WorldWideScience

Sample records for biphosphates

  1. Inhibition of fructose-1,6-bisphosphatase by fructose 2,6-biphosphate.

    OpenAIRE

    Van Schaftingen, E; Hers, H G

    1981-01-01

    Fructose 2,6-bisphosphate, a known powerful stimulator of phosphofructokinase [Van Schaftingen, E., Hue, L. & Hers, H.-G. (1980) Biochem. J. 192, 897-901] was found to inhibit, at micromolar concentrations, liver and muscle fructose-1,6-biphosphate (D-fructose-1,6-bisphosphate 1-phosphohydrolase, EC 3.1.3.11). The main characteristics of this inhibition are that (i) it is much stronger at low than at high substrate concentrations, (ii) it changes the substrate saturation curve from almost hyp...

  2. An operationally flexible fuel cell based on quaternary ammonium-biphosphate ion pairs

    Science.gov (United States)

    Lee, Kwan-Soo; Spendelow, Jacob S.; Choe, Yoong-Kee; Fujimoto, Cy; Kim, Yu Seung

    2016-09-01

    Fuel cells are promising devices for clean power generation in a variety of economically and environmentally significant applications. Low-temperature proton exchange membrane (PEM) fuel cells utilizing Nafion require a high level of hydration, which limits the operating temperature to less than 100 ∘C. In contrast, high-temperature PEM fuel cells utilizing phosphoric acid-doped polybenzimidazole can operate effectively up to 180 ∘C however, these devices degrade when exposed to water below 140 ∘C. Here we present a different class of PEM fuel cells based on quaternary ammonium-biphosphate ion pairs that can operate under conditions unattainable with existing fuel cell technologies. These fuel cells exhibit stable performance at 80-160 ∘C with a conductivity decay rate more than three orders of magnitude lower than that of a commercial high-temperature PEM fuel cell. By increasing the operational flexibility, this class of fuel cell can simplify the requirements for heat and water management, and potentially reduce the costs associated with the existing fully functional fuel cell systems.

  3. Study on P2O5 recovery in production of sodium dihydrogen phosphate with calcium biphosphate%磷酸二氢钙制备磷酸二氢钠磷收率研究

    Institute of Scientific and Technical Information of China (English)

    王勃; 向伟; 陈红琼; 应建康

    2012-01-01

    Calcium biphosphate is an important product in fine processing wet-process phosphoric acid (WPA), it conforms to the present market needing to develop the middle production of calcium biphosphate refined series product, and is of great significance.Process conditions of preparation of sodium dihydrogen phosphate with double decomposition reaction between calcium biphosphate and sodium sulfate were studied,and product by concentrated crystallization process was obtained. Influences of the reaction temperature, mix ratio of sodium sulfate to calcium biphosphate, ratio of liquid to solid, and reaction time on P2O5 recovery were investigated.Optimal process parameters of the reaction obtained were as follows:the reaction temperature was 50 ℃, mix ratio of sodium sulfate to calcium biphosphate was 1.2:1, mass ratio of liquid to solid was 4:1, and reaction time was 120 min.Under the conditions,the P2O5 recovery was 79.1%.Advantages of this process were the purity of product was high, process flow was short, and operation was simple etc.%磷酸二氢钙是湿法磷酸精细加工的重要产品,开发以磷酸二氢钙为中间产物的精加工系列产品符合目前市场需求.研究了磷酸二氢钙与硫酸钠复分解反应制备磷酸二氢钠的工艺条件,并通过浓缩结晶得到磷酸二氢钠产品.对反应温度、物料配比、液固比以及反应时间诸因素对磷收率的影响进行了研究,确定了复分解过程适宜的工艺条件:反应温度为50℃,物料配比(硫酸钠与磷酸二氢钙物质的量比)为1.2∶1,液固比(质量比)为4∶1,反应时间为120 min.在此条件下磷收率可达79.1%.该工艺具产品纯度高、工艺流程简单、操作简便等优点.

  4. Study of the properties of Ribulose 1,5-biphosphate carboxylase/oxygenase from maize (Zea mays) and wheat (Triticum aestivum) by incorporation of CO2 marking 14C

    International Nuclear Information System (INIS)

    After a bibliografic review of the properties of RuBP-carboxylase/oxygenase, a methodology is described which allows the treatment of a large number of samples for the assay of the enzyme activity. 14CO3HNa is used as a marker for the counting of the incorporated radioactivity as acid insoluble material. 14''CC2 from the labeled sodium bicarbonate is the species used by the enzyme both as an activator as well as a substrate. The following experiments are described and its results given: Determination of the optimal conditions for the activation of the enzyme; study of the kinetics of the catalytic action; effect of the Mg2 concentration and determination of the Km(s) from CO2 and ribulose 1,5-biphosphate; also determination of the optimum pH at different concentrations of CO22 and Mg2. (Author) 64 refs

  5. Comparação entre as soluções orais de manitol a 10% e bifosfato de sódio no preparo mecânico do cólon Comparison between sodium biphosphate and 10% oral mannitol solutions for mechanical bowel preparation

    Directory of Open Access Journals (Sweden)

    Marssoni Deconto Rossoni

    2008-10-01

    Full Text Available OBJETIVO: Comparar o uso das soluções orais de manitol a 10% e de bifosfato de sódio no preparo mecânico do cólon quanto a qualidade da limpeza, a tolerabilidade e as alterações hidroeletrolíticas e da osmolaridade plasmática. MÉTODO: Foram analisados 60 pacientes de modo randomizado, duplo-cego e prospectivo, com indicação de colonoscopia. A qualidade da limpeza intestinal foi analisada pelo examinador através da classificação de Beck. A tolerabilidade à ingestão baseou-se na pesquisa do gosto, presença ou não de desconforto, aparecimento de efeitos adversos e a quantidade da solução ingerida. Foram dosados o sódio, potássio, cálcio, magnésio, fósforo, uréia, creatinina, glicose, hematócrito, hemoglobina e calculado a osmolaridade plasmática, antes e após a ingestão da solução oral de preparo inestinal. RESULTADOS: Ambas as soluções atingiram qualidade de preparo classificado como bom ou superior em mais de 80% dos pacientes. O uso do bifosfato de sódio determinou menor desconforto e melhor tolerância, apesar de não ter sido superior ao manitol quanto à análise do gosto e presença de efeitos adversos. O bifosfato induziu ao aumento e o manitol a uma redução da osmolaridade, reflexo do que ocorreu com o sódio plasmático nos dois grupos respectivamente. O bifosfato ainda determinou alteração significativa dos níveis séricos de fósforo, cálcio, magnésio e potássio, sem repercussões clínicas. CONCLUSÃO: Ambos os tipos de preparo intestinal determinaram qualidade de limpeza adequada. O bifosfato de sódio, apesar de melhor tolerado, determina maior quantidade de alterações hidroeletrolíticas.BACKGROUND: To compare the use of sodium biphosphate and 10% mannitol solutions for mechanical bowel preparation in terms of cleansing quality, tolerability, disorder in water and electrolyte balance, and plasma osmolality. METHOD: Sixty patients who had been referred for colonoscopy were analyzed in a

  6. Study of the properties of Ribulose 1,5-biphosphate carboxylase/oxygenase from maize (Zea mays) and wheat (Triticum aestivum) by incorporation of 14{sub C}O2; Estudio de las propiedades de la Ribulosa-1,5-Difosfato Carboxilasa/Oxigenasa de maiz (Zea Mais) y de trigo (Triticum Aestivum), por incorporacion de CO{sub 2} marcado con 14{sub C}O2

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M. D.; Saez, R. M.

    1982-07-01

    After a bibliographic review of the properties of RuBP-carboxylase/oxygenase, a methodology is described which allows the treatment of a large number of samples for the assay of the enzyme activity. 14{sup C}O{sub 3}HNa is used as a marker for the counting of the incorporated radioactivity as acid insoluble material. 14''CC{sub 2} from the labeled sodium bicarbonate is the species used by the enzyme both as an activator as well as a substrate. The following experiments are described and its results given: Determination of the optimal conditions for the activation of the enzyme; study of the kinetics of the catalytic action; effect of the Mg{sup 2} concentration and determination of the Km{sub (s)} from CO{sub 2} and ribulose 1,5-biphosphate; also determination of the optimum pH at different concentrations of CO{sub 2}2 and Mg{sup 2}. (Author) 64 refs.

  7. Rational Design Synthesis and Evaluation of First Generation Inhibitors of the Giardia Lamblia Fructose-1 6-biphosphate Aldolase

    Energy Technology Data Exchange (ETDEWEB)

    Z Li; Z Liu; D Cho; J Zou; M Gong; R Breece; A Galkin; L Li; H Zhao; et al.

    2011-12-31

    Inhibitors of the Giardia lamblia fructose 1,6-bisphosphate aldolase (GlFBPA), which transforms fructose 1,6-bisphosphate (FBP) to dihydroxyacetone phosphate and glyceraldehyde 3-phosphate, were designed based on 3-hydroxy-2-pyridone and 1,2-dihydroxypyridine scaffolds that position two negatively charged tetrahedral groups for interaction with substrate phosphate binding residues, a hydrogen bond donor to the catalytic Asp83, and a Zn{sup 2+} binding group. The inhibition activities for the GlFBPA catalyzed reaction of FBP of the prepared alkyl phosphonate/phosphate substituted 3-hydroxy-2-pyridinones and a dihydroxypyridine were determined. The 3-hydroxy-2-pyridone inhibitor 8 was found to bind to GlFBPA with an affinity (K{sub i} = 14 {micro}M) that is comparable to that of FBP (K{sub m} = 2 {micro}M) or its inert analog TBP (K{sub i} = 1 {micro}M). The X-ray structure of the GlFBPA-inhibitor 8 complex (2.3 {angstrom}) shows that 8 binds to the active site in the manner predicted by in silico docking with the exception of coordination with Zn{sup 2+}. The observed distances and orientation of the pyridone ring O=C-C-OH relative to Zn{sup 2+} are not consistent with a strong interaction. To determine if Zn{sup 2+} coordination occurs in the GlFBPA-inhibitor 8 complex in solution, EXAFS spectra were measured. A four coordinate geometry comprised of the three enzyme histidine ligands and an oxygen atom from the pyridone ring O=C-C-OH was indicated. Analysis of the Zn{sup 2+} coordination geometries in recently reported structures of class II FBPAs suggests that strong Zn{sup 2+} coordination is reserved for the enediolate-like transition state, accounting for minimal contribution of Zn{sup 2+} coordination to binding of 8 to GlFBPA.

  8. Phosphatidylinositol 4,5-biphosphate (PIP2) modulates syntaxin-1A binding to sulfonylurea receptor 2A to regulate cardiac ATP-sensitive potassium (KATP) channels.

    Science.gov (United States)

    Xie, Li; Liang, Tao; Kang, Youhou; Lin, Xianguang; Sobbi, Roozbeh; Xie, Huanli; Chao, Christin; Backx, Peter; Feng, Zhong-Ping; Shyng, Show-Ling; Gaisano, Herbert Y

    2014-10-01

    Cardiac sarcolemmal syntaxin (Syn)-1A interacts with sulfonylurea receptor (SUR) 2A to inhibit ATP-sensitive potassium (KATP) channels. Phosphatidylinositol 4,5-bisphosphate (PIP2), a ubiquitous endogenous inositol phospholipid, known to bind Kir6.2 subunit to open KATP channels, has recently been shown to directly bind Syn-1A in plasma membrane to form Syn-1A clusters. Here, we sought to determine whether the interaction between Syn-1A and PIP2 interferes with the ability of Syn-1A to bind SUR2A and inhibit KATP channel activity. We found that PIP2 dose-dependently reduced SUR2A binding to GST-Syn-1A by in vitro pulldown assays. FRET studies in intact cells using TIRFM revealed that increasing endogenous PIP2 levels led to increased Syn-1A (-EGFP) cluster formation and a severe reduction in availability of Syn-1A molecules to interact with SUR2A (-mCherry) molecules outside the Syn-1A clusters. Correspondingly, electrophysiological studies employing SUR2A/Kir6.2-expressing HEK cells showed that increasing endogenous or exogenous PIP2 diminished the inhibitory effect of Syn-1A on KATP currents. The physiological relevance of these findings was confirmed by ability of exogenous PIP2 to block exogenous Syn-1A inhibition of cardiac KATP currents in inside-out patches of mouse ventricular myocytes. The effect of PIP2 on physical and functional interactions between Syn-1A and KATP channels is specific and not observed with physiologic concentrations of other phospholipids. To unequivocally demonstrate the specificity of PIP2 interaction with Syn-1A and its impact on KATP channel modulation by Syn-1A, we employed a PIP2-insensitive Syn-1A-5RK/A mutant. The Syn-1A-5RK/A mutant retains the ability to interact with SUR2A in both in vitro binding and in vivo FRET assays, although as expected the interaction is no longer disrupted by PIP2. Interestingly, at physiological PIP2 concentrations, Syn-1A-5RK/A inhibited KATP currents to a greater extent than Syn-1A-WT, indicating that the inhibitory effect of Syn-1A on KATP channels is not due to direct competition between Syn-1A and Kir6.2 for PIP2 binding. At high-dose PIP2, however, inhibition of KATP currents by Syn-1A-5RK/A was greatly reduced, likely overridden by the direct activating effect of PIP2 on KATP channels. Finally, depleting endogenous PIP2 with polyphosphoinositide phosphatase synaptojanin-1 known to disperse Syn-1A clusters, freed Syn-1A from Syn-1A clusters to bind SUR2A, causing optimal inhibition of KATP channels. These results taken together led us to conclude that PIP2 affects cardiac KATP channels not only by its actions on the channel directly but also by multi-modal effects of dynamically modulating Syn-1A mobility from Syn-1A clusters and thereby the availability of Syn-1A to inhibit KATP channels via interaction with SUR2A on the plasma membrane. PMID:25073062

  9. Disease: H00692 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available es the phosphatidylinositol enzyme (4, 5) biphosphate 5-phosphatase present in the Golgi complex. The symp...toms of Lowe syndrome include congenital cataracts and glaucoma, delay in neuropsyc

  10. Evolution of prokaryote and eukaryote lines inferred from sequence evidence

    Science.gov (United States)

    Hunt, L. T.; George, D. G.; Yeh, L.-S.; Dayhoff, M. O.

