to breakthroughs that have dramatically altered the course of certain diseases and directed vast resources toward the development of additional kinase-targeted therapies. Yet, more recent scientific efforts have demonstrated a prominent and sometimes driving role for phosphatases across numerous malignancies. This maturation of the phosphatase field has brought with it the promise of further therapeutic advances in the field of oncology. In this review, we discuss the role of phosphatases in the regulation of cellular proliferation and survival signaling using the examples of the MAPK and PI3K/AKT pathways, c-Myc and the apoptosis machinery. Emphasis is placed on instances where these signaling networks are perturbed by dysregulation of specific phosphatases to favor growth and persistence of human cancer.

Clinical effects of conjunctival sac flushing using different concentration of povidoneiodine on corneal epithelium before cataract surgeries

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Xue-Lian Gu

2015-10-01

Full Text Available AIM:To determine the most optimal concentration of the safe usage of povidone-iodine(PVP-Iin the flushing to disinfect the conjunctive sac before cataract surgeries, in order to provide a scientific basis for clinical eye surgery work.METHODS:Sixty-two patients with phacoemulsification and intraocular lens implantation in our hospital from October 2012 to October 2014 were randomly divided into 0.25g/L PVP-I group(Ⅰand 5g/L PVP-I group(Ⅱ. Sterilizing effect and the complications postoperative were analyzed.RESULTS:The sterilizing effects of the two groups after flushing conjunctiva sac using different concentrations of PVP-I were both remarkable, but the difference between the two groups was not statistically significant(P>0.05. No endophthalmitis occurred in the two groups. Observing the corneal condition after rinsing, no severe conjunctival hyperemia, corneal edema and other serious complications occurred. There was slightly punctate corneal epithelial shedding in groupⅡ, and the difference was statistically significant(PPCONCLUSION:Using 0.25g/L PVP-I in the conjunctiva sac rinsing before surgeries can inhibit the growth of bacteria in the conjunctival sac, reduce the impact on the corneal epithelium thereby reducing the incidence of postoperative complications and the positive rate of bacterial culture, increasing the comfort degree of patients, bringing a better area for the surgeries.

Phosphoprotein phosphatase of bovine spleen cell nuclei: physicochemical properties

International Nuclear Information System (INIS)

Rezyapkin, V.I.; Leonova, L.E.; Komkova, A.I.

1986-01-01

The physicochemical properties of phosphoprotein phosphatase (EC 1.3.1.16) from bovine spleen cell nuclei were studied. The enzyme possesses broad substrate specificity and catalyzes the dephosphorylation of phosphocasein, ATP, ADP, and p-nitrophenyl phosphate (pNPP). K/sub m/ for ATP, ADP, and pNPP are equal to 0.44, 0.43, and 1.25 mM, respectively. M/sub r/ of the enzyme, according to the data of gel filtraction of Sephadex G-75 and electrophoresis in polyacrylamide gel of various concentrations is ∼ 33,000. In electrophoresis in the presence of SDS, two protein bands with M/sub r/ 12,000 and 18,000 are detected. In the enzyme molecule, acid amino acid residues predominate; two free SH groups and two disulfide bridges are detected. Phosphoprotein phosphatase is a glycoprotein, containing ∼ 22% carbonhydrates. The protein possesses a supplementary absorption maximum at 560 nm. Ammonium molybdate is a competitive inhibitor with K/sub i/ 0.37 μM, while sodium fluoride is a noncompetitive inhibitor with K/sub i/ 1.3 mM. Incubation in the presence of 2 mM phenylmethylsulfonyl fluoride for 25 h leads to a loss of ∼ 46% of the enzymatic activity. Ammonium molybdate, sodium fluoride, and PMSF are reversible inhibitors. Modifications of the SH groups, NH 2 groups, and histidine leads to a decrease in the enzymatic activity. Incubation of phosphoprotein phosphatase with [γ- 32 P]ATP leads to the incorporation of 0.33 mole 33 P per mole of the enzyme. The mechanism of hydrolysis of the phosphodiester bond, catalyzed by the enzyme, is discussed

Effecf of pH and some cations on activity of acid phosphatase secreted from Ustilago sp. isolated from acid sulphate soil