    1984-01-01

    This paper describes the evolution of prokaryotes and early eukaryotes, including their symbiotic relationships, as inferred from phylogenetic trees of bacterial ferredoxin, 5S ribosomal RNA, ribulose-1,5-biphosphate carboxylase large chain, and mitochondrial cytochrome oxidase polypeptide II.

  11. Dicty_cDB: SFA739 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 2 X65742 |X65742.1 S.oleracae ALDCyt mRNA for fructose-1,6-biphosphate aldolase. 56 7e-06 2 AW782996 |AW782996.1 ra22b05.y1 Bird...25 FRUCTOSE-BIPHOSPHATE ALDOLASE ;, mRNA sequence. 46 0.22 1 AW828480 |AW828480.1 ra62c09.y1 Bird

  12. Acetaldehyde stimulation of net gluconeogenic carbon movement from applied malic acid in tomato fruit pericarp tissue

    Energy Technology Data Exchange (ETDEWEB)

    Halinska, A.; Frenkel, C. (Rutgers, The State Univ. of New Jersey, New Brunswick (United States))

    1991-03-01

    Applied acetaldehyde is known to lead to sugar accumulation in fruit including tomatoes (Lycopersicon esculentum) presumably due to stimulation of gluconeogenesis. This conjecture was examined using tomato fruit pericarp discs as a test system and applied l-(U-{sup 14}C)malic acid as the source for gluconeogenic carbon mobilization. Results indicate that malic and perhaps other organic acids are carbon sources for gluconeogenesis occurring normally in ripening tomatoes. The process is stimulated by acetaldehyde apparently by attenuating the fructose-2,6-biphosphate levels. The mode of the acetaldehyde regulation of fructose-2,6-biphosphate metabolism awaits clarification.

  13. Phosphatidylinositol 4-phosphate 5-kinases in the regulation of T cell activation

    Directory of Open Access Journals (Sweden)

    Loretta eTuosto

    2016-05-01

    Full Text Available Phosphatidylinositol 4,5-biphosphate kinases (PIP5K are critical regulators of T cell activation being the main enzymes involved in the synthesis of phosphatidylinositol 4,5-biphosphate (PIP2. PIP2 is indeed a pivotal regulator of the actin cytoskeleton, thus controlling T cell polarization and migration, stable adhesion to antigen presenting cells (APC, spatial organization of the immunological synapse (IS, and costimulation. Moreover, PIP2 serves also as a precursor for the second messengers inositol triphosphate (IP3, diacylglycerol (DAG and phosphatidylinositol 3,4,5-triphosphate (PIP3, which are essential for the activation of signalling pathways regulating cytokine production, cell cycle progression, survival, metabolism and differentiation. Here, we discuss the impact of PIP5Ks on several T lymphocyte functions with a specific focus on the role of CD28 co-stimulation in PIP5K compartimentalization and activation.

  14. A biochemical and genetic study of Leishmania donovani pyruvate kinase.

    Science.gov (United States)

    Sandoval, Will; Isea, Raúl; Rodriguez, Evelyn; Ramirez, Jose Luis

    2008-11-15

    Here we present a biochemical and molecular biology study of the enzyme pyruvate kinase (PYK) from the parasitic protozoa Leishmania donovani. The PYK gene was cloned, mutagenised and over expressed and its kinetic parameters determined. Like in other kinetoplastids, L. donovani PYK is allosterically stimulated by the effector fructose 2,6 biphosphate and not by fructose 1,6 biphosphate. When the putative effector binding site of L. donovani PYK was mutagenised, we obtained two mutants with extreme kinetic behavior: Lys453Leu, which retained a sigmoidal kinetics and was little affected by the effector; and His480Gln, which deployed a hyperbolic kinetics that was not changed by the addition of the effector. Molecular Dynamics (MD) studies revealed that the mutations not only altered the effector binding site of L. donovani PYK but also changed the folding of its domain C. PMID:18725273

  15. Role of the photosystem II-associated CAH3 in the oxygen evolving machinery in Chlamydomonas reinhardtii

    OpenAIRE

    Rende, Umut

    2012-01-01

    One of the most abundant proteins on the Earth is ribulose-1,5-biphosphate carboxylase/oxygenase (RUBISCO). RUBISCO is a CO2 fixing enzyme in oxygenic photosynthetic organisms that it has low affinity for CO2. When CO2 is the limiting factor in the environment, RUBISCO works inefficiently due to its oxygenase activity. Some higher plants and aquatic photosynthetic organisms, such as the green alga Chlamydomonas reinhardtii; therefore, evolved Carbon Concentrating Mechanisms to acquire and to ...

  16. Ibrutinib interferes with the cell-mediated anti-tumor activities of therapeutic CD20 antibodies: implications for combination therapy

    OpenAIRE

    Roit, Fabio Da; Patrick J Engelberts; Taylor, Ronald P.; Breij, Esther C.W.; Gritti, Giuseppe; Rambaldi, Alessandro; Introna, Martino; Parren, Paul W H I; Beurskens, Frank J; Golay, Josée

    2015-01-01

    The novel Bruton tyrosine kinase inhibitor ibrutinib and phosphatidyl-4-5-biphosphate 3-kinase-δ inhibitor idelalisib are promising drugs for the treatment of chronic lymphocytic leukemia and B-cell non-Hodgkin lymphoma, either alone or in combination with anti-CD20 antibodies. We investigated the possible positive or negative impact of these drugs on all known mechanisms of action of both type I and type II anti-CD20 antibodies. Pretreatment with ibrutinib for 1 hour did not increase direct ...

  17. PIP3 but not PIP2 increases GLUT4 surface expression and glucose metabolism mediated by AKT/PKCζ/λ phosphorylation in 3T3L1 adipocytes

    OpenAIRE

    Manna, Prasenjit; Jain, Sushil K.

    2013-01-01

    PIP3 (phosphatidylinositol-3,4,5-triphosphate) and PIP2 (phosphatidylinositol-4,5-biphosphate) are two well-known membrane bound polyphosphoinositides. Diabetes is associated with impaired glucose metabolism. Using a 3T3L1 adipocyte cell model, this study investigated the roles of PIP3 and PIP2 on insulin stimulated glucose metabolism in high glucose (HG) treated cells. Exogenous PIP3 supplementation (1, 5, or 10 nM) increased the phosphorylation of AKT and PKCζ/λ, which in turn upregulated G...

  18. Drug: D06799 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D06799 Crude, Drug Longgu (JP16); Powdered longgu (JP16); Fossilized mammal bones (...56], Strontium [CPD:C13884], Zirconium, Rubidium [CPD:C17061], Potassium [CPD:C00238], Titanium, Aluminum, O...ajor component: Calcium carbonate [CPD:C08129], Calcium biphosphate [CPD:C13556] Therapeutic category of dru...gs in Japan [BR:br08301] 5 Crude drugs and Chinese medicine formulations 51 Crude drugs 510 Crude drugs 5100 Crude dru...icine in Japan [BR:br08304] Crude Drugs Drugs for Qi Sedative drugs D06799 Longgu; Fossilized mammal bones Crude drugs [BR:br08305] Animals Mammals D06799 Longgu PubChem: 47208450 ...

  19. Structure-Driven Pharmacology of Transient Receptor Potential Channel Vanilloid 1.

    Science.gov (United States)

    Díaz-Franulic, Ignacio; Caceres-Molina, Javier; Sepulveda, Romina V; Gonzalez-Nilo, Fernando; Latorre, Ramon

    2016-09-01

    The transient receptor potential vanilloid 1 (TRPV1) ion channel is a polymodal receptor that mediates the flux of cations across the membrane in response to several stimuli, including heat, voltage, and ligands. The best known agonist of TRPV1 channels is capsaicin, the pungent component of "hot" chili peppers. In addition, peptides found in the venom of poisonous animals, along with the lipids phosphatidylinositol 4,5-biphosphate, lysophosphatidic acid, and cholesterol, bind to TRPV1 with high affinity to modulate channel gating. Here, we discuss the functional evidence regarding ligand-dependent activation of TRPV1 channels in light of structural data recently obtained by cryoelectron microscopy. This review focuses on the mechanistic insights into ligand binding and allosteric gating of TRPV1 channels and the relevance of accurate polymodal receptor biophysical characterization for drug design in novel pain therapies. PMID:27335334

  20. PIP2: choreographer of actin-adaptor proteins in the HIV-1 dance

    Science.gov (United States)

    Rocha-Perugini, Vera; Gordon-Alonso, Mónica; Sánchez-Madrid, Francisco

    2014-01-01

    The actin cytoskeleton plays a key role during the replication cycle of human immunodeficiency virus-1 (HIV-1). HIV-1 infection is affected by cellular proteins that influence the clustering of viral receptors or the subcortical actin cytoskeleton. Several of these actin-adaptor proteins are controlled by the second messenger phosphatidylinositol 4,5-biphosphate (PIP2), an important regulator of actin organization. PIP2 production is induced by HIV-1 attachment and facilitates viral infection. However, the importance of PIP2 in regulating cytoskeletal proteins and thus HIV-1 infection has been overlooked. This review examines recent reports describing the roles played by actin-adaptor proteins during HIV-1 infection of CD4+ T cells, highlighting the influence of the signaling lipid PIP2 in this process. PMID:24768560

  1. Expression and Purification of PI3 Kinase {alpha} and Development of an ATP Depletion and an AlphaScreen PI3 Kinase Activity Assay

    DEFF Research Database (Denmark)

    Boldyreff, Brigitte; Rasmussen, Tine L; Jensen, Hans H;

    2008-01-01

    Phosphoinositide-3-kinases are important targets for drug development because many proteins in the PI3 kinase signaling pathway are mutated, hyperactivated, or overexpressed in human cancers. Here, the authors coexpressed the human class Ia PI3 kinase p110alpha catalytic domain with an N...... was optimized by testing different lipids as substrates, as well as various kinase and lipid concentrations. Furthermore, they analyzed autophosphorylation of p110alpha/p85alpha and determined the IC50 for wortmannin, a known PI3 kinase inhibitor. The IC50 for wortmannin was determined to be 7 nM. From...... a selection of substrates, phosphatidylinositol-4, 5-biphosphate turned out to be the best substrate at a concentration of 50 microM. p110alpha/p85alpha underwent autophosphorylation most prominently at the p85alpha subunit. However, in the presence of lipid substrate, the autophosphorylation was negligible...

  2. Structure-Driven Pharmacology of Transient Receptor Potential Channel Vanilloid 1.

    Science.gov (United States)

    Díaz-Franulic, Ignacio; Caceres-Molina, Javier; Sepulveda, Romina V; Gonzalez-Nilo, Fernando; Latorre, Ramon

    2016-09-01

    The transient receptor potential vanilloid 1 (TRPV1) ion channel is a polymodal receptor that mediates the flux of cations across the membrane in response to several stimuli, including heat, voltage, and ligands. The best known agonist of TRPV1 channels is capsaicin, the pungent component of "hot" chili peppers. In addition, peptides found in the venom of poisonous animals, along with the lipids phosphatidylinositol 4,5-biphosphate, lysophosphatidic acid, and cholesterol, bind to TRPV1 with high affinity to modulate channel gating. Here, we discuss the functional evidence regarding ligand-dependent activation of TRPV1 channels in light of structural data recently obtained by cryoelectron microscopy. This review focuses on the mechanistic insights into ligand binding and allosteric gating of TRPV1 channels and the relevance of accurate polymodal receptor biophysical characterization for drug design in novel pain therapies.

  3. Oral immunization of broiler chickens against necrotic enteritis with an attenuated Salmonella vaccine vector expressing Clostridium perfringens antigens.

    Science.gov (United States)

    Kulkarni, R R; Parreira, V R; Sharif, S; Prescott, J F

    2008-08-01

    Necrotic enteritis (NE) in broiler chickens is caused by Clostridium perfringens but currently no effective vaccine is available. Our previous study showed that certain C. perfringens secreted proteins when administered intramuscularly protected chickens against experimental infection. In the current study, genes encoding three C. perfringens proteins: fructose-biphosphate-aldolase (FBA), pyruvate:ferredoxin-oxidoreductase (PFOR) and hypothetical protein (HP), were cloned into an avirulent Salmonella enterica sv. typhimurium vaccine vector. Broiler chickens immunized orally with recombinant Salmonella expressing FBA or HP proteins were significantly protected against NE challenge. Immunized birds developed serum and mucosal antibodies to both clostridial and Salmonella antigens. This study showed the oral immunizing ability of two C. perfringens antigens against NE in broiler chickens through an attenuated Salmonella vaccine vector. PMID:18597901

  4. [Phospholipids and structural modification of tissues and cell membranes for adaptation in high altitude mountains].

    Science.gov (United States)

    Iakovlev, V M; Vishnevskiĭ, A A; Shanazarov, A S

    2012-01-01

    The nature of the impact of physical factors of high altitudes (3200 m) on the lipids of tissues and membranes of animals was researched. It was established that the adaptation process in Wistar rats was followed by peroxide degradation and subsequent modification of the phospholipids' structure of tissues and microsomal membranes. Adaptive phospholipids reconstruction takes place in microsomal membranes in the tissues of the lungs, brain, liver and skeletal muscles. Together with this, the amount of phosphatidylinositol and phosphatidic acid accumulates, indicating that the hydrolysis of phosphatidylinositol-4, 5 biphosphate to diacylglycerol and secondary messenger--inositol triphosphate, occurs. A decrease in temperature adaptation (+10 degrees C) leads to a more noticeable shift in peroxide oxidation of lipids, phospholipid structure in the tissues and membranes rather than adaptation in thermoneutral conditions (+30 degrees C). Modification of lipid composition of tissues and cell membranes in the highlands obviously increases the adaptive capabilities of cells of the whole body: physical performance and resistance to hypoxia increases in animals. PMID:22586936

  5. Compensation processes of Aleppo pine (Pinus halepensis Mill.) to ozone exposure and drought stress

    International Nuclear Information System (INIS)

    A long-term experiment was performed to study the effects of O3 and drought-stress (DS) on Aleppo pine seedlings (Pinus halepensis Mill.) exposed in open-top chambers. Ozone reduced gas exchange rates, ribulose-1,5-biphosphate carboxylase/oxygenase activity (Rubisco), aboveground C and needle N concentrations and C/N ratio and Ca concentrations of the twigs under 3 mm (twigsPd), C/N ratio, twigs<3 Ca, plant growth, aerial biomass and increased N, twigs with a diameter above 3 mm P and Mg concentrations. The combined exposure to both stresses increased N concentrations of twigs<3 and roots and aboveground biomass K content and decreased root C, maximum daily assimilation rate and instantaneous water use efficiency. The sensitivity of Aleppo pine to both stresses is determined by plant internal resource allocation and compensation mechanisms to cope with stress. - Ozone and drought stress induce the activation of similar processes related to C and N metabolism

  6. [Phospholipids and structural modification of tissues and cell membranes for adaptation in high altitude mountains].

    Science.gov (United States)

    Iakovlev, V M; Vishnevskiĭ, A A; Shanazarov, A S

    2012-01-01

    The nature of the impact of physical factors of high altitudes (3200 m) on the lipids of tissues and membranes of animals was researched. It was established that the adaptation process in Wistar rats was followed by peroxide degradation and subsequent modification of the phospholipids' structure of tissues and microsomal membranes. Adaptive phospholipids reconstruction takes place in microsomal membranes in the tissues of the lungs, brain, liver and skeletal muscles. Together with this, the amount of phosphatidylinositol and phosphatidic acid accumulates, indicating that the hydrolysis of phosphatidylinositol-4, 5 biphosphate to diacylglycerol and secondary messenger--inositol triphosphate, occurs. A decrease in temperature adaptation (+10 degrees C) leads to a more noticeable shift in peroxide oxidation of lipids, phospholipid structure in the tissues and membranes rather than adaptation in thermoneutral conditions (+30 degrees C). Modification of lipid composition of tissues and cell membranes in the highlands obviously increases the adaptive capabilities of cells of the whole body: physical performance and resistance to hypoxia increases in animals.

  7. Tobacco guard cells fix CO2 by both Rubisco and PEPcase while sucrose acts as a substrate during light-induced stomatal opening.

    Science.gov (United States)

    Daloso, Danilo M; Antunes, Werner C; Pinheiro, Daniela P; Waquim, Jardel P; Araújo, Wagner L; Loureiro, Marcelo E; Fernie, Alisdair R; Williams, Thomas C R

    2015-11-01

    Transcriptomic and proteomic studies have improved our knowledge of guard cell function; however, metabolic changes in guard cells remain relatively poorly understood. Here we analysed metabolic changes in guard cell-enriched epidermal fragments from tobacco during light-induced stomatal opening. Increases in sucrose, glucose and fructose were observed during light-induced stomatal opening in the presence of sucrose in the medium while no changes in starch were observed, suggesting that the elevated fructose and glucose levels were a consequence of sucrose rather than starch breakdown. Conversely, reduction in sucrose was observed during light- plus potassium-induced stomatal opening. Concomitant with the decrease in sucrose, we observed an increase in the level as well as in the (13) C enrichment in metabolites of, or associated with, the tricarboxylic acid cycle following incubation of the guard cell-enriched preparations in (13) C-labelled bicarbonate. Collectively, the results obtained support the hypothesis that sucrose is catabolized within guard cells in order to provide carbon skeletons for organic acid production. Furthermore, they provide a qualitative demonstration that CO2 fixation occurs both via ribulose-1,5-biphosphate carboxylase/oxygenase (Rubisco) and phosphoenolpyruvate carboxylase (PEPcase). The combined data are discussed with respect to current models of guard cell metabolism and function.

  8. Synthesis of nitro(benzo)thiazole acetamides and in vitro antiprotozoal effect against amitochondriate parasites Giardia intestinalis and Trichomonas vaginalis.

    Science.gov (United States)

    Navarrete-Vázquez, Gabriel; Chávez-Silva, Fabiola; Colín-Lozano, Blanca; Estrada-Soto, Samuel; Hidalgo-Figueroa, Sergio; Guerrero-Álvarez, Jorge; Méndez, Sara T; Reyes-Vivas, Horacio; Oria-Hernández, Jesús; Canul-Canché, Jaqueline; Ortiz-Andrade, Rolffy; Moo-Puc, Rosa

    2015-05-01

    We synthesized four 5-nitrothiazole (1-4) and four 6-nitrobenzothiazole acetamides (5-8) using an easy two step synthetic route. All compounds were tested in vitro against amitochondriate parasites Giardia intestinalis and Trichomonas vaginalis, showing excellent antiprotozoal effects. IC₅₀'s of the most potent compounds range from nanomolar to low micromolar order, being more active than their drugs of choice. Compound 1 (IC₅₀=122 nM), was 44-times more active than Metronidazole, and 10-fold more effective than Nitazoxanide against G. intestinalis and showed good trichomonicidal activity (IC₅₀=2.24 μM). This compound did not display in vitro cytotoxicity against VERO cells. The in vitro inhibitory effect of compounds 1-8 and Nitazoxanide against G. intestinalis fructose-1,6-biphosphate aldolase (GiFBPA) was evaluated as potential drug target, showing a clear inhibitory effect over the enzyme activity. Molecular docking of compounds 1, 4 and Nitazoxanide into the ligand binding pocket of GiFBPA, revealed contacts with the active site residues of the enzyme. Ligand efficiency metrics of 1 revealed optimal combinations of physicochemical and antiprotozoal properties, better than Nitazoxanide.

  9. Continuous Measuring Method of Sulfuric Acid and Phosphoric Acid in Steel Electropolishing Bath%钢铁电抛光溶液中硫酸和磷酸的连续测定方法

    Institute of Scientific and Technical Information of China (English)

    郭崇武

    2013-01-01

    研究了在测定钢铁电抛光溶液中硫酸和磷酸时所用的掩蔽剂,以甲基橙作指示剂,用氢氧化钠标准滴定溶液滴定硫酸和磷酸的总量,然后向试液中加亚铁氰化钾掩蔽亚铁离子,以酚酞作指示剂,继续用氢氧化钠标准滴定溶液滴定磷酸二氢根.该方法能有效消除亚铁离子对测定结果的影响,明显优于其它分析方法.%Masking agents of ferrous ions were studied for analysis of sulfuric acid and phosphoric acid in steel electropolishing bath. Total quantity of sulfuric acid and phosphoric acid were titrated by using methyl orange indicator and NaOH as titrant. Ferrous ions were masked with potassium ferrocyanide, and then the sodium biphosphate was titrated by utilizing phenolphthalein indicator and NaOH as titrant. Results showed that the influence of ferrous ions on the determination could be effectively eliminated by this method, and obviously, it was superior to other analytical methods.

  10. The response of Cupriavidus metallidurans CH34 to spaceflight in the international space station.

    Science.gov (United States)

    Leys, Natalie; Baatout, Sarah; Rosier, Caroline; Dams, Annik; s'Heeren, Catherine; Wattiez, Ruddy; Mergeay, Max

    2009-08-01

    The survival and behavior of Cupriavidus metallidurans strain CH34 were tested in space. In three spaceflight experiments, during three separate visits to the 'International Space Station' (ISS), strain CH34 was grown for 10-12 days at ambient temperature on mineral agar medium. Space- and earth-grown cells were compared post-flight by flow cytometry and using 2D-gel protein analysis. Pre-, in- and post-flight incubation conditions and experiment design had a significant impact on the survival and growth of CH34 in space. In the CH34 cells returning from spaceflight, 16 proteins were identified which were present in higher concentration in cells developed in spaceflight conditions. These proteins were involved in a specific response of CH34 to carbon limitation and oxidative stress, and included an acetone carboxylase subunit, fructose biphosphate aldolase, a DNA protection during starvation protein, chaperone protein, universal stress protein, and alkyl hydroperoxide reductase. The reproducible observation of the over-expression of these same proteins in multiple flight experiments, indicated that the CH34 cells could experience a substrate limitation and oxidative stress in spaceflight where cells and substrates are exposed to lower levels of gravity and higher doses of ionizing radiation. Bacterium C. metallidurans CH34 was able to grow normally under spaceflight conditions with very minor to no effects on cell physiology, but nevertheless specifically altered the expression of a few proteins in response to the environmental changes.

  11. Analysis of cbbL, nifH, and pufLM in Soils from the Sør Rondane Mountains, Antarctica, Reveals a Large Diversity of Autotrophic and Phototrophic Bacteria.

    Science.gov (United States)

    Tahon, Guillaume; Tytgat, Bjorn; Stragier, Pieter; Willems, Anne

    2016-01-01

    Cyanobacteria are generally thought to be responsible for primary production and nitrogen fixation in the microbial communities that dominate Antarctic ecosystems. Recent studies of bacterial communities in terrestrial Antarctica, however, have shown that Cyanobacteria are sometimes only scarcely present, suggesting that other bacteria presumably take over their role as primary producers and diazotrophs. The diversity of key genes in these processes was studied in surface samples from the Sør Rondane Mountains, Dronning Maud Land, using clone libraries of the large subunit of ribulose-1,5-biphosphate carboxylase/oxygenase (RuBisCO) genes (cbbL, cbbM) and dinitrogenase-reductase (nifH) genes. We recovered a large diversity of non-cyanobacterial cbbL type IC in addition to cyanobacterial type IB, suggesting that non-cyanobacterial autotrophs may contribute to primary production. The nifH diversity recovered was predominantly related to Cyanobacteria, particularly members of the Nostocales. We also investigated the occurrence of proteorhodopsin and anoxygenic phototrophy as mechanisms for non-Cyanobacteria to exploit solar energy. While proteorhodopsin genes were not detected, a large diversity of genes coding for the light and medium subunits of the type 2 phototrophic reaction center (pufLM) was observed, suggesting for the first time, that the aerobic photoheterotrophic lifestyle may be important in oligotrophic high-altitude ice-free terrestrial Antarctic habitats.

  12. Role of the Rubisco small subunit. Final report for period May 1, 1997--April 30,2000

    Energy Technology Data Exchange (ETDEWEB)

    Spreitzer, Robert J.

    2000-10-04

    CO{sub 2} and O{sub 2} are mutually competitive at the active site of ribulose-1,5-biphosphate (RuBP) carboxylase/oxygenase (Rubisco). Rubisco contains two subunits, each present in eight copies. The 15-kD small subunit is coded by a family of nuclear RbcS genes. Until now, the role of the small subunit in Rubisco structure or catalytic efficiency is not known. Because of other work in eliminating the two RbcS genes in the green algo Chlamydomonas reinhardtii, it is now possible to address questions about the structure-function relationships of the eukaryotic small subunit. There are three specific aims in this project: (1) Alanine scanning mutagenesis is being used to dissect the importance of the {beta}A/{beta}B loop, a feature unique to the eukaryotic small subunit. (2) Random mutagenesis is being used to identify additional residues or regions of the small subunit that are important for holoenzyme assembly and function. (3) Attempts are being made to express foreign small subunits in Chlamydomonas to examine the contribution of small subunits to holoenzyme assembly, catalytic efficiency, and CO{sub 2}/O{sub 2} specificity.

  13. Oligo-carrageenan kappa increases C, N and S assimilation, auxin and gibberellin contents, and growth in Pinus radiata trees

    Institute of Scientific and Technical Information of China (English)

    Silvia Saucedo; Rodrigo A Contreras; Alejandra Moenne

    2015-01-01

    Oligo-carrageenans (OCs) obtained from pure carrageenans extracted from marine red algae stimulate growth by enhancing photosynthesis and basal metabolism in tobacco plants and Eucalyptus trees. In addition, OCs stimulate secondary metabolism, increasing the level of metabolites involved in defense against pathogens. In this work, we analyzed the effect of OC kappa on the increase in height, in activities of basal metabolism enzymes in-volved in carbon, nitrogen and sulphur assimilation, ribu-lose 1,5 biphosphate carboxylase/oxygenase (rubisco), glutamate dehydrogenase (GDH) and O-acetylserine thiol-lyase (OASTL), and in the level of growth-promoting hormones, the auxin indole acetic acid (IAA) and the gibberellin GA3, in pine (Pinus radiata) trees treated with OC kappa at concentrations of 1 and 5 mg mL-1 and cultivated for 9 months without additional treatment. Pines treated with OC kappa at 1 mg mL-1 showed a similar increase in height but displayed a higher increased in total chlorophyll, activities of rubisco, GDH and OASTL and level of IAA and GA3 than those treated with OC kappa at 5 mg mL-1. Thus, OC kappa stimulates growth and basal metabolism and increases the level of growth-promoting hormones in pine trees, mainly at 1 mg mL-1.