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Chairatana Nilnond

2007-03-01

Full Text Available Acid phosphatase secreted from Ustilago sp. is able to hydrolyze organic phosphorus. These soil yeast microorganisms were isolated from rice roots grown in acid sulphate soil that generally contains highamount of aluminum (Al, iron (Fe and manganese (Mn ions. Therefore, the objectives of this study were to examine the effect of pH and some cations on acid phosphatase activity. Two isolates of Ustilago sp., AR101and AR102, were cultured in 100 mL of modified Pikovskaya's broth containing Na-phytate, pH 4, and acid phosphatase activity was determined at pH 2.0-7.0. Effect of Al, Fe, and Mn, including calcium (Ca ions,on growth of AR101 and AR102, secreted acid phosphatase activity, and the ability of acid phosphatase on the phosphorus release from Na-phytate by Ustilago sp. were investigated. It was found that the optimum pH for acid phosphatase activity was 3.5-4.5. The activity of acid phosphatase secreted from AR101 (3,690nmol min-1 mL-1 was remarkably higher than that from AR102 (956 nmol min-1 mL-1. Aluminum, iron, manganese and calcium ions in the medium did not affect the growth of either isolate. The activity of secretedacid phosphatase of AR101 was inhibited by Al and Ca ion, and synthesis of acid phosphatase of Ustilago sp. AR102 was possibly stimulated by Fe ion. Both AR101 and AR102 solubilized Na-phytate, resulting in therelease of P. However, some amount of released P was then precipitated with Al and Fe ions as the highly insoluble Fe- or Al- phosphate.

Phosphorylation-mediated regulation of the Staphylococcus aureus secreted tyrosine phosphatase PtpA.

Science.gov (United States)

Brelle, Solène; Baronian, Grégory; Huc-Brandt, Sylvaine; Zaki, Laila Gannoun; Cohen-Gonsaud, Martin; Bischoff, Markus; Molle, Virginie

2016-01-15

Due to the emergence of methicillin-resistant strains, Staphylococcus aureus has become as major public-health threat. Studies aimed at deciphering the molecular mechanism of virulence are thus required to identify new targets and develop efficient therapeutic agents. Protein phosphorylations are known to play key regulatory functions and their roles in pathogenesis are under intense scrutiny. Here we analyzed the protein tyrosine phosphatase PtpA of S. aureus, a member of the family of low molecular weight protein tyrosine phosphatases that are often secreted by pathogenic bacteria. We report for the first time that PtpA is phosphorylated in vitro by the S. aureus tyrosine kinase CapA1B2. A mass spectrometry approach allowed determining that Tyr122 and Tyr123 were the only two residues phosphorylated by this kinase. This result was confirmed by analysis of a double PtpA_Y122A/Y123A mutant that showed no phosphorylation by CapA1B2. Interestingly, PtpA phosphatase activity was abrogated in this mutant, suggesting a key regulatory function for these two tyrosine residues. This was further reinforced by the observation that CapA1B2-mediated phosphorylation significantly increased PtpA phosphatase activity. Moreover, we provide evidence that PtpA is secreted during growth of S. aureus. Together our results suggest that PtpA is an exported S. aureus signaling molecule controlled by tyrosine phosphorylation which may interfere with host cell signaling. Copyright © 2015 Elsevier Inc. All rights reserved.

Nuclear Envelope Phosphatase 1-Regulatory Subunit 1 (Formerly TMEM188) Is the Metazoan Spo7p Ortholog and Functions in the Lipin Activation Pathway*

Science.gov (United States)

Han, Sungwon; Bahmanyar, Shirin; Zhang, Peixiang; Grishin, Nick; Oegema, Karen; Crooke, Roseann; Graham, Mark; Reue, Karen; Dixon, Jack E.; Goodman, Joel M.

2012-01-01

Lipin-1 catalyzes the formation of diacylglycerol from phosphatidic acid. Lipin-1 mutations cause lipodystrophy in mice and acute myopathy in humans. It is heavily phosphorylated, and the yeast ortholog Pah1p becomes membrane-associated and active upon dephosphorylation by the Nem1p-Spo7p membrane complex. A mammalian ortholog of Nem1p is the C-terminal domain nuclear envelope phosphatase 1 (CTDNEP1, formerly “dullard”), but its Spo7p-like partner is unknown, and the need for its existence is debated. Here, we identify the metazoan ortholog of Spo7p, TMEM188, renamed nuclear envelope phosphatase 1-regulatory subunit 1 (NEP1-R1). CTDNEP1 and NEP1-R1 together complement a nem1Δspo7Δ strain to block endoplasmic reticulum proliferation and restore triacylglycerol levels and lipid droplet number. The two human orthologs are in a complex in cells, and the amount of CTDNEP1 is increased in the presence of NEP1-R1. In the Caenorhabditis elegans embryo, expression of nematode CTDNEP1 and NEP1-R1, as well as lipin-1, is required for normal nuclear membrane breakdown after zygote formation. The expression pattern of NEP1-R1 and CTDNEP1 in human and mouse tissues closely mirrors that of lipin-1. CTDNEP1 can dephosphorylate lipins-1a, -1b, and -2 in human cells only in the presence of NEP1-R1. The nuclear fraction of lipin-1b is increased when CTDNEP1 and NEP1-R1 are co-expressed. Therefore, NEP1-R1 is functionally conserved from yeast to humans and functions in the lipin activation pathway. PMID:22134922

Control of Acid Phosphatases Expression from Aspergillus niger by Soil Characteristics

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Ely Nahas

2015-10-01

Full Text Available ABSTRACTThis work studied the acid phosphatase (APase activity from culture medium (extracellular, eAPase and mycelial extract (intracellular, iAPase ofAspergillus niger F111. The influence of fungus growth and phosphate concentration of the media on the synthesis and secretion of phosphatase was demonstrated. The effects of pH, substrate concentration and inorganic and organic compounds added to the reaction mixture on APase activity were also studied. Both enzymes were repressed by high concentrations of phosphate. Overexpression of iAPase in relation to eAPase was detected; iAPase activity was 46.1 times higher than eAPase. The maximal activity of eAPase was after 24h of fungus growth and for iAPase was after 96h. Optimal pH and substrate concentrations were 4.5 and 8.0 mM, respectively. Michaelis-Menten constant (Km for the hydrolysis of p-nitrophenyl phosphate was 0.57 mM with Vmax = 14,285.71 U mg-1 mycelium for the iAPase and 0.31 mM with V max = 147.06 U mg-1 mycelium for eAPase. Organic substances had little effect on acid phosphatases when compared with the salts. Both the APases were inhibited by 10 mM KH 2PO4 and 5 mM (NH42MoO4; eAPase was also inhibited by 1 mM CoCl2.

Crystallization and preliminary X-ray diffraction analysis of rat protein tyrosine phosphatase η

Energy Technology Data Exchange (ETDEWEB)

Matozo, Huita C.; Nascimento, Alessandro S.; Santos, Maria A. M. [Instituto de Física de São Carlos, Departamento de Física e Informática, Universidade de São Paulo, Avenida Trabalhador São Carlense 400, CEP 13566-590 São Carlos, SP (Brazil); Iuliano, Rodolfo [Dipartimento di Medicina Sperimentale e Clinica, Facoltà di Medicina e Chirurgia, Università di Catanzaro, 88100 Catanzaro (Italy); Fusco, Alfredo [Dipartimento di Biologia e Patologia Cellulare e Molecolare, c/o Instituto di Endocrinologia ed Oncologia Sperimentale del CNR, Facolta di Medicina e Chirurgia, Università degli Studi di Napoli ‘Federico II’, Via Pansini 5, 80131 Naples (Italy); NOGEC (Naples Oncogenomocs Center)-CEINGE, Biotecnologie Avanzate, Via Comunale Margherita 482, 80145 Naples (Italy); Polikarpov, Igor, E-mail: ipolikarpov@if.sc.usp.br [Instituto de Física de São Carlos, Departamento de Física e Informática, Universidade de São Paulo, Avenida Trabalhador São Carlense 400, CEP 13566-590 São Carlos, SP (Brazil); Laboratório Nacional de Luz Síncrotron, Campinas, SP (Brazil)

2006-09-01

In this study, the catalytic domain of rat protein tyrosine phosphatase η was produced in Escherichia coli in soluble form and purified to homogeneity. Crystals were obtained by the hanging-drop vapour-diffusion method. The rat protein tyrosine phosphatase η (rPTPη) is a cysteine-dependent phosphatase which hydrolyzes phosphoester bonds in proteins and other molecules. rPTPη and its human homologue DEP-1 are involved in neoplastic transformations. Thus, expression of the protein is reduced in all oncogene-transformed thyroid cell lines and is absent in highly malignant thyroid cells. Moreover, consistent with the suggested tumour suppression role of PTPη, inhibition of the tumorigenic process occurs after its exogenous reconstitution, suggesting that PTPη might be important for gene therapy of cancers. In this study, the catalytic domain of rPTPη was produced in Escherichia coli in soluble form and purified to homogeneity. Crystals were obtained by the hanging-drop vapour-diffusion method. Diffraction data were collected to 1.87 Å resolution. The crystal belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 46.46, b = 63.07, c = 111.64 Å, and contains one molecule per asymmetric unit.