  14. Effect of insulin on human erythrocyte metabolism

    International Nuclear Information System (INIS)

    Insulin effects on the metabolism of human erythrocytes have been demonstrated. Under hypoxic conditions, glucose utilization was increased in insulin treated red cell suspensions at pH 7.32 and pH 7.66, but not at pH 7.48. A dose-response study at pH 7.31 revealed that glucose utilization was inhibited at lower insulin concentrations, i.e., 0.2 nM, whereas the simulatory effects were seen at relatively higher levels, i.e., 5.8-6.3 nM. Lactate production, and cellular content of 2,3-bisphosphoglycerate, fructose 1,6-biphosphate and triose 3-phosphate were unchanged in the presence of this hormone. Hexose monophosphate shunt activity was increased, but the amount of change was too small to account for the additional glucose used by the insulin-treated cells. Under ambient air conditions, insulin inhibited glucose utilization by dibutyryl-adenosine 3'-5'-cyclic monophosphate-treated red cells but lactate to production was unchanged. Insulin appeared to inhibit 32P incorporation into some, but not all, of the membrane proteins phosphorylated in intact cells incubated in the presence of dibutyryl-adenosine 3',5'-cyclic monophosphate. Insulin did not alter the rate or distribution of 32P incorporation into membrane proteins in the absence of this nucleotide. This studies suggest that the erythrocyte may be a useful model for future investigations into the molecular mechanism of insulin action

  15. Phospholipid dysregulation contributes to ApoE4-associated cognitive deficits in Alzheimer's disease pathogenesis.

    Science.gov (United States)

    Zhu, Li; Zhong, Minghao; Elder, Gregory A; Sano, Mary; Holtzman, David M; Gandy, Sam; Cardozo, Christopher; Haroutunian, Vahram; Robakis, Nikolaos K; Cai, Dongming

    2015-09-22

    The apolipoprotein E4 (ApoE4) allele is the strongest genetic risk factor for developing sporadic Alzheimer's disease (AD). However, the mechanisms underlying the pathogenic nature of ApoE4 are not well understood. In this study, we have found that ApoE proteins are critical determinants of brain phospholipid homeostasis and that the ApoE4 isoform is dysfunctional in this process. We have found that the levels of phosphoinositol biphosphate (PIP2) are reduced in postmortem human brain tissues of ApoE4 carriers, in the brains of ApoE4 knock-in (KI) mice, and in primary neurons expressing ApoE4 alleles compared with those levels in ApoE3 counterparts. These changes are secondary to increased expression of a PIP2-degrading enzyme, the phosphoinositol phosphatase synaptojanin 1 (synj1), in ApoE4 carriers. Genetic reduction of synj1 in ApoE4 KI mouse models restores PIP2 levels and, more important, rescues AD-related cognitive deficits in these mice. Further studies indicate that ApoE4 behaves similar to ApoE null conditions, which fails to degrade synj1 mRNA efficiently, unlike ApoE3 does. These data suggest a loss of function of ApoE4 genotype. Together, our data uncover a previously unidentified mechanism that links ApoE4-induced phospholipid changes to the pathogenic nature of ApoE4 in AD.

  16. Distinct biophysical mechanisms of focal adhesion kinase mechanoactivation by different extracellular matrix proteins.

    Science.gov (United States)

    Seong, Jihye; Tajik, Arash; Sun, Jie; Guan, Jun-Lin; Humphries, Martin J; Craig, Susan E; Shekaran, Asha; García, Andrés J; Lu, Shaoying; Lin, Michael Z; Wang, Ning; Wang, Yingxiao

    2013-11-26

    Matrix mechanics controls cell fate by modulating the bonds between integrins and extracellular matrix (ECM) proteins. However, it remains unclear how fibronectin (FN), type 1 collagen, and their receptor integrin subtypes distinctly control force transmission to regulate focal adhesion kinase (FAK) activity, a crucial molecular signal governing cell adhesion/migration. Here we showed, using a genetically encoded FAK biosensor based on fluorescence resonance energy transfer, that FN-mediated FAK activation is dependent on the mechanical tension, which may expose its otherwise hidden FN synergy site to integrin α5. In sharp contrast, the ligation between the constitutively exposed binding motif of type 1 collagen and its receptor integrin α2 was surprisingly tension-independent to induce sufficient FAK activation. Although integrin α subunit determines mechanosensitivity, the ligation between α subunit and the ECM proteins converges at the integrin β1 activation to induce FAK activation. We further discovered that the interaction of the N-terminal protein 4.1/ezrin/redixin/moesin basic patch with phosphatidylinositol 4,5-biphosphate is crucial during cell adhesion to maintain the FAK activation from the inhibitory effect of nearby protein 4.1/ezrin/redixin/moesin acidic sites. Therefore, different ECM proteins either can transmit or can shield from mechanical forces to regulate cellular functions, with the accessibility of ECM binding motifs by their specific integrin α subunits determining the biophysical mechanisms of FAK activation during mechanotransduction.

  17. A proteomic approach to identify proteins from Trichuris trichiura extract with immunomodulatory effects.

    Science.gov (United States)

    Santos, L N; Gallo, M B C; Silva, E S; Figueiredo, C A V; Cooper, P J; Barreto, M L; Loureiro, S; Pontes-de-Carvalho, L C; Alcantara-Neves, N M

    2013-01-01

    Infections with Trichuris trichiura and other trichurid nematodes have been reported to display protective effects against atopy, allergic and autoimmune diseases. The aims of the present study were to investigate the immunomodulatory properties of T. trichiura adult worm extract (TtE) and its fractions (TtEFs) on the production of cytokines by peripheral blood mononuclear cells and to identify their proteinaceous components. Fourteen TtEFs were obtained by ion exchange chromatography and tested for effects on cytokine production by peripheral blood mononuclear cells. The molecular constituents of the six most active fractions were evaluated using nano-LC/mass spectrometry. The homology between T. trichiura and the related nematode Trichinella spiralis was used to identify 12 proteins in TtEFs. Among those identified, fructose biphosphate aldolase, a homologue of macrophage migration inhibitory factor and heat-shock protein 70 may contribute to the immunomodulatory effects of TtEFs. The identification of such proteins could lead to the development of novel drugs for the therapy of allergic and other inflammatory diseases.

  18. Phosphorylation-independent dual-site binding of the FHA domain of KIF13 mediates phosphoinositide transport via centaurin [alpha]1

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Yufeng; Tempel, Wolfram; Wang, Hui; Yamada, Kaori; Shen, Limin; Senisterra, Guillermo A.; MacKenzie, Farrell; Chishti, Athar H.; Park, Hee-Won (Toronto); (UICM)

    2011-11-07

    Phosphatidylinositol 3,4,5-triphosphate (PIP3) plays a key role in neuronal polarization and axon formation. PIP3-containing vesicles are transported to axon tips by the kinesin KIF13B via an adaptor protein, centaurin {alpha}1 (CENTA1). KIF13B interacts with CENTA1 through its forkhead-associated (FHA) domain. We solved the crystal structures of CENTA1 in ligand-free, KIF13B-FHA domain-bound, and PIP3 head group (IP4)-bound conformations, and the CENTA1/KIF13B-FHA/IP4 ternary complex. The first pleckstrin homology (PH) domain of CENTA1 specifically binds to PIP3, while the second binds to both PIP3 and phosphatidylinositol 3,4-biphosphate (PI(3,4)P2). The FHA domain of KIF13B interacts with the PH1 domain of one CENTA1 molecule and the ArfGAP domain of a second CENTA1 molecule in a threonine phosphorylation-independent fashion. We propose that full-length KIF13B and CENTA1 form heterotetramers that can bind four phosphoinositide molecules in the vesicle and transport it along the microtubule.

  19. Effect of the sesquiterpene lactone incomptine A in the energy metabolism of Entamoeba histolytica.

    Science.gov (United States)

    Velázquez-Domínguez, José; Marchat, Laurence A; López-Camarillo, Cesar; Mendoza-Hernández, Guillermo; Sánchez-Espíndola, Esther; Calzada, Fernando; Ortega-Hernández, Alfredo; Sánchez-Monroy, Virginia; Ramírez-Moreno, Esther

    2013-11-01

    Entamoeba histolytica is the causative agent of human amoebiasis, which mainly affects developing countries. Although several drugs are effective against E. histolytica trophozoites, the control of amoebiasis requires the development of new and better alternative therapies. Medicinal plants have been the source of new molecules with remarkable antiprotozoal activity. Incomptine A isolated from Decachaeta incompta leaves, is a sesquiterpene lactone of the heliangolide type which has the major in vitro activity against E. histolytica trophozoites. However the molecular mechanisms involved in its antiprotozoal activity are still unknown. Using a proteomic approach based on two-dimensional gel electrophoresis and mass spectrometry (ESI-MS/MS) analysis, we evidenced that 21 E. histolytica proteins were differentially expressed in response to incomptine A treatment. Notably, three glycolytic enzymes, namely enolase, pyruvate:ferredoxin oxidoreductase and fructose-1,6-biphosphate aldolase, were down-regulated. Moreover, ultrastructural analysis of trophozoites through electronic microscopy showed an increased number of glycogen granules. Taken together, our data suggested that incomptine A could affect E. histolytica growth through alteration of its energy metabolism.

  20. Chloride secretagogues stimulate inositol phosphate formation in shark rectal gland tubules cultured in suspension

    Energy Technology Data Exchange (ETDEWEB)

    Ecay, T.W.; Valentich, J.D. (Univ. of Texas Medical School, Houston (USA))

    1991-03-01

    Neuroendocrine activation of transepithelial chloride secretion by shark rectal gland cells is associated with increases in cellular cAMP, cGMP, and free calcium concentrations. We report here on the effects of several chloride secretagogues on inositol phosphate formation in cultured rectal gland tubules. Vasoactive intestinal peptide (VIP), atriopeptin (AP), and ionomycin increase the total inositol phosphate levels of cultured tubules, as measured by ion exchange chromatography. Forskolin, a potent chloride secretagogue, has no effect on inositol phosphate formation. The uptake of {sup 3}H-myo-inositol into phospholipids is very slow, preventing the detection of increased levels of inositol trisphosphate. However, significant increases in inositol monophosphate (IP1) and inositol biphosphate (IP2) were measured. The time course of VIP- and AP-stimulated IP1 and IP2 formation is similar to the effects of these agents on the short-circuit current responses of rectal gland monolayer cultures. In addition, aluminum fluoride, an artificial activator of guanine nucleotide-binding proteins, stimulates IP1 and IP2 formation. We conclude that rectal gland cells contain VIP and AP receptors coupled to the activation of phospholipase C. Coupling may be mediated by G-proteins. Receptor-stimulated increases in inositol phospholipid metabolism is one mechanism leading to increased intracellular free calcium concentrations, an important regulatory event in the activation of transepithelial chloride secretion by shark rectal gland epithelial cells.

  1. Ribulose Bisphosphate Carboxylase Activity in Anther-Derived Plants of Saintpaulia ionantha Wendl. Shag.

    Science.gov (United States)

    Bhaskaran, S; Smith, R H; Finer, J J

    1983-11-01

    Plants obtained from anther culture of the African violet, Saintpaulia ionantha Wendl. ;Shag' and vegetatively cloned copies of the parent anther donor plant were examined for their ploidy and ribulose-1,5-biphosphate carboxylase (RuBPcase) activity. The cloned parent plants were all diploid and did not vary much in their nuclear DNA, chlorophyll, and RuBPcase activity. Some of the anther-derived plants were similar to the parent plants while others were not. Different levels of ploidy were observed among the androgenetic plants. RuBPcase activities higher than that of the parent plants were found in some anther-derived plants. However, there was no direct correlation between ploidy and RuBPcase activity. Expression of nuclear genes from a single parent in the anther-derived plants and it's diploidization or plastid changes during early stages of microsporogenesis or androgenesis are suggested as possible reasons for the variations observed among them. This could be a useful technique to obtain physiological variants which could be agronomically desirable. PMID:16663273

  2. Immunization of broiler chickens against Clostridium perfringens-induced necrotic enteritis.

    Science.gov (United States)

    Kulkarni, R R; Parreira, V R; Sharif, S; Prescott, J F

    2007-09-01

    Necrotic enteritis (NE) in broiler chickens is caused by Clostridium perfringens. Currently, no vaccine against NE is available and immunity to NE is not well characterized. Our previous studies showed that immunity to NE followed oral infection by virulent rather than avirulent C. perfringens strains and identified immunogenic secreted proteins apparently uniquely produced by virulent C. perfringens isolates. These proteins were alpha-toxin, glyceraldehyde-3-phosphate dehydrogenase, pyruvate:ferredoxin oxidoreductase (PFOR), fructose 1,6-biphosphate aldolase, and a hypothetical protein (HP). The current study investigated the role of each of these proteins in conferring protection to broiler chickens against oral infection challenges of different severities with virulent C. perfringens. The genes encoding these proteins were cloned and purified as histidine-tagged recombinant proteins from Escherichia coli and were used to immunize broiler chickens intramuscularly. Serum and intestinal antibody responses were assessed by enzyme-linked immunosorbent assay. All proteins significantly protected broiler chickens against a relatively mild challenge. In addition, immunization with alpha-toxin, HP, and PFOR also offered significant protection against a more severe challenge. When the birds were primed with alpha-toxoid and boosted with active toxin, birds immunized with alpha-toxin were provided with the greatest protection against a severe challenge. The serum and intestinal washings from protected birds had high antigen-specific antibody titers. Thus, we conclude that there are certain secreted proteins, in addition to alpha-toxin, that are involved in immunity to NE in broiler chickens. PMID:17634510

  3. Short-term desensitization of G-protein-activated, inwardly rectifying K+ (GIRK) currents in pyramidal neurons of rat neocortex.