Crystallization and preliminary X-ray diffraction analysis of rat protein tyrosine phosphatase η

International Nuclear Information System (INIS)

Matozo, Huita C.; Nascimento, Alessandro S.; Santos, Maria A. M.; Iuliano, Rodolfo; Fusco, Alfredo; Polikarpov, Igor

2006-01-01

In this study, the catalytic domain of rat protein tyrosine phosphatase η was produced in Escherichia coli in soluble form and purified to homogeneity. Crystals were obtained by the hanging-drop vapour-diffusion method. The rat protein tyrosine phosphatase η (rPTPη) is a cysteine-dependent phosphatase which hydrolyzes phosphoester bonds in proteins and other molecules. rPTPη and its human homologue DEP-1 are involved in neoplastic transformations. Thus, expression of the protein is reduced in all oncogene-transformed thyroid cell lines and is absent in highly malignant thyroid cells. Moreover, consistent with the suggested tumour suppression role of PTPη, inhibition of the tumorigenic process occurs after its exogenous reconstitution, suggesting that PTPη might be important for gene therapy of cancers. In this study, the catalytic domain of rPTPη was produced in Escherichia coli in soluble form and purified to homogeneity. Crystals were obtained by the hanging-drop vapour-diffusion method. Diffraction data were collected to 1.87 Å resolution. The crystal belongs to space group P2 1 2 1 2 1 , with unit-cell parameters a = 46.46, b = 63.07, c = 111.64 Å, and contains one molecule per asymmetric unit

Somatic cell count and alkaline phosphatase activity in milk for evaluation of mastitis in buffalo

Science.gov (United States)

Patil, M. P.; Nagvekar, A. S.; Ingole, S. D.; Bharucha, S. V.; Palve, V. T.

2015-01-01

Background and Aim: Mastitis is a serious disease of dairy animals causing great economic losses due to a reduction in milk yield as well as lowering its nutritive value. The application of somatic cell count (SCC) and alkaline phosphatase activity in the milk for diagnosis of mastitis in buffalo is not well documented. Therefore, the present study was conducted to observe the SCC and alkaline phosphatase activity for evaluation of mastitis in buffalo. Materials and Methods: Milk samples of forty apparently healthy lactating buffaloes were selected and categorized into five different groups viz. normal buffaloes, buffaloes with subclinical mastitis with CMT positive milk samples (+1 Grade), (+2 Grade), (+3 Grade), and buffaloes with clinical mastitis with 8 animals in each group. The milk samples were analyzed for SCC and alkaline phosphatase activity. Results: The levels of SCC (×105 cells/ml) and alkaline phosphatase (U/L) in different groups were viz. normal (3.21±0.179, 16.48±1.432), subclinical mastitis with CMT positive milk samples with +1 Grade (4.21±0.138, 28.11±1.013), with +2 Grade (6.34±0.183, 34.50±1.034), with +3 Grade (7.96±0.213, 37.73±0.737) and buffaloes with clinical mastitis (10.21±0.220, 42.37±0.907) respectively, indicating an increasing trend in the values and the difference observed among various group was statistically significant. Conclusion: In conclusion, the results of the present study indicate that the concentration of milk SCC and alkaline phosphatase activity was higher in the milk of buffaloes with mastitis than in the milk of normal buffaloes. PMID:27047098

A Giant Occipital Encephalocele in Neonate with Spontaneous Hemorrhage into the Encephalocele Sac: Surgical Management

Science.gov (United States)

Satyarthee, Guru Dutta; Moscote-Salazar, Luis Rafael; Escobar-Hernandez, Nidia; Aquino-Matus, Jose; Puac-Polanco, Paulo Cesar; Hoz, Samer S; Calderon-Miranda, Willem Guillermo

2017-01-01

The presence of giant occipital encephalocele represents a surgical challenge. However, preoperative magnetic resonance imaging with venography can help in delineating relation of venous sinus, content of the sac and help classify occipital encephalocele into infra-torcular and torcular depending on the relation with position of torcula. However, the presence of old hemorrhage into encephalocele sac is extremely rare and in the detailed PubMed search, the authors could find one such case, reported by Nath et al. The author reports a case of giant occipital encephalocele; during surgery, evidence of old bleed was noted. Pertinent literature and management are reviewed briefly. PMID:29204205

Tools for visualization of phosphoinositides in the cell nucleus.