    Science.gov (United States)

    Sickmann, Thomas; Alzheimer, Christian

    2003-10-01

    Whole cell recordings from acutely isolated rat neocortical pyramidal cells were performed to study the kinetics and the mechanisms of short-term desensitization of G-protein-activated, inwardly rectifying K+ (GIRK) currents during prolonged application (5 min) of baclofen, adenosine, or serotonin. Most commonly, desensitization of GIRK currents was characterized by a biphasic time course with average time constants for fast and slow desensitization in the range of 8 and 120 s, respectively. The time constants were independent of the agonist used to evoke the current. The biphasic time course was preserved in perforated-patch recordings, indicating that neither component of desensitization is attributable to cell dialysis. Desensitization of GIRK currents displayed a strong heterologous component in that application of a second agonist substantially reduced the responsiveness to a test agonist. Fast desensitization, but not slow desensitization, was lost in cells loaded with GDP, suggesting that the hydrolysis cycle of G proteins might underlie the initial, rapid current decline. Hydrolysis of phosphatidylinositol biphosphate is an unlikely candidate underlying short-term desensitization, because both components of desensitization were preserved in the presence of the phospholipase C inhibitor U73122. We conclude that short-term desensitization does neither result from receptor downregulation nor from altered channel gating but might involve modifications of the G-protein-dependent pathway that serves to translate receptor activation into channel opening.

  4. Community structure of microorganisms associated with reddish-brown iron-rich snow.

    Science.gov (United States)

    Kojima, Hisaya; Fukuhara, Haruo; Fukui, Manabu

    2009-09-01

    Reddish-brown colored snow, containing spherical brown particles, has been observed in several mires in Japan. In order to characterize this remarkable phenomenon, the microbial community and chemical species in snow were analyzed. A core sample of snow which had a colored region was investigated and it revealed vertical shifts in physicochemical characteristics and the microbial community structure. The abundance of particles peaked within the colored layer, and correlated with the amount of reducible Fe(III). The interstitial water of the colored layer was enriched with Fe(II), and characterized by reduced concentration of dissolved methane. The bacterial community in the colored region was characterized by higher relative abundance of iron-reducing bacteria and methanotrophs. Aggregates of the brown particles were found as precipitates in snow melt pools, and were subjected to cloning analyses targeting several different genes. The majority of bacterial 16S rRNA gene clones belonged to the class Betaproteobacteria or the phylum Bacteroidetes. No snow algae were detected in the eukaryotic small subunit rRNA gene clone library. As a possible carbon source to sustain the community in the snow, involvements of carbon dioxide and methane were investigated by analyzing the genes involved in their assimilation. In the analyses of genes for ribulose-1,5-biphosphate carboxylase/oxygenase, clones related to sulfur oxidizers were obtained. The analysis of particulate methane monooxygenase genes indicated dominance of Methylobacter species. These results emphasized the uniqueness of this phenomenon, and iron reducers of the genus Geobacter are suggested to be the key organisms that could be investigated in order to understand the mechanism of this phenomenon. PMID:19560891

  5. Investigation of the Gracilaria gracilis (Gracilariales, Rhodophyta) proteome response to nitrogen limitation.

    Science.gov (United States)

    Naidoo, Rene K; Rafudeen, Muhammad S; Coyne, Vernon E

    2016-06-01

    Inorganic nitrogen has been identified as the major growth-limiting nutritional factor affecting Gracilaria gracilis populations in South Africa. Although the physiological mechanisms implemented by G. gracilis for adaption to low nitrogen environments have been investigated, little is known about the molecular mechanisms of these adaptions. This study provides the first investigation of G. gracilis proteome changes in response to nitrogen limitation and subsequent recovery. A differential proteomics approach employing two-dimensional gel electrophoresis and liquid chromatography-tandem mass spectrometry was used to investigate G. gracilis proteome changes in response to nitrogen limitation and recovery. The putative identity of 22 proteins that changed significantly (P < 0.05) in abundance in response to nitrogen limitation and recovery was determined. The identified proteins function in a range of biological processes including glycolysis, photosynthesis, ATP synthesis, galactose metabolism, protein-refolding and biosynthesis, nitrogen metabolism and cytoskeleton remodeling. The identity of fructose 1,6 biphosphate (FBP) aldolase was confirmed by western blot analysis and the decreased abundance of FBP aldolase observed with two-dimensional gel electrophoresis was validated by enzyme assays and western blots. The identification of key proteins and pathways involved in the G. gracilis nitrogen stress response provide a better understanding of G. gracilis proteome responses to varying degrees of nitrogen limitation and is the first step in the identification of biomarkers for monitoring the nitrogen status of cultivated G. gracilis populations.

  6. Tetraspanin CD82 inhibits protrusion and retraction in cell movement by attenuating the plasma membrane-dependent actin organization.

    Directory of Open Access Journals (Sweden)

    Wei M Liu

    Full Text Available To determine how tetraspanin KAI1/CD82, a tumor metastasis suppressor, inhibits cell migration, we assessed which cellular events critical for motility are altered by KAI1/CD82 and how KAI1/CD82 regulates these events. We found that KAI1/CD82-expressing cells typically exhibited elongated cellular tails and diminished lamellipodia. Live imaging demonstrated that the polarized protrusion and retraction of the plasma membrane became deficient upon KAI1/CD82 expression. The deficiency in developing these motility-related cellular events was caused by poor formations of actin cortical network and stress fiber and by aberrant dynamics in actin organization. Rac1 activity was reduced by KAI1/CD82, consistent with the diminution of lamellipodia and actin cortical network; while the growth factor-stimulated RhoA activity was blocked by KAI1/CD82, consistent with the loss of stress fiber and attenuation in cellular retraction. Upon KAI1/CD82 expression, Rac effector cofilin was not enriched at the cell periphery to facilitate lamellipodia formation while Rho kinase exhibited a significantly lower activity leading to less retraction. Phosphatidylinositol 4, 5-biphosphate, which initiates actin polymerization from the plasma membrane, became less detectable at the cell periphery in KAI1/CD82-expressing cells. Moreover, KAI1/CD82-induced phenotypes likely resulted from the suppression of multiple signaling pathways such as integrin and growth factor signaling. In summary, at the cellular level KAI1/CD82 inhibited polarized protrusion and retraction events by disrupting actin reorganization; at the molecular level, KAI1/CD82 deregulated Rac1, RhoA, and their effectors cofilin and Rho kinase by perturbing the plasma membrane lipids.

  7. Comparison of potential diatom 'barcode' genes (the 18S rRNA gene and ITS, COI, rbcL) and their effectiveness in discriminating and determining species taxonomy in the Bacillariophyta.

    Science.gov (United States)

    Guo, Liliang; Sui, Zhenghong; Zhang, Shu; Ren, Yuanyuan; Liu, Yuan

    2015-04-01

    Diatoms form an enormous group of photoautotrophic micro-eukaryotes and play a crucial role in marine ecology. In this study, we evaluated typical genes to determine whether they were effective at different levels of diatom clustering analysis to assess the potential of these regions for barcoding taxa. Our test genes included nuclear rRNA genes (the nuclear small-subunit rRNA gene and the 5.8S rRNA gene+ITS-2), a mitochondrial gene (cytochrome c-oxidase subunit 1, COI), a chloroplast gene [ribulose-1,5-biphosphate carboxylase/oxygenase large subunit (rbcL)] and the universal plastid amplicon (UPA). Calculated genetic divergence was highest for the internal transcribed spacer (ITS; 5.8S+ITS-2) (p-distance of 1.569, 85.84% parsimony-informative sites) and COI (6.084, 82.14%), followed by the 18S rRNA gene (0.139, 57.69%), rbcL (0.120, 42.01%) and UPA (0.050, 14.97%), which indicated that ITS and COI were highly divergent compared with the other tested genes, and that their nucleotide compositions were variable within the whole group of diatoms. Bayesian inference (BI) analysis showed that the phylogenetic trees generated from each gene clustered diatoms at different phylogenetic levels. The 18S rRNA gene was better than the other genes in clustering higher diatom taxa, and both the 18S rRNA gene and rbcL performed well in clustering some lower taxa. The COI region was able to barcode species of some genera within the Bacillariophyceae. ITS was a potential marker for DNA based-taxonomy and DNA barcoding of Thalassiosirales, while species of Cyclotella, Skeletonema and Stephanodiscus gathered in separate clades, and were paraphyletic with those of Thalassiosira. Finally, UPA was too conserved to serve as a diatom barcode.

  8. High frequency application of nanosecond pulsed electric fields alters cellular membrane disruption and fluorescent dye uptake

    Science.gov (United States)

    Steelman, Zachary A.; Tolstykh, Gleb P.; Beier, Hope T.; Ibey, Bennett L.

    2016-03-01

    Cells exposed to nanosecond-pulsed electric fields (nsPEF) exhibit a wide variety of nonspecific effects, including blebbing, swelling, intracellular calcium bursts, apoptotic and necrotic cell death, formation of nanopores, and depletion of phosphatidylinositol 4,5-biphosphate (PIP2) to induce activation of the inositol trisphosphate/diacylglycerol pathway. While several studies have taken place in which multiple pulses were delivered to cells, the effect of pulse repetition rate (PRR) is not well understood. To better understand the effects of PRR, a laser scanning confocal microscope was used to observe CHO-K1 cells exposed to ten 600ns, 200V pulses at varying repetition rates (5Hz up to 500KHz) in the presence of either FM 1-43, YO-PRO-1, or Propidium Iodide (PI) fluorescent dyes, probes frequently used to indicate nanoporation or permeabilization of the plasma membrane. Dye uptake was monitored for 30 seconds after pulse application at a rate of 1 image/second. In addition, a single long pulse of equivalent energy (200V, 6 μs duration) was applied to test the hypothesis that very fast PRR will approximate the biological effects of a single long pulse of equal energy. Upon examination of the data, we found strong variation in the relationship between PRR and uptake in each of the three dyes. In particular, PI uptake showed little frequency dependence, FM 1-43 showed a strong inverse relationship between frequency and internal cell fluorescence, and YO-PRO-1 exhibited a "threshold" point of around 50 KHz, after which the inverse trend observed in FM 1-43 was seen to reverse itself. Further, a very high PRR of 500 KHz only approximated the biological effects of a single 6 μs pulse in cells stained with YO-PRO-1, suggesting that uptake of different dyes may proceed by different physical mechanisms.

  9. Melanogenesis stimulation in B16-F10 melanoma cells induces cell cycle alterations, increased ROS levels and a differential expression of proteins as revealed by proteomic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Elizabeth S.; Kawahara, Rebeca [Departamento de Bioquimica e Biologia Molecular, Setor de Ciencias Biologicas, Universidade Federal do Parana, P.O. Box 19046, CEP 81531-990, Curitiba, PR (Brazil); Kadowaki, Marina K. [Universidade Estadual do Oeste do Parana, Cascavel, PR (Brazil); Amstalden, Hudson G.; Noleto, Guilhermina R.; Cadena, Silvia Maria S.C.; Winnischofer, Sheila M.B. [Departamento de Bioquimica e Biologia Molecular, Setor de Ciencias Biologicas, Universidade Federal do Parana, P.O. Box 19046, CEP 81531-990, Curitiba, PR (Brazil); Martinez, Glaucia R., E-mail: grmartinez@ufpr.br [Departamento de Bioquimica e Biologia Molecular, Setor de Ciencias Biologicas, Universidade Federal do Parana, P.O. Box 19046, CEP 81531-990, Curitiba, PR (Brazil)

    2012-09-10

    Considering that stimulation of melanogenesis may lead to alterations of cellular responses, besides melanin production, our main goal was to study the cellular effects of melanogenesis stimulation of B16-F10 melanoma cells. Our results show increased levels of the reactive oxygen species after 15 h of melanogenesis stimulation. Following 48 h of melanogenesis stimulation, proliferation was inhibited (by induction of cell cycle arrest in the G1 phase) and the expression levels of p21 mRNA were increased. In addition, melanogenesis stimulation did not induce cellular senescence. Proteomic analysis demonstrated the involvement of proteins from other pathways besides those related to the cell cycle, including protein disulfide isomerase A3, heat-shock protein 70, and fructose biphosphate aldolase A (all up-regulated), and lactate dehydrogenase (down-regulated). In RT-qPCR experiments, the levels of pyruvate kinase M2 mRNA dropped, whereas the levels of ATP synthase (beta-F1) mRNA increased. These data indicate that melanogenesis stimulation of B16-F10 cells leads to alterations in metabolism and cell cycle progression that may contribute to an induction of cell quiescence, which may provide a mechanism of resistance against cellular injury promoted by melanin synthesis. -- Highlights: Black-Right-Pointing-Pointer Melanogenesis stimulation by L-tyrosine+NH{sub 4}Cl in B16-F10 melanoma cells increases ROS levels. Black-Right-Pointing-Pointer Melanogenesis inhibits cell proliferation, and induced cell cycle arrest in the G1 phase. Black-Right-Pointing-Pointer Proteomic analysis showed alterations in proteins of the cell cycle and glucose metabolism. Black-Right-Pointing-Pointer RT-qPCR analysis confirmed alterations of metabolic targets after melanogenesis stimulation.