Science.gov (United States)

Kalasova, Ilona; Fáberová, Veronika; Kalendová, Alžběta; Yildirim, Sukriye; Uličná, Lívia; Venit, Tomáš; Hozák, Pavel

2016-04-01

Phosphoinositides (PIs) are glycerol-based phospholipids containing hydrophilic inositol ring. The inositol ring is mono-, bis-, or tris-phosphorylated yielding seven PIs members. Ample evidence shows that PIs localize both to the cytoplasm and to the nucleus. However, tools for direct visualization of nuclear PIs are limited and many studies thus employ indirect approaches, such as staining of their metabolic enzymes. Since localization and mobility of PIs differ from their metabolic enzymes, these approaches may result in incomplete data. In this paper, we tested commercially available PIs antibodies by light microscopy on fixed cells, tested their specificity using protein-lipid overlay assay and blocking assay, and compared their staining patterns. Additionally, we prepared recombinant PIs-binding domains and tested them on both fixed and live cells by light microscopy. The results provide a useful overview of usability of the tools tested and stress that the selection of adequate tools is critical. Knowing the localization of individual PIs in various functional compartments should enable us to better understand the roles of PIs in the cell nucleus.

Protein tyrosine phosphatases: regulatory mechanisms.

NARCIS (Netherlands)

den Hertog, J.; Ostman, A.; Bohmer, F.D.

2008-01-01

Protein-tyrosine phosphatases are tightly controlled by various mechanisms, ranging from differential expression in specific cell types to restricted subcellular localization, limited proteolysis, post-translational modifications affecting intrinsic catalytic activity, ligand binding and

Identification and characterization of an ATP.Mg-dependent protein phosphatase from pig brain

International Nuclear Information System (INIS)

Yang, S.D.; Fong, Y.L.

1985-01-01

Substantial amounts of ATP.Mg-dependent phosphorylase phosphatase (Fc. M) and its activator (kinase FA) were identified and extensively purified from pig brain, in spite of the fact that glycogen metabolism in the brain is of little importance. The brain Fc.M was completely inactive and could only be activated by ATP.Mg and FA, isolated either from rabbit muscle or pig brain. Kinetical analysis of the dephosphorylation of endogenous brain protein indicates that Fc.M could dephosphorylate 32 P-labeled myelin basic protein (MBP) and [ 32 P]phosphorylase alpha at a comparable rate and moreover, this associated MBP phosphatase activity was also strictly kinase FA/ATP.Mg-dependent, demonstrating that MBP is a potential substrate for Fc.M in the brain. By manipulating MBP and inhibitor-2 as specific potent phosphorylase phosphatase inhibitors, we further demonstrate that 1) Fc.M contains two distinct catalytic sites to dephosphorylate different substrates, and 2) brain MBP may be a physiological trigger involved in the regulation of protein phosphatase substrate specificity in mammalian nervous tissues

Disease Evolution and Response to Rapamycin in Activated Phosphoinositide 3-Kinase δ Syndrome: The European Society for Immunodeficiencies-Activated Phosphoinositide 3-Kinase δ Syndrome Registry

Directory of Open Access Journals (Sweden)

Maria Elena Maccari

2018-03-01

Full Text Available Activated phosphoinositide 3-kinase (PI3K δ Syndrome (APDS, caused by autosomal dominant mutations in PIK3CD (APDS1 or PIK3R1 (APDS2, is a heterogeneous primary immunodeficiency. While initial cohort-descriptions summarized the spectrum of clinical and immunological manifestations, questions about long-term disease evolution and response to therapy remain. The prospective European Society for Immunodeficiencies (ESID-APDS registry aims to characterize the disease course, identify outcome predictors, and evaluate treatment responses. So far, 77 patients have been recruited (51 APDS1, 26 APDS2. Analysis of disease evolution in the first 68 patients pinpoints the early occurrence of recurrent respiratory infections followed by chronic lymphoproliferation, gastrointestinal manifestations, and cytopenias. Although most manifestations occur by age 15, adult-onset and asymptomatic courses were documented. Bronchiectasis was observed in 24/40 APDS1 patients who received a CT-scan compared with 4/15 APDS2 patients. By age 20, half of the patients had received at least one immunosuppressant, but 2–3 lines of immunosuppressive therapy were not unusual before age 10. Response to rapamycin was rated by physician visual analog scale as good in 10, moderate in 9, and poor in 7. Lymphoproliferation showed the best response (8 complete, 11 partial, 6 no remission, while bowel inflammation (3 complete, 3 partial, 9 no remission and cytopenia (3 complete, 2 partial, 9 no remission responded less well. Hence, non-lymphoproliferative manifestations should be a key target for novel therapies. This report from the ESID-APDS registry provides comprehensive baseline documentation for a growing cohort that will be followed prospectively to establish prognostic factors and identify patients for treatment studies.

Ovule-to-seed development in Dovyalis caffra (Salicaceae: Flacourtieae with notes on the taxonomic significance of the extranucellar embryo sac

Directory of Open Access Journals (Sweden)

E. M. A. Steyn

2005-08-01

Full Text Available Dovyalis caffra (Hook.f. & Harv. Hook.f. is a widespread and horticulturally important southern African endemic. Here described, ovule-to-seed development represents the first embryological information on this genus of the tribe Flacourtieae, Salicaceae  sensu lato. Results are discussed in the light of data available on the embryology of the order Malpighiales in general and on the tribe Flacourtieae in particular. It is clear that Dovyalis E.Mey. ex Am. shares many characters with other members of the Flacourtieae. Ovules of D. caffra are anatropous. bitegmic and crassinucellate with both bisporic Allium- and monosporic Polygonum-type embryo sacs. One of the most characteristic embryological features of the tribe is the pres­ence of an unusual, extranucellar embryo sac that stretches halfway up into the micropyle. Since this extraordinary-shaped embryo sac also defines the embryo sacs of Salix L. and Populus L., it is suggested that the character provides strong sup­port for the proposed close phylogenetic link between tribes Flacourtieae and Saliceae of Salicaceae sensu lato.

Influence of acid phosphatase activity on the saccharification of potato maltodextrins by Aspergillus niger glucoamylase

Energy Technology Data Exchange (ETDEWEB)

Zyla, K. (Akademia Rolnicza, Cracow (Poland). Dept. of Biotechnology)

1990-01-01

A preparation of Aspergillus niger acid phosphatase, which had the temperature optimum 60deg C, pH optimum 1.8-3.0; good stability at pH 4-5, the ability to hydrolyze glucose-6-phosphate at a high rate, and substantial lack of glucogenic activities, was used simultaneously with a glucoamylase in order to learn its influence on the saccharification of potato maltodextrins. The addition of the acid phosphatase activity in amounts that gave the 50 fold increase, as compared to phosphatase activity which naturally occurs in the gluocoamylase (GA) preparation 'AMG-200', was found to influence on the DE level, mainly at the high substrate concentration (40% d.s.) and low glucoamylase dosage (60-100 GAU/kg d.s.). It may also be possible, when using the acid phosphatase addition, to shorten the saccharification time. (orig.).

Genome wide identification of wheat and Brachypodium type one protein phosphatases and functional characterization of durum wheat TdPP1a

OpenAIRE

Bradai, Mariem; Mahjoubi, Habib; Chini, Andrea; Chabouté, Marie-Edith; Hanin, Moez; Ebel, Chantal

2018-01-01

Reversible phosphorylation is an essential mechanism regulating signal transduction during development and environmental stress responses. An important number of dephosphorylation events in the cell are catalyzed by type one protein phosphatases (PP1), which catalytic activity is driven by the binding of regulatory proteins that control their substrate specificity or subcellular localization. Plants harbor several PP1 isoforms accounting for large functional redundancies. While animal PP1s we...

Targeted deletion of kidney glucose-6 phosphatase leads to nephropathy

NARCIS (Netherlands)

Clar, Julie; Gri, Blandine; Calderaro, Julien; Birling, Marie-Christine; Herault, Yann; Smit, G. Peter A.; Mithieux, Gilles; Rajas, Fabienne

2014-01-01

Renal failure is a major complication that arises with aging in glycogen storage disease type 1a and type 1b patients. In the kidneys, glucose-6 phosphatase catalytic subunit (encoded by G6pc) deficiency leads to the accumulation of glycogen, an effect resulting in marked nephromegaly and