  10. Metabolic scaling theory in plant biology and the three oxygen paradoxa of aerobic life.

    Science.gov (United States)

    Kutschera, Ulrich; Niklas, Karl J

    2013-12-01

    Alfred Russell Wallace was a field naturalist with a strong interest in general physiology. In this vein, he wrote that oxygen (O2), produced by green plants, is "the food of protoplasm, without which it cannot continue to live". Here we summarize current models relating body size to respiration rates (in the context of the metabolic scaling theory) and show that oxygen-uptake activities, measured at 21 vol.% O2, correlate closely with growth patterns at the level of specific organs within the same plant. Thus, whole plant respiration can change ontogenetically, corresponding to alterations in the volume fractions of different tissues. Then, we describe the evolution of cyanobacterial photosynthesis during the Paleoarchean, which changed the world forever. By slowly converting what was once a reducing atmosphere to an oxidizing one, microbes capable of O2-producing photosynthesis modified the chemical nature and distribution of the element iron (Fe), slowly drove some of the most ancient prokaryotes to extinction, created the ozone (O3) layer that subsequently shielded the first terrestrial plants and animals from harmful UV radiation, but also made it possible for Earth's forest to burn, sometimes with catastrophic consequences. Yet another paradox is that the most abundant protein (i.e., the enzyme Rubisco, Ribulose-1,5-biphosphate carboxylase/oxygenase) has a greater affinity for oxygen than for carbon dioxide (CO2), even though its function is to bind with the latter rather than the former. We evaluate this second "oxygen paradox" within the context of photorespiratory carbon loss and crop yield reduction in C3 vs. C4 plants (rye vs. maize). Finally, we analyze the occurrence of reactive oxygen species (ROS) as destructive by-products of cellular metabolism, and discuss the three "O2-paradoxa" with reference to A. R. Wallace's speculations on "design in nature".

  11. Comparison of Activities and Properties of Pyrophosphate and Adenosine Triphosphate-Dependent Phosphofructokinases of Black Gram (Phaseolus mungo) Seeds.

    Science.gov (United States)

    Ashihara, H; Stupavska, S

    1984-09-01

    Both pyrophosphate-dependent phosphofructokinase (PPi-PFKase, EC 2.7.1.90) and ATPdependent phosphofructokinase (ATP-PFKase, EC 2.7. 1.11) were present in dry and germinated black gram seeds. In the absence of fructose-2,6-biphosphate (F2,6BP), the activity of PPi-PFKase expressed as nmol · min(-1) · (pair of cotyledons)(-1) was much lower than that of ATP-PFKase in both dry and germinated seeds. However, PPi-PFKase was activated by F2,6BP and its activity reached the same level as ATP-PFKase activity. ATP-PFKase showed sigmoidal kinetics respective to fructose-6-phosphate (F6P), while PPi-PFKase exhibited hyperbolic kinetics in the presence of F2,6BP. The F6P concentration for half maximal activity of ATP-PFKase (1.5 mM) was nearly 5 times lower than that of PPi-PFKase (7.1 mM). The apparent Km values of PPi-PFKase for PPi and that of ATP-PFKase for ATP were 0.29 mM and 0.23 mM, respectively. Phosphoenolpyruvate (PEP) and citrate inhibited ATP-PFKase activity, but they did not affect PPi-PFKase activity. The activity of PPi-PFKase was inhibited by Pi, while only a little Pi inhibition was observed in the case of ATP-PFKase. These results suggest that the control mechanism of PPi-PFKase and that of ATP-PFKase are quite different. In contrast to pineapple leaves (Carnal, N. W. and C. C. Black, Biochem. Biophys. Res. Commun. 86, 20-26, 1979) and caster bean seedlings (Krugar et al., FEBS Lett. 153, 409-412, 1983), PPi-PFKase is not the predominant PFKase activity in black gram seeds.

  12. Differential protein expression profile in the liver of pikeperch (Sander lucioperca) larvae fed with increasing levels of phospholipids.

    Science.gov (United States)

    Hamza, Neïla; Silvestre, Frédéric; Mhetli, Mohamed; Khemis, Ines Ben; Dieu, Marc; Raes, Martine; Cahu, Chantal; Kestemont, Patrick

    2010-06-01

    A comparative proteomic approach was used to assess the protein expression profile in the liver of 34days old pikeperch larvae fed from day 10 post hatching, with three isoproteic and isolipidic formulated diets varying by their phospholipid (PL) contents (% dry diet weight): 1.4% (PL1), 4.7% (PL5) and 9.5% (PL9). Using 2D-DIGE minimal labelling of liver extracts, we were able to show 56 protein spots with a differential intensity (pproteins were unambiguously identified using nanoLC-MS/MS tandem mass spectrometry. In the PL9 larvae, our results indicate that the glycolytic pathway could be down-regulated due to the under-expression of the fructose biphosphate aldolase B and the phosphoglucomutase 1. Meanwhile, propionyl coenzyme A carboxylase (a gluconeogenic enzyme) was under-expressed. In addition, another gluconeogenic and lipogenic enzyme, pyruvate carboxylase, was identified in 3 different spots as being under-expressed in fish fed with the intermediate PL level (PL5). A high PL content increased the expression of sarcosine dehydrogenase, an enzyme involved in methionine metabolism, along with vinculin, a structural protein. Moreover, several stress proteins (glutathione S-transferase M, glucose regulated protein 75 and peroxiredoxin-1) were modulated in response to the dietary PL level and fatty acid composition. In the larvae fed with the lowest dietary PL content (PL1), over-expression of both GSTM and GRP75 might indicate a cellular stress in this experimental treatment, while the under-expression of Prx1 might indicate a lower defence against oxidative stress. In conclusion, this nutriproteomic approach showed significant modifications of protein expression in the liver of pikeperch larvae fed different PL contents, highlighting the importance of these nutrients and their influence on metabolism processes and on stress response.

  13. Lab scale testing of novel natural analog in situ stabilization agents

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, P. [Lockheed Martin Idaho Technology Co., Idaho Falls, ID (United States)

    1997-12-31

    This report summarizes the laboratory-scale test results on several novel in situ treatment and stabilization agents for buried hazardous and radioactive waste. Paraffin, hematite and phosphate materials were examined when combined with soil and other wastes representative of what might be present at buried waste DOE sites. Hematite was made from the reaction of agricultural iron and lime slurries to form gypsum and iron oxide/hydroxide. Common household paraffin was melted, both with and without a zeolitic additive, waste added and then cooled. Magnesium phosphate was made from the reaction of magnesium oxide and phosphoric acid or potassium biphosphate to form, magnesium phosphate. All were tested with soil and some with additional waste sumulants such as ash, machine oil and nitrate salts. The following laboratory-generated data indicate that all waste encapsulation materials tested are appropriate materials, for field in situ testing. Compressive strengths of treated Idaho National Engineering and Environment Laboratory (INEEL) soil and the waste encapsulation material were sufficient to prevent collapse of the void space in waste, i.e., greater than the NRC 60 psi minimum. The mineralogy and microstructure of hematite was amorphous but should progress to an interlocking crystalline solid. Phosphate was crystalline with characteristics of higher temperature ceramics. Paraffin is non crystalline but encapsulates even very fine grained INEEL soils. Each agent appears to be chemically and physically inert to possible waste materials such as, nitrates and machine cutting oil. Two of the agents hematite and phosphate react favorably with ash increasing the metals retention at higher waste loadings than Portland cement. Hematite, phosphate and zeolite decrease leaching of most hazardous metals from waste when compared to untreated waste and soil. Solution pH, time for reaction initiation, and viscosity values are conducive to jet-grouting application.

  14. Ecophysiological responses and carbon distribution of Pinus koraiensis seedlings to elevated carbon dioxide

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The net CO2 assimilation rate, stomatal conductance, RuBPcase (ribulose 1,5-biphosphate carboxylose) activity, dry weight of aboveground and belowground part, plant height, the length and diameter of taproot of Pinus koraiensis seedlings were measured and analyzed after six-week exposure to elevated CO2 in an open-top chamber in Changbai Mountain of China from May to Oct. 1999. Seedlings were planted in four different conditions: on an open site, control chamber, 500 μ L.L-1 and 700 μL.L-1 CO2 chambers. The results showed that the total biomass of the seedlings increased whereas stomatal conductance decreased. The physiological responses and growth to 500 μL.L-1 and 700 μ L.L-1 CO2 varied greatly. The acclimation of photosynthesis was downward to 700 μL.L-1 CO2 but upward to 500 μ L.L-1 CO2. The RuBPcase activity, chlorophyll and soluble sugar contents of the seedlings grown at 500 μL.L-1 CO2 were higher than that at 700 μ L.L-1 CO2. The concentration 500 μ L.L-1 CO2 enhanced the growth of aboveground part whereas 700 μL.L-1 CO2 allocated more carbon to belowground part. Elevated CO2 changed the carbon distribution pattern. The ecophysiological responses were significantly different between plants grown under 500 μL.L-1 CO2 and 700 μL.L-1 CO2.

  15. Structure and Bioactivity of Hydroxyapatite Coatings on Pure Titanium Fabricated by Microarc Oxidation%钛表面微弧氧化羟基磷灰石陶瓷膜的结构及其生物活性

    Institute of Scientific and Technical Information of China (English)

    于维先; 刘歆婵; 王闻天; 张玉凤; 王海瑞

    2014-01-01

    Porous hydroxyapatite (HA )ceramic coating on pure titanium (TA2 ) substrate was fabricated by microarc oxidation (MAO ) in electrolytic solution containing calcium acetate monohydrate and sodium biphosphate dihydrate salt.The morphology,phase and composition of the coating were characterized by scanning electron microscopy (SEM),X-ray diffraction (XRD),energy dispersive X-ray spectrometry (EDS)and Fourier transmission infrared spectrometry (FT-IR).The bioactivity of the HA ceramic coating was investigated by simulated body fluid (SBF)tests invitro. The result shows that the ceramic coating was formed on pure titanium substrate,and hydroxyapatite phase was found in the ceramic coating after the microarc oxidation for 10 min.Moreover,HA ceramic coating was proved to be of excellent bioactivity from the carbonate-containing HA formation on the ceramic coating surfaces.The coatings of MAO are covered completely by the carbonate-containing HA ceramic coatings after 48 h exposure to simulated body fluid.%采用微弧氧化技术(MAO),以纯钛(TA2)为基体,在醋酸钙和磷酸二氢钠电解液体系中,制备含羟基磷灰石(H A)的生物活性陶瓷膜,并利用扫描电子显微镜(SEM)、X 射线衍射(XRD)、X射线能谱(EDS)和红外光谱(FT-IR)对膜层进行表征,通过体外模拟体液浸泡实验检测膜层的生物活性。结果表明,纯钛经微弧氧化处理10 min后,在其表面能生成一层含羟基磷灰石成分的多孔陶瓷膜,该膜层经模拟体液浸泡48 h 后,其表面覆盖一层含有CO2-3的羟基磷灰石(类骨磷灰石),即该陶瓷膜层具有良好的生物活性。

  16. Oculocerebrorenal syndrome of Lowe: magnetic resonance imaging findings in the first six years of life

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho-Neto, Arnolfo de; Ono, Sergio Eiji; Cardoso, Georgina de Melo; Santos, Mara Lucia Schmitz Ferreira; Celidonio, Izabela [Hospital Pequeno Principe, Curitiba, PR (Brazil)], e-mail: ono.sergio@gmail.com

    2009-06-15

    The oculocerebrorenal syndrome of Lowe (OCRL), was first recognized as a distinct disease in 1952 by Drs. Lowe, Terrey and MacLachlan at Massachusetts General Hospital, in Boston, USA, describing three male children with organic aciduria, decreased renal ammonia production, hydrophtalmos and mental retardation. The X-linked recessive inheritance pattern was recognized first by LeFebvre. It is present in all races, with a predominance in those of Caucasian and Asian ancestries. Rarely females are affected. It is a very rare disease, with estimated prevalence in the general population of 1 in 500,000. In USA the Lowe Syndrome Association (LSA) documented 190 living patients in the year 2000 (0.67 x million inhabitants). It is caused by a mutation in the gene encoding oculocerebrorenal- Lowe protein (OCRL1), isolated in 1992, linked to the Xq24-q26 region of the X chromosome,4-6. Approximately 60% of OCRL patients demonstrate a loss of OCRL gene expression, and the definitive laboratory test, that can be used for prenatal diagnosis, is the biochemical assay for deficiency of phosphatidylinositol 4,5-biphosphate 5-phosphate in cultured fibroblasts. The classic triad of eye, central nervous system, and kidney involvement are required for the diagnosis of Lowe's syndrome. Cataract is present at birth in all patients and glaucoma is detected within the first year of life. Hypotonia compromises suction and causes serious respiratory problems in the first period of life. Motor development is retarded and mental retardation is moderate or severe in almost all cases. Obsessive-compulsive behavior is typical. Seizure is seen in approximately 50% of the patients over 18 years old. Renal disease is primarily characterized by renal Fanconi syndrome but many children are asymptomatic at birth. Renal involvement is initially related to bicarbonate, salt and water wasting, causing failure to thrive. Later, a significant number of patients develop chronic renal failure. The

  17. Molecular evolution of rbcL in three gymnosperm families: identifying adaptive and coevolutionary patterns

    LENUS (Irish Health Repository)

    Sen, Lin

    2011-06-03

    Abstract Background The chloroplast-localized ribulose-1, 5-biphosphate carboxylase\\/oxygenase (Rubisco), the primary enzyme responsible for autotrophy, is instrumental in the continual adaptation of plants to variations in the concentrations of CO2. The large subunit (LSU) of Rubisco is encoded by the chloroplast rbcL gene. Although adaptive processes have been previously identified at this gene, characterizing the relationships between the mutational dynamics at the protein level may yield clues on the biological meaning of such adaptive processes. The role of such coevolutionary dynamics in the continual fine-tuning of RbcL remains obscure. Results We used the timescale and phylogenetic analyses to investigate and search for processes of adaptive evolution in rbcL gene in three gymnosperm families, namely Podocarpaceae, Taxaceae and Cephalotaxaceae. To understand the relationships between regions identified as having evolved under adaptive evolution, we performed coevolutionary analyses using the software CAPS. Importantly, adaptive processes were identified at amino acid sites located on the contact regions among the Rubisco subunits and on the interface between Rubisco and its activase. Adaptive amino acid replacements at these regions may have optimized the holoenzyme activity. This hypothesis was pinpointed by evidence originated from our analysis of coevolution that supported the correlated evolution between Rubisco and its activase. Interestingly, the correlated adaptive processes between both these proteins have paralleled the geological variation history of the concentration of atmospheric CO2. Conclusions The gene rbcL has experienced bursts of adaptations in response to the changing concentration of CO2 in the atmosphere. These adaptations have emerged as a result of a continuous dynamic of mutations, many of which may have involved innovation of functional Rubisco features. Analysis of the protein structure and the functional implications of such

  18. Brindley Manor Private Nursing Home, Letterkenny Road, Convoy, Donegal

    LENUS (Irish Health Repository)

    Sen, Lin

    2011-06-03

    Abstract Background The chloroplast-localized ribulose-1, 5-biphosphate carboxylase\\/oxygenase (Rubisco), the primary enzyme responsible for autotrophy, is instrumental in the continual adaptation of plants to variations in the concentrations of CO2. The large subunit (LSU) of Rubisco is encoded by the chloroplast rbcL gene. Although adaptive processes have been previously identified at this gene, characterizing the relationships between the mutational dynamics at the protein level may yield clues on the biological meaning of such adaptive processes. The role of such coevolutionary dynamics in the continual fine-tuning of RbcL remains obscure. Results We used the timescale and phylogenetic analyses to investigate and search for processes of adaptive evolution in rbcL gene in three gymnosperm families, namely Podocarpaceae, Taxaceae and Cephalotaxaceae. To understand the relationships between regions identified as having evolved under adaptive evolution, we performed coevolutionary analyses using the software CAPS. Importantly, adaptive processes were identified at amino acid sites located on the contact regions among the Rubisco subunits and on the interface between Rubisco and its activase. Adaptive amino acid replacements at these regions may have optimized the holoenzyme activity. This hypothesis was pinpointed by evidence originated from our analysis of coevolution that supported the correlated evolution between Rubisco and its activase. Interestingly, the correlated adaptive processes between both these proteins have paralleled the geological variation history of the concentration of atmospheric CO2. Conclusions The gene rbcL has experienced bursts of adaptations in response to the changing concentration of CO2 in the atmosphere. These adaptations have emerged as a result of a continuous dynamic of mutations, many of which may have involved innovation of functional Rubisco features. Analysis of the protein structure and the functional implications of such

  19. Probing vaccine antigens against bovine mastitis caused by Streptococcus uberis.

    Science.gov (United States)

    Collado, Rosa; Prenafeta, Antoni; González-González, Luis; Pérez-Pons, Josep Antoni; Sitjà, Marta

    2016-07-19

    Streptococcus uberis is a worldwide pathogen that causes intramammary infections in dairy cattle. Because virulence factors determining the pathogenicity of S. uberis have not been clearly identified so far, a commercial vaccine is not yet available. Different S. uberis strains have the ability to form biofilm in vitro, although the association of this kind of growth with the development of mastitis is unknown. The objective of this study was to evaluate the potential use as vaccine antigens of proteins from S. uberis biofilms, previously identified by proteomic and immunological analyses. The capability of eliciting a protective immune response by targeted candidates was assayed on a murine model. Sera from rabbits immunized with S. uberis biofilm preparations and a convalescent cow intra-mammary infected with S. uberis were probed against cell wall proteins from biofilm and planktonic cells previously separated by two-dimensional gel electrophoresis. Using rabbit immunized serum, two proteins were found to be up-regulated in biofilm cells as compared to planktonic cells; when serum from the convalescent cow was used, up to sixteen biofilm proteins were detected. From these proteins, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), fructose-biphosphate aldolase (FBA), and elongation factor Ts (EFTs) were chosen to be tested as vaccine antigen candidates. For this purpose, different groups of mice were immunized with the three recombinant-expressed proteins (each one formulated separately in a vaccine), and thereafter intraperitoneally challenged with S. uberis. The three proteins induced specific IgG antibodies, but a significant reduction of mortality was only observed in the groups of mice vaccinated with FBA or EFTs. These results suggest that FBA and EFTs might be considered as strong antigenic candidates for a vaccine against S. uberis bovine mastitis. Moreover, this is the first study to indicate that also in S. uberis, GAPDH, FBA and EFTs, as proteins

  20. Molybdate:sulfate ratio affects redox metabolism and viability of the dinoflagellate Lingulodinium polyedrum

    Energy Technology Data Exchange (ETDEWEB)

    Barros, M.P., E-mail: marcelo.barros@cruzeirodosul.edu.br [Postgraduate Program in Health Science (Environmental Chemistry), CBS, Universidade Cruzeiro do Sul, 08060070 São Paulo, SP (Brazil); Hollnagel, H.C. [Pós-Graduação, Faculdade Mario Schenberg, 06710500 Cotia, SP (Brazil); Glavina, A.B. [Postgraduate Program in Health Science (Environmental Chemistry), CBS, Universidade Cruzeiro do Sul, 08060070 São Paulo, SP (Brazil); Soares, C.O. [Postgraduate Program in Health Science (Environmental Chemistry), CBS, Universidade Cruzeiro do Sul, 08060070 São Paulo, SP (Brazil); Department of Biochemistry, Instituto de Química, Universidade de São Paulo (IQ-USP), São Paulo (Brazil); Ganini, D. [Postgraduate Program in Health Science (Environmental Chemistry), CBS, Universidade Cruzeiro do Sul, 08060070 São Paulo, SP (Brazil); Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709 (United States); Dagenais-Bellefeuille, S.; Morse, D. [Departement de Sciences Biologiques, Institut de Recherche en Biologie Végétale, Université de Montréal, Montreal, QC H1X 2B2 (Canada); Colepicolo, P. [Department of Biochemistry, Instituto de Química, Universidade de São Paulo (IQ-USP), São Paulo (Brazil)

    2013-10-15

    the three major antioxidant enzymes (superoxide dismutase, catalase, and ascorbate peroxidase), indexes of oxidative modifications in proteins (carbonyl content) and lipids (thiobarbituric acid-reactive substances, TBARS), the activities of the molybdenum-dependent enzymes xanthine oxidase and nitrate reductase, expression of key protein components of dinoflagellate photosynthesis (peridinin–chlorophyll a protein and ribulose-1,5-biphosphate carboxylase/oxidase) and growth curves. We find evidence for Mo toxicity at relatively high [MoO{sub 4}{sup 2−}]:[SO{sub 4}{sup 2−}] ratios. We also find evidence for extensive redox adaptations at Mo levels well below lethal levels.

  1. Probing vaccine antigens against bovine mastitis caused by Streptococcus uberis.

    Science.gov (United States)

    Collado, Rosa; Prenafeta, Antoni; González-González, Luis; Pérez-Pons, Josep Antoni; Sitjà, Marta

    2016-07-19

    Streptococcus uberis is a worldwide pathogen that causes intramammary infections in dairy cattle. Because virulence factors determining the pathogenicity of S. uberis have not been clearly identified so far, a commercial vaccine is not yet available. Different S. uberis strains have the ability to form biofilm in vitro, although the association of this kind of growth with the development of mastitis is unknown. The objective of this study was to evaluate the potential use as vaccine antigens of proteins from S. uberis biofilms, previously identified by proteomic and immunological analyses. The capability of eliciting a protective immune response by targeted candidates was assayed on a murine model. Sera from rabbits immunized with S. uberis biofilm preparations and a convalescent cow intra-mammary infected with S. uberis were probed against cell wall proteins from biofilm and planktonic cells previously separated by two-dimensional gel electrophoresis. Using rabbit immunized serum, two proteins were found to be up-regulated in biofilm cells as compared to planktonic cells; when serum from the convalescent cow was used, up to sixteen biofilm proteins were detected. From these proteins, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), fructose-biphosphate aldolase (FBA), and elongation factor Ts (EFTs) were chosen to be tested as vaccine antigen candidates. For this purpose, different groups of mice were immunized with the three recombinant-expressed proteins (each one formulated separately in a vaccine), and thereafter intraperitoneally challenged with S. uberis. The three proteins induced specific IgG antibodies, but a significant reduction of mortality was only observed in the groups of mice vaccinated with FBA or EFTs. These results suggest that FBA and EFTs might be considered as strong antigenic candidates for a vaccine against S. uberis bovine mastitis. Moreover, this is the first study to indicate that also in S. uberis, GAPDH, FBA and EFTs, as proteins

  2. 钙肥对春甜桔产量和品质的影响%Effect of calcium fertilizer on the fruit yield and quality of Chuntian tangerine

    Institute of Scientific and Technical Information of China (English)

    陈桂芬; 黄玉溢; 熊柳梅; 刘斌; 刘永贤

    2013-01-01

    [目的]探讨施用不同钙肥对柑桔裂果、产量和品质的影响,为钙肥在柑桔生产中的合理应用提供理论依据.[方法]试验设5个处理(不施钙肥作对照,其余分别施用乙酸钙、硝酸钙、磷酸二氢钙、石灰).乙酸钙、硝酸钙、磷酸二氢钙按等量钙设计采用叶面喷施;石灰采用土施,施用量为1.5 kg/株,均在柑桔果实膨大初期施用.在裂果高峰期调查裂果情况,果实成熟时测定各处理的果实产量,分析果实的品质.[结果]与不施钙相比,施用不同钙肥均能明显减少柑桔的裂果数量,提高单果重和果实产量,增产效果从高到低依次是石灰>乙酸钙>磷酸二氢钙>硝酸钙,增产率分别为22.43%、18.75%、15.09%、13.24%,施用钙肥还可降低果实的酸度,果实的糖酸比提高125.0%~ 186.5%,同时可提高果实维生素C的含量和果皮钙的含量,降低贮藏期的烂果率.[结论]施用钙肥对柑桔果实产量和品质具有明显的促进作用,既能提高产量,又能改善品质.%[Objective]In order to provide scientific basis for using calcium fertilizer in Chuntian tangerines, the present study was conducted to examine the effect of different calcium fertilizers on fruit cracking, fruit yield, and fruit quality of Chuntian tangerine. [Method]Five experimental treatments were set: treatment 1: no fertilization treatment as control; treatment 2: calcium acetate application treatment; treatment 3: calcium nitrate application treatment; treatment 4: calcium biphosphate application treatment; treatment 5: liming application. The calcium acetate, calcium nitrate, and calcium biphosphate fertilizers were applied by foliar spraying, while the liming application was applied by soil application. The foliar spaying fertilizer was designed according to the same amount of calcium. The liming application rate was 1.5 kg/plant, and the appropriate application time was during early fruit enlargement stage

  3. Determination of plasma concentration of lamotrigine in epilepsy patients by RP-HPLC%高效液相色谱法测定癫痫患者血浆中拉莫三嗪的浓度

    Institute of Scientific and Technical Information of China (English)

    刘立民; 刘美; 朱旭; 孙亚欣; 何晓静; 邱枫; 肇丽梅

    2013-01-01

    OBJECTIVE To develop an HPLC method for the determination of lamotrigine in human plasma METHODS With chiorzoxazone as internal standard, the plasma was extracted with diethyl ether. The analysis was conducted on a C18 column. The flow rate was 1. 0 mL·min-1 and the column temperature was 25 ℃. The detecting wavelength was set at 220 nm. The mobile phase consisted of acetonitrile-0. 05 mol·L-1 biphosphate sodium(v/v,26. 5:73. 5,pH 4. 5). RESULTS The linear range of lamotrigine was 0. 5 - 30 μg·mL-1 (r= 0. 991 1) and the detection limit was 0. 5 μg·mL-1 . The range of extraction recovery ratio was 90. 00% - 93. 75%. The intra-and inter-day precision was both less than 15%. The concentration range of lamotrigine in 25 epilepsy patients was 0. 5 - 10. 2 μg·mL-1 , which fluctuated more widely compared with the recommended concentration. The relationship between lamotrigine plasma concentration and daily doses (0. 5 - 3. 8 mg·kg-1·d-1) was linear. The range of the lamotrigine concentration to dose ratio was 0. 8 - 5. 1 μg·mL-1. CONCLUSION The method is simple, accurate, sensitive, which is suitable for the study of therapeutic drug concentration monitoring of lamotrigine.%目的:建立测定血浆中拉莫三嗪浓度的高效液相色谱方法.方法:以氯唑沙宗为内标,血浆样品用乙醚萃取,采用C18柱(4.6 mm×250 mm,5 μm)分析.流动相为乙腈-0.05 mol·L-1磷酸二氢钠溶液(v/v,26.5:73.5,pH 4.5),流速为1.0mL·min-1,检测波长220 nm,柱温25℃.结果:拉莫三嗪浓度在0.5~30 μg·mL-1范围内线性关系良好,r=0.9911,定量下限为0.5 μg·mL-1,提取回收率在90.00%~93.75%,日内、日间RSD均<15%.25例癫痫患者拉莫三嗪血药浓度范围为0.5~10.2 μg·mL-1,与推荐的拉莫三嗪有效治疗浓度相比波动较大,标准化血药浓度为0.8~5.1 μg·mL-1,拉莫三嗪血药浓度与日剂量(0.5~3.8 mg·kg-1·d-1)线性相关.结论:该方法简便、准确、灵敏度高、回收率及精

  4. Engineering and Coordination of Regulatory Networks and Intracellular Complexes to Maximize Hydrogen Production by Phototrophic Microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    James C. Liao

    2012-05-22

    reductive pentose phosphate pathway, whose key enzyme is ribulose 1,5-biphosphate carboxylase/oxygenase (RubisCO). In addition to providing virtually all cellular carbon during autotrophic metabolism, RubisCO-mediated CO{sub 2} assimilation is also very important for nonsulfur purple photosynthetic bacteria under photoheterotrophic growth conditions since CO{sub 2} becomes the major electron sink under these conditions. In this work, Ensemble Modeling (EM) was developed to examine the behavior of CBB-compromised RubisCO knockout mutant strains of the nonsulfur purple photosynthetic bacterium Rhodobacter sphaeroides. Mathematical models of metabolism can be a great aid in studying the effects of large perturbations to the system, such as the inactivation of RubisCO. Due to the complex and highly-interconnected nature of these networks, it is not a trivial process to understand what the effect of perturbations to the metabolic network will be, or vice versa, what enzymatic perturbations are necessary to yield a desired effect. Flux distribution is controlled by multiple enzymes in the network, often indirectly linked to the pathways of interest. Further, depending on the state of the cell and the environmental conditions, the effect of a perturbation may center around how it effects the carbon flow in the network, the balancing of cofactors, or both. Thus, it is desirable to develop mathematical models to describe, understand, and predict network behavior. Through the development of such models, one may gain the ability to generate a set of testable hypotheses for system behavior.

  5. A role for inositol 1,4,5-trisphosphate in the initiation of agonist-induced contractions of dog tracheal smooth muscle.

    Science.gov (United States)

    Hashimoto, T; Hirata, M; Ito, Y

    1985-09-01

    To elucidate the role of inositol 1,4,5-trisphosphate (Ins-P3) in the initiation of agonist-induced contraction of the smooth muscle cells of the dog trachea, we investigated the effects of acetylcholine (ACh) on the concentrations of Ins-P3, phosphatidylinositol-4,5-bisphosphate (PI-P2) or phosphatidic acid (PA). The effects of Ins-P3 on the Ca2+ stored in the smooth muscle cells were also studied in saponin-permeabilized smooth muscle cells. A half maximal or maximal Ca2+ accumulation into the cells was observed in the dispersed single, smooth muscle cells treated by saponin, in free Ca2+ concentrations of 4.6 X 10(-7) or 5 X 10(-5)M, respectively. The ATP-dependent Ca2+ accumulation was maximal at 0.63 nmol/10(5) cells. Effects of Ins-P3 on stored Ca2+ were observed at a free Ca2+ concentration of 3.7 X 10(-7)M, which induces about half maximal ATP-dependent Ca2+-accumulation. Ins-P3 released the Ca2+ accumulated by ATP, in a dose-dependent manner. About 40% of the total Ca2+ was released following application of 3 microM Ins-P3. The release of stored Ca2+ induced by application of Ins-P3 was followed by its re-uptake into the smooth muscle cells. Thus, the stored Ca2+ was repeatedly released with repetitive applications of Ins-P3. Application of ACh (10(-5)M) to the dog trachea stimulated the production of Ins-P3 in the soluble fraction and 10s after this application, the relative amount of Ins-P3 was 290% of the control value. 6 Concomitantly, ACh (10- 5 M) either reduced or increased the contents ofphosphatidyl inositol 4,5-biphosphate (PI-P2) or phosphatidic acid (PA) in the lipid fraction ofthe smooth muscle cells to 60% or to 350% of the control value, respectively, thereby indicating that ACh stimulates the phosphodiesteric hydrolysis of PI-P2. 7 5-Hydroxytryptamine (5-HT; 10- 5M) also reduced or increased the contents of PI-P2 or PA to 80 or to 200% of the control values, respectively. However, neither histamine (10-5M), in the presence or absence of

  6. The new research on tumor suppressor gene in hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    JI Yu-bin; YANG Hai-fan; YU Lei; PANG lin-lin; LI Hai-jiao; LIU Guang-da

    2008-01-01

    Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death in the world. The carcinogenesis of HCC is multifactorial, multifunctional and multistage. Tumor suppressor gene therapy is one of the strategies, it is mainly used to make use of tumor suppressor gene groups which can inhibit the cell growth, to prevent the expression of oncogenes or to resume the function of anti-oncogenes. But so far, there is not a particular gene to be a main tumor suppressor gene in HCC. Therefore, it is necessary to study on the new anti-oncogenes to explain pathogenesis of liver cancer and seek for the newly effective target to carry on liver cancer gene therapy. PTEN (phosphatase and tensin homolog deleted on chromosome ten) was discovered as a tumor suppressor gene. It functions as a protein tyrosine phosphatase and as a lipid phosphatase. As a lipid phosphatase, PTEN antagonizes PI3K/Akt signaling by dephosphorylating the D3 position of the inositol ring of phosphatidylinositol 3, 4, 5-trisphosphate(PIP3), to generate phosphatidylinositol-4, 5,- biphosphate(PIP2). On the other hand, as a protein tyrosine phosphatase, PTEN can dephosphorylate itself, focal adhesion kinase (FAK) and the platelet derived growth factor receptor, involves in the migration, adhension of cells. Many researches have been testified that there is a higher frequency of negative expression of PTEN protein in hepatocellular carcinoma, the negative correlation between expression of PTEN gene and differential grade, clinic stage of HCC indicated that in activation of PTEN gene maybe a late incidence in the development of hepatocellular carcinoma and may play an important role in the genesis and development of some hepatocellular carcinoma. KLF6, a member of Krupple-like gene family, a ubiquitously expressed zinc finger transcription factor, has an important role in regulating cell growth and differentiation. Several experiments have been proved that the genetic events of tumor

  7. Controle do fornecimento e da utilização de substratos energéticos no encéfalo Modulation of energy substrate supply and consumption by the brain

    Directory of Open Access Journals (Sweden)

    A.O. Schelp

    1995-09-01

    érebro (aspartato,gluconato e alanina. Todos podem ser oxidados a CO, e H(20. Entretanto, mesmo com o consumo de glicose reduzido a 50%, a contribuição energética dos aminoácidos não ultrapassa 10%. Para manter o suprimento adequado de glicose e oxigênio, o fluxo sangüíneo cerebral é da ordem de 800 ml/min (15% do débito cardíaco. O consumo de O, pelo cérebro é equivalente a 20% do total consumido pelo corpo. Esses mecanismos, descritos como controladores da utilização de substratos energéticos pelo cérebro, sofrem a influência da idade apenas no período perinatal, com a oxidação do lactato na fase pré-latente e dos corpos cetônicos, no início da amamentação.Altrough accounting for 2% of body weight, brain has one of the greatest metabolic rates compared with other organs and systems. The energy metabolic consum is expended mainly in the maintenance of ionic gradient, essential to neuronal activity. Brain receives energy substrates from circulation, with interference of blood brain barrier (BBB. Glucose is the main substrate and has a metabolic rate so high as 150 g/day (0,7 mM/G/min. At cellular level, metabolism of glucose seems to be controlled by phosphofructokynase. If the cellular level were high enough, manose and other products like fructose 1,6 biphosphate, pyruvate, lactate and acetate can be used in the place of glucose. Lactate, when oxyded, consums at least 21 % of the cerebral needs of 0,. In ischemia and inflammatory infections, brain tissue produces lactate instead of use it. Ketone bodies reduce cerebral needs of glucose; in view of the disturbances that occur in cerebral production of succinyl CoA and guanosine 3 phosphate (GTP, they must be considered as complementary substrate but not as an alternative one. Although they can be metabolized, there are no evidences that brain could produce energy from systemic free fatty acids, even when hypoglicemia is present. Ethanol and glycerol are considered only at experimental level. Brain uptake

  8. The Diversity of Wheat CpFBA Genes and its Responsive to Low Temperature%小麦CpFBA基因的多样性及其对低温处理的响应

    Institute of Scientific and Technical Information of China (English)

    刘迎团; 吕科; 候典云; 黄文达; 花庆; 刘小刚; 刘振兰; 王军卫; 徐虹

    2012-01-01

    Chloroplast fructose-1,6-bisphosphate aldolase (CpFBA, aldolase) is a key enzyme involved in the carbon fixation of Calvin Cycle which is important metabolism pathway in photosynthesis. It has been reported that this enzyme participate in the response to different types of abiotic stresses in land plants. In this article, three cDNA sequences encoding wheat CpFBA (TaCpFBA) were cloned by RACE (Rapid-amplification of cDNA ends) and RT-PCR from winter wheat variety Albinism line, two of these may encode 388 amino acids, the other one encodes 309 amino acids. Another two different cDNA sequences come from the control wheat A ibian 1, which encode 388 and 373 amino acids separately. Two 388 amino acids sequences from different materials are identity. We predicted the sequence has a 37 amino acids chloroplast transit peptide by software online. According the cDNA sequences, two primers were designed to amplify TaCpFBA genomic DNA. A 2 669 bp sequence fromAlbinism line, and a 2 630 bp sequence from Aibian 1 were obtained, both sequences contain 6 exons. The TaCpFBA-eGFP fusion vector was constructed. After the vector was transferred into Arabidopsis protoplasts, the transit expression of TaCpFBA-eGFP fusion gene indicated that the TaCpFBA gene encode a chloroplast protein. Furthermore, the expression pattern of TaCpFBA in cold condition was investigated in albinism line and Aibian 1 by quantitative Real Time PCR. We found that, the TaCpFBA trancription of Aibian 1 rose first and then went down, but in albinism line, the wheat sensitive to low temperature, first decreased obviously, then increased gradually. The results suggested the inconsistent expression of TaCpFBA gene in different cold responsive mechanism.%叶绿体果糖-1,6-二磷酸醛缩酶(chloroplast fructose-1,6-biphosphate aldolase,CpFBA)是Calvin循环碳固定过程中的一个关键酶.该酶在光合作用中具有重要的功能,在一些非生物胁迫响应中也起重要的调控作用.本文用RT

  9. 长期施肥对稻田土壤固碳功能菌群落结构和数量的影响%Abundance and composition of CO2fixating bacteria in relation to long-term fertilization of paddy soils

    Institute of Scientific and Technical Information of China (English)

    袁红朝; 秦红灵; 刘守龙; 童成立; 葛体达; 魏文学; 吴金水

    2012-01-01

    CO2 fixation is the central mechanism of primary production in almost all ecosystems, and plays a major role in regulating the concentration of atmospheric CO2. Carbon dioxide accounts for about 50% of the current global wanning potential. Soil microorganisms that assimilate CO2 are widely distributed, and have a great ability to adapt to environmental extremes, such as within volcanic sediments, lake wetlands and the submarine realm. Microbial CO2 assimilation is of great significance to climate change mitigation and sustainable development for human beings.It has now been well established that atmospheric concentration of CO2 can be reduced significantly by adopting management practices to enhance CO2 sequestration (storage) in cropland soils. Among the approaches for increasing CO2 sequestration of croplands are soil fertilization management practices, such as returning crop residues to the soil, plantingtemporarily retired land with grass for stabilization, and integrating nutrient management strategies to diversified cropping systems.Paddy soils are distributed widely throughout the world, and generally are known for their production of greenhouse gasses ( N2 O and CH4 ). Numerous studies have used molecular techniques to investigate these microbial driving mechanisms. However, few studies have addressed the importance of microbial CO2 fixation processes in paddy soils. Investigation of the impacts of long-term fertilization on the structure and abundance of CO2 assimilating bacteria in paddy soils can provide a theoretical basis for the application of information on fertilization of paddy-rice fields. This type of research also may benefit the reduction of greenhouse gas emissions and increase carbon sequestration.Although carbon fixating microorganisms exhibit a wide range of physiological and ecological traits, most photo- and chemoautotrophic bacteria use ribulose-1,5-biphosphate carboxylase/oxygenase (RubisCO) , which catalyzes the first rate